Implantable medical device with relative motion control

Abstract

An implantable medical device can include a plurality of electrical components connected to form an operational circuit, a container shaped to house the operational circuit, and a damping layer configured to reduce internal motion between the operational circuit and at least one of the plurality of additional components within the container, the damping layer selectively disposed on the operational circuit but not on the at least one additional component, the damping layer providing electrical insulation to the operational circuit, the damping layer including a moldable material in direct contact with an inner surface of the container. Methods of manufacturing such medical devices are also disclosed.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit and priority of U.S. Provisional Patent Application No. 63 / 065,277, filed August 13, 2020, the disclosure of which is incorporated herein by reference. Background Technology

[0003] Today, implantable medical devices are commonly used to monitor a patient's physiological or other parameters and / or deliver treatment. For example, various medical devices (e.g., neurostimulators, pacemakers, defibrillators, heart monitors, drug pumps, etc.) can be implanted to monitor and / or treat conditions related to the heart and / or nervous system. Some such devices can monitor the body and, in some cases, deliver electrical therapy (e.g., pacing, defibrillation, neuromodulation, etc.) or other treatments (drugs or insulin pumps) in some cases. Relative movement between electrical circuits and other components within the device can lead to interconnection problems and / or other malfunctions. In some cases, it may be desirable to reduce relative movement within the implantable medical device to increase its reliability. Summary of the Invention

[0004] This disclosure provides design, materials, and alternatives for use in medical devices, including delivery systems.

[0005] In one example, an implantable medical device includes an operating circuit for the implantable medical device comprising a first set of multiple electrical components, a metal container shaped to accommodate the operating circuit, and a damping layer selectively disposed on and attached to the first set of multiple electrical components, the damping layer providing electrical insulation to the first set of multiple electrical components and configured to reduce the sensitivity of the first set of multiple electrical components to vibration.

[0006] As an alternative to or supplement to the above example, the damping layer is in direct contact with the container.

[0007] As an alternative to or supplement to any of the above examples, the damping layer is molded onto the first group of multiple electrical components.

[0008] As an alternative to or supplement to any of the above examples, the damping layer includes thermoplastic, elastomer, or thermoplastic elastomer.

[0009] As an alternative to or supplement to any of the above examples, the damping layer does not contain epoxy resin.

[0010] As an alternative to or supplement to any of the above examples, the damping layer is a hot-melt polymer configured to be molded under low pressure.

[0011] As an alternative to or supplement to any of the above examples, the damping layer is impregnated with a desiccant.

[0012] As an alternative to or supplement to any of the above examples, the damping layer is impregnated with a hydrogen getter material.

[0013] As an alternative to or supplement to any of the above examples, the damping layer provides a reliable fixation of the operating circuit to the container by adhering it to the container.

[0014] As an alternative to or supplement to any of the above examples, the damping layer provides mechanical fixation of the operating circuit to the container.

[0015] As an alternative to or supplement to any of the above examples, the damping layer forms one or more cavities containing desiccant and / or hydrogen getter material.

[0016] As an alternative to or supplement to any of the above examples, the damping layer forms one or more cavities containing X-ray identification markers.

[0017] As an alternative to or supplement to any of the above examples, the operating circuit includes a printed circuit board assembly (PCBA), and the damping layer provides mechanical fixation of one or more of the battery, capacitor, energy transfer shield, speaker, telemetry component and charging coil to the PCBA.

[0018] As an alternative to or supplement to any of the above examples, the damping layer is impregnated with activated carbon or charcoal to absorb certain organic and / or inorganic compounds from the surface of the operating circuit.

[0019] As an alternative to or supplement to any of the above examples, the damping layer is impregnated with a composite desiccant, which is selected to achieve predetermined moisture absorption characteristics.

[0020] As an alternative to or supplement to any of the above examples, the damping layer is a composite material comprising two or more polymeric materials.

[0021] As an alternative to or supplement to any of the above examples, the operating circuit includes at least one second electrical component, and the damping layer is not disposed on the at least one second electrical component.

[0022] As an alternative to or supplement to any of the above examples, at least one second electrical component includes at least one of a battery, an accelerometer, a piezoelectric speaker, an analog timing crystal, and a Bluetooth module.

[0023] As an alternative to or supplement to any of the above examples, the damping layer includes a plurality of protrusions configured to provide an interference fit with the inner surface of the container.

[0024] As an alternative to or supplement to any of the above examples, the medical device has no metal layer between the damping layer and the container.

[0025] As an alternative to or supplement to any of the above examples, the medical device has no insulating layer between the damping layer and the container.

[0026] As an alternative to or supplement to any of the above examples, the operating circuit is configured to sense biological activity and / or deliver electrical therapy.

[0027] In another example, an implantable medical device includes a container, a plurality of electrical components connected to form an operating circuit, and a moldable material molded onto the operating circuit, the moldable material and the operating circuit forming a sub-module, the moldable material comprising a thermoplastic, elastomer, thermoplastic elastomer or hot melt polymer, wherein the sub-module is disposed within the container, the moldable material provides an adhesive or compression fit with the container, and the moldable material is configured to reduce internal movement of the operating circuit.

[0028] As an alternative to or supplement to any of the above examples, the container is metallic, and the moldable material is in direct contact with the inner surface of the container.

[0029] As an alternative to or supplement to any of the above examples, the implantable medical device further includes at least one additional electrical component within the container, with moldable material selectively disposed on the operating circuit but not on the at least one additional electrical component.

[0030] As an alternative to or supplement to any of the above examples, the moldable material is not epoxy resin.

[0031] As an alternative to or supplement to any of the above examples, the moldable material is a hot melt polymer configured to be molded under low pressure.

[0032] As an alternative to or supplement to any of the above examples, moldable materials provide a reliable fixation of the operating circuit to the container by adhering to it.

[0033] As an alternative to or supplement to any of the above examples, moldable materials provide mechanical fixation of the operating circuit to the container.

[0034] In another example, a method of manufacturing an implantable medical device includes molding a damping layer onto at least a portion of a printed circuit board assembly (PCBA) having a circuit board carrying a plurality of first electrical components to create covered operating circuitry, and the method includes placing the covered operating circuitry into a container of the medical device, wherein the damping layer is configured to reduce internal movement of the PCBA and / or components thereon.

[0035] As an alternative to or supplement to any of the above examples, the PCBA carries at least one second electrical component, and the damping layer does not cover the at least one second electrical component.

[0036] As an alternative to or supplement to any of the above examples, the step of molding the damping layer includes molding a hot melt polymer configured to be molded under low pressure.

[0037] As an alternative to or supplement to any of the above examples, the damping layer provides a reliable fixation of the operating circuit to the container by adhering it to the container.

[0038] As an alternative to or supplement to any of the above examples, the damping layer provides mechanical fixation of the operating circuit to the container.

[0039] As an alternative to or supplement to any of the above examples, the damping layer is impregnated with a desiccant.

[0040] As an alternative to or supplement to any of the above examples, the method further includes sealing the container airtight without adding a separate desiccant inside the container.

[0041] As an alternative to or supplement to any of the above examples, the damping layer is impregnated with a hydrogen getter material.

[0042] As an alternative to or supplement to any of the above examples, the method further includes sealing the container airtight without adding a separate getter inside the container.

[0043] As an alternative to or supplement to any of the above examples, the moldable material is not epoxy resin.

[0044] The above overview of some embodiments is not intended to describe every disclosed embodiment or every implementation of this disclosure. The following drawings and detailed description illustrate some embodiments in more detail. Attached Figure Description

[0045] In drawings that are not necessarily drawn to scale, similar reference numerals can describe similar parts in different views. Similar reference numerals with different letter suffixes can indicate different instances of similar parts. The drawings generally illustrate the various embodiments discussed in this document by way of example rather than limitation.

[0046] Figure 1 This is an exploded view of an exemplary implantable medical device (IMD);

[0047] Figure 2 yes Figure 1 The front perspective view of the IMD shown shows the external cover removed;

[0048] Figure 3 yes Figure 2 The rear perspective view of the IMD shown;

[0049] Figure 4 This is a front perspective view of the electronic component selected before adding the moldable material;

[0050] Figure 5 yes Figure 4 Rear perspective view of the electronic component shown;

[0051] Figure 6-9 These are front perspective views of different moldable material surface designs;

[0052] Figure 10 yes Figure 4 The electronic components shown are being added Figure 9 Front perspective view of the moldable material shown;

[0053] Figure 11 yes Figure 5 The electronic components shown are being added Figure 9 Rear perspective view of the moldable material shown;

[0054] Figure 12 It is along Figure 10 The side sectional view taken from line 12-12 in the middle;

[0055] Figure 13 yes Figure 10 The rear perspective view of the electronic components shown, in which the capacitors and piezoelectric components are positioned in place on the moldable material;

[0056] Figure 14 It is along Figure 13 The side sectional view taken from line 14-14 in the middle;

[0057] Figure 15A , 15B 16A and 16B are frequency-dependent amplitude and phase curves of two different devices at ambient temperature, showing the resonant peak of each device under burst chirp excitation.

[0058] Figure 17A , 17B 18A and 18B are frequency-dependent amplitude and phase curves of two different devices at 40°C, showing the resonant peaks of each device excited by a sudden chirp; and

[0059] Figure 19A and 19B This is a graph of the amplitude and phase of the transmission rate of a device at 40°C, which shows the resonant peak of each device excited by a sudden chirp. Detailed Implementation

[0060] For the terms defined below, unless a different definition is given elsewhere in the claims or this specification, these definitions shall apply. All numerical values ​​assumed herein are modified by the term "approximately," whether explicitly stated or not. In the context of numerical values, the term "approximately" generally refers to a range of numbers that a person skilled in the art would consider equivalent to the stated value (e.g., having the same function or result). In many cases, the term "approximately" may include numbers rounded to the nearest significant figure. Unless otherwise stated, other uses of the term "approximately" (e.g., in contexts other than numerical values) may be assumed to have their common and customary definitions(s), as understood from and consistent with the context of this specification.

[0061] The numerical range represented by the endpoints includes all numbers within that range, including the endpoints (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). While some suitable dimensions, ranges, and / or values ​​relating to various components, features, and / or specifications are disclosed, those skilled in the art will understand, inspired by this disclosure, that expected dimensions, ranges, and / or values ​​may deviate from those explicitly disclosed.

[0062] As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless otherwise expressly stated. As used in this specification and the appended claims, the term “or” is generally used to mean “and / or” unless otherwise expressly stated. It should be noted that, for ease of understanding, certain features of this disclosure may be described in the singular, even if such features may be plural or repeated in the disclosed embodiments(s). Each instance of these features may include and / or be contained by a single disclosure(s) unless expressly stated to the contrary. For simplicity and clarity, not all elements of this disclosure need to be shown in every figure or discussed in detail below. However, it should be understood that the following discussion can be equally applied to any and / or all components having more than one component, unless expressly stated to the contrary. Furthermore, for clarity, not all instances of some elements or features can be shown in every figure.

[0063] The term "monolithic" should generally refer to one or more elements made or constituted by a single structural or basic unit / element. Monolithic and / or holistic elements should exclude structures and / or features made by assembling or otherwise linking multiple discrete elements together.

[0064] Note that references to "embodiments," "some embodiments," "other embodiments," etc., in the specification indicate that the described embodiments may include specific features, structures, or characteristics, but each embodiment may not necessarily include those specific features, structures, or characteristics. Furthermore, such phrases do not necessarily refer to the same embodiment. Additionally, when a specific feature, structure, or characteristic is described in connection with an embodiment, unless expressly stated to the contrary, implementing that specific feature, structure, or characteristic in conjunction with other embodiments will be within the knowledge of those skilled in the art, whether explicitly described or not. That is, the various individual elements described below, even if not explicitly shown in a specific combination, are still considered to be combinable or arranged to form other additional embodiments or to supplement and / or enrich the described embodiments, as understood by those skilled in the art.

[0065] For clarity, certain designated numerical names (e.g., first, second, third, fourth, etc.) may be used throughout the description and / or claims to name and / or distinguish the various described and / or claimed features. It should be understood that the numerical names are not intended to be restrictive and are merely exemplary. In some embodiments, for brevity and clarity, the previously used numerical names may be modified and deviated from. That is, a feature designated as a “first” element may subsequently be referred to as a “second” element, a “third” element, etc., or may be omitted entirely, and / or different features may be referred to as a “first” element. The meaning and / or name in each case will be obvious to a person skilled in the art.

[0066] The following description should be read with reference to the accompanying drawings, which are not necessarily drawn to scale, and similar elements in different drawings are numbered the same. The detailed description and drawings are intended to illustrate the claimed invention and not to limit it. Those skilled in the art will recognize that the various elements described and / or shown can be arranged in various combinations and configurations without departing from the scope of this disclosure. The detailed description and drawings illustrate exemplary embodiments of the claimed invention. However, for clarity and ease of understanding, although each feature and / or element may not be shown in every drawing, it is understood that the feature(s) and / or element(s) are present in any way unless otherwise stated.

[0067] Many implantable medical devices (defibrillators, pacemakers, monitors, neurostimulators or modulators, drug pumps, etc.) include printed circuit board assemblies (PCBAs) and batteries. A PCBA typically includes a circuit board and multiple components placed on the board, with electrical connections between these components. More than one PCBA may be included; for example, an implantable defibrillator may include each of high-power and low-power PCBA configurations or "hybrids." Electrical components may include a wide variety of elements, including resistors, capacitors, transistors, discrete logic devices, logic arrays, various types of memory, amplifiers, chips carrying these components (or other components), oscillators, inductors, accelerometers in the form of microelectromechanical systems (MEMS), microcontrollers, etc., without intending to limit oneself to these named items. High-power systems, such as defibrillators, may include specially designed high-power capacitors, transformers, and energy-transfer resistors.

[0068] Pre-molded gaskets were previously the primary means of constraining PCBAs relative to other components within the housing or container. The container may be conductive, and in some cases, it may serve as an electrode for signal sensing or therapeutic delivery. The container is typically hermetically sealed. Hermetically sealed containers often also include one or more desiccant elements to remove residual or intruding moisture, and may include a hydrogen getter to capture hydrogen that may be released from device components after the hermetically sealed process.

[0069] Design requirements typically necessitate various verification tests, including but not limited to aging, thermal, and mechanical tests such as bending and drop tests. Component variations and tolerances between components within the container and on the PCBA can generate stresses that can adversely affect, for example, conductive interconnects between components and / or the components themselves (such as relatively sensitive optical insulators, when included). Furthermore, relatively large components (such as batteries and, particularly, high-power capacitors for defibrillators) have higher masses than other components and may exert greater stress on interconnects and the PCBA itself. New and alternative methods are needed to control movement and / or vibration within the device.

[0070] The innovations described below can be used in conjunction with many types of implantable medical devices (IMDs) and / or wearable medical devices. In some examples, the medical device may be, but is not limited to, an implantable cardiac monitor (ICM), an implantable cardioverter defibrillator (ICD), an implantable pacemaker, a leadless pacemaker (LCP), or other implantable electrophysiological devices configured for implantation in the body (including near or within the heart). Other implantable devices may include: neurostimulation devices, such as those for deep brain stimulation, spinal cord stimulation, vagus nerve stimulation, sacral nerve stimulation, and other brain, cardiac, or peripheral nerve stimulation; implantable pumps and / or sensors for, for example, but not limited to, diabetes management, drug delivery, etc.; and any other implantable medical device, particularly an active medical device having one or more of the following electronics for delivering therapy, sensing biological status, and / or communicating with other implantable or external devices.

[0071] Figure 1 This is an exploded view of an example IMD. The illustrated container includes a first container component 10 and a second container component 12. The first container component 10 and the second container component 12 can be made of any suitable biocompatible material. Titanium is an illustrative material, although other materials (such as medical-grade stainless steel) can be used in place of titanium or in combination with titanium. The external portions of the first container component 10 and the second container component 12 can be coated, shaped, or treated in any suitable manner. In some embodiments, the first container component 10 and the second container component 12 can be configured to fit together matingly, for example, with snap-fit ​​or overlap fit. Typically, the finished device will have a weld connecting the first container component 10 to the second container component 12, although additional intermediate components may also be included inside or outside the device, and for some embodiments, welding is not required using adhesives or snap-fit ​​fits.

[0072] The internal components shown in the exploded view include the operating circuitry of the device. In the illustrative embodiment shown, the operating circuitry is shown in a highly simplified manner and includes capacitors 20 and 22, a battery 30, and a PCBA 40. An electromagnetic interference (EMI) shielding 50 is also shown, which may include an energy-displacement resistor as disclosed in U.S. Patent 9,713,725, the disclosure of which is incorporated herein by reference. The operating circuitry shown is for an ICD (with relatively large capacitors 20 and 22), but it may also take various other forms as described above. The precise details of the components and / or operating circuitry can generally vary widely depending on the desired function of the device.

[0073] The operating loops contained within the IMD are highly sensitive, and relative movement between the PCBA and other components within the container can cause interconnection problems. In some cases, vibration or device bending can lead to trace cracking, solder joint cracking, and other failures. To prevent relative movement between PCBA 40 and other internal components, a damping layer can be molded onto PCBA 40. The damping layer can be a moldable material 60, such as, but not limited to, thermoplastics, elastomers, thermoplastic elastomers (TPEs), or hot-melt polymers. In some examples, the damping layer can be a composite or blend of two or more polymeric materials.

[0074] The moldable material 60 can provide reliable fixation of the operating circuit to the container by adhering to it. In some examples, the moldable material achieves this adhesive fixation during molding, where the container or a portion thereof is located in a mold fixture and, for example, at least partially defines a mold cavity. The moldable material can also, or alternatively, provide mechanical fixation to the container through friction, interlocking, or compression engagement with the container, for example, if the container or a portion thereof is added after molding. In some examples, the moldable material 60 can provide mechanical fixation to hold components such as one or more batteries, capacitors, dump shields, speakers, telemetry components, and recharge coils relative to the PCBA. The moldable material 60 also reduces relative movement of connectors within the IMD and provides electrical insulation for sensitive and / or high-voltage components.

[0075] In some examples, the PCBA 40 can be placed in a cavity that typically matches the internal geometry of the electronic component, and moldable material is molded onto the PCBA under low pressure. By "typically matched," the preceding sentence can be understood to mean that the cavity can be defined using a more or less flat surface spaced appropriately from the PCBA board (e.g., placed in a cavity fixture), allowing all components on the PCBA to be covered by the molding material. For example, if the maximum height of a component on the PCBA is, for example, but not limited to, 3 mm, the mold design can allow a 5 mm space between the PCBA board and the mold surface, thus providing at least 2 mm of moldable material at its thinnest point. This design can use, for example, but not limited to, a distance of 0.5 to 10 mm, or more or less spacing between the maximum component height and the cavity wall as needed. Thicker molding layers may require more time to cool / solidify, while thinner molding layers may present manufacturing difficulties if voids appear at the desired temperature and pressure. The mold does not have to be a flat piece offset from the PCBA. It can be of any geometry and does not have to cover every component.

[0076] In some examples, the moldable material 60 is not epoxy and / or does not require thermosetting. For example, the moldable material 60 may exclude or omit epoxy entirely. Other examples may include epoxy for selected uses within the IMD, but the material used as "molded material 60" to cover multiple components on the PCBA 40 does not contain epoxy.

[0077] An example of a material suitable for moldable material 60 is a thermoplastic elastomer, styrene-ethylene-butene-styrene (SEBS). Other examples include high-performance polyamide (PA) hot melt adhesives, such as... 653 and 673. They can be molded at low pressure (2 to 40 bar), are solvent-free, have short cycle times (10-50 seconds), do not require a thermosetting process, and adhere to polar plastics such as polyamide, acrylonitrile-butadiene-styrene (ABS), and polyvinyl chloride (PVC). 653 has a Shore A hardness of 77. 673 has a Shore A hardness of 90. In some examples, polyamide hot melt molding can achieve enhanced sealing and improved protection of electrical components compared to traditional two-part casting materials (epoxy resin) or potting resins or silicone resins. Polyamide hot melt molding materials are single-component materials that provide waterproof encapsulation and electrical insulation. Other hot melt materials, such as copolymers, can also be used. AS4226 or AS8998 (a type of polyolefin).

[0078] Further examples include Protective layer, including 726-SC and 728-G. These moldable acrylic polyurethanes have a rapid curing time (8-10 seconds) under UV or visible light and a Shore D hardness of 40-55. Another example of a suitable moldable material is Robnor. EL227CL is a two-part, low-viscosity polyurethane resin with a Shore A hardness of 16. Other acrylic polyurethanes can be used, such as... 9-7001 or 9-20479-B-REV-A. Another example of a moldable material is polycaprolactone.

[0079] In some examples, the moldable material 60 is molded only on the PCBA 40, thus omitting the moldable material 60 on other electrical components such as batteries and / or capacitors. In other examples, the moldable material 60 is molded on the PCBA 40 and at least one additional component of the operating circuit, said at least one additional component being, for example, but not limited to, a battery, a high-voltage capacitor, and interconnections between the battery, the high-voltage capacitor, and the PCBA. In some examples, the moldable material 60 covers both the high-voltage and low-voltage circuits. In some examples, the moldable material 60 covers only the high-voltage circuit. In other examples, the moldable material 60 covers only the low-voltage circuit.

[0080] Additional components of the operating circuit may include, but are not limited to, capacitors and batteries. Figure 2 In the example shown, the moldable material 60 is disposed on most of the PCBA 40 and completely encapsulates the battery, but most of the capacitors 20, 22 are not covered. Once the moldable material 60 is molded, a plurality of protrusions 62 are defined on the outer surface of the moldable material 60. Figure 2 In the example shown, the protrusion 62 is a series of concentric ridges extending from the moldable material 60 and into the outer surfaces of the capacitor 20 and battery 30. When the device is assembled, the protrusion 62 can provide an enhanced frictional fit with the inner surface of the container. In other examples, the moldable material 60 can encapsulate capacitors 20, 22. Once assembled, the moldable material 60 inhibits any internal movement within the device. Furthermore, the moldable material 60 provides electrical insulation for the components of the PCBA 40 and minimizes the risk of tolerance overlap issues. In some examples, the moldable material 60 can minimize or completely eliminate the need for padding and / or insulating components. In some examples, the presence of the moldable material 60 does not cause any visual or tactile changes for end users, including surgeons and patients, and the increase in mass is minimal.

[0081] In this example, the moldable material 60 is in direct contact with the inner surface of the container, and the IMD has no intermediate layer between the moldable material 60 and the container. Specifically, the device has no intermediate conductive metal layer between the moldable material 60 and the container, or alternatively, no insulating dielectric layer. In other examples, one or more additional layers or components may be provided, such as electromagnetic interference (EMI) shields disclosed in U.S. Patents 7,769,457 and / or 9,713,725, the disclosures of which are incorporated herein by reference. EMI shields can block or absorb external interference and prevent internal arcing events. If desired, the EMI shield can wrap around most of the internal device electronics and the moldable material. For example, as shown in patents 7,769,457 and 9,713,725, the EMI shield can have a first side and a second side joined at the edges, corresponding to the larger surface of the container. Energy-transferring resistors can also be provided to transfer stored energy to a high-power capacitor when needed (e.g., when a patient with a defibrillator experiences a non-sustained episode of a tachyarrhythmia, in which case the capacitor can be charged to a high voltage but cannot deliver treatment due to the spontaneous termination of the identified arrhythmia). Because energy-transferring resistors may require rapid dissipation of a relatively large amount of energy, larger-area resistors can be used, such as those printed on flexible circuitry and placed outside the moldable material and located between the moldable material and the container. As shown in U.S. Patent 9,713,725, energy-transferring resistors can be integrated into EMI shielding. Some examples (e.g., low-power treatment devices or monitoring devices) may omit the energy-transferring resistor and / or EMI shielding if desired. In the example shown, the EMI shielding and energy-transferring resistor are included at 50 (see...). Figure 3 ).

[0082] Figure 2 The area at 44 is highlighted and configured to couple feedthrough pins to the header. As is common in the art, a header is provided in association with a container for coupling leads to loops that are mechanically attached to the header / container and electrically attached to the interior of the IMD. For manufacturing purposes, the area of ​​the PCBA to be attached to the feedthrough may be prevented from receiving moldable material 60. In some examples, certain components of the IMD may be integrated into the header rather than appearing on the PCBA. For example, an MRI filter sub-circuit may be disposed in the header or directly attached to the header, or it may be integrated into the feedthrough structure associated with the header. If this is the case, the moldable material 60 may cover the internal components, but not the components associated with the header and feedthrough, if desired.

[0083] In one example, moldable material 60 can be applied to a portion of the assembly, where feedthrough wires extend out in areas of the base, and exposed wires or interconnects are also left for coupling to one or more additional components such as a battery or capacitor. For example, during the application of the moldable material, a portion of the electronic assembly may omit the battery / power supply to avoid stressing the battery cells and to ensure that the electronic assembly is not powered and therefore does not function during the molding step. In another example, as a final step before the container is hermetically sealed, after the electronic assembly is completed (where the battery and base are attached), moldable material can be added with the aid of a fixture that matches half of the container.

[0084] Furthermore, other components that may be present in the IMD may be covered by the moldable material 60 or may not be covered by it. For example, the motion-resistant properties of the moldable material 60 may raise concerns about reduced functionality of the accelerometer or piezoelectric speaker. If necessary, such components may be shielded from receiving the moldable layer 60 during the molding process, or may be omitted from the sub-assembly during the molding process, wherein the location for receiving the component is shielded from receiving the moldable layer 60, or wherein interconnects or wires not covered by the moldable layer 60 are provided after molding. In other examples, specific sub-circuits such as crystal oscillators and / or Bluetooth modules may be processed separately and provided without covering the moldable material.

[0085] Some IMD devices have a rechargeable battery (common for neuromodulation systems, for example) and may have an associated charging coil. Other devices may omit the battery and instead rely on received energy, such as magnetic, electrical, or mechanical energy (i.e., sound waves or ultrasound) received at the coil or transducer. If desired, the charging coil or other transducer may be positioned outside the moldable material 60, although in some examples the charging coil may be positioned such that the moldable material 60 covers it, or it may be positioned entirely outside the container, such as on the side of the container or within the base. For example, when the charging coil receives an incident electric or magnetic field from an external device, the charging coil may be able to warm up during its operation, and this may pose a risk of backflow of the moldable material 60.

[0086] Figure 3 It shows Figure 2The back of the IMD shown illustrates a moldable material 60 covering the battery, most of the PCBA 40, but not the capacitor 22. As shown, an EMI shield 50 and / or a transfer resistor are placed on the moldable material 60 and contact a portion 42 of the PCBA 40 that is not covered by the moldable material 60. In another example, the EMI shield 50 may also carry a piezoelectric speaker for audible alarms to the user or a vibration actuator for vibration alarms to the user. In some examples, items such as speakers, vibration actuators, and sensors (e.g., accelerometers) may be placed outside the moldable material 60 to prevent the vibration damping characteristics of the moldable material 60 from impairing the function of these components.

[0087] Figure 4 and Figure 5 Examples of the operating circuit of the IMD before the addition of moldable material are shown at the front and rear sides, respectively. PCBA40, battery 30, and two (high-voltage) capacitors 20, 22 are portions of the operating circuit at least partially covered with moldable material. The molding process can be performed outside the container, with the molded components inserted into the container during a later stage of manufacturing. In other examples, the operating circuit can be positioned within a first portion of the container, and moldable material can be placed in place on the circuit, followed by welding a second portion of the container to the first portion.

[0088] A method for manufacturing an IMD using a moldable material begins by selecting a component of an operating circuit that will be at least partially covered by the moldable material. A mold cavity is then defined relative to the PCBA and / or other components; this cavity can be a single part or can have multiple parts that function together. The mold itself may also be referred to as a fixture; the mold may include individually movable parts, for example, if a mandrel movable relative to the rest of the mold is provided, used by pressing it against the PCBA board (or other component) at a location where clearance is required. For example, a mandrel with a hollow end may be placed on a component that does not receive the moldable material 60.

[0089] Figure 6-9 Various examples of moldable materials 60, 160, 260, 360 with different designs for protrusions 62, 162, 262, 362 are shown. Figure 6 A moldable material 60 with a protrusion 62 is shown, which forms a concentric ring that will extend over a capacitor. Figure 7 A moldable material 160 with protrusions 162 forming domes is shown, some of which will be disposed on a capacitor. Figure 8 A moldable material 260 with protrusions 262 forming lines is shown, some of which will extend onto a capacitor. Figure 9A moldable material 360 is shown with protrusions 362 forming individual contours, one of which will be disposed on a capacitor. In addition... Figure 6-9 In addition to the protrusions 62, 162, 262, and 362 shown, protrusion 62 may also include recesses, ribs, wave patterns, or any other structure that provides an interference fit or friction fit with the interior of the container. Protrusion 62 controls stacking, component compressive forces, and / or system vibration response.

[0090] In some examples, moldable materials 60, 160, 260, and 360 will cover most of the PCBA 40, the battery will be fully encapsulated, and one of the capacitors 20 will only have a protrusion 62 deposited on the top surface, but otherwise remain uncovered by the moldable material 60, such as... Figure 10 As shown. In some examples of moldable materials 60, 160, 260, and 360, the second capacitor 22 will typically remain completely uncovered by the moldable material 60, such as... Figure 11 As shown in the rear view. At the rear of the assembly, the moldable material 60 can cover some portions of the PCBA 40, leaving others uncovered. (See image below.) Figure 12 As shown in the cross-section, the moldable material 60 can completely encapsulate most of the components on the battery 30 and PCBA 40, wherein the protrusion 62 extends above the horizontal plane of the moldable material 60.

[0091] In some examples, an intentional gap is left between the encapsulated battery and the container. This may allow the battery to expand, as batteries containing certain chemicals (such as LiMnO2 and others) often expand during use / aging due to internal chemical reactions causing changes in thickness. For this purpose, in some examples, a moldable material is applied in a mold separate from the container before being placed inside. In other examples, the battery may not be covered by the moldable material 60.

[0092] After the moldable material 60 has been molded onto the desired electrical component to form a submodule, the submodule can be assembled with additional components in the container to form an IMD. For example... Figure 13 and Figure 14 As shown, the EMI shield 50 can be added to the moldable material 60 on the back of the device, wherein a portion 52 of the EMI shield 50 contacts a portion 42 of the PCBA 40 that is not yet covered by the moldable material 60 (thus allowing electrical connection with it, since the EMI shield 50 can be electrically grounded).

[0093] Methods for manufacturing an IMD including moldable material 60 can be achieved by using the moldable material to fill large areas or selectively place it in key locations. The moldable material can be omitted on selected components (such as accelerometers, piezoelectric speakers, analog timing crystals, and Bluetooth modules). In one example, a component of the operating circuit to be covered is placed in a mold designed to hold the component and provide the external shape for the moldable material. Liquefied moldable material is then poured or injected into the mold and allowed to harden. In some examples, the PCBA may have one or more orifices to allow the moldable material to flow through, thereby creating internal features that receive desiccant and / or hydrogen getter material.

[0094] In one example, the moldable material can form one or more cavities (e.g., defined voids) for later placement of desiccant and / or hydrogen getter material. In another example, the moldable material can form cavities configured to receive X-ray identification markers. Post-processing (e.g., removal processes) can be performed to create cavities or voids for placement of desiccant, hydrogen getter, or X-ray identification markers. Desiccant, hydrogen getter material, and / or X-ray identification markers can be added during assembly. In another example, liquefied moldable material can be selectively deposited onto certain electrical components using a nozzle connected to a reservoir of liquefied moldable material. Protrusion 62 can be formed by molding or selective deposition. Components not covered by moldable material can be masked. Examples of masking materials include polysulfone pads, polymers with a melting temperature higher than that of the moldable material 60, and / or metallized shielding on polyetheretherketone (PEEK) pads.

[0095] Example

[0096] Several devices were fabricated, and in some examples, PCBA resonance was eliminated. In other examples, the primary resonant frequency of the electronic components was changed from approximately 500 Hz to approximately 2000 Hz. This change in resonance makes sensitive components less likely to resonate and be damaged during vibration exposures, such as during transport, MRI, or everyday use. Lower frequencies are more destructive and more likely to occur, so higher resonances help avoid damage and generally indicate a higher level of mechanical strength. Furthermore, the selective encapsulation of moldable material on the electronic components exhibited a linear vibrational response when subjected to random vibrations, which conventional devices may not show. A linear vibrational response typically indicates mechanical strength (i.e., no rattling or clicking sounds from components within the housing). A nonlinear vibrational response can manifest as vibrational failure of the components themselves or failure upon exposure to other load conditions, such as mechanical shocks or forces exerted by ribs, muscles, and skin during implantation.

[0097] The moldable material reduces the internal movement of the PCBA relative to other internal components. Laser scanning vibrometer testing can be used to analyze the vibration response of an IMD comprising moldable material 60 covering one or more internal components. This test examines the amplitude of the relative motion of the device filled with moldable material 60 at an associated resonant frequency.

[0098] Previous subcutaneous implantable cardioverter defibrillator (S-ICD) devices, built using existing standard frameworks and shielding techniques, showed a resonant frequency of approximately 500 Hz when tested with 0.3V burst chirps ranging from 100 to 3000 Hz. Transmission rate is a measure of relative motion, calculated by dividing the output acceleration by the device's input acceleration. The design goal was to reduce the magnitude of the transmission rate, meaning that internal components moved similarly to the edge of the pulse generator (PG) canister, and also to maximize the resonant frequency.

[0099] Two test S-ICD devices were created using functional internal components, but the top gasket was replaced with a moldable material. The cans were spot-welded to seal. These devices were then subjected to vibration testing, and... Figure 15A and 16A The graph shows the relationship between the amplitude [m / s² / (m / s²)] on the x-axis and the frequency [Hz] on the y-axis. Figure 15B and 16B The graphs showing the relationship between phase on the x-axis and frequency [Hz] on the y-axis are illustrated, with each graph tested using ambient temperature. Figure 17A As shown in -B and 18A-B, additional tests were performed on the same devices at 40°C to simulate the device implantation environment. No PCBA bending mode was observed on these devices; the resonance corresponds to the bending mode of the pulse generator canister. The tests did indeed show a spike in the transmittance at 1500Hz, which was determined to be caused by the fixture itself rather than the device under test. This is due to the presence of a moldable material. The vibration response of the device is linear, so random vibration tests (14 GRMS) were performed at 40°C. The resulting graphs are shown below. Figure 19A -B. Similarly, there is no PCBA bending mode, and the observed resonance corresponds to the bending mode of the pulse generator tank.

[0100] Add 60g of moldable material (e.g.) The filler material significantly increases the resonant frequency in sudden chirped excitation by eliminating the first bending mode of the PCBA, thereby improving the device's vibration performance. In these tests, the resonant frequency increased from 430 Hz in the previous build process to 2010 Hz using the moldable material 60. By adding the moldable material, the first PCBA bending mode was eliminated. The component also responded linearly and exhibited an increased resonance under random vibration excitation. Therefore, the tests conducted demonstrate the invention's ability to reduce vibration under test conditions, including eliminating the PCBA bending mode.

[0101] In some examples, the desiccant can be added to the moldable material in liquid form and mixed before the moldable material is deposited onto selected electronic components. The desiccant can be added in powder or granular form. Because the moldable material is impregnated with the desiccant, it provides slow absorption of moisture over the first 24 hours, followed by rapid absorption after approximately 48 hours. This slow initial absorption of moisture allows the remaining assembly steps to be performed outside the glovebox, which can reduce manufacturing costs. One example of a desiccant that can be added to the moldable material is a type 3A molecular sieve powder desiccant. Another example is an alkali metal aluminosilicate, in potassium form with a type A crystal structure. Molecular sieves are typically crystalline metal aluminosilicates with a three-dimensional interconnected network of silica and alumina tetrahedra. Another example of a desiccant that can be added to the moldable material includes silica.

[0102] In one test, it was found that the product contained desiccant powder. 653 saturates in approximately 72 hours at 27°C and 65% relative humidity, which is longer than the 24-48 hours required for saturation of conventional sheet desiccants. Adding a desiccant to the polymer prolongs the saturation time because the polymer slows down the transport of water to the desiccant. The saturation time may depend in part on the polymer's permeability.

[0103] Furthermore, typical manufacturing allows for the placement of a smaller amount of desiccant in the device. Incorporating desiccant material into moldable materials to increase the total amount of desiccant that can be placed is relatively straightforward. S-ICDs with sheet-like desiccant manufactured using existing methods have a desiccant absorption capacity of 60 mg of water vapor. Conversely, manufacturing using a blend of moldable materials and desiccant allows for the placement of a larger amount of desiccant, thus increasing the total absorption capacity; one test example achieved an increase of over 20% (reaching 73 mg of water vapor). In this example, the desiccant and... Mix at a ratio of 15:1. In other examples, the desiccant can be added to the moldable material (whether it is...) at a mixing ratio of, for example, 50:1, 40:1, 30:1, 20:1, 10:1, or 5:1. (or other materials)

[0104] Liquefied moldable materials can also be impregnated with a hydrogen getter material prior to molding. In some examples, both a desiccant and a hydrogen getter can be added. In other examples, only one of the desiccant or the hydrogen getter can be added to the moldable material. Some examples use a hydrogen getter made of polyisoprene, polybutadiene, polyvinylpropyne ether, polyacetylene, and polyvinylacetylene. The use of such getter materials is described in US PG Pub. No. 20150321013 entitled "IMPLANTABLE MEDICALDEVICE WITH A HYDROGEN GETTER," the disclosure of which is incorporated herein by reference.

[0105] Integrating desiccant and / or hydrogen getter directly into the moldable material eliminates the need for separate pads or insulation and / or sheets, dots, blocks, etc., for placing separate desiccant and / or hydrogen getter. This reduces manufacturing steps and the overall number of parts. If additional desiccant and / or hydrogen getter material is required, the moldable material can be formed with cavities to accommodate the additional material. In some examples, the manufacturing process can be completed without adding hydrogen getter material, in addition to the hydrogen getter material provided in the moldable material. In some examples, the manufacturing process can be completed without adding desiccant material, in addition to the desiccant material provided in the moldable material. Finally, in some examples, the manufacturing process can also be completed without omitting hydrogen getter material and desiccant material, in addition to providing one, another, or both of hydrogen getter material and desiccant material in the moldable material.

[0106] Incorporating moldable materials can slow down absorption during manufacturing, allowing for more assembly outside the glove box. Directly incorporating desiccants and / or hydrogen getters into the moldable material also reduces the amount of desiccant and hydrogen getter material required, as there is less air volume in the container and less moisture encapsulation due to the volume of the moldable material. The elimination of padding and / or insulation results in minimal increase in the mass of the moldable material. Furthermore, the molding process allows for faster and easier design changes, as the moldable material can easily accommodate the addition / reduction, swapping, or rearrangement of electronic components.

[0107] In some examples, the damping layer can be impregnated with a composite desiccant, which is selected to customize the moisture absorption characteristics. For example, a first and second desiccant with different properties can be used, where the first desiccant acts faster and the second slower, or other combinations. Various types and quantities of desiccants can be selected and combined to achieve specific, predetermined moisture absorption characteristics. The composite desiccant can control the rate of moisture absorption as the water vapor content inside the container changes. For example, a specific composite of desiccants can be used to achieve a distribution of the amount of moisture absorbed over different time periods. For instance, silica gel is very effective at high water vapor contents but poorly effective at low water vapor contents. Molecular sieves are effective at low water vapor contents, but their percentage of moisture absorption tends to plateau as the water vapor content increases. Calcium oxide is very effective at low water vapor contents and, compared to molecular sieves, has a high capacity for absorption at high water vapor percentages, but absorption is very slow. Therefore, the composite mixture achieves a balance between the manufacturing process, design requirements, and long-term capture of moisture generated by potential reactions inside the container.

[0108] In other examples, the damping layer can be impregnated with activated carbon or charcoal. Since the damping layer is in direct contact with the PCBA and / or battery, the inclusion of carbon or charcoal allows the damping layer to absorb certain organic and / or inorganic compounds, such as sulfur or electrolytes, from the surface of the operating circuit (PCBA) and / or battery.

[0109] The above detailed description includes reference to the accompanying drawings, which form a part of the detailed description. The drawings illustrate specific embodiments in which the invention can be practiced. These embodiments are also referred to herein as “examples.” Such examples may include elements other than those shown or described. However, the inventors also contemplate examples in which only those elements shown or described are provided. Furthermore, the inventors contemplate examples of any combination or arrangement of those elements (or one or more aspects thereof) shown or described herein, or with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.

[0110] In the event of any inconsistency between the usage in this document and any other document incorporated by reference, the usage in this document shall prevail. The above description is intended to be illustrative and not restrictive. For example, the above examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments may be used, as would be employed by one of ordinary skill in the art upon review of the above description. This abstract is provided to comply with 37 C. FR § 1.72(b) to allow the reader to quickly determine the nature of the technical disclosure and shall not be used to interpret or limit the scope or meaning of the claims.

[0111] Various features may be combined to simplify this disclosure. This should not be construed as meaning that any unclaimed disclosed features are necessary for any claim. Rather, the subject matter of the invention may not lie in all features of a particular disclosed embodiment. Therefore, the appended claims are thus incorporated into the detailed description as examples or embodiments, wherein each claim is an independent, separate embodiment, and these embodiments can be contemplated to be combined with each other in various combinations or arrangements. The scope of the invention should be determined by reference to the appended claims and the full scope of their equivalents.

Claims

1. An implantable medical device, comprising: The operating circuit for the implantable medical device includes a first group of multiple electrical components; A metal container, shaped to accommodate the operating circuit; as well as A damping layer, selectively disposed on and attached to the first group of multiple electrical components, provides electrical insulation to the first group of multiple electrical components and is configured to reduce the sensitivity of the first group of multiple electrical components to vibration; The operating circuit includes at least one second electrical component, and the damping layer is not disposed on the at least one second electrical component. The operating circuit includes a printed circuit board assembly, and the damping layer provides mechanical fixation of one or more of the battery, capacitor, energy transfer shield, speaker, telemetry component and charging coil to the printed circuit board assembly.

2. The implantable medical device according to claim 1, wherein, The damping layer is in direct contact with the container.

3. The implantable medical device according to claim 1, wherein, The damping layer is molded onto the first group of multiple electrical components.

4. The implantable medical device according to claim 3, wherein, The damping layer comprises thermoplastic or elastomer.

5. The implantable medical device according to claim 3, wherein, The damping layer does not contain epoxy resin.

6. The implantable medical device according to claim 3, wherein, The damping layer is a hot-melt polymer configured to be molded under low pressure.

7. The implantable medical device according to claim 3, wherein, The damping layer is impregnated with a desiccant.

8. The implantable medical device according to claim 3, wherein, The damping layer is impregnated with a hydrogen getter material.

9. The implantable medical device according to claim 3, wherein, The damping layer provides reliable fixation of the operating circuit to the container by adhering to it.

10. The implantable medical device according to claim 3, wherein, The damping layer forms one or more cavities, each cavity containing at least one of a desiccant, a hydrogen getter material, and an X-ray identification marker.

11. The implantable medical device according to any one of claims 1-10, wherein, The medical device has no metal layer between the damping layer and the container.

12. The implantable medical device according to any one of claims 1-10, wherein, The medical device has no insulating layer between the damping layer and the container.

13. A method of manufacturing an implantable medical device, comprising: A damping layer is molded onto at least a portion of a plurality of first electrical components of a printed circuit board assembly having a circuit board, thereby creating a covered operating circuit. as well as Place the covered operating circuit into the container of the medical device; The damping layer is configured to reduce internal movement of the printed circuit board assembly and / or components thereon, characterized in that the implantable medical device includes at least one second electrical component, and the damping layer is not disposed on the at least one second electrical component; The damping layer provides mechanical fixation of one or more of the battery, capacitor, energy transfer shield, speaker, telemetry component, and charging coil to the printed circuit board assembly.

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