Patent Description:
Implantable medical devices (IMDs) may be configured to sense physiological parameters and/or provide therapy and may include one or more electrodes for performing aspects of these functions. The overall usable volume enclosed within a housing of an IMD may be adjusted based on considerations of patient comfort and performance. A medical device according to the preamble of claim <NUM> is known from <CIT>.

The invention is defined in claims <NUM> and <NUM>. Embodiments of the disclosure include an implantable medical device having a housing designed to increase internal volume and allow for welding of two portions thereof together without using a separate weld ring.

While multiple embodiments are disclosed, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosure.

While the disclosed subject matter is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the disclosed subject matter to the particular embodiments described. On the contrary, the disclosed subject matter is intended to cover all modifications, equivalents, and alternatives falling within the scope of the disclosed subject matter as defined by the appended claims.

As the terms are used herein with respect to ranges of measurements (such as those disclosed immediately above), "about" and "approximately" may be used, interchangeably, to refer to a measurement that includes the stated measurement and that also includes any measurements that are reasonably close to the stated measurement, but that may differ by a reasonably small amount such as will be understood, and readily ascertained, by individuals having ordinary skill in the relevant arts to be attributable to measurement error, differences in measurement and/or manufacturing equipment calibration, human error in reading and/or setting measurements, adjustments made to optimize performance and/or structural parameters in view of differences in measurements associated with other components, particular implementation scenarios, imprecise adjustment and/or manipulation of objects by a person or machine, and/or the like.

Although the term "block" may be used herein to connote different elements illustratively employed, the term should not be interpreted as implying any requirement of, or particular order among or between, various steps disclosed herein unless and except when explicitly referring to the order of individual steps.

<FIG> is a schematic illustration of a system <NUM> including an implantable medical device (IMD) <NUM> implanted within a patient's body <NUM> and configured to communicate with a receiving device <NUM>. In embodiments, the IMD <NUM> may be implanted subcutaneously within an implantation location or pocket in the patient's chest or abdomen and may be configured to monitor (e.g., sense and/or record) physiological parameters associated with the patient's heart <NUM>. In embodiments, the IMD <NUM> may be an implantable cardiac monitor (ICM) (e.g., an implantable diagnostic monitor (IDM), an implantable loop recorder (ILR), etc.) configured to record physiological parameters such as, for example, one or more cardiac activation signals, heart sounds, blood pressure measurements, oxygen saturations, and/or the like. In embodiments, the IMD <NUM> may be configured to monitor physiological parameters that may include one or more signals indicative of a patient's physical activity level and/or metabolic level, such as an acceleration signal. In embodiments, the IMD <NUM> may be configured to monitor physiological parameters associated with one or more other organs, systems, and/or the like. The IMD <NUM> may be configured to sense and/or record at regular intervals, continuously, and/or in response to a detected event. In embodiments, such a detected event may be detected by one or more sensors of the IMD <NUM>, another IMD (not shown), an external device (e.g., the receiving device <NUM>), and/or the like. In addition, the IMD <NUM> may be configured to detect a variety of physiological signals that may be used in connection with various diagnostic, therapeutic, and/or monitoring implementations.

For example, the IMD <NUM> may include sensors or circuitry for detecting respiratory system signals, cardiac system signals, and/or signals related to patient activity. In embodiments, the IMD <NUM> may be configured to sense intrathoracic impedance, from which various respiratory parameters may be derived, including, for example, respiratory tidal volume and minute ventilation. Sensors and associated circuitry may be incorporated in connection with the IMD <NUM> for detecting one or more body movement or body posture and/or position related signals. For example, accelerometers and/or GPS devices may be employed to detect patient activity, patient location, body orientation, and/or torso position.

For purposes of illustration, and not of limitation, various embodiments of devices that may be used to record physiological parameters in accordance with the present disclosure are described herein in the context of IMDs that may be implanted under the skin in the chest region of a patient. In embodiments, however, the IMD <NUM> may include any type of IMD, any number of different components of an implantable system, and/or the like having a housing and being configured to be implanted in a patient's body <NUM>. For example, the IMD <NUM> may include a control device, a monitoring device, a pacemaker, an implantable cardioverter defibrillator (ICD), a cardiac resynchronization therapy (CRT) device and/or the like, and may be an implantable medical device known in the art or later developed, for providing therapy and/or diagnostic data about the patient's body and/or the IMD <NUM>. In various embodiments, the IMD <NUM> may include both defibrillation and pacing/CRT capabilities (e.g., a CRT-D device).

As shown, the IMD <NUM> may include a housing <NUM> having two electrodes <NUM> and <NUM> coupled thereto. According to embodiments, the IMD <NUM> may include any number of electrodes (and/or other types of sensors such as, e.g., thermometers, barometers, pressure sensors, optical sensors, motion sensors, and/or the like) in any number of various types of configurations, and the housing <NUM> may include any number of different shapes, sizes, and/or features. In embodiments, the IMD <NUM> may be configured to sense physiological parameters and record the physiological parameters. For example, the IMD <NUM> may be configured to activate (e.g., periodically, continuously, upon detection of an event, and/or the like), record a specified amount of data (e.g., physiological parameters) in a memory, and communicate that recorded data to a receiving device <NUM>. In the case of an IDM, for example, the IMD <NUM> may activate, record cardiac signals for a certain period of time, deactivate, and activate to communicate the recorded signals to the receiving device <NUM>.

In various embodiments, the receiving device <NUM> may be, for example, a programmer, controller, patient monitoring system, and/or the like. Although illustrated in <FIG> as an external device, the receiving device <NUM> may include an implantable device configured to communicate with the IMD <NUM> that may, for example, be a control device, another monitoring device, a pacemaker, an implantable defibrillator, a cardiac resynchronization therapy (CRT) device, and/or the like, and may be an implantable medical device known in the art or later developed, for providing therapy and/or diagnostic data about the patient and/or the IMD <NUM>. In various embodiments, the IMD <NUM> may be a pacemaker, an implantable cardioverter defibrillator (ICD) device, or a cardiac resynchronization therapy (CRT) device. In various embodiments, the IMD <NUM> may include both defibrillation and pacing/CRT capabilities (e.g., a CRT-D device).

The system <NUM> may be used to implement coordinated patient measuring and/or monitoring, diagnosis, and/or therapy in accordance with embodiments of the disclosure. The system <NUM> may include, for example, one or more patient-internal medical devices, such as an IMD <NUM>, and one or more patient-external medical devices, such as receiving device <NUM>. In embodiments, the receiving device <NUM> may be configured to perform monitoring, and/or diagnosis and/or therapy functions external to the patient (i.e., not invasively implanted within the patient's body). The receiving device <NUM> may be positioned on the patient, near the patient, or in any location external to the patient.

In embodiments, the IMD <NUM> and the receiving device <NUM> may communicate through a wireless link. For example, the IMD <NUM> and the receiving device <NUM> may be coupled through a short-range radio link, such as Bluetooth, IEEE <NUM>, and/or a proprietary wireless protocol. The communications link may facilitate uni-directional and/or bi-directional communication between the IMD <NUM> and the receiving device <NUM>. Data and/or control signals may be transmitted between the IMD <NUM> and the receiving device <NUM> to coordinate the functions of the IMD <NUM> and/or the receiving device <NUM>. In embodiments, patient data may be downloaded from one or more of the IMD <NUM> and the receiving device <NUM> periodically or on command. The physician and/or the patient may communicate with the IMD <NUM> and the receiving device <NUM>, for example, to acquire patient data or to initiate, terminate, or modify recording and/or therapy.

The illustrative system <NUM> shown in <FIG> is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the subject matter disclosed throughout this disclosure. Neither should the illustrative system <NUM> be interpreted as having any dependency or requirement related to any single component or combination of components illustrated in <FIG>. For example, in embodiments, the illustrative system <NUM> may include additional components. Additionally, any one or more of the components depicted in <FIG> can be, in embodiments, integrated with various ones of the other components depicted therein (and/or components not illustrated). Any number of other components or combinations of components can be integrated with the illustrative system <NUM> depicted in <FIG>, all of which are considered to be within the ambit of this disclosure.

<FIG> is a perspective view of an implantable medical device (IMD) <NUM>, in accordance with embodiments of the disclosure. The IMD <NUM> may be, or may be similar to, the IMD <NUM> depicted in <FIG>. As shown, the IMD <NUM> may include a header <NUM> arranged at or near a first end <NUM> of a core assembly <NUM>. A battery assembly <NUM> (which may include one or more batteries) is arranged near a second end <NUM> of the core assembly <NUM>. The header <NUM> includes a housing 202A that encloses an interior region 202B. The header <NUM> may house various circuitry components within its interior. The housing 202A may contact a patient's bodily tissue when the IMD <NUM> is subcutaneously implanted in an implantation location or pocket in the patient's chest or abdomen. The interior region 202B of the header <NUM> may house circuit components (e.g., an electrode <NUM> and an antenna <NUM>) positioned and supported by a scaffold assembly <NUM>. As shown, the IMD <NUM> may include, in addition to the electrode <NUM>, an electrode <NUM> disposed at an end of the battery assembly <NUM>. In embodiments, the electrode <NUM> may be integrated with the battery assembly <NUM>, a housing of the battery assembly <NUM>, and/or the like. In order to enable sensing of physiological parameters within the patient, the electrode <NUM> may be positioned to be flush with an interior surface of the housing 202A of the header <NUM>. In other instances, the electrode <NUM> may be positioned by the scaffold assembly <NUM> to form a portion of an exterior surface of the housing 202A of the header <NUM>.

As shown in <FIG>, the core assembly <NUM> includes a core circuitry assembly <NUM> enclosed within a core assembly housing <NUM>. The core assembly housing <NUM> is coupled, at the first end <NUM>, to a first feed-through assembly <NUM>, and coupled, at the second end <NUM>, to a second feed-through assembly <NUM>. The feed-through assembly <NUM> may be configured to provide a throughput for connections configured to connect the circuitry components of the header <NUM> (e.g., the electrode <NUM> and the antenna <NUM>) to the core circuitry assembly <NUM>. Similarly, the feed-through assembly <NUM> may be configured to provide a throughput for connections configured to connect one or more batteries (e.g., which are a part of the battery assembly <NUM>) and/or the electrode <NUM> to the core circuitry assembly <NUM>.

As illustrated in <FIG>, the core assembly housing <NUM> includes a first portion <NUM> configured to be coupled to a second portion <NUM> along a weld seam <NUM>. The first portion <NUM> and second portion <NUM> may be coupled together by laser welding, seam welding, and/or the like. In embodiments, a separate weld ring does not need to be used, as a feature of at least one of the first and second portions <NUM> and <NUM> acts as a weld ring, protecting the core circuitry assembly <NUM> from the welding energy (e.g., heat, laser, etc.).

For example, and as described in further detail below, the first portion <NUM> may include one or more weld joint features configured to be positioned adjacent to one or more corresponding weld joint features on the second portion <NUM> in preparation for welding. In embodiments, for example, the first portion <NUM> and the second portion <NUM> may include a continuous, curved wall (such as, for example, in an implementation of a pacemaker or other implantable pulse generator), a curved wall and a straight wall, a number of curved walls, a number of straight walls, and/or any number of different combinations of these. Each wall of the first portion <NUM> that is configured to be coupled to a corresponding wall of the second portion <NUM> may include at least one weld joint feature configured to be positioned adjacent to at least one corresponding feature on the second portion <NUM>, and, in embodiments, vice-versa.

Each weld joint feature includes a thinned leading edge (the edge that is configured to be coupled to the corresponding edge of the other portion of the housing) of a wall. That is, the edge of the wall is thinner than other sections of the wall. In this manner, an edge of one of the two portions can pass over the corresponding edge of the other portion when the two portions are positioned around the core circuitry assembly in preparation for welding. In this manner, the volume enclosed within the housing may be maximized, and the lower edge (i.e., the edge closer to the core circuitry assembly) acts as a weld ring, protecting the core circuitry assembly from the applied energy (e.g., heat, laser, etc.) during a welding procedure. In embodiments, the weld joint feature may include a coined edge of a wall, a flange, and/or the like.

As shown, for example, in <FIG> and <FIG>, the first portion <NUM> of the core assembly housing <NUM> includes a side wall <NUM>, a lower wall <NUM>, and an upper wall <NUM>. The lower wall <NUM> and the upper wall <NUM> each extend, perpendicularly (or at least approximately perpendicularly) in a direction away from an inside surface 234A of the side wall <NUM>. As shown, the lower wall <NUM> is coupled to the side wall <NUM> by a curved corner portion <NUM>, and the upper wall <NUM> is coupled to the side wall <NUM> by a curved corner portion <NUM>. In embodiments, the curved corner portions <NUM> and <NUM> may be integrated with the lower and upper walls <NUM> and <NUM>, respectively, the side wall <NUM>, and/or the like. That is, for example, the first portion <NUM> may be a single piece of metal, formed in a press or a mold. In embodiments, the curved corner portions <NUM> and <NUM> may be separate components. The curved corner portions <NUM> and <NUM> each may be designed to have any desirable radius of curvature. For example, the curved corner portions <NUM> and <NUM> each may be configured to have a radius of curvature that provides a desired amount of volume enclosed within the core assembly housing <NUM>.

As illustrated, for example, in <FIG> and <FIG>, the lower wall <NUM> includes a flange <NUM> that is recessed with respect to an inside surface <NUM> of the lower wall <NUM>, and that extends from a first end <NUM> of the first portion <NUM> to a second end <NUM> thereof. The flange <NUM> may be a thinned portion of the lower wall <NUM>. In embodiments, the flange <NUM> may be welded to the lower wall <NUM>. Similarly, the upper wall <NUM> includes a flange <NUM> that is recessed with respect to an inside surface <NUM> of the upper wall <NUM>, and that extends from the first end <NUM> of the first portion <NUM> to the second end <NUM> thereof. The flange <NUM> may be a thinned portion of the upper wall <NUM>. In embodiments, the flange <NUM> may be welded to the upper wall <NUM>.

As is also shown, for example, in <FIG> and <FIG>, the second portion <NUM> of the core assembly housing <NUM> includes a side wall <NUM>, a lower wall <NUM>, and an upper wall <NUM>. The lower wall <NUM> and the upper wall <NUM> each extend, perpendicularly (or at least approximately perpendicularly) in a direction away from an inside surface 256A of the side wall <NUM>. As shown, the lower wall <NUM> is coupled to the side wall <NUM> by a curved corner portion <NUM>, and the upper wall <NUM> is coupled to the side wall <NUM> by a curved corner portion <NUM>. In embodiments, the curved corner portions <NUM> and <NUM> may be integrated with the lower and upper walls <NUM> and <NUM>, respectively, the side wall <NUM>, and/or the like. That is, for example, the second portion <NUM> may be a single piece of metal, formed in a press or a mold. In embodiments, the curved corner portions <NUM> and <NUM> may be separate components. The curved corner portions <NUM> and <NUM> each may be designed to have any desirable radius of curvature such as, for example, a radius of curvature that is identical or similar to the radius of curvature of each of the curved corner portions <NUM> and <NUM>. For example, the curved corner portions <NUM> and <NUM> each may be configured to have a radius of curvature that provides a desired amount of volume enclosed within the core assembly housing <NUM>.

As illustrated, for example, in <FIG> and <FIG>, the lower wall <NUM> includes a flange <NUM> that is recessed with respect to an outside surface <NUM> of the lower wall <NUM>, and that extends from a first end <NUM> of the second portion <NUM> to a second end <NUM> thereof. The flange <NUM> may be a thinned portion of the lower wall <NUM>. In embodiments, the flange <NUM> may be welded to the lower wall <NUM>. Similarly, the upper wall <NUM> includes a flange <NUM> that is recessed with respect to an outside surface <NUM> of the upper wall <NUM>, and that extends from the first end <NUM> of the second portion <NUM> to the second end <NUM> thereof. The flange <NUM> may be a thinned portion of the upper wall <NUM>. In embodiments, the flange <NUM> may be welded to the upper wall <NUM>.

The core assembly housing <NUM> may also include notches <NUM> defined in the first and second ends <NUM> and <NUM>, respectively, of the first portion <NUM>, and extending from the inside surface 234A to the outside surface 234B of the side wall <NUM>. Similarly, the core assembly housing <NUM> may also include notches <NUM> defined in the first and second ends <NUM> and <NUM>, respectively, of the second portion <NUM>, and extending from the inside surface 256A to the outside surface 256B of the side wall <NUM>. The notches <NUM> and <NUM> may be an artifact of a progressive die manufacturing process in which the first and second portions <NUM> and <NUM> of the core assembly housing <NUM> are produced in a continuous strip and formed into shape in successive operations. The notches <NUM> and <NUM> may be left when the first and second portions <NUM> and <NUM> are broken away from the strip. In embodiments, the strip may be configured such that the notches are small enough to be consumed in the weld pool when the core assembly housing <NUM> is welded to the first and second feedthrough assemblies <NUM> and <NUM>. For example, in embodiments, the notches <NUM> and <NUM> may extend into the portions <NUM> and <NUM> by less than or equal to approximately <NUM> inches.

As shown in <FIG>, when the first portion <NUM> is brought together with the second portion <NUM>, the flange <NUM> is positioned adjacent to the flange <NUM>, and the flange <NUM> is positioned adjacent to the flange <NUM>. The portions <NUM> and <NUM> are welded together along the flanges <NUM>, <NUM> and <NUM>, <NUM> without the necessity of inserting a separate weld ring, since the flange <NUM> and flange <NUM> protect the core circuitry assembly <NUM>, each flange <NUM> and <NUM> acting as an integrated weld ring.

As shown in <FIG>, the flange <NUM> may be configured such that a first section <NUM> of the inside surface <NUM> of the lower wall <NUM> of the first portion <NUM> of the core assembly housing <NUM> is at least approximately continuous with the inside surface 234A of the side wall <NUM>. A second section <NUM> of the inside surface <NUM> of the lower wall <NUM> may be oriented at an angle with respect to the first section <NUM> and may extend from an outside boundary of the first section <NUM> downward to a third section <NUM> of the inside surface <NUM>. The third section <NUM> of the inside surface <NUM> may be oriented parallel to, or at least approximately parallel to, the first section <NUM>. Thus, the second section <NUM> may be configured as a ramp extending between the first and third sections <NUM> and <NUM>.

Similarly, the flange <NUM> may be configured such that a first section <NUM> of the inside surface <NUM> of the upper wall <NUM> of the first portion <NUM> of the core assembly housing <NUM> is at least approximately continuous with the inside surface 234A of the side wall <NUM>. A second section <NUM> of the inside surface <NUM> of the upper wall <NUM> may be oriented at an angle with respect to the first section <NUM> and may extend from an outside boundary of the first section <NUM> upward to a third section <NUM> of the inside surface <NUM>. The third section <NUM> of the inside surface <NUM> may be oriented parallel to, or at least approximately parallel to, the first section <NUM>. Thus, the second section <NUM> may be configured as a ramp extending between the first and third sections <NUM> and <NUM>.

In a similar manner, the flange <NUM> may be configured such that a first section <NUM> of the outside surface <NUM> of the lower wall <NUM> of the second portion <NUM> of the core assembly housing <NUM> is at least approximately continuous with the outside surface 256B of the side wall <NUM>. A second section <NUM> of the outside surface <NUM> of the lower wall <NUM> may be oriented at an angle with respect to the first section <NUM> and may extend from the first section <NUM> upward to a third section <NUM> of the outside surface <NUM>. The third section <NUM> of the outside surface <NUM> may be oriented parallel to, or at least approximately parallel to, the first section <NUM>. Thus, the second section <NUM> may be configured as a ramp extending between the first and third sections <NUM> and <NUM>.

Additionally, the flange <NUM> may be configured such that a first section <NUM> of the outside surface <NUM> of the upper wall <NUM> of the second portion <NUM> of the core assembly housing <NUM> is at least approximately continuous with the outside surface 256B of the side wall <NUM>. A second section <NUM> of the outside surface <NUM> of the upper wall <NUM> may be oriented at an angle with respect to the first section <NUM> and may extend from the first section <NUM> downward to a third section <NUM> of the outside surface <NUM>. The third section <NUM> of the outside surface <NUM> may be oriented parallel to, or at least approximately parallel to, the first section <NUM>. Thus, the second section <NUM> may be configured as a ramp extending between the first and third sections <NUM> and <NUM>.

During assembly, as shown in <FIG>, when the first portion <NUM> and second portion <NUM> are brought together, a leading edge <NUM> of the lower wall <NUM> of the first portion <NUM> may be configured to be positioned adjacent to the second section <NUM> of the outside surface <NUM> of the lower wall <NUM> of the second portion <NUM>, and a leading edge <NUM> of the lower wall <NUM> of the second portion <NUM> may be configured to be positioned adjacent to the second section <NUM> of the inside surface <NUM> of the lower wall <NUM> of the first portion <NUM>, forming a gap <NUM>. Similarly, a leading edge <NUM> of the upper wall <NUM> of the first portion <NUM> may be configured to be positioned adjacent to the second section <NUM> of the outside surface <NUM> of the upper wall <NUM> of the second portion <NUM>, and a leading edge <NUM> of the upper wall <NUM> of the second portion <NUM> may be configured to be positioned adjacent to the second section <NUM> of the inside surface <NUM> of the upper wall <NUM> of the first portion <NUM>, forming a gap <NUM>. In this manner, the third sections <NUM>, <NUM>, <NUM>, and <NUM> may be the weld surfaces, with the third sections <NUM> and <NUM> functioning as a weld ring, thereby protecting the core circuitry assembly <NUM> from the laser, heat, and/or other welding energy.

The illustrative IMD <NUM> shown in <FIG> and the illustrative core assembly housing <NUM> shown in <FIG> is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the subject matter disclosed throughout this disclosure. Neither should the illustrative IMD <NUM> or illustrative core assembly housing <NUM> be interpreted as having any dependency or requirement related to any single component, feature, or combination of components or features illustrated in <FIG> or <FIG>. For example, in embodiments, the illustrative IMD <NUM> and/or illustrative core assembly housing <NUM> may include different and/or additional components and/or features. Any number of other components, features, or combinations of components or features can be integrated with the illustrative IMD <NUM> depicted in <FIG> and/or illustrative core assembly housing <NUM> depicted in <FIG>, all of which are considered to be within the ambit of this disclosure.

Additionally, any one or more of the components and/or features depicted in <FIG> and <FIG> can be, in embodiments, integrated with various ones of the other components and/or features depicted therein (and/or components and/or features not illustrated). For example, instead of the flanges <NUM>, <NUM>, <NUM>, and <NUM>, the weld joint features may be wedge-shaped edges. That is, for example, the second section <NUM> and the third section <NUM> of the inside surface of the lower wall <NUM> of the first portion <NUM> may be integrated and include an at least approximately continuous decrease in thickness from the outside boundary of the first section <NUM> to the leading edge <NUM>. Similarly, the second section <NUM> and the third section <NUM> of the inside surface of the upper wall <NUM> of the first portion <NUM> may be integrated and include an at least approximately continuous decrease in thickness from the outside boundary of the first section <NUM> to the leading edge <NUM>; the second section <NUM> and the third section <NUM> of the outside surface <NUM> of the lower wall <NUM> of the second portion <NUM> may be integrated and include an at least approximately continuous decrease in thickness from the outside boundary of the first section <NUM> to the leading edge <NUM>; and the second section <NUM> and the third section <NUM> of the outside surface <NUM> of the upper wall <NUM> of the second portion <NUM> may be integrated and include an at least approximately continuous decrease in thickness from the outside boundary of the first section <NUM> to the leading edge <NUM>.

Additionally, in some embodiments, the core assembly housing <NUM> may include weld joint feature or features on only one portion. That is, for example, embodiments of the core assembly housing <NUM> may include only the flange <NUM> (or a wedge-shaped edge) and flange <NUM> (or a wedge-shaped edge) on the second portion <NUM>, in which case the flanges <NUM> and <NUM> (or wedge-shaped edges) may include a surface extending farther inward (toward the core circuitry assembly) than the inside surfaces of the lower and upper walls <NUM> and <NUM>, respectively.

Moreover, as used herein, the terms "side wall," "lower wall," "upper wall," "upward," and "downward" are used to refer to the specific features to which they refer, but are characterized in the context of the illustrations for clarity and to describe relative orientations of features with respect to other features, and are not intended to imply any particular orientation of the IMD <NUM>, or absolute (or preferred) orientations of features thereof. That is, for example, even if the IMD <NUM> were to be rotated around a longitudinal axis such that the outer surface 234B of the side wall <NUM> was parallel to a horizontal plane, the side wall <NUM> would still be referred to, for the purposes of this disclosure, as a "side wall.

Embodiments of an IMD having a core assembly housing configured to be assembled without the use of a weld ring are described above, and include configurations designed to enhance the internal volume of the IMD. <FIG> is a flow diagram depicting an illustrative method <NUM> of manufacturing an IMD in accordance with embodiments of the disclosure. The IMD may be, for example, the IMD <NUM> depicted in <FIG>, the IMD <NUM> depicted in <FIG>, and/or the like.

Embodiments of the method <NUM> include providing a core circuitry assembly (block <NUM>), which may include obtaining and/or assembling one or more portions of a core circuitry assembly such as, for example, by assembling an integrated circuit, coupling circuitry to a liner, and/or the like. The method <NUM> also may include providing a header (block <NUM>), which may include obtaining and/or assembling one or more portions of a header such as, for example, by arranging circuit components (e.g., an electrode and an antenna) on a scaffold assembly and enclosing the scaffold assembly within a header assembly housing. The method <NUM> may also include providing a battery assembly (block <NUM>) and providing feed-through assemblies (block <NUM>), which may include obtaining and/or assembling a battery assembly and/or a first and second feed-through assembly.

As depicted in <FIG>, embodiments of the method <NUM> also include coupling the feed-through assemblies to the core circuitry assembly (block <NUM>), coupling the header to a first feed-through assembly (block <NUM>), and coupling the battery assembly to a second feed-through assembly (block <NUM>). In embodiments, the method <NUM> includes creating first and second portions of a core assembly housing, having weld joint features (block <NUM>). In embodiments, the core assembly housing portions may be molded, cut, and/or the like, and may be identical or similar to the core assembly housing portions <NUM> and <NUM> depicted in <FIG> and <FIG>. As shown in <FIG>, embodiments of the method <NUM> also include positioning the core assembly housing portions around the core circuitry assembly (block <NUM>) and welding the core assembly housing portions together along the weld joint features (block <NUM>).

Claim 1:
A medical device (<NUM>) comprising:
a core circuitry assembly (<NUM>); and
a core assembly housing (<NUM>) configured to enclose the core circuitry assembly (<NUM>), the core assembly housing (<NUM>) comprising:
a first portion (<NUM>) comprising:
a first side wall (<NUM>), the first side wall (<NUM>) comprising first and second ends (<NUM>, <NUM>);
a first lower wall (<NUM>) coupled to the first side wall (<NUM>) by a first curved corner portion (<NUM>) and extending in a direction away from the inside surface (234A) of the first side wall (<NUM>); and
a first upper wall (<NUM>) coupled to the first side wall (<NUM>) by a second curved corner portion (<NUM>) and extending in a direction away from the inside surface (234A) of the first side wall (<NUM>); and
a second portion (<NUM>) configured to be coupled to the first portion (<NUM>) along a weld seam (<NUM>), the second portion (<NUM>) comprising
a second side wall (<NUM>), the second wall (<NUM>) comprising first and second ends (<NUM>, <NUM>);
a second lower wall (<NUM>) coupled to the second side wall (<NUM>) by a third curved corner portion (<NUM>) and extending in a direction away from the inside surface (256A) of the second side wall (<NUM>); and
a second upper wall (<NUM>) coupled to the side wall (<NUM>) by a second curved corner portion (<NUM>) and extending in a direction away from the inside surface (256A) of the second side wall (<NUM>). and
at least one weld joint feature, wherein the at least one weld joint feature includes a thinned section of the second portion (<NUM>),
characterised in that notches (<NUM>, <NUM>) are defined in said first and second ends (<NUM>, <NUM>, <NUM>, <NUM>) extending from an inside surface (234A, 256A) to an outside surface (234B, 256B) of said first and second side walls (<NUM>).