Systems for sleep disorder detection, analysis, and / or treatment

Abstract

Examples of the disclosure include a system for treating disordered breathing in a patient, including an electrical-pulse generator (IPG) to generate an electrical stimulation and including a controller and a power source, a lead including a first sensor, and a second sensor, the controller being configured to provide, via the lead, first electrical stimulation to a target nerve including a phrenic nerve, receive, from the lead, respiratory information indicative of a respiratory parameter of the patient, determine, based on the respiratory information, a therapy-specific indicator indicative of an effect of the stimulation, receive, from the at least one second sensor, non-respiratory information, determine, based on the non-respiratory information, a patient-specific indicator relating to at least one patient condition, modify, based on at least one of the indicators, at least one parameter of the stimulation, and provide, via the lead, at least one second electrical stimulation having the modified parameter.

Description

[0001] SYSTEMS FOR SLEEP DISORDER DETECTION, ANALYSIS, AND / OR TREATMENT

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to U.S. Provisional Application Serial No. 63 / 456,202, titled “SYSTEMS AND METHODS FOR SLEEP DISORDER DETECTION, ANALYSIS, AND / OR TREATMENT,” filed on March 31, 2023, which is hereby incorporated by reference in its entirety.

[0004] BACKGROUND

[0005] At least one example in accordance with the present disclosure relates generally to sleep disorders.

[0006] SUMMARY

[0007] According to at least one aspect of the present disclosure, a system for treating disordered breathing in a patient is provided, the system including at least one electrical-pulse generator including at least one controller and at least one power source, the electrical-pulse generator being configured to generate at least one electrical stimulation, at least one lead configured to be coupled to the electrical-pulse generator and being configured to be implanted in the patient to deliver the at least one electrical stimulation to a phrenic nerve of the patient and to sense respiratory information, and at least one patient sensor configured to detect at least one non- respiratory parameter of the patient, the at least one controller being configured to provide, via the at least one lead, at least one first electrical stimulation having one or more stimulation parameters to the phrenic nerve of the patient to treat disordered breathing in the patient, receive, from the at least one lead, the respiratory information indicative of at least one respiratory parameter of the patient, determine, based on the respiratory information, a therapy -specific indicator indicative of an effect of the at least one first electrical stimulation on respiration of the patient, receive, from the at least one patient sensor, non-respiratory information indicative of the at least one non-respiratory parameter of the patient, determine, based on the non-respiratory information, a patient- specific indicator relating to at least one condition of the patient, modify, based on at least one of the therapy-specific indicator or the patient- specific indicator, at least one stimulation parameter of the electrical signal, and provide, via the at least one lead, at least one second stimulation signal having the modified at least one stimulation parameter to treat the patient.

[0008] In at least one example, the at least one controller is further configured to receive patientfeedback information from the patient, and modify the at least one stimulation parameter based on the patient-feedback information. In at least one example, modifying the at least one stimulation parameter includes modifying a current level of the at least one first electrical stimulation. In at least one example, modifying the at least one stimulation parameter includes modifying a current level of the at least one first electrical stimulation. In at least one example, modifying the current level of the at least one first electrical stimulation includes increasing the current level of the at least one first electrical stimulation.

[0009] In at least one example, modifying the current level of the at least one first electrical stimulation includes decreasing the current level of the at least one first electrical stimulation. In at least one example, the at least one lead includes one or more electrodes. In at least one example, one or more leads of the at least one lead are configured to be implanted in a lumen proximate the phrenic nerve of the patient. In at least one example, the at least one lead includes one or more nerve cuffs. In at least one example, at least one nerve cuff of the one or more nerve cuffs is configured to be operatively coupled to the phrenic nerve of the patient. In at least one example, treating disordered breathing includes treating central sleep apnea.

[0010] In at least one example, providing the at least one first electrical stimulation causes the diaphragm of the patient to contract. In at least one example, one or more leads of the at least one lead are configured to be implanted in a lumen of the patient. In at least one example, the lumen includes at least one of the right brachiocephalic vein, the left brachiocephalic vein, the superior vena cava, the right internal jugular vein, the left internal jugular vein, the left subclavian vein, the right subclavian vein, the right pericardiophrenic vein, or the left pericardiophrenic vein. In at least one example, the respiratory information is indicative of a breathing rate of the patient. In at least one example, the at least one lead includes a transthoracic impedance sensor.

[0011] In at least one example, the respiratory information is indicative of a lung volume of the patient. In at least one example, the non-respiratory information is indicative of movement of the patient. In at least one example, the movement of the patient is indicative of movement of the chest of the patient caused by the patient breathing. In at least one example, the movement of the patient is indicative of a change in a position of the patient. In at least one example, the position of the patient includes one of a side position, a supine position, a prone position, or a vertical position. In at least one example, the at least one patient sensor includes at least one accelerometer.

[0012] In at least one example, the at least one accelerometer is implanted in the patient. In at least one example, the at least one accelerometer is implanted in the at least one electrical-pulse generator. In at least one example, the at least one accelerometer includes a first accelerometer external to the patient. In at least one example, the at least one accelerometer includes a second accelerometer implanted in the patient. In at least one example, the non-respiratory information is further indicative of a heart rate of the patient. In at least one example, the at least one patient sensor includes an optical sensor. In at least one example, the optical sensor includes a pulse oximeter.

[0013] In at least one example, the at least one patient sensor includes one or more leads to sense electrical activity of the heart of the patient. In at least one example, the non-respiratory information is indicative of a sleep stage of the patient. In at least one example, the at least one patient sensor includes at least one of an accelerometer or a heart-rate sensor. In at least one example, the at least one controller is configured to determine, based on the non-respiratory information, the sleep stage of the patient. In at least one example, the sleep stage includes one of light sleep, deep sleep, and rapid-eye-movement sleep. In at least one example, the non- respiratory information is indicative of a heart rate of the patient.

[0014] In at least one example, the at least one patient sensor includes an optical sensor. In at least one example, the optical sensor includes a pulse oximeter. In at least one example, the at least one patient sensor includes one or more leads to sense electrical activity of the heart of the patient. In at least one example, the non-respiratory information is indicative of a sleep stage of the patient. In at least one example, the at least one patient sensor includes at least one of an accelerometer or a heart-rate sensor. In at least one example, the at least one controller is configured to determine, based on the non-respiratory information, the sleep stage of the patient. In at least one example, the sleep stage includes one of light sleep, deep sleep, and rapid-eye- movement sleep.

[0015] In at least one example, the sleep stage of the patient includes the patient being awake. In at least one example, the at least one controller is further configured to determine, based on the non-respiratory information, that the patient is rolling responsive to providing the at least one first electrical stimulation, and modify the at least one stimulation parameter based on determining that the patient is rolling. In at least one example, modifying the at least one stimulation parameter includes decreasing a current of the at least one first electrical stimulation. In at least one example, the at least one controller is further configured to stop providing stimulation to the at least one lead responsive to determining that the patient is rolling.

[0016] In at least one example, the at least one controller is further configured to resume providing stimulation to the at least one lead responsive to determining that the patient is no longer rolling. In at least one example, the at least one patient sensor includes an accelerometer and the non-respiratory information is indicative of movement of the patient. In at least one example, determining that the patient is rolling responsive to providing the at least one first electrical stimulation includes determining that the patient is moving based on the non- respiratory information, determining whether the patient began moving within a threshold period of time after providing the at least one first electrical stimulation, and determining that the patient moving is caused by the at least one first electrical stimulation responsive to determining that the patient began moving within the threshold period of time.

[0017] In at least one example, the one or more stimulation parameters include at least one of a current level of the at least one first electrical stimulation, a duration of the at least one first electrical stimulation, a number of pulses of the at least one first electrical stimulation, a frequency of pulses of the at least one first electrical stimulation, or a respective current level of each pulse of a plurality of pulses of the at least one first electrical stimulation. In at least one example, the respiratory information is indicative of a lung volume of the patient. In at least one example, the at least one patient sensor includes a transthoracic impedance sensor. In at least one example, the at least one patient sensor includes a plurality of sensors from a list including an accelerometer, a pressure sensor, a transthoracic impedance sensor, an optical sensor, and a heart-rate sensor.

[0018] In at least one example, the therapy- specific indicator is indicative of entrainment of the respiration of the patient to the at least one first electrical stimulation. In at least one example, the patient- specific indicator is indicative of at least one of a position of the patient, movement of the patient, a heart rate of the patient, a change in the heart rate of the patient, a sleep stage of the patient, or a change in the sleep change of the patient, in response to the at least one first electrical stimulation. In at least one example, the at least one patient sensor includes a peripheral arterial tone sensor.

[0019] According to at least one aspect of the disclosure, a system for treating disordered breathing in a patient is provided, the system including at least one electrical-pulse generator including at least one controller and at least one power source, the electrical-pulse generator being configured to generate at least one electrical stimulation, at least one lead configured to be coupled to the electrical-pulse generator and being configured to be implanted in the patient to deliver the at least one electrical stimulation to a phrenic nerve of the patient, at least one respiratory sensor configured to detect at least one respiratory parameter of the patient, and at least one patient sensor configured to detect at least one non-respiratory parameter of the patient, the at least one controller being configured to provide, via the at least one lead, at least one first electrical stimulation having one or more stimulation parameters to the phrenic nerve of the patient to treat disordered breathing in the patient, receive, from the at least one respiratory sensor, respiratory information indicative of the at least one respirator,' parameter of the patient, determine, based on the respiratory information, a therapy- specific indicator indicative of an effect of the at least one first electrical stimulation on respiration of the patient, receive, from the at least one patient sensor, non-respiratory information indicative of the at least one non- respiratory parameter of the patient, determine, based on the non-respiratory information, a patient-specific indicator relating to at least one condition of the patient, modify, based on at least one of the therapy- specific indicator or the patient-specific indicator, at least one stimulation parameter of the electrical signal, and provide, via the at least one lead, at least one second stimulation signal having the modified at least one stimulation parameter to treat the patient.

[0020] In at least one example, the at least one controller is further configured to receive patientfeedback information from the patient, and modify the at least one stimulation parameter based on the patient-feedback information. In at least one example, modifying the at least one stimulation parameter includes modifying a current level of the at least one first electrical stimulation. In at least one example, modifying the current level of the at least one first electrical stimulation includes decreasing the current level of the at least one first electrical stimulation. In at least one example, modifying the at least one stimulation parameter includes modifying a current level of the at least one first electrical stimulation. In at least one example, modifying the current level of the at least one first electrical stimulation includes increasing the current level of the at least one first electrical stimulation.

[0021] In at least one example, modifying the current level of the at least one first electrical stimulation includes decreasing the current level of the at least one first electrical stimulation. In at least one example, the at least one lead includes one or more electrodes. In at least one example, one or more leads of the at least one lead are configured to be implanted in a lumen proximate the phrenic nerve of the patient. In at least one example, the at least one lead includes one or more nerve cuffs. In at least one example, at least one nerve cuff of the one or more nerve cuffs is configured to be operatively coupled to the phrenic nerve of the patient. In at least one example, treating disordered breathing includes treating central sleep apnea.

[0022] In at least one example, providing the at least one first electrical stimulation causes the diaphragm of the patient to contract. In at least one example, one or more leads of the at least one lead are configured to be implanted in a lumen of the patient. In at least one example, the lumen includes at least one of the right brachiocephalic vein, the left brachiocephalic vein, the superior vena cava, the right internal jugular vein, the left internal jugular vein, the left subclavian vein, the right subclavian vein, the right pericardiophrenic vein, or the left pericardiophrenic vein. In at least one example, the respiratory information is indicative of a breathing rate of the patient. In at least one example, the at least one respiratory sensor includes a transthoracic impedance sensor. In at least one example, the respiratory information is indicative of a lung volume of the patient.

[0023] In at least one example, the non-respiratory information is indicative of movement of the patient. In at least one example, the movement of the patient is indicative of movement of the chest of the patient caused by the patient breathing. In at least one example, the movement of the patient is indicative of a change in a position of the patient. In at least one example, the position of the patient includes one of a side position, a supine position, a prone position, or a vertical position. In at least one example, the at least one patient sensor includes at least one accelerometer. In at least one example, the at least one accelerometer is implanted in the patient. In at least one example, the at least one accelerometer is implanted in the at least one electricalpulse generator.

[0024] In at least one example, the at least one accelerometer includes a first accelerometer external to the patient. In at least one example, the at least one accelerometer includes a second accelerometer implanted in the patient. In at least one example, the non-respiratory information is further indicative of a heart rate of the patient. In at least one example, the at least one patient sensor includes an optical sensor. In at least one example, the optical sensor includes a pulse oximeter. In at least one example, the at least one patient sensor includes one or more leads to sense electrical activity of the heart of the patient. In at least one example, the non-respiratory information is indicative of a sleep stage of the patient. In at least one example, the at least one patient sensor includes at least one of an accelerometer or a heart-rate sensor.

[0025] In at least one example, the at least one controller is configured to determine, based on the non-respiratory information, the sleep stage of the patient. In at least one example, the sleep stage includes one of light sleep, deep sleep, and rapid-eye-movement sleep. In at least one example, the non-respiratory information is indicative of a heart rate of the patient. In at least one example, the at least one patient sensor includes an optical sensor. In at least one example, the optical sensor includes a pulse oximeter. In at least one example, the at least one patient sensor includes one or more leads to sense electrical activity of the heart of the patient. In at least one example, the non-respiratory information is indicative of a sleep stage of the patient. In at least one example, the at least one patient sensor includes at least one of an accelerometer or a heartrate sensor.

[0026] In at least one example, the at least one controller is configured to determine, based on the non-respiratory information, the sleep stage of the patient. In at least one example, the sleep stage includes one of light sleep, deep sleep, and rapid-eye-movement sleep. In at least one example, the respiratory information and the non-respiratory information are indicative of an impact of the at least one first electrical stimulation on the patient breathing. In at least one example, the at least one controller is further configured to determine, based on the non- respiratory information, that the patient is rolling responsive to providing the at least one first electrical stimulation, and modify the at least one stimulation parameter based on determining that the patient is rolling.

[0027] In at least one example, modifying the at least one stimulation parameter includes decreasing a current of the at least one first electrical stimulation. In at least one example, the at least one controller is further configured to stop providing stimulation to the at least one lead responsive to determining that the patient is rolling. In at least one example, the at least one controller is further configured to resume providing stimulation to the at least one lead responsive to determining that the patient is no longer rolling. In at least one example, the at least one patient sensor includes an accelerometer and the non-respiratory information is indicative of movement of the patient. In at least one example, determining that the patient is rolling responsive to providing the at least one first electrical stimulation includes determining that the patient is moving based on the non-respiratory information, determining whether the patient began moving within a threshold period of time after providing the at least one first electrical stimulation, and determining that the patient moving is caused by the at least one first electrical stimulation responsive to determining that the patient began moving within the threshold period of time.

[0028] In at least one example, the one or more stimulation parameters include at least one of a current level of the at least one first electrical stimulation, a duration of the at least one first electrical stimulation, a number of pulses of the at least one first electrical stimulation, a frequency of pulses of the at least one first electrical stimulation, or a respective current level of each pulse of a plurality of pulses of the at least one first electrical stimulation. In at least one example, the respiratory information is indicative of a lung volume of the patient. In at least one example, the at least one sensor includes a transthoracic impedance sensor. In at least one example, the at least one patient sensor includes a plurality of sensors from a list including an accelerometer, a pressure sensor, a transthoracic impedance sensor, an optical sensor, and a heart-rate sensor.

[0029] In at least one example, the therapy- specific indicator is indicative of entrainment of the respiration of the patient to the at least one first electrical stimulation. In at least one example, the patient- specific indicator is indicative of at least one of a position of the patient, movement of the patient, a heart rate of the patient, a change in the heart rate of the patient, a sleep stage of the patient, or a change in the sleep change of the patient, in response to the at least one first electrical stimulation. In at least one example, the respiratory information is indicative of a blood-oxygen level of the patient. In at least one example, the respiratory information is indicative of a peripheral oxygen saturation level of the patient. In at least one example, the at least one patient sensor includes a pulse oximeter.

[0030] In at least one example, the respiratory information is indicative of sound produced by the patient breathing. In at least one example, the at least one respiratory sensor includes an acoustic sensor. In at least one example, the respiratory information is indicative of a lung volume of the patient, and wherein the at least one respiratory sensor includes a pressure sensor. In at least one example, the pressure sensor is implanted in the patient. In at least one example, the at least one respiratory sensor includes a near-infrared spectroscopy sensor. In at least one example, the at least one respiratory sensor includes at least one peripheral arterial tone sensor. In at least one example, the at least one respiratory sensor includes at least one flow sensor.

[0031] In at least one example, the at least one respiratory sensor includes at least one pulse oximeter. In at least one example, the at least one respiratory sensor includes at least one acoustic sensor. In at least one example, the respiratory information is indicative of sound produced by the heart of the patient beating.

[0032] According to at least one aspect of the disclosure, a system for treating disordered breathing in a patient is provided, the system including at least one electrical-pulse generator including at least one controller and at least one power source, the electrical-pulse generator being configured to generate at least one electrical stimulation, at least one stimulation lead configured to be coupled to the electrical-pulse generator and being configured to be implanted in the patient to deliver the at least one electrical stimulation to a phrenic nerve of the patient, at least one sensing lead configured to detect at least one respiratory parameter of the patient, and at least one patient sensor configured to detect at least one non-respiratory parameter of the patient, the at least one controller being configured to provide, via the at least one stimulation lead, at least one first electrical stimulation having one or more stimulation parameters to the phrenic nerve of the patient to treat disordered breathing in the patient, receive, from the at least one sensing lead, respiratory information indicative of the at least one respiratory parameter of the patient, determine, based on the respiratory information, a therapy-specific indicator indicative of an effect of the at least one first electrical stimulation on respiration of the patient, receive, from the at least one patient sensor, non-respiratory information indicative of the at least one non- respiratory parameter of the patient, determine, based on the non-respiratory information, a patient-specific indicator relating to at least one condition of the patient, modify, based on at least one of the therapy- specific indicator or the patient-specific indicator, at least one stimulation parameter of the electrical signal, and provide, via the at least one stimulation lead, at least one second stimulation signal having the modified at least one stimulation parameter to treat the patient.

[0033] In at least one example, the at least one controller is further configured to receive patientfeedback information from the patient, and modify the at least one stimulation parameter based on the patient-feedback information. In at least one example, modifying the at least one stimulation parameter includes modifying a current level of the at least one first electrical stimulation. In at least one example, modifying the current level of the at least one first electrical stimulation includes decreasing the current level of the at least one first electrical stimulation. In at least one example, modifying the at least one stimulation parameter includes modifying a current level of the at least one first electrical stimulation. In at least one example, modifying the current level of the at least one first electrical stimulation includes increasing the cunent level of the at least one first electrical stimulation.

[0034] In at least one example, modifying the current level of the at least one first electrical stimulation includes decreasing the current level of the at least one first electrical stimulation. In at least one example, each of the at least one sensing lead and the at least one stimulation lead includes one or more electrodes. In at least one example, one or more leads of the at least one stimulation lead are configured to be implanted in a lumen proximate the phrenic nerve of the patient. In at least one example, the at least one stimulation lead includes one or more nerve cuffs. In at least one example, at least one nerve cuff of the one or more nerve cuffs is configured to be operatively coupled to the phrenic nerve of the patient. In at least one example, treating disordered breathing includes treating central sleep apnea.

[0035] In at least one example, providing the at least one first electrical stimulation causes the diaphragm of the patient to contract. In at least one example, one or more leads of the at least one stimulation lead are configured to be implanted in a lumen of the patient. In at least one example, the lumen includes at least one of the right brachiocephalic vein, the left brachiocephalic vein, the superior vena cava, the right internal jugular vein, the left internal jugular vein, the left subclavian vein, the right subclavian vein, the right pericardiophrenic vein, or the left pericardiophrenic vein. In at least one example, the respiratory information is indicative of a breathing rate of the patient. In at least one example, the at least one sensing lead includes a transthoracic impedance sensor.

[0036] In at least one example, the respiratory information is indicative of a lung volume of the patient. In at least one example, the non-respiratory information is indicative of movement of the patient. In at least one example, the movement of the patient is indicative of movement of the chest of the patient caused by the patient breathing. In at least one example, the movement of the patient is indicative of a change in a position of the patient. In at least one example, the position of the patient includes one of a side position, a supine position, a prone position, or a vertical position. In at least one example, the at least one patient sensor includes at least one accelerometer. In at least one example, the at least one accelerometer is implanted in the patient.

[0037] In at least one example, the at least one accelerometer is implanted in the at least one electrical-pulse generator. In at least one example, the at least one accelerometer includes a first accelerometer external to the patient. In at least one example, the at least one accelerometer includes a second accelerometer implanted in the patient. In at least one example, the non- respiratory information is further indicative of a heart rate of the patient. In at least one example, the at least one patient sensor includes an optical sensor. In at least one example, the optical sensor includes a pulse oximeter. In at least one example, the at least one patient sensor includes one or more leads to sense electrical activity of the heart of the patient. In at least one example, the non-respiratory information is indicative of a sleep stage of the patient.

[0038] In at least one example, the at least one patient sensor includes at least one of an accelerometer or a heart-rate sensor. In at least one example, the at least one controller is configured to determine, based on the non-respiratory information, the sleep stage of the patient. In at least one example, the sleep stage includes one of light sleep, deep sleep, and rapid-eye- movement sleep. In at least one example, the non-respiratory information is indicative of a heart rate of the patient. In at least one example, the at least one patient sensor includes an optical sensor. In at least one example, the optical sensor includes a pulse oximeter. In at least one example, the at least one patient sensor includes one or more leads to sense electrical activity of the heart of the patient. In at least one example, the non-respiratory information is indicative of a sleep stage of the patient.

[0039] In at least one example, the at least one patient sensor includes at least one of an accelerometer or a heart-rate sensor. In at least one example, the at least one controller is configured to determine, based on the non-respiratory information, the sleep stage of the patient. In at least one example, the sleep stage includes one of light sleep, deep sleep, and rapid-eye- movement sleep. In at least one example, the respiratory information and the non-respiratory information are indicative of an impact of the at least one first electrical stimulation on the patient breathing. In at least one example, the at least one controller is further configured to determine, based on the non-respiratory information, that the patient is rolling responsive to providing the at least one first electrical stimulation, and modify the at least one stimulation parameter based on determining that the patient is rolling.

[0040] In at least one example, modifying the at least one stimulation parameter includes decreasing a current of the at least one first electrical stimulation. In at least one example, the at least one controller is further configured to stop providing stimulation to the at least one lead responsive to determining that the patient is rolling. In at least one example, the at least one controller is further configured to resume providing stimulation to the at least one lead responsive to determining that the patient is no longer rolling. In at least one example, the at least one patient sensor includes an accelerometer and the non-respiratory information is indicative of movement of the patient.

[0041] In at least one example, determining that the patient is rolling responsive to providing the at least one first electrical stimulation includes determining that the patient is moving based on the non-respiratory information, determining whether the patient began moving within a threshold period of time after providing the at least one first electrical stimulation, and determining that the patient moving is caused by the at least one first electrical stimulation responsive to determining that the patient began moving within the threshold period of time. In at least one example, the one or more stimulation parameters include at least one of a current level of the at least one first electrical stimulation, a duration of the at least one first electrical stimulation, a number of pulses of the at least one first electrical stimulation, a frequency of pulses of the at least one first electrical stimulation, or a respective current level of each pulse of a plurality of pulses of the at least one first electrical stimulation.

[0042] In at least one example, the respiratory information is indicative of a lung volume of the patient. In at least one example, the at least one sensing lead includes a transthoracic impedance sensor. In at least one example, the at least one patient sensor includes a plurality of sensors from a list including an accelerometer, a pressure sensor, a transthoracic impedance sensor, an optical sensor, and a heart-rate sensor. In at least one example, the therapy- specific indicator is indicative of entrainment of the respiration of the patient to the at least one first electrical stimulation. In at least one example, the patient- specific indicator is indicative of at least one of a position of the patient, movement of the patient, a heart rate of the patient, a change in the heart rate of the patient, a sleep stage of the patient, or a change in the sleep change of the patient, in response to the at least one first electrical stimulation. In at least one example, the at least one patient sensor includes a near-infrared spectroscopy sensor.

[0043] In at least one example, the at least one controller is configured to modify the at least one stimulation parameter of the electrical signal based on the patient- specific indicator. In at least one example, the at least one controller is further configured to modify the at least one stimulation parameter of the electrical signal based on the therapy-specific indicator. In at least one example, the at least one controller is configured to modify the at least one stimulation parameter of the electrical signal based on the therapy-specific indicator.

[0044] Examples of the disclosure include a system for treating disordered breathing in a patient, the system including at least one electrical-pulse generator including at least one controller and at least one power source, the at least one electrical-pulse generator being configured to generate at least one electrical stimulation, at least one lead configured to be coupled to the at least one electrical-pulse generator and being configured to be implanted in the patient to deliver the at least one electrical stimulation to a target nerve of the patient and including at least one first sensor configured to sense physiologic information including respiratory information, the target nerve including a phrenic nerve, and at least one second sensor configured to detect at least one patient parameter including at least one non-respiratory parameter of the patient, the at least one controller being configured to provide, via the at least one lead, at least one first electrical stimulation having one or more stimulation parameters to the target nerve of the patient to treat disordered breathing in the patient, receive, from the at least one lead, the respiratory information indicative of at least one respiratory parameter of the patient, determine, based on the respiratory information, a therapy-specific indicator indicative of an effect of the at least one first electrical stimulation on respiration of the patient, receive, from the at least one second sensor, non- respiratory information indicative of the at least one non-respiratory parameter of the patient, determine, based on the non-respiratory information, a patient-specific indicator relating to at least one condition of the patient, modify, based on at least one of the therapy- specific indicator or the patient-specific indicator, at least one stimulation parameter of the at least one electrical stimulation, and provide, via the at least one lead, at least one second electrical stimulation having the modified at least one stimulation parameter to treat the patient.

[0045] In at least one example, the at least one controller is further configured to: receive patient-feedback information from the patient, and modify the at least one stimulation parameter based on the patient-feedback information. In at least one example, modifying the at least one stimulation parameter includes modifying a current level of the at least one first electrical stimulation. In at least one example, modifying the at least one stimulation parameter includes modifying a current level of the at least one first electrical stimulation. In at least one example, modifying the current level of the at least one first electrical stimulation includes increasing the current level of the at least one first electrical stimulation. In at least one example, modifying the current level of the at least one first electrical stimulation includes decreasing the current level of the at least one first electrical stimulation.

[0046] In at least one example, the at least one lead includes one or more electrodes. In at least one example, one or more leads of the at least one lead are configured to be implanted in a lumen proximate the target nerve of the patient. In at least one example, the at least one lead includes one or more nerve cuffs. In at least one example, at least one nerve cuff of the one or more nerve cuffs is configured to be operatively coupled to the target nerve of the patient. In at least one example, the at least one controller is configured to determine the therapy-specific indicator indicative of the effect of the at least one first electrical stimulation on respiration that includes central sleep apnea events. In at least one example, providing the at least one first electrical stimulation causes the diaphragm of the patient to contract. In at least one example, one or more leads of the at least one lead are configured to be implanted in a lumen of the patient.

[0047] In at least one example, the lumen includes at least one of the right brachiocephalic vein, the left brachiocephalic vein, the superior vena cava, the right internal jugular vein, the left internal jugular vein, the left subclavian vein, the right subclavian vein, the right pericardiophrenic vein, or the left pericardiophrenic vein. In at least one example, the respiratory information is indicative of a breathing rate of the patient. In at least one example, the at least one first sensor includes a transthoracic impedance sensor. In at least one example, the respiratory information is indicative of a lung volume of the patient. In at least one example, the non-respiratory information is indicative of movement of the patient. In at least one example, the movement of the patient is indicative of movement of the chest of the patient caused by the patient breathing. In at least one example, the movement of the patient is indicative of a change in a position of the patient.

[0048] In at least one example, the position of the patient includes one of a side position, a supine position, a prone position, or a vertical position. In at least one example, the at least one second sensor includes at least one accelerometer. In at least one example, the at least one accelerometer is implanted in the patient. In at least one example, the at least one accelerometer is disposed on the at least one electrical-pulse generator. In at least one example, the at least one accelerometer includes a first accelerometer external to the patient. In at least one example, the at least one accelerometer includes a second accelerometer implanted in the patient. In at least one example, the non-respiratory information is further indicative of a heart rate of the patient. In at least one example, the at least one second sensor includes an optical sensor.

[0049] In at least one example, the optical sensor includes a pulse oximeter. In at least one example, the at least one second sensor is disposed on one or more leads and is configured to sense electrical activity of the heart of the patient. In at least one example, the non-respiratory information is indicative of a sleep stage of the patient. In at least one example, the at least one second sensor includes at least one of an accelerometer or a heart-rate sensor. In at least one example, the at least one controller is configured to determine, based on the non-respiratory information, the sleep stage of the patient. In at least one example, the sleep stage includes one of light sleep, deep sleep, and rapid-eye-movement sleep. In at least one example, the non- respiratory information is indicative of a heart rate of the patient.

[0050] In at least one example, the at least one second sensor includes an optical sensor. In at least one example, the optical sensor includes a pulse oximeter. In at least one example, the at least one second sensor includes one or more electrodes configured to sense electrical activity of the heart of the patient. In at least one example, the non-respiratory information is indicative of a sleep stage of the patient. In at least one example, the at least one second sensor includes at least one of an accelerometer or a heart-rate sensor. In at least one example, the at least one controller is configured to determine, based on the non-respiratory information, the sleep stage of the patient. In at least one example, the sleep stage includes one of light sleep, deep sleep, and rapideye-movement sleep. In at least one example, the sleep stage of the patient includes the patient being awake.

[0051] In at least one example, the at least one controller is further configured to determine, based on the non-respiratory information, that the patient is rolling responsive to providing the at least one first electrical stimulation, and modify the at least one stimulation parameter based on determining that the patient is rolling. In at least one example, modifying the at least one stimulation parameter includes decreasing a current of the at least one first electrical stimulation. In at least one example, the at least one controller is further configured to stop providing stimulation to the at least one lead responsive to determining that the patient is rolling. In at least one example, the at least one controller is further configured to resume providing stimulation to the at least one lead responsive to determining that the patient is stationary. In at least one example, the at least one second sensor includes an accelerometer and the non-respiratory information is indicative of movement of the patient.

[0052] In at least one example, determining that the patient is rolling responsive to providing the at least one first electrical stimulation includes determining that the patient is moving based on the non-respiratory information, determining whether the patient began moving within a threshold period of time after providing the at least one first electrical stimulation, and determining that the patient moving is caused by the at least one first electrical stimulation responsive to determining that the patient began moving within the threshold period of time. In at least one example, the one or more stimulation parameters include at least one of a current level of the at least one first electrical stimulation, a pulse duration of the at least one first electrical stimulation, a number of pulses of the at least one first electrical stimulation, a frequency of pulses of the at least one first electrical stimulation, or a respective current level of each pulse of a plurality of pulses of the at least one first electrical stimulation.

[0053] In at least one example, the at least one controller is configured to provide the at least one first electrical stimulation and the at least one second electrical stimulation in a synchronous mode, and modify the pulse duration of the at least one first electrical stimulation. In at least one example, the respiratory information is indicative of a lung volume of the patient. In at least one example, the at least one first sensor includes a transthoracic impedance sensor. In at least one example, the at least one first sensor includes one or more of an accelerometer, a pressure sensor, a transthoracic impedance sensor, a heart-rate sensor, or an electromyography sensor. In at least one example, the at least one second sensor includes one or more of an accelerometer, a pressure sensor, a transthoracic impedance sensor, a heart-rate sensor, or an electromyography sensor.

[0054] In at least one example, the therapy- specific indicator is indicative of entrainment of the respiration of the patient to the at least one first electrical stimulation. In at least one example, the at least one controller is configured to provide the at least one first electrical stimulation and the at least one second electrical stimulation in an asynchronous mode, and modify a current of the at least one electrical stimulation based on the therapy- specific indicator indicative of entrainment. In at least one example, the patient-specific indicator is indicative of at least one of a position of the patient, movement of the patient, a heart rate of the patient, a change in the heart rate of the patient, a sleep stage of the patient, or a change in the sleep change of the patient, in response to the at least one first electrical stimulation. In at least one example, the at least one second sensor includes a peripheral arterial tone sensor.

[0055] In at least one example, the at least one controller is configured to receive the non- respiratory information outside of a therapy window for the patient. In at least one example, the target nerve includes a hypoglossal nerve. In at least one example, the at least one controller is configured to determine the therapy- specific indicator indicative of the effect of the at least on first electrical stimulation on respiration that includes obstructive sleep apnea events. In at least one example, the at least one controller is configured to modify, based on at least one therapyspecific indicator and at least one patient-specific indicator, at least one stimulation parameter of the at least one electrical stimulation. In at least one example, the at least one controller is configured to modify, based on at least two therapy-specific indicators, at least one stimulation parameter of the at least one electrical stimulation.

[0056] In at least one example, the at least one controller is configured to modify, based on at least two patient- specific indicators, at least one stimulation parameter of the at least one electrical stimulation. In at least one example, the at least one controller is configured to automatically modify the at least one stimulation parameter of the at least one electrical stimulation in a closed-loop operation mode based on at least one of the therapy- specific indicator or the patient- specific indicator. In at least one example, the at least one controller includes at least one processor, at least one memory, and power adjusting circuitry. In at least one example, the at least one controller is configured to modify the at least one stimulation parameter of the at least one electrical stimulation to increase the intensity of the at least one electrical stimulation to the phrenic nerve based on the at least one therapy -specific indicator including at least one of flow sensor data indicative of low flow relative to a normal patient, acoustic sensor data indicative of low noise relative to a normal patient, vibration sensor data indicative of low vibration relative to a normal patient, transthoracic impedance sensor data indicative of low transthoracic impedance relative to a normal patient, heart rate sensor data indicative of a variable heart rate relative to a normal patient, electromyography (EMG) sensor data indicative of variable or low EMG signals from the diaphragm relative to a normal patient, or diaphragm motion sensor data indicative of low diaphragm motion relative to a normal patient.

[0057] In at least one example, the target nerve includes a hypoglossal nerve, and wherein the at least one controller is configured to modify the at least one stimulation parameter of the at least one electrical stimulation to increase the intensity of the at least one electrical stimulation to the hypoglossal nerve based on the at least one therapy-specific indicator including at least one of flow sensor data indicative of low flow relative to a normal patient, acoustic sensor data indicative of high noise relative to a normal patient, vibration sensor data indicative of high vibration relative to a normal patient, pressure sensor data indicative high pressure relative to a normal patient, transthoracic impedance sensor data indicative of high transthoracic impedance relative to a normal patient, heart rate sensor data indicative of a variable heart rate relative to a normal patient, peripheral arterial tone sensor data indicative of variable arterial tone data relative to a normal patient, electromyography (EMG) sensor data indicative of variable EMG signals from the diaphragm relative to a normal patient, diaphragm motion sensor data indicative of high diaphragm motion relative to a normal patient, or chest and diaphragm motion sensor data indicative of an out-of-phase relationship between chest and diaphragm motion.

[0058] In at least one example, the at least one controller is configured to modify the at least one stimulation parameter of the at least one electrical stimulation to increase the intensity of the at least one electrical stimulation to the phrenic nerve based on the at least one patient- specific indicator including at least one of sensed patient movement, patient touch or voice feedback, a patient tap on the chest of the patient, a change in sleep state, or a high roll frequency. In at least one example, the physiologic information includes non-respiratory information. In at least one example, the at least one patient parameter includes at least one second respiratory parameter of the patient.

[0059] Examples of the disclosure include a system for treating disordered breathing in a patient, the system including: at least one electrical-pulse generator including at least one controller and at least one power source, the at least one electrical-pulse generator being configured to generate at least one electrical stimulation, at least one lead configured to be coupled to the at least one electrical-pulse generator and being configured to be implanted in the patient to deliver the at least one electrical stimulation to a target nerve of the patient, the target nerve including a phrenic nerve, at least one first sensor configured to detect at least one first patient parameter including at least one respiratory parameter of the patient, and at least one second sensor configured to detect at least one second patient parameter including at least one non-respiratory parameter of the patient, the at least one controller being configured to provide, via the at least one lead, at least one first electrical stimulation having one or more stimulation parameters to the target nerve of the patient to treat disordered breathing in the patient, receive, from the at least one first sensor, respiratory information indicative of the at least one respiratory parameter of the patient, determine, based on the respiratory information, a therapy-specific indicator indicative of an effect of the at least one first electrical stimulation on respiration of the patient, receive, from the at least one second sensor, non-respiratory information indicative of the at least one non- respiratory parameter of the patient, determine, based on the non-respiratory information, a patient-specific indicator relating to at least one condition of the patient, modify, based on at least one of the therapy- specific indicator or the patient-specific indicator, at least one stimulation parameter of the electrical stimulation, and provide, via the at least one lead, at least one second electrical stimulation having the modified at least one stimulation parameter to treat the patient.

[0060] In at least one example, the at least one controller is further configured to receive patientfeedback information from the patient, and modify the at least one stimulation parameter based on the patient-feedback information. In at least one example, modifying the at least one stimulation parameter includes modifying a current level of the at least one first electrical stimulation. In at least one example, modifying the current level of the at least one first electrical stimulation includes decreasing the current level of the at least one first electrical stimulation. In at least one example, modifying the at least one stimulation parameter includes modifying a current level of the at least one first electrical stimulation. In at least one example, modifying the current level of the at least one first electrical stimulation includes increasing the cunent level of the at least one first electrical stimulation.

[0061] In at least one example, modifying the current level of the at least one first electrical stimulation includes decreasing the current level of the at least one first electrical stimulation. In at least one example, the at least one lead includes one or more electrodes. In at least one example, one or more leads of the at least one lead are configured to be implanted in a lumen proximate the target nerve of the patient. In at least one example, the at least one lead includes one or more nerve cuffs. In at least one example, at least one nerve cuff of the one or more nerve cuffs is configured to be operatively coupled to the target nerve of the patient. In at least one example, the at least one controller is configured to determine the therapy-specific indicator indicative of the effect of the at least one first electrical stimulation on respiration that includes central sleep apnea events. In at least one example, providing the at least one first electrical stimulation causes the diaphragm of the patient to contract.

[0062] In at least one example, one or more leads of the at least one lead are configured to be implanted in a lumen of the patient. In at least one example, the lumen includes at least one of the right brachiocephalic vein, the left brachiocephalic vein, the superior vena cava, the right internal jugular vein, the left internal jugular vein, the left subclavian vein, the right subclavian vein, the right pericardiophrenic vein, or the left pericardiophrenic vein. In at least one example, the respiratory information is indicative of a breathing rate of the patient. In at least one example, the at least one first sensor includes a transthoracic impedance sensor. In at least one example, the respiratory information is indicative of a lung volume of the patient. In at least one example, the non-respiratory information is indicative of movement of the patient.

[0063] In at least one example, the movement of the patient is indicative of movement of the chest of the patient caused by the patient breathing. In at least one example, the movement of the patient is indicative of a change in a position of the patient. In at least one example, the position of the patient includes one of a side position, a supine position, a prone position, or a vertical position. In at least one example, the at least one second sensor includes at least one accelerometer. In at least one example, the at least one accelerometer is implanted in the patient. In at least one example, the at least one accelerometer is disposed on the at least one electricalpulse generator. In at least one example, the at least one accelerometer includes a first accelerometer external to the patient. In at least one example, the at least one accelerometer includes a second accelerometer implanted in the patient. In at least one example, the non- respiratory information is further indicative of a heart rate of the patient.

[0064] In at least one example, the at least one second sensor includes an optical sensor. In at least one example, the optical sensor includes a pulse oximeter. In at least one example, the at least one second sensor is disposed on one or more leads and is configured to sense electrical activity of the heart of the patient. In at least one example, the non-respiratory information is indicative of a sleep stage of the patient. In at least one example, the at least one second sensor includes at least one of an accelerometer or a heart-rate sensor. In at least one example, the at least one controller is configured to determine, based on the non-respiratory information, the sleep stage of the patient. In at least one example, the sleep stage includes one of light sleep, deep sleep, and rapid-eye-movement sleep. In at least one example, the non-respiratory information is indicative of a heart rate of the patient.

[0065] In at least one example, the at least one second sensor includes an optical sensor. In at least one example, the optical sensor includes a pulse oximeter. In at least one example, the at least one second sensor is disposed on one or more leads and is configured to sense electrical activity of the heart of the patient. In at least one example, the non-respiratory information is indicative of a sleep stage of the patient. In at least one example, the at least one second sensor includes at least one of an accelerometer or a heart-rate sensor. In at least one example, the at least one controller is configured to determine, based on the non-respiratory information, the sleep stage of the patient. In at least one example, the sleep stage includes one of light sleep, deep sleep, and rapid-eye-movement sleep. In at least one example, the respiratory information and the non-respiratory information are indicative of an impact of the at least one first electrical stimulation on the patient breathing.

[0066] In at least one example, the at least one controller is further configured to determine, based on the non-respiratory information, that the patient is rolling responsive to providing the at least one first electrical stimulation, and modify the at least one stimulation parameter based on determining that the patient is rolling. In at least one example, modifying the at least one stimulation parameter includes decreasing a current of the at least one first electrical stimulation. In at least one example, the at least one controller is further configured to stop providing stimulation to the at least one lead responsive to determining that the patient is rolling. In at least one example, the at least one controller is further configured to resume providing stimulation to the at least one lead responsive to determining that the patient is stationary.

[0067] In at least one example, the at least one second sensor includes an accelerometer and the non-respiratory information is indicative of movement of the patient. In at least one example, determining that the patient is rolling responsive to providing the at least one first electrical stimulation includes determining that the patient is moving based on the non-respiratory information, determining whether the patient began moving within a threshold period of time after providing the at least one first electrical stimulation, and determining that the patient moving is caused by the at least one first electrical stimulation responsive to determining that the patient began moving within the threshold period of time. In at least one example, the one or more stimulation parameters include at least one of a current level of the at least one first electrical stimulation, a pulse duration of the at least one first electrical stimulation, a number of pulses of the at least one first electrical stimulation, a frequency of pulses of the at least one first electrical stimulation, or a respective current level of each pulse of a plurality of pulses of the at least one first electrical stimulation.

[0068] In at least one example, the at least one controller is configured to provide the at least one first electrical stimulation and the at least one second electrical stimulation in a synchronous mode, and modify the pulse duration of the at least one first electrical stimulation. In at least one example, the respiratory information is indicative of a lung volume of the patient. In at least one example, the at least one first sensor includes a transthoracic impedance sensor. In at least one example, at least one of the at least one first sensor or the at least one second sensor includes one or more of an accelerometer, a pressure sensor, a transthoracic impedance sensor, an optical sensor, a heart-rate sensor, or an electromyography sensor. In at least one example, the therapyspecific indicator is indicative of entrainment of the respiration of the patient to the at least one first electrical stimulation.

[0069] In at least one example, the at least one controller is configured to provide the at least one first electrical stimulation and the at least one second electrical stimulation in an asynchronous mode, and modify a current of the at least one electrical stimulation based on the therapy- specific indicator indicative of entrainment. In at least one example, the patient- specific indicator is indicative of at least one of a position of the patient, movement of the patient, a heart rate of the patient, a change in the heart rate of the patient, a sleep stage of the patient, or a change in the sleep change of the patient, in response to the at least one first electrical stimulation. In at least one example, the respiratory information is indicative of a blood-oxygen level of the patient.

[0070] In at least one example, the respiratory information is indicative of a peripheral oxygen saturation level of the patient. In at least one example, the at least one second sensor includes a pulse oximeter. In at least one example, the respiratory information is indicative of sound produced by the patient breathing. In at least one example, the at least one first sensor includes an acoustic sensor. In at least one example, the respiratory information is indicative of a lung volume of the patient, and wherein the at least one first sensor includes a pressure sensor. In at least one example, the pressure sensor is implanted in the patient. In at least one example, the at least one first sensor includes a near-infrared spectroscopy sensor. In at least one example, the at least one first sensor includes at least one peripheral arterial tone sensor.

[0071] In at least one example, the at least one first sensor includes at least one flow sensor. In at least one example, the at least one first sensor includes at least one pulse oximeter. In at least one example, the at least one first sensor includes at least one acoustic sensor. In at least one example, the respiratory information is indicative of sound produced by the heart of the patient beating. In at least one example, the at least one controller is configured to receive the non- respiratory information outside of a therapy window for the patient. In at least one example, the target nerve includes a hypoglossal nerve. In at least one example, the at least one controller is configured to determine the therapy- specific indicator indicative of the effect of the at least on first electrical stimulation on respiration that includes obstructive sleep apnea events. In at least one example, the at least one controller is configured to modify, based on at least one therapyspecific indicator and at least one patient-specific indicator, at least one stimulation parameter of the at least one electrical stimulation.

[0072] In at least one example, the at least one controller is configured to modify, based on at least two therapy-specific indicators, at least one stimulation parameter of the at least one electrical stimulation. In at least one example, the at least one controller is configured to modify, based on at least two patient- specific indicators, at least one stimulation parameter of the at least one electrical stimulation. In at least one example, the at least one controller is configured to automatically modify the at least one stimulation parameter of the at least one electrical stimulation in a closed-loop operation mode based on at least one of the therapy- specific indicator or the patient- specific indicator. In at least one example, the at least one controller includes at least one processor, at least one memory, and power adjusting circuitry.

[0073] In at least one example, the at least one controller is configured to modify the at least one stimulation parameter of the at least one electrical stimulation to increase the intensity of the at least one electrical stimulation to the phrenic nerve based on the at least one therapy- specific indicator including at least one of flow sensor data indicative of low flow relative to a normal patient, acoustic sensor data indicative of low noise relative to a normal patient, vibration sensor data indicative of low vibration relative to a normal patient, transthoracic impedance sensor data indicative of low transthoracic impedance relative to a normal patient, heart rate sensor data indicative of a variable heart rate relative to a normal patient, electromyography (EMG) sensor data indicative of variable or low EMG signals from the diaphragm relative to a normal patient, or diaphragm motion sensor data indicative of low diaphragm motion relative to a normal patient.

[0074] In at least one example, the target nerve includes a hypoglossal nerve, and wherein the at least one controller is configured to modify the at least one stimulation parameter of the at least one electrical stimulation to increase the intensity of the at least one electrical stimulation to the hypoglossal nerve based on the at least one therapy-specific indicator including at least one of flow sensor data indicative of low flow relative to a normal patient, acoustic sensor data indicative of high noise relative to a normal patient, vibration sensor data indicative of high vibration relative to a normal patient, pressure sensor data indicative high pressure relative to a normal patient, transthoracic impedance sensor data indicative of high transthoracic impedance relative to a normal patient, heart rate sensor data indicative of a variable heart rate relative to a normal patient, peripheral arterial tone sensor data indicative of variable arterial tone data relative to a normal patient, electromyography (EMG) sensor data indicative of variable EMG signals from the diaphragm relative to a normal patient, diaphragm motion sensor data indicative of high diaphragm motion relative to a normal patient, or chest and diaphragm motion sensor data indicative of an out-of-phase relationship between chest and diaphragm motion.

[0075] In at least one example, the at least one controller is configured to modify the at least one stimulation parameter of the at least one electrical stimulation to increase the intensity of the at least one electrical stimulation to the phrenic nerve based on the at least one patient- specific indicator including at least one of sensed patient movement, patient touch or voice feedback, a patient tap on the chest of the patient, a change in sleep state, or a high roll frequency. In at least one example, the at least one first patient parameter includes at least one second non-respiratory parameter of the patient. In at least one example, the at least one second patient parameter includes at least one second respiratory parameter of the patient.

[0076] Examples of the disclosure include a system for treating disordered breathing in a patient, the system including: at least one electrical-pulse generator including at least one controller and at least one power source, the at least one electrical-pulse generator being configured to generate at least one electrical stimulation, at least one stimulation lead configured to be coupled to the at least one electrical-pulse generator and being configured to be implanted in the patient to deliver the at least one electrical stimulation to a target nerve of the patient, the target nerve including a phrenic nerve, at least one sensing lead including at least one first sensor and configured to detect at least one first patient parameter including a respirator,' parameter of the patient, and at least one second sensor configured to detect at least one second patient parameter including a non-respiratory parameter of the patient, the at least one controller being configured to provide, via the at least one stimulation lead, at least one first electrical stimulation having one or more stimulation parameters to the target nerve of the patient to treat disordered breathing in the patient, receive, from the at least one sensing lead, respiratory information indicative of the at least one respiratory parameter of the patient, determine, based on the respiratory information, a therapy- specific indicator indicative of an effect of the at least one first electrical stimulation on respiration of the patient, receive, from the at least one second sensor, non-respiratory information indicative of the at least one non-respiratory parameter of the patient, determine, based on the non-respiratory information, a patient- specific indicator relating to at least one condition of the patient, modify, based on at least one of the therapy-specific indicator or the patient-specific indicator, at least one stimulation parameter of the at least one electrical stimulation, and provide, via the at least one stimulation lead, at least one second electrical stimulation having the modified at least one stimulation parameter to treat the patient.

[0077] In at least one example, the at least one controller is further configured to receive patientfeedback information from the patient, and modify the at least one stimulation parameter based on the patient-feedback information. In at least one example, modifying the at least one stimulation parameter includes modifying a current level of the at least one first electrical stimulation. In at least one example, modifying the current level of the at least one first electrical stimulation includes decreasing the current level of the at least one first electrical stimulation. In at least one example, modifying the at least one stimulation parameter includes modifying a current level of the at least one first electrical stimulation. In at least one example, modifying the current level of the at least one first electrical stimulation includes increasing the current level of the at least one first electrical stimulation.

[0078] In at least one example, modifying the current level of the at least one first electrical stimulation includes decreasing the current level of the at least one first electrical stimulation. In at least one example, each of the at least one sensing lead and the at least one stimulation lead includes one or more electrodes. In at least one example, one or more leads of the at least one stimulation lead are configured to be implanted in a lumen proximate the target nerve of the patient. In at least one example, the at least one stimulation lead includes one or more nerve cuffs. In at least one example, at least one nerve cuff of the one or more nerve cuffs is configured to be operatively coupled to the target nerve of the patient. In at least one example, the at least one controller is configured to determine the therapy-specific indicator indicative of the effect of the at least one first electrical stimulation on respiration that includes central sleep apnea. In at least one example, providing the at least one first electrical stimulation causes the diaphragm of the patient to contract.

[0079] In at least one example, one or more leads of the at least one stimulation lead are configured to be implanted in a lumen of the patient. In at least one example, the lumen includes at least one of the right brachiocephalic vein, the left brachiocephalic vein, the superior vena cava, the right internal jugular vein, the left internal jugular vein, the left subclavian vein, the right subclavian vein, the right pericardiophrenic vein, or the left pericardiophrenic vein. In at least one example, the respiratory information is indicative of a breathing rate of the patient. In at least one example, the at least one first sensor includes a transthoracic impedance sensor. In at least one example, the respiratory information is indicative of a lung volume of the patient. In at least one example, the non-respiratory information is indicative of movement of the patient.

[0080] In at least one example, the movement of the patient is indicative of movement of the chest of the patient caused by the patient breathing. In at least one example, the movement of the patient is indicative of a change in a position of the patient. In at least one example, the position of the patient includes one of a side position, a supine position, a prone position, or a vertical position. In at least one example, the at least one second sensor includes at least one accelerometer. In at least one example, the at least one accelerometer is implanted in the patient. In at least one example, the at least one accelerometer is disposed on the at least one electricalpulse generator. In at least one example, the at least one accelerometer includes a first accelerometer external to the patient. In at least one example, the at least one accelerometer includes a second accelerometer implanted in the patient. In at least one example, the non- respiratory information is further indicative of a heart rate of the patient.

[0081] In at least one example, the at least one second sensor includes an optical sensor. In at least one example, the optical sensor includes a pulse oximeter. In at least one example, the at least one second sensor is disposed on one or more leads and is configured to sense electrical activity of the heart of the patient. In at least one example, the non-respiratory information is indicative of a sleep stage of the patient. In at least one example, the at least one second sensor includes at least one of an accelerometer or a heart-rate sensor. In at least one example, the at least one controller is configured to determine, based on the non-respiratory information, the sleep stage of the patient. In at least one example, the sleep stage includes one of light sleep, deep sleep, and rapid-eye-movement sleep. In at least one example, the non-respiratory information is indicative of a heart rate of the patient. In at least one example, the at least one second sensor includes an optical sensor.

[0082] In at least one example, the optical sensor includes a pulse oximeter. In at least one example, the at least one second sensor is disposed on one or more leads and is configured to sense electrical activity of the heart of the patient. In at least one example, the non-respiratory information is indicative of a sleep stage of the patient. In at least one example, the at least one second sensor includes at least one of an accelerometer or a heart-rate sensor. In at least one example, the at least one controller is configured to determine, based on the non-respiratory information, the sleep stage of the patient. In at least one example, the sleep stage includes one of light sleep, deep sleep, and rapid-eye-movement sleep. In at least one example, the respiratory information and the non-respiratory information are indicative of an impact of the at least one first electrical stimulation on the patient breathing. In at least one example, the at least one controller is further configured to determine, based on the non-respiratory information, that the patient is rolling responsive to providing the at least one first electrical stimulation, and modify the at least one stimulation parameter based on determining that the patient is rolling.

[0083] In at least one example, modifying the at least one stimulation parameter includes decreasing a current of the at least one first electrical stimulation. In at least one example, the at least one controller is further configured to stop providing stimulation to the at least one lead responsive to determining that the patient is rolling. In at least one example, the at least one controller is further configured to resume providing stimulation to the at least one lead responsive to determining that the patient is stationary. In at least one example, the at least one second sensor includes an accelerometer and the non-respiratory information is indicative of movement of the patient. In at least one example, determining that the patient is rolling responsive to providing the at least one first electrical stimulation includes determining that the patient is moving based on the non-respiratory information, determining whether the patient began moving within a threshold period of time after providing the at least one first electrical stimulation, and determining that the patient moving is caused by the at least one first electrical stimulation responsive to determining that the patient began moving within the threshold period of time.

[0084] In at least one example, the one or more stimulation parameters include at least one of a current level of the at least one first electrical stimulation, a pulse duration of the at least one first electrical stimulation, a number of pulses of the at least one first electrical stimulation, a frequency of pulses of the at least one first electrical stimulation, or a respective current level of each pulse of a plurality of pulses of the at least one first electrical stimulation. In at least one example, the at least one controller is configured to provide the at least one first electrical stimulation and the at least one second electrical stimulation in a synchronous mode, and modify the pulse duration of the at least one first electrical stimulation. In at least one example, the respiratory information is indicative of a lung volume of the patient. In at least one example, the at least one first sensor includes a transthoracic impedance sensor. In at least one example, the at least one second sensor includes two or more of an accelerometer, a pressure sensor, a transthoracic impedance sensor, an optical sensor, or a heart-rate sensor.

[0085] In at least one example, the therapy- specific indicator is indicative of entrainment of the respiration of the patient to the at least one first electrical stimulation. In at least one example, the at least one controller is configured to provide the at least one first electrical stimulation and the at least one second electrical stimulation in an asynchronous mode, and modify a current of the electrical stimulation based on the therapy-specific indicator indicative of entrainment. In at least one example, the patient-specific indicator is indicative of at least one of a position of the patient, movement of the patient, a heart rate of the patient, a change in the heart rate of the patient, a sleep stage of the patient, or a change in the sleep change of the patient, in response to the at least one first electrical stimulation.

[0086] In at least one example, the at least one second sensor includes a near-infrared spectroscopy sensor. In at least one example, the at least one controller is configured to receive the non-respiratory information outside of a therapy window for the patient. In at least one example, the target nerve includes a hypoglossal nerve. In at least one example, the at least one controller is configured to determine the therapy- specific indicator indicative of the effect of the at least on first electrical stimulation on respiration that includes obstructive sleep apnea events. In at least one example, the at least one controller is configured to modify, based on at least one therapy- specific indicator and at least one patient- specific indicator, at least one stimulation parameter of the at least one electrical stimulation.

[0087] In at least one example, the at least one controller is configured to modify, based on at least two therapy-specific indicators, at least one stimulation parameter of the at least one electrical stimulation. In at least one example, the at least one controller is configured to modify, based on at least two patient- specific indicators, at least one stimulation parameter of the at least one electrical stimulation. In at least one example, the at least one controller is configured to automatically modify the at least one stimulation parameter of the at least one electrical stimulation in a closed-loop operation mode based on at least one of the therapy- specific indicator or the patient- specific indicator. In at least one example, the at least one controller includes at least one processor, at least one memory, and power adjusting circuitry.

[0088] In at least one example, the at least one controller is configured to modify the at least one stimulation parameter of the at least one electrical stimulation to increase the intensity of the at least one electrical stimulation to the phrenic nerve based on the at least one therapy- specific indicator including at least one of flow sensor data indicative of low flow relative to a normal patient, acoustic sensor data indicative of low noise relative to a normal patient, vibration sensor data indicative of low vibration relative to a normal patient, transthoracic impedance sensor data indicative of low transthoracic impedance relative to a normal patient, heart rate sensor data indicative of a variable heart rate relative to a normal patient, electromyography (EMG) sensor data indicative of variable or low EMG signals from the diaphragm relative to a normal patient, or diaphragm motion sensor data indicative of low diaphragm motion relative to a normal patient.

[0089] In at least one example, the target nerve includes a hypoglossal nerve, and wherein the at least one controller is configured to modify the at least one stimulation parameter of the at least one electrical stimulation to increase the intensity of the at least one electrical stimulation to the hypoglossal nerve based on the at least one therapy-specific indicator including at least one of flow sensor data indicative of low flow relative to a normal patient, acoustic sensor data indicative of high noise relative to a normal patient, vibration sensor data indicative of high vibration relative to a normal patient, pressure sensor data indicative high pressure relative to a normal patient, transthoracic impedance sensor data indicative of high transthoracic impedance relative to a normal patient, heart rate sensor data indicative of a variable heart rate relative to a normal patient, peripheral arterial tone sensor data indicative of variable arterial tone data relative to a normal patient, electromyography (EMG) sensor data indicative of variable EMG signals from the diaphragm relative to a normal patient, diaphragm motion sensor data indicative of high diaphragm motion relative to a normal patient, or chest and diaphragm motion sensor data indicative of an out-of-phase relationship between chest and diaphragm motion.

[0090] In at least one example, the at least one controller is configured to modify the at least one stimulation parameter of the at least one electrical stimulation to increase the intensity of the at least one electrical stimulation to the phrenic nerve based on the at least one patient- specific indicator including at least one of sensed patient movement, patient touch or voice feedback, a patient tap on the chest of the patient, a change in sleep state, or a high roll frequency. In at least one example, the at least one first sensor includes one or more of an accelerometer, a pressure sensor, a transthoracic impedance sensor, a heart-rate sensor, or an electromyography sensor. In at least one example, the at least one second sensor includes one or more of an accelerometer, a pressure sensor, a transthoracic impedance sensor, a heart-rate sensor, or an electromyography sensor. In at least one example, the at least one first patient parameter includes at least one non- respiratory parameter of the patient. In at least one example, the at least one second patient parameter includes at least one respiratory parameter of the patient.

[0091] BRIEF DESCRIPTION OF THE DRAWINGS

[0092] Various aspects of at least one embodiment are discussed below with reference to the accompanying figures, which are not intended to be drawn to scale. The figures are included to provide an illustration and a further understanding of the various aspects and embodiments, and are incorporated in and constitute a part of this specification, but are not intended as a definition of the limits of any particular embodiment. The drawings, together with the remainder of the specification, serve to explain principles and operations of the described and claimed aspects and embodiments. In the figures, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every figure. In the figures:

[0093] FIG. 1A illustrates a disordered-breathing treatment system implanted in a patient according to an example; FIG. IB illustrates a portion of the disordered-breathing treatment system according to an example;

[0094] FIG. 2 illustrates a block diagram of a computing device according to an example;

[0095] FIG. 3 illustrates a process of operating the treatment system according to an example;

[0096] FIG. 4 illustrates a process for determining whether to pause electrical stimulation to the patient according to an example;

[0097] FIG. 5 illustrates a process of performing a calibration procedure according to an example;

[0098] FIG. 6 illustrates a process of operating the treatment system according to another example;

[0099] FIG. 7 illustrates a process of determining additional therapy-effectiveness information according to an example;

[0100] FIGS. 8 A, 8B, and 8C illustrate a process for determining additional sensed information according to an example;

[0101] FIG. 9 illustrates a process of operating the treatment system to provide treatment to the patient according to an example;

[0102] FIG. 10 illustrates a process of operating the treatment system to provide treatment to the patient according to another example;

[0103] FIG. 11 illustrates a process of operating the treatment system to provide treatment to the patient according to another example;

[0104] FIG. 12 illustrates a process of operating the treatment system according to provide treatment to the patient according to another example;

[0105] FIG. 13 illustrates a process of operating the treatment system according to provide treatment to the patient according to another example;

[0106] FIG. 14 illustrates a process of operating the treatment system according to provide treatment to the patient according to another example;

[0107] FIG. 15 illustrates a process of operating the treatment system according to provide treatment to the patient according to another example;

[0108] FIG. 16 illustrates a process operating the treatment system according to provide treatment to the patient according to another example; and FIG. 17 illustrates a graphical depiction of an electrical stimulation pulse train according to an example.

[0109] DETAILED DESCRIPTION

[0110] Examples of the methods and systems discussed herein are not limited in application to the details of construction and the arrangement of components set forth in the following description or illustrated in the accompanying drawings. The methods and systems are capable of implementation in other embodiments and of being practiced or of being carried out in various ways. Examples of specific implementations are provided herein for illustrative purposes only and are not intended to be limiting. In particular, acts, components, elements and features discussed in connection with any one or more examples are not intended to be excluded from a similar role in any other examples.

[0111] Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Any references to examples, embodiments, components, elements or acts of the systems and methods herein referred to in the singular may also embrace embodiments including a plurality, and any references in plural to any embodiment, component, element or act herein may also embrace embodiments including only a singularity. References in the singular or plural form are not intended to limit the presently disclosed systems or methods, their components, acts, or elements. The use herein of “including,” “comprising,” “having,” “containing,” “involving,” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

[0112] References to “or” may be construed as inclusive so that any terms described using “or” may indicate any of a single, more than one, and all of the described terms. In addition, in the event of inconsistent usages of terms between this document and documents incorporated herein by reference, the term usage in the incorporated features is supplementary to that of this document; for irreconcilable differences, the term usage in this document controls.

[0113] Respiration in animals is subject to both voluntary and involuntary control and several disease processes can have a profound impact on respiration. The autonomic nervous system regulates involuntary physiological processes, including respiration, providing sensory input and motor output to the central nervous system. The central nervous system commands the diaphragm and other muscles in the chest and neck to physically contract and relax, thus stimulating breathing. The central nervous system thus acts as a respiratory pacemaker by setting the breathing rate. In a normal sleeping person, the next breath may be initiated after (for example, substantially immediately after) the previous breath is exhaled. Breathing may be characterized by a certain pattern, tidal volume (for example, the volume of air inspired or expired during a respiratory cycle) of each breath and / or breathing rate.

[0114] Disordered breathing is used to describe a variety of observable respiration patterns that deviate from normal respiration patterns. For example, sleep apnea is a breathing-related sleep disorder. Typically, apneas disrupt sleep because patients awaken or are aroused as a result of the apnea event. Sleep apnea exists in several forms, including central sleep apnea (CSA) and obstructive sleep apnea (OSA). CSA involves a reduction in respiratory drive and breathing patterns generally characterized by periods of apnea or hypopnea alternating with hyperpnea.

[0115] OSA involves at least a partial obstruction of the pulmonary airways resulting in a reduction or prevention of air flow. For example, an individual’s tongue — the movement of which may be controlled by one or more nerves, such as hypoglossal nerves — may retract back during sleep and at least partially obstruct the individual’s airway. Electrical stimulation of the hypoglossal nerve and / or another upper airway nerve may provide therapy for reduced airway patency.

[0116] Individuals experiencing sleep apneas or sleep disordered breathing may exhibit various symptoms such as snoring, gasping for breath during sleep, awakening with a dry mouth or headache, insomnia, hypersomnia, difficulty paying attention while awake, visibly experiencing episodes during which the individual stops breathing (which may, for example, be observed by another individual), and so forth. A doctor may diagnose sleep apnea with any of various tests including, for example, nocturnal polysomnography or home sleep tests. Nocturnal polysomnography involves measuring an individual’s heart, lung, and brain activity during sleep, as well as breathing patterns, body movements, and blood-oxygen levels. Irregularities in one or more of these metrics may indicate that an individual is experiencing sleep apnea. Home sleep tests may involve measuring a reduced set of metrics, such as heart rate, blood-oxygen level, and airflow and breathing patterns.

[0117] Sleep apnea may exacerbate, or be exacerbated by, other conditions such as congestive heart failure (CHF). In patients with CHF, prognosis is significantly worse when sleep apnea is present. A high apnea-hypopnea index (AHI) (that is, a measure of the number of breathing disturbances per hour) has been found to correlate to a poor prognosis for the patient for example, due to large swings in arterial blood gases (that is, oxygen and carbon dioxide), arousals and shifts to light sleep, and large negative swings in intrathoracic pressure. These physiological conditions may cause significant deterioration in a patient’s condition over time.

[0118] It has been shown that electrical stimulation of various target nerves can restore normal breathing patterns for patients with sleep disordered breathing. For example, stimulation of the phrenic nerve may contract the diaphragm as therapy for CSA and stimulation of the hypoglossal nerve may contract one or more upper airway muscles as therapy for OSA.

[0119] FIG. 1A illustrates a disordered-breathing treatment system 10 implanted in a patient 20 according to one example. The treatment system 10 can be any suitably configured treatment system implantable in a patient for treating disordered-breathing conditions. By way of example, treatment system 10 can have features as described in any of U.S. Patent No. 8,909,341 titled DEVICE AND METHOD FOR THE TREATMENT OF BREATHING DISORDERS AND CARDIAC DISORDERS; U.S. Patent No. 8,233,987 titled RESPIRATORY RECTIFICATION; U.S. Patent No. 8,433,412 titled MUSCLE AND NERVE STIMULATION; U.S. Patent No. 8,244,359 titled SYSTEM AND METHOD TO MODULATE PHRENIC NERVE TO PREVENT SLEEP APNEA; U.S. Patent No. 10,406,366 titled TRANSVENOUS PHRENIC NERVE STIMULATION SYSTEM; U.S. Patent No. 9,744,351 titled DEVICE AND METHOD FOR THE TREATMENT OF BREATHING DISORDERS AND CARDIAC DISORDERS; U.S. Patent No. 9,987,488 titled DETECTING AND TREATING DISORDERED BREATHING; and so forth.

[0120] In some examples, the treatment system 10 includes a battery-powered pulse generator 12 (IPG 12) which is placed under the skin in the upper chest area 98 (thoracic region) of the patient 20. Accordingly, the treatment system 10 may be considered to be implantable. The IPG 12 is configured to couple to, and may be implanted with, one or more leads 14 and 16. The leads 14 and 16 may be thin conductors, such as wires, coupled to and / or including one or more electrodes. The one or more leads 14 may be used to stimulate, via at least one electrode, one or more nerves of the patient. For example, the leads 14 may be used to stimulate a nerve in the chest, such as the phrenic nerve and / or an upper airway nerve, such as the hypoglossal nerve, located in the upper airway region 97 of the patient. Stimulation of the phrenic nerve may modulate the diaphragm located in the abdominal region 99 of the patient. Stimulation of the hypoglossal nerve may modulate various upper airway muscles including but not limited to muscles of the tongue and may modulate airway patency. In another example, the one or more leads 14 may include or be coupled to one or more nerve cuffs in lieu of, or in addition to, electrodes, as discussed in greater detail below. The IPG 12 may generate the stimulation pulses used to stimulate the one or more nerves of the patient and provide the stimulation pulses to the one or more leads 14.

[0121] The treatment system 10 may be used to provide electrical stimulation of a target nerve in order to restore normal breathing patterns in patients with sleep disordered breathing. The treatment system 10 may include and / or be coupled to one or more sensors 18 to sense information about the patient 20 and / or treatment provided by the treatment system 10, and evaluate and / or modify the treatment based on the information. Although shown outside of the patient 20 in FIG. 1A for simplicity, the sensor(s) 18 (for example, at least one first sensor and at least one second sensor) may include sensors implanted inside of the patient and / or sensors disposed externally on or near the patient. Although the leads 14 and 16 are illustrated as being separate from the sensor(s) 18, the leads 14 and / or 16 may include or be coupled to one or more of the sensor(s) 18 in some examples. The treatment system 10 may further include an external computer 100 configured to communicate via a wireless communication link 30 with the IPG 12.

[0122] In various examples, the treatment system 10 includes one or more controllers and / or processors configured to process information and control operation of the treatment system 10, such as by delivering and modifying the treatment. Accordingly, when the treatment system 10 or IPG 12 are described as determining information or parameters, executing operations such as comparing values to thresholds, modifying parameters for electrical stimulation, sensing or obtaining parameters or information, and so forth, it is to be appreciated that the one or more controllers and / or processors of the treatment system 10 or IPG 12 may be performing these operations.

[0123] For example, as illustrated in FIG. IB, the IPG 12 may include at least one embedded controller 50 that includes at least one or more processors 52, at least one memory 54, at least one power source 56 (for example, a battery), and power adjusting circuitry 58. The one or more processors 52 may be configured to control the power adjusting circuitry 58 in order to modulate the electrical stimulation. The IPG 12 may therefore act as an electrical-pulse generator at least because the power adjusting circuitry 58 may modulate the electrical stimulation. The processor 52 is an embedded processor within the IPG 12, and therefore implanted in the patient, in contrast to the processor 102 of the computing device 100 which is external to the patient.

[0124] As noted above, although the sensor(s) 18 are illustrated as being separate from the leads 14 and 16, in some examples the sensor(s) 18 may refer to sensors disposed on or otherwise coupled to sensing leads and / or stimulation leads. Thus, one or more of the leads 14 and / or 16 may include one or more of the sensor(s) 18. The sensor(s) 18 may provide sensed information to the IPG 12, such as therapy-specific indicator data and / or patient-specific indicator data. In some examples, the sensor(s) 18 may include at least one respiratory sensor configured to sense respiratory information (for example, at least one first sensor). The therapy- specific indicator data may include, and / or be based on, the respiratory information. The sensor(s) 18 may additionally or alternatively include at least one sensor configured to sense non-respiratory information (for example, at least one second sensor). In some examples, the patient-specific indicator data may include, and / or be based on, the non-respiratory information.

[0125] Accordingly, the treatment system 10 may be used to provide electrical stimulation of the phrenic nerve via the one or more leads 14 and thereby treat CSA by restoring normal breathing patterns. Although examples are provided with respect to the phrenic nerve, diaphragm, and CSA, the principles of the disclosure are applicable to providing electrical stimulation to one or more of various target nerves (including, but not limited to, the phrenic nerve and the hypoglossal nerve, to stimulate one or more various muscles (including, but not limited to, the diaphragm and upper airway muscles), and to treat one or more of various conditions (including, but not limited to, CSA, OSA, and other types of breathing disorders).

[0126] The IPG 12 may include, and / or be coupled to, one or more sensors 18 (sensors 18). The sensors 18 may be implanted in the patient 20 and / or may be external to the patient 20. For example, one or more implanted sensors of the sensors 18 may be implanted in the patient 20, and / or one or more external sensors of the sensors 18 may be external to the patient 20. The sensors 18 may include any type and / or number of sensors. In some examples, leads 14 and / or 16 may include one or more of the sensors 18, whereas in other examples, the sensors 18 may be separate from the leads 14 and / or 16. In various examples, the sensors 18 may be configured to sense information indicative of treatment provided by the treatment system 10, respiration of the patient 20, information related to the respiration of the patient 20, and so forth. Examples of particular types of sensors are provided below. In some examples, the lead 14 may be a dedicated stimulation lead and the lead 16 may be a dedicated sensing lead. In such examples, the lead 14 may include stimulation electrodes but exclude sensing electrodes and / or other sensors, and the lead 16 may include sensing electrodes and / or other sensors and exclude stimulation electrodes.

[0127] In various examples, the one or more leads 14 may be an intravascular stimulation lead placed proximate a nerve in the chest (for example, the phrenic nerve) to send signals from the IPG 12 to muscles that control breathing (for example, the diaphragm). The lead 16 may include a transthoracic lead placed to measure transthoracic impedance such that the lead 16 acts as a transthoracic impedance sensor to sense physiological signals such as breathing, fluid state, pulse rate, and so forth. Aspects of the one or more leads 14 are described below for purposes of explanation. Examples herein may refer to the one or more leads 14 in singular form (the lead 14) for simplicity but such examples are not limited to a single lead and may include one or more leads 14. Similar principles may be applicable to the one or more leads 16 (which may be referred to as the lead 16 for simplicity), but may not be repeated for purposes of brevity.

[0128] In various examples, the lead 14 is inserted through the brachiocephalic vein into the ostium of the left pericardiophrenic vein. The lead 14 may include or be coupled to one or more electrodes which can deliver electrical stimulation to the phrenic nerve, which courses parallel to the pericardiophrenic vein in the human body. The one or more electrodes may include ring electrodes extending around a circumference of the lead 14. This half of the branching phrenic nerve may terminate in the hemidiaphragm. In various examples, therefore, after implantation, the lead 14 delivers electrical stimulation to the phrenic nerve to regulate diaphragm motion by the delivery of electrical energy. In this fashion the lead 14 may be used for stimulating the phrenic nerve of a patient to treat defects in respiration. In other examples, the lead 14 may include or be coupled to one or more nerve cuffs disposed around, and operatively coupled to, the phrenic nerve. The lead 16 may differ from the lead 14 in these respects inasmuch as the lead 16 may be external to the patient 20 in various examples, such as by being coupled to the chest of the patient 20, whereas the lead 14 may be implanted in the patient 20. In other examples, both of the leads 14, 16 may be implanted within the patient 20. In an example, the leads 14 may be proximate to and / or operatively coupled to one or more hypoglossal nerves of the patient such that electrical current provided by the IPG 12 conveys an electrical stimulation to the one or more hypoglossal nerves. The lead 14 may be formed of polyurethane or other biocompatible and suitable material. The lead 14 may have a first end, referred to as a proximal portion, and a second end, referred to as a distal portion. In some examples, the distal portion of the lead 14 may be made more stiff or inflexible to retain preformed biases or for increased durability, for example. The proximal portion may be made more flexible so that it does not exert or transmit excess force to the fixated end of the lead 14 or for other reasons.

[0129] Electrodes may include any of various electrodes, such as ring electrodes (that is, electrodes spanning around a circumference of the lead) or other types of electrodes. In some examples, a lead may include a single electrode. In other examples, a lead may include multiple electrodes. A position of the electrode(s) may be selected to correspond to a position of a target tissue relative to the lead when the lead is implanted such that an electrical stimulation applied to the electrode is provided to the target tissue. In some examples, multiple electrodes may be positioned close together in a location corresponding to a position of the target tissue. For example, when viewing a radial cross-section of a spiral or coiled portion of a lead, it may be advantageous for all of the electrodes of the lead to be located within a single quadrant of the radial cross-section.

[0130] In some examples, the lead 14 may include or be coupled to stimulation-delivery elements in addition to, or alternative to, electrodes. For example, the lead 14 may include or be coupled to one or more nerve cuffs. In various examples, nerve cuffs are configured to be implanted in the patient 20. A nerve cuff may be implemented around a target nerve, such as a phrenic nerve. In some examples, a nerve cuff may be implemented only around a target nerve. In other examples, a nerve cuff may be larger, and may surround an entire artery, vein, and / or nerve complex that a target nerve runs inside of. Once implanted, the nerve cuff may be disposed circumferentially around a target nerve, such as a phrenic nerve or hypoglossal nerve. The nerve cuff may be considered to be operatively coupled to the target nerve. As used herein, being operatively coupled may describe a relationship between a nerve cuff and a target nerve in which electrical stimulation provided by the nerve cuff stimulates the target nerve, for example by at least a threshold amount of stimulation. The threshold amount of stimulation for the phrenic nerve may correspond to a level at which an electrical stimulation output by the nerve cuff actuates the muscle innervated by the nerve. For example, a nerve cuff disposed around the phrenic nerve may be operatively coupled to the phrenic nerve where an electrical stimulation provided by the nerve cuff to the phrenic nerve causes the diaphragm to contract.

[0131] In some examples, the lead 14 may include multiple leads. A first group of one or more leads of the lead 14 may include, or be coupled to, electrodes. The first group may be implanted in a lumen of the patient 20 to provide transvenous stimulation of a target nerve. A second group of one or more leads of the lead 14 may include, or be coupled to, nerve cuffs. The second group may be implanted such that the nerve cuffs are operationally coupled to one or more target nerves.

[0132] The lead 16 may be used to sense one or more properties indicative of respiration of an individual in which the lead 16 is implanted, such as respiratory rate (or breathing rate), lung volume, tidal volume, cyclic changes of tidal volume (crescendo-decrescendo), and periodicity of respiration. The lead 16 may include one or more sensors and / or one or more electrodes configured as sensors (as opposed to stimulation electrodes) and may thus sense information, such as a transthoracic impedance, indicative of any of the foregoing properties. Accordingly, the lead 16 may be referred to as a respiration sensor. In some examples, the lead 16 may be considered to be part of the sensors 18. A respiratory waveform can be acquired and stored based on the information provided by the lead 16. The respiratory waveform may be analyzed to determine parameters of a breath such as the breath phase (inspiration or expiration) and tidal volume. The therapy may be applied (for example, via the lead 14) to a target nerve at an appropriate time, which may or may not be synchronized with sensed respiration. In various examples, the implanted system 10 may provide stimulation therapy in an asynchronous mode or a synchronous mode. The asynchronous mode is a mode of therapy delivery in which the stimulation rate is pre-determined and stimulation is not triggered by sensed respiration. Therefore, the stimulation is considered to be asynchronous with the patient’ s intrinsic breathing rate but synchronized with the stimulation rate. In an implementation, the IPG 12 may determine the stimulation rate based on a therapy -specific indicator indicative of entrainment (for example, the capture index as described in more detail below). The synchronous mode is a respiration- triggered mode in which the stimulations are triggered by sensed respiration. Stimulation may thus be synchronized to a patient’ s intrinsic breathing rate.

[0133] Modification of the electrical stimulation therapy by the IPG 12 as discussed herein may depend on the therapy mode. For example, the IPG 12 may modify the therapy based on the therapy- specific indicator of capture index (described in more detail below) in the asynchronous mode but not in the synchronous mode. In this mode, the IPG 12 may modify electricalstimulation current to modify therapy. As another example, the IPG 12 may modify pulse duration for the electrical stimulation signal to modify therapy in the synchronous mode.

[0134] The IPG 12 may provide the electrical stimulation as a pulse train, for example, as described with regard to FIG. 17 below. Modification of the electrical stimulation therapy may include modification of one or more parameters to increase or decrease the stimulation energy provided by the electrical stimulation. The one or more parameters may include one or more of a duration of a ramping-up period and / or an amount by which to increase the energy during the ramping-up period, a duration of a ramping-down period and / or an amount by which to decrease the energy during the ramping-down period, a duration of a time between ramping-up and / or - down periods during which energy is maintained, a pulse amplitude, a number of pulses in a pulse train, a pulse width of the pulses, a time between pulse trains, a waveform of each pulse, a frequency of pulses, a pulse amplitude, a maximum and / or minimum pulse amplitude, a stimulation current, a stimulation voltage, a stimulation polarity (for example, monophasic or biphasic), or any other parameters affecting how the IPG 12 delivers the stimulation energy to the patient.

[0135] Breathing parameters such as respiratory rate, tidal volume, cyclic changes of tidal volume (crescendo-decrescendo), and periodicity of respiration may be determined based on information received from the lead 14 and / or 16 and therapy may be modified based at least in part on the breathing parameters, as discussed in greater detail below. For example, the electrical stimulation delivered to the lead 14 may be varied.

[0136] As used herein, the terms electrical stimulation, stimulation, stimulation pulse train, and so forth may refer to a single pulse or a train of pulses that operatively act as a single stimulation event. Parameters of the stimulation train which may be modified may include stimulation duration, magnitude of a stimulation current level, a frequency of stimulation, a periodicity of stimulation, a number of stimulation pulses, a pulse width of the stimulation pulses, a time during respiration that the stimulation is applied (for example, during hypopnea, hyperpnea, apnea, and so forth), and so forth. Based on the available data from the analysis of acquired information, therapy may be discontinued or extended, for example, to extend one breath or a number of breaths. The treatment system 10 may modify aspects of the electrical stimulation based at least in part on therapy-effectiveness information indicative of the efficacy and / or toleration of the therapy for the patient. Therapy-effectiveness information may include respiratory and / or non- respiratory information as discussed in further detail below. Further, the therapy-effectiveness information may be therapy-specific or patient-specific, as also discussed in further detail below. Additionally, therapy-effectiveness information may include information collected within a therapy window and / or information collected outside of a therapy window (or post-therapy information).

[0137] The therapy window is a pre-programmed time period during which stimulation to the target nerve may be applied. For example, a patient may generally sleep from 10 PM to 7 AM or from 10 AM to 6 PM. The IPG 12 for this patient would be pre-programmed (for example, by the external computing device 100) to provide disordered breathing therapy during a daily sleeping period, or therapy window, of 10 PM to 7 AM or 10 AM to 6 PM. During this therapy window, the IPG 12 may stop and start the delivery of electrical-stimulation to the target nerve depending on a state of arousal of the patient.

[0138] The post-therapy information may include, for example, respiratory information or non- respiratory information (for example, patient activity, patient position, heart rate, sleep stage, and so forth). Patient activity outside the therapy window may be higher with effective therapy than without because the patient will be more energetic and less lethargic. The post-therapy information may also include patient survey information regarding sleep quality, quality of daytime activity, and other indicators of improvements to the patient’s health due to a lack of disrupted sleep. In an example, the patient and / or clinician may provide post-therapy information to the system 10 and / or computing system 100 to effect modulation of therapy provision based on the post-therapy information in addition to therapy-effectiveness information, which may include information collected within a therapy window.

[0139] The therapy-effectiveness information may include therapy-specific indictors which may be indicators specific to the sleep-disordered breathing and / or the provision of sleep-disordered- breathing therapy. For example, if therapy- specific indicators show a persistence of sleep apnea symptoms during therapy stimulation, then the therapy stimulation may require an adjustment such as an increase in intensity in order to reduce or stop the sleep apnea events. The therapyspecific indicators may include respiratory and / or non-respiratory information. The one or more sensors 18 may provide the therapy-specific indicator data. These sensors may include a variety of external and / or implanted sensors as described herein which may include but are not limited to external and / or implanted flow sensor(s), external and / or implanted acoustic sensor(s), external and / or implanted vibration sensor(s), external and / or implanted electromyography (EMG) sensor(s), external and / or implanted heart rate sensor(s), external and / or implanted pressure sensor(s), external and / or implanted actigraphy sensor(s), external peripheral arterial tone sensor(s), external oxygen sensor(s), and / or external and / or implanted transthoracic impedance sensor(s).

[0140] The flow sensor(s) may be located in or externally near the upper airway of the patient, for example, in a nasal cannula. The acoustic sensor(s) may be microphone(s) located in or externally near the upper airway, on the chest of the patient, or in the thoracic cavity. The vibration sensor(s) may be accelerometer(s) and may be located in or externally near the upper airway. The EMG sensor(s) may be located in the upper airway region (for example, chin or glossal region) to sense stimulation of upper airway muscles, adhered to the neck or chin, and / or implanted on the diaphragm, or adhered to the abdomen of the patient near the diaphragm. The heart rate sensor(s) may be electrocardiogram (ECG) sensors, transthoracic impedance sensors, and / or pulse oximetry sensors. The actigraphy sensor(s) may be accelerometer(s) and / or other motion sensor(s) such as implanted accelerometers or accelerometers adhered to the patient and / or located on a belt or other garment or jewelry as a wearable device. The peripheral arterial tone sensor(s) and pulse oximetry sensor(s) may be external finger-worn devices, such as a clip or glove-tip sensor. The transthoracic impedance sensor(s) may be located on the chest of the patient as electrodes or may be implanted in the thoracic cavity. Sensors referred to as being located externally near the upper airway may be located for example on the head, for example, the chin, neck, or cervical region of the patient’ s body or may be inserted in the mouth or nose of the patient, for example, with an oral mouthpiece or a nasal cannula.

[0141] The therapy-effectiveness information may also include patient-specific indicators which may be indicators of poor sleep for the patient but which may or may not be specific to sleep- disordered breathing and / or the provision of sleep disordered breathing therapy. CSA, OSA, or other breathing disorders may produce poor sleep. Some examples of patient- specific indicators include, but are not limited to, patient movement, patient control input for therapy, patient sleep state, and patient position. For example, minimal or no sensed movement of a patient (such as wrist, chest, head, chin movement) may indicate an absence of sleep-disordered breathing and sensed movement may indicate occurrence of sleep-disordered breathing. Patient- specific indicators may include respiratory and / or non-respiratory information.

[0142] Patient control input may include conscious control via touch or voice feedback to a mobile device (for example, a smartphone) or a remote control to reduce or increase the intensity of therapy stimulation. Patient control input may also include conscious control via touch feedback to the implanted system 10, such as a tap on the chest above the implanted system 10 to reduce or increase the intensity of therapy stimulation. A lack of patient input via conscious control may indicate effective therapy. Changes in sleep state or duration of particular sleep states may indicate efficacy of therapy. Sensed parameters such as heart rate variability, EMG signals (for example, as measured by an implanted or external EMG sensor), peripheral arterial tone, and / or actigraphy signals (for example, as sensed by an implanted or external accelerometer) may indicate a sleep state such as light sleep, deep sleep, rapid eye movement, or awake. Further, patient position and / or roll frequency may indicate sleep state and / or sleep quality. For example, an upright patient is likely to be awake and a patient exhibiting high roll frequency may be experiencing discomfort from therapy and / or from sleep apnea.

[0143] These patient- specific indicators and changes in these patient-specific indicators may be due to sleep-disordered breathing and / or the provision of sleep-disordered breathing therapy but may also be independent of sleep disordered breathing and / or the provision of sleep-disordered- breathing therapy and due to unrelated causes. For example, a patient may move or change position or sleep state due to a stomachache or a nightmare or a need to urinate and such motion may be unrelated to sleep apnea and / or sleep apnea therapy. The system 10 may determine therapy-effectiveness information from physiological data received from one or more physiologic sensors (for example, physiological information sensed by the leads 14 and / or 16 and / or the sensors 18) and / or from patient-feedback information (for example, received by the computing device 100 from the patient 20, a physician, and so forth, as discussed below). The treatment system 10 may modify the electrical stimulation based directly on the physiological parameters and / or patient-feedback information, and / or may modify the electrical stimulation based on information determined from the physiological parameters and / or patient-feedback information. Information determined from the sensed physiological parameters and / or patientfeedback information may be used to determine a therapy-specific indicator indicative of an effect of the electrical stimulation on the respiration of the patient 20. One example of such a therapy- specific indicator may be a capture index, which may be a measure of therapy effectiveness for a particular patient 20. For example, the treatment system 10 may operate in a closed loop operation mode to automatically adjust the electrical stimulation based on the capture index.

[0144] In one example, IPG 12 may receive and process a signal representative of patient respiration to generate a histogram frequency distribution of patient breath lengths over a signal collection period, identify a stimulation frequency band (SFB) of sensed lengths in the histogram that is centered on a stimulation frequency, calculate a first sum of occupancies of breath lengths in a range of the stimulation frequency + / - a selected band width, calculate a second sum of occupancies of all of the lengths of sensed breaths (a respiratory frequency band [RFB]), and calculate the capture index as a ratio of the first sum over the second sum. In another example, the IPG 12 may determine the capture index based on a ratio of a variance of the SFB to a ratio of the total variance across the histogram. In yet a further example, the IPG 12 may determine the capture index by dividing the spectral power in an SFB by the spectral power in an RFB.

[0145] The SFB includes a range of frequencies at which electrical stimulation (or stimulation pulse train) is applied to the patient 20 by the treatment system 10. The RFB includes a range of frequencies at which the patient 20, or a human being in general, naturally respirates while asleep (for example, 0.5 - 1 Hz, 0.1 to 0.5 Hz, or another range). The capture index may represent the fraction of total spectral plot of respiration that falls into the SFB, and / or may implement a time-domain-based comparison of the relationship between the electrical stimulation and the breathing of the patient 20. For example, the time-domain-based comparison may include detecting a time between inhalation peaks over a certain period of time and determining, over that time, the number of breaths that are within a threshold of the programmed rate of treatment. In some examples, the value of capture index may increase proportionally with the entrainment of respiration by stimulation. The stimulation frequency thus becomes the dominant frequency of the respiration signal as entrainment increases.

[0146] As shown in FIG. 1A, in some examples, computing device 100 communicates with IPG 12 of treatment system 10 through a communication connection 30. In some examples, the communication connection 30 can be a wireless communication connection. For example, the wireless communication connection can be a telemetry communication connection and / or a Bluetooth® wireless communication connection between suitable circuitry in each of computing device 100 and the implanted (or implantable) pulse generator (IPG) 12 of treatment system 10. The treatment system 10 includes the IPG 12, one or more leads 14 and 16, and may include one or more sensors 18. As discussed below, the one or more sensors 18 may include implantable sensors and / or external sensors. In various examples, the computing device 100 may be an external device and at least a portion of the treatment system 10 may be implantable; accordingly, where the communication connection 30 is a wireless connection, the computing device 100 may communicate with the IPG 12 without removing the IPG 12 from the patient. External sensor may also communicate wirelessly with the IPG 12. A discussion of aspects of the treatment system 10 and the computing device 100, which is described with respect to FIG. 2, is provided in greater detail below.

[0147] In summary of one example of the foregoing, the IPG 12 may be implanted in the patient 20. The IPG 12 applies electrical stimulation to the patient 20 via the lead 14. In various examples, the electrical stimulation is provided to a target nerve of the patient 20 to stimulate the target nerve. For example, stimulating the phrenic nerve may cause the diaphragm of the patient 20 to contract. Thus, the treatment system 10 may influence breathing of the patient 20 by providing electrical stimulation via the lead 14. Influencing the breathing of the patient 20 may be performed to treat disordered breathing (for example, CSA, OSA, or other sleep disordered breathing). Treating the disordered breathing may include normalizing the breathing of the patient 20 or otherwise restoring the normal breathing of the patient 20. Feedback information, including sensed physiological parameters, patient-feedback information, information calculated based on sensed physiological parameters (for example, a therapy -specific indicator, such as a capture index), and so forth may be used to modify the treatment provided by the treatment system 10.

[0148] FIG. 3 illustrates a process 300 of operating the treatment system 10 according to an example. The process 300 may be executed by one or more controllers, such as the one or more controllers 50 within the IPG 12. As discussed above, the IPG 12 may be implanted in the patient 20. After implantation, in some examples the IPG 12 undergoes a calibration phase during which therapy is calibrated to the patient 20. The process 300 is described as beginning after the calibration phase. An example of the calibration phase is discussed below with respect to FIG. 5. The process 300 may begin once the treatment system detects that the patient 20 has fallen asleep or that sleep-indication conditions are satisfied, or has been asleep for at least a threshold period of time. In an implementation, the IPG 12 may perform the process 300 in an asynchronous mode of operation.

[0149] At act 302, the IPG 12 provides electrical stimulation to the patient 20. As discussed above, the IPG 12 may provide electrical stimulation via the lead 14, which may include or be coupled to electrodes, nerve cuffs, or other stimulation-delivery mechanisms. The electrical stimulation may be provided to a target nerve of the patient 20. The electrical stimulation may include a pulse train of stimulation.

[0150] At act 304, the IPG 12 determines breathing information for the patient 20. Breathing information may include breathing rate, lung volume, or other information indicative of the breathing of the patient 20. Breathing information may be determined based on information provided by the lead 16. For example, the lead 16 may include or be coupled to transthoracic- impedance sensors coupled to the patient 20. The transthoracic-impedance sensors may sense a change in impedance as the patient 20 breathes, which may be used by the IPG 12 to determine lung volume and / or breathing rate.

[0151] At act 306, the IPG 12 determines a capture index (CI) based on the breathing information. As discussed above, the CI may be determined by various methods (for example, histogram, variance, spectral density, and so forth). The CI may represent a degree to which the respiration of the patient 20 is synchronized with the stimulation provided by the treatment system 10. The CI is a ratio that may be represented by a number between 0 and 1, with higher values representing a higher degree of synchronization (and thus a higher degree of efficacy of treatment).

[0152] At act 308, the IPG 12 determines whether the CI is below a target threshold. The target threshold may be expressed as a number between 0 and 1, and may represent a minimum acceptable CI. The target threshold may, for example, be set by a physician for the patient 20 to ensure that a minimum acceptable level of treatment is being provided to the patient 20. One example target threshold might be 0.8. If the CI is at or above the target threshold (308 NO), and is therefore acceptable, the process 300 continues to act 310. At act 310, the IPG 12 maintains electrical- stimulation parameters at the current values. Electrical-stimulation parameters include parameters of the electrical stimulation provided at act 302, such as current magnitude, a number of pulses, a frequency of pulses, a pulse width, and so forth. Because the electrical stimulation may already be effective (as indicated by the CI being at or above the target threshold), the parameters may remain unchanged. The process 300 then returns to act 302 and repeats.

[0153] Returning to act 308, if the IPG 12 determines that the CI is below the target threshold (308 YES), then the process 300 continues to act 312.

[0154] At act 312, the IPG 12 determines whether one or more electrical- stimulation parameters are below one or more respective maximum values. The maximum values may correspond to a maximum intensity of the electrical stimulation. The one or more electrical-stimulation parameters considered at act 312 may include fewer than all of the parameters that the IPG 12 can modify in the electrical stimulation. The one or more electrical- stimulation parameters may include, for example, current magnitude. Certain patients may experience discomfort at higher- current stimulation. At high enough currents, patients may awaken from the electrical stimulation. Awakening patients may be disadvantageous because patient sleep is interrupted. Accordingly, the IPG 12 may modulate or adjust electrical-stimulation parameters in order to manage patient discomfort (for example, as subjectively felt by the patient 20). The IPG 12 may numerically increase some parameters and / or numerically decrease other parameters such that the intensity of the electrical stimulation is balanced with patient sensation. For example, a time delay between electrical stimulations may be numerically decreased while increasing the current of the electrical stimulation in order to increase intensity while reducing patient discomfort. If one or more first parameters are held at a particular value, a maximum value may be imposed on one or more second parameters such that patient discomfort is minimized or reduced. For example, if the time delay is held at a particular time delay value, a maximum current may be imposed with that particular time delay value.

[0155] If the IPG 12 determines that the one or more electrical-stimulation parameters are already at (or above) the maximum levels (312 NO), then the process 300 may continue to act 310. Although the CI is below the target threshold, increasing the electrical-stimulation parameters may be counterproductive inasmuch as, although the CI might increase, the patient 20 may also be awakened by the electrical stimulation. Accordingly, at act 310, the IPG 12 maintains the electrical- stimulation parameters rather than counterproductively increasing the electrical-stimulation parameters.

[0156] If the IPG 12 determines that the one or more electrical-stimulation parameters are below the one or more respective maximum values (312 YES), then the process 300 continues to act 314.

[0157] At act 314, the IPG 12 increases one or more electrical- stimulation parameters. The IPG 12 may modify fewer than all of the electrical-stimulation parameters that the IPG 12 is capable of controlling. For example, the IPG 12 may only increase a current magnitude of the electrical stimulation. The IPG 12 may increase the current magnitude in steps, such as 0.1 - 0.5 mA steps. The step size may depend on how low the present current magnitude is relative to a maximum current magnitude. If the present current magnitude is substantially lower than the maximum current magnitude, then the step size may be larger (for example, 0.5 mA). Conversely, if the present current magnitude is relatively close to the maximum current magnitude, then the step size may be smaller (for example, 0.1 mA). In various examples, parameters other than current magnitude may be adjusted in addition to, or in lieu of, the current magnitude. The process 300 then returns to act 302, whereby a new electrical stimulation is applied with the new parameters.

[0158] As discussed above, the patient 20 may experience a physical sensation when the electrical stimulation is applied at act 302. If the physical sensation is acute enough, the patient 20 may awaken in response to the electrical stimulation. This may be disadvantageous because the patient’s sleep is disturbed. Accordingly, treatment system 10 may be configured to monitor the patient 20 for signs indicating that the patient 20 is disturbed by the electrical stimulation. In some examples, movement of the patient 20 after electrical stimulation is applied is used to determine whether the patient 20 is disturbed by the electrical stimulation.

[0159] FIG. 4 illustrates a process 400 for determining whether to pause electrical stimulation to the patient 20 according to an example. The process 400 may be executed by one or more controllers, such as the one or more controllers 50 within the treatment system 10. The process 400 may be executed in parallel with the process 300.

[0160] At act 402, the IPG 12 applies electrical stimulation to the patient 20. Act 402 may be substantially similar or identical to act 302, and may refer to the same electrical stimulation. In some examples, the IPG 12 may already have information indicating a position that the patient 20 is in and apply electrical stimulation based on the position that the patient 20 is in. At act 404, the IPG 12 determines a position of the patient 20. The IPG 12 may determine the position of the patient using information received from one or more of the sensors 18. For example, the sensors 18 may include one or more accelerometers providing acceleration information indicative of movement of the patient 20. The accelerometers may be implanted in the patient 20 and / or may be external to the patient 20. For example, a three-axis accelerometer may be included in or disposed on the IPG 12 of treatment system 10 (see FIG. 1A). The IPG 12 may use the acceleration information to determine a position of the patient 20, such as a rightside position, a left-side position, a supine position, a prone position, and / or a vertical (for example, standing or sitting up) position. The acceleration information may indicate a position and / or movement of the patient 20 over a period of time, such as a period of time beginning shortly before the electrical stimulation is applied at act 402, and ending a brief time (for example, one to three seconds) afterwards. The period of time may be adjustable and may represent a period of time during which the patient 20 responds to the electrical stimulation.

[0161] At act 406, the IPG 12 determines whether the patient 20 is moving or changing positions (also referred to as rolling) in response to the electrical stimulation and / or is in a vertical position. The IPG 12 may determine whether the patient is rolling using the acceleration information. For example, if the IPG 12 determines that the patient 20 is in one position immediately before electrical stimulation, and rolls to another position after electrical stimulation, this may indicate that the patient 20 is disturbed by the electrical stimulation and rolling in response to the electrical stimulation. The IPG 12 may therefore determine that the patient is rolling based on determining that the patient 20 changes position within a period of time after electrical stimulation is applied, rolls at least a threshold number of degrees after electrical stimulation is applied, and so forth. This rolling may indicate that the electrical stimulation is too intense, and that the sleep of the patient 20 is likely to be, or already is, disturbed by the electrical stimulation. For example, the IPG 12 may correlate the rolling with another parameter, such as tidal volume, heart rate, respiration rate, and so forth, to increase a confidence that the rolling is caused by the electrical stimulation. Accordingly, if the IPG 12 determines that the patient 20 is rolling (406 YES), then the process 400 continues to act 408.

[0162] At act 408, the IPG 12 pauses stimulation of the patient 20. Pausing stimulation may include not applying any subsequent electrical stimulation for a period of time, such as 30 seconds, one minute, five minutes, or another period of time. In other examples, pausing stimulation may include not applying any subsequent electrical stimulation until the patient 20 is again identified as experiencing disordered breathing, or moves to a different position, or enters another stage of sleep, such as deep sleep, rapid-eye-movement (REM) sleep, and so forth. In still other examples, stimulation may be paused for a different period of time and / or until a different set of criteria is satisfied. Execution of the process 300 may be suspended while stimulation is paused. As discussed below, in some examples the IPG 12 may reduce the stimulation energy of the electrical stimulation rather than, or in addition to, pausing the stimulation of the patient 20 at act 408.

[0163] Returning to act 406, if the IPG 12 determines that the patient 20 is stationary (for example, not rolling or no longer rolling) (406 NO), then the process 400 returns to act 402. Electrical stimulation may continue to be applied to the patient 20. Because the patient 20 is not rolling in response to the electrical stimulation, the sleep of the patient 20 may be understood to not be disturbed by the electrical stimulation. Accordingly, the IPG 12 may continue to apply the electrical stimulation to the patient 20.

[0164] As discussed above, the patient 20 may undergo a calibration period prior to the IPG 12 being deployed (that is, fully prepared to be used to provide electrical stimulation to the patient 20 to treat a breathing disorder while the patient 20 sleeps). For example, the calibration period may be undergone prior to the processes 300, 400 being executed. The calibration period may be used to determine an acceptable range of electrical- stimulation parameters for the electrical stimulation applied to the patient 20. For example, the calibration period may be used to determine a maximum and / or minimum current magnitude of the electrical stimulation. The minimum current magnitude may be set to establish a starting current for electrical stimulation when therapy first begins (for example, when the patient 20 first falls asleep or when sleepindication conditions are satisfied). The minimum current magnitude may be set by determining a smallest current magnitude that provokes a response from the diaphragm.

[0165] The maximum current magnitude, and / or other electrical-stimulation parameters, may be set based on a subjective response of the patient 20 to electrical stimulation and may impose an upper limit for the current magnitude. For example, the patient 20 may self-report a description of how strongly felt the electrical stimulation is. If the electrical stimulation is too strong, then the maximum current magnitude may be reduced to minimize a likelihood of awakening the patient 20 in the future. In some examples, the intensity of the electrical stimulation is ramped up over the calibration period (for example, to build the tolerance of the patient 20 to the electrical stimulation) and the maximum values are selected once the electrical stimulation is fully ramped up to a target value.

[0166] FIG. 5 illustrates a process 500 of performing a calibration procedure according to an example. The process 500 may be performed after the IPG 12 is implanted in the patient 20, but prior to the IPG 12 being used to treat disordered breathing in the patient 20 outside of a controlled setting with a physician. The physician of the patient 20 may assist in performing the calibration procedure.

[0167] At act 502, the IPG 12 applies electrical stimulation to the patient 20. Act 502 may be similar to acts 302 and 402, albeit applied during the calibration period. The patient 20 may be awake at act 502 in some examples, and may be asleep at act 502 in other examples.

[0168] At act 504, the response of the patient 20 to the electrical stimulation is determined. In some examples, such as if the patient 20 is awake at act 502, act 504 includes the patient 20 providing patient-feedback information regarding the sensed intensity of the electrical stimulation. For example, the patient 20 may indicate that the electrical stimulation was too strong, or may indicate a ranking of how intense the electrical stimulation felt (for example, weak, medium, or strong). In other examples, sensed information may be used to determine the response of the patient 20 to the electrical stimulation, such as heart-rate information (for example, indicating a spike in heart rate responsive to the electrical stimulation), movement information (for example, indicating rolling while asleep in response to the electrical stimulation), and so forth. The sensed information may be used to determine how effective the treatment is, such as by measuring a response of the diaphragm of the patient 20 to the electrical stimulation. In some examples, the patient 20 provides the patient-feedback to the IPG 12, either directly or via the computing device 100. In other examples, the physician collects information indicative of the response of the patient 20 to the electrical stimulation.

[0169] At act 506, a determination is made as to whether calibration is complete. In some examples, the IPG 12 may execute act 506. For example, the IPG 12 may determine whether a threshold amount of time has passed since beginning calibration, or may determine that a threshold number of data points have been collected, or may determine that a set of calibrated parameters have been identified with at least a threshold confidence, and so forth. In other examples, the physician of the patient 20 may determine whether calibration is complete at act 506. The physician may determine that the calibration is complete based on, for example, determining that the breathing of the patient 20 is sufficiently entrained to the electrical stimulation provided to the patient 20. If calibration is complete (506 YES), the process 500 continues to act 508.

[0170] At act 508, minimum and / or maximum electrical stimulation parameter values are set. As discussed above at act 314, electrical-stimulation parameters may be modified to increase the efficacy of treatment provided by the IPG 12. The minimum and / or maximum values set at act 508 impose a range of values within which the parameters may be initially set and be subsequently modified at act 314, as discussed with respect to act 312. In some examples, the maximum values may be set by a physician. The physician may set the maximum value based on the physician’s evaluation of a maximum stimulation intensity that the patient 20 can comfortably receive without being awakened.

[0171] Returning to act 506, if calibration is not complete (506 NO), then the process 500 continues to act 510.

[0172] At act 510, a determination is made as to whether to change the electrical-stimulation parameters. During calibration, the electrical- stimulation parameters may be modified (for example, increased or decreased) based at least in part on the response of the patient 20 to the electrical stimulation. For example, if the patient 20 exhibits minimal response to an electrical stimulation, the intensity of the electrical stimulation may be increased to identify a maximum intensity that can be safely applied to the patient 20. Furthermore, as discussed above, the patient 20 may build tolerance to the electrical stimulation over the calibration period, and the intensity of the electrical stimulation may be increased as the tolerance of the patient 20 builds. In some examples, act 510 is performed by the physician. In other examples, act 510 is performed by the IPG 12 based, for example, on the response of the patient 20 to the previous electrical stimulation determined at act 504.

[0173] If the electrical-stimulation parameters are not changed (510 NO), then the process 500 returns to act 502. Otherwise, if the electrical- stimulation parameters are to be changed (510 YES), then the process 500 continues to act 512.

[0174] At act 512, the IPG 12 changes the electrical- stimulation parameters for subsequent electrical stimulation. The IPG 12 may change the electrical-stimulation parameters responsive to receiving input from the physician of the patient 20, for example. The physician of the patient 20 may modify the electrical- stimulation parameters throughout the calibration period to identify minimum and maximum electrical-stimulation parameters which are appropriate for the patient 20 until the calibration is complete at act 508. After modifying the electrical- stimulation parameters at act 512, the process 500 returns to act 502 for subsequent stimulation.

[0175] Accordingly, the processes 300-500 provide at least one example of implementing the IPG 12. After implantation of the IPG 12 in the patient 20, a calibration procedure (FIG. 5) is performed over a period of time (for example, several weeks or months) under supervision of a physician. Once the IPG 12 is ready to be deployed, the IPG 12 provides electrical stimulation to the patient 20 (FIG. 3). The electrical stimulation may be applied to the patient 20 after the patient 20 falls asleep or after sleep-indication conditions are satisfied in some examples; in other examples, the electrical stimulation may be provided to the patient 20 whether or not the patient 20 is asleep. If the electrical stimulation is not yielding a desired level of efficacy (for example, as indicated by a capture index), the intensity of the electrical stimulation may be increased. In conjunction with applying the electrical stimulation to the patient 20, the IPG 12 may monitor the patient 20 (FIG. 4) for signs that the intensity of the electrical stimulation is too high and is, or may soon, disturb the sleep of the patient 20, in which case the electrical stimulation is paused to avoid awakening the patient 20.

[0176] Although the processes 300-500 provide an example implementation of the treatment system 10 in which the treatment system 10 effectively provides treatment to the patient 20, the calibration period may be time-consuming and require professional oversight by a physician. Moreover, in some examples, while the intensity of the electrical stimulation may be increased responsive to determining that the efficacy of the treatment is below a target, the intensity of the electrical stimulation may not be decreased. Furthermore, the existence of a maximum threshold for the intensity of the electrical stimulation may give rise to a situation in which the intensity of electrical stimulation is not increased despite a determination that the efficacy of the treatment is below a target threshold. Finally, while the capture index provides a useful metric to evaluate therapy effectiveness, additional information might be available to provide a more complete picture of therapy effectiveness.

[0177] In other examples, the treatment system 10 may be implemented with additional or different automated capabilities. For example, the treatment system 10 may be deployed to provide stimulation to the patient 20 without a calibration period being performed, or with a shorter calibration period. Furthermore, while a shortened calibration may be implemented in some examples, minimum and / or maximum values may not be implemented. Rather, the treatment system 10 may modify the electrical- stimulation parameters freely based on therapy- effectiveness information indicative of the effects of previous stimulation.

[0178] FIG. 6 illustrates a process 600 of implementing the treatment system 10 according to an example. The process 600 may be executed by the IPG 12 after being implanted in the patient 20. The process 600 may be executed once the patient 20 is asleep or once sleep-indication conditions are satisfied, or has been asleep for at least a threshold period of time. For example, the lead 14 may be implanted in the vasculature of the patient 20 (for example, adjacent the phrenic nerve or the hypoglossal nerve, or may include a nerve cuff disposed around, and operatively coupled to, the target nerve of the patient 20). In one example, the lead 14 is implanted in the patient 20 to provide electrical stimulation to a phrenic nerve or hypoglossal nerve of the patient 20, and thereby treat disordered breathing in the patient 20. The lead 16 and / or sensors 18 may be coupled to, or otherwise be capable of sensing information indicative of, the patient 20.

[0179] At act 602, the IPG 12 applies electrical stimulation to the target nerve of the patient 20 via the lead 14. The electrical stimulation has, and / or is defined by, one or more electricalstimulation parameters (or stimulation parameters). The stimulation parameters include parameters such as a current magnitude of the electrical stimulation or of pulses making up the electrical stimulation, a duration of the electrical stimulation, a duration of the electrical stimulation relative to a length of a patient’s breathing cycle (which may include an inspiration period and an expiration period), a number of pulses of the electrical stimulation, a duty cycle of the pulses of the electrical stimulation, a frequency of the pulses of the electrical stimulation, a shape of each stimulation pulse, and so forth.

[0180] In some examples, the IPG 12 applies electrical stimulation to the patient 20 for each breathing cycle of the patient 20. A breathing cycle includes an inspiration period during which the patient 20 is (or should be) breathing in, and an expiration period during which the patient 20 is (or should be) breathing out. The breathing of the patient 20 may be entrained to the electrical stimulation. For example, the electrical stimulation may be applied to the patient 20 during or immediately after the inspiration period of the patient 20 for each breathing cycle such that the patient 20 is breathing in while the electrical stimulation is applied. In other examples, electrical stimulation may be delivered at a predetermined time and a predetermined respiratory rate, for example, as determined by a physician or determined by the IPG 12 based on the patient’s physiological parameter(s).

[0181] At act 604, the IPG 12 determines respiratory information. Respiratory information includes information indicative of at least one respiratory parameter of the patient 20. Respiratory parameters include parameters related to the breathing of the patient 20 and can be measured using at least one respiratory sensor of the sensors 18, such as: breathing-rate parameters (determined, for example, based on a transthoracic impedance measurement, pulse oximetry sensors, end tidal CO2 sensors, airway-pressure sensors, flow measurement sensors such as masks and / or cannulas, and so forth); lung-volume parameters (determined, for example, based on a transthoracic impedance measurement); blood-gas (for example, blood-oxygen) parameters (determined, for example, based on a pulse-oximeter, near-infrared spectroscopy sensors, and so forth); CO2 parameters (determined, for example, based on capnography based sensors); chest- and / or abdominal-motion parameters (determined, for example, based on accelerometer based sensors and / or other motion sensors); acoustic parameters indicative of patient-breathing sounds (determined, for example, based on an acoustic- sensor measurement); heart-rate-excursion parameters (determined, for example, based on an electrocardiogram measurement); and so forth. Respiratory parameters may be used to determine how effectively the patient 20 is breathing, and whether providing electrical stimulation to the patient 20 is effectively treating the disordered breathing of the patient 20. Respiratory parameters may be sensed via the sensors 18, the lead 14, the lead 16, a combination thereof, and so forth.

[0182] In one example, respiratory parameters include breathing-rate parameters indicative of a breathing rate of the patient 20. In one example, either or both of the leads 14, 16 include transthoracic-impedance sensors configured to determine a change in impedance caused by respiration of the patient 20. In various examples, as the patient 20 breathes and the chest of the patient 20 moves and changes shape, the transthoracic impedance may vary. Accordingly, transthoracic-impedance sensors may be used to determine a breathing rate of the patient 20 at least by detecting cyclical changes in transthoracic impedance.

[0183] In another example, respiratory parameters include blood-oxygen parameters indicative of a blood-oxygen level of the patient 20. For example, the sensors 18 may include a pulse oximeter to measure blood-oxygen parameters for the patient 20. In various examples, the pulse oximeter may be a finger- worn device or wrist- worn device to acquire blood-oxygen parameters for the patient 20 using an optical source and sensor. In various examples, the pulse oximeter may be referred to, or may be considered to be included in, an optical sensor. In some examples, the respiratory parameters may include both the breathing-rate parameters and the blood-oxygen parameters. In still other examples, the respiratory parameters may include parameters other than, or in addition to, breathing-rate and / or blood-oxygen parameters, such as end-tidal CO2, a shape or morphology of a breath waveform, a peripheral arterial tonometry signal, and so forth.

[0184] At act 606, the IPG 12 determines at least one therapy- specific indicator for the patient 20 based on the respiratory parameters. A therapy-specific indicator is a metric representing the effectiveness of therapy (that is, the electrical stimulation provided at act 602). The therapyspecific indicator may include, for example, a capture index, a peripheral oxygen saturation (SpO2), or another metric indicative of the effectiveness of the electrical stimulation. The therapy- specific indicator may be determined based on the respiratory parameters.

[0185] For example, a capture index may be determined based on breathing-rate parameters which might be acquired at act 604. As discussed above, in one example, the capture index may be determined by dividing the spectral power in the SFB by the spectral power in the RFB, which may be acquired at least in part by the transthoracic-impedance sensor.

[0186] In various examples, the SpO2 may be calculated based on the blood-oxygen parameters which might be acquired at act 604. For example, the SpO2 may be determined based on optical signals output by, and subsequently sensed by, a finger-worn pulse oximeter used by the patient 20. In some examples, act 606 may include determining multiple therapy-specific indicators, such as a capture index in addition to an SpO2 level. In still other examples, the therapy-specific indicator may include additional or different parameters.

[0187] At additional act 608, the IPG 12 may determine additional respiratory parameters and / or non-respiratory information as discussed below. Non-respiratory information includes information indicative of non-respiratory parameters, which may include parameters not directly indicative of the breathing of the patient 20. Non-respiratory parameters may include parameters such as patient-position parameters (determined, for example, based on an accelerometer measurement), heart-rate parameters (determined, for example, based on a heart-rate-sensor measurement), sleep-stage parameters (determined, for example, based on accelerometer measurements and / or heart-rate measurements), time-based parameters (determined based on various measurements and including, for example, an amount of time during which stimulation is applied, an amount of time during which a patient is in each position, an amount of time during which a patient is in each sleep stage, how often a patient moves, a number of times that a patient moves while asleep, and so forth), and so forth.

[0188] In some examples, the IPG 12 may be preprogrammed to execute additional act 608 (and, in turn, preprogrammed to determine specific types of additional therapy-effectiveness information), or may be preprogrammed to not execute additional act 608. For example, the IPG 12 may be preprogrammed to determine certain additional therapy-effectiveness information for one patient, but may be preprogrammed to determine different additional therapy-effectiveness information for a different patient. In some examples, a physician may select what, if any, additional therapy-effectiveness information the IPG 12 should determine at additional act 608 and program the IPG 12 accordingly. In some examples, therefore, whether additional act 608 is executed is preprogrammed into the IPG 12.

[0189] In various examples, however, the IPG 12 may dynamically determine whether and what additional therapy-effectiveness information to determine at act 608, for example, based on the at least therapy- specific indicator. For example, if the at least one therapy-specific indicator is within certain ranges of values (which may, for example, indicate that the effectiveness of therapy is unclear, and that additional information might be valuable), then the IPG 12 may dynamically determine that additional act 608 should be executed. In some examples, the IPG 12 may also dynamically determine what types of additional therapy-effectiveness information should be acquired at act 608.

[0190] An example of act 608 is discussed in greater detail below with respect to FIG. 7. Examples of what factors might determine whether to execute additional act 608, and how act 608 might be executed, are discussed with respect to FIGS. 9-11.

[0191] At additional act 610, the IPG 12 determines at least one patient-specific indicator. The at least one patient- specific indicator may be indicative of a condition of the patient 20. The condition of the patient may include, for example, whether the patient 20 enters a state of arousal in response to the electrical stimulation which might disturb the sleep of the patient 20. The IPG 12 may determine the at least one patient-specific indicator based at least in part on non- respiratory information acquired at act 608. For example, the at least one patient- specific indicator may be determined based on patient- feedback information provided by the patient 20, and / or may be determined based on sensed non-respiratory parameters such as a heart rate of the patient 20, movement of the patient 20, or other information not directly related to the breathing of the patient 20.

[0192] A sudden increase in heart rate of the patient 20, for example, may indicate that the condition of the patient 20 is aroused by the electrical stimulation. Similarly, a sudden movement by the patient 20 (for example, rolling to a new position) may indicate that the condition of the patient 20 is aroused by the electrical stimulation. In some examples, the at least one patientspecific indicator may be determined based on respiratory parameters in addition to, and / or in lieu of, the non-respiratory information.

[0193] At act 612, the IPG 12 determines whether to modify one or more electrical- stimulation parameters. The IPG 12 may determine whether to modify the one or more electrical- stimulation parameters based on the at least one therapy- specific indicator determined at act 606, the at least one patient- specific indicator, and / or based on the additional therapy-effectiveness information acquired at act 608. In various implementations, the IPG 12 may determine whether to modify the one or more electrical-stimulation parameters based on at least one therapy-specific indicator and at least one patient- specific indicator, or based on at least two therapy -specific indicators, or based on at least two patient- specific indicators. As shown for example in Tables 1, 2, and 3 below, combinations of parameters may provide more accuracy in identifying occurrences of sleep disordered breathing and confirming that therapy has resolved these occurrences as compared to using one parameter alone.

[0194] For example, if the at least one therapy-specific indicator includes a capture index with a value of 0.6, but a minimum threshold of effectiveness includes a capture index of 0.8, then the IPG 12 may determine that the electrical stimulation should be increased in intensity. In another example, if the at least one patient- specific indicator includes movement parameters indicating that the patient 20 rolled over immediately after the electrical stimulation applied at act 602, then the IPG 12 may determine that the electrical stimulation should be reduced in intensity.

[0195] As discussed above, the one or more electrical-stimulation parameters include parameters characterizing the electrical stimulation, such as current magnitude, pulse width, and so forth. An intensity of the electrical stimulation may be increased (for example, by increasing a current magnitude or decreasing a time between pulses) or decreased (for example, by decreasing a current magnitude or increasing a time between pulses) by modifying electrical- stimulation parameters at act 612. Increasing the intensity of the electrical stimulation may have the potentially advantageous effect of increasing the diaphragm’ s response to the electrical stimulation, such as by contracting more or more quickly. However, increasing the intensity of the electrical stimulation may also increase the patient’s (20) discomfort with the electrical stimulation, which may have the potentially disadvantageous effect of disturbing the sleep of the patient 20 (or, if the patient 20 is awake while the electrical stimulation is applied, disturbing the patient 20 in general).

[0196] As discussed in greater detail below, act 612 may include the IPG 12 weighing the at least one therapy-specific indicator against the at least one patient- specific indicator. The at least one therapy- specific indicator may indicate how effectively therapy is being provided and may suggest that the intensity of the electrical stimulation should be increased if the therapy is not effective. The at least one patient- specific indicator may indicate how much, if any, discomfort the patient 20 is experiencing in response to the electrical stimulation, and may suggest that the intensity of the electrical stimulation should be decreased if the sleep of the patient 20 is being disturbed. Examples are discussed below.

[0197] If the IPG 12 determines that the electrical-stimulation parameters should not be modified (612 NO), then the process 600 continues to act 614. At act 614, the IPG 12 maintains the electrical-stimulation parameters at present values and returns to act 602 to apply a subsequent electrical stimulation with the same electrical-stimulation parameters. Accordingly, act 614 may include taking no action.

[0198] Conversely, if the IPG 12 determines that the electrical-stimulation parameters should be modified (612 YES), then the process 600 continues to act 616. At act 616, the IPG 12 modifies one or more of the electrical-stimulation parameters. For example, if the IPG 12 determines that the capture index is below a threshold value (indicating that the treatment may not be sufficiently effective) and that the patient 20 is not aroused by the electrical stimulation (indicating that the treatment is not too intense), then the IPG 12 may increase the intensity of the electrical stimulation, such as by increasing a current magnitude. The process 600 then returns to act 602, whereby a subsequent electrical stimulation is applied with the modified electrical-stimulation parameters.

[0199] Accordingly, the process 600 may be executed to provide electrical stimulation to the patient 20 to treat disordered breathing in the patient 20. The IPG 12 may automatically adjust the electrical stimulation over time based on various information, such as respiratory parameters and / or non-respiratory information. For example, the IPG 12 may operate in a closed loop operation mode to automatically adjust the electrical stimulation based on physiological feedback from one or more sensors (for example, the one or more sensors 18), which may include therapy- specific indicator(s) and / or patient- specific indicator(s). Using the respiratory parameters and / or non-respiratory information, the IPG 12 may determine at least one therapy- specific indicator indicative of an effectiveness of therapy, and / or at least one patient- specific indicator indicative of the condition of the patient 20. The IPG 12 may increase, decrease, or maintain the intensity of the electrical stimulation based on the at least one therapy- specific indicator and / or the at least one patient-specific indicator.

[0200] For example, the IPG 12 may increase the intensity if the at least one therapy- specific indicator and / or at least one patient-specific indicator are within certain respective ranges of values, or may decrease the intensity if the at least one therapy- specific indicator and / or at least one patient- specific indicator are within certain other respective ranges of values. The particular methodology of determining whether to modify the electrical-stimulation parameters may depend at least in part on what, if any, additional therapy-effectiveness information is acquired at act 608. One example of act 608 is therefore provided with respect to FIG. 7.

[0201] In some examples, the process 600 is executed once per breathing cycle of the patient 20. For example, the IPG 12 may execute act 602 to apply electrical stimulation to the patient 20 during each inspiration period of the patient 20. In some iterations of the process 600, fewer than all of the acts may be executed. For example, in some examples act 602 may be executed for ever)' breathing cycle of the patient 20, whereas acts 604-616 may only be executed every other breathing cycle, every fifth breathing cycle, every minute, or some other period of time. Moreover, the order of acts of the process 600 are provided only for purposes of one example. In some examples, the acts of the process 600 may be executed in a different order, either consistently (that is, consistently executed in an order not illustrated in FIG. 6) or varyingly (that is, executed in one order during one iteration, but executed in a different order during a subsequent iteration).

[0202] In other examples, the process 600 is executed to deliver an electrical stimulation periodically. The electrical stimulation may include multiple pulses. The duration and period of the stimulation may be predetermined and pre-programmed at the IPG 12, for example by a physician, or may be determined by the IPG 12 based on the patient’s 20 physiological (for example, respiratory) parameters and / or patient-feedback information.

[0203] Tables 1, 2, and 3 below show further examples of therapy-specific indicator data characteristics in the presence of sleep disordered breathing (SDB) as measurable with various sensors. In the example of FIG. 6, one or more of these parameters may be determined, for example, at the acts 606 or 608. The therapy- specific indicator data may correspond to a particular physical condition of the patient such as low airflow resulting in oxygen desaturation, a closed or partially obstructed airway (which may correspond to a decrease in airway patency), or insufficient diaphragm contractions.

[0204] These therapy- specific indicators may be relevant to CSA, OSA, or both as shown in Tables 1, 2, and 3. For each therapy- specific indicator, Tables 1, 2, and 3 indicate a signal characteristic for the sensor and the therapy- specific indicator in the presence of sleep disordered breathing. Each of these signal characteristics is a characteristic relative to an expected signal for a normal patient (where a normal patient is a patient with ordered breathing that is not experiencing sleep apnea or other SDB). The expected signal may be a baseline signal for a particular patient or may be an expected signal over a patient population. Thus, if the applied therapy has restored ordered breathing, then these signals will revert back to the expected signal for the normal patient. For example, with an obstructed airway, flow is zero or low but if the therapy results in an unobstructed airway, flow will return to a normal, non-zero value.

[0205] In various implementations, the IPG 12 may determine whether to modify one or more stimulation parameters at the act 612 based on these characteristics. For example, where the type of sensor data indicates or confirms a physical condition associated with SDB, the IPG 12 may modify one or more stimulation parameters at the act 616. For example, the IPG 12 may modify one or more stimulation parameters to increase the intensity of the provided stimulation in order to resolve the SDB.

[0206] Conversely, where the type of sensor indicates or confirms an absence of the physical condition associated with SDB, the IPG 12 may maintain the electrical stimulation parameters at the act 614. For example, according to row A of Tables 1, 2, and 3 where the IPG 12 determines that flow sensor data indicates low flow, acoustic sensor data indicates high noise, vibration sensor data indicates variable or low vibration, transthoracic impedance sensor data indicates variable transthoracic impedance, heart rate sensor data indicates a variable heart rate, peripheral arterial tone sensor data indicates variable arterial tone, EMG sensor data indicates variable or low EMG signals, and / or chest and diaphragm motion data indicates a variable phase relationship, the IPG 12 may modify the electrical stimulation parameters to increase the stimulation energy provided to one or more of the phrenic nerve or the hypoglossal nerve. Similarly, the IPG 12 may modify the electrical stimulation parameters to increase the stimulation energy provided to the hypoglossal nerve based on the sensor data characteristics indicated in row B of Tables 1, 2, and 3. Similarly, the IPG 12 may modify the electrical stimulation parameters to increase the stimulation energy provided to the hypoglossal nerve based on the sensor data characteristics indicated in row C of Tables 1, 2, and 3.

[0207] Descriptors of “low” or “high” indicate that a discrete measurement or an average over time is lower than the expected signal. Descriptors of “no signal” indicate a reading of zero or an absence of a detected signal. For example, if an airway is completely obstructed, an airflow signal will measure zero flow. Descriptors of “variable” indicate that the detected signal shows more variability and / or disorder than the expected signal for the normal patient. Disorder may apply where a signal deviates from an organized repetitive variation. For example, air flow, transthoracic impedance and diaphragm motion signals are generally sinusoidal for a normal patient and exhibit disorder in the presence of SDB. Pulse oximetry, peripheral arterial tone, and heart rate are examples of discrete value indicators that are approximately constant over time in a normal patient.

[0208]

[0209] FIG. 7 illustrates a process 700 of determining additional therapy-effectiveness information according to an example. The process 700 may illustrate one example of act 608. As discussed below, the additional therapy-effectiveness information broadly includes patientfeedback information (that is, information directly provided by the patient 20) and additional sensed parameters (that is, parameters sensed by the sensors 18 and / or the leads 14, 16), whether the additional sensed parameters be respiratory parameters or non-respiratory information.

[0210] In some examples, the process 700 may be intended to explain an example of act 608 and may not represent actual affirmative acts executed by any particular entity, such as the IPG 12. For example, the IPG 12 may be preprogrammed to determine (or not determine) certain additional therapy-effectiveness information prior to executing the process 600. Thus, the process 700 may be provided strictly for purposes of explanation, and may not represent affirmative acts performed by a particular entity. In other examples, the IPG 12 may affirmatively execute acts of the process 700. At act 702, a determination is made as to whether to obtain patient-feedback information. For example, act 702 may include determining whether the IPG 12 is preprogrammed to receive and / or solicit feedback from the patient 20. Alternatively, act 702 may include determining whether patient- feedback information has been received from the patient 20. Patient-feedback information may be a form of non-respiratory information. The patient-feedback may be indicative of the subjective perception of the patient 20 to the intensity of the electrical stimulation. For example, if the electrical stimulation is too intense and is awakening the patient 20, the patient 20 may request that the intensity be decreased (or may directly decrease the intensity). As noted above, act 702 may not be affirmatively executed by any particular entity, and may be provided for purposes of explanation only, though in some examples act 702 may be executed by the IPG 12, such as by the IPG 12 determining whether patient-feedback information has been received and is available. Accordingly, if the IPG 12 is configured to obtain patient-feedback information (702 YES), then the process 700 continues to act 704.

[0211] At act 704, the IPG 12 obtains patient-feedback information. The patient 20 may provide patient-feedback information via the computing device 100. For example, the patient 20 may provide patient-feedback information via the input device 114 and / or the display 116, which may be a touch-sensitive display. Providing the patient-feedback information may include the patient 20 manually decreasing the intensity of the electrical stimulation. In another examples, providing the patient- feedback information may include the patient 20 indicating how intense the electrical stimulation feels (for example, weak, average, or strong), and the IPG 12 may use this patientfeedback information (which may be a form of non-respiratory information) in determining whether to modify the electrical- stimulation parameters at act 612.

[0212] Otherwise, if the IPG 12 is not configured to receive patient-feedback information or if patient-feedback information is not being received or solicited at this particular time (702 NO), then the process 700 continues to act 706.

[0213] At act 706, a determination is made as to whether to obtain additional sensed non- respiratory parameters and / or sensed respiratory parameters (collectively, additional sensed parameters). Whereas the patient-feedback information may be provided directly by the patient 20 (for example, via a user interface of the computing device 100), the additional sensed parameters may be sensed by at least one of the sensors 18, where one or both of the leads 14, 16 may include one or more of the sensors 18. Act 706 may include determining whether to poll the sensors 18 and / or leads 14, 16 for sensed parameters. In some examples, act 706 is provided for purposes of example and is not affirmatively executed by any particular entity. For example, the IPG 12 may be preprogrammed to obtain certain additional sensed parameters for the patient 20. In various examples, the IPG 12 may execute the act 706. For example, the IPG 12 may determine whether to obtain additional sensed parameters based on certain conditions being met, such as a time having elapsed since additional sensed parameters was previously obtained or the at least one therapy-specific indicator indicating that additional parameters may be useful. If the IPG 12 determines that additional sensed parameters should be obtained (706 YES), then the process 700 continues to act 708.

[0214] At act 708, the IPG 12 obtains additional sensed parameters. In some examples, the IPG 12 obtains additional respiratory parameters, such as breathing rate, blood-gas parameters, lung volume, acoustic parameters indicative of snoring, and so forth. In various examples, the IPG 12 obtains additional sensed non-respiratory parameters, such as heart-rate parameters, movement parameters indicative of the patient 20 rolling, and so forth. The non-respiratory information, which may include the patient- feedback information obtained at act 704 and / or the sensed non- respiratory parameters obtained at act 708, may be subsequently used to determine the at least one patient- specific indicator at act 610. Examples of additional sensed parameters are provided with respect to FIGS. 8A-8C.

[0215] After act 708, or if no additional sensed parameters are to be obtained (706 NO), the process 700 ends. For examples in which the process 700 is an example of act 608, this may include continuing to act 610 in the process 600.

[0216] Accordingly, when the IPG 12 executes the process 600, the IPG 12 provides electrical stimulation to the patient 20 (act 602) while repeatedly determining whether to modify one or more electrical-stimulation parameters of the electrical stimulation (act 612). The IPG 12 may determine whether to modify the one or more electrical-stimulation parameters at least based on the therapy-specific indicator (act 606). In addition, the IPG 12 may determine additional therapy-effectiveness information (act 608) which may also be used to determine whether to modify the one or more electrical-stimulation parameters.

[0217] In various examples, the IPG 12 may be preprogrammed to acquire certain additional therapy-effectiveness information (act 608, an example of which may include acts 702-708). The therapy-effectiveness information may include patient-feedback information provided directly by the patient 20 (act 704), and / or may include additional sensed parameters sensed by the sensors 18 and / or the leads 14, 16 (act 708). The therapy-effectiveness information may be used to determine at least one patient-specific indicator (act 610). The IPG 12 may use the therapyeffectiveness information and / or the at least one patient- specific indicator, in addition to the at least one therapy-specific indicator, to determine whether to modify the electrical- stimulation parameters (act 612). Accordingly, the IPG 12 may provide electrical stimulation to the patient 20 while repeatedly, dynamically determining whether to modify the electrical-stimulation parameters.

[0218] An example of determining additional sensed parameters at act 708 is provided with respect to FIGS. 8A-8C. FIGS. 8-8C illustrate acts of determining whether to determine various types of sensed parameters. In various examples, these acts may not be affirmatively executed by any particular entity and are provided for purposes of explanation only, although certain entities may affirmatively execute the acts of actually determining the sensed parameters (such as the IPG 12, alone or in combination with the sensors 18 and / or leads 14, 16).

[0219] FIGS. 8A-8C illustrate a process 800 for determining additional sensed parameters according to an example. The process 800 may be an example of act 708. In some examples, certain acts of the process 800 (for example, decision blocks illustrated as diamonds) may not be executed by any particular entity and may be illustrated for purposes of explanation, and other acts of the process 800 (for example, action blocks illustrated as rectangles) may be executed by the IPG 12 (alone or in combination with the sensors 18 and / or leads 14, 16). In other examples, all acts of the process 800 may be executed. For example, in executing the decision blocks illustrated as diamonds, the IPG 12 may determine whether to obtain certain parameters based on one or more criteria, such as whether a threshold period of time has elapsed since previously acquiring that type of parameters.

[0220] At act 802, a determination is made as to whether to acquire breathing-rate parameters. Breathing-rate parameters may be an example of respiratory parameters or information. Breathing-rate parameters may include parameters indicative of a rate at which the patient 20 is breathing. In general, regular breathing rhythms entrained to the electrical stimulation may indicate that the patient 20 is breathing normally, whereas irregular breathing may indicate that the patient 20 is not breathing normally. Accordingly, the breathing rate (or a value derived therefrom, such as capture index) may be used as a therapy- specific indicator to evaluate the effectiveness of therapy. If breathing-rate parameters is to be acquired (802 YES), the process 800 continues to act 804.

[0221] At act 804, the IPG 12 obtains breathing-rate parameters indicative of a breathing rate of the patient 20. The IPG 12 may determine the breathing-rate parameters based on parameters received from the sensors 18 and / or the leads 14, 16.

[0222] In a first example, one or both of the leads 14, 16 may include transthoracic-impedance sensors coupled across the chest of the patient 20. As the patient 20 breathes, the impedance between the transthoracic impedance sensors may vary. The IPG 12 may receive this impedance parameters and determine a breathing rate of the patient 20 based on the cyclical variations in impedance. The IPG 12 may obtain or determine a waveform indicative of the breathing pattern of the patient 20 from the impedance parameters.

[0223] In a second example, the sensors 18 may include one or more acoustic sensors. The acoustic sensors may sense acoustic parameters, which may include sounds produced when the patient 20 breathes in and out. The IPG 12 may receive these acoustic parameters and determine a breathing rate of the patient 20 based on the sounds produced by the patient 20 breathing. For example, the sounds produced by the patient 20 may generally oscillate over time, and the IPG 12 may determine a breathing rate of the patient 20 based on the cyclical variations in the sounds. The IPG 12 may obtain or determine a waveform indicative of the breathing pattern of the patient 20 from the sounds.

[0224] In a third example, the sensors 18 may include one or more accelerometers. The accelerometers may sense acceleration parameters indicative of movement, which may include movement of the chest (for example, if the patient 20 is a chest-breather) or movement of the abdomen (for example, if the patient 20 is an abdomen-breather) of the patient 20 as the patient 20 breathes in and out. For example, an accelerometer may be coupled to the chest or abdomen of the patient 20. The IPG 12 may receive this movement parameters and determine a breathing rate of the patient 20 based on the cyclical variations in movement caused by the motion of the chest or abdomen of the patient 20.

[0225] In a fourth example, the sensors 18 may include one or more pressure sensors. The pressure sensors may sense pressure parameters, which may include changes in pressure in or on the chest of the patient 20 as the patient 20 breathes in and out. For example, a pressure sensor may be externally disposed on the patient 20, may be disposed in a device configured to interface with the airway of the patient, or be implanted in the chest of the patient 20. As the patient 20 breathes, the change in shape and / or volume of the lungs and / or diaphragm, and / or the resulting changes respiratory rate, volume, and so forth, may result in a variable pressure being exerted on the pressure sensor. The IPG 12 may receive these pressure parameters and determine a breathing rate of the patient 20 based on the cyclical variations in pressure caused by the motion of the chest of the patient 20.

[0226] In other examples, the breathing-rate parameters may include additional and / or different types of parameters. The breathing-rate parameters may include multiple types of parameters from the foregoing examples, in addition to or in lieu of additional parameters. The process 800 continues to act 806 upon obtaining the breathing-rate parameters, or if no breathing-rate parameters is to be determined (802 NO).

[0227] At act 806, a determination is made as to whether to determine blood-gas parameters, for example blood-oxygen parameters, indicative of a blood-oxygen level of the patient 20. Blood- oxygen parameters may be an example of respiratory parameters or information. Blood-oxygen parameters may include parameters indicative of a level of oxygen in the blood of the patient 20, such as parameters that might be used to determine an SpO2 level. In some examples, a higher SpO2 reading may indicate that the patient 20 is breathing normally, and a lower SpO2 reading may indicate that the patient 20 is not breathing normally. In various examples, regardless of the specific value of the SpO2 reading, an SpO2 reading that remains relatively constant over time may indicate that the patient 20 is breathing normally, whereas a highly variable, erratic SpO2 reading may indicate that the patient 20 is not breathing normally. Accordingly, the SpO2 reading may be used as a therapy-specific indicator to determine the effectiveness of therapy and whether to modify the one or more electrical- stimulation parameters. For example, if the SpO2 reading is below a threshold SpO2 level (for example, 95%) and / or the SpO2 reading varies substantially over time (for example, by more than 2% over one minute), the IPG 12 may determine that the electrical stimulation should be intensified. In some examples, blood-oxygen parameters may additionally or alternatively include parameters indicative of oxygenation of body tissues, such as brain tissue, muscle tissue, and / or cardiac tissue. If blood-oxygen parameters are to be obtained (806 YES), the process 800 continues to act 808.

[0228] At act 808, the IPG 12 obtains blood-oxygen parameters for the patient 20. The IPG 12 may determine the blood-oxygen parameters based on parameters received from the sensors 18. In one example, the sensors 18 include a pulse oximeter. A pulse oximeter may include a finger- worn device equipped with an optical source and an optical sensor. Light is applied by the optical source to the finger of the patient 20 and subsequently sensed by the optical sensor. The pulse oximeter may output blood-oxygen parameters encoding the properties of the sensed light. The IPG 12 may use the blood-oxygen parameters to determine an SpO2 reading. As discussed above, the SpO2 reading may be used to evaluate the effectiveness of therapy provided by the IPG 12.

[0229] In other examples, the blood-oxygen parameters may include additional and / or different types of parameters. For example, as discussed above, the blood-oxygen parameters may additionally or alternatively include parameters indicative of oxygenation of body tissues. The sensors 18 may include an optical sensor such as a near- infrared spectroscopy sensor to detect tissue oxygenation (for example, in a target tissue such as myocardial muscle tissue, brain tissue, and so forth). The process 800 continues to act 810 upon obtaining the blood-oxygen parameters, or if no blood-oxygen parameters is to be determined (806 NO).

[0230] At act 810, a determination is made as to whether to determine a position of the patient 20. The position of the patient 20 may be an example of a non-respiratory parameter or information. In some examples, the position of the patient 20 may include a left-side sleeping position, a right-side sleeping position, a supine sleeping position, or a prone sleeping position. Determining the position of the patient 20 may additionally or alternatively include determining movement of the patient 20 (that is, a change in position of the patient 20) over a period of time, such as within several seconds after electrical stimulation is applied. In some examples, movement of the patient in response to electrical stimulation may indicate that the patient 20 is disturbed by the electrical stimulation.

[0231] In a different context, a position of the patient 20 may affect how treatment is provided to the patient 20. For example, the patient 20 may have no difficulty breathing in a prone position, but may experience disordered breathing in a supine position.

[0232] In still other examples, determining the position of the patient 20 may include determining the position of the torso of the patient 20 relative to the head of the patient 20, because an angle between the torso and head of the patient 20 may affect a shape of the airway of the patient 20 and thus affect the breathing of the patient 20. Accordingly, the position of the patient 20 may be used to determine whether and what kind of therapy to provide to the patient 20. If the position of the patient 20 is to be determined (810 YES), then the process 800 continues to act 812.

[0233] At act 812, the IPG 12 obtains position parameters indicative of a position of the patient 20. The IPG 12 may determine the position parameters based on parameters received from the sensors 18. In one example, the sensors 18 include at least one accelerometer. The accelerometer may be coupled to the patient 20 such that when the patient 20 moves, the accelerometer senses the movement of the patient 20. In some examples, the sensors 18 include multiple accelerometers, such as a first accelerometer coupled to the chest of the patient 20 and a second accelerometer coupled to the head of the patient 20. Accelerometers may be external to the patient 20 and / or implanted within the patient 20 (for example, in the IPG 12). As discussed above, position parameters may be useful in at least three examples.

[0234] In a first example, the position parameters may be used to identify movement of the patient 20, such as rolling. If the patient 20 rolls in response to electrical stimulation being applied, this may be indicative of the sleep of the patient 20 being disturbed by the electrical stimulation. The IPG 12 may detect this rolling by determining whether the position parameters indicate that, within a certain range of time after applying electrical stimulation, the patient 20 changed sleeping positions. The IPG 12 may therefore modify one or more electrical-stimulation parameters of the electrical stimulation to reduce the intensity of the electrical stimulation based on the movement parameters.

[0235] In a second example, the position parameters may be used to determine a position that the patient 20 is currently in. The IPG 12 may apply different treatment regimens to the patient 20 for different sleeping positions. For example, if the patient 20 does not experience disordered breathing in a right-side position, then the IPG 12 may pause stimulation when the patient 20 is in the right-side position. If the patient 20 experiences mild disordered breathing in a supine position, then the IPG 12 may apply electrical stimulation to the patient 20 with one or more electrical-stimulation parameters corresponding to a relatively mild electrical stimulation to the patient 20 while the patient 20 is in the supine position. If the patient 20 experiences significant disordered breathing in a left-side position, then the IPG 12 may apply electrical stimulation to the patient 20 with one or more electrical-stimulation parameters corresponding to a relatively intense electrical stimulation to the patient 20 while the patient 20 is in the left-side position. In a third example, the position parameters may be used to determine a relative position between the head of the patient 20 and the torso of the patient 20. The IPG 12 may apply different treatment regimens to the patient 20 for different relative head-and-torso positions. For example, if the patient 20 does not experience disordered breathing when the head of the patient 20 is aligned with the torso of the patient 20 (that is, as though the patient 20 were looking straight ahead), then the IPG 12 may pause stimulation when the head of the patient 20 is aligned with the torso of the patient 20. Conversely, if the patient 20 experiences disordered breathing when the head of the patient 20 is not aligned with the torso of the patient 20 (for example, as though the patient 20 were looking to the left or right), then the IPG 12 may apply electrical stimulation to the patient 20 while the head of the patient 20 is not aligned with the torso of the patient 20.

[0236] In other examples, the position parameters may be used in additional or different ways. The position parameters may include multiple types of parameters from the foregoing examples, in addition to or in lieu of additional parameters. The process 800 continues to act 814 upon obtaining the position parameters, or if no position parameters is to be determined (810 NO).

[0237] At act 814, a determination is made as to whether to determine chest- motion parameters indicative of movement of the chest of the patient 20. In some examples, act 814 may further or alternatively include determining parameters indicative of movement of the abdomen of the patient 20. The chest- and / or abdomen-motion parameters may be an example of respiratory parameters or information. The chest- and / or abdomen-motion parameters may be indicative of movement of the chest and / or abdomen of the patient 20 relative to the torso of the patient 20, that is, movement caused by the patient 20 breathing rather than sitting up or rolling over. In some examples, as discussed above with respect to act 804, determining the breathing-rate parameters may include analyzing movement of the chest and / or abdomen of the patient 20. In some examples, chest- and / or abdomen-motion parameters may be separately used to determine parameters in addition to, or in lieu of, breathing-rate parameters as discussed below. If chest- and / or abdomen-motion parameters are to be determined (814 YES), then the process 800 continues to act 816.

[0238] For purposes of brevity, act 816 is described with respect to chest-motion parameters; however, in various examples act 816 may additionally or alternatively include determining abdomen-motion parameters in a substantially similar manner, except with accelerometers coupled to an abdomen of the patient 20 rather than the chest of the patient 20. For example, whereas chest-motion parameters may be determined for chest-breathing patients using at least one accelerometer coupled to the chest of the patient, abdomen-motion parameters may be determined for abdomen-breathing patient using at least one accelerometer coupled to the abdomen of the patient.

[0239] At act 816, the IPG 12 determines chest- motion parameters indicative of movement of the chest of the patient 20. The IPG 12 may determine the position parameters based on parameters received from the sensors 18. In one example, the sensors 18 include at least one accelerometer. A first accelerometer may be coupled to the chest of the patient 20 such that the first accelerometer moves when the patient 20 breathes in and out. A second accelerometer may be coupled to the patient 20 at a location that does not move when the patient 20 breathes in and out, such that relative motion between the first and second accelerometer may be used to isolate motion caused by the patient 20 breathing from motion caused by the patient 20 rolling, sitting up, and so forth. Accordingly, the IPG 12 may use the chest-motion parameters to determine how the chest of the patient 20 is moving relative to the torso of the patient 20.

[0240] As discussed above, chest-motion parameters may be used to determine a breathing rate of the patient 20. Chest-motion parameters may also be used to determine additional parameters, such as a speed and / or acceleration of the chest of the patient 20. If the chest of the patient 20 suddenly accelerates very quickly (that is, if the IPG 12 determines that the chest of the patient 20 accelerates above a threshold acceleration), the patient 20 may be gasping, which may indicate that the breathing of the patient 20 is disturbed. Accordingly, while parameters indicative of motion of the chest of the patient 20 may be used to determine breathing-rate parameters as discussed above with respect to act 804, the chest-motion parameters may additionally or alternatively be used to determine other aspects of the breathing of the patient 20, such as whether the patient 20 is gasping. The process 800 continues to act 818 upon obtaining the chest-motion parameters, or if no chest-motion parameters is to be determined (814 NO).

[0241] At act 818, a determination is made as to whether to acquire heart-rate parameters for the patient 20. The heart-rate parameters may be an example of non-respiratory parameters or information. Heart-rate parameters may indicate a number of beats-per-minute of the heart of the patient 20. Heart-rate parameters may be used to determine, for example, whether the patient 20 is aroused by electrical stimulation. For example, if the heart rate of the patient 20 suddenly increases immediately after applying electrical stimulation, the IPG 12 may determine that the patient 20 is being aroused and potentially awakened by the electrical stimulation. Similarly, if the heart rate of the patient 20 changes erratically throughout the night, the IPG 12 may determine that the patient 20 is not experiencing undisturbed sleep. If heart-rate parameters are to be determined (818 YES), then the process 800 continues to act 820.

[0242] At act 820, the IPG 12 determines heart-rate parameters for the patient 20. The IPG 12 may determine the heart-rate parameters based on parameters received from the sensors 18 and / or the leads 14, 16. In one example, the sensors 18 include an electrical-activity sensor to sense electrical activity of the heart. In another example, the sensors 18 include an optical source and sensor to detect expansion and contraction of the arteries of the patient 20 caused by the heart pumping blood. In another example, the sensors 18 may include an acoustic sensor to detect sounds or other acoustic vibrations created by the heart pumping blood (for example, heart sounds). In another example, one or both of the leads 14, 16 may include or be coupled to electrodes configured to detect electrical activity of the heart of the patient 20. In other examples, other sensors may be implemented to determine the heart rate of the patient 20. The IPG 12 may receive these parameters to determine a heart rate of the patient 20 and modify therapy based on the heart-rate parameters. The process 800 continues to act 822 upon obtaining the heart-rate parameters, or if no heart-rate parameters is to be determined (818 NO).

[0243] At act 822, a determination is made as to whether to determine sleep-stage information for the patient 20. Sleep-stage information may be an example of respiratory or non-respiratory information. Sleep-stage information may include information indicative of a sleep stage of the patient 20, such as light sleep, deep sleep, and REM sleep. Determining the sleep stage of the patient 20 may additionally or alternatively include determining a change in sleep stage of the patient 20 over a period of time, such as several seconds after electrical stimulation is applied. In some examples, a change in sleep stage of the patient in response to electrical stimulation may indicate that the patient 20 is disturbed by the electrical stimulation.

[0244] In a different context, a sleep stage of the patient 20 may affect how treatment is provided to the patient 20. For example, the patient 20 may have no difficulty sleeping in REM sleep, but may experience disordered breathing light sleep. Accordingly, the sleep stage of the patient 20 may be used to determine whether and what kind of therapy to provide to the patient 20. If the sleep stage of the patient 20 is to be determined (822 YES), then the process 800 continues to act 824.

[0245] At act 824, the IPG 12 obtains sleep-stage information indicative of a sleep stage of the patient 20 and / or directly determines the sleep stage of the patient 20. The IPG 12 may determine the sleep-stage information based on information received from the sensors 18. The sleep-stage information may include heart-rate parameters and position parameters, which may be used by the IPG 12 to determine a sleep stage of the patient 20. That is, the sleep stage of the patient 20 may not be sensed directly, but may be determined based on parameters such as heart rate and position.

[0246] Accordingly, in one example, the sensors 18 include at least one accelerometer and at least one heart-rate sensor. The accelerometer may be coupled to the patient 20 such that when the patient 20 moves, the accelerometer senses the movement of the patient 20 as discussed above with respect to act 812. The heart-rate sensor may be used to determine a heart rate of the patient 20, as discussed above with respect to act 820. The IPG 12 may determine the sleep stage of the patient 20 based at least on the heart-rate parameters and / or the position parameters, because certain sleep stages may be associated with higher or lower heart rates (or variations thereof) and / or higher or lower amounts of movement. Other parameters, such as breathing-rate parameters, may alternately or additionally be used to identify and distinguish between sleep stages. As discussed above, sleep-stage information may be useful in at least two examples.

[0247] In a first example, the sleep-stage information may be used to identify a change in sleep stage of the patient 20. If the patient 20 changes a sleep stage in response to electrical stimulation being applied, this may be indicative of the sleep of the patient 20 being disturbed by the electrical stimulation. Accordingly, if the IPG 12 determines that the sleep stage of the patient 20 changes within a threshold period of time after applying the electrical stimulation, the IPG 12 may determine that the sleep of the patient 20 is disturbed by the electrical stimulation. The IPG 12 may therefore modify one or more electrical-stimulation parameters of the electrical stimulation to reduce the intensity of the electrical stimulation based on the sleep- stage information.

[0248] In a second example, the sleep- stage information may be used to determine a sleep stage that the patient 20 is currently in. The IPG 12 may apply different treatment regimens to the patient 20 for different sleep stages. For example, if the patient 20 does not experience disordered breathing in a deep sleep stage, then the IPG 12 may pause stimulation when the patient 20 is in deep sleep. If the patient 20 experiences mild disordered breathing in a light sleep stage, then the IPG 12 may apply electrical stimulation to the patient 20 with one or more electrical-stimulation parameters corresponding to a relatively mild electrical stimulation to the patient 20 while the patient 20 is in light sleep. If the patient 20 experiences significant disordered breathing in in REM sleep, then the IPG 12 may apply electrical stimulation to the patient 20 with one or more electrical-stimulation parameters corresponding to a relatively intense electrical stimulation to the patient 20 while the patient 20 is in REM sleep.

[0249] In other examples, the sleep-stage information may be used in additional or different ways. The sleep-stage information may include multiple types of information from the foregoing examples, in addition to or in lieu of additional information. The process 800 continues to act 826 upon obtaining the sleep-stage information, or if no sleep-stage information is to be determined (822 NO).

[0250] At act 826, a determination is made as to whether to obtain acoustic parameters indicative of respiratory parameters or information. The acoustic parameters may be indicative of sounds such as the patient 20 snoring or being otherwise associated with disturbed breathing. In some examples, as discussed above with respect to act 804, determining the breathing-rate parameters may include analyzing acoustic parameters indicative of the breathing of the patient 20. In some examples, acoustic parameters may be additionally and / or separately used to determine information in addition to, or in lieu of, breathing-rate parameters as discussed below. If acoustic parameters are to be determined (826 YES), then the process 800 continues to act 828.

[0251] At act 828, the IPG 12 determines acoustic parameters indicative of sounds produced by the patient 20. The IPG 12 may determine the acoustic parameters based on parameters received from the sensors 18. In one example, the sensors 18 include at least one acoustic sensor. The acoustic sensor may be positioned near the head of the patient 20 such that sounds produced by the patient 20, such as snoring, are detected by the acoustic sensor.

[0252] As discussed above, acoustic parameters may be used to determine a breathing rate of the patient 20. Acoustic parameters may also be used to determine additional parameters, such as the patient 20 snoring or breathing too loudly. An acoustic waveform captured by an acoustic sensor may be analyzed by the IPG 12 to determine whether the patient 20 is snoring or breathing too loudly. For example, a maximum or average amplitude of the acoustic waveform may be compared to a threshold level corresponding to snoring or loud, labored breathing. The IPG 12 may implement artificial intelligence to learn, over time, what threshold level of sound corresponds to snoring or labored breathing.

[0253] In another example, the IPG 12 may perform a frequency analysis of the acoustic waveform to identify snoring or labored breathing. In some examples, the IPG 12 compares the acoustic waveform to a library of acoustic waveforms known to correspond to snoring or labored breathing. In some examples, the IPG 12 may add to the library over time with waveforms captured from the patient 20 while the patient 20 is snoring, such that the IPG 12 learns over time which acoustic waveforms correspond to snoring. In still other examples, the IPG 12 may implement additional or different methods of identifying snoring or labored breathing from the acoustic parameters. The process 800 continues to act 830 upon obtaining the acoustic parameters, or if no acoustic parameters are to be determined (826 NO).

[0254] At act 830, a determination is made as to whether to determine lung-volume parameters of the patient 20. Lung- volume parameters may be an example of respiratory parameters or information. Lung- volume parameters include parameters indicative of the volume of the lungs of the patient 20. As the patient 20 breathes in, the lungs fill with air and thereby expand in volume. As the patient 20 exhales, the lungs are emptied of air and thereby diminish in volume. Lung- volume parameters may be used to determine breathing-rate parameters, as discussed above at act 804. In some examples, however, lung- volume parameters may be separately used to determine parameters in addition to, or in lieu of, breathing-rate parameters as discussed below. For example, the lung-volume parameters may be used to determine how deeply the patient 20 is breathing. If the lung volume of the patient 20 is relatively small when the patient 20 has breathed in (that is, at the transition between the inhalation and exhalation periods of a breathing cycle), then the IPG 12 may determine that the patient 20 is taking relatively shallow breaths, which may be indicative of disturbed breathing. In another example, if the lung volume of the patient 20 changes rapidly, then the IPG 12 may determine that the patient 20 is gasping and inhaling very rapidly. If lung- volume parameters are to be determined (830 YES), then the process 800 continues to act 832.

[0255] At act 832, the IPG 12 determines lung-volume parameters of the patient 20. The IPG 12 may determine the lung- volume parameters based on parameters received from the sensors 18. In one example, the sensors 18 include at least one pressure sensor, and / or the sensors 18 and / or at least one of the leads 14, 16 includes at least one transthoracic-impedance sensor.

[0256] In a first example, the sensors 18 and / or one or both of the leads 14, 16 may include transthoracic-impedance sensors coupled across the chest of the patient 20. As the patient 20 breathes, the volume of the lungs changes and the impedance between the transthoracic impedance sensors may vary. The IPG 12 may receive this impedance parameters and determine a lung volume of the patient 20 based on the variations in impedance.

[0257] In a second example, the sensors 18 may include one or more pressure sensors. The pressure sensors may sense pressure parameters, which may include changes in pressure in or on the chest of the patient 20 as the patient 20 breathes in and out. For example, a pressure sensor may be externally disposed on the patient, may be disposed in a device configured to interface with the airway of the patient, or be implanted in the chest of the patient 20. As the patient 20 breathes, the change in shape and / or volume of the lungs and / or diaphragm may exert a variable pressure on the pressure sensor. The IPG 12 may receive this pressure parameters and determine a volume of the lungs of the patient 20 based on the variations in pressure caused by the motion of the chest of the patient 20. The process 800 continues to act 834 upon obtaining the lungvolume parameters, or if no lung- volume parameters are to be determined (830 NO).

[0258] At act 834, a determination is made as to whether to determine pulsatility parameters (for example, pulse rate, heart rate, peripheral arterial tone, pulse amplitude fluctuations, and so forth) of the patient 20. Pulsatility parameters may be an example of respiratory parameters or information. If pulsatility parameters are to be determined (834 YES), then the process 800 continues to act 836.

[0259] At act 836, the IPG 12 determines pulsatility parameters of the patient 20. The IPG 12 may determine the pulsatility parameters based on parameters received from the sensors 18. In one example, the sensors 18 include at least one finger- worn peripheral arterial vascular tone sensor. The process 800 continues to act 838 upon obtaining the pulsatility parameters, or if no pulsatility parameters are to be determined (834 NO).

[0260] At act 838, a determination is made as to whether to determine end-tidal CO2 (EtCO2) parameters of the patient 20. EtCO2 parameters may be an example of respiratory parameters or information. EtCO2 parameters include parameters indicative of an amount of carbon dioxide exhaled at the end of each breath. If E1CO2 parameters are to be determined (838 YES), then the process 800 continues to act 840.

[0261] At act 840, the IPG 12 determines EtCCh parameters of the patient 20. The IPG 12 may determine the EtCO2 parameters based on parameters received from the sensors 18, for example, using capnography sensors. The process 800 then ends after act 840 is executed or if the IPG 12 does not obtain EtCO2 parameters (838 NO). As discussed above, the process 800 may be an example of act 708, and act 708 may proceed to act 610. Accordingly, the process 800 may then proceed to act 610.

[0262] Accordingly, the process 800 provides an example of additional sensed parameters which the IPG 12 may obtain and utilize to modify treatment delivered to the patient 20. In some examples, the IPG 12 is preprogrammed to obtain certain examples of the additional sensed parameters identified above. In other examples, the IPG 12 may only obtain certain additional sensed parameters according to acts 608 and / or 610 if one or more criteria are met.

[0263] FIGS. 9-11 discuss examples of different approaches which might be implemented by the IPG 12 to determine whether to obtain additional sensed parameters. For example, FIGS. 9-11 may provide different examples illustrating when information might be acquired and / or determined at acts 608 and 610.

[0264] FIG. 9 illustrates a process 900 of operating the IPG 12 to provide treatment to the patient 20 according to an example. Acts 902-906 of the process 900 are substantially similar or identical to acts 602-606 of the process 600 and are not repeated for brevity. For purposes of example rather than limitation, it is assumed that the therapy-specific indicator determined at act 906 includes a capture index.

[0265] At act 908, the IPG 12 determines whether the therapy delivered to the patient 20 by virtue of the electrical stimulation applied at act 902 is effective. Act 908 may determine whether an example of act 608 is executed. The IPG 12 may determine whether the therapy is effective by comparing the capture index determined at act 906 with a therapy-effectiveness threshold. For example, if the therapy-effectiveness threshold is 0.8, then the capture index must be 0.8 or higher for the IPG 12 to determine that the therapy is effective (908 YES). If the capture index is less than 0.8, then the IPG 12 may determine that the therapy is not effective (908 NO). If the IPG 12 determines that the therapy is effective (908 YES), then the process 900 may continue to act 910. At act 910, the IPG 12 maintains the electrical-stimulation parameters at their current values. Act 910 is substantially similar or identical to act 614 of the process 600. Accordingly, because the therapy is effective (908 YES), additional information (as discussed above with respect to acts 608 and 610) may be bypassed without modifying the electrical-stimulation parameters. Thus, act 908 may determine whether act 608 is executed to obtain additional information. The process 900 then returns to act 902.

[0266] Conversely, if the IPG 12 determines that the therapy is not effective (908 NO), then the process 900 continues to act 912. In one example, determining that therapy is not effective (908 NO) may initiate execution of an example of act 608.

[0267] At act 912, the IPG 12 obtains additional respiratory parameters and / or non-respiratory information (collectively, additional information). Act 912 may include executing the processes of FIGS. 7-8C. In some examples, the IPG 12 may be preprogrammed to obtain certain additional respiratory parameters and / or non-respiratory information if therapy is not effective (908 NO), such as movement parameters, heart-rate parameters, lung-volume parameters, and so forth. That is, the decision blocks in FIGS. 7-8C may not actually be executed by any particular entity, because the information that the IPG 12 is to obtain is preprogrammed into the IPG 12.

[0268] At act 914, the IPG 12 determines at least one patient- specific indicator. Act 914 may be substantially similar or identical to act 610. The IPG 12 may determine the at least one patientspecific indicator based on the respiratory parameters obtained at act 904 and / or based on the additional respiratory parameters and / or non-respiratory information obtained at act 912.

[0269] At act 916, the IPG 12 determines whether to modify one or more electrical- stimulation parameters. Act 916 may be substantially similar or identical to act 612. The IPG 12 may determine whether to modify the one or more electrical-stimulation parameters based on the at least one therapy-specific indicator, the at least one patient-specific indicator, and / or the additional respiratory parameters and / or non-respiratory information. Determining whether to modify the one or more electrical-stimulation parameters, as well as determining which parameters to modify and by what amount, may depend on least in part on a numerical value of the at least one therapy- specific indicator, the at least one patient-specific indicator, and / or the additional respiratory parameters and / or non-respiratory information. The numerical value may include a binary value and / or an analog value. For example, where the at least one patientspecific indicator is indicative of movement of the patient 20, the at least one patient- specific indicator may be binary (indicating, for example, whether the patient 20 rolled or did not roll in response to electrical stimulation) or analog (indicating, for example, a number of degrees that the patient 20 rolled).

[0270] In one example, if the at least one therapy-specific indicator is a capture index and is within a first range of values (for example, 0.6-0.79), then the IPG 12 may increase an intensity of the electrical stimulation by a first amount (for example, by increasing the current magnitude of the electrical stimulation by 0.1 mA). If the at least one therapy-specific indicator is within a second range of values (for example, 0.4-0.59), then the IPG 12 may increase an intensity of the electrical stimulation by a second amount (for example, by increasing the current magnitude of the electrical stimulation by 0.5 mA).

[0271] Simultaneously, however, if the IPG 12 determines that the at least one patient-specific indicator indicates that the sleep of the patient 20 is disturbed (for example, if the at least one patient-specific indicator is indicative of movement of the patient 20, and the patient 20 rolled in response to the electrical stimulation applied at act 902), the IPG 12 may or may not modify the one or more parameters of the electrical stimulation. For example, if the at least one therapyspecific indicator is within the first range of values (indicating that the therapy is nearly effective), then the IPG 12 may forego modifying the electrical- stimulation parameters if the at least one patient- specific indicator indicates that the sleep of the patient 20 is disturbed. However, if the at least one therapy -specific indicator is within the second range of values (indicating that the therapy is far from effective), then the IPG 12 may increase the intensity of the electrical- stimulation parameters even if the at least one patient- specific indicator indicates that the sleep of the patient 20 is disturbed.

[0272] In still other examples, the IPG 12 may implement other rules. Moreover, the at least one therapy- specific indicator may include information other than the capture index, such as an SpO2 level. Similarly, the at least one patient-specific indicator may include information other than the change in position, such as heart-rate parameters, acoustic parameters, lung-volume parameters, and so forth, each of which may be associated with thresholds and / or ranges of values quantitatively associating the at least one patent-specific indicator with respective categories of conditions of the patient 20.

[0273] If the IPG 12 determines that one or more electrical-stimulation parameters 916 are not to be modified (916 NO), then the process 900 continues to act 910, and the electrical stimulation remains unchanged for a subsequent cycle. Otherwise, if the IPG 12 determines that one or more electrical-stimulation parameters are to be modified (916 YES), then the process 900 continues to act 918.

[0274] At act 918, the IPG 12 modifies one or more electrical-stimulation parameters. Modifying the one or more electrical-stimulation parameters may include increasing the intensity of the electrical stimulation (for example, if therapy is not effective) or decreasing the intensity of the electrical stimulation (for example, if the sleep of the patient 20 is being disturbed by the electrical stimulation). As discussed above, modulating the intensity of the electrical stimulation may include decreasing or increasing a value of a particular electrical-stimulation parameter. The optimum intensity of the electrical stimulation may balance effective stimulation of the diaphragm with discomfort felt by the patient 20. The process 900 then returns to act 902.

[0275] Modifying the one or more electrical-stimulation parameters at act 918 may depend at least in part on a method by which electrical stimulation is applied to the patient 20. In some examples, the electrical stimulation may be applied to the patient 20 during or immediately after the inspiration period of the patient 20 for each breathing cycle such that the patient 20 is breathing in while the electrical stimulation is applied. In these examples, modifying the one or more electrical-stimulation parameters may include modifying one or more of an amplitude of electrical stimulation, a timing of the electrical stimulation, a duration of each electricalstimulation pulse, and so forth. In other examples, electrical stimulation may be delivered at a predetermined time and a predetermined respiratory rate, for example, as determined by a physician or determined by the IPG 12 based on the physiological parameters of the patient 20. In these examples, modifying the one or more electrical- stimulation parameters may include, for example, increasing a stimulation current. In still other examples, different parameters of the one or more electrical-stimulation parameters may be modified.

[0276] FIG. 10 illustrates a process 1000 of operating the IPG 12 to provide treatment to the patient 20 according to an example. Acts 1002-1010 of the process 1000 are substantially identical to acts 902-910 of the process 900 and are not repeated for brevity. In the process 1000, however, if the IPG 12 determines that therapy is not effective (1008 NO), then the process 1000 continues to act 1012.

[0277] At act 1012, the IPG 12 determines whether to obtain additional respiratory parameters and / or non-respiratory information (collectively, additional information). In some examples, act 1012 may include the IPG 12 determining whether additional information is available. For example, the IPG 12 may determine whether the patient 20 has provided patient-feedback indicating that the treatment is too weak, is average, or is too strong. If the IPG 12 is determining whether additional information is available at act 1012, then the IPG 12 may determine to obtain additional information if the additional information is available (1012 YES) and continue to act 1016, or may determine not to obtain additional information if the additional information is not available (1012 NO) and continue to act 1014.

[0278] In other examples, act 1012 may additionally or alternatively include the IPG 12 determining whether to obtain additional sensed parameters. The IPG 12 may execute its determination based on any of various factors. In one example, the IPG 12 may obtain additional information only once in a given time period, and act 1012 may therefore include the IPG 12 determining whether the time period has elapsed. In another example, the IPG 12 may obtain additional information only if the therapy- specific indicator is within certain ranges of values, and act 1012 may therefore include the IPG 12 determining whether the therapy- specific indicator is within a certain range of values. For example, if the capture index indicates that treatment is only mildly ineffective (for example, by being between 0.7 and 0.79), then the IPG 12 may determine not to obtain additional information (1012 NO). Conversely, if the capture index indicates that treatment is more than mildly ineffective (for example, by being less than 0.7), then the IPG 12 may determine to obtain additional information (1012 YES).

[0279] After act 1012 is executed, the process 1000 is substantially similar or identical to the process 1000. For example, acts 1010 and 1014-1020 are substantially similar or identical to acts 910 and 912-918, respectively. Accordingly, the process 1000 differs from the process 900 at least inasmuch as, whereas in the process 900 the IPG 12 obtains additional information (act 912) responsive to determining that therapy is not effective (908 NO), in the process 1000 the IPG 12 obtains additional information (act 1016) responsive to determining that therapy is not effective (1008 NO) and determining that additional information should be obtained (1012 YES).

[0280] In both of the processes 900, 1000, however, the IPG 12 maintains the electricalstimulation parameters if therapy is effective (908 YES, 1008 YES). In other examples, the IPG 12 may obtain additional information before determining whether to change the electricalstimulation parameters. FIG. 11 illustrates a process 1100 of operating the IPG 12 to provide treatment to the patient 20 according to an example. Acts 1102-1106 of the process 1100 are substantially identical to acts 902-906 of the process 900 and acts 1002-1006 of the process 1000 and are not repeated for brevity. In the process 1100, however, after determining the therapy-specific indicator at act 1106, the process 1100 continues to act 1108.

[0281] At act 1108, the IPG 12 determines whether to obtain additional information. Act 1108 may be substantially similar or identical to act 1012 of the process 1000. However, act 1108 is executed prior to evaluating the therapy-specific indicator. If the IPG 12 determines that no additional information should be obtained (1108 NO), then the process 1100 continues to act 1110. At act 1110, the IPG 12 determines whether to modify one or more electrical- stimulation parameters. Act 1110 may include the IPG 12 determining whether to modify the one or more electrical-stimulation parameters based at least on the therapy- specific indicator determined at act 1106. Accordingly, act 1110 is similar to acts 908 and 914. In some examples, act 1110 may simply include the IPG 12 determining whether the therapy- specific indicator is above a therapyeffectiveness threshold. However, in other examples, the IPG 12 may determine whether to modify the one or more electrical-stimulation parameters based on which of several different ranges of values the therapy-specific indicator falls within.

[0282] For example, suppose the therapy-specific indicator is a capture index having a value between 0 and 1, and that a value of 0.8 represents a threshold above which therapy is considered to be effective. If the capture index is below 0.8 (that is, between 0 and 0.8), then the IPG 12 may determine that one or more electrical-stimulation parameters should be modified to increase the intensity of the electrical stimulation (1110 YES). If the capture index is slightly above the threshold of 0.8 (for example, between 0.8 and 0.89), then the IPG 12 may determine no electrical-stimulation parameters should be modified (1110 NO). However, if the capture index is well above the threshold of 0.8 (for example, 0.9 to 1), then the IPG 12 may determine that one or more electrical-stimulation parameters should be modified to decrease the intensity of the electrical stimulation (1110 YES). For example, the IPG 12 may determine that the patient 20 is already experiencing undisturbed breathing, and that it might be advantageous to reduce the intensity of the electrical stimulation to minimize a chance of disturbing the sleep of the patient 20 while still delivering an effective dose of electrical stimulation to the patient 20. Accordingly, at act 1110 the IPG 12 determines whether to modify one or more electrical-stimulation parameters based at least on the therapy- specific indicator. If the IPG 12 determines that no electrical-stimulation parameters are to be modified (1110 NO), then the process 1100 continues to act 1112, which is substantially similar or identical to act 910. If the IPG 12 determines that one or more electrical-stimulation parameters are to be modified (1110 YES), then the process 1100 continues to act 1114, which is substantially similar or identical to act 916.

[0283] Returning to act 1108, the IPG 12 may obtain additional information in addition to the respiratory parameters determined at act 1104. In some examples, the IPG 12 may be preprogrammed to obtain certain additional information. In various examples, the IPG 12 may obtain additional information based on the therapy- specific indicator, such as if the therapyspecific indicator falls within a range of values. In at least one example, the IPG 12 may obtain additional information after a certain period of time. For example, although the IPG 12 may determine the respiratory parameters at act 1104 once per breathing cycle of the patient 20, the IPG 12 may only obtain additional information once per minute, or any other period of time. In other examples, the IPG 12 may determine whether to obtain additional information based on other criteria. If the IPG 12 determines that additional information should be obtained (1108 YES), then the process 1100 continues to act 1116.

[0284] At act 1116, the IPG 12 obtains additional respiratory parameters and / or non-respiratory information (collectively, additional information). Act 1116 may be substantially similar or identical to act 912.

[0285] At act 1118, the IPG 12 determines at least one patient- specific indicator based at least in part on the additional information obtained at act 1116. Act 1118 may be substantially similar or identical to act 912.

[0286] At act 1110, the IPG 12 determines whether to modify one or more electrical-stimulation parameters. Act 1110 may be substantially similar to act 914. However, act 1110 may include the IPG 12 determining whether to modify the one or more electrical- stimulation parameters based not only on the additional information obtained at act 1116 and / or the at least one patientspecific indicator obtained at act 1118, but may also include the IPG 12 determining, based at least on the therapy-specific indicator, whether the treatment is effective. That is, act 1110 may include a combination of acts 908 and 914 of the process 900. Accordingly, the IPG 12 evaluates whether to modify one or more electrical- stimulation parameters based on all information available to the IPG 12, including the respiratory parameters determined at act 1104, the at least one therapy- specific indicator determined at act 1106, the additional respiratory parameters and / or non-respiratory information obtained at act 1116, and the at least one patient-specific indicator determined at act 1118.

[0287] In some examples, the IPG 12 may execute one or more rules to determine, based on all available information, whether to modify the one or more electrical-stimulation parameters. In various examples, the IPG 12 may implement rules based on where certain values (for example, a capture index, SpO2, a breathing rate, an amount of movement, and so forth) fall within certain ranges. That is, information obtained by the IPG 12 may be quantified and compared to one or more numerical ranges. As discussed above, one example includes quantifying a capture index and classifying the capture index by determining which range of numerical values the capture index falls within. The IPG 12 may execute rules to determine, based on the classification(s) of any applicable values, whether to modify one or more electrical stimulation values.

[0288] In some examples, each classification may correspond to a numerical value by which to increase or decrease one or more electrical-stimulation parameters. For example, suppose that the therapy- specific indicator includes a capture index. A first range of capture-index values between 0.6 and 0.79 may correspond to relatively ineffective therapy. If the capture index is within the first range of values, the IPG 12 may determine that the current of the electrical stimulation should be increased by 0.1 mA. A second range of capture-index values between 0.4 and 0.59 may correspond to significantly ineffective therapy. If the capture index is within the second range of values, the IPG 12 may determine that the current of the electrical stimulation should be increased by 0.5 mA.

[0289] This example rule may be combined with other rules. For example, suppose that a patient-specific indicator includes a change in heart rate within a period of time (for example, one second, three seconds, and so forth) after electrical stimulation is applied. If the patient 20 experiences a spike in heart rate, this may indicate that the sleep of the patient 20 is disturbed. Accordingly, a first range of heart-rate-increase values between zero and three beats-per-minute (BPM) may correspond to a negligible impact. If the heart-rate-increase of the patient 20 is within the first range, then the IPG 12 may determine that the current of the electrical stimulation should not be changed. A second range of heart-rate-increase values between four and 10 beats- per-minute (BPM) may correspond to a minor disturbance. If the heart-rate-increase of the patient 20 is within the second range, then the IPG 12 may determine that the cunent of the electrical stimulation should be reduced by 0.3 mA. A third range of heart-rate-increase values above 11 beats -per-minute (BPM) may correspond to a major disturbance. If the heart-rate- increase of the patient 20 is within the third range, then the IPG 12 may determine that the current of the electrical stimulation should be reduced by 1 mA.

[0290] Suppose that the two example rules discussed above for capture index and heart rate are combined. If the IPG 12 determines that the capture index is 0.5, which is within the second range of capture-index values, then the IPG 12 may determine that the current of the electrical stimulation should be increased by 0.5 mA. If the IPG 12 determines that the heart-rate-increase value is seven, which is within the second range of heart-rate-increase values, then the IPG 12 may determine that the current of the electrical stimulation should be reduced by 0.3 mA. Taking these two results together, the IPG 12 may determine that the current of the electrical stimulation should be increased by 0.2 mA (that is, 0.5 mA - 0.3 mA). In this example, the IPG 12 determines that the electrical stimulation parameter to be modified is the current magnitude, and that the current magnitude should be increased by 0.2 mA.

[0291] In other examples, other rules may be implemented in addition to, and / or in lieu of, the foregoing examples. In some examples, the IPG 12 may implement certain override rules that take precedence over other rules. For example, if the IPG 12 determines, based on patientfeedback information received at act 1116 indicating that the patient 20 is experiencing discomfort and wishes to reduce the intensity of the electrical stimulation, then the IPG 12 may reduce the intensity of the electrical stimulation even if an SpO2 or capture-index value indicates that therapy is not very effective. Thus, the IPG 12 may implement a hierarchy of rules.

[0292] Furthermore, in some examples, the IPG 12 may execute act 1110 using non-rules-based methodologies. For example, the IPG 12 may implement artificial-intelligence-based solution to determine, based on all available information, whether to modify one or more electricalstimulation parameters. In some examples, the artificial-intelligence-based solution may be trained using treatment information from other patients. In various examples, the artificialintelligence-based solution may be trained using treatment information from the patient 20. That is, in some examples, the IPG 12 may learn over time as the IPG 12 provides therapy to the patient 20. For example, the IPG 12 may learn that, when the patient 20 is in a right-side sleeping position, the patient 20 is more prone to disturbed sleep, or that when the patient 20 is in a deep sleep stage, that the patient 20 is less prone to disturbed sleep. In another example, the IPG 12 may learn that increasing the intensity of the electrical stimulation by modifying certain parameters (for example, increasing a duration of the electrical stimulation) is just as effective at increasing therapy efficacy (for example, increasing capture index or SpO2 as the therapyspecific indicator) as modifying other parameters (for example, increasing a current magnitude of the electrical stimulation) but is less likely to disturb the sleep of the patient 20. Accordingly, the IPG 12 may learn to modify certain electric al- stimulation parameters in lieu of other electrical-stimulation parameters as the IPG 12 provides therapy to the patient 20 and collects additional information.

[0293] To illustrate examples of the foregoing, FIGS. 12-16 provide various concrete examples of operating the IPG 12. FIGS. 12-16 may represent concrete examples of certain implementations of the process 1100.

[0294] FIG. 12 illustrates a process 1200 of operating the IPG 12 according to a first example. In the first example, the IPG 12 obtains breathing-rate parameters as respiratory information, and determines a capture index based on the breathing-rate parameters as the therapy-specific indicator. The IPG 12 also obtains patient feedback as non-respiratory information, and determines whether to modify the one or more electrical-stimulation parameters based on the capture index and the patient-feedback information. In this example, the patient-feedback information includes an instruction to reduce the intensity of the electrical stimulation, which overrides any evaluation of the capture index.

[0295] At act 1202, the IPG 12 applies electrical stimulation to the patient 20. Act 1202 may be an example of act 1102. For example, the lead 14 may be implanted in the vasculature of the patient 20 (for example, adjacent the phrenic nerve or the hypoglossal nerve, or may include a nerve cuff disposed around, and operatively coupled to, the target nerve of the patient 20).

[0296] For example, the electrical stimulation may be applied to the patient 20 during or immediately after the inspiration period of the patient 20 for each breathing cycle such that the patient 20 is breathing in while the electrical stimulation is applied. In other examples, electrical stimulation may be delivered at a predetermined time and a predetermined respiratory rate, for example, as determined by a physician or determined by the IPG 12 based on the physiological parameters of the patient 20. At act 1204, the IPG 12 determines breathing-rate parameters for the patient 20. Act 1204 may be an example of act 1104, whereby the breathing-rate parameters is an example of respiratory information. For example, the lead 16 may include transthoracic-impedance sensors coupled to the patient 20. As the patient 20 breathes and the chest of the patient 20 moves, the impedance sensed by the transthoracic-impedance sensors may vary. The IPG 12 may determine, based on cyclical variations in the impedance, the breathing rate of the patient 20. Determining the breathing rate may include determining a waveform capturing the breathing rate of the patient 20. In other examples, the lead 14 may perform a similar function; that is, the lead 14 may not only provide electrical stimulation to the patient 20, but may also sense parameters such as breathing-rate parameters.

[0297] At act 1206, the IPG 12 determines a capture index. Act 1206 may be an example of act 1106. The IPG 12 may determine the capture index based on the breathing-rate parameters. For example, as discussed above, the breathing-rate parameters may include a waveform of the breathing of the patient 20, and a capture index may be determined by dividing the spectral power in the SFB by the spectral power in the RFB. The capture index may be a value between 0 and 1. For purposes of this example, suppose the capture index is 0.7.

[0298] At act 1208, the IPG 12 receives patient-feedback information from the patient 20. Act 1208 may be an example of act 1116 and / or act 1118, because the patient-feedback information may be both non-respiratory information and the patient- specific indicator. For example, the patient 20 may have awoken in response to the electrical stimulation provided at act 1202 or previously. Thus, the patient 20 may determine that the electrical stimulation is too intense and should be reduced in intensity. The patient 20 may therefore provide, via a touchscreen of the display 116, patient-feedback indicating that the intensity of the electrical stimulation should be reduced. In some examples, the display 116 may display different levels of intensity of the electrical stimulation, such as a number between 0 and 10. The patient 20 may manually reduce the intensity from, say, seven to five. In another example, the display 116 may display actual electrical-stimulation parameters and values, such as a current magnitude between 0 mA and 10 mA. The patient 20 may manually reduce the current magnitude from, say, 7 mA to 5 mA. In other examples, other approaches to soliciting and receiving patient-feedback from the patient 20 may be implemented. For purposes of this example, suppose that the patient 20 manually reduces the current magnitude from 7 mA to 5 mA. At act 1210, the IPG 12 determines that the intensity of the electrical stimulation should be reduced. Act 1210 may be an example of acts 1110- YES and 1114. For purposes of this example, suppose that patient feedback to reduce the intensity of the electrical stimulation overrides the capture index. Thus, although a capture index of 0.9 might indicate that therapy is not effective and that the intensity of the electrical stimulation should be increased, the patient feedback reducing the current magnitude from 7 mA to 5 mA may override the capture index. The IPG 12 may therefore reduce the current magnitude of the electrical stimulation to 5 mA and subsequently apply electrical stimulation with the new parameters.

[0299] FIG. 13 illustrates a process 1300 of operating the IPG 12 according to a second example. In the second example, the IPG 12 obtains breathing-rate parameters and blood-oxygen parameters as respiratory parameters. The IPG 12 determines two therapy-specific indicators, including a capture index based on the breathing-rate parameters and an SpO2 level based on the blood-oxygen parameters. The IPG 12 determines whether to modify the one or more electricalstimulation parameters based on the capture index and the SpO2 level. In this example, the capture index and the SpO2 level suggest that the intensity of the electrical stimulation should be increased.

[0300] At act 1302, the IPG 12 applies electrical stimulation to a target nerve of the patient 20. Act 1302 may be an example of act 1102. For example, the lead 14 may be implanted in the vasculature of the patient 20 (for example, adjacent the phrenic nerve or the hypoglossal nerve, or may include a nerve cuff disposed around, and operatively coupled to, the target nerve of the patient 20).

[0301] For example, the electrical stimulation may be applied to the patient 20 during or immediately after the inspiration period of the patient 20 for each breathing cycle such that the patient 20 is breathing in while the electrical stimulation is applied. In other examples, electrical stimulation may be delivered at a predetermined time and a predetermined respiratory rate, for example, as determined by a physician or determined by the IPG 12 based on the physiological parameters of the patient 20.

[0302] At act 1304, the IPG 12 determines breathing-rate parameters for the patient 20. Act 1304 may be an example of part of act 1104, whereby the breathing-rate parameters are an example of respiratory information. For example, the lead 16 may include transthoracic-impedance sensors coupled to the patient 20 in a similar manner as discussed above with respect to act 1204. At act 1306, the IPG 12 determines sensed blood-oxygen parameters for the patient 20. Act 1306 may be an example of part of act 1104, whereby the blood-oxygen parameters is another example of respiratory information. For example, the sensors 18 may include at least one pulse oximeter coupled to a finger of the patient 20. The IPG 12 receives the blood-oxygen parameters from the pulse oximeter for analysis.

[0303] At act 1308, the IPG 12 determines a capture index based on the breathing-rate parameters. Act 1308 may be an example of part of act 1106, and may be substantially similar or identical to act 1206. For purposes of this example, suppose that the capture index is 0.75.

[0304] At act 1310, the IPG 12 determines an SpO2 level based on the blood-oxygen parameters. Act 1310 may include interpreting the raw blood-oxygen parameters received from the pulse oximeter to obtain an SpO2 level, which may be expressed as a percentage between 0% and 100%. For purposes of this example, suppose the SpO2 level is 92%.

[0305] At act 1312, the IPG 12 increases the intensity of the electrical stimulation based on the capture index and the SpO2 level. Act 1312 may be an example of acts 1110- YES and 1114. The IPG 12 may determine, based on the capture index and the SpO2 level, that the therapy is not effective and should be intensified. For example, the IPG 12 may determine that if the capture index is 0.6-0.79, and if the SpO2 level is between 90% and 95%, that the electrical stimulation should be intensified by a certain amount. For purposes of example, support the IPG 12 increases the current magnitude for subsequent electrical stimulation by 1 mA. Different, lower ranges might correspond to intensifying the electrical stimulation by greater amounts, such as by increasing the current magnitude by greater amounts. In other examples, other rules and / or ranges of values might be implemented.

[0306] FIG. 14 illustrates a process 1400 of operating the IPG 12 according to a third example. The third example is substantially similar to the second example of the process 1300. In the third example, however, suppose that the capture index remains 0.75 but the SpO2 level is 99%. Acts 1402-1410 are substantially identical to acts 1302-1310, respectively, except that in act 1410 (corresponding to act 1310), the SpO2 level is 99% rather than 92%.

[0307] At act 1412, the IPG 12 decreases the intensity of the electrical stimulation based on the capture index and the SpO2 level. Act 1412 may be an example of acts 1110- YES and 1114. The IPG 12 may determine, based on the capture index and the SpO2 level, that the therapy is effective and should be reduced in intensity. For example, although the capture index may fall within a range of 0.6-0.79, which may suggest mildly ineffective therapy, the SpO2 level falls within a range of 98-100%, which may suggest that the therapy is very effective and the patient 20 is experiencing normal breathing. In some examples, the SpO2 level may be a more direct indication of the effectiveness of therapy, and if the SpO2 level is above 98% the IPG 12 may determine that therapy is very effective even if the capture index is relatively low. Accordingly, the SpO2 level being between 98% and 100% may override the relatively low capture index and yield a decrease in intensity of the electrical stimulation.

[0308] FIG. 15 illustrates a process 1500 of operating the IPG 12 according to a fourth example. In the fourth example, the IPG 12 obtains breathing-rate parameters as respiratory information and determines a capture index based on the breathing-rate parameters as a therapy-specific indicator. The IPG 12 also receives patient- movement parameters as non-respiratory information, and determines whether the patient is rolling as a patient-specific indicator. The IPG 12 determines whether to modify the one or more electrical-stimulation parameters based on the capture index and the patient rolling. In this example, the patient rolling indicates that electrical stimulation should be paused.

[0309] Acts 1502-1506 are substantially similar or identical to acts 1202-1206, and are not repeated for purposes of brevity.

[0310] At act 1508, the IPG 12 receives patient-movement parameters. For example, the sensors 18 may include one or more accelerometers coupled to the patient 20. The accelerometers may indicate a change in position of the patient for a period of time after electrical stimulation is applied at act 1502, such as one to three seconds after applying stimulation. The patientmovement parameters may be used to determine whether and to what extent the patient 20 is rolling due to a disturbance in sleep caused by the electrical stimulation.

[0311] At act 1510, the IPG 12 determines a change in position of the patient 20 (that is, the patient 20 rolling) based on the patient-movement parameters. The patient-movement parameters may include raw acceleration data which can be analyzed to determine whether the patient 20 rolled over in response to the electrical stimulation. For example, if the patient 20 moved from a prone position to a right-side position in the three seconds following electrical stimulation at act 1502, the patient- specific indicator may include an indication that the patient 20 rolled in response to the electrical stimulation. At act 1512, the IPG 12 pauses the delivery of electrical stimulation to the patient 20. For example, regardless of the value of the capture index determined at act 1506, the IPG 12 may determine that the electrical stimulation should be paused based on the patient- specific indicator (that is, the patient rolling). The IPG 12 may pause the electrical stimulation for a set period of time, such as one minute. Pausing the electrical stimulation may be considered to be one example of modifying the electrical- stimulation parameters. In some examples, the period of time may vary and depend on certain factors, such as how recently the patient 20 previously rolled, if at all, in response to electrical stimulation. For example, if the patient 20 rolled very recently in response to electrical stimulation, the electrical stimulation may be paused for a longer period of time, such as five minutes.

[0312] In some examples, the IPG 12 may modify one or more electrical- stimulation parameters in addition to pausing the electrical stimulation. For example, the IPG 12 may reduce the intensity of the electrical stimulation once stimulation is resumed. In some examples, the IPG 12 may use the capture index determined at act 1506 to determine whether and by how much to modify the one or more electrical-stimulation parameters. For example, if the capture index is above a threshold value corresponding to highly effective therapy, the IPG 12 may determine that the intensity of the electrical stimulation may be safely reduced without resulting in ineffective therapy.

[0313] FIG. 16 illustrates a process 1600 of operating the IPG 12 according to a fifth example. In the fifth example, the IPG 12 obtains blood-oxygen parameters as respiratory information, and determines an SpO2 based on the blood-oxygen parameters as the therapy-specific indicator. The IPG 12 also obtains patient-feedback information as non-respiratory information, and determines whether to modify the one or more electrical- stimulation parameters based on the SpO2 and the patient-feedback information. In this example, the patient-feedback information includes an instruction to reduce the intensity of the electrical stimulation, which overrides any evaluation of the SpO2.

[0314] At act 1602, the IPG 12 applies electrical stimulation to a target nerve of the patient 20. Act 1602 may be an example of act 1102. For example, the lead 14 may be implanted in the vasculature of the patient 20 (for example, adjacent the phrenic nerve or the hypoglossal nerve, or may include a nerve cuff disposed around, and operatively coupled to, the target nerve of the patient 20). For example, the electrical stimulation may be applied to the patient 20 during or immediately after the inspiration period of the patient 20 for each breathing cycle such that the patient 20 is breathing in while the electrical stimulation is applied. In other examples, electrical stimulation may be delivered at a predetermined time and a predetermined respiratory rate, for example, as determined by a physician or determined by the IPG 12 based on the physiological parameters of the patient 20.

[0315] At act 1604, the IPG 12 determines sensed blood-oxygen parameters for the patient 20. Act 1604 may be an example of part of act 1104, whereby the blood-oxygen parameters are another example of respiratory information. For example, the sensors 18 may include at least one pulse oximeter coupled to a finger of the patient 20. The IPG 12 receives the blood-oxygen parameters from the pulse oximeter for analysis.

[0316] At act 1606, the IPG 12 determines an SpO2 level based on the blood-oxygen parameters. Act 1606 may be an example of act 1106, with the SpO2 level being an example of a therapyspecific indicator. Act 1606 may include interpreting the raw blood-oxygen parameters received from the pulse oximeter to obtain an SpO2 level, which may be expressed as a percentage between 0% and 100%. For purposes of this example, suppose the SpO2 level is 97%. In some examples, acts 1604 and 1606 may include determining sensed blood-oxygen parameters, and determining an SpO2 level therefrom, over a period of time. For example, the IPG 12 may do so if the IPG 12 is evaluating the effectiveness of therapy based on a variation in the SpO2 level of the patient 20 over the period of time.

[0317] At act 1608, the IPG 12 determines a change in position of the patient 20 (that is, the patient 20 rolling) based on the patient-movement parameters. The patient-movement parameters may include raw acceleration data which can be analyzed to determine whether the patient 20 rolled over in response to the electrical stimulation. For example, if the patient 20 moved from a prone position to a right-side position in the three seconds following electrical stimulation at act 1502, the patient- specific indicator may include an indication that the patient 20 rolled in response to the electrical stimulation.

[0318] At act 1610, the IPG 12 pauses the delivery of electrical stimulation to the patient 20. For example, regardless of the value of the SpO2 determined at act 1606, the IPG 12 may determine that the electrical stimulation should be paused based on the patient- specific indicator (that is, the patient rolling). The IPG 12 may pause the electrical stimulation for a set period of time, such as one minute. Pausing the electrical stimulation may be considered to be one example of modifying the electrical- stimulation parameters. In some examples, the period of time may vary and depend on certain factors, such as how recently the patient 20 previously rolled, if at all, in response to electrical stimulation. For example, if the patient 20 rolled very recently in response to electrical stimulation, the electrical stimulation may be paused for a longer period of time, such as five minutes.

[0319] In some examples, the IPG 12 may modify one or more electrical- stimulation parameters in addition to pausing the electrical stimulation. For example, the IPG 12 may reduce the intensity of the electrical stimulation once stimulation is resumed. In some examples, the IPG 12 may use the SpO2 determined at act 1606 to determine whether and by how much to modify the one or more electrical-stimulation parameters. For example, if the SpO2 is above a threshold value corresponding to highly effective therapy, the IPG 12 may determine that the intensity of the electrical stimulation may be safely reduced without resulting in ineffective therapy. In another example, if the SpO2 has varied by less than a threshold amount within a certain period of time corresponding to highly effective therapy, the IPG 12 may determine that the intensity of the electrical stimulation may be safely reduced without resulting in ineffective therapy.

[0320] FIGS. 12-16 provide various examples of operating the treatment system 10. In other examples, the treatment system 10 may utilize additional or different sensors and / or analyze additional or different information to determine whether to modify the electrical- stimulation parameters, as discussed above. Accordingly, alternative examples are within the scope of the disclosure.

[0321] FIG. 17 illustrates a graphical depiction of an electrical stimulation pulse train according to an example. The trace 1710 illustrates an electrical stimulation waveform comprising multiple pulse train envelopes 1720 separated by a time between pulse trains 1730 on the order of milliseconds. The pulse train 1710 is further characterized by a pulse train period 1765 on the order of milliseconds which corresponds to the stimulation frequency or rate. The pulse train envelope 1720 defines the maximum pulse amplitude 1740 as the maximum pulse amplitude within the pulse train. Each pulse train 1720 includes a series of individual pulses characterized by a pulse train duration 1750 on the order of milliseconds, a pulse width 1760 on the order of microseconds, and a pulse period 1765 on the order of microseconds that defines a pulse frequency. As illustrated in FIG. 17, the individual pulses may not all have the same amplitude 1745 and may vary in amplitude so as to ramp up the energy stimulation and / or ramp down the energy stimulation. In some examples, the pulse envelope may not include a ramp up and / or a ramp down. Each pulse train envelope may have a pulse train duration 1750 on the order of milliseconds. Each pulse train may include a ramping up period 1780 and / or a ramping down period 1785. Furthermore, the stimulation energy may ramp up and / or ramp down over multiple pulse trains.

[0322] As discussed above, electrical stimulation may be applied to the patient 20 once the patient 20 is asleep or once sleep-indication conditions are satisfied (or once the patient has been asleep or sleep-indication conditions have been satisfied for a threshold period of time). In various examples, the IPG 12 may determine whether the patient 20 is asleep or whether sleepindication conditions are satisfied based on one or more sleep parameters indicative of whether the patient 20 is asleep, such as heart rate and movement. The IPG 12 may receive parameters indicative of the sleep parameters from the sensors 18, which may include heart-rate sensors, movement sensors, and so forth. Once the IPG 12 determines that the patient 20 is asleep or determines that sleep -indication conditions are satisfied based on the one or more sleep parameters or determines that one or more sleep indication conditions are satisfied, the IPG 12 may begin therapy by applying electrical stimulation. In other examples, electrical stimulation may be applied to the patient 20 even while the patient 20 is awake. Accordingly, in some examples, treatment may be provided to the patient 20 regardless of whether or not the patient 20 is asleep.

[0323] The sleep-indication conditions may include detected movement of the patient. For example, movement detected by one or more accelerometers may provide movement data that may serve as a proxy for the actual sleep state of the patient. Patient activity, motion, position, and pitch as detected, for example, by an accelerometer, may be indicative of sleep particularly when combined with a time of day that corresponds to a regular sleeping time of the patient. Thus, the sleep indication conditions may further include pre-programmed stop and start times, a pre-programmed duration, and pre-programmed thresholds for patient pitch and patient movement. Optionally, the sleep indication conditions may include a patient position (for example, prone, supine, and so forth) and / or changes in physiological parameters, such as a reduction in heart rate. The IPG 12 may be pre-programmed to deliver therapy based on satisfaction of the sleep indication conditions. Various controllers, such as the controller or controllers 50 within or coupled to the treatment system 10, may execute various operations discussed above. Using data stored in associated memory and / or storage, the controller(s) also executes one or more instructions stored on one or more non-transitory computer-readable media, which the controller(s) may include and / or be coupled to, that may result in manipulated data. In some examples, the controller(s) may include one or more processors or other types of controllers. In one example, the controller(s) is or includes at least one processor. In another example, the controller(s) performs at least a portion of the operations discussed above using an application-specific integrated circuit tailored to perform particular operations in addition to, or in lieu of, a general-purpose processor. As illustrated by these examples, examples in accordance with the present disclosure may perform the operations described herein using many specific combinations of hardware and software and the disclosure is not limited to any particular combination of hardware and software components. Examples of the disclosure may include a computer-program product configured to execute methods, processes, and / or operations discussed above. The computer-program product may be, or include, one or more controllers and / or processors configured to execute instructions to perform methods, processes, and / or operations discussed above.

[0324] The Bluetooth connection and corresponding circuitry in each of computing device 100 and IPG 12 can use Bluetooth personal area network (PAN) technology, Bluetooth Low Energy® (BLE) technology, or other Bluetooth variant technologies. BLE is a lower power variant of Bluetooth PAN technology, which uses frequency-hopping wireless technology in the 2.4 GHz unlicensed radio band to interconnect nearby devices. BLE facilitates infrequent short- range wireless data communication between devices, while utilizing very little power (for example, 0.01 to 0.5 watts). In still other examples, communication connection 30 can utilize other wireless technologies and circuitry. For example, wireless connection 30 can be formed using a near-field communication (NFC) compliant technology. NFC is a set of communication protocols that enable two electronic devices to establish communication by bringing the devices within close distance of each other.

[0325] In some examples, the computing device 100 provides a display with a graphical user interface having features, as disclosed herein, that facilitate improved review of patient information by a clinician monitoring the treatment of the patient. Moreover, in some examples, the computing device 100 may provide an interface through which input may be provided to the IPG 12. For example, a user may use the computing device 100 to provide input indicating that current treatment is, for example, too intense and should be reduced to improve patient comfort. To this end, in some examples, the computing device 100 is a mobile computing device such as a tablet computer, a laptop computer, and so forth, though this need not be the case in all examples.

[0326] In some examples, the computing device 100 may include or be coupled to one or more devices to enable communication with the IPG 12 via the communication connection 30. For example, the computing device 100 may be a tablet computer or other type of computer, and may be coupled to an external device to communicate with, and program, the IPG 12. In one example, the computing device 100 may be coupled to an external programming device, which may be referred to as a programming wand, via a wired connection, such as a USB connection. Accordingly, the computing device 100 may communicate with the programming device via a wired connection, and the programming device may communicate with the IPG 12 via a wireless connection. In some examples, the programming device may communicate with the IPG 12 via a magnetic inductive communication link when the programming device is within a proximity of the IPG 12. In various examples, therefore, the computing device 100 may include or be coupled to one or more devices to enable wireless communication with the IPG 12 via the communication connection 30. In some examples, the computing device 100 may include multiple devices, for example, a tablet computer used at least to interface with a user, as well as a programming device used to program and / or provide input to the IPG 12.

[0327] FIG. 2 illustrates a block diagram of the computing device 100 according to an example. While in some examples the computing device 100 is a tablet type of computer or a mobile phone such as a smartphone, the computing device 100 can include other types of computers and is therefore described in the context of a general computing device. In its most basic configuration, the computing device 100 includes at least a processing unit 102 and a memory 104. Depending on the exact configuration and type of computing device, the memory 104 may be volatile (such as RAM), non-volatile (such as ROM, flash memory, and so forth) or some combination of the two. This most basic configuration is illustrated in FIG. 2 by a dashed line 106.

[0328] Additionally, the computing device 100 may also have additional features and / or functionality. For example, the computing device 100 may also include additional storage (removable and / or non-removable) including, but not limited to, magnetic or optical disks or tapes, USB flash drives, memory cards, and so forth. Such additional storage is illustrated in FIG. 2 by a removable storage 108 and a non-removable storage 110. Computer- storage media may include volatile and / or nonvolatile media, removable and / or non-removable media, and so forth, implemented in any method or technology for storage of information such as computer- readable instructions, data structures, program modules or other data. The memory 104, the removable storage 108, and the non-removable storage 110 are all examples of computer- storage media, also referred to as non-transitory computer-readable media. Computer- storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CDROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and which can be accessed by the computing device 100. Any such computer- storage media may be part of computing device 100.

[0329] System memory 104 may include operating system 130, one or more programming modules or applications 132, and program data 134. Operating system 130, for example, may be suitable for controlling the operation of the computing device 100. As stated above, a number of program modules 132 and data files 134 may be stored in system memory 104, including operating system 130. While executing on processing unit 102, programming modules or applications 132 may perform processes including, for example, one or more methods described herein, using one or more of the GUI screens or windows shown and described herein.

[0330] Program modules or applications may include routines, programs, components, data structures, and other types of structures that may perform particular tasks or that may implement particular abstract data types. Moreover, disclosed examples may be practiced with other computer-system configurations, including multiprocessor systems, microprocessor-based or programmable consumer electronics, minicomputers, mainframe computers, and the like. Disclosed examples may also be practiced in distributed computing environments where tasks are performed by remote processing devices linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.

[0331] Furthermore, some disclosed examples may be practiced in an electrical circuit including discrete electronic elements, packaged or integrated electronic chips containing logic gates, a circuit utilizing a microprocessor, or on a single chip containing electronic elements or microprocessors. Some disclosed examples may also be practiced using other technologies capable of performing logical operations such as, for example, AND, OR, and NOT, including but not limited to mechanical, optical, fluidic, and quantum technologies.

[0332] The computing device 100 may also contain one or more communications connections 112 that allow the device to communicate with other devices. The communications connections 112 can include, for example, wired media connections such as a wired network or direct-wired connection, and wireless media connections such as acoustic, RF, infrared, and other wireless media connections. In some examples, communications connections 112 are configured to provide communication between the computing device 100 and IPG 12 of treatment system 10 through the above-described communication connection 30. Thus, in some examples, the communication connections 112 include circuitry configured to provide communication connection 30 as a wireless communication connection as described above.

[0333] In still other examples, such as in which the computing device 100 is coupled with or replaced by remote or cloud-based computing device(s) 38 for some or all of the processing functions described herein, communication circuitry 112 can communicate through a connection 32 and an internet or other network 34, to the computing device(s) 38. In still other examples, the processing functions described herein are performed without the use of a local computing device 100, and are instead incorporated into the treatment system 10 and / or the computing device(s) 38. In such examples, treatment system 10 could include communication connections 40 allowing communication through the network 34 to device(s) 38. In some examples, the treatment system 10 performs at least a portion of the processing functions described herein, and a remaining portion, if any, of the processing functions may be performed by the computing device 100 and / or one or more alternative or additional computing devices, such as the remote or cloud-based computing devices 38. The following description is provided in the context of processing functions being provided at least partially by computing device 100, but those of skill in the art will understand that such functions can be implemented outside of computing device 100.

[0334] In some examples the computing device 100 has, or can be coupled to, a touch screen display device 116 which provides a touch-based GUI. The computing device 100 may also have, or be coupled to, one or more input devices 114, such as a keyboard, mouse, pen, voice input device, and so forth, for providing other input (for example, user input, such as patientfeedback or clinician inputs) to the computing device 100. The computing device 100 may be coupled to one or more other output devices 118 such as speakers, a printer, a vibration generator, and so forth. Further, display device 116, input devices 114 and output devices 118 can all be considered to be separate from, or alternatively part of, the computing device 100. The computing device 100 can be provided with a portable or non-portable power source 120, such as a battery pack, a transformer, a power supply, or the like. The power source 120 provides power for computations, communications and so forth by the computing device 100.

[0335] Having thus described several aspects of at least one embodiment, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art.

[0336] Such alterations, modifications, and improvements are intended to be part of, and within the spirit and scope of, this disclosure. Accordingly, the foregoing description and drawings are by way of example only.

Claims

What is claimed is:CLAIMS1. A system for treating disordered breathing in a patient, the system comprising: at least one electrical-pulse generator comprising at least one controller and at least one power source, the at least one electrical-pulse generator being configured to generate at least one electrical stimulation; at least one lead configured to be coupled to the at least one electrical-pulse generator and being configured to be implanted in the patient to deliver the at least one electrical stimulation to a target nerve of the patient and comprising at least one first sensor configured to sense physiologic information comprising respiratory information, the target nerve comprising a phrenic nerve; and at least one second sensor configured to detect at least one patient parameter comprising at least one non-respiratory parameter of the patient, the at least one controller being configured to provide, via the at least one lead, at least one first electrical stimulation having one or more stimulation parameters to the target nerve of the patient to treat disordered breathing in the patient, receive, from the at least one lead, the respiratory information indicative of at least one respiratory parameter of the patient, determine, based on the respiratory information, a therapy- specific indicator indicative of an effect of the at least one first electrical stimulation on respiration of the patient, receive, from the at least one second sensor, non-respiratory information indicative of the at least one non-respiratory parameter of the patient, determine, based on the non-respiratory information, a patient-specific indicator relating to at least one condition of the patient, modify, based on at least one of the therapy-specific indicator or the patientspecific indicator, at least one stimulation parameter of the at least one electrical stimulation, and provide, via the at least one lead, at least one second electrical stimulation having the modified at least one stimulation parameter to treat the patient.

2. The system of claim 1, wherein the at least one controller is further configured to: receive patient-feedback information from the patient; and modify the at least one stimulation parameter based on the patient-feedback information.

3. The system of claim 2, wherein modifying the at least one stimulation parameter comprises modifying a current level of the at least one first electrical stimulation.

4. The system of claim 1, wherein modifying the at least one stimulation parameter comprises modifying a current level of the at least one first electrical stimulation.

5. The system of claim 4, wherein modifying the current level of the at least one first electrical stimulation comprises increasing the current level of the at least one first electrical stimulation.

6. The system of claim 4, wherein modifying the current level of the at least one first electrical stimulation comprises decreasing the current level of the at least one first electrical stimulation.

7. The system of claim 1, wherein the at least one lead comprises one or more electrodes.

8. The system of claim 7, wherein one or more leads of the at least one lead are configured to be implanted in a lumen proximate the target nerve of the patient.

9. The system of claim 1, wherein the at least one lead comprises one or more nerve cuffs.

10. The system of claim 9, wherein at least one nerve cuff of the one or more nerve cuffs is configured to be operatively coupled to the target nerve of the patient.

11. The system of claim 1 , wherein the at least one controller is configured to determine the therapy- specific indicator indicative of the effect of the at least one first electrical stimulation on respiration that comprises central sleep apnea events.

12. The system of claim 1, wherein providing the at least one first electrical stimulation causes the diaphragm of the patient to contract.

13. The system of claim 1, wherein one or more leads of the at least one lead are configured to be implanted in a lumen of the patient.

14. The system of claim 13, wherein the lumen comprises at least one of the right brachiocephalic vein, the left brachiocephalic vein, the superior vena cava, the right internal jugular vein, the left internal jugular vein, the left subclavian vein, the right subclavian vein, the right pericardiophrenic vein, or the left pericardiophrenic vein.

15. The system of claim 1, wherein the respiratory information is indicative of a breathing rate of the patient.

16. The system of claim 15, wherein the at least one first sensor comprises a transthoracic impedance sensor.

17. The system of any of claims 15 and 16, wherein the respiratory information is indicative of a lung volume of the patient.

18. The system of claim 1, wherein the non-respiratory information is indicative of movement of the patient.

19. The system of claim 18, wherein the movement of the patient is indicative of movement of the chest of the patient caused by the patient breathing.

20. The system of claim 18, wherein the movement of the patient is indicative of a change in a position of the patient.

21. The system of claim 20, wherein the position of the patient comprises one of a side position, a supine position, a prone position, or a vertical position.

22. The system of claim 18, wherein the at least one second sensor comprises at least one accelerometer.

23. The system of claim 22, wherein the at least one accelerometer is implanted in the patient.

24. The system of claim 23, wherein the at least one accelerometer is disposed on the at least one electrical-pulse generator.

25. The system of claim 22, wherein the at least one accelerometer comprises a first accelerometer external to the patient.

26. The system of claim 25, wherein the at least one accelerometer comprises a second accelerometer implanted in the patient.

27. The system of any of claims 18-26, wherein the non-respiratory information is further indicative of a heart rate of the patient.

28. The system of claim 27, wherein the at least one second sensor comprises an optical sensor.

29. The system of claim 28, wherein the optical sensor comprises a pulse oximeter.

30. The system of any of claims 18-29, wherein the at least one second sensor is disposed on one or more leads and is configured to sense electrical activity of the heart of the patient.

31. The system of claim 30, wherein the non-respiratory information is indicative of a sleep stage of the patient.

32. The system of claim 31, wherein the at least one second sensor comprises at least one of an accelerometer or a heart-rate sensor.

33. The system of claim 32, wherein the at least one controller is configured to determine, based on the non-respiratory information, the sleep stage of the patient.

34. The system of claim 33, wherein the sleep stage comprises one of light sleep, deep sleep, and rapid-eye-movement sleep.

35. The system of claim 1, wherein the non-respiratory information is indicative of a heart rate of the patient.

36. The system of claim 35, wherein the at least one second sensor comprises an optical sensor.

37. The system of claim 36, wherein the optical sensor comprises a pulse oximeter.

38. The system of claim 35, wherein the at least one second sensor comprises one or more electrodes configured to sense electrical activity of the heart of the patient.

39. The system of claim 1, wherein the non-respiratory information is indicative of a sleep stage of the patient.

40. The system of claim 39, wherein the at least one second sensor comprises at least one of an accelerometer or a heart-rate sensor.

41. The system of claim 39, wherein the at least one controller is configured to determine, based on the non-respiratory information, the sleep stage of the patient.

42. The system of claim 41, wherein the sleep stage comprises one of light sleep, deep sleep, and rapid-eye-movement sleep.

43. The system of claim 41, wherein the sleep stage of the patient comprises the patient being awake.

44. The system of claim 1, wherein the at least one controller is further configured to: determine, based on the non-respiratory information, that the patient is rolling responsive to providing the at least one first electrical stimulation; and modify the at least one stimulation parameter based on determining that the patient is rolling.

45. The system of claim 44, wherein modifying the at least one stimulation parameter comprises decreasing a current of the at least one first electrical stimulation.

46. The system of claim 44, wherein the at least one controller is further configured to stop providing stimulation to the at least one lead responsive to determining that the patient is rolling.

47. The system of claim 46, wherein the at least one controller is further configured to resume providing stimulation to the at least one lead responsive to determining that the patient is stationary.

48. The system of claim 47, wherein the at least one second sensor comprises an accelerometer and the non-respiratory information is indicative of movement of the patient.

49. The system of claim 44, wherein determining that the patient is rolling responsive to providing the at least one first electrical stimulation comprises: determining that the patient is moving based on the non-respiratory information; determining whether the patient began moving within a threshold period of time after providing the at least one first electrical stimulation; anddetermining that the patient moving is caused by the at least one first electrical stimulation responsive to determining that the patient began moving within the threshold period of time.

50. The system of claim 1, wherein the one or more stimulation parameters comprise at least one of a current level of the at least one first electrical stimulation, a pulse duration of the at least one first electrical stimulation, a number of pulses of the at least one first electrical stimulation, a frequency of pulses of the at least one first electrical stimulation, or a respective current level of each pulse of a plurality of pulses of the at least one first electrical stimulation.

51. The system of claim 50, wherein the at least one controller is configured to provide the at least one first electrical stimulation and the at least one second electrical stimulation in a synchronous mode, and modify the pulse duration of the at least one first electrical stimulation.

52. The system of claim 1, wherein the respiratory information is indicative of a lung volume of the patient.

53. The system of claim 52, wherein the at least one first sensor comprises a transthoracic impedance sensor.

54. The system of claim 1, wherein the at least one first sensor comprises one or more of an accelerometer, a pressure sensor, a transthoracic impedance sensor, a heart-rate sensor, or an electromyography sensor.

55. The system of claim 1, wherein the at least one second sensor comprises one or more of an accelerometer, a pressure sensor, a transthoracic impedance sensor, a heart-rate sensor, or an electromyography sensor.

56. The system of claim 1, wherein the therapy-specific indicator is indicative of entrainment of the respiration of the patient to the at least one first electrical stimulation.

57. The system of claim 56, wherein the at least one controller is configured to provide the at least one first electrical stimulation and the at least one second electrical stimulation in an asynchronous mode, and modify a current of the at least one electrical stimulation based on the therapy- specific indicator indicative of entrainment.

58. The system of claim 1, wherein the patient-specific indicator is indicative of at least one of a position of the patient, movement of the patient, a heart rate of the patient, a change in the heart rate of the patient, a sleep stage of the patient, or a change in the sleep change of the patient, in response to the at least one first electrical stimulation.

59. The system of claim 1, wherein the at least one second sensor comprises a peripheral arterial tone sensor.

60. The system of claim 1, wherein the at least one controller is configured to receive the non-respiratory information outside of a therapy window for the patient.

61. The system of claim 1, wherein the target nerve comprises a hypoglossal nerve.

62. The system of claim 61, wherein the at least one controller is configured to determine the therapy- specific indicator indicative of the effect of the at least on first electrical stimulation on respiration that comprises obstructive sleep apnea events.

63. The system of claim 1, wherein the at least one controller is configured to modify, based on at least one therapy-specific indicator and at least one patient-specific indicator, at least one stimulation parameter of the at least one electrical stimulation.

64. The system of claim 1, wherein the at least one controller is configured to modify, based on at least two therapy- specific indicators, at least one stimulation parameter of the at least one electrical stimulation.

65. The system of claim 1, wherein the at least one controller is configured to modify, based on at least two patient- specific indicators, at least one stimulation parameter of the at least one electrical stimulation.

66. The system of claim 1, wherein the at least one controller is configured to automatically modify the at least one stimulation parameter of the at least one electrical stimulation in a closed- loop operation mode based on at least one of the therapy-specific indicator or the patient-specific indicator.

67. The system of claim 1, wherein the at least one controller comprises at least one processor, at least one memory, and power adjusting circuitry.

68. The system of claim 1, wherein the at least one controller is configured to modify the at least one stimulation parameter of the at least one electrical stimulation to increase the intensity of the at least one electrical stimulation to the phrenic nerve based on the at least one therapyspecific indicator comprising at least one of flow sensor data indicative of low flow relative to a normal patient, acoustic sensor data indicative of low noise relative to a normal patient, vibration sensor data indicative of low vibration relative to a normal patient, transthoracic impedance sensor data indicative of low transthoracic impedance relative to a normal patient, heart rate sensor data indicative of a variable heart rate relative to a normal patient, electromyography (EMG) sensor data indicative of variable or low EMG signals from the diaphragm relative to a normal patient, or diaphragm motion sensor data indicative of low diaphragm motion relative to a normal patient.

69. The system of claim 1, wherein the target nerve comprises a hypoglossal nerve, and wherein the at least one controller is configured to modify the at least one stimulation parameter of the at least one electrical stimulation to increase the intensity of the at least one electrical stimulation to the hypoglossal nerve based on the at least one therapy-specific indicator comprising at least one of flow sensor data indicative of low flow relative to a normal patient, acoustic sensor data indicative of high noise relative to a normal patient, vibration sensor dataindicative of high vibration relative to a normal patient, pressure sensor data indicative high pressure relative to a normal patient, transthoracic impedance sensor data indicative of high transthoracic impedance relative to a normal patient, heart rate sensor data indicative of a variable heart rate relative to a normal patient, peripheral arterial tone sensor data indicative of variable arterial tone data relative to a normal patient, electromyography (EMG) sensor data indicative of variable EMG signals from the diaphragm relative to a normal patient, diaphragm motion sensor data indicative of high diaphragm motion relative to a normal patient, or chest and diaphragm motion sensor data indicative of an out-of-phase relationship between chest and diaphragm motion.

70. The system of claim 1, wherein the at least one controller is configured to modify the at least one stimulation parameter of the at least one electrical stimulation to increase the intensity of the at least one electrical stimulation to the phrenic nerve based on the at least one patientspecific indicator comprising at least one of sensed patient movement, patient touch or voice feedback, a patient tap on the chest of the patient, a change in sleep state, or a high roll frequency.

71. The system of claim 1, wherein the physiologic information comprises non-respiratory information.

72. The system of claim 1, wherein the at least one patient parameter comprises at least one second respiratory parameter of the patient.

73. A system for treating disordered breathing in a patient, the system comprising: at least one electrical-pulse generator comprising at least one controller and at least one power source, the at least one electrical-pulse generator being configured to generate at least one electrical stimulation; at least one lead configured to be coupled to the at least one electrical-pulse generator and being configured to be implanted in the patient to deliver the at least one electrical stimulation to a target nerve of the patient, the target nerve comprising a phrenic nerve;at least one first sensor configured to detect at least one first patient parameter comprising at least one respiratory parameter of the patient; and at least one second sensor configured to detect at least one second patient parameter comprising at least one non-respiratory parameter of the patient, the at least one controller being configured to provide, via the at least one lead, at least one first electrical stimulation having one or more stimulation parameters to the target nerve of the patient to treat disordered breathing in the patient, receive, from the at least one first sensor, respiratory information indicative of the at least one respiratory parameter of the patient, determine, based on the respiratory information, a therapy- specific indicator indicative of an effect of the at least one first electrical stimulation on respiration of the patient, receive, from the at least one second sensor, non-respiratory information indicative of the at least one non-respiratory parameter of the patient, determine, based on the non-respiratory information, a patient-specific indicator relating to at least one condition of the patient, modify, based on at least one of the therapy-specific indicator or the patientspecific indicator, at least one stimulation parameter of the electrical stimulation, and provide, via the at least one lead, at least one second electrical stimulation having the modified at least one stimulation parameter to treat the patient.

74. The system of claim 73, wherein the at least one controller is further configured to: receive patient-feedback information from the patient; and modify the at least one stimulation parameter based on the patient-feedback information.

75. The system of claim 74, wherein modifying the at least one stimulation parameter comprises modifying a current level of the at least one first electrical stimulation.

76. The system of claim 75, wherein modifying the current level of the at least one first electrical stimulation comprises decreasing the current level of the at least one first electrical stimulation.

77. The system of claim 73, wherein modifying the at least one stimulation parameter comprises modifying a current level of the at least one first electrical stimulation.

78. The system of claim 77, wherein modifying the current level of the at least one first electrical stimulation comprises increasing the current level of the at least one first electrical stimulation.

79. The system of claim 77, wherein modifying the current level of the at least one first electrical stimulation comprises decreasing the current level of the at least one first electrical stimulation.

80. The system of claim 73, wherein the at least one lead comprises one or more electrodes.

81. The system of claim 80, wherein one or more leads of the at least one lead are configured to be implanted in a lumen proximate the target nerve of the patient.

82. The system of claim 73, wherein the at least one lead comprises one or more nerve cuffs.

83. The system of claim 82, wherein at least one nerve cuff of the one or more nerve cuffs is configured to be operatively coupled to the target nerve of the patient.

84. The system of claim 73, wherein the at least one controller is configured to determine the therapy- specific indicator indicative of the effect of the at least one first electrical stimulation on respiration that comprises central sleep apnea events.

85. The system of claim 73, wherein providing the at least one first electrical stimulation causes the diaphragm of the patient to contract.

86. The system of claim 73, wherein one or more leads of the at least one lead are configured to be implanted in a lumen of the patient.

87. The system of claim 86, wherein the lumen comprises at least one of the right brachiocephalic vein, the left brachiocephalic vein, the superior vena cava, the right internal jugular vein, the left internal jugular vein, the left subclavian vein, the right subclavian vein, the right pericardiophrenic vein, or the left pericardiophrenic vein.

88. The system of claim 73, wherein the respiratory information is indicative of a breathing rate of the patient.

89. The system of claim 88, wherein the at least one first sensor comprises a transthoracic impedance sensor.

90. The system of any of claims 88 and 89, wherein the respiratory information is indicative of a lung volume of the patient.

91. The system of claim 73, wherein the non-respiratory information is indicative of movement of the patient.

92. The system of claim 91, wherein the movement of the patient is indicative of movement of the chest of the patient caused by the patient breathing.

93. The system of claim 91, wherein the movement of the patient is indicative of a change in a position of the patient.

94. The system of claim 93, wherein the position of the patient comprises one of a side position, a supine position, a prone position, or a vertical position.

95. The system of claim 91, wherein the at least one second sensor comprises at least one accelerometer.

96. The system of claim 95, wherein the at least one accelerometer is implanted in the patient.

97. The system of claim 96, wherein the at least one accelerometer is disposed on the at least one electrical-pulse generator.

98. The system of claim 95, wherein the at least one accelerometer comprises a first accelerometer external to the patient.

99. The system of claim 98, wherein the at least one accelerometer comprises a second accelerometer implanted in the patient.

100. The system of any of claims 91-99, wherein the non-respiratory information is further indicative of a heart rate of the patient.

101. The system of claim 100, wherein the at least one second sensor comprises an optical sensor.

102. The system of claim 101, wherein the optical sensor comprises a pulse oximeter.

103. The system of claim 102, wherein the at least one second sensor is disposed on one or more leads and is configured to sense electrical activity of the heart of the patient.

104. The system of any of claims 91-103, wherein the non-respiratory information is indicative of a sleep stage of the patient.

105. The system of claim 104, wherein the at least one second sensor comprises at least one of an accelerometer or a heart-rate sensor.

106. The system of claim 105, wherein the at least one controller is configured to determine, based on the non-respiratory information, the sleep stage of the patient.

107. The system of claim 106, wherein the sleep stage comprises one of light sleep, deep sleep, and rapid-eye-movement sleep.

108. The system of claim 73, wherein the non-respiratory information is indicative of a heart rate of the patient.

109. The system of claim 108, wherein the at least one second sensor comprises an optical sensor.

110. The system of claim 109, wherein the optical sensor comprises a pulse oximeter.

111. The system of claim 108, wherein the at least one second sensor is disposed on one or more leads and is configured to sense electrical activity of the heart of the patient.

112. The system of claim 73, wherein the non-respiratory information is indicative of a sleep stage of the patient.

113. The system of claim 112, wherein the at least one second sensor comprises at least one of an accelerometer or a heart-rate sensor.

114. The system of claim 112, wherein the at least one controller is configured to determine, based on the non-respiratory information, the sleep stage of the patient.

115. The system of claim 114, wherein the sleep stage comprises one of light sleep, deep sleep, and rapid-eye-movement sleep.

116. The system of claim 73, wherein the respiratory information and the non-respiratory information are indicative of an impact of the at least one first electrical stimulation on the patient breathing.

117. The system of claim 73, wherein the at least one controller is further configured to: determine, based on the non-respiratory information, that the patient is rolling responsive to providing the at least one first electrical stimulation; and modify the at least one stimulation parameter based on determining that the patient is rolling.

118. The system of claim 117, wherein modifying the at least one stimulation parameter comprises decreasing a current of the at least one first electrical stimulation.

119. The system of claim 117, wherein the at least one controller is further configured to stop providing stimulation to the at least one lead responsive to determining that the patient is rolling.

120. The system of claim 119, wherein the at least one controller is further configured to resume providing stimulation to the at least one lead responsive to determining that the patient is stationary.

121. The system of claim 120, wherein the at least one second sensor comprises an accelerometer and the non-respiratory information is indicative of movement of the patient.

122. The system of claim 117, wherein determining that the patient is rolling responsive to providing the at least one first electrical stimulation comprises: determining that the patient is moving based on the non-respiratory information; determining whether the patient began moving within a threshold period of time after providing the at least one first electrical stimulation; and determining that the patient moving is caused by the at least one first electrical stimulation responsive to determining that the patient began moving within the threshold period of time.

123. The system of claim 73, wherein the one or more stimulation parameters comprise at least one of a current level of the at least one first electrical stimulation, a pulse duration of the at least one first electrical stimulation, a number of pulses of the at least one first electrical stimulation, a frequency of pulses of the at least one first electrical stimulation, or a respective current level of each pulse of a plurality of pulses of the at least one first electrical stimulation.

124. The system of claim 123, wherein the at least one controller is configured to provide the at least one first electrical stimulation and the at least one second electrical stimulation in a synchronous mode, and modify the pulse duration of the at least one first electrical stimulation.

125. The system of claim 73, wherein the respiratory information is indicative of a lung volume of the patient.

126. The system of claim 125, wherein the at least one first sensor comprises a transthoracic impedance sensor.

127. The system of claim 73, wherein at least one of the at least one first sensor or the at least one second sensor comprises one or more of an accelerometer, a pressure sensor, a transthoracic impedance sensor, an optical sensor, a heart-rate sensor, or an electromyography sensor.

128. The system of claim 73, wherein the therapy-specific indicator is indicative of entrainment of the respiration of the patient to the at least one first electrical stimulation.

129. The system of claim 128, wherein the at least one controller is configured to provide the at least one first electrical stimulation and the at least one second electrical stimulation in an asynchronous mode, and modify a current of the at least one electrical stimulation based on the therapy- specific indicator indicative of entrainment.

130. The system of claim 73, wherein the patient- specific indicator is indicative of at least one of a position of the patient, movement of the patient, a heart rate of the patient, a change in the heart rate of the patient, a sleep stage of the patient, or a change in the sleep change of the patient, in response to the at least one first electrical stimulation.

131. The system of claim 73, wherein the respiratory information is indicative of a blood- oxygen level of the patient.

132. The system of claim 131, wherein the respiratory information is indicative of a peripheral oxygen saturation level of the patient.

133. The system of claim 132, wherein the at least one second sensor comprises a pulse oximeter.

134. The system of claim 73, wherein the respiratory information is indicative of sound produced by the patient breathing.

135. The system of claim 134, wherein the at least one first sensor comprises an acoustic sensor.

136. The system of claim 73, wherein the respiratory information is indicative of a lung volume of the patient, and wherein the at least one first sensor comprises a pressure sensor.

137. The system of claim 136, wherein the pressure sensor is implanted in the patient.

138. The system of claim 73, wherein the at least one first sensor comprises a near- infrared spectroscopy sensor.

139. The system of claim 73, wherein the at least one first sensor comprises at least one peripheral arterial tone sensor.

140. The system of claim 73, wherein the at least one first sensor comprises at least one flow sensor.

141. The system of claim 73, wherein the at least one first sensor comprises at least one pulse oximeter.

142. The system of claim 73, wherein the at least one first sensor comprises at least one acoustic sensor.

143. The system of claim 142, wherein the respiratory information is indicative of sound produced by the heart of the patient beating.

144. The system of claim 73, wherein the at least one controller is configured to receive the non-respiratory information outside of a therapy window for the patient.

145. The system of claim 73, wherein the target nerve comprises a hypoglossal nerve.

146. The system of claim 145, wherein the at least one controller is configured to determine the therapy-specific indicator indicative of the effect of the at least on first electrical stimulation on respiration that comprises obstructive sleep apnea events.

147. The system of claim 73, wherein the at least one controller is configured to modify, based on at least one therapy-specific indicator and at least one patient-specific indicator, at least one stimulation parameter of the at least one electrical stimulation.

148. The system of claim 73, wherein the at least one controller is configured to modify, based on at least two therapy- specific indicators, at least one stimulation parameter of the at least one electrical stimulation.

149. The system of claim 73, wherein the at least one controller is configured to modify, based on at least two patient- specific indicators, at least one stimulation parameter of the at least one electrical stimulation.

150. The system of claim 73, wherein the at least one controller is configured to automatically modify the at least one stimulation parameter of the at least one electrical stimulation in a closed- loop operation mode based on at least one of the therapy-specific indicator or the patient-specific indicator.

151. The system of claim 73, wherein the at least one controller comprises at least one processor, at least one memory, and power adjusting circuitry.

152. The system of claim 73, wherein the at least one controller is configured to modify the at least one stimulation parameter of the at least one electrical stimulation to increase the intensity of the at least one electrical stimulation to the phrenic nerve based on the at least one therapyspecific indicator comprising at least one of flow sensor data indicative of low flow relative to a normal patient, acoustic sensor data indicative of low noise relative to a normal patient, vibration sensor data indicative of low vibration relative to a normal patient, transthoracic impedance sensor data indicative of low transthoracic impedance relative to a normal patient, heart rate sensor data indicative of a variable heart rate relative to a normal patient, electromyography (EMG) sensor data indicative of variable or low EMG signals from the diaphragm relative to a normal patient, or diaphragm motion sensor data indicative of low diaphragm motion relative to a normal patient.

153. The system of claim 73, wherein the target nerve comprises a hypoglossal nerve, and wherein the at least one controller is configured to modify the at least one stimulation parameter of the at least one electrical stimulation to increase the intensity of the at least one electrical stimulation to the hypoglossal nerve based on the at least one therapy-specific indicator comprising at least one of flow sensor data indicative of low flow relative to a normal patient, acoustic sensor data indicative of high noise relative to a normal patient, vibration sensor data indicative of high vibration relative to a normal patient, pressure sensor data indicative highpressure relative to a normal patient, transthoracic impedance sensor data indicative of high transthoracic impedance relative to a normal patient, heart rate sensor data indicative of a variable heart rate relative to a normal patient, peripheral arterial tone sensor data indicative of variable arterial tone data relative to a normal patient, electromyography (EMG) sensor data indicative of variable EMG signals from the diaphragm relative to a normal patient, diaphragm motion sensor data indicative of high diaphragm motion relative to a normal patient, or chest and diaphragm motion sensor data indicative of an out-of-phase relationship between chest and diaphragm motion.

154. The system of claim 73, wherein the at least one controller is configured to modify the at least one stimulation parameter of the at least one electrical stimulation to increase the intensity of the at least one electrical stimulation to the phrenic nerve based on the at least one patientspecific indicator comprising at least one of sensed patient movement, patient touch or voice feedback, a patient tap on the chest of the patient, a change in sleep state, or a high roll frequency.

155. The system of claim 73, wherein the at least one first patient parameter comprises at least one second non-respiratory parameter of the patient.

156. The system of claim 73, wherein the at least one second patient parameter comprises at least one second respiratory parameter of the patient.

157. A system for treating disordered breathing in a patient, the system comprising: at least one electrical-pulse generator comprising at least one controller and at least one power source, the at least one electrical-pulse generator being configured to generate at least one electrical stimulation; at least one stimulation lead configured to be coupled to the at least one electrical-pulse generator and being configured to be implanted in the patient to deliver the at least one electrical stimulation to a target nerve of the patient, the target nerve comprising a phrenic nerve; at least one sensing lead comprising at least one first sensor and configured to detect at least one first patient parameter comprising a respiratory parameter of the patient; andat least one second sensor configured to detect at least one second patient parameter comprising a non-respiratory parameter of the patient, the at least one controller being configured to provide, via the at least one stimulation lead, at least one first electrical stimulation having one or more stimulation parameters to the target nerve of the patient to treat disordered breathing in the patient, receive, from the at least one sensing lead, respiratory information indicative of the at least one respiratory parameter of the patient, determine, based on the respiratory information, a therapy- specific indicator indicative of an effect of the at least one first electrical stimulation on respiration of the patient, receive, from the at least one second sensor, non-respiratory information indicative of the at least one non-respiratory parameter of the patient, determine, based on the non-respiratory information, a patient-specific indicator relating to at least one condition of the patient, modify, based on at least one of the therapy-specific indicator or the patientspecific indicator, at least one stimulation parameter of the at least one electrical stimulation, and provide, via the at least one stimulation lead, at least one second electrical stimulation having the modified at least one stimulation parameter to treat the patient.

158. The system of claim 157, wherein the at least one controller is further configured to: receive patient-feedback information from the patient; and modify the at least one stimulation parameter based on the patient-feedback information.

159. The system of claim 158, wherein modifying the at least one stimulation parameter comprises modifying a current level of the at least one first electrical stimulation.

160. The system of claim 159, wherein modifying the current level of the at least one first electrical stimulation comprises decreasing the current level of the at least one first electrical stimulation.

161. The system of claim 157, wherein modifying the at least one stimulation parameter comprises modifying a current level of the at least one first electrical stimulation.

162. The system of claim 161, wherein modifying the current level of the at least one first electrical stimulation comprises increasing the current level of the at least one first electrical stimulation.

163. The system of claim 161, wherein modifying the current level of the at least one first electrical stimulation comprises decreasing the current level of the at least one first electrical stimulation.

164. The system of claim 157, wherein each of the at least one sensing lead and the at least one stimulation lead comprises one or more electrodes.

165. The system of claim 164, wherein one or more leads of the at least one stimulation lead are configured to be implanted in a lumen proximate the target nerve of the patient.

166. The system of claim 157, wherein the at least one stimulation lead comprises one or more nerve cuffs.

167. The system of claim 166, wherein at least one nerve cuff of the one or more nerve cuffs is configured to be operatively coupled to the target nerve of the patient.

168. The system of claim 157, wherein the at least one controller is configured to determine the therapy-specific indicator indicative of the effect of the at least one first electrical stimulation on respiration that comprises central sleep apnea.

169. The system of claim 157, wherein providing the at least one first electrical stimulation causes the diaphragm of the patient to contract.

170. The system of claim 157, wherein one or more leads of the at least one stimulation lead are configured to be implanted in a lumen of the patient.

171. The system of claim 170, wherein the lumen comprises at least one of the right brachiocephalic vein, the left brachiocephalic vein, the superior vena cava, the right internal jugular vein, the left internal jugular vein, the left subclavian vein, the right subclavian vein, the right pericardiophrenic vein, or the left pericardiophrenic vein.

172. The system of claim 157, wherein the respiratory information is indicative of a breathing rate of the patient.

173. The system of claim 172, wherein the at least one first sensor comprises a transthoracic impedance sensor.

174. The system of any of claims 172 and 173, wherein the respiratory information is indicative of a lung volume of the patient.

175. The system of claim 157, wherein the non-respiratory information is indicative of movement of the patient.

176. The system of claim 175, wherein the movement of the patient is indicative of movement of the chest of the patient caused by the patient breathing.

177. The system of claim 175, wherein the movement of the patient is indicative of a change in a position of the patient.

178. The system of claim 177, wherein the position of the patient comprises one of a side position, a supine position, a prone position, or a vertical position.

179. The system of claim 175, wherein the at least one second sensor comprises at least one accelerometer.

180. The system of claim 179, wherein the at least one accelerometer is implanted in the patient.

181. The system of claim 180, wherein the at least one accelerometer is disposed on the at least one electrical-pulse generator.

182. The system of claim 179, wherein the at least one accelerometer comprises a first accelerometer external to the patient.

183. The system of claim 182, wherein the at least one accelerometer comprises a second accelerometer implanted in the patient.

184. The system of any of claims 175-183, wherein the non-respiratory information is further indicative of a heart rate of the patient.

185. The system of claim 184, wherein the at least one second sensor comprises an optical sensor.

186. The system of claim 185, wherein the optical sensor comprises a pulse oximeter.

187. The system of any of claims 175-186, wherein the at least one second sensor is disposed on one or more leads and is configured to sense electrical activity of the heart of the patient.

188. The system of claim 187, wherein the non-respiratory information is indicative of a sleep stage of the patient.

189. The system of claim 188, wherein the at least one second sensor comprises at least one of an accelerometer or a heart-rate sensor.

190. The system of claim 189, wherein the at least one controller is configured to determine, based on the non-respiratory information, the sleep stage of the patient.

191. The system of claim 190, wherein the sleep stage comprises one of light sleep, deep sleep, and rapid-eye-movement sleep.

192. The system of claim 157, wherein the non-respiratory information is indicative of a heart rate of the patient.

193. The system of claim 192, wherein the at least one second sensor comprises an optical sensor.

194. The system of claim 193, wherein the optical sensor comprises a pulse oximeter.

195. The system of claim 192, wherein the at least one second sensor is disposed on one or more leads and is configured to sense electrical activity of the heart of the patient.

196. The system of claim 157, wherein the non-respiratory information is indicative of a sleep stage of the patient.

197. The system of claim 196, wherein the at least one second sensor comprises at least one of an accelerometer or a heart-rate sensor.

198. The system of claim 196, wherein the at least one controller is configured to determine, based on the non-respiratory information, the sleep stage of the patient.

199. The system of claim 198, wherein the sleep stage comprises one of light sleep, deep sleep, and rapid-eye-movement sleep.

200. The system of claim 157, wherein the respiratory information and the non-respiratory information are indicative of an impact of the at least one first electrical stimulation on the patient breathing.

201. The system of claim 157, wherein the at least one controller is further configured to: determine, based on the non-respiratory information, that the patient is rolling responsive to providing the at least one first electrical stimulation; and modify the at least one stimulation parameter based on determining that the patient is rolling.

202. The system of claim 201, wherein modifying the at least one stimulation parameter comprises decreasing a current of the at least one first electrical stimulation.

203. The system of claim 201, wherein the at least one controller is further configured to stop providing stimulation to the at least one lead responsive to determining that the patient is rolling.

204. The system of claim 203, wherein the at least one controller is further configured to resume providing stimulation to the at least one lead responsive to determining that the patient is stationary.

205. The system of claim 204, wherein the at least one second sensor comprises an accelerometer and the non-respiratory information is indicative of movement of the patient.

206. The system of claim 201, wherein determining that the patient is rolling responsive to providing the at least one first electrical stimulation comprises: determining that the patient is moving based on the non-respiratory information; determining whether the patient began moving within a threshold period of time after providing the at least one first electrical stimulation; and determining that the patient moving is caused by the at least one first electrical stimulation responsive to determining that the patient began moving within the threshold period of time.

207. The system of claim 157, wherein the one or more stimulation parameters comprise at least one of a current level of the at least one first electrical stimulation, a pulse duration of the at least one first electrical stimulation, a number of pulses of the at least one first electrical stimulation, a frequency of pulses of the at least one first electrical stimulation, or a respective current level of each pulse of a plurality of pulses of the at least one first electrical stimulation.

208. The system of claim 207, wherein the at least one controller is configured to provide the at least one first electrical stimulation and the at least one second electrical stimulation in a synchronous mode, and modify the pulse duration of the at least one first electrical stimulation.

209. The system of claim 157, wherein the respiratory information is indicative of a lung volume of the patient.

210. The system of claim 209, wherein the at least one first sensor comprises a transthoracic impedance sensor.

211. The system of claim 157, wherein the at least one second sensor comprises two or more of an accelerometer, a pressure sensor, a transthoracic impedance sensor, an optical sensor, or a heart-rate sensor.

212. The system of claim 157, wherein the therapy-specific indicator is indicative of entrainment of the respiration of the patient to the at least one first electrical stimulation.

213. The system of claim 212, wherein the at least one controller is configured to provide the at least one first electrical stimulation and the at least one second electrical stimulation in an asynchronous mode, and modify a current of the electrical stimulation based on the therapy-specific indicator indicative of entrainment.

214. The system of claim 157, wherein the patient- specific indicator is indicative of at least one of a position of the patient, movement of the patient, a heart rate of the patient, a change in the heart rate of the patient, a sleep stage of the patient, or a change in the sleep change of the patient, in response to the at least one first electrical stimulation.

215. The system of claim 157, wherein the at least one second sensor comprises a nearinfrared spectroscopy sensor.

216. The system of claim 157, wherein the at least one controller is configured to receive the non-respiratory information outside of a therapy window for the patient.

217. The system of claim 157, wherein the target nerve comprises a hypoglossal nerve.

218. The system of claim 217, wherein the at least one controller is configured to determine the therapy-specific indicator indicative of the effect of the at least on first electrical stimulation on respiration that comprises obstructive sleep apnea events.

219. The system of claim 157, wherein the at least one controller is configured to modify, based on at least one therapy-specific indicator and at least one patient-specific indicator, at least one stimulation parameter of the at least one electrical stimulation.

220. The system of claim 157, wherein the at least one controller is configured to modify, based on at least two therapy-specific indicators, at least one stimulation parameter of the at least one electrical stimulation.

221. The system of claim 157, wherein the at least one controller is configured to modify, based on at least two patient- specific indicators, at least one stimulation parameter of the at least one electrical stimulation.

222. The system of claim 157, wherein the at least one controller is configured to automatically modify the at least one stimulation parameter of the at least one electricalstimulation in a closed-loop operation mode based on at least one of the therapy- specific indicator or the patient- specific indicator.

223. The system of claim 157, wherein the at least one controller comprises at least one processor, at least one memory, and power adjusting circuitry.

224. The system of claim 157, wherein the at least one controller is configured to modify the at least one stimulation parameter of the at least one electrical stimulation to increase the intensity of the at least one electrical stimulation to the phrenic nerve based on the at least one therapy- specific indicator comprising at least one of flow sensor data indicative of low flow relative to a normal patient, acoustic sensor data indicative of low noise relative to a normal patient, vibration sensor data indicative of low vibration relative to a normal patient, transthoracic impedance sensor data indicative of low transthoracic impedance relative to a normal patient, heart rate sensor data indicative of a variable heart rate relative to a normal patient, electromyography (EMG) sensor data indicative of variable or low EMG signals from the diaphragm relative to a normal patient, or diaphragm motion sensor data indicative of low diaphragm motion relative to a normal patient.

225. The system of claim 157, wherein the target nerve comprises a hypoglossal nerve, and wherein the at least one controller is configured to modify the at least one stimulation parameter of the at least one electrical stimulation to increase the intensity of the at least one electrical stimulation to the hypoglossal nerve based on the at least one therapy-specific indicator comprising at least one of flow sensor data indicative of low flow relative to a normal patient, acoustic sensor data indicative of high noise relative to a normal patient, vibration sensor data indicative of high vibration relative to a normal patient, pressure sensor data indicative high pressure relative to a normal patient, transthoracic impedance sensor data indicative of high transthoracic impedance relative to a normal patient, heart rate sensor data indicative of a variable heart rate relative to a normal patient, peripheral arterial tone sensor data indicative of variable arterial tone data relative to a normal patient, electromyography (EMG) sensor data indicative of variable EMG signals from the diaphragm relative to a normal patient, diaphragm motion sensor data indicative of high diaphragm motion relative to a normal patient, or chest anddiaphragm motion sensor data indicative of an out-of-phase relationship between chest and diaphragm motion.

226. The system of claim 157, wherein the at least one controller is configured to modify the at least one stimulation parameter of the at least one electrical stimulation to increase the intensity of the at least one electrical stimulation to the phrenic nerve based on the at least one patient-specific indicator comprising at least one of sensed patient movement, patient touch or voice feedback, a patient tap on the chest of the patient, a change in sleep state, or a high roll frequency.

227. The system of claim 157, wherein the at least one first sensor comprises one or more of an accelerometer, a pressure sensor, a transthoracic impedance sensor, a heart-rate sensor, or an electromyography sensor.

228. The system of claim 157, wherein the at least one second sensor comprises one or more of an accelerometer, a pressure sensor, a transthoracic impedance sensor, a heart-rate sensor, or an electromyography sensor.

229. The system of claim 157, wherein the at least one first patient parameter comprises at least one non-respiratory parameter of the patient.

230. The system of claim 157, wherein the at least one second patient parameter comprises at least one respiratory parameter of the patient.

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