Energy harvester with rotational alignment

Abstract

A device having an energy harvester arrangement can include a housing configured for implantation in a human body, and an energy harvester disposed at least partially in the housing and configured to generate energy from movement of the housing. The energy harvester may include a member having a first end, a second end movable relative to the first end along a deflection axis, and a longitudinal axis extending between the first end and the second end, where the member is configured to passively rotate about the longitudinal axis as the housing moves, in this way, the deflection axis is self-aligned.

Description

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 496,488, filed April 17, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This technology relates generally to medical devices, and more specifically to devices and methods for enhancing energy harvesting. Background Technology

[0003] Various types of implantable medical devices have been developed for monitoring or treating one or more conditions in patients. For example, a pacemaker can monitor a patient's heart activity and deliver therapeutic electrical stimulation to the heart via electrodes. The electrical stimulation provided by a pacemaker can include signals such as pacing pulses to address abnormal heart rhythms (e.g., bradycardia). Some types of pacemakers are implanted at a distance from the heart and are connected to one or more leads that extend into the heart via blood vessels to position the electrodes in contact with the heart tissue. However, leads can be prone to breakage, which can lead to unreliable or incorrect pacing and may necessitate replacement of the leads or even the entire pacemaker.

[0004] Some types of pacemakers are sized to be implanted entirely within a chamber of the heart and may include electrodes integrated into or attached to the device housing instead of leads. Such pacemakers can be less invasive than conventional pacemakers and can avoid complications associated with lead breakage. However, the relatively small size of such pacemakers may limit the types of power sources that can be incorporated into the device. Attached Figure Description

[0005] Many aspects of this disclosure can be better understood by referring to the following accompanying drawings. The components in the drawings are not necessarily drawn to scale. Rather, the focus is on clearly illustrating the principles of this disclosure.

[0006] Figure 1 An example pacemaker implanted in a patient's heart according to an embodiment of the present technology is illustrated.

[0007] Figure 2 This is a perspective view of an example pacemaker configured according to an implementation scheme of this technology.

[0008] Figure 3 This is a side view of an example pacemaker configured according to an embodiment of this technology.

[0009] Figure 4 This is a schematic block diagram illustrating the electronic components of an example pacemaker configured according to an embodiment of the present technology.

[0010] Figure 5This is a cross-sectional side view of an example device including an energy harvesting mechanism according to an embodiment of the present technology.

[0011] Figure 6A This is a perspective view of an example energy harvesting mechanism with rotational alignment configured according to an embodiment of the present technology.

[0012] Figure 6B and Figure 6C These are illustrative schematic diagrams of example energy harvesting mechanisms in different rotational states.

[0013] Figures 7A to 7C These are exemplary schematic diagrams of various example bearing arrangements of energy harvesting mechanisms configured according to the implementation scheme of this technology.

[0014] Figure 8A This is an exemplary schematic diagram of an example energy harvesting mechanism with radial asymmetry configured according to an implementation scheme of this technology.

[0015] Figures 8B to 8D These are exemplary schematic diagrams of example energy harvesting mechanisms in different rotational states according to embodiments of the present technology.

[0016] Figures 9A to 9C This is an exemplary schematic diagram of an example energy harvesting mechanism with priority bias configured according to an implementation scheme of this technology.

[0017] Figure 10A This is an exemplary schematic diagram of an example energy harvesting mechanism configured according to an implementation scheme of this technology.

[0018] Figure 10B This is an exemplary schematic diagram of an example energy harvesting mechanism with one or more stops configured according to an implementation scheme of this technology.

[0019] Figure 11 This is an exemplary schematic diagram of an example energy harvesting mechanism with electrical leads configured according to an implementation scheme of this technology.

[0020] Figure 12A and Figure 12B The images show a side view and a cross-sectional view of an example energy harvesting mechanism with electrical leads configured according to an embodiment of the present technology.

[0021] Figure 13A and Figure 13B This is a graph illustrating the simulated probability distribution of power generated by an energy harvesting mechanism configured according to an embodiment of this technology. Detailed Implementation

[0022] This technology relates to energy harvester mechanisms, such as energy harvester mechanisms for implantable devices (e.g., implantable medical devices, such as heart pacemakers).

[0023] Embodiments of this disclosure will be described more fully below with reference to the accompanying drawings, in which the same numerals consistently denote the same elements across several figures, and exemplary embodiments are shown in the drawings. However, embodiments of the claims may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. The examples set forth herein are non-limiting examples and are merely examples of other possible examples.

[0024] As used herein, the terms “vertical,” “horizontal,” “upper,” and “lower” can refer to the relative orientation or position of a feature of an embodiment disclosed herein, taking into account the orientation shown in the figures. For example, “upper” or “topmost” can designate a feature positioned closer to the top of the page than another feature. However, these terms should be broadly interpreted to include embodiments with other orientations, such as inverted or tilted orientations, where top / bottom, above / below, above / below, up / down, and left / right can be interchanged depending on the orientation.

[0025] The headings provided herein are for convenience only and do not constitute an explanation of the scope or meaning of the invention protected by the claims. Embodiments under any heading may be used in conjunction with embodiments under any other heading.

[0026] I. Overview of Implantable Pacing Devices

[0027] Figures 1 to 4 A general overview of implantable devices configured according to embodiments of this technology is provided. Specifically, Figure 1 An example is shown of a pacemaker implanted in a patient's heart. Figure 2 An example configuration of a pacing device is shown. Figure 3 Another example configuration of the pacing device is illustrated, and Figure 4 Examples of electronic components that may be included in a pacemaker are shown. Figures 1 to 4 Any feature of the implementation scheme may be combined with each other and / or with any other implementation scheme described herein.

[0028] First refer to Figure 1 This illustrates a pacing device 100 implanted in a patient's heart H, configured to monitor the activity of the heart H and provide electrical stimulation (e.g., pacing signals) to the heart H. In some embodiments, the device 100 is a leadless intracardiac pacemaker configured to be fully implanted within a cardiac chamber, such as fully implanted in the right atrium (RA), fully implanted in the right ventricle (RV), fully implanted in the left atrium (LA), or fully implanted in the left ventricle (LV). The device 100 can be implanted at any of a variety of locations to sense and / or deliver therapy to any one or more chambers of the heart H. For example, as... Figure 1As shown, device 100 can be a right atrial intracardiac pacemaker implanted in a target implantation region T (e.g., Koch's triangle) within the RA of a patient's heart H. The target implantation region T may be located between the His bundle and the coronary sinus, and / or may be adjacent to the tricuspid valve. In other embodiments, device 100 may alternatively be configured as a right ventricular intracardiac pacemaker implanted in the RV of the heart H, wherein the target implantation region T is located at or near the apex of the RV along the endocardial wall.

[0029] Device 100 may include a housing 102 having size and shape factors suitable for transvenous delivery to the heart via a catheter. In an illustrated embodiment, housing 102 has an elongated shape extending from a distal portion 104 to a proximal portion 106. Housing 102 may have a generally cylindrical shape (e.g., sphere or capsule), a generally prismatic shape (e.g., rectangular prism), or any other suitable shape. Housing 102 may define an internal cavity housing electronic components of device 100 (e.g., circuitry, power supply, sensors).

[0030] Device 100 may include a fixation mechanism 108 for securing device 100 to tissue of the heart H. For example, fixation mechanism 108 may include one or more fixation elements configured to penetrate into the tissue, such as one or more forks, coils, barbs, etc. In an illustrated embodiment, fixation mechanism 108 is coupled to and extends outwardly from a distal portion 104 of housing 102. Thus, when device 100 is implanted, distal portion 104 may be positioned in contact with or adjacent to cardiac tissue, while proximal portion 106 may be spaced apart from cardiac tissue. However, in other embodiments, fixation mechanism 108 may be located at different portions of device 100.

[0031] Device 100 also includes a plurality of electrodes configured to sense the electrical activity of the heart H and / or deliver electrical therapy to the heart H. For example, device 100 may include two, three, four, five, six, seven, eight, nine, ten or more electrodes. Each electrode may be located at any suitable portion of device 100, such as on or coupled to housing 102 (e.g., distal portion 104, proximal portion 106, or an intermediate location between distal and proximal portions 106), or on or coupled to fixation mechanism 108. In some embodiments, device 100 includes one or more electrodes (e.g., cathodes) that directly contact cardiac tissue (e.g., cardiac tissue of a single or multiple cardiac chambers) to sense its activity and / or deliver electrical therapy to it. For example, such electrodes may be located at the distal portion 104 of housing 102 and / or incorporated into fixation mechanism 108. Device 100 may also include at least one electrode (e.g., an anode and / or return electrode) that does not directly contact cardiac tissue. Such electrodes may be located in a portion of the housing 102 that is spaced apart from the cardiac tissue, such as the proximal portion 106. Optionally, a single electrode may serve as a cathode for certain operations and as an anode and / or return electrode for other operations.

[0032] In some implementations, device 100 is connected via two-way wireless communication (such as Bluetooth). ® The external device 110 (illustratively shown) can be operatively connected to the external device 110 via Wi-Fi, Medical Implantable Communication Service (MICS), or other radio frequency communication technologies. The external device 110 may be a computing device or system located outside the patient's body and may be used in healthcare settings (e.g., in a clinic, hospital, or other medical facility), in the patient's home, or a suitable combination thereof. The external device 110 may be configured to control various operating parameters of the device 100, such as treatment parameters (e.g., pacing control parameters such as pacing intervals), sensing parameters, power management parameters, etc. For example, the external device 110 may transmit control signals to the device 100 to program one or more operating parameters of the device 100. Optionally, the external device 110 may display information associated with and / or received from the device 100, such as intracardiac electrogram (EGM) signals acquired by the device 100, motion sensor signals acquired by the device 100, operating parameters of the device 100, etc. In some implementations, external device 110 uses any suitable wired or wireless communication technology to transmit information received from device 100 to another computing device or system (e.g., computer, laptop computer, workstation, mobile device, server, remote patient management system) for display, processing, and / or storage. External device 110 may act as a “programmer” that allows physicians, patients, or other individuals to monitor and / or control the operation of device 100.

[0033] although Figure 1 A single device 100 is illustrated, but the technology is also applicable to implantable systems comprising multiple devices 100 implanted at different locations within the heart (H). For example, an implantable system may include a first device 100 in the RA and a second device 100 in the RV. In such embodiments, each device 100 may independently have any of the features described herein.

[0034] Figure 2 This is a perspective view of a pacing device 200 configured according to an embodiment of the present technology. The device 200 is configured to be implanted in a chamber of a patient's heart to monitor cardiac activity and / or provide electrical therapy to the heart (e.g., pacing therapy). The device 200 includes a housing 202 having a size and shape factor that allows the device 200 to be fully implanted into a single chamber of the patient's heart. In the illustrated embodiment, the housing 202 has an elongated shape (e.g., a generally cylindrical shape, a generally prismatic shape) extending between a distal end 204 and a proximal end 206. The housing 202 may define a hermetically sealed internal cavity for housing the electronic components of the device 200. The housing 202 may also include an attachment mechanism 208 (e.g., at the proximal end 206) configured to temporarily engage with a delivery tool during implantation and / or removal of the device 200.

[0035] The housing 202 may be formed partially or entirely of a conductive material, such as titanium or titanium alloys, stainless steel, MP35N (a non-magnetic nickel-cobalt-chromium-molybdenum alloy), platinum alloys, or other biocompatible metals or metal alloys, or other suitable conductive materials. Alternatively or in combination, the housing 202 may be formed partially or entirely of a non-conductive (e.g., insulating) material, such as ceramics, glass, sapphire, silicone, polyurethane, epoxy resin, acetyl copolymer plastics, polyetheretherketone (PEEK), liquid crystal polymers, other biocompatible polymers, or other suitable non-conductive materials.

[0036] Device 200 may include a plurality of electrodes 210a-210c configured to sense electrical activity of the heart and / or deliver electrical stimulation to the heart. In an illustrated embodiment, for example, device 200 includes a first electrode 210a and a second electrode 210b at or near a distal end 204 of housing 202, and a third electrode 210c on housing 202. The first electrode 210a and the second electrode 210b may be configured as cathodes in direct contact with cardiac tissue; for example, the distal end of the first electrode 210a may be configured to rest within the ventricular myocardium of a patient, and the second electrode 210b may be configured to contact the atrial endocardium of a patient. The third electrode 210c may be configured as an anode and / or a return electrode that does not directly contact cardiac tissue.

[0037] like Figure 2 As shown, the first electrode 210a may be an elongated structure extending from the distal end 204 of the housing 202 to penetrate the wall tissue of a first cardiac chamber (e.g., the chamber in which the device 200 is implanted) and enter the wall tissue of a different second cardiac chamber. For example, in some embodiments, the device 200 is implanted in the RA, wherein the distal end 204 is oriented toward the LV (e.g., similar to...). Figure 1 The device 100 is arranged in a manner that allows the first electrode 210a to extend through the wall tissue of the RA and into the wall tissue of the LV. In an illustrated embodiment, the first electrode 210a is configured as a coil (e.g., a helical coil and / or a coiled coil), while in other embodiments, the first electrode 210a may have different shape factors (e.g., an elongated dart, barb, fork, or other tissue-penetrating element). The first electrode 210a may include a proximal end attached to the distal end 204 of the housing 202, and a free distal end not attached to the housing 202. The distal end of the first electrode 210a may have a conical, hemispherical, or beveled distal tip with a narrow tip diameter (e.g., less than 1 mm) for penetrating into and through tissue layers. In some embodiments, the distal end of the first electrode 210a may have a sharp or angled tip and / or a sharp or beveled edge, but the sharpness may be constrained to avoid cutting actions that could cause lateral displacement of the distal end of the first electrode 210a and undesirable tissue trauma.

[0038] The second electrode 210b may be a structure extending from the distal end 204 of the housing 202 to contact the wall tissue of the first cardiac chamber without penetrating the wall tissue. The second electrode 210b may be located proximal to the first electrode 210a. The second electrode 210b may be configured as a coil (e.g., a partially spiral and / or coiled coil that does not form a complete turn), a loop, a button, a pad, or any other suitable form factor. The second electrode 210b may include a proximal end coupled to the distal end 204 of the housing 202, and may be coupled to or not coupled to the distal end of the housing 202. In some embodiments, the second electrode 210b is configured to flexibly maintain contact with the wall tissue (e.g., RA endocardium) of the cardiac chamber in which the device 200 is implanted, regardless of variations in the distance between the tissue surface and / or the distance between the distal end 204 of the housing 202 and the tissue surface, which may occur as the wall tissue moves during the cardiac cycle. Therefore, the second electrode 210b can be flexible and / or have spring-like properties. For example, the second electrode 210b can have a spring bias that pushes at least a portion of the second electrode 210b away from the distal end 204 of the housing 202 and toward the wall tissue of the heart chamber to maintain consistent contact.

[0039] The first electrode 210a and the second electrode 210b may be formed of conductive materials such as titanium, platinum, iridium, tantalum, or alloys thereof. The first electrode 210a may include one or more insulating coatings (e.g., parylene, polyurethane, silicone, epoxy resin) that reduce the conductive surface area of ​​the first electrode 210a to define a first electroactive region 212 (e.g., at or near the distal end of the first electrode 210a). The second electrode 210b may include one or more insulating coatings (e.g., parylene, polyurethane, silicone, epoxy resin) that reduce the conductive surface area of ​​the second electrode 210b to define a second electroactive region 214 (e.g., in an intermediate region between the proximal and distal ends of the second electrode 210b). This method can increase the impedance of the first electrode 210a and the second electrode 210b, and thereby reduce the current delivered during pacing pulses, which can save power used by the device 200. In some embodiments, the first electrode 210a and the second electrode 210b include a conductive material coating (e.g., TiN) on the first electroactive region 212 and the second electroactive region 214, respectively, to define the active regions. The first electrode 210a and the second electrode 210b may be made of the same material or may be made of different materials.

[0040] During pacing and / or sensing, all, substantially all, or a portion of the housing 202 may be used as a third electrode 210c (e.g., an anode and / or return electrode). In some embodiments, the third electrode 210c partially or completely surrounds a portion of the housing 202 at or near the proximal end 206. Although Figure 2 The third electrode 210c is illustrated as a single strip, but in other embodiments, the third electrode 210c may comprise a plurality of segments spaced apart along the longitudinal axis 216 of the housing 202 and / or around the periphery of the housing 202. Alternatively, the third electrode 210c may also be located at other locations along the housing 202, for example, at or near the distal end 204 or at other locations along the longitudinal axis 216.

[0041] In embodiments where the housing 202 is formed of a conductive material, one or more portions of the housing 202 may be electrically insulated by a non-conductive material (such as a coating of parylene, polyurethane, silicone, epoxy resin, or other biocompatible polymers or other suitable materials). For portions of the housing 202 not having a non-conductive material, one or more discrete regions of the housing 202 having a conductive material may be exposed to define a third electrode 210c. In embodiments where the housing 202 is formed of a non-conductive material, a conductive material may be applied to one or more discrete regions of the housing 202 to form the third electrode 210c. Optionally, the third electrode 210c may be a discrete component (e.g., a ring electrode) coupled to the housing 202.

[0042] Electrodes 210a-210c can be used to sense the electrical activity of one or more cardiac chambers and / or deliver electrical stimulation to one or more cardiac chambers. For example, the first electrode 210a can be paired with the second electrode 210b or the third electrode 210c to sense ventricular signals and deliver ventricular pacing pulses. As another example, the second electrode 210b can be paired with the first electrode 210a or the third electrode 210c to sense atrial signals and deliver pacing pulses to the atrial myocardium. In yet another example, the third electrode 210c can be paired with both the first electrode 210a and the second electrode 210b at different times for ventricular or atrial function, respectively. As yet another example, the first electrode 210a and the second electrode 210b can be paired with each other with different polarities for atrial and ventricular function.

[0043] In some embodiments, the second electrode 210b is configured as an atrial cathode electrode for delivering pacing pulses to atrial tissue at the target implantation site in conjunction with the third electrode 210c. The second electrode 210b and the third electrode 210c can also be used to sense atrial P waves for controlling (e.g., delivering in the absence of sensed P waves) atrial pacing pulses, and for controlling atrial-synchronized ventricular pacing pulses delivered using the first electrode 210a as the cathode and the third electrode 210c as the return anode. Figure 2 The illustrated configuration of electrodes 210a-210c allows device 200 to sense cardiac signals from one or more chambers of the heart and / or deliver cardiac pacing to one or more chambers of the heart. For example, this technology can facilitate the delivery of AV synchronous pacing using a single device 200 implanted within a single cardiac chamber (e.g., RA).

[0044] Device 200 may include a fixation mechanism 218 configured to secure device 200 to cardiac tissue at a target implantation region (e.g., Koch's triangle). In an illustrated embodiment, a first electrode 210a and / or a second electrode 210b at the distal end 204 of housing 202 may serve as fixation mechanism 218. In other embodiments, fixation mechanism 218 may be a component distinct from the first electrode 210a and / or the second electrode 210b, such as one or more separate barbs, forks, coils, darts, etc.

[0045] Figure 3 This is a side view of another pacing device 300 configured according to an embodiment of the present technology. Device 300 is configured to be implanted in a chamber of a patient's heart to monitor cardiac activity and / or provide electrical therapy to the heart. Figure 3 In the illustrated embodiment, the device 300 includes a housing 302, a plurality of fixed forks 304, a first electrode 306a, and a second electrode 306b.

[0046] The housing 302 may have size and shape factors that allow the device 300 to be fully implanted within a cavity in the patient's heart. For example, as Figure 3 As shown, housing 302 has an elongated shape factor that is generally cylindrical (e.g., spherical or capsule-shaped) extending between the distal end 308 and the proximal end 310. Housing 302 houses the electronic components of device 300 and can be hermetically or nearly hermetically sealed to prevent fluid from entering housing 302. The materials used to form housing 302 may include those described above relative to... Figure 2 The conductive material or the non-conductive material.

[0047] Device 300 may include a fixation mechanism configured to secure device 300 to cardiac tissue at a target implantation region (e.g., the endocardial wall near the apex of the RV). In an illustrated embodiment, device 300 includes a plurality of fixation forks 304 extending from a distal end 308 of housing 302 and configured to engage with cardiac tissue to secure housing 302 in a fixed position within the heart's ventricles. The fixation forks 304 may be configured to anchor housing 302 to cardiac tissue such that device 300 moves with cardiac tissue during cardiac contraction. Device 300 may include any suitable number of fixation forks 304, such as one, two, three, four, five, or more. The fixation forks 304 may be made of any suitable material, such as shape memory materials (e.g., nitinol). Alternatively or in combination, device 300 may be secured to cardiac tissue using other types of fixation mechanisms, such as, but not limited to, barbs, coils, darts, etc.

[0048] Optionally, the device 300 may include an attachment mechanism configured to temporarily attach the device 300 to a delivery tool, for example, for delivery and / or retrieval of the device 300. In an illustrated embodiment, for example, the proximal end 310 includes a flange 318 defining an opening. The flange 318 may be attached to a tether extending through an elongated shaft (e.g., a catheter) (e.g., by passing the tether through the opening) to implant or retrieve the device 300.

[0049] In some embodiments, device 300 is configured to sense electrical activity of the heart and / or deliver electrical stimulation to the heart via a first electrode 306a and a second electrode 306b (collectively, “electrode 306”). The first electrode 306a may serve as a cathode configured to electrically contact cardiac tissue and deliver pacing pulses thereto, and the second electrode 306b may serve as an anode and / or return electrode. Optionally, device 300 may be equipped with a plurality of cathode electrodes. Such a plurality of cathode electrodes may be configured to electrically contact cardiac tissue of a single cardiac chamber or of multiple cardiac chambers and deliver pacing pulses to the cardiac tissue of that single cardiac chamber or of the multiple cardiac chambers. In some such embodiments, the plurality of cathode electrodes are configured to electrically contact cardiac tissue of different cardiac chambers and deliver pacing pulses to the cardiac tissue of these different cardiac chambers. For example, one cathode electrode may be configured to electrically contact atrial tissue and deliver pacing pulses to that atrial tissue, and another cathode electrode may be configured to electrically contact ventricular tissue and deliver pacing pulses to that ventricular tissue.

[0050] Electrodes 306 can be configured in many different ways. For example, one or both electrodes of 306 may be discrete components mechanically coupled to housing 302. As another example, one or both electrodes of 306 may be defined by a conductive external portion of housing 302. Electrodes 306 may be electrically isolated from each other. In some embodiments, a portion of housing 302 is covered with or formed of an insulating material to isolate electrodes 306 from each other and / or to provide a desired size and shape for one or both electrodes of 306. Electrodes 306 may be electrically coupled to at least some internal electronic components (e.g., sensing circuitry, electrical stimulation circuitry, or both) of the internal electronics of device 300 within housing 302.

[0051] In the illustrated embodiment, the first electrode 306a is located at the distal end 308 of the housing 302. The first electrode 306a may be referred to as the end electrode, and the retaining fork 304 may be configured to anchor the device 300 to cardiac tissue such that the first electrode 306a remains in contact with the cardiac tissue. In some examples, the housing 302 includes an end cap 312 located at the distal end 308, and the end cap 312 includes a feedthrough assembly to electrically connect the first electrode 306a to electronics within the housing 302 while electrically isolating the first electrode 306a from the rest of the housing 302, such as including a second electrode 306b and / or other conductive portions of the housing 302.

[0052] The second electrode 306b can be located on the housing 302 away from the first electrode 306a (e.g., near the first electrode). Figure 3 As shown, housing 302 includes a first portion 314 and a second portion 316, wherein the first portion 314 is located proximal to end cap 312, and the second portion 316 is located proximal to the first portion 314. The second portion 316 may optionally define at least a portion of a power supply housing that houses the power source (e.g., a battery) for the pacemaker 300. In some embodiments, a second electrode 306b is located on the second portion 316, while in other embodiments, the second electrode 306b is located on the first portion 314.

[0053] In some embodiments, the second electrode 306b is a conductive portion of the housing 302 (e.g., an annular portion of the housing 302 that is partially or entirely made of a conductive material). Alternatively or additionally, the second electrode 306b may be a conductive material coated onto the material of the housing 302, or a discrete component coupled to the housing 302 (e.g., an annular electrode). The remainder of the housing 302 may contain or be coated with an insulating material such that the second electrode 306b is electrically isolated from the remainder of the housing 302 and / or from the first electrode 306a.

[0054] Figure 4 This is a schematic block diagram illustrating the electronic components of a pacemaker 400 configured according to an embodiment of the present technology. Figure 4 Any of the electronic components shown can be incorporated into any embodiment of the implantable device described herein, such as Figure 1 Device 100 Figure 2 Device 200 or Figure 3 Device 300.

[0055] like Figure 4As shown, device 400 includes a plurality of electrodes 402a-402c, which are electrically connected to components within housing 404 of device 400. Although device 400 is illustrated and described herein as having three electrodes 402a-402c (e.g., similar to...),... Figure 2 The device 400), however, in other embodiments, the device 400 may be modified to include a different number of electrodes, such as two electrodes (e.g., similar to device 200), but ... Figure 3 (The device 300) or any other suitable number of electrodes.

[0056] At least some of the electrodes in electrodes 402a-402c can be configured to contact tissue of one or more cardiac chambers, as described elsewhere herein. For example, as mentioned above... Figure 2 The first electrode 402a may be configured to electrically contact tissue of a first heart chamber (e.g., ventricular tissue) and deliver an electrical signal to that tissue, and the second electrode 402b may be configured to electrically contact tissue of a different second heart chamber (e.g., atrial tissue) and deliver an electrical signal to that tissue. The third electrode 402c may be an anode and / or return electrode that does not electrically contact heart tissue. Optionally, the first electrode 402a or the second electrode 402b may be omitted, or the device 400 may include additional electrodes that electrically contact tissue of a heart chamber (e.g., a first heart chamber, a second heart chamber, or another heart chamber) and deliver an electrical signal to that tissue.

[0057] Device 400 includes multiple electronic components within housing 404, such as switching circuit 406, sensing circuit 408, therapeutic generation circuit 410, one or more sensors 412, processing circuit 414, communication circuit 416, memory 418, and / or power supply 420. The various circuits may be programmable or fixed-function circuits, or may include programmable or fixed-function circuits configured to perform the operations described herein. Figure 4 One or more components of the illustrated device 400 may be part of an electronic assembly. For example, one or more of the following may be mounted on a circuit board of the electronic assembly of the device 400: switching circuit 406, sensing circuit 408, therapeutic generation circuit 410, sensor 412, processing circuit 414, communication circuit 416, and / or memory 418.

[0058] Switching circuit 406 may include one or more switches (e.g., a switch matrix, switch array, or other set of switches), multiplexers, transistors, and / or other circuitry. Switching circuit 406 may selectively connect one or more of electrodes 402a-402c to other components of device 400 (e.g., sensing circuit 408 and / or treatment generation circuit 410). The subset of electrodes 402a-402c to be used may depend on the specific operation of device 400 being performed, such as whether device 400 is sensing or delivering treatment, the location of the heart being monitored or treated, etc. In some embodiments, processing circuitry 414 determines which subset of electrodes 402a-402c should be used for a specific operation and controls switching circuit 406 to selectively connect those electrodes to appropriate components of device 400.

[0059] Sensing circuit 408 can monitor signals from at least one of the electrodes 402a-402c to monitor cardiac electrical activity, impedance, and / or other electrical phenomena. Sensing can be performed to determine heart rate and / or heart rate variability and / or detect ventricular synchrony, arrhythmias (e.g., tachyarrhythmias), and / or other electrical signals. Sensing circuit 408 may include filters, amplifiers, analog-to-digital converters, and / or other circuitry configured to sense cardiac electrical signals via one or more of the electrodes 402a-402c.

[0060] In some embodiments, a switching circuit 406, controlled by processing circuitry 414, selectively connects sensing circuitry 408 to selected combinations of electrodes 402a-402c, for example, to selectively sense electrical activity in one or more chambers of the heart. For example, switching circuitry 406 may connect each of the first electrode 402a and the second electrode 402b (in combination with the third electrode 402c) to a corresponding sensing channel provided by sensing circuitry 408 to sense electrical signals from cardiac tissue that are in electrical contact with the first electrode 402a (e.g., ventricular tissue) and the second electrode 402b (e.g., atrial tissue), respectively. In some embodiments, sensing circuitry 408 is configured to detect events (e.g., depolarization) within the cardiac electrical signal and provide indication of such events to processing circuitry 414. In this way, processing circuitry 414 can determine the timing of atrial and / or ventricular depolarization and can control the delivery of cardiac pacing (e.g., AV-synchronized cardiac pacing) based on this timing.

[0061] Therapeutic generation circuit 410 can generate electrical stimulation signals, such as cardiac pacing pulses. Therapeutic generation circuit 410 can be electrically connected to one or more electrodes 402a-402c to deliver pulses to a portion of the myocardium within the heart via one or more electrodes 402a-402c. In some embodiments, therapeutic generation circuit 410 delivers pacing stimulation in the form of electrical pulses. Therapeutic generation circuit 410 may include charging circuitry and one or more charge storage devices (e.g., capacitors). Optionally, therapeutic generation circuit 410 may include switches and / or other circuitry to control when the charge storage devices discharge to electrodes 402a-402c.

[0062] The switching circuit 406, controlled by the processing circuit 414, can direct the electrical stimulation signal from the treatment generation circuit 410 to a selected combination of electrodes 402a-402c with selected polarities, for example, to selectively deliver pacing pulses to the RA, RV, LV, and / or ventricular septum of the heart. For example, to pace one or both ventricles, the switching circuit 406 can electrically connect a first electrode 402a (e.g., the first electrode contacting the wall tissue of the ventricle or ventricular septum) to the treatment generation circuit 410 as a cathode, and connect one or both of the second electrode 402b or the third electrode 402c to the treatment generation circuit 410 as an anode. As another example, to pace the RA, the switching circuit 406 can connect a second electrode 402b (e.g., the second electrode contacting the RA endocardium) to the treatment generation circuit 410 as a cathode, and connect one or both of the first electrode 402a or the third electrode 402c to the treatment generation circuit 410 as an anode.

[0063] Processing circuitry 414 may include one or more processors, such as microprocessors, controllers, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or equivalent discrete or analog logic circuitry. In some embodiments, processing circuitry 414 may include multiple components (such as any combination of one or more microprocessors, controllers, DSPs, ASICs, and / or FPGAs) and other discrete or integrated logic circuitry. The functionality attributed herein to processing circuitry 414 may be embodied in software, firmware, hardware, or any combination thereof.

[0064] Processing circuit 414 can control treatment generation circuit 410 to deliver stimulation therapy to the patient's heart according to treatment parameters, which can be stored in memory 418. For example, processing circuit 414 can control treatment generation circuit 410 to deliver electrical pulses with amplitude, pulse width, rate, frequency, and / or electrode polarity specified by the treatment parameters. In this way, treatment generation circuit 410 can deliver pacing pulses to the heart via one or more electrodes 402a-402c. Device 400 can use any combination of electrodes 402a-402c to deliver therapy and / or detect electrical signals from the patient.

[0065] Memory 418 (e.g., a data storage device or other non-transitory medium) may store computer-readable instructions that, when executed by processing circuitry 414, cause device 400 to perform the various operations described herein. Memory 418 may include any volatile, non-volatile, magnetic, optical, or electrical medium, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, or any other digital or analog medium.

[0066] Sensor 412 may include one or more sensing elements that convert patient physiological activity into electrical signals to sense values ​​of corresponding patient parameters. Sensor 412 may include one or more motion sensors, optical sensors, chemical sensors, temperature sensors, pressure sensors, and / or any other type of sensor. Sensor 412 may output patient parameter values ​​to processing circuitry 414, which can be used as feedback to control the sensing and / or delivery of treatment by device 400.

[0067] For example, sensor 412 may include at least one motion sensor, such as one or more inertial measurement units (IMUs), accelerometers, gyroscopes, electric or magnetic field sensors, and / or other devices capable of detecting the motion and / or position of device 400. Motion of device 400 detected by the motion sensor may indicate cardiac events (e.g., ventricular pacing activation), blood flow through the heart, patient posture, patient activity, and / or noise. Processing circuitry 414 may control and / or monitor motion data generated by the motion sensor to identify one or more features of cardiac contraction within the signal (e.g., on a beat-by-beat basis or otherwise) to facilitate the delivery of treatment (e.g., delivery of ventricular pacing pulses in an atrial-synchronized manner). Optionally, processing circuitry 414 may use the motion data to detect the patient's current activity level, which may be used for rate-responsive pacing of the patient's heart.

[0068] Communication circuit 416 is configured to allow device 400 to communicate wirelessly with another device, such as a device external to the patient's body (e.g., Figure 1 The external device 110 and / or another device under the control of the processing circuit 414. For example, the processing circuit 414 may receive updates on operating parameters from the other device, and / or may provide acquired data (e.g., sensed cardiac activity and / or other patient parameters) to the other device via the communication circuit 416. The communication circuit 416 may use radio frequency (RF) communication technology (e.g., via an antenna) and / or any other suitable communication mode.

[0069] Power source 420 delivers operating power to various components of device 400. Power source 420 may include one or more batteries, each of which may be independently rechargeable or non-rechargeable. Recharging of power source 420 can be accomplished through near-side inductive interaction between an external charger and an inductive charging coil within device 400. Alternatively or in combination, recharging of power source 420 may be achieved using energy harvesting mechanism 422 of device 400. Additional details of the energy harvesting mechanism and associated methods are provided in Section II below.

[0070] Figure 4 The components of the illustrated device 400 can be modified in many different ways. For example, Figure 4 Any of the components shown can be combined with each other; for example, the switching circuit 406 can be incorporated into the sensing circuit 408 and / or the treatment generation circuit 410. Figure 4 Any component shown can be divided into smaller sub-components. Figure 4 Some components are optional and can be omitted (e.g., switching circuit 406 and / or sensor 412). Device 400 may also include... Figure 4 Additional components not shown. For example, device 400 may include power management circuitry coupled to power source 420 to allow processing circuitry 414 to monitor the state of power source 420 (e.g., charge level, charge rate, net power entering and / or leaving power source 420, remaining battery life).

[0071] Figure 4 The components of the illustrated device 400 represent functions that can be included in any device of this technology. Figure 4 The components shown may include any discrete and / or integrated electronic circuit components that implement analog and / or digital circuits capable of producing the functions attributed to the components herein. For example, components may include analog circuits such as amplifier circuits, filter circuits, and / or other signal conditioning circuits. Components may also include digital circuits such as combinational or sequential logic circuits, memory devices, etc. Figure 4The function of a component can be manifested as one or more processors, hardware, firmware, software, or any combination thereof. Figure 4 The descriptions of different features as separate blocks are intended to highlight different functional aspects and do not necessarily imply that such components must be implemented through separate hardware or software parts. Instead, the functionality associated with one or more components can be performed by separate hardware or software parts, or integrated within common or separate hardware or software parts. For example, although in Figure 4 While exemplified as separate functional components, some or all of the functions attributed to the switching circuit 406, sensing circuit 408, treatment generation circuit 410, sensor 412, and / or communication circuit 416 may alternatively or additionally be implemented by the processing circuit 414, and vice versa.

[0072] II. Energy Harvesting Technology

[0073] In some implementations, this technology provides an implantable device that includes an energy harvesting mechanism (also referred to as an "energy harvester" or "harvester"). The power capacity of the implantable device's power source may be limited due to size constraints (such as if the device is implanted in a small space within a patient's body (e.g., within a single heart chamber)) and / or to reduce the risk of the device interfering with normal physiological function and safety considerations. To extend the lifespan of such implantable devices, an energy harvesting mechanism can be used to generate energy in situ to recharge the power source.

[0074] Figure 5 This is a cross-sectional side view of a device 500 including an energy harvesting mechanism 502 according to an embodiment of the present technology. Device 500 may be an implantable device, such as a pacemaker configured to monitor a patient's cardiac activity and provide electrical stimulation to the heart. In such embodiments, device 500 may include the above-described combination. Figures 1 to 4 Any features of the described device (e.g., electrodes, fixation mechanisms, circuitry, and / or other electronic components). However, in other embodiments, device 500 may be a different type of implantable medical device.

[0075] Device 500 includes a housing 504 having an elongated shape extending between a distal end 508 and a proximal end 510. Housing 504 defines an internal cavity 506 that houses an energy harvesting mechanism 502 and other components of device 500, such as a power supply 512, a power regulation circuit 514, and electronic components 516. When device 500 is implanted in a patient, energy harvesting mechanism 502 generates energy from physiological motion. For example, in some embodiments, device 500 is configured to be implanted within a patient's heart chamber and generates energy from cardiac motion (e.g., motion of the heart wall to which device 500 is attached) and / or blood flow through the heart chamber. The energy generated by energy harvesting mechanism 502 can be used to charge power supply 512, which in turn powers the operation of device 500.

[0076] In some embodiments, the energy harvesting mechanism 502 includes a piezoelectric element 518 that converts mechanical energy into electrical energy via the piezoelectric effect. The piezoelectric element 518 may be or include a flexible, elongated member (e.g., beam, plate, shaft, rod, fiber) made partially or entirely of a piezoelectric material, such as piezoelectric ceramics (e.g., lead zirconate titanate (PZT)), single-crystal piezoelectric materials (e.g., lead magnesium niobate-lead titanate (PMN-PT)), piezoelectric polymers (e.g., polyvinylidene fluoride (PVDF)), or piezoelectric composites (e.g., piezoelectric ceramics embedded in a polymer matrix, such as macrofiber composites). The piezoelectric element 518 may be cantilevered, wherein a first end 522 of the piezoelectric element 518 is fixed relative to the housing 504, and a second end 524 of the piezoelectric element 518 opposite to the first end 522 is movable relative to the housing 504. In the illustrated embodiment, the first end 522 of the piezoelectric element 518 is located near the distal end 508 of the housing 504, the second end 524 of the piezoelectric element 518 is located near the proximal end 510 of the housing 504, and the longitudinal axis of the piezoelectric element 518 is aligned (e.g., parallel) with the longitudinal axis of the housing 504. However, in other embodiments, the piezoelectric element 518 may be oriented differently relative to the housing 504. Additionally, the energy harvesting mechanism 502 may optionally include a plurality of piezoelectric elements 518.

[0077] In some embodiments, the second end 524 of the piezoelectric element 518 is coupled to a collector mass 520 (also referred to as a "test mass" or "inertial mass"). Due to the inertia of the collector mass 520, when the device 500 is subjected to external forces from physiological motion, the collector mass 520 can cause displacement of the second end 524 of the piezoelectric element 518 relative to the housing 504 and the fixed first end 522 of the piezoelectric element 518, and thus cause elastic deformation of the piezoelectric element 518. For example, the piezoelectric element 518 can be deformed from a stationary, straight configuration ( Figure 5The piezoelectric element 518 deforms into a bending configuration (e.g., an upward bending configuration or a downward bending configuration). The mechanical strain generated in the piezoelectric element 518 can produce a current that can be used to charge the power supply 512.

[0078] The power source 512 may include one or more rechargeable batteries electrically connected to the energy harvesting mechanism 502 to store energy generated by the energy harvesting mechanism 502. In the illustrated embodiment, the power source 512 is configured as a tubular structure surrounding at least a portion of the energy harvesting mechanism 502 (e.g., the intermediate portion of the piezoelectric element 518 between its distal end 508 and proximal end 510). This configuration can help reduce the overall size of the device 500 while maintaining sufficient space within the internal cavity 506 to allow movement of the harvester mass 520 and the piezoelectric element 518. However, in other embodiments, the power source 512 may have a different shape and / or may be located in different portions within the housing 504.

[0079] In some embodiments, device 500 includes a power conditioning circuit 514 electrically connected to energy harvesting mechanism 502 and power supply 512 and inserted between the energy harvesting mechanism and the power supply. The power conditioning circuit 514 may be configured to perform operations such as rectification, filtering, and voltage regulation on the electrical signal generated by energy harvesting mechanism 502 before it is transmitted to power supply 512.

[0080] Power supply 512 is electrically connected to electronic component 516 to power its operation. Electronic component 516 may include electronic parts of device 500, such as those described above. Figure 4 Any components described (e.g., switching circuit 406, sensing circuit 408, therapy generation circuit 410, sensor 412, processing circuit 414, communication circuit 416, and / or memory 418). Optionally, electronic component 516 may include components performing power management functions (e.g., processing circuit 414 and / or other circuits) such as monitoring the state of power source 512 (e.g., the charging level of power source 512; whether the charging level is increasing, decreasing, or constant; the net current and / or power entering power source 512) and / or monitoring the power output of energy harvesting mechanism 502 (e.g., the amount of current and / or power generated by energy harvesting mechanism 502), power consumption of electronic component 516, etc.

[0081] In some implementations, the implantable device may include an energy harvesting mechanism that is self-adjusting to increase the amount of energy that the energy harvesting mechanism can harvest from the movement of the device. The relevant principles can be found in [reference needed]. Figure 5The energy harvesting mechanism 502 is illustrated. As described with reference to the energy harvesting mechanism 502, the piezoelectric element 518 may have a preferred axis of motion (also referred to as the “primary bending direction” or “preferred flexure direction”) along which the piezoelectric element 518 primarily deflects to achieve its bending configuration. For example, in some embodiments, the piezoelectric element 518 may include a member having a flat body with a transverse axis and a longitudinal axis defining a plane, wherein the preferred axis of motion is orthogonal to this plane. The energy harvesting mechanism 502 typically generates maximum energy when the acceleration of the device 500 is aligned with the preferred axis of motion of the piezoelectric element 518. When such alignment occurs, the piezoelectric element 518 can achieve maximum beam deflection in response to external forces applied to the device 500 (e.g., from physiological motion, such as cardiac motion when the device 500 is implanted in the heart). Generally, such maximum beam deflection enables the energy harvesting mechanism to operate with high efficiency (e.g., generating an increased amount of energy for a given amount or amplitude of cardiac motion). Therefore, in some embodiments of an implantable device implanted in the heart, the implantable device may include an energy harvesting mechanism that is capable of self-aligning the piezoelectric element to the direction of maximum acceleration, regardless of the implant's location in the heart.

[0082] However, in many cases, the piezoelectric element may be poorly oriented relative to the direction of cardiac motion for energy harvesting purposes. For example, radially positioning the energy harvesting mechanism within the pacemaker during implantation surgery can be challenging because such radial positioning depends at least in part on the understanding of the dominant direction of cardiac motion and / or on the precision of anchoring the pacemaker to the cardiac tissue wall (which may require, for example, rotating helical or coiled electrodes to pierce the tissue). Furthermore, once the pacemaker is implanted in the patient, the dominant direction of cardiac tissue motion may change acutely and / or chronically with patient posture, activity, and / or the patient's cardiac condition.

[0083] Therefore, in some embodiments, a pacemaker or other implantable device may include an energy harvesting mechanism that can rotate to orient the piezoelectric element under various conditions (e.g., different patient postures, different patient activities, different patient cardiac health, etc.) to achieve maximum, near-maximum, or increased beam deflection. For example, Figure 6AThis is an exemplary schematic diagram of an example energy harvesting arrangement 600 including an energy harvesting mechanism 620 configured to perform rotational self-alignment. In addition to those described herein, the energy harvesting mechanism 620 may be similar to energy harvesting mechanism 502. For example, energy harvesting mechanism 620 may include a member 624 having a first end 624a and a second end 624b movable relative to the first end 624a along a flexural axis (e.g., preferably a motion axis), and a longitudinal axis (A) extending between the first end 624a and the second end 624b. In some embodiments, the longitudinal axis (A) is aligned with the geometric center of the cross-section of member 624. Member 624 may also include a harvester mass block 628 (e.g., similar to harvester mass block 520) coupled to the second end 624b of the member. Figure 6B and Figure 6C As shown, component 624 may be at least partially disposed within housing 604 (e.g., similar to housing 504). In some embodiments, component 624 may comprise a piezoelectric material, similar to the reference material. Figure 5 The piezoelectric element 518 is described. Furthermore, in some embodiments, the energy harvesting arrangement may include a plurality of members 624, such as in a radial distribution similar to that shown and / or described in U.S. Patent Application No. 63 / 496,471, filed with Attorney General's File No. A0009983US01, the entire contents of which are incorporated herein by reference.

[0084] The energy harvesting mechanism 620 with rotational alignment can be configured to passively rotate about a longitudinal axis (e.g., free rotation, such as without active assistance from a power actuator or other active guidance for rotational adjustment). For example, in some cases, the housing 604 can move in a direction along the axis of motion (C). When the housing is implanted in cardiac tissue, the axis of motion (C) can, for example, be the primary direction of cardiac motion. In response to movement of the housing along the axis of motion (C) that is not aligned with the flexural axis (B)... Figure 6B ), component 624 can be configured to passively rotate about the longitudinal axis until the flexural axis (B) is substantially aligned (or more closely aligned) with the motion axis (C), such as Figure 6C As shown. For example, in response to an angular offset of the angle (α) between the flexural axis (B) and the motion axis (C), the member can be configured to passively move in the first direction (e.g., as shown). Figure 6BThe component is rotated approximately α degrees in the counterclockwise direction (as illustrated) until the flexural axis (B) and the motion axis (C) are substantially aligned (or more closely aligned). Additionally or alternatively, the component may be configured to passively rotate an auxiliary angle of α degrees (i.e., 360-α degrees) in a second direction opposite to the first direction until the flexural axis (B) and the motion axis (C) are substantially aligned. In this way, the component can be configured to self-align the flexural axis (B) with the motion axis (C) along which the housing moves.

[0085] Unbound by any particular theory, it is believed that the deflection or flexure of component 624 (and / or the movement of the harvester mass 628) can contribute to the alignment of the deflection axis (B) and the motion axis (C) because the energy harvesting arrangement 600 tends to maximize resonance within the energy harvesting mechanism. When the deflection axis (B) and the motion axis (C) are not well aligned, the energy harvesting mechanism exhibits low resonance. Conversely, when the deflection axis (B) and the motion axis (C) are substantially aligned, the energy harvesting mechanism exhibits high resonance. Therefore, the deformation of component 624 in response to the movement of the housing can facilitate passive self-alignment of the deflection axis (B) and the motion axis (C) by increasing the natural tendency of resonance.

[0086] In some cases, passive rotation of the energy harvesting mechanism can be advantageous compared to actively powered rotation, at least because a passively rotating energy harvesting mechanism eliminates the additional power extraction that the actuator would otherwise require (thus increasing the amount of power available for the power demands of a pacemaker or other device). Additionally, because no separate actuator is needed to actively assist rotation, a passively rotating energy harvesting mechanism can be easier to construct and has lower space requirements. However, in some embodiments, the energy harvesting mechanism may additionally or alternatively be rotatable with active assistance from an associated actuator.

[0087] In some embodiments, the energy harvesting arrangement 600 may also include a bearing 610 that facilitates passive rotation of the energy harvesting mechanism 620 (including member 624) relative to the housing 604 about a longitudinal axis (A). For example, as Figure 6B and Figure 6CAs shown, the bearing 610 may be at least partially arranged within the housing 604 of the device. The bearing 610 may include an inner bearing surface 612 fixed relative to a first end 624a of the member 624, and an outer bearing surface 614 fixed relative to the housing 604, wherein the inner bearing surface 612 is configured to move freely relative to the outer bearing surface 614. For example, the inner bearing surface 612 may be telescopically engaged with the outer bearing surface 614 in a manner that allows the inner bearing surface 612 to rotate relative to the outer bearing surface 614. The friction of the bearing 610 may be adjusted such that the member 624 is configured to self-align with the principal direction of motion of the housing 604, rather than with the direction of gravity.

[0088] The first end 624a of component 624 can be fixed relative to the inner bearing surface 612 in various suitable ways. In some embodiments, the first end 624a of the component may be coupled to a shaft 622 including the inner bearing surface 612. For example... Figure 6B and Figure 6C As shown, for example, shaft 622 may have an outer surface that serves as an inner bearing surface 612. At least a portion of the outer surface or circumference of shaft 622 may have a curved or arcuate shape (e.g., may be circular or elliptical, or may have arc segments), which is configured to rotate relative to outer bearing surface 614. In some embodiments, member 624 may be substantially coupled to the center of shaft 622 such that the axis of rotation of shaft 622 (and inner bearing surface 612) is aligned with the longitudinal axis (A) of member 624. However, in some embodiments, member 624 may be radially offset from the center of shaft 622. First end 624a may be coupled to shaft 622 by suitable mechanical interlocking (e.g., press fit, mating feature, etc.), epoxy resin, and / or one or more suitable fasteners. Alternatively, first end 624a may be integrally formed with shaft 622. For example, first end 624a of member 624 may have a cross-section that expands relative to the rest of member 624, which is circular or elliptical, and / or otherwise includes an arcuate portion.

[0089] The outer bearing surface 614 may be part of a separate component within the housing 604 (e.g., the lining of the housing 604), or integrally formed as an inner surface of the housing 604 or other suitable feature. Similar to the inner bearing surface 612, at least a portion of the outer bearing surface 614 may have a curved or arcuate shape (e.g., it may be circular or elliptical, or it may have arc segments).

[0090] In some embodiments, the inner bearing surface 612 and / or the outer bearing surface 614 may include a lubricating or low-friction material (e.g., Delirium). ® Teflon ®(etc.), which helps to promote relative sliding rotation between the inner bearing surface and the outer bearing surface. Additionally or alternatively, lubricant may be applied to the inner bearing surface and the outer bearing surface and / or between the inner bearing surface and the outer bearing surface to help promote relative sliding rotation between these surfaces.

[0091] Although in some embodiments the bearing 610 may be at least partially integrated into the member 624, shaft 622, and / or housing 604, it should be understood that in some embodiments the bearing 610 may be a discrete component formed separately from the member 624, shaft 622, and / or housing 604. For example, the bearing 610 may be a ball bearing, wherein the inner ring engages with the member 624 and / or shaft 622, and the outer ring engages with the housing 604 (or other components coupled to the housing 604).

[0092] Figures 7A to 7C Different example implementations of bearings for energy harvesting arrangements are illustrated in the figure. Figure 7A An example energy harvesting arrangement 700a is illustrated, including a member 724 (with a harvester mass block 728) coupled to a shaft 722. The shaft 722 can engage with an outer bearing feature 710 in a sliding fit, allowing the shaft 722 to rotate within the outer bearing feature 710. The outer bearing feature 710 can, for example, be at least partially coupled to a housing (not shown) or a component coupled to the housing. Similar to what has been described above with respect to bearing 610, the shaft 722 may have a cylindrical surface (or other curved or arcuate surface) that serves as an inner bearing surface engaging with the outer bearing feature 710.

[0093] Figure 7B An example energy harvesting arrangement 700b, similar to energy harvesting arrangement 700a, is illustrated, except that energy harvesting arrangement 700b includes a shaft having a narrowed neck region 722b between axially spaced front flange 722a and rear flange 722c. The neck region 722b can engage with outer bearing feature 710 in a sliding fit, while the front flange 722a and rear flange 722c restrict axial movement of the shaft (and member 724) relative to outer bearing feature 710. Figure 7B As shown, the rear flange 722c can be a separate backing component (e.g., via threads, epoxy resin, etc.) attached to the neck region 722b. In some embodiments, the front flange 722a can additionally or alternatively be a separate component attached to the neck region 722b in a similar manner. However, in some embodiments, one or both of the front flange 722a and the rear flange 722c can be integrally formed with the neck region 722b. Furthermore, similar to the above description, at least a portion of the shaft can be integrally formed with the member 724. Although the front flange 722a and the rear flange 722c are... Figure 7BThe shaft is shown as having a generally square face, but it should be understood that other general shapes may be suitable in some embodiments of the shaft. For example, the shaft may be coupled to or include one or more outwardly flared (e.g., tapered) or spherical features that restrict axial movement of the shaft relative to the outer bearing feature 710.

[0094] Figure 7C An example energy harvesting arrangement 700c similar to energy harvesting arrangement 700b is illustrated, except that energy harvesting arrangement 700c has a shaft (e.g., front flange portion 722d and rear flange portion 722f) which is dimensionally closer to or equal to the diameter of the outer bearing feature 710 compared to the corresponding feature of energy harvesting arrangement 700b, and the neck region 722e has a shorter axial length compared to the neck region of energy harvesting arrangement 700b.

[0095] In some embodiments, a self-aligned energy harvesting arrangement may include a preferential rotational bias configured to facilitate the initiation of rotation of a component about its longitudinal axis (e.g., to help overcome static friction). In some embodiments, the rotational bias may be applied at least in part by an asymmetry (e.g., bilaterally asymmetrical mass distribution) across the longitudinal or rotational axis of the component in the energy harvesting mechanism, where the asymmetry can utilize gravity to drive or facilitate the rotation of the component. The asymmetric characteristics of the energy harvesting mechanism may be due to asymmetry in the harvester mass block, the component, the shaft connecting the component to the bearing, or any combination thereof. For example, as Figure 8A As shown, in some embodiments, the energy harvesting arrangement 800 may have an energy harvesting mechanism (including component 824 and harvester mass block 828), wherein the center of mass C mass The component 824 is radially offset by a certain distance (r) from its longitudinal axis (A), where the longitudinal axis (A) is the geometric center of the cross-section of component 824. Generally speaking, the action on C... mass The gravity above can be used to apply a rotational torque to component 824 according to the following equation 1:

[0096]

[0097] Where τ is determined by the mass m of the energy harvesting mechanism (including component 824 and harvester mass block 828), the gravitational acceleration g, and C. mass The torque generated by the distance (r) between the energy harvesting mechanism and the longitudinal axis around which it is configured to rotate.

[0098] Figures 8B to 8D An example operation of a self-aligned energy harvesting arrangement 800 is illustrated, which includes an energy harvesting mechanism (including component 824 and harvester mass block 828) with a preferred rotational bias and a bearing 810 coupled to the energy harvesting mechanism. Figure 8B An example is illustrated where the flexural axis (B) of component 824 is misaligned with the axis of motion (C) of the applied motion or with acceleration (e.g., applied to a housing or device in which an energy harvesting mechanism is arranged). Specifically, the flexural axis (B) is approximately orthogonal to the axis of motion (C), where none of the vector components of the applied motion are aligned with the flexural axis (B) of component 824. In this orientation of component 824, component 824 experiences low (e.g., minimal) radial acceleration or oscillating motion along its preferred flexural direction, resulting in low (e.g., minimal) energy generation of the energy harvesting mechanism. If the energy harvesting mechanism has radially symmetrically distributed mass blocks (e.g., such that C...), mass (coinciding with longitudinal axis A), then when member 824 is in the position of the applied axis of motion (C) as follows: Figure 8B With the orientation shown, the energy harvesting mechanism may find it difficult to rotate passively around the longitudinal axis (A). However, the offset center of mass C... mass Providing a rotational bias or torque τ can help initiate the rotation of the energy harvesting mechanism about the longitudinal axis (A) (e.g.) Figure 8C (As shown). The torque τ and / or oscillating acceleration of component 824 can further contribute to the passive rotation of the energy harvesting mechanism until the flexural axis (B) is substantially aligned with the motion axis (C). Figure 8D ).

[0099] although Figures 8B to 8D The radial offset C is illustrated. mass The advantage of the initial position where the deflection axis (B) is essentially orthogonal to the motion axis (C) is due to the offset of the centroid C. mass The provided rotational bias can also advantageously assist the self-alignment of the energy harvesting mechanism by helping it overcome static friction from any particular initial rotational orientation (e.g., in bearing 810).

[0100] In some embodiments, the energy harvester mechanism can be asymmetrical across or around the longitudinal axis of the member, at least in part due to the asymmetrical mass distribution of the harvester mass block. For example, in some embodiments, a first longitudinal side of the harvester mass block may have a larger mass than a second longitudinal side of the member (e.g., the side opposite to the first longitudinal side). For example, the harvester mass block may have an asymmetrical geometry, wherein one longitudinal side of the member has a larger mass than the other longitudinal side of the member. Figure 9AAs shown, for example, energy harvesting arrangement 900a may include an energy harvesting mechanism having a member 924 and a harvester mass block 928a coupled to the member 924, wherein the harvester mass block 928a may have a geometrically asymmetrical shape (e.g., a generally circular cross-section, but with portions cut off along the chords of the cross-section). The energy harvesting mechanism may be coupled to a bearing 910 and configured to rotate passively, as described elsewhere herein. It should be understood that in some embodiments, in addition to Figure 9A Beyond the geometric cross-section shown, the collector mass block 928a may have any suitable geometric cross-section that is asymmetrical (e.g., bilaterally asymmetrical) with respect to the longitudinal axis (A), thereby achieving a bilaterally asymmetrical mass distribution in the collector mass block. For example, the collector mass block 928a may be cut away at multiple circumferential points on one side of the longitudinal axis (e.g., shaped to form a flat surface in place of a portion of the cylinder).

[0101] As another example, the collector mass block may additionally or alternatively include at least one negative space gap that reduces the mass of the collector mass block on one longitudinal side. For example, as Figure 9B As shown, the collector mass block 928b may include a gap 927 radially offset from the longitudinal axis (A) (e.g., at least a portion of the gap is radially offset from the longitudinal axis). The gap may include, for example, a cavity, a recess, a cut, or other suitable shape. In some embodiments, the collector mass block 928b may include multiple gaps to create asymmetry in the mass distribution of the collector mass block 928b.

[0102] As another example, the collector mass block may additionally or alternatively include at least one region having a higher density of material than other regions of the collector mass block. For example, as Figure 9C As shown, the collector mass block 928c may include a first region 925 having a first density and a second region 929 having a second density higher than the first density. The second region 929 may be radially offset from the longitudinal axis (A) (e.g., at least a portion of region 929 may be radially offset from the longitudinal axis). The higher-density region 929 may be, for example, spherical, elliptical, or have any suitable shape. In some embodiments, the collector mass block 928c may include multiple higher-density regions (e.g., two, three, four, five, or more) to create asymmetry in the mass distribution of the collector mass block.

[0103] In some embodiments, the energy harvester mechanism may be additionally or alternatively asymmetrical across the longitudinal axis of component 924 due to the asymmetrical mass distribution of component 924. Furthermore, in some embodiments, the energy harvester mechanism may be additionally or alternatively asymmetrical across the longitudinal axis of component 922 (which connects component 924 to bearing 910) due to the asymmetrical mass distribution of component 922. For example, component 924 and / or shaft 922 may be asymmetrical due to asymmetrical geometry, voids, and / or one or more regions of higher density material, similar to those described herein. Figures 9A to 9C This is described for the quality block of the data collector.

[0104] Furthermore, in some embodiments, the preferential rotational bias in the energy harvesting arrangement can be additionally or alternatively applied by one or more characteristics of the bearings coupled to the energy harvesting mechanism. For example, such as Figure 10A As shown, in some embodiments, the energy harvesting arrangement 1000 may include an energy harvesting mechanism having a member 1024 and a harvester mass 1028, wherein the member 1024 is coupled to a shaft 1022 engaging with a bearing surface 1014. As shown in FIG10, the shaft 1022 and / or the bearing surface 1014 may be slightly elliptical, such that, at least in some orientations, the shaft 1022 (and member 1024) tends to passively rotate about the longitudinal axis (A) of the member 1024 to reduce mechanical interference between the shaft 1022 and the bearing surface 1014. In at least some cases, this tendency can provide a preferred rotational bias for the energy harvesting mechanism. Similarly, in some embodiments, the shaft 1022 and / or the bearing surface 1014 may additionally or alternatively have arcuate regions with different frictions and / or different degrees of deformability, which in at least some cases can provide a preferred rotational bias for the energy harvesting mechanism.

[0105] In some embodiments, the rotation of the energy harvesting mechanism (e.g., the rotation of a component) can be limited to a specific range of rotational motion. This limited range of motion can be predetermined. When a component in the energy harvesting mechanism rotates, this limited range of motion can help reduce interference with or caused by electronic components in the energy harvesting mechanism (e.g., leads, wires, other connections, etc.). As another example, when a component in the energy harvesting mechanism rotates, this limited range of motion can additionally or alternatively help avoid tension on electrical connections (e.g., leads or wires). In some embodiments, the rotation of a component can be limited to a range of rotation less than about 360 degrees, or less than about 270 degrees, or less than about 180 degrees about the longitudinal axis of the component. In some embodiments, the N-degree range of rotational motion may include N / 2 degrees of movement in a first direction (e.g., clockwise) and N / 2 degrees of movement in a second direction (e.g., counterclockwise).

[0106] In some embodiments, the energy harvesting arrangement may include one or more stops configured to limit rotation of the components within a range of rotational motion. For example, such as Figure 10B As shown, the energy harvesting arrangement 1000b may include one or more stops 1030 disposed on the bearing surface 1014b. Each stop 1030 may be configured to abut against a notch or other abutment feature of the shaft 1022b once the shaft (and attachment member 1024b) rotates to a particular rotational orientation. This mechanical abutment serves to substantially prevent further rotation of the shaft 1022b and the member 1024b. Therefore, the angular placement of the stops 1030 and / or the angular placement of the abutment feature of the shaft 1022b may at least partially define a limited range of rotational movement of the member 1024b. It should be understood that the energy harvesting arrangement may include... Figure 10B The mechanical abutment interaction shown differs from other mechanical abutment interactions. For example, in some embodiments, shaft 1022b may additionally or alternatively include one or more stops configured to mechanically abut against a cut in bearing surface 1014b. As another example, in some embodiments, shaft 1022b may have a varying radius and engage with a bearing surface that does not correspond to or match the cross-section of the shaft, such that mechanical interference between the shaft surface and the bearing surface increases when the shaft is in a particular rotational orientation. For example, as... Figure 10A As shown, shaft 1022 may have an elliptical cross-section having a minor axis and a major axis, and shaft 1022 may engage with a circular bearing surface 1014. In this example, mechanical interference substantially prevents contact between a point on the shaft surface along the major axis and the bearing surface, thereby substantially limiting the rotation of shaft 1022 and attachment member 1024.

[0107] Additionally or alternatively, in some embodiments, the energy harvesting arrangement may include one or more stops incorporating frictional interference to limit the rotation of the component within its rotational range. For example, in some embodiments, the shaft and / or the bearing surfaces engaging the shaft may include different arcuate segments with varying amounts of friction, allowing the shaft to rotate more freely in areas of lower friction between the shaft and bearing surfaces, and less freely in areas of higher friction. This can be achieved, for example, by selecting a high-friction material (e.g., Delirium) for the shaft and / or bearing surfaces. ® Teflon ® Adding texture features (e.g., pawls, ribs, bumps, etc.) to the shaft and / or bearing surfaces can increase friction in specific areas.

[0108] Furthermore, in some embodiments, the energy harvesting arrangement may include one or more electrical connections coupled to the component for transmitting energy (e.g., current) generated by the energy harvesting mechanism to a power source. For example, such as Figure 11 As shown and similar to other energy harvesting arrangements described herein, energy harvesting arrangement 1100 may include an energy harvesting mechanism comprising a member 1124 and a harvester mass block 1128, wherein electrical contacts 1140a and 1140b (e.g., positive and negative electrical contacts) are coupled to member 1124. Member 1124 may be coupled to shaft 1122, which engages with outer bearing feature 1110 to facilitate passive rotation of member 1124. Shaft 1122 may include one or more channels configured to carry electrical leads extending from electrical contacts 1140a and 1140b to power source 1130. For example, shaft 1122 may include two channels 1124a and 1124b for carrying electrical leads from electrical contacts 1140a and 1140b, respectively. Channels 1124a and 1124b may be elongated and extend axially along shaft 1124a, and then merge to form channel 1124c, which is configured to carry a bundle of combined leads from electrical contacts 1140a and 1140b. Alternatively, in some embodiments, shaft 1122 may include an annular channel that can carry leads from multiple electrical contacts. In some embodiments, the electrical leads from the electrical contacts (e.g., electrical contacts 1140a and 1140b) may include strain relief elements (e.g., excess length) to help prevent tension on the leads when shaft 1122 rotates relative to outer bearing feature 1110. In some embodiments, shaft 1122 may additionally or alternatively be configured to have a limited range of rotational movement (e.g., having one or more stops, as described herein, such as regarding...). Figure 10A and Figure 10B (as described above), to help avoid stress on the electrical leads when the shaft 1122 rotates relative to the outer bearing feature 1110.

[0109] Additionally or alternatively, in some embodiments, the energy harvesting arrangement may include one or more brush contacts that help maintain electrical continuity between the component and a power source, regardless of the rotational orientation of the shaft. For example, as Figure 12A and Figure 12BAs shown and similar to other energy harvesting arrangements described herein, energy harvesting arrangement 1200 may include an energy harvesting mechanism comprising a member 1124 and a harvester mass 1228, wherein electrical leads 1240a and 1240b (e.g., positive and negative wires) are coupled to member 1224. Member 1224 may be coupled to shaft 1222, which engages with outer bearing feature 1210 to facilitate passive rotation of member 1224. Electrical leads 1240a and 1240b may extend to conductive rings 1242a and 1242b located on shaft 1222, respectively. Spring contacts 1244a and 1244b may make electrical contact with conductive rings 1242a and 1242b, respectively, and further transmit power signals to a power source (not shown). Spring contacts 1244a and 1244b can contact conductive rings 1242a and 1242b with low-friction surface contacts that can be adjusted to generate rotational resistance, which produces desired system damping for the rotational movement of shaft 1222. For example, the spring force of spring contacts 1244a and 1244b and / or the outer diameter of shaft 1222 can be selected or otherwise adjusted to generate the desired rotational resistance while maintaining electrical continuity in the path from member 1224 to electrical leads 1240a and 1240b, conductive rings 1242a and 1242b, and spring contacts 1244a and 1244b.

[0110] As described herein, various embodiments of a passively rotating self-aligned energy harvesting mechanism can generate more energy when the flexural motion of the energy harvesting mechanism is substantially aligned with the motion of the housing or device containing the energy harvesting mechanism (for the maximum radial acceleration or oscillating motion of the energy harvesting mechanism). Figure 13A and Figure 13B These are plots illustrating the simulated probability distribution of power generated by a passively rotating, self-aligned energy harvesting mechanism (such as those described herein) within the implant for different implant orientations. These plots are based on animal data of cardiac pacemakers implanted in atrial sites other than the Koch triangle. Figure 13A ) and animal data on pacemakers implanted at the Koch triangle implantation site ( Figure 13B ).like Figure 13A and Figure 13B As shown, when the implant is oriented along the direction of the maximum radial acceleration of the energy harvesting mechanism (AR radial maximum value, VfA radial maximum value), such as aligned with the deflection direction of the energy harvesting mechanism, the implant is generally more likely to generate a greater amount of power (e.g., along the line). Figure 13A and Figure 13BThe X-axis is offset further to the right. When the implant is oriented along the direction of the minimum radial acceleration of the energy harvesting mechanism (AR radial minimum, VfA radial minimum), such as orthogonal to the deflection direction of the energy harvesting mechanism, generally speaking, the implant will be less likely to generate a greater amount of power (e.g., along the line). Figure 13A and Figure 13B The X-axis is shifted further to the left. Figure 13A and Figure 13B It also indicates the probability distribution function (AR radial mean, VfA radial mean) of the implant location between the orientations of maximum and minimum radial acceleration.

[0111] Example

[0112] The following embodiments are included to further describe some aspects of the present invention and should not be used to limit the scope of the invention.

[0113] Example 1. An apparatus comprising:

[0114] A housing, configured for implantation in a human body; and

[0115] An energy harvester, at least partially disposed within the housing and configured to generate energy from the movement of the housing,

[0116] The energy harvester includes a component having a first end, a second end movable relative to the first end along a flexural axis, and a longitudinal axis extending between the first end and the second end.

[0117] In response to the movement of the housing along a motion axis different from the flexural axis, the member is configured to passively rotate about the longitudinal axis until the flexural axis is more closely aligned with the motion axis.

[0118] Example 2. The apparatus according to Example 1, wherein, in response to movement of the housing along a motion axis different from the flexural axis, the member is configured to passively rotate about the longitudinal axis until the flexural axis is substantially aligned with the motion axis.

[0119] Example 3. The apparatus according to Example 1 or 2, wherein the component comprises a piezoelectric material.

[0120] Example 4. The apparatus according to any one of Examples 1 to 3, the apparatus further comprising a bearing arranged at least partially in the housing.

[0121] Example 5. The apparatus according to Example 4, wherein the bearing includes a first bearing surface fixed relative to the first end of the member and a second bearing surface fixed relative to the housing, and wherein the first bearing surface is configured to move freely relative to the second bearing surface.

[0122] Example 6. The apparatus according to any one of Examples 1 to 5, wherein the energy harvester is asymmetrical about the longitudinal axis.

[0123] Example 7. The apparatus according to any one of Examples 1 to 6, wherein the energy harvester has a centroid radially offset from the longitudinal axis.

[0124] Example 8. The apparatus according to any one of Examples 1 to 7, wherein the energy harvester includes a harvester mass block coupled to the second end of the member.

[0125] Example 9. The apparatus according to Example 8, wherein the collector mass block has a centroid that is radially offset from the longitudinal axis.

[0126] Example 10. The apparatus according to Example 8 or 9, wherein the collector mass block includes a gap radially offset from the longitudinal axis.

[0127] Example 11. The apparatus according to any one of Examples 8 to 10, wherein the collector mass block includes a first region having a first density and a second region having a second density higher than the first density, wherein the second region is radially offset from the longitudinal axis.

[0128] Example 12. The apparatus according to any one of Examples 1 to 11, wherein the rotation of the member about the longitudinal axis is limited to a rotation range of less than 360 degrees.

[0129] Example 13. The apparatus according to Example 12, wherein the rotation range is about 180 degrees or less.

[0130] Example 14. The apparatus according to Example 12 or 13, the apparatus further includes a stop configured to limit the rotation of the member within the rotation range.

[0131] Example 15. The apparatus according to any one of Examples 1 to 14, the apparatus further comprising a power source configured to be charged by the energy harvester.

[0132] Example 16. The device according to any one of Examples 1 to 15, the device further comprising one or more electrodes configured to perform at least one of the group consisting of electrical stimulation and sensing.

[0133] Example 17. The device according to any one of Examples 1 to 16, wherein the device is a pacemaker.

[0134] Example 18. The device according to Example 17, wherein the device is a leadless pacemaker.

[0135] Example 19. The apparatus according to any one of Examples 1 to 18, wherein the apparatus further includes circuitry configured to generate cardiac pacing pulses.

[0136] Example 20. An apparatus comprising:

[0137] A housing configured for implantation in a human body;

[0138] An energy harvester, at least partially disposed within the housing and configured to generate energy from the movement of the housing,

[0139] The energy harvester includes a component having a first end, a second end movable relative to the first end along a flexural axis, and a longitudinal axis extending between the first end and the second end.

[0140] The component is configured to passively rotate about the longitudinal axis as the housing moves, so that the flexural axis self-aligns.

[0141] Example 21. The apparatus according to Example 20, wherein the component comprises a piezoelectric material.

[0142] Example 22. The apparatus according to Example 20 or 21, the apparatus further comprising a bearing arranged at least partially in the housing.

[0143] Example 23. The apparatus according to Example 22, wherein the bearing includes a first bearing surface fixed relative to the first end of the member and a second bearing surface fixed relative to the housing, and wherein the first bearing surface is configured to move freely relative to the second bearing surface.

[0144] Example 24. The apparatus according to any one of Examples 20 to 23, wherein the energy harvester is asymmetrical about the longitudinal axis.

[0145] Example 25. The apparatus according to any one of Examples 20 to 24, wherein the energy harvester has a centroid radially offset from the longitudinal axis.

[0146] Example 26. The apparatus according to any one of Examples 20 to 25, wherein the energy harvester includes a harvester mass block coupled to the second end of the member.

[0147] Example 27. The apparatus according to Example 26, wherein the collector mass block has a centroid that is radially offset from the longitudinal axis.

[0148] Example 28. The apparatus according to Example 26 or 27, wherein the collector mass block includes a gap radially offset from the longitudinal axis.

[0149] Example 29. The apparatus according to any one of Examples 26 to 28, wherein the collector mass block includes a first region having a first density and a second region having a second density higher than the first density, wherein the second region is radially offset from the longitudinal axis.

[0150] Example 30. The apparatus according to any one of Examples 20 to 29, wherein the rotation of the member about the longitudinal axis is limited to a rotation range of less than 360 degrees.

[0151] Example 31. The apparatus according to Example 30, wherein the rotation range is about 180 degrees or less.

[0152] Example 32. The apparatus according to Example 30 or 31, the apparatus further includes a stop configured to limit the rotation of the member within the rotation range.

[0153] Example 33. The apparatus according to any one of Examples 20 to 32, the apparatus further comprising a power source configured to be charged by the energy harvester.

[0154] Example 34. The device according to any one of Examples 20 to 33, the device further comprising one or more electrodes configured to perform at least one of the group consisting of electrical stimulation and sensing.

[0155] Example 35. The device according to any one of Examples 20 to 34, wherein the device is a pacemaker.

[0156] Example 36. The device according to Example 35, wherein the device is a leadless pacemaker.

[0157] Example 37. The apparatus according to any one of Examples 20 to 36, wherein the apparatus further includes circuitry configured to generate cardiac pacing pulses.

[0158] Example 38. An implantable medical device, the implantable medical device comprising:

[0159] An energy harvester includes a deflecting member having a first end, a second end movable relative to the first end, and a longitudinal axis extending between the first end and the second end, wherein the energy harvester is configured to generate energy from the deflection of the member; and

[0160] A bearing, connected to the energy harvester, is configured such that the component is passively rotated about the longitudinal axis.

[0161] The rotation of the component about the longitudinal axis is restricted to a range of rotational motion.

[0162] Example 39. The apparatus according to Example 38, wherein the component comprises a piezoelectric material.

[0163] Example 40. The apparatus according to Example 38 or 39, wherein the energy harvester is asymmetrical about the longitudinal axis.

[0164] Example 41. The apparatus according to any one of Examples 38 to 40, wherein the energy harvester has a centroid that is radially offset from the longitudinal axis.

[0165] Example 42. The apparatus according to any one of Examples 38 to 41, the apparatus further comprising a stop configured to restrict the rotation of the member about the longitudinal axis.

[0166] Example 43. The device according to Example 42, wherein the stop has a mechanical abutment.

[0167] Example 44. The apparatus according to Example 42 or 43, wherein the stop has frictional interference.

[0168] Example 45. The apparatus according to any one of Examples 38 to 44, the apparatus further comprising one or more electrodes configured to perform at least one of the group consisting of electrical stimulation and sensing.

[0169] Example 46. The device according to any one of Examples 38 to 45, wherein the device is a pacemaker.

[0170] Example 47. The device according to Example 46, wherein the device is a leadless pacemaker.

[0171] Example 48. The apparatus according to any one of Examples 38 to 47, wherein the apparatus further includes circuitry configured to generate cardiac pacing pulses.

[0172] in conclusion

[0173] While numerous embodiments of systems, devices, and methods for cardiac pacing have been described above, this technology is also applicable to other applications and / or other methods, such as other treatments involving implantable devices. Furthermore, other embodiments besides those described herein are also within the scope of this technology. Additionally, several other embodiments of this technology may have different constructions, components, or procedures than those described herein. Therefore, those skilled in the art should accordingly understand that this technology may have other embodiments with additional elements, or may have other embodiments without certain features shown and described above.

[0174] Implementations of this technology can be implemented, at least in part, in hardware, software, firmware, or any combination thereof. For example, various implementations can be implemented within one or more processors, including one or more microprocessors, DSPs, ASICs, FPGAs, or any other equivalent integrated or discrete logic circuits embodied in a programmer (e.g., a physician or patient programmer), stimulator, or other device, and any combination of such components. The terms "processor" or "processing circuitry" can generally refer to any of the aforementioned logic circuits, alone or in combination with other logic circuits, or any other equivalent circuitry.

[0175] The various processes described herein can be implemented, partially or entirely, using program code comprising instructions executable by one or more processors of a computing system to implement specific logical functions or steps within the process. The program code can be stored on any type of computer-readable medium, such as storage devices including disks or hard disk drives. Computer-readable media containing code or portions thereof can include any suitable medium known in the art, such as non-transitory computer-readable storage media. Computer-readable media can include volatile and non-volatile media, removable and non-removable media implemented using any method or technology for storing and / or transmitting information, including, but not limited to, random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies; optical disc read-only memory (CD-ROM), digital video disc (DVD) or other optical storage devices; magnetic tape cassettes, magnetic tape, disk storage devices or other magnetic storage devices; solid-state drives (SSDs) or other solid-state storage devices; or any other medium that can be used to store desired information and is accessible by system devices.

[0176] The description of embodiments of this technology is not intended to be exhaustive or to limit the technology to the exact forms disclosed above. Where the context permits, singular or plural terms may also include plural or singular terms respectively. While specific embodiments and examples of this technology have been described above for illustrative purposes, those skilled in the art will recognize that various equivalent modifications can be made within the scope of this technology. For example, although the steps are presented in a given order, alternative embodiments may perform the steps in a different order. The various embodiments described herein may also be combined to provide other embodiments.

[0177] As used herein, the terms “overall,” “substantially,” “about,” and similar terms are used as approximate terms rather than as terms of degree, and are intended to take into account the inherent biases of the measured or calculated values ​​that will be recognized by one of ordinary skill in the art.

[0178] Furthermore, unless the word “or” is explicitly limited to referring only to a single item excluding other items when referring to a list of two or more items, its use in such a list should be interpreted as including (a) any single item in the list, (b) all items in the list, or (c) any combination of items in the list. As used herein, the phrase “and / or” in the form of “A and / or B” refers to A alone, B alone, and A and B. Additionally, the term “including” is used throughout to indicate that at least one or more features are listed, without excluding any further number of the same features and / or other features of a different type.

[0179] In the event of any conflict between this disclosure and any material incorporated herein by reference, this disclosure shall prevail.

[0180] It should also be understood that specific embodiments have been described herein for illustrative purposes, but various modifications may be made without departing from the present technology. Furthermore, while advantages associated with certain embodiments of the present technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need to exhibit such advantages to fall within the scope of the present technology. Therefore, this disclosure and associated technology may cover other embodiments not explicitly shown or described herein.

Claims

1. An apparatus, the apparatus comprising: A housing configured for implantation in a human body; and An energy harvester, at least partially disposed within the housing and configured to generate energy from the movement of the housing, The energy harvester includes a component having a first end, a second end movable relative to the first end along a flexural axis, and a longitudinal axis extending between the first end and the second end. In response to the movement of the housing along a motion axis different from the flexural axis, the member is configured to passively rotate about the longitudinal axis until the flexural axis is more closely aligned with the motion axis.

2. The apparatus according to claim 1, wherein, In response to movement of the housing along a motion axis different from the flexural axis, the member is configured to passively rotate about the longitudinal axis until the flexural axis is substantially aligned with the motion axis.

3. The apparatus according to claim 1 or 2, wherein, The component includes a piezoelectric material.

4. The apparatus according to any one of claims 1 to 3, further comprising a bearing having a first bearing surface fixed relative to the first end of the member and a second bearing surface fixed relative to the housing, wherein, The first bearing surface is configured to move freely relative to the second bearing surface.

5. The apparatus according to any one of claims 1 to 4, wherein, The energy harvester is asymmetrical about the longitudinal axis.

6. The apparatus according to any one of claims 1 to 5, wherein, The energy harvester has a centroid that is radially offset from the longitudinal axis.

7. The apparatus according to any one of claims 1 to 6, wherein, The energy harvester includes a harvester mass block attached to the second end of the component.

8. The apparatus according to claim 7, wherein, The collector mass block has a centroid that is radially offset from the longitudinal axis.

9. The apparatus according to claim 7 or 8, wherein, The collector mass block includes a gap that is radially offset from the longitudinal axis.

10. The apparatus according to any one of claims 7 to 9, wherein, The collector mass block includes a first region with a first density and a second region with a second density higher than the first density, wherein the second region is radially offset from the longitudinal axis.

11. The apparatus according to any one of claims 1 to 10, wherein, The rotation of the component about the longitudinal axis is restricted to a range of less than 360 degrees.

12. The apparatus of claim 11, further comprising a stop configured to limit the rotation of the member within the range of rotation.

13. The apparatus according to any one of claims 1 to 12, further comprising a power source configured to be charged by the energy harvester.

14. The apparatus according to any one of claims 1 to 13, the apparatus further comprising one or more electrodes configured to perform at least one of the group consisting of electrical stimulation and sensing.

15. The apparatus according to any one of claims 1 to 14, wherein, The device is a pacemaker.

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