System for monitoring physiological parameters

Abstract

A system including sensing circuitry and processing circuitry. The processing circuitry is configured to: cause the sensing circuitry to sense a first plurality of physiological parameter values over a first time period in a first sensing mode; compare each of the first plurality of physiological parameter values against a threshold parameter value; in response to determining that at least a threshold amount of the first plurality of physiological parameter values satisfies the threshold parameter value, cause the sensing circuitry to sense a second plurality of physiological parameter values over a second time period in the first sensing mode, and in response to determining that less than the threshold amount of the first plurality of physiological parameter values satisfies the threshold parameter value, cause the sensing circuitry to sense the second plurality of physiological parameter values over the second time period in a second sensing mode.

Description

SYSTEM FOR MONITORING PHYSIOLOGICAL PARAMETERS

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 613,460, filed December 21, 2023, the entire content of which is incorporated herein by reference.TECHNICAL FIELD

[0002] The disclosure relates generally to medical systems and, more particularly, medical systems configured to monitor patient activity for changes in patient health.BACKGROUND

[0003] Some types of medical systems may monitor one or more physiological parameters of a patient. The medical system may detect signals associated with the one or more physiological parameters and may determine values for the physiological parameters based on the detected signals. The determined values may be used to detect changes in medical conditions, to evaluate efficacy of a medical therapy, or to generally evaluate patient health. In some examples, the medical system may include one or more of an implantable medical device or a wearable device to collect the data.SUMMARY

[0004] A medical system may sense one or more physiological parameters of a patient to detect changes in medical condition(s) of the patient, to evaluate the efficacy of medical therapy (e.g., medication) on the patient, and / or to generally evaluate health of the patient. The medical system may sense the one or more physiological parameters via one or more medical devices, e.g., one or more implantable medical devices (IMDs) and / or wearable devices. The medical system may sense signals from the patient via sensor(s) coupled to the one or more medical devices and determine values for physiological parameters based at least in part on the sensed signals. Physiological parameters may include, but are not limited to, blood pressure levels, blood oxygen saturation levels, blood glucose levels, cardiac signals (e.g., electrocardiogram (EGM) signals), or the like.

[0005] This disclosure describes devices, systems, and methods for selectively sensing signals via different sensing modes based on sensed physiological parameter values (e.g., based on determined physiological parameter values corresponding to the sensed signals).The medical system described in this disclosure may sense one or more physiological parameters across multiple time periods. Each sensing mode may define sensing parameters for the medical system within each time window of a time period such as, but is not limited to, a number of detection windows and / or detection occurrences within each time window. In such examples, the medical system may sense physiological parameter values across multiple time windows within each time period, wherein the medical system senses the physiological parameters during one or more detection occurrences and / or detection windows within each time window. The medical system may sense signals during a first number of detection windows and / or for a first number of times during a time window in accordance with a first sensing mode and detect signals during a second number of detection windows and / or for a second number of times during the time window in accordance with a second sensing mode. Thus, the medical system may sense signals from the patient at a changed frequency, e.g., an increased frequency, within time windows of a time period in one sensing mode as compared to another sensing mode. For example, the medical system may sense signals once per each time window of a time period in one sensing mode and more than once per each time window of the time period (e.g., four times per time window) in another sensing mode.

[0006] The example techniques described herein may cause the medical system to switch between sensing modes based on sensed physiological parameter values from one or more prior time periods. In some examples, the medical system determines and / or receives information indicating that the patient is experiencing a medical condition, is experiencing a change in a medical condition, and / or is undergoing a change in medical therapy based at least in part on physiological parameter values determined based on signals sensed during one or more prior time periods. In such examples, the medical system may responsively switch to a sensing mode with an increased sensing frequency, e.g., to increase the monitoring of physiological parameters within each time window of a current time period. In some examples, the medical system may determine and / or receive information indicating that the patient is no longer experiencing a medical condition and / or has experienced a threshold degree of positive change in the medical condition and may responsively switch to a sensing mode with a decreased sensing frequency in response.

[0007] The techniques described herein may improve the sensing and monitoring efficiency of the medical system by causing the medical system to switch between different sensing modes. The medical system may increase the sensing frequency under a first sensing mode to provide higher resolution physiological parameter values which may better capture changes in physiological parameter values when the patient is experiencing conditions, such as when the patient is experiencing a medical condition, a change in a medical condition, and / or a change in medical therapy. The medical system may decrease the sensing frequency when patient condition does not require increased monitoring (e.g., when the patient condition is improving, or when the patient is not experiencing a medical condition) to reduce unnecessary power consumption and data transmission while continuing to monitor the patient.

[0008] In some examples, this disclosure describes a system comprising: sensing circuitry configured to sense physiological parameter values from a patient via one or more sensors; and processing circuitry coupled to the sensing circuitry, the processing circuitry being configured to: cause the sensing circuitry to sense a first plurality of physiological parameter values over a first time period in a first sensing mode; receive the first plurality of physiological parameter values from the sensing circuitry; compare each physiological parameter value of the first plurality of physiological parameter values against a threshold parameter value; in response to determining that at least a threshold amount of physiological parameter values of the first plurality of physiological parameter values satisfies the threshold parameter value, cause the sensing circuitry to sense a second plurality of physiological parameter values over a second time period in the first sensing mode, and in response to determining that less than the threshold amount of physiological parameter values of the first plurality of physiological parameter values satisfy the threshold parameter value, cause the sensing circuitry to sense the second plurality of physiological parameter values over the second time period in a second sensing mode, wherein the second sensing mode is different from the first sensing mode.

[0009] In some examples, this disclosure describes a method for operating a medical system to sense physiological parameter values from a patient, the method comprising: causing, by processing circuitry of the medical system, sensing circuitry of the medical system to sense a first plurality of physiological parameter values from the patient over a first time period via one or more sensors coupled to the sensing circuitry; comparing, bythe processing circuitry, each physiological parameter value of the first plurality of physiological parameter values against a threshold parameter value; in response to determining that at least a threshold amount of physiological parameter values of the first plurality of physiological parameter values satisfy the threshold parameter value, causing, by the processing circuitry, the sensing circuitry to sense a second plurality of physiological parameter values over a second time period in the first sensing mode; and in response to determining that less than the threshold amount of physiological parameter values of the first plurality of physiological parameter values satisfy the threshold parameter value, causing, by the processing circuitry, the sensing circuitry to sense the second plurality of physiological parameter values over the second time period in a second sensing mode, wherein the second sensing mode is different from the first sensing mode.

[0010] In some examples, this disclosure describes a computer-readable medium comprising instructions that, when executed, causes processing circuitry of a medical system to: cause sensing circuitry of the medical system to sense a first plurality of physiological parameter values from the patient over a first time period via one or more sensors coupled to the sensing circuitry; compare each physiological parameter value of the first plurality of physiological parameter values against a threshold parameter value; in response to determining that at least a threshold amount of physiological parameter values of the first plurality of physiological parameter values satisfy the threshold parameter value, cause the sensing circuitry to sense a second plurality of physiological parameter values over a second time period in the first sensing mode; and in response to determining that less than the threshold amount of physiological parameter values of the first plurality of physiological parameter values satisfy the threshold parameter value, cause the sensing circuitry to sense the second plurality of physiological parameter values over the second time period in a second sensing mode, wherein the second sensing mode is different from the first sensing mode.

[0011] In some examples, this disclosure describes a system comprising: sensing circuitry configured to sense physiological parameter values from a patient via one or more sensors; and processing circuitry coupled to the sensing circuitry, the processing circuitry being configured to: cause the sensing circuitry to sense physiological parameter values over a first time period at a first frequency across the first time period; compare each sensed physiological parameter value over the first time period against a thresholdparameter value; in response to determining that at least a threshold amount of sensed physiological parameter values over the first time period satisfies the threshold parameter value, cause the sensing circuitry to sense physiological parameter values over a second time period at the first frequency, and in response to determining that less than the threshold amount of sensed physiological parameter values over the first period satisfy the threshold parameter value, cause the sensing circuitry to sense physiological parameter values over the second time period at a second frequency within the second time period.

[0012] The summary is intended to provide an overview of the subject matter described in this disclosure. It is not intended to provide an exclusive or exhaustive explanation of the systems, device, and methods described in detail within the accompanying drawings and description below. Further details of one or more examples of this disclosure are set forth in the accompanying drawings and in the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 illustrates an example medical system in conjunction with a patient, in accordance with one or more examples of the present disclosure.

[0014] FIG. 2A is a perspective drawing illustrating an implantable medical device (IMD) of FIG. 1.

[0015] FIG. 2B is a perspective drawing illustrating another IMD of FIG. 1.

[0016] FIG. 3 is a block diagram illustrating an example configuration of the example IMD of FIG. 1.

[0017] FIG. 4 is a block diagram illustrating an example configuration of a computing device that operates in accordance with one or more techniques of the present disclosure.

[0018] FIG. 5 is a block diagram illustrating an example configuration of a health monitoring system that operates in accordance with one or more techniques of the present disclosure.

[0019] FIG. 6 is a graph illustrating example sensed physiological parameter values over time.

[0020] FIG. 7 is a flowchart illustrating an example process of monitoring one or more physiological parameters.

[0021] FIG. 8 is a flowchart illustrating another example process of monitoring one or more physiological parameters.

[0022] Like reference characters denote like elements throughout the description and figures.DETAILED DESCRIPTION

[0023] A medical system may be configured to monitor one or more physiological parameters of a patient to monitor a condition of the patient. For example, the medical system may, based on the one or more physiological parameters, evaluate whether the patient is experiencing a medical condition, whether the patient is experiencing a change in the medical conditions, whether there is a change in patient condition in response to a medical therapy and / or a change in medical one or more medical therapies, or the like. Physiological parameters may include, but are not limited to, blood pressure level, blood glucose level, blood oxygen saturation level, cardiac signals (e.g., EGM signals, heart rate measurements), neurological signals, tissue impedance, or the like. The medical system may sense signals from the patient (e.g., via one or more sensors coupled to a medical device) and determine values for physiological parameter(s) based on the sensed signals. The medical device may include one or more IMDs and / or external medical devices (e.g., wearable devices).

[0024] In some examples, physiological parameter values may vary over time (e.g., over a time window). For example, a blood pressure level of the patient may vary over the course of 24 hours. In such examples, when the medical system senses signals from the patient at a single instance and / or during a single detection window for each time window (e.g., one instance and / or detection window per 24 hours), the sensed signals may not be continuous and / or may not be representative of the physiological parameter values over the entire duration of the time window and / or may not account for variations in the physiological parameter values over time. The medical system may take multiple measurements over the course of the time window (e.g., multiple instances and / or detection windows throughout the time window) to monitor the changes in the physiological parameters throughout the time window and / or to account for the variations in the physiological parameter values over time. The increase in the number of measurements taken by medical system may increase the resolution of the data used tomonitor the changes in the physiological parameters. The increased data resolution may facilitate improved diagnosis of the cause of changes in physiological parameter and facilitate improved and / or earlier treatment of the patient. In some examples, where the medical device includes one or more IMDs, increasing the sensing frequency of the signals may increase the power consumption by the IMD, which may reduce the overall lifespan of the IMD and more frequency replacement and / or maintenance of the IMD compared to an identical IMD configured to sensed signals at a reduced sensing frequency.

[0025] FIG. 1 illustrates an example medical system 100 (e.g., “system 100”) including an IMD 104 in conjunction with a patient 102, in accordance with one or more examples of the present disclosure. IMD 104 is configured for continuous, long-term monitoring of patient 102. IMD 104 is configured to sense signals corresponding to one or more physiological parameters from patient 102. Continuous monitoring and / or sensing by IMD 104 may include monitoring and / or sensing on a triggered or periodic basis, without requiring user or clinician intervention.

[0026] IMD 104 may include an implantable cardiac monitor (ICM), implantable pacemaker, implantable cardioverter, or other implantable monitoring device. In some examples, IMD 104 includes a Reveal LINQ™or LINQ II™ ICM, available from Medtronic, Inc., of Minneapolis, Minnesota, which may be inserted subcutaneously. Such IMDs may facilitate relatively longer-term and continuous monitoring of patients during normal daily activities and may periodically transmit collected data to a remote patient monitoring system, such as the Medtronic Carelink™ Network.

[0027] IMD 104 may determine values of physiological parameters of patient 102 based on physiological signals sensed by sensors on, within, or coupled to IMD 104. Physiological parameters may include, but are not limited to, a posture of patient 102, acceleration of the body (e.g., of the torso) of patient 102, a g-force on patient 102, a heart rate of patient 102, a respiration rate of patient 102, a stress hormone level of patient 102, a body temperature of patient 102, a glucose level of patient 102, a blood pressure of patient 102, electroencephalogram (EEG) signals of patient 102, change in electrocardiogram (ECG) morphology of patient 102, change in electrogram (EGM) morphology of patient 102, impedance between two or more locations on patient 102, a blood oxygen saturation of patient 102, or a rate of change of a physiological parameter (e.g., a rate of change in heart rate, body temperature, respiration rate, and / or bloodoxygen saturation). IMD 104 may determine physiological parameter values for a time period (e.g., for a month) based on determined physiological parameter values of each of a plurality of time windows (e.g., each 24-hour time window) constituting the time period.

[0028] IMD 104 may sense signals from patient 102 based on a selected sensing mode. Each sensing mode may include values for one or more sensing parameters. Sensing parameters may include, but are not limited to, sensing sensitivity and / or a sensing frequency. Sensing frequency may represent a frequency at which IMD 104 senses signals from patient 102 for each time window of a time period. Sensing frequency may be defined as a number of occurrences per time window and / or a number of detection windows per time window. Different sensing modes may include different values for the sensing parameters. For example, IMD 104 may sense signals at a first sensing frequency based on a first sensing mode and sense signals at a second sensing frequency based on a second sensing mode, wherein the second sensing frequency is different from (e.g., greater than) the first sensing frequency.

[0029] IMD 104 may compare physiological parameter values for a prior time period against threshold conditions stored in IMD 104 and may determine a sensing mode based on the comparison. The threshold condition may include a threshold parameter value, a threshold amount, and / or a threshold percentage. If the physiological parameter values satisfy the threshold conditions (e.g., if at least a threshold amount or a threshold percentage of the physiological parameter values satisfies the threshold parameter value), IMD 104 may sense signals in a first sensing mode. If the physiological parameter values do not satisfy the threshold conditions, IMD 104 may sense signals in a second sensing mode, e.g., wherein the sensing frequency of the second sensing mode is different (e.g., greater than, less than) the sensing frequency of the first sensing mode. In some examples, IMD 104 is configured to switch between two different sensing modes based on the sensed physiological parameter values. In some examples, IMD 104 is configured to switch between three or more different sensing modes based on the sensed physiological parameter values.

[0030] IMD 104 may select a sensing mode to increase the sensing frequency in response to a determination that the physiological parameter values do not satisfy the threshold condition, e.g., that less than the threshold amount or threshold percentage of sensed physiological parameter values satisfy the threshold parameter value (e.g., is lessthan or equal to the threshold parameter value). The failure to satisfy the threshold condition may correspond to one or more of an onset of a medical condition, a change in a medical condition, effects of a medical therapy on patient 102, and / or changes in medical therapie(s) received by patient 102. For example, a determination that less than a threshold amount or the threshold percentage of sensed blood pressure values is less than or equal to a threshold blood pressure value may be indicative of an onset of hypertension, a change in a severity of existing hypertension, effects of an applied medical therapy (e.g., medication) on patient 102, and / or change in medical therapies (e.g., changes in type, dosage, and / or frequency of one or more medical therapies) received by patient 102. In such examples, patient 102 may be at an increased risk of experiencing adverse effects and / or the physiological parameters may need to be continuously monitored. IMD 104 may signals at an increased frequency to account for variations in the physiological parameter values over time (e.g., variations in blood pressure levels of patient 102 over time) and facilitate rapid identification of changes in physiological parameter values. IMD 104 may receive an indication that patient 102 has received a medical therapy and / or that one or more applied medical therapy has been changed via communications from one or more other computing devices of system 100 (e.g., from patient computing devices 106A, 106B, computing system 110, and / or clinician computing devices 128).

[0031] IMD 104 may select a sensing mode to maintain or reduce the sensing frequency in response to a determination that the physiological parameter values satisfy the threshold condition, e.g., that at least the threshold amount or threshold percentage of sensed physiological parameter values satisfy the threshold parameter value. In some examples, where IMD 104 was sensing signals at an increased sensing frequency, system 100 may select a different sensing mode to reduce the sensing frequency. In some examples, where IMD 104 was sensing signals at a baseline or reduced frequency, IMD 104 may select the same sensing mode to maintain the sensing frequency. IMD 104 may compare physiological parameter values for each time period against the threshold conditions and adjust sensing modes accordingly. The adjustment of sensing modes based on previously sensed physiological parameter values may allow for the increased sensing of signals if necessitated by the condition of patient 102, thereby increasing the accuracy and efficiency of the sensing functions performed by IMD 104 and / or allowing system 100 to obtain a continuous measurement and monitoring of one or more physiologicalparameters. The adjustment of sensing modes may also reduce sensing frequency, and thereby power consumption and data transmission volume, if the condition of patient 102 does not require increased monitoring, which may reduce power consumption by components of system 100 (e.g., by IMD 104), thereby increasing the operating lifespan of the components.

[0032] While FIG. 1 illustrates system 100 with IMD 104, other examples of system 100 may include one or more other IMDs and / or one or more external medical devices (e.g., wearable devices) instead of or in addition to IMD 104. The other IMDs and / or external medical devices may be configured to perform the processes attributed to IMD 104 as described herein.

[0033] In addition to IMD 104, system 100 includes one or more patient computing devices 106A, 106B (collectively referred to herein as “patient computing devices 106”). Patient computing devices 106 are configured for wireless communication with IMD 104. Patient computing devices 106 may retrieve physiological parameter data (e.g., physiological signals, physiological parameter values) from IMD 104. Patient computing devices 106 (e.g., patient computing device 106A) may be personal computing devices of patient 102. In some examples, patient computing devices 106 (e.g., patient computing device 106B) is worn by patient 102. Patient computing devices 106 may be any computing device configured for wireless communication with IMD 104, such as a desktop computer, a laptop computer, a tablet, a smartwatch, or a smartphone. Patient computing devices 106 may communicate with IMD 104 and with another patient computing device 106 according to a wireless communication protocol (e.g., according to Bluetooth® or Bluetooth® Low Energy (BLE) protocols). Wearable patient computing device 106B may include sensors (e.g., electrodes, oximeters, accelerometers) configured to sense physiological signals of patient 102 and may collect and store physiological parameter values based on the sensed physiological signals.

[0034] One or more of patient computing devices 106 may be configured to communicate with a variety of other devices or systems via a network 108 and patient computing devices 106. IMD 104 may transmit a notification to patient computing devices 106 in response to IMD 104 determining a physiological parameter value, in response to IMD 104 adjusting the sensing mode, or the like. The notification may indicate a current sensing mode of IMD 104, a last-sensed physiological parameter value, a time when IMD104 last sensed physiological parameter values, a next time when IMD 104 will sense physiological parameter values, and / or physiological parameter values information (e.g., average value, amount / percentage of values greater than a threshold condition) for a prior time period. Patient computing devices 106 may transmit, the notification and / or sensed physiological parameter values from IMD 104 to computing system 110 via network 108.

[0035] Computing system 110 may include processing circuitry 112 and memory 114. Processing circuitry 112 may include fixed function circuitry and / or programmable processing circuitry. Processing circuitry 112 may include any one or more of a microprocessor, a controller, a digital signal processor (DSP), graphics processing unit (GPU), tensor processing unit (TPU), an application specific integrated circuitry (ASIC), a field-programmable gate array (FPGA), or equivalent discrete or analog logic circuitry. In some examples, processing circuitry 112 may include multiple components, such as any combination of one or more microprocessors, one or more controllers, one or more DSPs, GPUs, TPUs, one or more ASIC, or one or more FPGAs, as well as other discrete or integrated logic circuitry, which may be physically located in one or more devices in one or more physical locations. Computing system 110 may be configured as a cloud computing system.

[0036] Processing circuitry 112 may be capable of processing instructions stored in memory 114. In some examples, memory 114 includes a computer-readable medium that includes instructions that, when executed by processing circuitry 112, cause computing system 110 and processing circuitry 112 to perform various functions attributed to them herein. In some examples, computing system 110 implements a health monitoring system (HMS) 116. As will be described in greater detail below, HMS 116 may monitor determined physiological parameter values from IMD 104 and determine the sensing mode for IMD 104 based on a comparison between determined physiological parameter values and a threshold condition stored in memory 114. Memory 114 may include any volatile, non-volatile, magnetic, optical, or electrical media, such as random-access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically - erasable programmable ROM (EEPROM), ferroelectric RAM (FRAM), dynamic randomaccess memory (DRAM), flash memory, or any other digital media.

[0037] Network 108 may include one or more computing devices, such as one or more non-edge switches, routers, hubs, gateways, security devices such as firewalls, intrusiondetection, and / or intrusion prevention devices, servers, cellular base stations and nodes, wireless access points, bridges, cable modems, application accelerators, or other network drives. Network 108 may include one or more networks administered by service providers and may thus form part of a large-scale public network infrastructure, e.g., the Internet. Network 108 may provide computing devices and systems, such as those illustrated in FIG. 1, access to the Internet, and may provide a communication framework that allows the computing devices and systems illustrated in FIG. 1 to communicate with each other but isolates some of the data flows from devices external to the private network for security purposes. In some examples, the communications between the computing devices and systems illustrated in FIG. 1 are encrypted.

[0038] IMD 104 may be configured to transmit physiological parameters values and / or the notifications to wireless access point 124 and / or patient computing devices 106. Wireless access point 124 and / or patient computing devices 106 may then communicate the retrieved data to computing system 110 via network 108.

[0039] In some examples, computing system 110 may be configured to provide a secured storage site for data that has been collected from IMD 104 and / or patient computing devices 106. Computing system 110 may include a database that stores medical-related and health-related data. For example, computing system 110 includes a cloud server or other remote server that stores data collected from IMD 104 and / or patient computing device 106. Computing system 110 may assembly data in webpages or other documents for viewing by trained clinicians, such as clinicians 130, via clinician computing devices 128. Clinicians 130 may include, but are not limited to, medical care providers and emergency medical services (EMS) providers. One or more aspects of the system 100 illustrated in FIG. 1 may be implemented with general network technology and functionality, which may be similar to that provided by the Medtronic CareLink® Network.

[0040] One or more of clinician computing devices 128 may be a tablet, smartphone, laptop computer, desktop computer, or other computing devices associated with one or more of clinicians 130, by which one or more clinicians 130 may program, receive notifications from, and / or interrogate IMD 104. For example, one or more clinicians 130 may access data collected by IMD 104 and / or patient computing device 106 (e.g., physiological parameter signals, physiological parameter values) through a cliniciancomputing device 128, such as when clinician computing device 128 receives the notification from IMD 104, patient computing devices 106, and / or computing system 110. Clinician 130 may determine, based on the data accessed through clinician computing device 128, whether patient 102 may require medical aid. The data and notification transmitted to clinician computing device 128 may facilitate the provision of medical aid by one or more clinicians 130 to patient 102.

[0041] Local network 122 may facilitate communication between patient computing devices 106 and other computing devices and systems (e.g., computing system 110, HMS 116) connected to network 108. Local network 112 may be configured with wireless technology, such as IEEE 802.11 wireless networks, IEEE 802.15 ZigBee networks, an ultra-wideband protocol, near-field communications, or the like. Local network 122 may include one or more wireless access points 124 configured to provide support for wireless communications throughout an environment encompassing local network 122. In some examples, patient computing devices 106 may communicate with network 108 (e.g., with HMS 116) via a cellular base station and / or cellular network.

[0042] System 100 may select sensing modes and cause IMD 104 to sense signals from patient 102 in accordance with the selected sensing mode. System 100 may receive sensed physiological parameter values corresponding to a prior time period from IMD 104 and compare the received physiological parameter values against threshold conditions stored in system 100 (e.g., in memory 114). In some examples, system 100 may select a different sensing mode to increase the sensing frequency in response to a failure to satisfy the threshold condition. In some examples, system 100 may select a same sensing mode or a different sensing mode to maintain or reduce the sensing frequency in response to a failure to satisfy the threshold condition. At the increased sensing frequency, sensing occurrences and / or detection windows may be evenly or randomly distributed across the duration of one time window or two or more time windows, e.g., to monitor for variations in physiological parameter values over time.

[0043] In some examples, system 100 determines that a threshold condition has been satisfied based on a determination that less than or equal to a threshold amount / percentage of physiological parameter values is less than or equal to a threshold parameter value (e.g., a threshold maximum blood pressure level). In some examples, system 100 determines that a threshold condition has been satisfied based on a determination that at least athreshold amount / percentage of physiological parameter values is greater than or equal to a threshold parameter value (e.g., a threshold minimum blood pressure level). The threshold parameter value may correspond to physiological parameter values corresponding to and / or indicative of an onset of a medical condition, an increase in severity of an existing medical condition, effects of the application of a medical therapy, and / or effects of a change in one or more medical therapies.

[0044] In some examples, system 100 may adjust one or more threshold conditions (e.g., one or more of the threshold parameter values, the threshold amount, or the threshold percentage) based on changes in the sensed physiological parameter values over time. The changes in the sensed physiological parameter values over time may be based on, but are not limited to, changes in physiology of patient 102, changes in disease state, or the like.

[0045] In some examples, system 100 may temporarily switch sensing modes (e.g., for at least one time period) independent of the comparison between the physiological parameter values and the threshold conditions. System 100 may temporarily switch to a sensing mode with an increased sensing frequency and cause IMD 104 to sense signals based on the temporary sensing mode, e.g., to validate the determinations made by system 100 regarding whether the physiological parameter values for prior time periods satisfy the threshold conditions. System 100 may switch to the temporary sensing mode after system 100 determines that the physiological parameter values satisfy the threshold conditions for at least a threshold number of consecutive times and / or by randomly assigning one or more future time periods to be sensed under the temporary sensing mode.

[0046] FIG. 2A is a perspective drawing illustrating an implantable medical device (IMD) 104 A, which may be an example configuration of IMD 104 of FIG. 1. In the example shown in FIG. 2 A, IMD 104 A may be embodied as a monitoring device having housing 202, proximal electrode 206A and distal electrode 206B. Housing 202 may further comprise a first major surface 204, a second major surface 208, a proximal end 210, and a distal end 212. Housing 202 encloses electronic circuitry located inside IMD 104 A and protects the electronic circuitry contained therein from body fluids. Housing 202 may be hermetically sealed and configured for subcutaneous implantation. Electrical feedthroughs provide electrical connection of electrodes 206A and 206B.

[0047] The electronic circuitry may contain components defining an optical sensor 224 of IMD 104A. Optical sensor 224 may include one or more light emitters 226 and oneor more light detectors 228. Optical sensor 224 may be entirely disposed within housing 202 and light emitter(s) 226 may transmit light signals out of housing 202 and light detector(s) 228 may detect light signals external to housing 202 via one or more transparent windows disposed within housing 202. The one or more transparent windows may hermetically seal housing 202 and may define at least a portion of first major surface 204 or second major surface 208.

[0048] In the example shown in FIG. 2 A, IMD 104 A is defined by a length L, a width W, and a thickness or depth D and is in the form of an elongated rectangular prism wherein the length L is much larger than the width W, which in turn is larger than the depth D. In one example, the geometry of IMD 104 A, in particular a width W greater than the depth D, is selected to allow IMD 104A to be inserted under the skin of the patient using a minimally invasive procedure and to remain in the desired orientation during insertion. For example, IMD 104A as shown in FIG. 2A includes radial asymmetries (notably, the rectangular shape) along the longitudinal axis that maintains the device in the proper orientation following insertion. For example, the spacing between proximal electrode 206A and distal electrode 206B may range from 5 millimeters (mm) to 55 mm, 30 mm to 55 mm, 35 mm to 55 mm, and from 40 mm to 55 mm and may be any range or individual spacing from 5 mm to 60 mm. In addition, IMD 104A may have a length L that ranges from 30 mm to about 70 mm. In other examples, the length L may range from 5 mm to 60 mm, 40 mm to 60 mm, 45 mm to 60 mm and may be any length or range of lengths between about 30 mm and about 70 mm. In addition, the width W of major surface 204 may range from 3 mm to 15, mm, from 3 mm to 10 mm, or from 5 mm to 15 mm, and may be any single or range of widths between 3 mm and 15 mm. The thickness of depth D of IMD 104 A may range from 2 mm to 15 mm, from 2 mm to 9 mm, from 2 mm to 5 mm, from 5 mm to 15 mm, and may be any single or range of depths between 2 mm and 15 mm. In addition, IMD 104 A according to an example of the present disclosure is has a geometry and size designed for ease of implant and patient comfort. Examples of IMD 104A described in this disclosure may have a volume of three cubic centimeters (cm) or less, 1.5 cubic cm or less or any volume between three and 1.5 cubic centimeters.

[0049] In the example shown in FIG. 2 A, once IMD 104 A is inserted within patient 102, first major surface 204 faces outwards and towards the skin of patient 102 while second major surface 208 is located opposite first major surface 204. In addition, in theexample shown in FIG. 2A, proximal end 210 and distal end 212 are rounded to reduce discomfort and irritation to surround tissue once IMD 104 A is inserted under the skin of patient 102. IMD 104A and instruments and methods for inserting IMD 104A are described, for example, in U.S. Patent No. 11,311,312 filed on March 11, 2014, issued on April 26, 2022, and entitled “Subcutaneous Delivery Tool,” the entirety of which is herein incorporated by reference in its entirety.

[0050] Proximal electrode 206 A is at or proximate to proximal end 210, and distal electrode 206B is at or proximate to distal end 212. Proximal electrode 206A and distal electrode 206B are used to sense cardiac signals, e.g., ECG signals, and measure interstitial impedance thoracically outside the ribcage, which may be sub-muscularly or subcutaneously. ECG signals and impedance measurements may be stored in a memory of IMD 104 A, and data may be transmitted via integrated antenna 216A to another device, which may be another implantable device or an external device, such as one or more of patient computing devices 106. In some examples, electrodes 206A, 206B are additionally or alternatively used for sensing any bio-potential or physiological signals of interest, which may be, for example, an electrogram (EGM), EEG, electromyogram (EMG), a nerve signal, or any other physiological signal, from any implanted location.

[0051] In the example shown in FIG. 2A, proximal electrode 206A is at or in close proximity to the proximal end 210 and distal electrode 206B is at or in close proximity to distal end 212. In this example, distal electrode 206B is not limited to a flattened, outward facing surface, but may extend from first major surface 204 around rounded edges 222 and / or end surface 214 and onto second major surface 208 so that distal electrode 206B has a three-dimensional curved configuration. In some examples, distal electrode 206B is an uninsulated portion of a metallic, e.g., titanium, part of housing 202.

[0052] In the example shown in FIG. 2A, proximal electrode 206A is located on first major surface 204 and is substantially flat and outward facing. In some examples, proximal electrode 206A utilizes the three-dimensional curved configuration of distal electrode 206B and provide a three-dimensional proximal electrode (not shown in FIG. 2A). Similarly, in other examples distal electrode 206B may utilize a substantially flat, outward facing electrode located on first major surface 204 similar to that shown with respect to proximal electrode 206A.

[0053] The various electrode configurations allow for configurations in which proximal electrode 206A and distal electrode 206B are located on both first major surface 204 and second major surface 208. In other configurations, such as than shown in FIG. 2A, only one of proximal electrode 206A, distal electrode 206B, and optical sensor 224 is located on both major surfaces 204 and 208, and in still other configurations two or more of proximal electrode 206A, distal electrode 206B, and optical sensor 224 are located on one of first major surface 204 or second major surface 208. In some examples, IMD 104A may include electrodes and optical sensors 224 on both major surfaces 204 and 208, such that a total of four electrodes and two optical sensors 224 are included on IMD 104A. Electrodes 206A and 206B may be formed of a plurality of different types of biocompatible conductive material, e.g., stainless steel, titanium, platinum, iridium, or alloys thereof, and may utilize one or more coatings such as titanium nitride or fractal titanium nitride.

[0054] In the example shown in FIG. 2 A, proximal end 210 includes a header assembly 218 that includes one or more of proximal electrode 206A, integrated antenna 216A, anti-migration projections 221, and / or suture hole 220. Integrated antenna 216A allows IMD 104A to transmit and / or receive data. In some examples, integrated antenna 216A may be formed on the opposite major surface as proximal electrode 206A or may be incorporated within housing 202 of IMD 104A. In the example shown in FIG. 2A, antimigration projections 221 are located adjacent to integrated antenna 216A and protrude away from first major surface 204 to inhibit longitudinal movement of IMD 104A. In the example shown in FIG. 2A, anti-migration projections 221 include a plurality (e.g., nine) small bumps or protrusions extending away from first major surface 204. As discussed above, in other examples anti-migration projections 221 may be located on the opposite major surface as proximal electrode 206A and / or integrated antenna 216A. In addition, in the example shown in FIG. 2A, header assembly 218 includes suture hole 220, which provides another means of securing IMD 104 A to patient 102 to inhibit movement of IMD 104 A following insertion. In the example shown in FIG. 2 A, suture hole 220 is located adjacent to proximal electrode 206A. In one example, header assembly 218 is a molded header assembly made from a polymeric or plastic material, which may be integrated or separable from the main portion of IMD 104 A.

[0055] Optical sensor 224 includes one or more light emitters 226 and one or more light detectors 228. In some examples, optical sensor 224 includes a proximal light detector 228 disposed at or around proximal end 210 and a distal light detector 228 disposed at or around distal end 212 (not shown in FIG. 2A). In some examples, the proximal light detector 228 is disposed at a first longitudinal location along housing 202 between light emitter(s) 226 and proximal end 210 and distal light detector 228 is disposed at a second longitudinal location between light emitter(s) 226 and distal end 212. In some examples, light emitter(s) 226 and light detector(s) 228 may be disposed on one of major surfaces 204, 208. In some examples, at least one light emitter 226 and one light detector 228 is disposed on each of major surfaces 204, 208. Each of light detectors 228 may be positioned at least a minimum longitudinal distance away from one or more light emitters 226 disposed on a same surface of major surfaces 204, 208. In some examples, optical sensor 224 is a photoplethysmography (PPG) sensor.

[0056] Each of light emitter(s) 226 or light detector(s) 228 may include a transparent window defining at least a portion of an outer surface of IMD 104 (e.g., at least a portion of one or more of major surfaces 204, 208). The transparent windows may isolate the circuitry and other components of light emitter(s) 226 and light detector(s) 228 from body fluid of patient 102 and facilitate the maintenance of the hermetic seal by housing 202. Each transparent window may be formed from a glass or sapphire. In some examples, each of light emitter(s) 226 or light detector(s) 228 may be positioned beneath a portion of housing 202 formed from a transparent or translucent material (e.g., glass or sapphire).

[0057] Each light emitter 226 may include a light source, such as a light-emitting diode (LED), which may emit light at one or more wavelengths within the visible and / or near-infrared (NIR) spectra. For example, each light emitter 226 is configured to emit light with wavelengths of about 680 nanometers (nm), 720 nm, 760 nm, 800 nm, or any other suitable wavelengths. IMD 104 may use the one or more wavelengths of light emitted by light emitter 226 to determine values for one or more physiological parameters, including, but are not limited to, tissue oxygen saturation (StOi), blood oxygen saturation (SpOi), tissue hemoglobin index (THI), blood pressure level, or the like.

[0058] Light emitter(s) 226 may emit light into a target site of patient 102. The target site generally includes blood within blood vessels in the interstitial space around IMD 104A when IMD 104A is implanted in patient 102. Light emitter(s) 206 may emit lightdirectionally (e.g., to a side of IMD 104A). In some examples, the light is a cloud of light directly generally inwards (e.g., towards the musculature of patient 102 and away from the skin of patient 102). In some examples, the light is non-directional once emitted from light emitter(s) 226).

[0059] In some examples, light emitter(s) 226 emit visible (VIS) and / or NIR light at multiple wavelengths, either simultaneously or sequentially. Light emitter(s) 226 may emit light at one or more wavelengths capable of shallow penetration into tissue (e.g., tissue relatively close to IMD 104A as well as at one or more wavelengths capable of deeper penetration into tissue (e.g., tissue relatively further away from IMD 104A). In such examples, using wavelengths capable of penetrating the tissue to different depths may enable the elimination of measurement errors, which may be caused by factors such as fibrous tissue encapsulation that may form around IMD 104A post implant. In some examples, using wavelengths capable of penetrating the tissue to different depths may allow IMD 104A to identify and reduce the effects of common errors associated with the different light signals, such as, but are not limited to, tissue formation, adhesion, changes in tissue content.

[0060] Light emitter(s) 226 may include a single photodiode that is capable of emitting light at a range of wavelengths. In some examples, light emitter(s) 226 include multiple photodiodes, each photodiode being configured to emit light at one or more different wavelengths. Light detector(s) 228 may receive light from light emitter(s) 226 that is reflected by the tissue and generate electrical signals indicating intensities of the light detected by light detector(s) 228. IMD 104A may evaluate the electrical signals to determine values for one or more physiological parameters (e.g., oxygen saturation level, blood pressure level).

[0061] The physiological parameters of patient 102 may affect an amount of light absorbed by blood within tissue adjacent to IMD 104A and / or an amount of light reflected by the tissue. IMD 104A may receive the reflected light via light detector(s) 228 and determine physiological parameter values based on the received light signals. For example, IMD 104A is configured to determine a blood pressure level of patient 102 based on the light signals received via light detector(s) 228. In some examples, IMD 104A is configured to determine the blood pressure level of patient 102 based on the received light signals via a PPG technique.

[0062] FIG. 2B is a perspective drawing illustrating another IMD 104B, which may be another example configuration of IMD 104 from FIG. 1. IMD 104B of FIG. 2B may be configured substantially similarly to IMD 104 A of FIG. 2 A, with differences between them discussed herein.

[0063] IMD 104B may include a leadless, subcutaneously implantable monitoring device, e.g., an ICM. IMD 104B includes housing having a base 223 and an insulative cover 222. Proximal electrode 206C and distal electrode 206D may be formed or placed on an outer surface of cover 222. Various circuitries and components of IMD 104B may be formed or placed on an inner surface of cover 222, or within base 223. In some examples, a battery or other power source of IMD 104B may be included within base 223. In the illustrated example, antenna 216B is formed or placed on the outer surface of cover222 but may be formed or placed on the inner surface in some examples. In some examples, insulative cover 222 may be positioned over an open base 223 such that base223 and cover 222 enclose the circuitries and other components and protect them from fluids such as body fluids. The housing including base 223 and insulative cover 222 may be hermetically sealed and configured for subcutaneous implantation. At least a portion of base 223 and / or cover 222 may be transparent or translucent, e.g., to facilitate the transmission of light out of IMD 104B by light emitter(s) 226 and the detection of lights signals by light detector(s) 228.

[0064] Circuitries and components may be formed on the inner side of insulative cover222, such as by using flip-chip technology. Insulative cover 222 may be flipped onto base223. When flipped and placed onto base 223, the components of IMD 104B formed on the inner side of insulative cover 222 may be positioned in a gap 225 defined by base 223. Electrodes 206C and 206D and antenna 216B may be electrically connected to circuitry formed on the inner side of insulative cover 222 through one or more paths (not shown) formed through insulative cover 222. Insulative cover 222 may be formed of sapphire (i.e., corundum), glass, perylene, and / or any other suitable insulating material. Insulative cover 222 may be at least partially or entirely transparent or translucent. Base 223 may be formed from titanium or any other suitable material (e.g., a biocompatible material). Electrodes 206C and 206D may be formed from any of stainless steel, titanium, platinum, iridium, or alloys thereof. In addition, electrodes 206C and 206D may be coated with amaterial such as titanium nitride or fractal titanium nitride, although other suitable materials and coatings for such electrodes may be used.

[0065] In the example shown in FIG. 2B, the housing of IMD 104B defines a length L, a width W, and thickness or depth D, and is in the form of an elongated rectangular prism wherein the length L is much larger than the width W, which in turn is larger than the depth D, similar to IMD 104 A of FIG. 2 A. For example, the spacing between proximal electrode 206C and distal electrode 206D may range from 5 mm to 50 mm, from 30 mm to 50 mm, from 35 mm to 45 mm, and may be any single spacing or range of spacings from 5 mm to 50 mm, such as approximately 40 mm. In addition, IMD 104B may have a length L that ranges from 5 mm to about 70 mm. In other examples, the length L may range from 30 mm to 70 mm, 40 mm to 60 mm, 45 mm to 55 mm, and maybe any single length of range of lengths from 5 mm to 50 mm, such as approximately 45 mm. In addition, the width W may range from 3 mm to 15 mm, 5 mm to 15 mm, 5 mm to 10 mm, and may be any single width or range of widths from 3 mm to 15 mm, such as approximately 8 mm. The thickness or depth D of IMD 104B may range from 2 mm to 15 mm, from 5 mm to 15 mm, or from 3 mm to 5 mm, and may be any single depth or range of depths between 2 mm and 15 mm, such as approximately 4 mm. IMD 104B may have a volume of three cubic centimeters (cm3) or less, or 1.5 cm3or less, such as approximately 1.4 cm3.

[0066] In the example shown in FIG. 2B, once IMD 104B is inserted subcutaneously within patient 102, the outer surface of cover 222 faces outwards and towards the skin of patient 102. In addition, as shown in FIG. 2B, proximal end 226 and distal end 228 are rounded to reduce discomfort and irritation to surround tissue once inserted under the skin of patient 102. In addition, edges of IMD 104B may be rounded.

[0067] FIG. 3 is a block diagram illustrating an example configuration of IMD 104 of FIG. 1. As shown in FIG. 3, IMD 104 may include processing circuitry 302, memory 304, sensing circuitry 306 coupled to electrodes 206A and 206B (collectively referred to herein as “electrodes 206”), to optical sensor 224, and to one or more sensor(s) 308, and communications circuitry 310.

[0068] Processing circuitry 302 may include fixed function circuitry and / or programmable processing circuitry. Processing circuitry 302 may include any one or more of a microprocessor, a controller, a GPU, a TPU, a DSP, an ASIC, a FPGA, or equivalent discrete or analog logic circuitry. The functions attributed to processing circuitry 302herein may be embodied as software, firmware, hardware, or any combination thereof. In some examples, memory 304 includes computer-readable instructions that, when executed by processing circuitry 302, cause IMD 104 and processing circuitry 302 to perform various functions attributed herein to IMD 104 and processing circuitry 302. Memory 304 may include any volatile, non-volatile, magnetic, optical, or electrical media, such as RAM, ROM, NVRAM, EEPROM, flash memory, or any other digital media.

[0069] Sensing circuitry 306 may sense an electrocardiogram (ECG) signal and measure impedance, e.g., of tissue proximate to IMD 104, via electrodes 206. The measured impedance may vary based on respiration, cardiac pulse, or flow, and a degree of perfusion or edema. Processing circuitry 302 may determine physiological parameter values relating to respiration, fluid retention, cardiac pulse or flow, perfusion, and / or edema based on the measured impedance. In some examples, processing circuitry 302 may identify features of the sensed ECG, such as heart rate, heart rate variability, T-wave altemans, intra-beat intervals (e.g., QT intervals), and / or ECG morphologic features. Processing circuitry 302 may determine that patient 102 has experienced an external impact based on changes in identified features of the sensed ECG (e.g., changes in the heart rate) in addition to changes in other physiological parameters (e.g., changes in acceleration experienced by patient 102, changes in posture of patient 102, changes in g- force on patient 102). The techniques described in this disclosure may be implemented, at least in part, in hardware, software, firmware, or any combination thereof. For example, various aspects of the techniques may be implemented within one or more microprocessors, DSPs, ASICs, FPGAs, or any other equivalent integrated or discrete logic QRS circuitry, as well as any combinations of such components, embodied in external devices, such as physician or patient programmers, stimulators, or other devices. The terms “processor” and “processing circuitry” may generally refer to any of the foregoing logic circuitry, alone or in combination with other logic circuitry, or any other equivalent circuitry, and alone or in combination with other digital or analog circuitry.

[0070] IMD 104 may include one or more sensors 308, such as one or more accelerometers, gyroscopes inertial measurement units (IMUs), microphones, oximeters, optical sensors 224 (e.g., including one or more light emitters 226 and one or more light detectors 228), temperature sensors, pressure sensors, and / or chemical sensors. Sensing circuitry 306 may include one or more filters and amplifiers for filtering and amplifyingsignals from one or more of electrodes 206 and / or sensor(s) 308. Sensing circuitry 306 and / or processing circuitry 302 may include a rectifier, filter and / or amplifier, a sense amplifier, comparator, and / or analog-to-digital converter. Processing circuitry 302 may determine physiological parameter data 320, e.g., values of physiological parameters of patient 102, based on signals from sensor(s) 308, which may be stored as data 316 in memory 304. Physiological parameter may include a posture of patient 102, acceleration of the body (e.g., of the torso) of patient 102, a g-force on patient 102, a heart rate of patient 102, a respiration rate of patient 102, a stress hormone level of patient 102, a body temperature of patient 102, glucose level of patient 102, blood pressure of patient 102, EEG signals of patient 102, change in electrocardiogram (ECG) morphology of patient 102, change in EGM morphology of patient 102, impedance between two or more locations on patient 102, an oxygen saturation of patient 102 or a rate of change of a physiological parameter.

[0071] Sensing circuitry 306 may continuously or periodically sensed physiological signals via electrodes 206 and / or sensor(s) 308. Processing circuitry 302 may receive an instruction to sense physiological signals (e.g., from computing system 110, patient computing devices 106) and cause sensing circuitry 306 to sense physiological signals from patient 102 in response to the instruction.

[0072] In addition to data 316, memory 304 may store application(s) 312 executable by processing circuitry 302. Application(s) 312 may include physiological parameter monitoring application 314 executable by processing circuitry 302 to determine physiological parameter values based on physiological signals sensed via sensing circuitry 306, electrodes 206, and / or sensor(s) 308. Processing circuitry 302 may execute physiological parameter monitoring application 314 to compare physiological parameter values (e.g., physiological parameter data 320) against threshold conditions 318 stored in data 316 and select a sensing mode of a plurality of sensing modes based on the comparison.

[0073] Processing circuitry 302 may execute physiological parameter monitoring application 314 to compare physiological parameter values of a single type (e.g., blood pressure levels only) or of two or more types (e.g., blood pressure level and heart rate) against corresponding threshold conditions 318 stored in data 316. In some examples, when processing circuitry 302 executes physiological parameter monitoring application314, processing circuitry 302 selects a same sensing mode (e.g., a current sensing mode) based on satisfaction of threshold conditions 318 and selects a sensing mode different from a current sensing mode based on a failure to satisfy threshold conditions 318. In such examples, satisfaction of threshold conditions 318 may correspond to onset of a medical condition, changes in an existing medical condition, onset of the effects of a medical therapy, and / or changes in medical therapies. In some examples, when processing circuitry 302 executes physiological parameter monitoring application 314, processing circuitry 302 selects a different sensing mode (e.g., from a current sensing mode) based on a failure to satisfy threshold conditions 318 and selects the same sensing mode based on satisfaction of threshold conditions 318. In such examples, a failure to satisfy threshold conditions 318 may correspond to onset of a medical condition, changes in an existing medical condition, onset of the effects of a medical therapy, and / or changes in medical therapies. Processing circuitry 302 may receive an indication that patient 102 is receiving a new medical therapy and / or that there are changes to applied medical therapies from one or more other computing devices (e.g., from computing system 110 and / or clinician computing devices 128).

[0074] Threshold conditions 318 may include, but are not limited to, threshold physiological parameter values, threshold amounts, or threshold percentages. Threshold physiological parameter values may include, but are not limited to, a threshold baseline parameter value for a physiological parameter, a threshold maximum parameter value, or a threshold minimum parameter value. Processing circuitry 302 may determine that a physiological parameter value satisfies a threshold maximum parameter value based on a determination that the physiological parameter value is greater than or equal to or is less than or equal to the threshold maximum parameter value. Processing circuitry 302 may determine that a physiological parameter value satisfies a threshold minimum parameter value based on a determination that the physiological parameter value is greater than or equal to or is less than or equal to the threshold minimum parameter value. Threshold amounts may include a threshold quantity of physiological parameter values from a prior time period that satisfy another threshold condition (e.g., a threshold physiological parameter values). Threshold percentages may include a threshold percentage of physiological parameters from a prior time period that satisfy another threshold condition.

[0075] In some examples, processing circuitry 302 determines that threshold conditions 318 are satisfied based on a determination that less than a threshold amount or threshold percentage of physiological parameter values from a prior time period are less than or equal to a threshold maximum parameter value. In some examples, processing circuitry 302 determines that threshold conditions 318 are satisfied based on a determination that more than a threshold amount or threshold percentage of physiological parameter values from a prior time period are less than or equal to a threshold maximum parameter value. In some examples, processing circuitry 302 determines that threshold conditions 318 are satisfied based on a determination that less than a threshold amount or threshold percentage of physiological parameter values from a prior time period are less than or equal to a threshold minimum parameter value. In some examples, processing circuitry 302 determines that threshold conditions 318 are satisfied based on a determination that more than a threshold amount or threshold percentage of physiological parameter values from a prior time period are less than or equal to a threshold minimum parameter value.

[0076] The plurality of sensing modes may be stored in memory 304. Stored instructions for each sensing mode may include sensing parameter values including, but is not limited to, sensing frequency. Sensing parameter values of different sensing modes may be different. Processing circuitry 302 may retrieve and execute instructions for a selected sensing mode (e.g., selected via execution of physiological parameter monitoring application 314) to cause processing circuitry 302 and sensing circuitry 306 to sense physiological signals from patient 102 in accordance with the selected sensing mode.

[0077] By causing processing circuitry 302 to select different modes based on satisfaction, or lack thereof, of threshold conditions 318, IMD 104 may increase the sensing of physiological signals (e.g., via increasing sensing frequency) during time periods when additional monitoring is required (e.g., in response to onset of a medical condition, changes in an existing medical condition, onset of the effects of a medical therapy, and / or changes in medical therapies), and decrease the sensing of physiological signals (e.g., back to a baseline sensing frequency) during periods when additional monitoring is not required (e.g., when patient 102 is not experiencing the medical condition, when patient 102 is experiencing an improvement in a status of the medical condition). Switching between increased sensing and decreased sensing modes may causeIMD 104 to reduce overall power consumption when monitoring physiological signals, which may increase a lifespan of a power source of IMD 104 and, by extension, of IMD 104.

[0078] Communications circuitry 310 may include any suitable hardware, firmware, software, or any combination thereof for wireless communication with another device. Communications circuitry 310 may be configured to transmit and / or receive signals via inductive coupling, electromagnetic couple, Near Field Communication (NFC), Radio Frequency (RF) communication, Bluetooth®, WiFi, or other proprietary or nonproprietary wireless communications schemes.

[0079] FIG. 4 is a block diagram illustrating an example configuration of a patient computing device 106, which may correspond to either (or both operating in coordination) of patient computing devices 106 A and 106B. In some examples, patient computing device 106 includes a smartphone, a laptop, a table computer, a personal digital assistant (PDA), a smartwatch, or other wearable computing devices.

[0080] As shown in the example illustrated in FIG. 4, computing device 106 may be logically divided into user space 402, kernel space 404, and hardware 406. Hardware 406 may include one or more hardware components that provide an operating environment for components executed in user space 402 and kernel space 404. User space 402 and kernel space 404 may represent different sections or segmentations of memory, where kernel space 404 provides higher privileges to processes and threshold than user space 402. For instance, kernel space 404 may include operating system 432, which operates with higher privileges than components executing in user space 402.

[0081] As shown in FIG. 4, hardware 406 includes process circuitry 420, memory 422, one or more input devices 424, one or more output devices 426, one or more sensors 428, and communications circuitry 429. Although shown in FIG. 4 as a stand-alone device for purposes of examples, computing device 106 may be any component or system that includes processing circuitry or other suitable computing environment for executing software instructions and, for example, need not necessarily include one or more elements shown in FIG. 4.

[0082] Processing circuitry 420 is configured to implement functionality and / or process instructions for execution within computing device 106. For example, processing circuitry 420 may be configured to receive and process instructions stored in memory 420that provide functionality of components included in kernel space 404 and user space 402 to perform one or more operations in accordance with techniques of this disclosure.Examples of processing circuitry 420 may include, any one or more microprocessors, controllers, GPUs, TPUs, DSPs, ASICs, FPGAs, or equivalent discrete or integrated logic circuitry.

[0083] Memory 422 may be configured to store information within computing device 106, for processing during operation of computing device 106. Memory 422, in some examples, is described as a computer-readable storage medium. In some examples, memory 422 includes a temporary memory or a volatile memory. Examples of volatile memories include RAM, DRAM, SRAM, and other forms of volatile memories known in the art. Memory 422, in some examples, also includes one or more memories configured for long-term storage of information, e.g., including non-volatile storage elements.Examples of such non-volatile storage elements include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories. In some examples, memory 422 includes cloud-associated storage.

[0084] One or more input devices 424 of computing device 106 may receive input, e.g., from patient 102, clinician 130, or another user. Examples of input are tactile, audio, kinetic, and optical input. Input devices 424 may include, as examples, a mouse, keyboard, voice responsive system, camera, buttons, control pad, microphone, presence-sensitive or touch-sensitive component (e.g., screen), or any other device for detecting input from a user or a machine.

[0085] One or more output devices 426 of computing device 106 may generate output, e.g., to patient 102 or another user. Examples of output are tactile, haptic, audio, and visual output. Output devices 426 of computing device 106 may include a presencesensitive screen, sound card, video graphics adapter card, speaker, cathode ray tube (CRT) monitor, liquid crystal display (LCD), light emitting diodes (LEDs), or any type of device for generating tactile, audio, and / or visual output.

[0086] One or more sensors 428 of computing devices 106 may sense physiological parameters or physiological signals of patient 102. Sensor(s) 428 may include electrodes, accelerometers (e.g., 3-axis accelerometers), IMUs, gyroscopes, optical sensors,impedance sensors, temperature sensors, pressure sensors, heart sound sensors (e.g., microphones or accelerometers), and other sensors.

[0087] Communication circuitry 429 of computing device 106 may communicate with other devices by transmitting and receiving data. Communication circuitry 429 may receive data from IMD 104, such as physiological signals and / or physiological parameter values, from communication circuitry 310 in IMD 104. Communication circuitry 429 may include a network interface card, such as an Ethernet card, an optical transceiver, a radio frequency transceiver, or any other type of device that can send and receive information. For example, communication circuitry 429 may include a radio transceiver configured for communication according to standards or protocols, such as 3G, 4G, 5G, WiFi (e.g., 802.11 or 802.15 ZigBee), Bluetooth®, or Bluetooth® Eow Energy (BEE).

[0088] As shown in FIG. 4, health monitoring application 410 executes in user space 402 of computing device 106, health monitoring application 410 may be logically divided into presentation layer 412, application layer 414, and data layer 416. Presentation layer 412 may include a user interface (UI) component 430, which generates and renders user interfaces of health monitoring application 410.

[0089] Data layer 416 may include threshold condition data 450 and physiological parameter data 452, which may be received from IMD 104 via communications circuitry 429 and stored in memory 422 by processing circuitry 420. Threshold condition data 450 may contain threshold conditions (e.g., threshold conditions 418) corresponding to different physiological parameters. IMD 104 may receive threshold conditions from clinician 130, clinician computing device 128, computing system 110, or other computing devices or systems connected to network 108 (e.g., via input device(s) 424 and / or communications circuitry 429). Computing device 106 may determine or receive changes in physiological parameter values and store the changes in physiological parameter values in physiological parameter data 452. In some examples, computing device 106 may receive physiological parameter values from IMD 104.

[0090] Application layer 414 may include, but is not limited to, physiological parameter analyzer 440. Physiological parameter analyzer 440 may monitor sensed physiological parameter values (e.g., from IMD 104) and select sensing modes based on the sensed values (e.g., in a similar manner as the execution of physiological parameter monitoring application 314). Physiological parameter analyzer 440 may output (e.g., viaoutput device(s) 426) notifications to patient 102 and / or clinician 130 in response to satisfaction of one or more threshold conditions within threshold condition data 450 and / or selection of a sensing mode. Processing circuitry 302 may receive an indication that patient 102 is receiving a new medical therapy and / or that there are changes to applied medical therapies via input device(s) 424 and / or from one or more other computing devices (e.g., from patient computing devices 106 and / or clinician computing devices 128). System 100 may track changes in medical therapies received by patient 102 (e.g., changes in medications taken by patient 102 and / or changes in medication history of patient 102) via patient computing devices 106. In other examples, system 100 may track the changes via clinician computing devices 128 and / or computing system 100 (e.g., via HMS 116).

[0091] FIG. 5 is a block diagram illustrating an operating perspective of HMS 116. HMS 116 may be implemented in a computing system 110, which may include hardware components such as processing circuitry 112, memory 114, and communications circuitry, embodies in one or more physical devices. FIG. 5 provides an operating perspective of HMS 116 when hosted as a cloud-based platform. In the example of FIG. 5, components of HMS 116 are arranged according to multiple logical layers that implement the techniques of this disclosure. Each layer may be implemented by one or more modules comprised of hardware, software, or a combination of hardware and software.

[0092] Computing devices, such as patient computing devices 106 and / or client computing devices 128, operate as clients that communicate with HMS 116 via interface layer 500. The computing devices typically execute client software applications, such as desktop application(s), mobile application(s), and web application(s). Interface layer 500 represents a set of application programming interfaces (API) or protocol interfaces presented in and supported by HMS 116 for the client software applications. Interface layer 500 may be implemented with one or more web servers.

[0093] As shown in FIG. 5, HMS 116 also includes an application layer 502 that represents a collection of services 506 for implementing the functionality ascribed to HMS 116 herein. Application layer 502 receives information from client applications, e.g., data from patient computing devices 106, some or all of which may have been received from IMD 104, and further processes the information according to one or more of services 506 to respond to the information. Application layer 502 may be implemented as one or morediscrete software services 506 executed on one or more application servers, e.g., physical or virtual machines. That is, the application servers provide runtime environments for execution of services 506. In some examples, the functionality interface layer 500 as described above and the functionality of application layer 502 may be implemented at the same server. Services 506 may communicate via a logical service bus 511. Service bus 511 generally represents a logical interconnection or set of interfaces that allows different services 506 to send messages to other services, such as by a publish / subscription communication model.

[0094] Data layer 504 of HMS 116 provides persistence for information in HMS 116 using one or more data repositories 508. A data repository 508, generally, may be any data structure or software that stores and / or manages data. Examples of data repositories 508 include, but are not limited to, relational databases, multi-dimensional databases, maps, and / or hash tables.

[0095] As shown in FIG. 5, each of services 510-514 is implemented in modular form within HMS 116. Although shown as separate modules for each service, in some examples the functionality of two or more services may be combined into a single module or component. Each of services 510-514 may be implemented in software, hardware, or a combination of hardware and software. Moreover, services 510-514 may be implemented as standalone devices, separate virtual machines or containers, processes, threads or software instructions generally for execution on one or more physical processors. Record management service 514 may store received data such as threshold condition data 520 and physiological parameter date 522 from client computing devices (e.g., from patient computing devices 106, IMD 104).

[0096] Threshold condition detection service 510 may compare threshold conditions (e.g., stored in threshold condition data 520) against physiological parameters (e.g., stored in physiological parameter data 522) and determine whether the threshold conditions are satisfied. In some examples, threshold condition detection service 510 is configured to compare physiological parameter values from a prior time period against one or more threshold conditions to determine whether the one or more threshold conditions are satisfied. The one or more threshold conditions may correspond to a single type of physiological parameter or to two or more different types of physiological parameters.

[0097] Physiological parameter monitoring service 512 may monitor physiological parameters of patient 102 and control sensing parameters applied by IMD 104 to sense physiological signals corresponding to physiological parameters. In some examples, physiological parameter monitoring service 512 is configured to adjust a sensing mode of IMD 104 to adjust sensing parameters (e.g., sensing frequency). Physiological parameter monitoring service 512 is configured to adjust the sensing mode and / or sensing parameters of IMD 104 in response to a determination by threshold condition detection service 510 (e.g., based on satisfaction, or lack thereof, of one or more threshold conditions) that a condition of patient 102 requires increased or decreased monitoring of physiological parameters. In some examples, physiological parameter monitoring service 512 is configured to adjust the sensing mode and / or sensing parameters of IMD 104 in response to a determination by threshold condition detection service 510 that one or more threshold conditions are satisfied. In some examples, physiological parameter monitoring service 512 is configured to adjust the sensing mode and / or sensing parameters of IMD 104 in response to a determination by threshold condition detection service 510 that one or more threshold conditions are not satisfied.

[0098] In some examples physiological parameter monitoring service 512 is configured to temporarily adjust sensing modes and / or sensing parameters of IMD 104 to temporarily increase sensing frequency, e.g., to validate the selection of current sensing modes and / or sensing parameters. Physiological parameter monitoring service 512 may perform the temporary adjustments based on one or more of, but is not limited to, a determination that at least a threshold period of time has elapsed since a prior adjustment of sensing modes and / or sensing parameters or a random selection of a starting time and ending time for the temporary adjustments.

[0099] FIG. 6 is a graph 602 illustrating example sensed physiological parameter values 610 over time. Graph 602 illustrates changes in physiological parameter values 610 (e.g., changes in blood pressure 604) over time 606 and across a plurality of time periods 608A - N (collectively referred to herein as “time periods 608”). Graph 602 illustrates monitoring of physiological parameter values 610 under different sensing modes 614A, 614B (collectively referred to herein as “sensing modes 614”) in response to whether prior physiological parameter values satisfy threshold condition 612. While FIG. 6 is primarily described with reference to two sensing modes 614, system 100 as described herein mayswitch between three or more different sensing modes 614 in accordance with the example techniques described herein.

[0100] While FIG. 6 is illustrated and described primarily with reference to blood pressure 604, the example changes in sensing parameters and / or sensing modes described herein may be applied to any other example physiological parameters described herein. Additionally, while FIG. 6 is primarily illustrated and described below with reference to satisfaction of threshold condition 612 being at least a threshold amount or percentage of physiological parameter values being greater than or equal to threshold condition 612, in other examples threshold condition 612 may include any other example threshold conditions described herein and may be satisfied in any other manner described herein, e.g., as described in greater detail in FIGS. 3-5.

[0101] In the example illustrated in graph 602, physiological parameter values 610 (also referred to herein as “values 610”) may represent a blood pressure 604 of patient 102. Blood pressure 604 of patient 102 may be represented in millimeters of mercury (mmHg). Graph 602 illustrates changes in values 610 of blood pressure 610 over time 606. Time 606 may be represented in terms of time windows of identical length (e.g., in terms of 24-hour days). A plurality of consecutive time windows may define one of time periods 608. In some examples, as illustrated in graph 602, each of time periods 608 may have a duration of up to one month or thirty days.

[0102] During time period 608A, system 100 may monitor and sense values 610 under a first sensing mode 614A. Under first sensing mode 614A, system 100 may monitor and sense values 610 at an increased frequency, e.g., compared to second sensing mode 614B. In some examples, system 100 is configured to sense up to four or four or more values 610 (e.g., at a respective number of occurrences, during a respective number of detection windows) within each time window. Under first sensing mode 614A, system 100 may obtain a more continuous and / or representative reading of changes in values 610 throughout the duration of each time window, obtain a more accurate average of values 610 within each time window, and / or obtain a more granular reading of values 610 within each time period 608 compared to second sensing mode 614B.

[0103] In some examples, when system 100 is sensing values 610 under first sensing mode 614A, the sensing occurrences and / or detection windows may be evenly distributed through the duration of the time window. For example, system 100 may sense four values610 within a 24-hour time window by sensing values 610 at 6-hour intervals. In some examples, system 100 may randomly distribute the occurrences and / or detection windows across the duration of the time window. In some examples, system 100 distributes the occurrences and / or detection windows to avoid certain portions of the time window and / or to concentrate sensing during other portions of the time window. For example, system 100 may distribute the occurrences and / or detection windows to increase the sensing frequency of values 610 during nighttime hours and to reduce the sensing frequency of values 610 during daytime hours, or vice versa.

[0104] In some examples, as illustrated in graph 602, system 100 is configured to sense values 610 under a higher sensing frequency setting and / or higher-sensing- frequency sensing mode when system 100 initially begins to sense values 610. System 100 may sense values 610 under a higher sensing frequency setting and / or higher-sensing- frequency sensing mode for at least a threshold number of time periods 608 (e.g., at least one time period 608) after beginning to sense values 610.

[0105] System 100 may determine, based on sensed values 610 from time period 608A, whether threshold condition 612 is satisfied. Threshold condition 612 may correspond to occurrence of a medical condition (e.g., hypertension), a change in a status of a medical condition, effects of a medical therapy, and / or effects corresponding to changes in medical therapy. In some examples, as illustrated in graph 602, threshold condition 612 may correspond to hypertension and may include a threshold parameter value (e.g., threshold blood pressure value). In such example, the threshold blood pressure value may be at least 130 mm Hg. In some examples, as illustrated in graph 602, system 100 determines that threshold condition 612 is satisfied based on a determination that at least a threshold amount or percentage (e.g., up to 80%) of values 610 within time period 608A is greater than or equal to threshold condition 612. Based on a determination that values 610 from time period 608A satisfy threshold condition 612, system 100 may cause IMD 104 to sense values 610 from patient 102 during time period 608B in first sensing mode 614A. In other examples, in response to a determination that values 610 from time period 608A satisfy threshold condition 612, system 100 causes IMD 104 to sense values 610 from patient 102 during time period 608B in second sensing mode 614B or in another sensing mode (e.g., different from first sensing mode 614A or second sensing mode 614B).

[0106] System 100 may repeat the process described above with respect to time period 608B for each of time periods 608. System 100 may select a sensing mode (e.g., first sensing mode 614A, second sensing mode 614B, another sensing mode) and / or sensing parameter values (e.g., sensing frequency) for each of time periods 608 based on sensed values 610 from a prior time period 608. For example, system 100 is configured to select a sensing mode and / or sensing parameter value(s) for time period 608C based on sensed values 610 from time period 608B, for time period 608D based on sensed values 610 from time period 608C, etc. In the example illustrated in graph 602, system 100 may select first sensing mode 614A and / or sensing parameter value(s) corresponding to an increased sensing frequency in response to satisfaction of threshold condition 612, e.g., as illustrated with respect to time periods 608A, 608B, and 608N. In such examples, system 100 may select second sensing mode 614B and / or sensing parameter value(s) corresponding to a decreased / baseline sensing frequency (e.g., about one detection occurrence / detection window per time window) in response to a failure to satisfy threshold condition 612, e.g., as illustrated with respect to time periods 608C, 608D. In some examples, system 100 selects second sensing mode 614B in response to a failure to satisfy threshold condition 612, and vice versa.

[0107] In some examples, system 100 is configured to receive information (e.g., from clinician 130, patient 102) corresponding to a selected sensing mode and / or sensing parameter values. In such examples, system 100 may cause IMD 104 to sense values 610 in accordance with the selected sensing mode and / or sensing parameter values, e.g., independent from the determinations made by system 100 regarding satisfaction of threshold condition 612 as described above.

[0108] FIG. 7 is a flowchart illustrating an example process of monitoring one or more physiological parameters. While FIG. 7 is primarily described herein with respect to blood pressure 604 of patient 102 and threshold condition 612, the example process illustrated in FIG. 7 may be applied to other physiological parameters and threshold conditions described herein. In addition, while FIG. 7 illustrates a plurality of steps in a first order, the devices, systems, and methods described herein may apply the plurality of steps illustrated in FIG. 7 in any other order.

[0109] System 100 may sense physiological parameter values (e.g., values 610) over a time period (e.g., time period 608) in a first sensing mode (e.g., first sensing mode 614A)(702). IMD 104 of system 100 may sense physiological signals from patient 102 via one or more of electrodes 206 or optical sensors 224. For example, light detector(s) 228 of optical sensor 224 on IMD 104 may detect light emitted from light emitter(s) 226 of optical sensor 224 and reflected by blood of patient 102 and generate an electrical signal in response. IMD 104, patient computing device 106, and / or computing system 110 may determine physiological parameter values based at least in part on the physiological signals. For example, processing circuitry 302, processing circuitry 420, and / or HMS 116 may determine blood pressure 604 of patient 102 based on the electrical signal generated by light detector(s) 228. Each physiological parameter value (e.g., each of values 610) may correspond to a different time 606 and may be associated with a respective time stamp. System 100 may transmit the determined physiological parameter values and corresponding information (e.g., corresponding time stamps) to one or more of patient computing devices 106, computing system 100, clinician computing devices 128, or one or more other computing devices / systems via network 108. System 100 may store the determined physiological parameter values and corresponding information in one or more of memory 304 of IMD 104, data layer 416 of health monitoring application 410 executed by patient computing device 106, or data layer 504 of HMS 116.

[0110] System 100 may determine whether a threshold amount or percentage of the sensed physiological parameter values satisfy a threshold parameter value (e.g., threshold condition 612) (704). System 100 (e.g., one or more of IMD 104, patient computing device 106, or computing system 110 of system 100) may retrieve one or more threshold conditions stored in memory 304, data layer 416, and / or data layer 504. The one or more threshold conditions may include one or more threshold parameter values. Each threshold parameter value may correspond to a specific physiological parameter. For example, threshold condition 612 may represent a threshold blood pressure level and may correspond to a blood pressure 604 of patient 102.

[0111] System 100 may compare sensed physiological parameter values from a prior time period 608 (e.g., from an immediately prior time period 608) against the one or more threshold conditions to determine whether the one or more threshold conditions are satisfied. In some examples, system 100 determines that the one or more threshold conditions are satisfied based on a determination that a threshold amount or percentage of the sensed physiological parameter values satisfy a threshold parameter value. In someexamples, system 100 determines that a physiological parameter value satisfies the threshold parameter value if the physiological parameter value is greater than or equal to the threshold parameter value. In some examples, system 100 determines that a physiological parameter value satisfies the threshold parameter value if the physiological parameter value is less than or equal to the threshold parameter value. The threshold percentage may be at least 80% (e.g., at least 90%, at least 95%). In some examples, system 100 determines that the one or more threshold conditions are satisfied based on a determination that less than the threshold amount or percentage of values satisfy the threshold parameter value. In some examples, system 100 determines whether at least the threshold amount or percentage the sensed physiological parameter values satisfy the threshold parameter value in accordance with any of the example techniques previously described herein.

[0112] In response to a determination that at least the threshold amount or percentage the sensed physiological parameter values satisfy the threshold parameter value (“YES” branch of step 704), system 100 may sense physiological parameter values over a time period (e.g., a following time period) in the first sensing mode (702). In response to a determination that less than the threshold amount or percentage of the sensed physiological parameter values satisfy the threshold parameter value (“NO” branch of step 704), system 100 may sense physiological parameter values over a time period (e.g., a following time period) in a second sensing mode (e.g., second sensing mode 614B) (706).

[0113] One or more sensing parameters of the second sensing mode may be different from one or more sensing parameters of the first sensing mode. For example, a sensing frequency of the second sensing mode may be different from (e.g., greater than, less than) the sensing frequency of the first sensing mode. In some examples, having less than the threshold amount or percentage the sensed physiological parameter values satisfy the threshold parameter value may correspond to an indication of an absence of a medical condition (e.g., hypertension), or an improvement in a medical condition. In such examples, system 100 may sense physiological parameter values in the second sensing mode (e.g., with a reduced sensing frequency) to reduced power consumption by IMD 104. In some examples, having less than the threshold amount or percentage the sensed physiological parameter values satisfy the threshold parameter value may correspond to an indication of an onset of a medical condition (e.g., hypertension), a change in a status of amedical condition (e.g., an increase in severity of the medical condition), onset of the effects of a medical therapy on patient 102, and / or effects of change in one or more medical therapies received by patient 102. In such examples, system 100 may sense physiological parameter values in the second sensing mode with an increased sensing frequency to improve the accuracy and responsiveness of system 100, e.g., in response to variations in physiological parameter values over time.

[0114] In some examples, system 100 may receive, e.g., from clinician 130, patient 102, and / or one or more other individuals, instructions to sense physiological parameter values in a specific sensing mode and / or according to specific sensing parameter values. In such examples, system 100 may cause IMD 104 to sense physiological parameter values in accordance with the specific sensing mode and / or according to specific sensing parameter values, e.g., and independent of determinations made by system 100 at step 706. In such examples, system 100 may continue to cause IMD 104 to sense physiological parameter values in accordance with the specific sensing mode and / or according to specific sensing parameter values until system 100 receives instructions to stop and / or to switch back to the process illustrated in FIG. 7, e.g., from clinician 130, patient 102, and / or one or more other individuals.

[0115] System 100 may determine whether at least a threshold amount or percentage of the sensed physiological parameter values (e.g., sensed under the second sensing mode) satisfies the threshold parameter value (e.g., threshold condition 612) (704). System 100 may make the determination in accordance with the example techniques described above.

[0116] In response to a determination that the sensed physiological parameter values satisfy the threshold parameter value (“YES” branch of step 708), system 100 may sense physiological parameter values over a time period (e.g., a following time period) in the sensing mode (702). In response to a determination that the sensed physiological parameter values do not satisfy the threshold parameter value (“NO” branch of step 708), system 100 may sense physiological parameter values over a time period (e.g., a following time period) in the second sensing mode (706). System 100 may continue to monitor physiological parameter values in accordance with steps 702-708 until system 100 receives an instruction to pause or terminate the sensing of physiological parameter values and / or to sense physiological parameter values in accordance with a specific sensing modeand / or sensing parameters selected by an operator (e.g., by clinician 130, patient 102, and / or one or more other individuals).

[0117] While FIG. 7 is primarily described herein with respect to two sensing modes 614 and a single threshold parameter value (e.g., threshold condition 612), system 100 may perform the techniques described herein to compare sensed physiological parameter values against two or more different threshold parameter values and switch between three or more sensing modes based on the comparison.

[0118] FIG. 8 is a flowchart illustrating another example process of monitoring one or more physiological parameters. While FIG. 8 is primarily described herein with respect to blood pressure 604 of patient 102 and threshold condition 612, the example process illustrated in FIG. 8 may be applied to other physiological parameters and threshold conditions described herein. In addition, while FIG. 8 illustrates a plurality of steps in a first order, the devices, systems, and methods described herein may apply the plurality of steps illustrated in FIG. 8 in any other order.

[0119] System 100 may sense physiological parameter values over a time period in a first sensing mode (702). System 100 may perform step 702 as previously described above with respect to FIG. 7. System 100 may temporarily sense physiological parameter values in a second sensing mode (802). System 100 (e.g., processing circuitry 302, processing circuitry 420, health monitoring application 410, HMS 116, and / or physiological parameter monitoring service 512 of system 100) may cause IMD 104 to temporarily sense physiological parameter values (e.g., values 610) in the second sensing mode independent of any other determinations, e.g., as described above with respect to FIG. 7. system 100 may cause IMD 104 to temporarily switch to the second sensing mode for a number of time periods (e.g., for one time period, for two time periods) to increase sensing frequency of IMD 104 during the number of time periods. Increasing the sensing frequency under the second sensing mode e.g., to verify the accuracy of the sensed physiological parameter values and / or to monitor variations of the sensed physiological parameter values over time. In some examples, system 100 is configured to temporarily adjust one or more sensing parameters of the first sensing mode (e.g., temporarily increasing the sensing frequency of the first sensing mode) instead of temporarily causing IMD 104 to sensing in a different sensing mode (e.g., the second sensing mode). The increased sensing frequency may increase a number of detection occurrences and / ordetection windows within each time window of a time period. For example, temporarily increasing the sensing frequency causes IMD 104 to temporarily sense physiological parameter values more than once per time window (e.g., up to four times, five or more times). Witihn each time window, the detection occurrences and / or detection windows may be evenly distributed, randomly distributed, and / or biased towards or away from specific portions of the time window (e.g., daylight hours, nighttime hours).

[0120] In some examples, system 100 causes IMD 104 to temporarily switch to the second sensing mode based on a determination that IMD 104 has been sensing physiological parameter values in the first sensing mode for at least a threshold number of consecutive time periods (e.g., at least two periods, at least five periods). In some examples, system 100 causes IMD 104 to temporarily switch to the second sensing mode based on a determination that a number of time periods (e.g., pre-determined number of time periods, randomly selected number of time periods) has elapsed, e.g., since a prior temporary switch to the second sensing mode. In some examples, system 100 causes IMD 104 to temporarily switch to the second sensing mode in response to instructions to do so from patient 102 (e.g., via patient computing device 106), clinician 130 (e.g., via clinician computing device 128), and / or one or more other individuals.

[0121] System 100 may determine whether at least a threshold amount or percentage of physiological parameter values sensed in the second sensing mode satisfies a threshold parameter value (804). System 100 may compare sensed physiological parameter values during the temporary application of the second sensing mode and / or sensing parameter adjustments to one or more threshold conditions (e.g., the threshold parameter value). System 100 may determine whether the one or more threshold conditions are satisfied (e.g., whether at least the threshold amount or percentage of physiological parameter values sensed in the second sensing mode satisfies the threshold parameter value) in accordance with the example processes previously described herein, e.g., with respect to FIG. 7.

[0122] Based on a determination that at least the threshold amount or percentage of physiological parameter values sensed in the second sensing mode satisfy the threshold parameter value (“YES” branch of step 804), system 100 may continue to sense physiological parameter values over a time period (e.g., a following time period) in the first sensing mode (702). Based on a determination that less than the threshold amount orpercentage of physiological parameter values sensed in the second sensing mode satisfy the threshold parameter value (“NO” branch of step 804), system 100 may adjust the sensing mode from the first sensing mode to the second sensing mode (806). System 100 may adjust the sensing mode to the second sensing mode in accordance with one or more of the example processes previously described herein.

[0123] System 100 may sense physiological parameter values over a time period (e.g., a following time period in the second sensing mode (706), e.g., in accordance with the example processes previously described herein, e.g., with respect to FIG. 7. After the conclusion of each time period, system 100 may determine whether at least a threshold amount or percentage of physiological parameter values sensed in the second sensing mode (e.g., during the concluded time period) satisfies a threshold parameter value (804). System 100 may iteratively perform steps 702, 706, and 802-806 over subsequent periods to switch between different sensing modes and / or sensing parameter values as needed.

[0124] While the examples in this disclosure are described primarily with reference to physiological parameter being blood pressure 604 and corresponding threshold conditions, each example may be similarly applied to every other physiological parameter and corresponding threshold condition described herein. In addition, while the examples in this disclosure primarily describe adjust sensing modes and / or sensing parameters for monitoring of a physiological parameter based on prior sensed values for the same physiological parameter, the examples may be applied to adjust sensing modes and / or sensing parameter for monitoring a first physiological parameter based on prior sensed values for a different physiological parameter. In some examples, system 100 may adjust sensing modes and / or sensing parameters for monitoring parameters corresponding to onset of sleep apnea based on sensed tissue impedance values, sensing modes and / or sensing parameters for monitoring posture and / or movement of the body of patient 102 based on sensed tissue impedance values, etc. As such, the examples in this disclosure may be applied to adjust sensing modes and / or sensing parameters for any of the physiological parameters described herein based on prior sensing values for any of the physiological parameters described herein, including the same physiological parameters.

[0125] For aspects implemented in software, at least some of the functionality ascribed to the systems and devices described in this disclosure may be embodied as instructions on a computer-readable storage medium such as RAM, DRAM, SRAM, magnetic discs,optical discs, flash memories, or forms of EPROM or EEPROM. The instructions may be executed to support one or more aspects of the functionality described in this disclosure.

[0126] In addition, in some aspects, the functionality described herein may be provided within dedicated hardware and / or software modules. Depiction of different features as modules or units is intended to highlight different functional aspects and does not necessarily imply that such modules or units must be realized by separate hardware or software components. Rather, functionality associated with one or more modules or units may be performed by separate hardware or software components, or integrated within common or separate hardware or software components. Also, the techniques could be fully implemented in one or more circuits or logic elements. The techniques of this disclosure may be implemented in a wide variety of devices or apparatuses, including an IMD, an external programmer, a combination of an IMD and external programmer, an integrated circuit (IC) or a set of ICs, and / or discrete electrical circuitry, residing in an IMD and / or external programmer.

[0127] The following is a non-limiting list of examples that are in accordance with one or more aspects of this disclosure.

[0128] Example 1: a system comprising: sensing circuitry configured to sense physiological parameter values from a patient via one or more sensors; and processing circuitry coupled to the sensing circuitry, the processing circuitry being configured to: cause the sensing circuitry to sense a first plurality of physiological parameter values over a first time period in a first sensing mode; receive the first plurality of physiological parameter values from the sensing circuitry; compare each physiological parameter value of the first plurality of physiological parameter values against a threshold parameter value; in response to determining that at least a threshold amount of physiological parameter values of the first plurality of physiological parameter values satisfies the threshold parameter value, cause the sensing circuitry to sense a second plurality of physiological parameter values over a second time period in the first sensing mode, and in response to determining that less than the threshold amount of physiological parameter values of the first plurality of physiological parameter values satisfy the threshold parameter value, cause the sensing circuitry to sense the second plurality of physiological parameter values over the second time period in a second sensing mode, wherein the second sensing mode is different from the first sensing mode.

[0129] Example 2 : the system of example 1, wherein the processing circuitry is further configured to: receive the second plurality of physiological parameters from the sensing circuitry; compare each physiological parameter value of the second plurality of physiological parameter values against the threshold parameter value; in response to determining that at least the threshold amount of physiological parameter values of the second plurality of physiological parameter values satisfies the threshold parameter value, cause the sensing circuitry to sense a third plurality of physiological parameter values over a third time period in the first sensing mode, and in response to determining that less than the threshold amount of physiological parameter values of the second plurality of physiological parameter values satisfy the threshold parameter value, cause the sensing circuitry to sense the third plurality of physiological parameter values over the third time period in the second sensing mode.

[0130] Example 3 : the system of any of examples 1 or 2, wherein each of the first time period and the second time period comprises a plurality of time windows, wherein in the first sensing mode, the processing circuitry is configured to cause the sensing circuitry to sense physiological parameter values for a first number of times across each time window of the first time period, and wherein in the second sensing mode, the processing circuitry is configured to cause the sensing circuitry to sense physiological parameter values for a second number of times across each time window of the second time period.

[0131] Example 4 : the system of example 3, wherein a duration of one or more of the first time period or the second time period is up to one month.

[0132] Example 5: the system of any of examples 3 and 4, wherein a duration of each time window of the plurality of time windows is up to 24 hours.

[0133] Example 6: the system of any of examples 3-5, wherein the first number of times is one time every time window.

[0134] Example 7 : the system of any of examples 3-6, wherein the second number of times is up to four times every time window.

[0135] Example 8: the system of example 7, wherein the second number of times are evenly distributed across a duration of the respective time window.

[0136] Example 9: the system of any of examples 3-8, wherein the second number of times is greater than the first number of times.

[0137] Example 10: the system of any of examples 1-9, wherein the physiological parameter comprises blood pressure of the patient.

[0138] Example 11: the system of example 10, wherein the threshold parameter value comprises a threshold blood pressure measurement of 130 mm Hg.

[0139] Example 12: the system of any of examples 10 or 11, wherein the one or more sensors comprises an optical blood pressure sensor.

[0140] Example 13: the system of any of examples 1-12, wherein the threshold amount comprises a threshold percentage, and wherein the threshold percentage is 80 percent.

[0141] Example 14: the system of any of examples 1-13, wherein to determine that at least the threshold amount of physiological parameter values of the first plurality of physiological parameter values satisfies the threshold parameter value, the processing circuitry is configured to determine that each value of at least the threshold amount of physiological parameter values is greater than or equal to the threshold parameter value.

[0142] Example 15: the system of any of examples 1-14, wherein to determine that at least the threshold amount of physiological parameter values of the first plurality of physiological parameter values satisfies the threshold parameter value, the processing circuitry is configured to determine that each value of at least the threshold amount of physiological parameter values is less than or equal to the threshold parameter value.

[0143] Example 16: the system of any of examples 1-15, further comprising an implantable medical device (IMD), and wherein the processing circuitry, the sensing circuitry, and the one or more sensors are disposed within the IMD.

[0144] Example 17: the system of example 16, wherein the IMD comprises an insertable cardiac monitor comprising: a housing configured for subcutaneous implantation in the patient, the housing having a length between 40 millimeters (mm) and 60 mm between a first end and a second end, a width less than the length, and a depth less than the width, wherein the processing circuitry and the sensing circuitry are disposed within the housing, and wherein the one or more sensors are disposed on or within the housing.

[0145] Example 18: the system of any of examples 1-17, wherein the processing circuitry is configured to: receive a clinician input indicating a selected sensing mode, the selected sensing mode being one of the first sensing mode or the second sensing mode;and in response to the clinician input, cause the sensing circuitry to sense physiological parameters in the selected sensing mode.

[0146] Example 19: the system of any of examples 1-18, wherein the processing circuitry is configured to: receive information indicative of a change in patient medication information; and in response to the information, cause the sensing circuitry to sense physiological parameter values in the second sensing mode.

[0147] Example 20: a method for operating a medical system to sense physiological parameter values from a patient, the method comprising: causing, by processing circuitry of the medical system, sensing circuitry of the medical system to sense a first plurality of physiological parameter values from the patient over a first time period via one or more sensors coupled to the sensing circuitry; comparing, by the processing circuitry, each physiological parameter value of the first plurality of physiological parameter values against a threshold parameter value; in response to determining that at least a threshold amount of physiological parameter values of the first plurality of physiological parameter values satisfy the threshold parameter value, causing, by the processing circuitry, the sensing circuitry to sense a second plurality of physiological parameter values over a second time period in the first sensing mode; and in response to determining that less than the threshold amount of physiological parameter values of the first plurality of physiological parameter values satisfy the threshold parameter value, causing, by the processing circuitry, the sensing circuitry to sense the second plurality of physiological parameter values over the second time period in a second sensing mode, wherein the second sensing mode is different from the first sensing mode.

[0148] Example 21: the method of example 20, further comprising: comparing, by the processing circuitry, each physiological parameter value of the second plurality of physiological parameter values against the threshold parameter value; in response to determining that at least a threshold amount of physiological parameter values of the second plurality of physiological parameter values satisfy the threshold parameter value, causing, by the processing circuitry, the sensing circuitry to sense a second plurality of physiological parameter values over a third time period in the first sensing mode; and in response to determining that less than the threshold amount of physiological parameter values of the second plurality of physiological parameter values satisfy the threshold parameter value, causing, by the processing circuitry, the sensing circuitry to sense thethird plurality of physiological parameter values over the second time period in the second sensing mode.

[0149] Example 22: the method of any of examples 20 and 21, wherein each of the first time period and the second time period comprises a plurality of time windows, wherein causing the sensing circuitry to sense the first plurality of physiological parameter values in the first sensing mode comprises causing, by the processing circuitry, the sensing circuitry to sense physiological parameter values for a first number of times across each time window of the first time period, and wherein causing the sensing circuitry to sense the second plurality of physiological parameter values in the second sensing mode comprises causing, by the processing circuitry, the sensing circuitry to sense physiological parameter values for a second number of times across each time window of the second time period, the second number of times being different from the first number of times.

[0150] Example 23: the method of example 22, wherein a duration of one or more of the first time period or the second time period is up to one month.

[0151] Example 24: the method of any of examples 22 and 23, wherein a duration of each time window of the plurality of time windows is up to 24 hours.

[0152] Example 25: the method of any of examples 22-24, wherein the first number of times is one time every time window.

[0153] Example 26: the method of any of examples 22-25, wherein the second number of times is up to four times every time window.

[0154] Example 27: the method of example 26, wherein the second number of times are evenly distributed across a duration of the respective time window.

[0155] Example 28: the method of any of examples 22-27, wherein the second number of times is greater than the first number of times.

[0156] Example 29: the method of any of examples 20-28, wherein the physiological parameter comprises blood pressure of the patient.

[0157] Example 30: the method of example 29, wherein the threshold parameter value comprises a threshold blood pressure measurement of 130 mm Hg.

[0158] Example 31: the method of any of examples 20-30, wherein the one or more sensors comprises an optical blood pressure sensor.

[0159] Example 32: the method of any of examples 20-31, wherein the threshold amount comprises a threshold percentage, and wherein the threshold percentage is 80 percent.

[0160] Example 33: the method of any of examples 20-32, wherein determining that at least the threshold amount of physiological parameter values of the first plurality of physiological parameter values satisfies the threshold parameter value comprises determining, by the processing circuitry, that each value of at least the threshold amount of physiological parameter values is greater than or equal to the threshold parameter value.

[0161] Example 34: the method of any of examples 20-33, wherein determining that at least the threshold amount of physiological parameter values of the first plurality of physiological parameter values satisfies the threshold parameter value comprises determining, by the processing circuitry, that each value of at least the threshold amount of physiological parameter values is less than or equal to the threshold parameter value.

[0162] Example 35: the method of any of examples 20-34, further comprising: receiving, by the processing circuitry, a clinician input indicating a selected sensing mode, the selected sensing mode being one of the first sensing mode or the second sensing mode; and in response to the clinician input, causing, by the processing circuitry, the sensing circuitry to sense physiological parameters in the selected sensing mode.

[0163] Example 36: the method of any of examples 20-35, further comprising: receiving, by the processing circuitry, information indicative of a change in patient medication information; and in response to the information, causing, by the processing circuitry, the sensing circuitry to sense physiological parameter values in the second sensing mode.

[0164] Example 37: a computer-readable medium comprising instructions that, when executed, causes processing circuitry of a medical system to perform the method of any of examples 20-36.

[0165] Example 38: a system comprising: sensing circuitry configured to sense physiological parameter values from a patient via one or more sensors; and processing circuitry coupled to the sensing circuitry, the processing circuitry being configured to: cause the sensing circuitry to sense physiological parameter values over a first time period at a first frequency across the first time period; compare each sensed physiological parameter value over the first time period against a threshold parameter value; in responseto determining that at least a threshold amount of sensed physiological parameter values over the first time period satisfies the threshold parameter value, cause the sensing circuitry to sense physiological parameter values over a second time period at the first frequency, and in response to determining that less than the threshold amount of sensed physiological parameter values over the first period satisfy the threshold parameter value, cause the sensing circuitry to sense physiological parameter values over the second time period at a second frequency within the second time period.

[0166] Example 39: the system of example 38, wherein the processing circuitry is further configured to: compare each sensed physiological parameter value over the second time period against the threshold parameter value; in response to determining that at least a threshold amount of sensed physiological parameter values over the second time period satisfies the threshold parameter value, cause the sensing circuitry to sense physiological parameter values over a third time period at the first frequency, and in response to determining that less than the threshold amount of sensed physiological parameter values over the second period satisfy the threshold parameter value, cause the sensing circuitry to sense physiological parameter values over the third time period at the second frequency.

[0167] Example 40: the system of any of examples 38 and 39, wherein the first frequency corresponds to a first number of sensing intervals across each time window of the first time period, and wherein the second frequency corresponds to a second number of sensing intervals across each time window of the second time period, wherein the second number is greater than the first number.

[0168] Example 41: the system of any of examples 38-40, wherein a duration of one or more of the first time period or the second time period is up to one month, and wherein a duration of each time window of the one or more of the first time period or the second time period is up to 24 hours.

[0169] Example 42: the system of any of examples 40 and 41, wherein to cause the sensing circuitry to sense physiological parameter values at the first frequency, the processing circuitry is configured to cause the sensing circuitry to sense physiological parameter values during one sensing interval within each time window.

[0170] Example 43: the system of example 42, wherein a start time and an end time of each sensing interval within the time window is uniform across each time window of a respective time period of the first time period or the second time period.

[0171] Example 44: the system of example 42, wherein to cause the sensing circuitry to sense physiological parameter values at the first frequency, the processing circuitry is configured to randomly determine one or more of a start time or an end time of each sensing interval, and wherein the start time and the end time of each sensing interval is different from the start time and the end time of at least one other sensing interval.

[0172] Example 45: the system of any of examples 40-44, wherein to cause the sensing circuitry to sense physiological parameter values at the second frequency, the processing circuitry is configured to sense physiological parameter values during a plurality of sensing intervals within each time window, the plurality of sensing intervals being equally distributed across the duration of the time window.

[0173] Example 46: the system of any of examples 40-45, wherein to cause the sensing circuitry to sense physiological parameter values at the first frequency, the processing circuitry is configured to sense physiological parameter values during a plurality of sensing intervals within each time window, the plurality of sensing intervals being randomly distributed across the duration of the time window.

[0174] Example 47: the system of example 46, wherein for each time window, the processing circuitry is configured to randomly select a number of sensing intervals within the plurality of sensing intervals for the time window.

[0175] Example 48: the system of any of examples 38-47, wherein the physiological parameter comprises blood pressure of the patient.

[0176] Example 49: the system of example 48, wherein the threshold parameter value comprises a threshold blood pressure measurement of 130 mm Hg.

[0177] Example 50: the system of any of examples 48 or 49, wherein the one or more sensors comprises an optical blood pressure sensor.

[0178] Example 51: the system of any of examples 38-50, wherein the threshold amount comprises a threshold percentage, and wherein the threshold percentage is 80 percent.

[0179] Example 52: the system of any of examples 38-51, further comprising an implantable medical device (IMD), and wherein the processing circuitry, the sensing circuitry, and the one or more sensors are disposed within the IMD.

[0180] Example 53: the system of example 52, wherein the IMD comprises an insertable cardiac monitor comprising: a housing configured for subcutaneousimplantation in the patient, the housing having a length between 40 millimeters (mm) and 60 mm between a first end and a second end, a width less than the length, and a depth less than the width, wherein the processing circuitry and the sensing circuitry are disposed within the housing, and wherein the one or more sensors are disposed on or within the housing.

[0181] Example 54: the system of any of examples 38-53, wherein the processing circuitry is configured to: receive a clinician input indicating a selected sensing frequency, the selected sensing frequency being one of the first frequency or the second frequency; and in response to the clinician input, cause the sensing circuitry to sense physiological parameters at the selected sensing frequency.

[0182] Example 55: the system of any of examples 38-54, wherein the processing circuitry is configured to: receive information indicative of a change in patient medication information; and in response to the information, cause the sensing circuitry to sense physiological parameter values at the second frequency.

[0183] Various aspects of the disclosure have been described. These and other aspects are within the scope of the following claims.

Claims

WHAT IS CLAIMED IS:

1. A system comprising: sensing circuitry configured to sense physiological parameter values from a patient via one or more sensors; and processing circuitry coupled to the sensing circuitry, the processing circuitry being configured to: cause the sensing circuitry to sense a first plurality of physiological parameter values over a first time period in a first sensing mode; receive the first plurality of physiological parameter values from the sensing circuitry; compare each physiological parameter value of the first plurality of physiological parameter values against a threshold parameter value; in response to determining that at least a threshold amount of physiological parameter values of the first plurality of physiological parameter values satisfies the threshold parameter value, cause the sensing circuitry to sense a second plurality of physiological parameter values over a second time period in the first sensing mode, and in response to determining that less than the threshold amount of physiological parameter values of the first plurality of physiological parameter values satisfy the threshold parameter value, cause the sensing circuitry to sense the second plurality of physiological parameter values over the second time period in a second sensing mode, wherein the second sensing mode is different from the first sensing mode.

2. The system of claim 1, wherein the processing circuitry is further configured to: receive the second plurality of physiological parameters from the sensing circuitry; compare each physiological parameter value of the second plurality of physiological parameter values against the threshold parameter value; in response to determining that at least the threshold amount of physiological parameter values of the second plurality of physiological parameter values satisfies the threshold parameter value, cause the sensing circuitry to sense a third plurality of physiological parameter values over a third time period in the first sensing mode, and in response to determining that less than the threshold amount of physiological parameter values of the second plurality of physiological parameter values satisfy the threshold parameter value, cause the sensing circuitry to sense the third plurality of physiological parameter values over the third time period in the second sensing mode.

3. The system of any of claims 1 or 2, wherein each of the first time period and the second time period comprises a plurality of time windows, wherein in the first sensing mode, the processing circuitry is configured to cause the sensing circuitry to sense physiological parameter values for a first number of times across each time window of the first time period, and wherein in the second sensing mode, the processing circuitry is configured to cause the sensing circuitry to sense physiological parameter values for a second number of times across each time window of the second time period.

4. The system of claim 3, wherein a duration of one or more of the first time period or the second time period is up to one month.

5. The system of any of claims 3 and 4, wherein a duration of each time window of the plurality of time windows is up to 24 hours.

6. The system of any of claims 3-5, wherein the first number of times is one time every time window.

7. The system of any of claims 3-6, wherein the second number of times is up to four times every time window.

8. The system of claim 7, wherein the second number of times are evenly distributed across a duration of the respective time window.

9. The system of any of claims 3-8, wherein the second number of times is greater than the first number of times.

10. The system of any of claims 1-9, wherein the physiological parameter comprises blood pressure of the patient.

11. The system of claim 10, wherein the threshold parameter value comprises a threshold blood pressure measurement of 130 mm Hg.

12. The system of any of claims 10 or 11, wherein the one or more sensors comprises an optical blood pressure sensor.

13. The system of any of claims 1-12, wherein the threshold amount comprises a threshold percentage, and wherein the threshold percentage is 80 percent.

14. The system of any of claims 1-13, wherein to determine that at least the threshold amount of physiological parameter values of the first plurality of physiological parameter values satisfies the threshold parameter value, the processing circuitry is configured to determine that each value of at least the threshold amount of physiological parameter values is greater than or equal to the threshold parameter value.

15. The system of any of claims 1-14, wherein to determine that at least the threshold amount of physiological parameter values of the first plurality of physiological parameter values satisfies the threshold parameter value, the processing circuitry is configured to determine that each value of at least the threshold amount of physiological parameter values is less than or equal to the threshold parameter value.

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