Housing for an implantable medical device

Abstract

A device housing for an IMD is proposed, wherein the device housing has: a front side; a flat end face, which is arranged perpendicular to the front side and adjoins the straight upper edge of the front side; wherein the front side has a maximum width (Bmax) measured parallel to the straight upper edge and a maximum height (Hmax) measured perpendicular to the straight upper edge, and is characterized in that the ratio R of the maximum width (Bmax) to the maximum height (Hmax), i.e., Bmax / Hmax, has a value between 1.05 and 1.35.

Description

Technical Field

[0001] The present invention relates to a housing for an implantable medical device (IMD). Background Art

[0002] The housing for an IMD houses the most important device components and protects them from the surrounding environment of the implantation site. The device housing may have external interfaces, such as for electrically connecting and mechanically connecting device components (e.g., stimulation electrodes for a pacemaker implant) or for sensor interfaces for measuring human parameters.

[0003] There are IMDs whose device housings are implanted in a skin pocket or tissue pocket of a patient (e.g., for a cardiac pacemaker implant or a dorsal marker stimulator). The size of the device housing should be set as small as possible and shaped in such a way that it does not cause discomfort to the patient. In the prior art, a flat circular housing shape is known, which causes a small bulge with minimal protrusion in the skin.

[0004] Cardiac pacemakers, implantable cardioverter-defibrillators (ICDs) or CRT (cardiac resynchronization therapy) devices generally have a flat circular housing made of metal. The housing is mechanically connected to a head component (hereinafter referred to as the head) at the end side, which is generally made of potted epoxy resin and provides a terminal for the electrode wire. The electrical conductor enters the head from the device housing up to the terminal for the electrode wire, and thus ensures an electrical connection between the electrode and components provided inside the housing such as the device processor, the battery or the shock capacitor in an ICD. The device housing with the head is implanted in a skin pocket or tissue pocket in the upper thoracic region, above the ribs and below the collarbone. The combination of the device housing and the head is hereinafter referred to as the housing assembly.

[0005] In the prior art, cardiac pacemakers, ICDs and CRT devices are known, where the housing assembly consisting of the device housing and the head is flat and has a circular outer contour. The problem with such a housing assembly is that it may easily rotate in the skin pocket or tissue pocket. The electrode wire connected to the head then rotates along with it, and thus electrode breakage may occur.

[0006] It is also known that the following housing assembly, where the instrument housing is wider than it is tall, or taller than it is wide. The disadvantage of such a housing assembly is that the instrument housing is prone to "rocking" on the patient's ribs. The rocking is determined by the space present between the patient's ribs and the instrument housing, which is relatively large for such a housing assembly because the instrument housing has relatively long and flat sides that do not follow the rib contour. This "rocking" is particularly prominent and uncomfortable, especially for patients with a small chest cavity whose rib contour has a relatively small radius of curvature.

[0007] When implanting such a housing assembly, a relatively small incision is made in the patient's skin, which has the following disadvantage: the doctor has little freedom in designing the skin pocket or tissue pocket. Summary of the Invention

[0008] The present invention is based on the following tasks: to provide an instrument housing for an IMD that allows the patient to wear it comfortably under the skin, i.e., without pain and with substantially no perceptible tension and pulling force. The tasks of the present invention also include providing an instrument housing for an IMD that rocks as little as possible when implanted on the patient's ribs.

[0009] Another task of the present invention is to provide an instrument housing for an IMD that is not prone to rotation in the implanted state.

[0010] Another task of the present invention is to provide an instrument housing for an IMD that can be implanted simply, quickly, and controllably.

[0011] The above tasks are accomplished by the instrument housing of the present invention according to claim 1, the housing assembly including the instrument housing according to claim 12, and the method for implanting the housing assembly according to claim 14.

[0012] Advantageous embodiments of the present invention can be found in the dependent claims.

[0013] According to the solution of the present invention, an instrument housing for an IMD is proposed, wherein the instrument housing has:

[0014] - a front face,

[0015] - a flat end face that is arranged perpendicular to the front face and meets the straight upper edge of the front face,

[0016] - wherein the front face has a maximum width (Bmax) measured parallel to the straight upper edge and a maximum height (Hmax) measured perpendicular to the straight upper edge,

[0017] Characterized in that the ratio R of the maximum width (Bmax) to the maximum height (Hmax), i.e., Bmax / Hmax, has a value between 1.05 and 1.35.

[0018] In this way, according to the proposed, the instrument housing has an optimal geometry to allow for a comfortable fit for the patient, i.e., to avoid or even significantly reduce "swaying" on the rib, since the instrument housing does not have an elongated surface. At the same time, rotation within the skin pocket or tissue pocket is prevented, since the housing is not circular.

[0019] According to an advantageous embodiment, the ratio R, i.e., the value of Bmax / Hmax, is between 1.1 and 1.30, or between 1.15 and 1.275, or between 1.2 and 1.275, or is 1.25.

[0020] Furthermore, according to an advantageous aspect of the present invention, the maximum width (Bmax) of the front face is 40 mm to 70 mm, or 50 mm to 65 mm, or 55 mm to 65 mm, or 60 mm.

[0021] According to other embodiments of the present invention, the maximum height (Hmax) of the front face has a value of 40 mm to 70 mm, or 40 mm to 60 mm, or 45 mm to 55 mm, or 45 mm to 52 mm, or 48 mm.

[0022] The stated dimensions for the ratio R, Bmax or Hmax have proven effective for accomplishing the above tasks.

[0023] Furthermore, according to another aspect of the present invention, the instrument housing has a maximum thickness Dmax, where the thickness is measured perpendicular to the plane of the front face, and the maximum thickness has a value of 9 mm to 15 mm, or 9 mm to 12 mm, or 10 mm to 11 mm, or 10 mm.

[0024] The thickness allows for an ergonomic thin instrument housing with sufficient internal volume for mounting instrument components, while also combining with the proposed other geometries for the instrument housing.

[0025] According to other advantageous embodiments of the solution of the present invention, the instrument housing has a back face, which is arranged congruently and oppositely relative to the front face, and wherein the flat end face meets the straight upper edge of the back face.

[0026] The instrument housing may also include two housing covers, where the first housing cover has the front face, the second housing cover has the back face, and the first and second housing covers are symmetrically configured.

[0027] In this way, the symmetrical structure of the device housing is allowed. The symmetrical structure is advantageous for patients who have the IMD implanted on the right side rather than on the left side. Thus, the IMD can be easily flipped by the device housing of the present invention and can be implanted in a mirror-symmetrical manner, at which time it has the same performance for the patient in terms of wearing comfort as for a conventional patient with an IMD implanted on the left side.

[0028] Furthermore, according to an advantageous aspect of the present invention, the outer contour of the front face of the device housing has a plurality of curves with at least two different radii of curvature. At this time, the maximum radius of curvature does not exceed 12 cm or 11 cm or 10 cm or 9.5 cm.

[0029] By selecting the radius of curvature, it is ensured that the implant does not have an elongated surface, thereby preventing "rocking" on the rib.

[0030] According to an advantageous embodiment of the present invention, the ratio of the area of the front face to the area of the rectangle defined by the maximum width (Bmax) and the maximum height (Hmax) of the front face, i.e., area(front face) / area(rectangle), can be at least 0.6, or at least 0.7, or at least 0.75, or at least 0.8, or at least 0.85, or at least 0.9, or at least 0.95.

[0031] Furthermore, the ratio of the area of the front face to the area of the ellipse defined by the maximum width (Bmax) and the maximum height (Hmax) of the front face, i.e., area(front face) / area(ellipse), can be at most 1.5, or at most 1.4, or at most 1.3, or at most 1.2, or at most 1.15, or at most 1.1.

[0032] By selecting according to the proposed "filling factor", it is ensured that on the one hand, the design of the device housing remains "similar to a circle" or at least "similar to an ellipse", thereby preventing sharp corners and elongated surfaces of the contour to enhance wearing comfort and avoid "rocking".

[0033] According to other aspects of the present invention, the device housing has rounded edges. This improves the wearing comfort of the patient.

[0034] In addition, according to other embodiments, a housing assembly for an IMD is proposed, which includes the device housing of the present invention and a head (3). The head is connected to the device housing at the flat end face of the device housing.

[0035] According to an advantageous embodiment of the present invention, the IMD is a cardiac pacemaker, an implantable cardioverter defibrillator or a CRT device.

[0036] Furthermore, a method for implanting the housing assembly of the present invention is proposed. The method includes the following steps:

[0037] - Provide the housing assembly,

[0038] - Cut the patient's body tissue below the collarbone by means of an incision,

[0039] - Prepare a tissue pocket having a size substantially corresponding to the volume of the housing assembly,

[0040] - Place the instrument housing into the tissue pocket,

[0041] - Close the tissue pocket.

[0042] According to an advantageous aspect of the method of the present invention, the length of the incision is less than or equal to the maximum width (Bmax) of the front surface of the instrument housing. Alternatively, the length of the incision can be less than or equal to the maximum height (Hmax) of the front surface plus the head height. In this way, an incision of optimal length is applied to prepare the skin pocket or tissue pocket.

[0043] Other advantageous embodiments can be obtained from the drawings and the description of the drawings. The drawings are used to illustrate different aspects of the present invention and should not be regarded as restrictive of the subject matter to be protected. Description of the Drawings

[0044] Figure 1 Schematic diagram showing the housing assembly according to the present invention.

[0045] Figure 2 Side view schematic diagram showing the housing assembly according to the present invention.

[0046] Figure 3 Schematic diagram showing the curve radius for determining the contour of the instrument housing.

[0047] Figure 4 Schematic diagram showing the determination of the filling coefficient for the front surface area of the instrument housing.

[0048] Figure 5 Schematic diagram showing the determination of the filling coefficient for the front surface area of the instrument housing. Detailed Description of the Invention

[0049] Figure 1 Shows the contour of the housing assembly 1 of the present invention, which includes an instrument housing 2 and a head 3. The instrument housing 2 has a front surface 4 and a flat end face 6, which is arranged perpendicular to the front surface 4 and is connected to the straight upper edge 5 of the front surface. The front surface 4 has a maximum width Bmax measured parallel to the straight upper edge 5. The front surface 4 also has a maximum height Hmax measured perpendicular to the straight upper edge 5. The outer contour of the front surface 4 includes a plurality of curves having at least two different curve radii 7, 7', 7".

[0050] Figure 2Schematic side view of the housing assembly of the present invention. The maximum thickness Dmax of the instrument housing can be seen, which is measured perpendicular to the front side 4. The instrument housing 2 also has a back side 4', which can be designed to be exactly equal to the front side 4.

[0051] Figure 3 Schematically shows the measurement of the radius of curvature 7'. The corresponding arc segment is shown as a dashed line. A circle with the corresponding arc segment overlaps it, and the circle radius 81 corresponds to the radius of curvature 7'.

[0052] Figure 4 Schematically shows the determination of the filling coefficient, which consists of the area ratio of the front side 4 to the rectangle 9 defined by Bmax and Hmax. The shaded area corresponds to the part of the rectangle area not filled by the area of the front side 4.

[0053] Figure 5 Schematically shows the determination of the filling coefficient, which consists of the area ratio of the front side 4 to the ellipse 10, which has Bmax and Hmax as the major axis and minor axis. The area of the front side 4 not covered by the shaded area corresponds to the area part exceeding the area of the ellipse.

Claims

1. A housing assembly (1) for an IMD, comprising an instrument housing (2), the instrument housing having: - A front face (4), - A flat end face (6) which is arranged perpendicular to the front face (4) and abuts against the straight upper edge (5) of the front face, - Among them, The front face (4) has a maximum width (Bmax) measured parallel to the straight upper edge (5) and a maximum height (Hmax) measured perpendicular to the straight upper edge (5), Characterized in that the ratio R of the maximum width (Bmax) to the maximum height (Hmax), i.e., Bmax / Hmax, has a value between 1.05 and 1.35, wherein the ratio of the area of the front face (4) to the area of the rectangle (9) defined by the maximum width (Bmax) and the maximum height (Hmax), i.e., area(front face) / area(rectangle), is at least 0.6, or at least 0.7, or at least 0.75, or at least 0.8, or at least 0.85, or at least 0.9, or at least 0.95, so that the instrument housing is circular-like or oval-like, Wherein the IMD is a cardiac pacemaker, an implantable cardioverter defibrillator or a CRT device.

2. The housing assembly (1) according to claim 1, wherein, The value of R is between 1.1 and 1.30, or between 1.15 and 1.275, or between 1.2 and 1.275, or is 1.

25.

3. The housing assembly (1) according to claim 1, wherein, The maximum width (Bmax) has a value between 40 mm and 70 mm, or between 50 mm and 65 mm, or between 55 mm and 65 mm, or is 60 mm.

4. The housing assembly (1) according to claim 1, wherein, The maximum height (Hmax) has a value between 40 mm and 70 mm, or between 40 mm and 60 mm, or between 45 mm and 55 mm, or between 45 mm and 52 mm, or is 48 mm.

5. The housing assembly (1) according to any one of the preceding claims 1-4, wherein, The instrument housing (2) has a maximum thickness (Dmax), wherein the thickness is measured perpendicular to the plane of the front face, and the maximum thickness has a value between 9 mm and 15 mm, or between 9 mm and 12 mm, or between 10 mm and 11 mm, or is 10 mm.

6. The housing assembly (1) according to any one of the preceding claims 1-4, wherein, The instrument housing (2) has a back face (4'), the back face being exactly equal and oppositely arranged to the front face (4), and the flat end face (6) abuts against the straight upper edge of the back face (4').

7. The housing assembly (1) according to one of the preceding claims 1-4, wherein, The outer contour of the front face (4) has a plurality of curves including at least two different curve radii (7, 7', 7"), wherein the maximum curve radius (8) does not exceed 12 cm or 11 cm or 10 cm or 9.5 cm.

8. The housing assembly (1) according to any one of the preceding claims 1-4, wherein, The ratio of the area of the front face (4) to the area of the ellipse (10) defined by the maximum width (Bmax) and the maximum height (Hmax), i.e., area(front face) / area(ellipse), is at most 1.5, or at most 1.4, or at most 1.3, or at most 1.2, or at most 1.15, or at most 1.

1.

9. The housing assembly (1) according to claim 6, wherein, The instrument housing (2) includes two housing covers, wherein the first housing cover has the front side (4) and the second housing cover has the back side (4'), and wherein the first and second housing covers are symmetrically formed.

10. The housing assembly (1) according to any one of the preceding claims 1-4, wherein, The instrument housing (2) has rounded edges.

11. The housing assembly (1) according to any one of the preceding claims 1-4 further comprises a head (3), wherein, The head (3) is connected to the instrument housing (2) at the flat end face (6).

Images