Implantable medical device for diaphragm stimulation

Abstract

A system comprising: a first electrode; a second electrode; signal generation circuitry coupled to the first electrode and the second electrode; and processing circuitry configured to: determine a timing of one or more events of a heart of a patient; determine, based on the timing of the one or more events, a first stimulation timing for a first stimulation signal; determine, based on the timing of the one or more events, a second stimulation timing for a second stimulation signal, the second stimulation signal being different from the first stimulation signal; cause the signal generation circuitry to deliver, based on the first simulation timing, the first stimulation signal to a heart of a patient via the first electrode; and cause the signal generation circuitry to deliver, based on the second stimulation timing, the second stimulation signal to a diaphragm of the patient via the second electrode.

Description

Attorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1IMPLANTABLE MEDICAL DEVICE FOR DIAPHRAGM STIMULATION

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 708,079, filed October 16, 2024, the entire content of which is incorporated herein by reference.TECHNICAL FIELD

[0002] The disclosure relates to medical devices, and more particularly to medical devices for delivery of medical therapy to tissue of a patient.BACKGROUND

[0003] Various types of implantable medical devices (IMDs) have been implanted for treating or monitoring one or more conditions of a patient. Such IMDs may be adapted to monitor or treat conditions or functions relating to heart, muscle, nerve, brain, stomach, endocrine organs or other organs and their related functions. Such IMDs may be associated with leads that position electrodes at a desired location or may be leadless with electrodes integrated with and / or attached to the device housing. These IMDs may have the ability to wirelessly transmit data either to another device implanted in the patient or to another instrument located externally of the patient, or both.SUMMARY

[0004] In general, this disclosure is directed to implantable medical devices (IMDs) configured to deliver medical therapy (e.g., electrical stimulation and / or pacing signals) to tissue of a diaphragm of a patient.

[0005] A heart of a patient may exhibit reduced cardiac function (e.g., heart failure), which may increase the difficulty for the heart to sufficiently pump blood out of the heart to other regions of the body of the patient within each cardiac cycle. Assistance in the pumping functionality of the heart may improve cardiac function of the heart and / or the quality of life of the patient. Stimulation of the diaphragm may induce movement (e.g., contraction, expansion) of the diaphragm, which may apply a mechanical force on one or more chambers of the heart and / or on one or more major vessels connected to the heart. The mechanical force may mechanically facilitate the pumping action of the heart. A medical device system may stimulate the diaphragm instead of or in addition to stimulation of cardiac tissue of the heart to facilitate the pumping action by the heart.Atorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1

[0006] A medical device system described herein may include one or more implantable medical devices (IMDs) configured to deliver a stimulation signal to one or more of the diaphragm or the heart of the patient, e.g., to assist in the pumping action by the heart within each cardiac cycle. The medical device system may time stimulation of the diaphragm to coincide with one or more cardiac events within the heart (e.g., closure / opening of one or more cardiac valves, between a transition of the heart between a diastole phase and a systole phase of the cardiac cycle) to facilitate the pumping of blood out of one or more chambers of the heart. In some examples, the medical device system includes an IMD and one or more elongated leads extending from the IMD to place electrode(s) at or around the diaphragm and / or the heart of the patient. In some examples, the medical device system includes two or more IMDs, each IMD coupling one or more electrodes to one or more of the diaphragm or the heart.

[0007] In some examples, this disclosure is directed to a system comprising: a first electrode; a second electrode, the second electrode being different from the first electrode; signal generation circuitry coupled to the first electrode and the second electrode; and processing circuitry configured to: determine a timing of one or more events of a heart of a patient; determine, based on the timing of the one or more events, a first stimulation timing for a first stimulation signal; determine, based on the timing of the one or more events, a second stimulation timing for a second stimulation signal, the second stimulation signal being different from the first stimulation signal; cause the signal generation circuitry to deliver, based on the first simulation timing, the first stimulation signal to a heart of a patient via the first electrode; and cause the signal generation circuitry to deliver, based on the second stimulation timing, the second stimulation signal to a diaphragm of the patient via the second electrode.

[0008] In some examples, this disclosure is directed to an implantable medical device (IMD) comprising: a housing; signal generation circuitry disposed within the housing; a first electrode and a second electrode electrically coupled to the signal generation circuitry; and processing circuitry disposed within the housing, the processing circuitry being configured to: determine a timing of one or more events of a heart of a patient; determine, based on the timing of the one or more events, a stimulation timing for a stimulation signal; and cause the signal generation circuitry to deliver, via the second electrode, the stimulation signal to a diaphragm of the patient based on the stimulation timing.

[0009] In some examples, this disclosure is directed to a method comprising: determining, by processing circuitry of an implantable medical device (IMD), a timing of the one or more events of a heart of a patient; determining, by the processing circuitry and based at least in part on the timing of the one or more events, a stimulation timing for a stimulation signal; and causing, by the processing circuitry, signal generation circuitry of the IMD to deliver, via an electrodeAtorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1 coupled to the IMD, the stimulation signal to the diaphragm in accordance with the stimulation timing.

[0010] In some examples, this disclosure is directed to an implantable medical device (IMD) comprising: a housing; an implantable lead extending distally from the housing, the implantable lead comprising: an elongated body extending from the housing; and an electrode disposed on a distal portion of the elongated body, the elongated body being configured to be disposed within a middle cardiac vein (MCV) of a patient; signal generation circuitry disposed within the housing and electrically coupled to the electrode; and processing circuitry disposed within the housing, the processing circuitry being configured to: determine a timing of one or more events of a heart of the patient; determine, based on the timing of the one or more events, a stimulation timing for each stimulation signal of one or more stimulation signals; and cause the signal generation circuitry to deliver, via the electrode, at least one stimulation signal of the one or more stimulation signals to one or more of a diaphragm or a heart of the patient based at least in part on the stimulation timings.

[0011] This 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 methods and systems described in detail within the accompanying drawings and description below.BRIEF DESCRIPTION OF DRAWINGS

[0012] The details of one or more examples of this disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of this disclosure will be apparent from the description and drawings, and from the claims.

[0013] FIG. 1 is a conceptual diagram illustrating an example medical device system for delivery of stimulation to a diaphragm of a patient, in accordance with one or more aspects of this disclosure.

[0014] FIG. 2A is a perspective diagram illustrating an example configuration of the medical device system of FIG. 1.

[0015] FIG. 2B is a perspective diagram illustrating another example configuration of the medical device system of FIG. 1.

[0016] FIG. 3 is a block diagram illustrating an example configuration of an example device of any of FIGS. 1-2B.

[0017] FIG. 4 is a plot diagram illustrating an example timing of a stimulation signal delivered by an example medical device system of any of FIGS. 1-3.Atorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1

[0018] FIG. 5A is a perspective diagram illustrating an example configuration of an electrode of any of FIGS, l^k

[0019] FIG. 5B is a perspective diagram illustrating another example configuration of an electrode of any of FIGS. 1—4.

[0020] FIG. 6 is a perspective diagram illustrating another example configuration of the medical device system of FIG. 1.

[0021] FIG. 7 is a perspective diagram illustrating another example configuration of the medical device system of FIG. 1.

[0022] FIG. 8 is a perspective diagram illustrating another example configuration of the medical device system of FIG. 1.

[0023] FIG. 9 is a perspective diagram illustrating another example configuration of the medical device system of FIG. 1.

[0024] FIG. 10 is a flowchart illustrating an example process for delivering stimulation signals to a diaphragm of a patient via an example medical device system of any of FIGS. 1-9.DETAILED DESCRIPTION

[0025] In general, this disclosure is directed to medical device system for delivery of stimulation signals to a diaphragm of a patient. The delivery of the stimulation signals to the diaphragm may cause the diaphragm to contract and facilitate the pumping of blood out of the heart of the patient. The medical device system may also be configured to deliver stimulation signals (e.g., pacing signals) to the heart of the patient, e.g., to further facilitate the pumping of blood out of the heart.

[0026] FIG. 1 is a conceptual diagram illustrating an example medical device system 100 (alternatively referred to herein as “system 100”) for delivery of stimulation to a diaphragm 106 of a patient 102, in accordance with one or more aspects of this disclosure. System 100 may include implantable medical device (IMD) 108. IMD 108 may include processing circuitry 110, signal generation circuitry 114, and memory 112. System 100 may further include one or more elongated leads 116 extending from IMD 108, and electrodes 118, 120 disposed on elongated lead(s) 116 and coupled to signal generation circuitry 114 of IMD 108.

[0027] Heart 104 and diaphragm 106 are retained within an inner thoracic cavity of patient 102. Heart 104 of patient 102 is retained within a pericardium of patient 102. The pericardium is attached to diaphragm 106 and may move with the contraction and expansion of diaphragm 106 during the respiration cycle of patient 102. For example, the pericardium may move up and place heart 104 in a relatively more horizontal orientation in response to expansion of diaphragm 106 during expiration by patient 102. Similarly, the pericardium may move down and place heart 104Atorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1 in a relatively more vertical orientation in response to contraction of diaphragm 106 during inspiration by patient 102. The movement of diaphragm 106 may thus facilitate pumping of blood through heart 104.

[0028] Movement of diaphragm 106 may facilitate one or more aspects of cardiac function of heart 104. The one or more aspects may include, but are not limited to, facilitating venous and lymph return through heart 104, modulating afterload hemodynamics of one or more chambers of heart 104 (e.g., of a left ventricle of heart 104), modulating a pericardial pressure within heart 104, regulating a tone of an autonomous nervous system of patient 102, and / or improving a baroreflex sensitivity of patient 102. Movement of diaphragm 106 during a respiration cycle may facilitate the pumping of blood through heart 104 and / or through a pulmonary venous system of patient 102. The movement of diaphragm 106 during respiration may affect the intrathoracic pressure within patient 102, which may improve hemodynamics and cardiac loading within heart 104.

[0029] During the inspiration phase of the respiration cycle, the contraction of diaphragm 106 reduces intrathoracic pressure and increases intraabdominal pressure within patient 102. The pressure gradient between the intrathoracic pressure and the intraabdominal pressure may increase the blood flow through the venous return to the right atrium of heart 104. The reduction of intrathoracic pressure may increase the pressure gradient between the right atrium and the right ventricle of heart 104, which may increase myocardial stretch and / or right-side stroke volume within heart 104.

[0030] During the expiration phase of the respiration cycle, the expansion of diaphragm 106 increases intrathoracic pressure and reduces intraabdominal pressure, which may reduce rightside stroke volume and increase left-side stroke volume with heart 104 (e.g., an increase in a left ventricle stroke volume in heart 104).

[0031] As illustrated in FIG. 1, IMD 108 may deliver stimulation signals to one or more of heart 104 or diaphragm 106 (e.g., via electrodes 120 and 118, respectively) to improve the pumping function of heart 104. While FIG. 1 illustrates electrodes 118, 120 as being coupled to IMD 108 via a single elongated lead 116, electrodes 118, 120 may be disposed on separate elongated leads 116 and / or on separate IMDs (e.g., on separate leaded or leadless IMDs). Electrodes 118, 129 may be placed at or around diaphragm 106 and / or cardiac tissue of heart 104 through the thoracic cavity of patient 102, e.g., as illustrated in FIG. 1, or transvenously through vasculature of patient 102.

[0032] Processing circuitry 110 may transmit instructions to signal generation circuitry 114 to cause signal generation circuitry 114 to generate and transmit stimulation signals to heart 104 and / or diaphragm 106 via electrodes 120, 118. Delivery of the stimulation signals to diaphragmAtorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1 106 may induce a contraction of diaphragm 106. In some examples, delivery of the stimulation signals to diaphragm 106 (e.g., to phrenic nerves coupled to diaphragm 106) may induce the patient 102 to inspirate and naturally contract diaphragm 106. System 100 may modulate intrathoracic pressure within patient 102 by delivering stimulation signals to diaphragm 106, e.g., to improve cardiac function and pumping of heart 104. For example, system 100 may stimulate diaphragm 106 at selected times during the cardiac cycle to increase left-side stroke volume and / or right-side stroke volume during certain portions of the cardiac cycle and / or to increase blood flow into or out of heart 104, e.g., as previously described herein.

[0033] Processing circuitry 110 may cause signal generation circuitry 114 to transmit and deliver stimulation signals to heart 104 and / or diaphragm 106 based on a predetermined stimulation timing, e.g., stored in memory 112 of IMD 108. The predetermined stimulation timing may be entered by a clinician prior to implantation of IMD 108 within patient 102, during implantation of IMD 108, and / or after implantation of IMD 108 but prior to delivery of any stimulation signals by IMD 108.

[0034] Processing circuitry 110 may receive information indicative of one or more cardiac events of heart 104 and determine and / or adjust the stimulation timing of stimulation signals based on the received information. For example, processing circuitry 100 may adjust the stimulation timing based on information received from one or more sensors (e.g., implantable sensors, wearable sensors) coupled to patient 102 and in communication with IMD 108 and / or based on information received from an external controller of system 100 (not pictured in FIG. 1). The information may include, but is not limited to, information indicative of sensed heart sounds of heart 104, electrocardiogram (ECG) signals of heart 104, or electrogram (EGM) signals of heart 104.

[0035] Processing circuitry 110 may determine and / or adjust stimulation timing of stimulation signals to be delivered to diaphragm 106 to coincide with, occur before, or occur after a cardiac event in heart 104. Cardiac events may include, but are not limited to, a closure of one or more valves of heart 104 (e.g., of one or more atrioventricular (AV) valves (i.e., mitral and tricuspid valves), of one or more semilunar valves (i.e., pulmonary and aortic valves)), an opening of one or more valves of heart 104, or a transition of heart 104 between a diastole and a systole phase during a cardiac cycle. Delivery of stimulation signals based on the timing of cardiac events may facilitate the filling of a ventricle (e.g., right ventricle) of heart 102 during a diastole phase of the cardiac cycle and the ejection of blood within the ventricle during a systole phase of the same cardiac cycle, e.g., thereby improving the pumping of blood through heart 102 during the cardiac cycle.Atorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1

[0036] In some examples, processing circuitry 110 is configured to cause signal generation circuitry 114 to deliver, via one or more of electrodes 118, 120, or one or more electrodes disposed over at least a portion of or an entirety of housing of device 108 , a pacing signal to deliver cardiopulmonary resuscitation (CPR) to patient 102. Processing circuitry 110 may determine, e.g., based on sensed signals, that patient is experiencing a cardiac condition requiring CPR (e.g., patient 102 is exhibiting pulseless electrical activity (PEA)). Processing circuitry 110 may cause signal generation circuitry 114 to deliver a pacing signal with at least a threshold pacing voltage via one or more of electrodes 118, 120, or one or more electrodes on the housing of device 108 into a substemal space of patient 102 to deliver CPR to heart 104. A Pacing signal delivered by one or more of electrodes 118, 120, or one or more electrodes on the housing of device 108 with at least the threshold pacing voltage may cause stimulation and / or contraction of thoracic muscles of patient 102, which may lead to an increase in intrathoracic pressure of patient 102. When the thoracic muscles relax (e.g., in response to the cessation of the pacing signal delivered by electrode 118, 120, or one or more electrodes on the housing of device 108), the intrathoracic pressure of patient 102 decreases, leading to a filling of the chambers of heart 104 through passive filling. Delivery of pacing signals to heart 104 and / or diaphragm 106 to induce the changes in intrathoracic pressure may cause patient 102 to experience a thoracic pump effect, e.g., thereby delivering CPR therapy to patient 102.

[0037] Electrode 118 may be configured to deliver stimulation signals to diaphragm 106 and electrode 120 may be configured to deliver stimulation signals (e.g., cardiac pacing signals, cardiac defibrillation signals) to heart 104. The characteristics of stimulations signals delivered to heart 104 and to diaphragm 106 may define different characteristics such as, but is not limited to, frequency, duration, amplitude, start time, or end time.

[0038] In the example illustrated in FIG. 1, electrode 118 may be placed in contact with an outer surface of diaphragm 106 or at least partially within the tissue of diaphragm 106. Electrode 118 may be placed next to muscle fibers of diaphragm 106 and / or next to one or more branches of a phrenic nerve extending from diaphragm 106. In some examples, electrode 118 is placed within a left inferior phrenic vein (LIPV) of patient 102. Electrode 120 may be placed within the pericardium of patient 102, within one or more chambers of heart 104 of patient 102 (e.g., a right atrium (RA) of heart 104), within a coronary sinus of patient 102, within a left subclavian vein (LSCV) of patient 102, or within a substemal space of patient 102 (e.g., around but external to the epicardium of patient 102, within the pleural space of patient 102). Within the pericardium, electrode 120 may or may not be placed in direct contact with an outer surface of heart 104, but may transmit electrical signals into cardiac tissue of heart 102 and / or sense electrical signals fromAtorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1 the cardiac tissue. System 100 may determine EGM and / or ECG signals based on the sensed electrical signals.

[0039] In some examples, IMD 108 may be coupled to a single electrode configured to perform the functions of both electrode 118 and electrode 120 as described herein. In such examples, the electrode may be disposed within the middle cardiac vein (MCV) of patient 102. IMD 108 may deliver a pacing signal via the electrode to both heart 104 and diaphragm 106, e.g., to stimulate both heart 104 and diaphragm 106 simultaneously. IMD 108 may deliver a pacing signal via the electrode to stimulate diaphragm 106 only, e.g., by delivering the pacing signal during an absolute refractory period of heart 104. In such examples, the pacing signal to diaphragm 106 may increase the intracellular calcium metabolism of patient 102, e.g., thereby providing Cardiac Contractility Modulation (CCM) therapy to patient 102. In such examples, IMD 108 may be configured to provide, via the single electrode, one or more of cardiac pacing therapy, diaphragm pacing / synchronization therapy, or CCM therapy to patient 102.

[0040] Each of electrodes 118, 120 may be coated with or otherwise retain (e.g., within a recess in the electrode) an anti-inflammatory substance. The anti-inflammatory substance may reduce changes in pacing thresholds of cardiac and / or diaphragm tissue over time, e.g., due to inflammation of the tissue. The anti-inflammatory substance may include, but is not limited to, a steroid. The anti-inflammatory substance may be disposed within a monolithic controlled release device (MCRD) disposed within one or more of electrodes 118, 120 and / or along implantable lead 116.

[0041] In some examples, IMD 108 is implanted within patient 102 (e.g., is implanted in a subcutaneous, extravascular pocket). In some examples, IMD 108 is implanted at least partially or wholly within a vasculature of patient 102 or within heart 104 of patient 102. In some examples, the components of IMD 108 may be disposed within an external device which may be coupled to an implanted elongated lead 116 and / or to one or more implanted devices containing electrodes 118, 120. In some examples, the components of IMD 108 may be disposed within two or more separate IMDs electrically coupled to heart 104 and / or diaphragm 106. In such examples, the two or more separate IMDs may be in wireless communication, e.g., to coordinate the delivery of stimulation signals to heart 104 and / or diaphragm 106.

[0042] System 100 may deliver any combination of a plurality of therapies to patient 102 (e.g., to heart 104, to diaphragm 106) via electrodes 118, 120 and / or any other electrodes and / or therapy delivery elements (e.g., defibrillation coils) connected to IMD 108. The plurality of therapies may include, but are not limited to, CCM, High-Voltage (HV) shock therapy, antitachycardia pacing (ATP) therapy, other therapies delivered by an implantable cardioverter-Atorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1 defibrillator (ICD), conduction system pacing (CSP) therapy, or diaphragm synchronized pacing (DSP) therapy, or the like.

[0043] FIG. 2A is a perspective diagram illustrating an example of system 100 of FIG. 1. System 100 A may include IMD 108, elongated lead 116 extending from proximal end 204A to distal end 204B, and one or more electrodes 120 and electrode 118 disposed along elongated lead 116. As illustrated in FIG. 2A, IMD 108 may be implanted within patient 102 and external to the intrathoracic cavity of patient 102 (i.e., outside of the ribcage of patient 102). Proximal end 204A of elongated lead 116 may be coupled to IMD 108. Elongated lead 116 may extend into the intrathoracic cavity, through or around diaphragm 106 (e.g., around an inferior surface of diaphragm 106), and into pericardium or the substemal space (e.g., outside of the pericardium) of patient 102. Distal end 204B of implantable lead 116 may be placed within the pericardium of patient 102 and around the outer surface of heart 104.

[0044] In some examples, IMD 108 is disposed external to a vasculature of patient 102, e.g., within a subcutaneous pocket on patient 102. Elongated lead 116 may extend into the vasculature and extend through the vasculature to a position proximal to diaphragm 106. For example, elongated lead 116 may extend through a middle cardiac vein and exit the vasculature at a position at or proximal to a cardiac apex of heart 104.

[0045] Elongated lead 116 may include one or more electrodes 120 and one or more electrodes 118 disposed on the same elongated body of elongated lead 116. Elongated lead 116 may position electrodes 120, 118 within an intrathoracic cavity of patient 102 (i.e., within a substemal space of patient 102). In some examples, elongated lead 116 may include one or more elongated bodies branching off from a main elongated body of elongated lead 116. In such examples, one or more electrodes 120 and / or one or more electrodes 118 may be disposed along one or more branching elongated bodies (e.g., at or around a distal portion of each branching elongated body).

[0046] Electrode(s) 120 may be configured to deliver stimulation signals to and / or sense electrical signals from heart 104 and may be disposed at or around a distal portion of elongated lead 116. The distal portion elongated lead 116 may be a portion of the elongated body of elongated lead 116 defining distal end 204B and / or disposed within the pericardium of heart 104 and / or the substemal space of patient 102. Electrode(s) 118 may be configured to deliver stimulation signals to diaphragm 106 of patient 102 and may be disposed at or around a more proximal portion of elongated lead 116, e.g., at one or more positions proximal to electrode(s) 120.

[0047] Placement of both electrode(s) 120 and electrode(s) 118 on a single elongated lead 116 may provide for several advantages. The use of a single elongated lead 116 may reduce aAtorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1 complexity of system 100 A and may allow for an easier and / or faster implantation procedure for system 100A (e.g., without requiring additional incision sites to advance additional elongated leads). The use of the single elongate lead 116 may allow for the placement of electrodes 120, 118, via a minimally invasive procedure (e.g., a purely non-intravenous procedure, extravascularly, or substemally).

[0048] Electrode 118 may be configured to deliver stimulation signals to diaphragm 106 at or around target stimulation site 202 of diaphragm 106. Target stimulation site 202 may include one or more muscle fibers of diaphragm 106 and / or one or more nerve fibers of one or more phrenic nerves 203 extending from diaphragm 106. Target stimulation site 202 may avoid one or more sensory nerves on or within diaphragm 106. In some examples, as illustrated in FIG. 2 A, elongated lead 116 extends through diaphragm 106 and places electrode 118 on a surface of diaphragm 106 or within diaphragm 106. In some examples, elongated lead 116 extends around the outer surface of diaphragm 106 and places electrode 118 on a surface of diaphragm 106 (e.g., on the superior surface of diaphragm 106, or on the inferior surface of diaphragm 106). Portions of elongated lead 116 may be directly affixed to diaphragm 106 or may be placed in contact with but not affixed to diaphragm 106 within the intrathoracic cavity or within in the intraabdominal cavity.

[0049] FIG. 2B is a perspective diagram illustrating another example configuration of the medical device system 100 of FIG. 1. System 100B illustrated in FIG. 2B is an example configuration of system 100 and may be substantially similar to system 100 A described above, aside from the elements discussed below.

[0050] System 100B may include elongated lead 116 extending from proximal end 204A to distal end 204B and coupled to IMD 108, with one or more electrodes 120 disposed on elongated lead 116. System 100B may further include a second IMD 206 coupled to diaphragm 106. Second IMD 206 may include electrode 208, which may be placed in contact with and deliver stimulation signals to diaphragm 106, e.g., in a manner similar to electrode 118. Second IMD 206 may be affixed to diaphragm 106 at or around target simulation site 202 on diaphragm 106.

[0051] IMD 206 may be separate from IMD 108. IMD 206 may be in wireless communication with IMD 108 and may deliver, via electrode 208 stimulation signals to diaphragm 106 based on the determined stimulation timing, e.g., in conjunction with the delivery of stimulation signals to heart 104 by IMD 108 via electrode(s) 120 on elongated lead 116. Electrode 208 may be a helical electrode (e.g., as illustrated in FIG. 2B), an elongated barb electrode, a button electrode, or the like. IMD 206 may be a leaded or leadless device. In some examples, where IMD 206 includes an elongated lead, electrode 208 may be disposed on the elongated lead (e.g., at or around a distal end of the elongated lead).Atorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1

[0052] FIG. 3 is a block diagram illustrating an example configuration of an example device of any of FIGS. 1-2B. As illustrated in FIG. 3, device 108 include electrodes 118 and 120, which may be configured as described with respect to FIGS. 1-2B. In some examples, device 108 may include one or more other electrodes such as, but is not limited to, electrode 208. In the example shown in FIG. 3, device 108, but is not limited to, switch circuitry 304, sensing circuitry 306, signal generation circuitry 114, sensor(s) 308, processing circuitry 110, telemetry circuitry 310, memory 112, and power source 312. The various circuitry may be, or include, programmable or fixed function circuitry configured to perform the functions attributed to respective circuitry. Memory 112 may store computer-readable instructions that, when executed by processing circuitry 110, cause device 108 to perform various functions. Memory 112 may be a storage device or other non-transitory medium. The components of device 108 illustrated in FIG. 3 may be housed within housing 302. The components illustrated in FIG. 3 may be disposed within a single device 108 or in two or more IMDs of system 100.

[0053] Signal generation circuitry 114 generates electrical stimulation signals, e.g., cardiac stimulation pulses, diaphragm stimulation or pacing signals. Switch circuitry 304 is coupled to electrodes 118, 120, and one or more return electrodes (not pictured in FIG. 3) and may include one or more switch arrays, one or more multiplexers, one or more switches (e.g., a switch matrix or other collection of switches), one or more transistors, or other electrical circuitry. Switch circuitry 304 is configured to direct stimulation signals from signal generation circuitry 114 to a selected combination of electrodes 118, 120 and one or more return electrodes, e.g., to selectively deliver stimulation pulses to cardiac tissue of heart 104 and / or to diaphragm 106. For example, switch circuitry 304 may couple electrode 118 and a return electrode to signal generation circuitry 114 to deliver a stimulation signal to diaphragm 106. In another example, switch circuitry 304 may couple electrode 120 and a return electrode to signal generation circuitry 114 to deliver a pacing signal to heart 104. The one or more return electrodes may be disposed on elongated lead 116, on a separate elongated lead from electrode 118 or electrode 120, or disposed elsewhere on or within the body of patient 102.

[0054] Switch circuitry 304 may also selectively couple sensing circuitry 306 to selected combinations of electrodes 118, 120, and / or one or more return electrodes, e.g., to selectively sense the electrical activity of heart 104 (e.g., of one or more chambers of heart 104) and / or the electrical activity of diaphragm 106. Sensing circuitry 306 may include filters, amplifiers, analog-to-digital converters, or other circuitry configured to sense cardiac electrical signals via electrodes 118, 120, and / or one or more return electrodes. Sensing circuitry 304 may be configured to detect cardiac events of heart 104, e.g., depolarizations, repolarizations (i.e., T- waves) within the cardiac electrical signals, and provide indications thereof to processingAtorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1 circuitry 310. In this manner, processing circuitry 110 may determine the timing of cardiac events (e.g., atrial and / or ventricular depolarizations, opening and / or closure of one or more cardiac valves, start and / or end of a systole phase or a diastole phase), and control the delivery of cardiac pacing to heart 104 and / or the delivery of pacing signals to diaphragm 106 based thereon. For example, processing circuitry 110 may cause signal generation circuitry 114 to delivery stimulation and / or pacing signals to one or more of heart 104 and / or to diaphragm 106 prior to, during, or following a specific cardiac event of heart 104. In some examples, processing circuitry 110 causes signal generation circuitry 114 to deliver shock signals (e.g., defibrillation signals) to heart 104 via electrode 118 and / or one or more shock elements (e.g., a shock coil) coupled to switch circuitry 304. Processing circuitry 110 may include any one or more of a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), discrete logic circuitry, or any other processing circuitry configured to provide the functions attributed to processing circuitry 110 herein which may be embodied as firmware, hardware, software or any combination thereof.

[0055] Sensor(s) 308 may include one or more sensing elements that transduce patient physiological activity to an electrical signal to sense values of a respective patient parameter. The respective patient parameter may include, but is not limited to, a heart sound of heart 104 and / or an electrical signal of heart 104. Sensor(s) 308 may include one or more accelerometers, sensing electrodes, or acoustic sensors. Sensor(s) 308 may output patient parameter values that may be used as feedback by processing circuitry 110 to control sensing and delivery of therapy by device 108.

[0056] Telemetry circuitry 310 supports wireless communication between device 108 and an external programmer (not shown in FIG. 3) or another computing device under the control of processing circuitry 110 (e.g., device 208). Processing circuitry 110 of device 108 may receive, sensed data indicating one or more parameters of patient 102 (e.g., sensed heart sounds, sensed cardiac signals) and / or stimulation parameters (e.g., timing parameter(s) for one or more pacing signals) from the external programmer and / or from one or more other computing devices. For example, processing circuitry 110 may receive a first set of timing parameters for delivery of a cardiac pacing signal to heart 104 and / or a second set of timing parameters different from the first set of timing parameters for delivery of a pacing signal to diaphragm 106. Processing circuitry 110 may provide collected data, e.g., sensed heart activity, sensed heart sounds, or other patient parameters, via telemetry circuitry 310. Telemetry circuitry 310 may accomplish communication by Bluetooth, intra-body conductance communication, radiofrequency (RF) communication techniques, e.g., via an antenna (not shown).Atorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1

[0057] Power source 312 delivers operating power to various components of device 108. Power source 312 may include a rechargeable or non-rechargeable battery and a power generation circuit to produce the operating power. Recharging may be accomplished through proximal inductive interaction between an external charger and an inductive charging coil within device 108.

[0058] FIG. 4 is a plot diagram 400 illustrating an example timing of a stimulation signal 406 delivered by an example system 100 of any of FIGS. 1-3. Plot diagram 400 illustrates systole phases 411 and diastole phases 413 of cardiac cycles of heart 104. Systole phases 411 and diastole phases 413 may be separated by the AV valves closures 412 and semilunar valves closures 414. AV valves may include the mitral valves and the tricuspid valves of heart 104. Semilunar valves may include the pulmonary valves and the aortic valves of heart 104.

[0059] Plot diagram 400 illustrates heart sounds 402, ECG / EGM signal 404, diaphragm stimulation signal 406, diaphragm movement 408, and intrathoracic pressure 410 across a cardiac cycle. Heart sounds 402 may include sounds resulting from cardiac events of heart 104 (e.g., contraction(s) of chamber(s) of heart 104, opening of valve(s) of heart 104, closure of valve(s) of heart 104, movement of blood through heart 104). Heart sounds 402 may be represent as four separate sounds S1-S4 for each cardiac cycle of heart 104.

[0060] SI may correspond to the closure of the mitral and tricuspid valves of heart 104. The closure of the mitral and tricuspid valves may occur close in time and may be represented as a single sound SI. SI may occur at the beginning of systole phase 411. S2 may correspond to the closure of the aortic and pulmonary valves of heart 104. The closure of the aortic and pulmonary valves may occur close in time and may be represented as a single sound S2. S2 may occur at or around a start of diastole phase 413. S3 may correspond to the movement of blood from the atrium and into the ventricle of heart 104. S3 may occur during diastole phase 413. S4 may correspond to a slowing of blood entering the ventricle from the atrium. S4 may occur at or around an end of diastole phase 413.

[0061] ECG signal 404 illustrates waves P-T, including a QRS complex as illustrated by the Q, R, and S waves of ECG signal 404. The QRS complex may represent ventricular depolarization, e.g., at or around a start of systole phase 411 of the cardiac cycle.

[0062] System 100 may deliver diaphragm stimulation signal 406 to diaphragm 106 to induce diaphragm movement 408, e.g., thereby affecting a change in intrathoracic pressure 410 and facilitating the pumping function of heart 104. Diaphragm stimulation signal 406 may include one or more stimulation pulses 416. Diaphragm stimulation signal 406 may be delivered once per cardiac cycle, once per two or more cardiac cycles, or two or more times per cardiac cycle. The delivery of diaphragm stimulation signal 406 to diaphragm 106 may cause diaphragm movementAtorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1 408 (e.g., expansion and / or contraction of diaphragm 106), which may in turn lead to a change in intrathoracic pressure 410. For example, as illustrated in plot diagram 400, contraction of diaphragm 106 (i.e., the downward movement in diaphragm movement 408) may lead to a reduction in intrathoracic pressure 410, and expansion of diaphragm 106 (i.e., the upward movement in diaphragm movement 408) may lead to an increase in intrathoracic pressure 410.

[0063] Diaphragm stimulation signal 406 may directly or indirectly cause diaphragm movement 408. In some examples, delivery of diaphragm stimulation signal 406 to diaphragm 106 may directly induce contraction of diaphragm 106. In some examples, deliveiy of diaphragm stimulation signal 406 to diaphragm 106 and / or to phrenic nerves coupled to diaphragm 106 may cause patient 102 to reflexively inhale, thereby causing diaphragm 106 to contract.

[0064] System 100 may deliver diaphragm stimulation signal 406 based on one or more timing parameters (alternatively referred to herein as the “timing”) of diaphragm stimulation signal 406. The timing of diaphragm stimulation signal 406 may include, but is not limited to, a start time of a first stimulation pulse 416 within diaphragm stimulation signal 406, an end time of the first stimulation pulse 416, a start time of a last stimulation pulse 416 within diaphragm stimulation signal 406, an end time of the last stimulation pulse 416, a duration from the start of the first stimulation pulse 416 to the end of the last stimulation pulse 416, or a recovery period between temporally adjacent stimulation pulses 416 within diaphragm stimulation signal 406. In some examples, the recovery period is up to 50 milliseconds (ms).

[0065] System 100 may determine, based on heart sounds 402 and / or ECG signal 404, a timing of one or more cardiac events within heart 104. The one or more cardiac events may include, but are not limited to, AV valves closure 412, opening of the AV valves, semilunar valves closure 414, opening of the semilunar valves, start of diastole phase 413, end of diastole phase 413, start of systole phase 411, or an end of systole phase 411. System 100 may adjust the timing of diaphragm stimulation signal 406 to deliver diaphragm stimulation signal 406 prior to, during, and / or following the cardiac events, e.g., to affect a specific change in intrathoracic pressure 410 during a specific portion of the cardiac cycle of heart 104. For example, as illustrated in plot diagram 400, system 100 may determine a timing of a start of systole phase 411 of the cardiac cycle based on a timing of SI of heart sounds 402 and / or a timing of the QRS complex of ECG signal 404. In some examples, system 100 determines the timing of a P-wave of the QRS complex of ECG signal 404 and determines a start of the deliver of diaphragm stimulation signal 406 to begin a threshold period of time after the P-wave. The threshold period of time may be substantially similar for a duration of a P-R interval of the QRS complex of ECG signal 404. System 100 may then adjust the timing of diaphragm stimulation signal 406 and deliver all stimulation pulses 416 of diaphragm stimulation signal 406 prior to and / or at the startAtorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1 of systole phase 411. In such examples, diaphragm stimulation signal 406 may lead to contraction of diaphragm 106 during at least a portion of systole phase 411, leading to a reduction in intrathoracic pressure 410 during at least a portion of systole phase 411. The reduction in intrathoracic pressure 410 may increase right-side stroke volume in heart 104, e.g., thereby assisting in the pumping functionality of heart 104. In some examples, system 100 may adjust the timing of diaphragm stimulation signal 406 to cause a change in intrathoracic pressure 410 and / or one or more other parameters linked to movement of diaphragm 106 during one or more other sections of the cardiac cycle, e.g., to aid in the pumping of blood by heart 104. For example, system 100 may adjust the timing of diaphragm stimulation signal 406 based on the timing of the P-wave of the QRS complex of ECG signal 404.

[0066] FIG. 5A is a perspective diagram illustrating an example configuration of electrode 118 of any of FIGS. 1-4. Electrode 118A illustrated in FIG. 5 A may be an example of electrode 118 illustrated in FIGS. 1-4 and may be substantially similar to electrode 118 previously described herein, aside from the elements discussed below.

[0067] Electrode 118A may be disposed along a length of elongated lead 116. Electrode 118A may define a disc shape with an outer surface 502. Outer surface 502 may be at least partially electrically conductive and may define an electrically conductive region of electrode 118A. Electrode 118A may be configured to deliver stimulation and / or pacing signals (e.g., diaphragm stimulation signal 406) to diaphragm 106 via the electrically conductive region on outer surface 502. When electrode 118A is coupled to diaphragm 106, outer surface 502 may be placed in contact with an outer surface of diaphragm 106 for diectional diaphragm pacing (e.g., at or around target stimulation site 202) and / or placed at least partially within the tissue of diaphragm 106.

[0068] FIG. 5B is a perspective diagram illustrating another example configuration of electrode 118 of any of FIGS. 1-4. Electrode 118B illustrated in FIG. 5 A may be an example of electrode 118 illustrated in FIGS. 1-4 and may be substantially similar to electrode 118 previously described herein, aside from the elements discussed below.

[0069] Electrode 118B may define an electrically conductive ring 504 disposed around elongated lead 116. Electrically conductive ring 504 may be coupled to elongated lead 116 via one or more struts 506. Strut(s) 506 may electrically connect ring 504 to elongated lead 116, e.g., to facilitate the transmission of stimulation and / or pacing signals (e.g., diaphragm stimulation signal 106) from device 108 to diaphragm 106. In some examples, ring 504 may be disposed along elongated lead 116 and / or may be coupled to elongated lead 116 without struts 506. In such examples, ring 504 may be disposed on a second elongated lead extending from elongated lead 116.Atorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1

[0070] Ring 504 and / or strut(s) 506 may be formed from a shape memory material including, but are not limited to, nitinol. Ring 504 may be formed from an electrically conductive material or may be at least partially coated with an electrically conductive material. Electrode 118B may transition between a collapsed configuration and an expanded configuration, e.g., as illustrated in FIG. 5B. During delivery of elongated lead 116, electrode 118B may be maintained in the collapsed configuration against elongated lead 116 via a guide member (e.g., a guide sheath). Electrode 118B may be radially expanded into the expanded configuration at or around target stimulation site 202 to place at least a portion of ring 504 in contact with an outer surface of and / or inside diaphragm 106, e.g., for delivery of stimulation and / or pacing signals to diaphragm 106. In the collapsed configuration, electrode 118B may define a radially collapsed shape. In the expanded configuration, electrode 118B may transition from the radially collapsed shape into a more radially expanded shape. The radially expanded shape may be similar to a circular or oval shape.

[0071] FIG. 6 is a perspective diagram illustrating another example configuration of system 100 of FIG. 1. In the example illustrated in FIG. 6, system 100 may include IMD 108 and a plurality of leads 601, 602. A distal end of lead 601 may be disposed within LIPV 606 of patient 102. A distal end of lead 602 may be implanted within a chamber (e.g., within RA) of heart 104.

[0072] Lead 601 may include, but is not limited to, a high voltage (HV) lead. Lead 601 may include one or more electrodes (e.g., electrode 118) at or around the distal end of lead 601. Lead 601 may be advanced through vasculature of patient 102 (e.g., from a transcutaneous pocket in patient 102 containing IMD 108) into LIPV 606. Lead 601 may place the one or more electrodes in contact with a vessel wall of LIPV 606. IMD 108 may transmit a stimulation signal to diaphragm 106 and / or to phrenic nerves 203 (not pictured in FIG. 6) via electrode(s) (e.g., electrode 118) on lead 601. IMD 108 may deliver a diaphragm stimulation therapy (e.g., DSP therapy) via electrode(s) on lead 601.

[0073] Lead 602 may be implanted within a chamber of heart 104 at a target implant site 604. Target implant site 604 may be at or around a Triangle of Koch (ToK) of heart 104. Lead 602 may include electrode 120 at or around a distal end of lead 602. Electrode 120 may be a button electrode, a helical electrode, or the like. When implanted, lead 602 may place electrode 120 within cardiac tissue of heart 104 at or around target implant site 604. IMD 108 may transmit a stimulation signal (e.g., a cardiac pacing signal) to and / or sense cardiac signals from cardiac tissue via electrode 120. IMD 108 may deliver CSP and / or ATP via electrode 120.

[0074] The configuration illustrated in FIG. 6 may avoid passing lead(s) through a tricuspid valve (TV) of heart 104 into a right ventricle (RV) of heart 102, which may reduce TV dysfunction and / or complication (e.g., TV regurgitation).Atorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1

[0075] FIG. 7 is a perspective diagram illustrating another example configuration of medical device system 100 of FIG. 1. In the example illustrated in FIG. 7, system 100 may include IMD 108 and a plurality of leads 601, 702. A distal end of lead 601 may be disposed within LIPV 606 of patient 102, e.g., in a manner previously described herein with respect to FIG. 6. A distal end of lead 702 may be implanted within a coronary sinus (CS) 704 of patient 102.

[0076] Lead 702 may include one or more electrodes 120 placed along an elongated body of lead 702. One or more electrodes 120 may be placed within CS 704 at or around an orifice of CS 704. IMD 108 may deliver a stimulation signal (e.g., of CSP) via electrode(s) 120 on lead 702, e.g., at or around the orifice of CS 704. In some examples, one or more of electrodes 120 on lead 702 are disposed within the left atrium (LA) of heart 104 and may sense signals from LA of heart 104 via the one or more electrodes 120.

[0077] Lead 702 may include a defibrillation shock coil disposed along the elongated body of lead 702. In such examples, IMD 108 may deliver a defibrillation shock signal to heart 104 along a shock vector extending from lead 601 to lead 702.

[0078] FIGS. 6 and 7 illustrate non-limiting examples of system 100. In some examples, electrode(s) 120 on lead 602 or lead 702 may be implanted elsewhere within heart 104, e.g., at least partially within the septum of heart 104.

[0079] FIG. 8 is a perspective diagram illustrating another example configuration of medical device system 100 of FIG. 1. In the example illustrated in FIG. 8, system 100 may include IMD 802 and a plurality of elongated bodies 804, 806 extending from IMD 802. A first elongated body 804 may be disposed within a left subclavian vein 808 of patient 102. A second elongated body 806 may be disposed within LIPV 606 of patient 102.

[0080] IMD 802 may be an example of IMD 108 as illustrated in FIGS. 1-7. IMD 802 may be a leadless IMD. The electronic components of IMD 802 may be disposed within one or more elongated housing portions. The elongated housing portion(s) of IMD 802 may be at least partially disposed within one or more chambers of heart 104 (e.g., within RA of heart 104, as illustrated in FIG. 8).

[0081] First elongated body 804 may be disposed within left subclavian vein 808. First elongated body 804 may include one or more sensing and / or signal delivery elements including, but are not limited to, electrode 120, a HV defibrillation shock coil, or the like. Second elongated body 806 may be disposed within LIPV 606, e.g., in a manner similar to lead 601 as illustrated and described with respect to FIGS. 6-7. Electrode 118 is disposed on second elongated body 806 and may be positioned within LIPV 606, e.g., as previously described herein.

[0082] Elongated bodies 804, 806 may be affixed within the respective blood vessels via active and / or passive fixation element(s). Active fixation element(s) may include, but are notAtorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1 limited to, one or more side heli(ces). Second elongated body 806 may be removably coupled to IMD 802 and may be physically and electrically coupled to IMD 802, e.g., after placement of second elongated body 806 within LIPV 606.

[0083] FIG. 9 is a perspective diagram illustrating another example configuration of the medical device system of FIG. 1. In the example illustrated in FIG. 9, system 100 may include IMD 802 and a plurality of elongated bodies 902, 806 extending from IMD 802. A first elongated body 902 may be disposed within CS 704 of patient 102. Second elongated body 806 may be disposed within LIPV 606 of patient 102.

[0084] First elongated body 902 may be disposed within left subclavian vein 808. First elongated body 902 may include one or more sensing and / or signal delivery elements including, but are not limited to, electrode 120, a HV defibrillation shock coil, or the like. The one or more sensing and / or signal delivery elements may be disposed within CS 704, e.g., as previously described herein. First elongated body 902 may be disposed within CS 704, e.g., in a manner similar to lead 702 as illustrated and described with respect to FIG. 7. Second elongated body 806 may be disposed within LIPV 606, e.g., in a manner similar to lead 601 as illustrated and described with respect to FIGS. 6-7.

[0085] FIG. 10 is a flowchart illustrating an example process for delivering stimulation signals to diaphragm 106 of patient 102 via system 100 of any of FIGS. 1-9. While FIG. 10 is primarily described with reference to system 100 of FIG. 1, the example techniques illustrated in FIG. 10 may be performed by any examples of a medical device system as described herein.

[0086] System 100 may determine a timing of one or more events of heart 104 of patient 102(1002). Event(s) of heart 104 may include cardiac event(s) of heart 104, e.g., during a course of a cardiac cycle. Cardiac event(s) may include, but is not limited to, an opening of one or more valves of heart 104 (e.g., of one or more AV valves, of one or more semilunar valves), a closure of one or more valves of heart 104, a depolarization of one or more chambers of heart 104 (e.g., of a ventricle of heart 104), a start of systole phase 411, an end of systole phase 411, a start of diastole phase 413, or an end of diastole phase 413.

[0087] Processing circuitry 110 of device 108 of system 100 may receive (e.g., from an external programmer and / or one or more other IMD of system 100) information indicative of the timing of the one or more events. The information may include, but is not limited to, heart sounds 402 of heart 104, ECG signals 404 of heart 104, EGM signals, or other cardiac signals (e.g., other cardiac electrical signals). In some examples, processing circuitry 110 determines the timing of the one or more events based on signals (e.g., cardiac electrical signals, heart sounds 402) from one or more electrodes 118, 120 and / or sensor(s) 308 coupled to processing circuitry 110.Atorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1

[0088] Processing circuitry 110 may determine the timing of cardiac event(s) based on the information and / or signals indicative of the timing of the one or more events. The timing may indicate start and / or end time(s) for subsequent cardiac events of a same type. In some examples, processing circuitry 110 directly receives pre-determined timing parameter values, e.g., from an external programmer of system 100.

[0089] System 100 may determine, based on the timing of the one or more events, a timing of one or more diaphragm stimulation signals 406 (1004). Delivery of stimulation pulses 416 of diaphragm stimulation signal 406 to diaphragm 106 may cause diaphragm movement 408, which affects one or more cardiovascular parameters (e.g., intrathoracic pressure 410) affecting cardiovascular performance (e.g., cardiac pumping ability) of heart 104. For example, delivery of stimulation pulses 416 to diaphragm 106 may elicit contractions in diaphragm 106, leading to reduction in intrathoracic pressure 410 and an increase in the right-side stroke volume of heart 104, which may aid in the pumping of blood out of the ventricle by heart 104.

[0090] Delivery of diaphragm stimulation signal 406 during specific portions of the cardiac cycle (e.g., during diastole phase 413, during systole phase 411, immediately preceding diastole phase 413 or systole phase 411) may aid in the cardiac function of heart 104, e.g., by aiding the flow of blood into a chamber of heart 104, out of a chamber of heart 104, and / or between chambers of heart 104. Processing circuitry 110 of system 100 may determine, based on the timing of the one or more events, the timing of diaphragm stimulation signal 406 for delivery of stimulation pulses 416 of diaphragm stimulation signal 406 preceding, during, or following a specific cardiac event. For example, processing circuitry 110 may determine, based on the timing of one or more cardiac events (e.g., a timing of a closure of AV valves, a timing of depolarization of a ventricle of heart 104), a timing of depolarization of an atrium of heart, one or more timing parameters for diaphragm stimulation signal 406.

[0091] System 100 may deliver one or more diaphragm stimulation signals 406 to diaphragm 106 of patient 102 in accordance with the determined timing (1006). Processing circuitry 110 may cause signal generation circuitry 114 to transmit stimulation pulses 416 of diaphragm stimulation signal 406 to target stimulation site 202 on or within diaphragm 106 via one or more electrodes 118 disposed on or around diaphragm 106. In some examples, electrode(s) 118 are disposed on an elongated lead 116 connected to device 108 of system 100. In some examples, electrode(s) 118 are disposed on an IMD separate from device 108. System 100 may deliver diaphragm stimulation signal 406 to one or more of muscle fiber(s) or phrenic nerve fiber(s) of diaphragm 106. System 100 may deliver cardiac pacing signals to heart 104 alongside of or instead of diaphragm stimulation signal 406, e.g., to further aid in the pumping function of heart 104.Atorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1

[0092] It should be understood that various aspects disclosed herein may be combined in different combinations than the combinations specifically presented in the description and accompanying drawings. It should also be understood that, depending on the example, certain acts or events of any of the processes or methods described herein may be performed in a different sequence, may be added, merged, or left out altogether (e.g., all described acts or events may not be necessary to carry out the techniques). In addition, while certain aspects of this disclosure are described as being performed by a single module or unit for purposes of clarity, it should be understood that the techniques of this disclosure may be performed by a combination of units or modules associated with, for example, a medical device.

[0093] In one or more examples, the described techniques may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media may include non-transitory computer- readable media, which corresponds to a tangible medium such as data storage media (e.g., RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer).

[0094] In addition, it should be noted that system described herein may not be limited to treatment of a human patient. In alternative examples, the system may be implemented in nonhuman patients, e.g., primates, canines, equines, pigs, and felines. These other animals may undergo clinical or research therapies that may benefit from the subject matter of this disclosure.

[0095] Instructions may be executed by one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Accordingly, the term “processor” as used herein may refer to any of the foregoing structure or any other physical structure suitable for implementation of the described techniques. Also, the techniques could be fully implemented in one or more circuits or logic elements.

[0096] This disclosure describes each of the following examples.

[0097] Example 1 : a system comprising: a first electrode; a second electrode, the second electrode being different from the first electrode; signal generation circuitry coupled to the first electrode and the second electrode; and processing circuitry configured to: determine a timing of one or more events of a heart of a patient; determine, based on the timing of the one or more events, a first stimulation timing for a first stimulation signal; determine, based on the timing of the one or more events, a second stimulation timing for a second stimulation signal, the second stimulation signal being different from the first stimulation signal; cause the signal generationAtorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1 circuitry to deliver, based on the first simulation timing, the first stimulation signal to a heart of a patient via the first electrode; and cause the signal generation circuitry to deliver, based on the second stimulation timing, the second stimulation signal to a diaphragm of the patient via the second electrode.

[0098] Example 2: the system of example 1, further comprising: an implantable medical device (IMD) comprising a housing configured to retain the processing circuitry and the signal generation circuitry; and an implantable lead configured to be connected to the housing of the IMD, wherein at least one of the first electrode or the second electrode is disposed on the implantable lead.

[0099] Example 3: the system of example 2, wherein the implantable lead is configured to extend distally away from the housing of the IMD, wherein the first electrode is disposed at a first position along the length of the implantable lead, and wherein the second electrode is disposed at a second position along the length of the implantable lead, the second position being proximal to the first position.

[0100] Example 4: the system of any of examples 1-3, wherein the second electrode is configured to be disposed along an outer surface of the diaphragm.

[0101] Example 5: the system of any of examples 1-3, wherein the second electrode is configured to penetrate the diaphragm.

[0102] Example 6: the system of any of examples 1-5, wherein the second electrode is configured to be disposed at or around one or more muscle fibers of the diaphragm.

[0103] Example 7: the system of any of examples 1-6, wherein the one or more events of the heart comprises one or more of: a closure of one or more atrioventricular (AV) valves of the heart; an opening of the one or more AV valves; a closure of one or more semilunar valves of the heart; or an opening of the one or more semilunar valves.

[0104] Example 8: the system of any of examples 1-7, wherein the processing circuitry is configured to determine the timing of the one or more events based on one or more of: sensed heart sounds of the heart; an electrocardiogram (ECG) signal of the heart; or an electrogram (EGM) signal of the heart.

[0105] Example 9: the system of any of examples 1-8, wherein to determine the second stimulation timing for the second stimulation signal, the processing circuitry is configured to: determine, based on the timing of the one or more events, a subsequent closure time for one or more valves of the heart; and determine the second stimulation timing for deliveiy of the second stimulation signal prior to the subsequent closure time for the one or more valves of the heart.

[0106] Example 10: the system of example 9, wherein the one or more valves comprises mitral and tricuspid valves of the heart.Atorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1

[0107] Example 11 : the system of any of examples 9 or 10, wherein the second stimulation timing corresponds to delivery of the second stimulation signal at or prior to a ventricular contraction of the heart.

[0108] Example 12: the system of any of examples 1-8, wherein to determine, based on the timing of the one or more events, the second stimulation timing for the second stimulation signal, the processing circuitry is configured to: determine, based on the timing of the one or more events, a start time for a systole phase of a subsequent cardiac cycle of the heart; and determine the second stimulation timing for delivery of the second stimulation signal prior to the start time.

[0109] Example 13: the system of any of examples 1-12, wherein the second electrode is configured to transition between a collapsed configuration and an expanded configuration.

[0110] Example 14: the system of any of examples 1-13, further comprising: a first implantable medical device (IMD) coupled to the first electrode; and a second IMD coupled to the second electrode.

[0111] Example 15: the system of any of examples 1-14, further comprising one or more sensors coupled to the processing circuitry, wherein the processing circuitry is configured to determine the timing of the one or more events of the heart based on one or more signals sensed from the patient via the one or more sensors, and wherein the one or more sensors comprises one or more of: an accelerometer; the first electrode; the second electrode; or a sensing electrode coupled to the patient, the sensing electrode being separate from the first electrode and the second electrode.

[0112] Example 16: the system of any of examples 1-15, wherein the first stimulation signal comprises a pacing signal configured to deliver cardiopulmonary resuscitation (CPR) to the patient.

[0113] Example 17: the system of any of examples 1-16, wherein the first stimulation signal and the second stimulation signal are configured to induce a thoracic pump effect in the patient.

[0114] Example 18: the system of any of examples 1-17, wherein at least one of the first electrode or the second electrode is disposed within a middle cardiac vein (MCV) of the patient.

[0115] Example 19: the system of any of examples 1-18, wherein the second stimulation signal is configured to provide Cardiac Contractility Modulation (CCM) therapy to the patient.

[0116] Example 20: the system of any of examples 1-19, wherein the second stimulation signal is configured to cause the patient to reflexively inhale and contract the diaphragm.

[0117] Example 21 : an implantable medical device (IMD) comprising: a housing; signal generation circuitry disposed within the housing; a first electrode and a second electrode electrically coupled to the signal generation circuitry; and processing circuitry disposed within the housing, the processing circuitry being configured to: determine a timing of one or moreAtorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1 events of a heart of a patient; determine, based on the timing of the one or more events, a stimulation timing for a stimulation signal; and cause the signal generation circuitry to deliver, via the second electrode, the stimulation signal to a diaphragm of the patient based on the stimulation timing.

[0118] Example 22: the IMD of claim 21, wherein the IMD further comprises an implantable lead extending distally from the housing, the implantable lead comprising: an elongated body extending from the housing; the first electrode disposed on a distal portion of the elongated body; and the second electrode disposed on a proximal portion of the elongated body.

[0119] Example 23: the IMD of any of examples 21 or 22, wherein the second electrode is configured to be disposed along an outer surface of the diaphragm.

[0120] Example 24: the IMD of any of examples 21 or 22, wherein the second electrode is configured to penetrate the diaphragm.

[0121] Example 25: the IMD of any of examples 21-24, wherein the second electrode is configured to be disposed at or around one or more muscle fibers of the diaphragm.

[0122] Example 26: the IMD of any of examples 21-25, wherein the one or more events of the heart comprises one or more of: a closure of one or more atrioventricular (AV) valves of the heart; an opening of the one or more AV valves; a closure of one or more semilunar valves of the heart; or an opening of the one or more semilunar valves.

[0123] Example 27: the IMD of any of examples 21-26, wherein the processing circuitry is configured to determine the timing of the one or more events based on one or more of: sensed heart sounds of the heart; an electrocardiogram (ECG) signal of the heart; or an electrogram (EGM) signal of the heart.

[0124] Example 28: the IMD of any of examples 21-27, wherein to determine the stimulation timing for the stimulation signal, the processing circuitry is configured to: determine, based on the timing of the one or more events, a subsequent closure time for one or more valves of the heart; and determine the stimulation timing for delivery of the stimulation signal prior to the subsequent closure time for the one or more valves of the heart.

[0125] Example 29: the IMD of example 28, wherein the one or more valves comprises mitral and tricuspid valves of the heart.

[0126] Example 30: the IMD of any of examples 28 or 29, wherein stimulation timing corresponds to delivery of the stimulation signal at or prior to a ventricular contraction of the heart.

[0127] Example 31 : the IMD of any of examples 21-30, wherein to determine, based on the timing of the one or more events, the stimulation timing for the stimulation signal, the processing circuitry is configured to: determine, based on the timing of the one or more events, a start timeAtorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1 for a systole phase of a subsequent cardiac cycle of the heart; and determine the stimulation timing for delivery of the stimulation signal prior to the start time.

[0128] Example 32: the IMD of any of examples 21-31, wherein the second electrode is configured to transition between a collapsed configuration and an expanded configuration.

[0129] Example 33: the IMD of any of examples 21-32, further comprising one or more sensors coupled to the processing circuitry, wherein the processing circuitry is configured to determine the timing of the one or more events of the heart based on one or more signals sensed from the patient via the one or more sensors, and wherein the one or more sensors comprises one or more of: an accelerometer; the first electrode; the second electrode; or a sensing electrode coupled to the patient, the sensing electrode being separate from the first electrode and the second electrode.

[0130] Example 34: the IMD of any of examples 21-33, wherein the stimulation signal is configured to induce a thoracic pump effect in the patient.

[0131] Example 35: the IMD of any of examples 21-34, wherein at least one of the first electrode or the second electrode is disposed within a middle cardiac vein (MCV) of the patient.

[0132] Example 36: the IMD of any of examples 21-35, wherein the stimulation signal is configured to provide Cardiac Contractility Modulation (CCM) therapy to the patient.

[0133] Example 37: the IMD of any of examples 21-36, wherein the stimulation signal is configured to cause the patient to reflexively inhale and contract the diaphragm.

[0134] Example 38: a method comprising: determining, by processing circuitry of an implantable medical device (IMD), a timing of the one or more events of a heart of a patient; determining, by the processing circuitry and based at least in part on the timing of the one or more events, a stimulation timing for a stimulation signal; and causing, by the processing circuitry, signal generation circuitry of the IMD to deliver, via an electrode coupled to the IMD, the stimulation signal to the diaphragm in accordance with the stimulation timing.

[0135] Example 39: the method of example 38, wherein the electrode comprises a first electrode, wherein the stimulation timing comprises a first stimulation timing, wherein the stimulation signal comprises a first stimulation signal, and wherein the method further comprises: determining, by the processing circuitry and based at least in part on the timing of the one or more events, a second stimulation timing for a second stimulation signal, the second stimulation signal being different from the first stimulation signal; and causing, by the processing circuitry, the signal generation circuitry to deliver, via a second electrode coupled to the IMD, the second stimulation signal to the heart.

[0136] Example 40: the method of example 39, wherein the first electrode and the second electrode are disposed on a same implantable lead extending from the IMD.Atorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1

[0137] Example 41 : the method of any of examples 38-40, wherein the second electrode is disposed along an outer surface of the diaphragm.

[0138] Example 42: the method of any of examples 38^11, wherein the second electrode penetrates the diaphragm.

[0139] Example 43: the method of any of examples 38^12, wherein the electrode is disposed at or around one or more muscle fibers of the diaphragm.

[0140] Example 44: the method of any of examples 38-43, wherein the one or more events of the heart comprises one or more of: a closure of one or more atrioventricular (AV) valves of the heart; an opening of the one or more AV valves; a closure of one or more semilunar valves of the heart; or an opening of the one or more semilunar valves.

[0141] Example 45: the method of any of examples 38-44, wherein determining the timing of the one or more events comprises determining, by the processing circuitry, the timing based on one or more of: sensed heart sounds of the heart; an electrocardiogram (ECG) signal of the heart; or an electrogram (EGM) signal of the heart.

[0142] Example 46: the method of any of examples 38^15, wherein determining the stimulation timing for the stimulation signal comprises: determining, by the processing circuitry and based on the timing of the one or more events, a subsequent closure time for one or more valves of the heart; and determining, by the processing circuitry, the stimulation timing for the stimulation signal prior to the subsequent closure time for the one or more valves of the heart.

[0143] Example 47: the method of example 46, wherein the one or more valves comprises mitral and tricuspid valves of the heart.

[0144] Example 48: the method of any of examples 46 or 47, wherein the stimulation timing corresponds to deliver of the stimulation signal at or prior to a ventricular contraction of the heart.

[0145] Example 49: the method of any of examples 38-48, wherein determining the stimulation timing for the stimulation signal comprises: determining, by the processing circuitry and based on the timing of the one or more events, a shirt time for a systole phase of a subsequent cardiac cycle of the heart; and determining, by the processing circuitry, the stimulation timing for delivery of the stimulation signal prior to the start time.

[0146] Example 50: the method of any of examples 38^49, wherein determining the timing of the one or more events comprises determining, by the processing circuitry, the timing based on one or more sensed signals from one or more sensors of the IMD, the one or more sensors comprising one or more of: an accelerometer; the electrode; or a sensing electrode coupled to the patient, the sensing electrode being separate from the electrode.Atorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1

[0147] Example 51 : the method of any of examples 38-50, wherein the stimulation signal is configured to induce a thoracic pump effect in the patient.

[0148] Example 52: the method of any of examples 38-51, wherein the electrode is disposed within a middle cardiac vein (MCV) of the patient.

[0149] Example 53: the method of any of examples 38-52, wherein the stimulation signal provides Cardiac Contractility Modulation (CCM) therapy to the patient.

[0150] Example 54: the method of any of examples 38-53, wherein the stimulation signal causes the patient to reflexively inhale and contract the diaphragm.

[0151] Example 55: an implantable medical device (IMD) comprising: a housing; an implantable lead extending distally from the housing, the implantable lead comprising: an elongated body extending from the housing; and an electrode disposed on a distal portion of the elongated body, the elongated body being configured to be disposed within a middle cardiac vein (MCV) of a patient; signal generation circuitry disposed within the housing and electrically coupled to the electrode; and processing circuitry disposed within the housing, the processing circuitry being configured to: determine a timing of one or more events of a heart of the patient; determine, based on the timing of the one or more events, a stimulation timing for each stimulation signal of one or more stimulation signals; and cause the signal generation circuitry to deliver, via the electrode, at least one stimulation signal of the one or more stimulation signals to one or more of a diaphragm or a heart of the patient based at least in part on the stimulation timings.

[0152] Example 56: the IMD of example 55, wherein the one or more events of the heart comprises one or more of: a closure of one or more atrioventricular (AV) valves of the heart; an opening of the one or more AV valves; a closure of one or more semilunar valves of the heart; or an opening of the one or more semilunar valves.

[0153] Example 57: the IMD of any of examples 55 or 56, wherein the processing circuitry is configured to determine the timing of the one or more events based on one or more of: sensed heart sounds of the heart; an electrocardiogram (ECG) signal of the heart; or an electrogram (EGM) signal of the heart.

[0154] Example 58: the IMD of any of examples 55-57, wherein to determine the stimulation timing for the stimulation signal, the processing circuitry is configured to: determine, based on the timing of the one or more events, a subsequent closure time for one or more valves of the heart; and determine the stimulation timing for delivery of the stimulation signal prior to the subsequent closure time for the one or more valves of the heart.

[0155] Example 59: the IMD of example 58, wherein the one or more valves comprises mitral and tricuspid valves of the heart.Atorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1

[0156] Example 60: the IMD of any of examples 58 or 59, wherein stimulation timing corresponds to delivery of the stimulation signal at or prior to a ventricular contraction of the heart.

[0157] Example 61 : the IMD of any of examples 55-60, wherein to determine, based on the timing of the one or more events, the stimulation timing for the stimulation signal, the processing circuitry is configured to: determine, based on the timing of the one or more events, a start time for a systole phase of a subsequent cardiac cycle of the heart; and determine the stimulation timing for delivery of the stimulation signal prior to the start time.

[0158] Example 62: the IMD of any of examples 55-61, wherein the electrode is configured to transition between a collapsed configuration and an expanded configuration.

[0159] Example 63: the IMD of any of examples 55-62, further comprising one or more sensors coupled to the processing circuitry, wherein the processing circuitry is configured to determine the timing of the one or more events of the heart based on one or more signals sensed from the patient via the one or more sensors, and wherein the one or more sensors comprises one or more of: an accelerometer; the electrode; or a sensing electrode coupled to the patient, the sensing electrode being separate from the electrode.

[0160] Example 64: the IMD of any of examples 55-63, wherein the at least one stimulation signal comprises a pacing signal configured to deliver cardiopulmonary resuscitation (CPR) to the patient.

[0161] Example 65: the IMD of any of examples 55-64, wherein the at least one stimulation signal is configured to induce a thoracic pump effect in the patient.

[0162] Example 66: the IMD of any of examples 55-65, wherein the at least one stimulation signal is configured to provide Cardiac Contractility Modulation (CCM) therapy to the patient.

[0163] Example 67: the IMD of any of examples 55-66, wherein the at least one stimulation signal is configured to cause the patient to reflexively inhale and contract the diaphragm.

[0164] Example 68: the system of any of examples 1-20, further comprising a housing configured to retain the signal generation circuitry and the processing circuitry, wherein the first electrode is disposed on a first lead connected to the housing, and wherein the second electrode is disposed on a second lead connected to the housing.

[0165] Example 69: The system of example 68, wherein the second lead is configured to be advanced through vasculature of the patient into a left inferior phrenic vein (LIPV) of the patient, and wherein the second electrode is configured to deliver the second stimulation signal from within the LIPV into the diaphragm.Atorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1

[0166] Example 70: the system of any of examples 68 and 69, wherein the first lead is configured to be affixed within a chamber of the heart of the patient to place the first electrode in contact with cardiac tissue of the chamber of the heart.

[0167] Example 71 : the system of any of examples 68 and 69, wherein the first lead is configured to be advanced through vasculature of the patient into a coronary sinus of the patient.

[0168] Example 72: the system of any of examples 68 and 69, wherein the first lead is configured to be advanced through vasculature of the patient into a left subclavian vein of the patient.

[0169] Example 73: An implantable medical device (IMD) comprising: a housing disposed within a patient; a first elongated body configured to be advanced within vasculature of the patient to a first location within the vasculature of the patient; a first electrode disposed on the first elongated body; a second elongated body configured to be advanced within the vasculature into a left inferior phrenic vein (LIPV) of the patient; a second electrode disposed on the second elongated body; signal generation circuitry disposed within the housing; and processing circuitry disposed within the housing, the processing circuitry being configured to: determine a timing of one or more events of a heart of the patient; determine, based on the timing of the one or more events, a first stimulation timing for a first stimulation signal; determine, based on the timing of the one or more events, a second stimulation timing for a second stimulation signal, the second stimulation signal being different from the first stimulation signal; cause the signal generation circuitry to deliver, based on the first simulation timing, the first stimulation signal to the heart via the first electrode; and cause the signal generation circuitry to deliver, based on the second stimulation timing, the second stimulation signal to a diaphragm of the patient via the second electrode.

[0170] Example 74: the IMD of example 73, wherein the first location is disposed in a blood vessel, the blood vessel comprising one of: a coronary sinus of the patient; or a left subclavian vein of the patient.

[0171] Example 75: the IMD of any of examples 73 and 74, wherein the first location is disposed within a right atrium (RA) of the heart.

[0172] Example 76: the IMD of any of examples 73-75, wherein the IMD comprises a leadless IMD.

[0173] Example 77: the IMD of any of examples 73-75, wherein the IMD comprises a leaded IMD, wherein the first elongated body comprises a first lead, and wherein the second elongated body comprises a second lead.

[0174] Example 78: the IMD of any of examples 73-75, further comprising the elements of any of examples 55-67.Atorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1

[0175] Various examples have been described. These and other examples are within the scope of the following claims.

Claims

Attorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1WHAT IS CLAIMED IS:

1. A system comprising: a first electrode; a second electrode, the second electrode being different from the first electrode; signal generation circuitry coupled to the first electrode and the second electrode; and processing circuitry configured to: determine a timing of one or more events of a heart of a patient; determine, based on the timing of the one or more events, a first stimulation timing for a first stimulation signal; determine, based on the timing of the one or more events, a second stimulation timing for a second stimulation signal, the second stimulation signal being different from the first stimulation signal; cause the signal generation circuitry to deliver, based on the first simulation timing, the first stimulation signal to the heart via the first electrode; and cause the signal generation circuitry to deliver, based on the second stimulation timing, the second stimulation signal to a diaphragm of the patient via the second electrode.

2. The system of claim 1, further comprising: an implantable medical device (IMD) comprising a housing configured to retain the processing circuitry and the signal generation circuitry; and an implantable lead configured to be connected to the housing of the IMD, wherein at least one of the first electrode or the second electrode is disposed on the implantable lead.

3. The system of claim 2, wherein the implantable lead is configured to extend distally away from the housing of the IMD, wherein the first electrode is disposed at a first position along the length of the implantable lead, and wherein the second electrode is disposed at a second position along the length of the implantable lead, the second position being proximal to the first position.

4. The system of any of claims 1-3, wherein the second electrode is configured to be disposed along an outer surface of the diaphragm.Attorney Docket No. A0011785 WOO 1 / 2222-544 WOO 15. The system of any of claims 1-3, wherein the second electrode is configured to penetrate the diaphragm.

6. The system of any of claims 1-5, wherein the one or more events of the heart comprises one or more of: a closure of one or more atrioventricular (AV) valves of the heart; an opening of the one or more AV valves; a closure of one or more semilunar valves of the heart; or an opening of the one or more semilunar valves.

7. The system of any of claims 1-6, wherein the processing circuitry is configured to determine the timing of the one or more events based on one or more of: sensed heart sounds of the heart; an electrocardiogram (ECG) signal of the heart; or an electrogram (EGM) signal of the heart.

8. The system of any of claims 1-7, wherein to determine the second stimulation timing for the second stimulation signal, the processing circuitry is configured to: determine, based on the timing of the one or more events, a subsequent closure time for one or more valves of the heart; and determine the second stimulation timing for delivery of the second stimulation signal prior to the subsequent closure time for the one or more valves of the heart.

9. The system of claim 8, wherein the second stimulation timing corresponds to delivery of the second stimulation signal at or prior to a ventricular contraction of the heart.

10. The system of any of claims 1-9, wherein to determine, based on the timing of the one or more events, the second stimulation timing for the second stimulation signal, the processing circuitry is configured to: determine, based on the timing of the one or more events, a start time for a systole phase of a subsequent cardiac cycle of the heart; and determine the second stimulation timing for delivery of the second stimulation signal prior to the start time.Atorney Docket No. A0011785 WOO 1 / 2222-544 WOO 111. The system of any of claims 1-10, further comprising one or more sensors coupled to the processing circuitry, wherein the processing circuitry is configured to determine the timing of the one or more events of the heart based on one or more signals sensed from the patient via the one or more sensors, and wherein the one or more sensors comprises one or more of: an accelerometer; the first electrode; the second electrode; or a sensing electrode coupled to the patient, the sensing electrode being separate from the first electrode and the second electrode.

12. The system of any of claims 1-11, wherein the second stimulation signal is configured to provide Cardiac Contractility Modulation (CCM) therapy or Diaphragm Synchronized Pacing (DSP) therapy to the patient.13: An implantable medical device (IMD) comprising: a housing disposed within a patient; a first elongated body configured to be advanced within vasculature of the patient to a first location within the vasculature of the patient; a first electrode disposed on the first elongated body; a second elongated body configured to be advanced within the vasculature into a left inferior phrenic vein (LIPV) of the patient; a second electrode disposed on the second elongated body; signal generation circuitry disposed within the housing; and processing circuitry disposed within the housing, the processing circuitry being configured to: determine a timing of one or more events of a heart of the patient; determine, based on the timing of the one or more events, a first stimulation timing for a first stimulation signal; determine, based on the timing of the one or more events, a second stimulation timing for a second stimulation signal, the second stimulation signal being different from the first stimulation signal; cause the signal generation circuitry to deliver, based on the first simulation timing, the first stimulation signal to the heart via the first electrode; andAtorney Docket No. A0011785 WOO 1 / 2222-544 WOO 1 cause the signal generation circuitry to deliver, based on the second stimulation timing, the second stimulation signal to a diaphragm of the patient via the second electrode.

14. The IMD of claim 13, wherein the first location is disposed in a blood vessel, the blood vessel comprising one of: a coronary sinus of the patient; or a left subclavian vein of the patient.

15. The IMD of any of claims 13 and 14, wherein the first location is disposed within a right atrium (RA) of the heart.

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