Manufacturing Method for an Implantable Medical Device

Abstract

A medical device and a manufacturing method for such medical device having an assembly comprising: an elongated solid housing with an outer surface and a maximum outer diameter, at least one electrical contact area at the outer surface of the housing, and a processor encapsulated within the housing,
wherein the method comprises the following steps: providing the assembly and a tube consisting of a plastic and electrically insulating material, wherein an inner diameter of the tube is greater than the maximum outer diameter (108) of the assembly, accommodating the assembly within the tube such that at least one electrical contact area of the assembly is not covered, and applying a shrinking step to the tube such that the shrunken tube is firmly attached to the outer surface of the housing.

The manufacturing method is cheaper and less time consuming than state-of-the-art methods, and also better suitable for automation.

Claims

1. A manufacturing method for a medical device having an assembly comprising an elongated solid housing with an outer surface and a maximum outer diameter, at least one electrical contact area at the outer surface of the housing, and a processor within the housing, wherein the method comprises the following steps: providing the assembly and a tube consisting of an electrically insulating material, wherein an inner diameter of the tube is greater than the maximum outer diameter of the assembly, accommodating the assembly within the tube such that at least one electrical contact area of the assembly is not covered, and applying a shrinking step to the tube such that the shrunken tube is firmly attached to the outer surface of the housing.

2. The method of claim 1, wherein the material of the tube comprises a polymer material.

3. The method of claim 1, wherein the shrinking step comprises a thermal treatment and/or infrared and/or UV treatment.

4. The method of claim 1, wherein the shrinking step is provided such that the shrunken tube hermetically seals the outer surface of the housing.

5. The method of claim 1, wherein initially the inner diameter of the tube is smaller than the maximum outer diameter of the assembly, wherein the method comprises the additional step of swelling applied to the tube such that the inner diameter of the swollen tube greater than the maximum outer diameter of the assembly prior the accommodation of the assembly within the tube, and wherein the shrinking step comprises a drying treatment.

6. The method of claim 5, wherein the swelling is provided by a chemical treatment with a fluid comprising an alkane, for example heptane.

7. The method of claim 1, wherein the tube comprises an adhesive at its inner surface prior the accommodation of the assembly within the tube, wherein the adhesive is activated during or after the shrinking step.

8. A medical device comprising: an elongated solid housing with an outer surface, at least one electrical contact area at the outer surface of the housing, and a processor encapsulated within the housing, and a plastic and electrically insulating layer firmly attached to the outer surface of the housing, wherein the layer is obtained by shrinking a tube to the outer surface of the housing, wherein the insulating layer does not cover the at least one electrical contact area.

9. The medical device of claim 8, wherein the housing has a circular cross-section.

10. The medical device of claim 8, wherein the housing has a bag-like shape and/or the housing has a relation of length to width which is greater than 2.

11. The medical device of claim 8, wherein the device comprises an energy supply unit encapsulated within the housing, wherein the energy supply unit is in electrical contact with the processor, wherein the energy supply unit is, for example, a battery, an accumulator or a generator.

12. The medical device of claim 8, wherein the device comprises an intermediate layer located between the outer surface of the housing and the electrically insulating layer, wherein the intermediate layer comprises an adhesive.

13. The medical device of claim 8, wherein the medical device is one of an implantable loop recorder, an implantable cardiac pacemaker, an implantable leadless pacemaker, an implantable leadless pressure sensor, an implantable cardioverter-defibrillator or a subcutaneous implantable cardioverter-defibrillator.

14. The medical device of claim 8, wherein the material of the electrically insulating layer comprises at least one material of the group comprising silicone and parylene.

15. The medical device of claim 8, wherein the processor is adapted to receive electrical signals, wherein the signals are preferably measured at least one contact area, and/or to process electrical signals and/or to send electrical signals.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The specification refers to the accompanying figures showing schematically:

[0037] FIG. 1 a first step of a first embodiment of an inventive manufacturing method with a medical device in a side view, and

[0038] FIG. 2 a tube in a longitudinal section,

[0039] FIG. 3 a second and third step of the first embodiment of the manufacturing method with the medical device in a side view and the tube in a longitudinal section,

[0040] FIG. 4 the result of the third step shown in FIG. 3,

[0041] FIG. 5 an initial tube of a second embodiment of an inventive manufacturing method in a longitudinal section,

[0042] FIG. 6 the tube of FIG. 5 after a manufacturing step of the second embodiment in a longitudinal section, and

[0043] FIG. 7 the medical device of FIG. 1 in a front view.

DETAILED DESCRIPTION

[0044] A medical device 100 is shown in FIG. 1, for example, an implantable loop recorder or an implantable leadless pacer, which comprises a solid housing 101 with a first contact area 109 and a second contact area 110 located at the proximal and the distal end of the housing 101, respectively. The medical device 100 according to FIG. 1 has a length 107 and a width 108, wherein the width 108 forms at the same time the maximum outer diameter of housing 101 and the first diameter of a distal section of the housing 101. Further, the housing 101 comprises a second diameter 106 at a proximal section of the housing 101. The housing 101 further comprises an intermediate section between the proximal section with the smaller diameter 106 and the distal section with the greater diameter (width 108).

[0045] Additionally, the medical device 100 comprises an encapsulated processer 104, a battery (not shown) forming and being part of an electronic circuit (not shown) provided on a circuit board (e.g., printed circuit board, PCB). The electronic circuit is electrically connected to the first and second contact area 109, 110, which are in contact to the human body environment if the medical device 100 is implanted in a human body. Additionally, the processor 104 may comprise a receiver and/or a sender (both not shown).

[0046] FIG. 2 shows a tube 200 for the electrically insulating layer with a first aperture 201 and a second aperture 203. The tube 200 has an inner diameter 204, which is relevant for the accommodation of the medical device 100 and shrinking described below.

[0047] After providing the medical device 100 and the tube 200, the medical device 100 is placed within the tube 200 which is possible since the inner diameter 204 of the tube 200 is greater than the maximum outer diameter (width 108) of the medical device 100. The medical device 100 is introduced into the tube 200 through the first aperture 201 or the second aperture 203 of the tube and accommodated such that the first and second contact area 109, 110 is not covered.

[0048] Before accommodating the medical device 100 within tube 200, an adhesive may additionally be applied at the inner surface of the tube 200 or on the surface of the device 100 thereby reducing the friction at the interface of the device 100 and tube 200.

[0049] After correct accommodation of the medical device 100 within the tube 200, a thermal treatment is applied, e.g., with the following parameters 80° C. for 30 seconds. The thermal treatment is symbolized by arrows 301 in FIG. 3 and leads to shrinking of the tube 200 such that it is firmly attached to the outer surface of the housing 101 at the end of this process step. FIG. 4 depicts the result of the thermal treatment showing an electrically insulating layer 400 formed by the shrunken tube 200 at the outer surface of the housing 101 of the medical device 100, wherein the electrically insulating layer 400 does not cover the first and second contact area 109, 110.

[0050] In an alternative embodiment, as an initial element a tube 600 may be used having an initial inner diameter 604 which is smaller than the maximum outer diameter (width 108) of the medical device 100. Such tube 600 is shown in FIG. 5. The tube 600 is swollen by immersion within heptane (see symbol 500) thereby increasing the dimensions of the tube 600 resulting in the tube 200′ with an increased inner diameter 204′ as shown in FIG. 6. The swollen tube 200′ is used with the manufacturing method shown in FIGS. 1 to 4 and described above, wherein the thermal treatment may be replaced or supplemented by a drying treatment in order to shrink the swollen tube 200′. In the drying treatment, the following process parameters may be applied 35° C.

[0051] FIG. 7 depicts a front view of the medical device shown in FIG. 1. The non-circular (oval) cross section of the proximal section of the housing 101 has second diameter 111 and the oval cross section of the distal section of the housing 101 has second diameter 112, as well. The medical devices implantable loop recorder, implantable leadless pacer, implantable leadless pressure sensor, (subcutaneous) Implantable Cardiac Defibrillator ((s)ICD) have different shapes and dimensions resulting in different geometric requirements for the tube 200 to be shrunken at the outer surface of housing 101 for firm attachment.

[0052] As indicated above, the inventive manufacturing method creates, and the inventive medical device comprises, a partial electrical insulation layer 400 which may easily be adapted in an automated process and to different shapes of the medical device. The insulation layer may enhance the biocompatibility of the outer surface of the medical device.

[0053] It will be apparent to those skilled in the art that numerous modifications and variations of the described examples and embodiments are possible in light of the above teachings of the disclosure. The disclosed examples and embodiments are presented for purposes of illustration only. Other alternate embodiments may include some or all of the features disclosed herein. Therefore, it is the intent to cover all such modifications and alternate embodiments as may come within the true scope of this invention, which is to be given the full breadth thereof. Additionally, the disclosure of a range of values is a disclosure of every numerical value within that range, including the end points.

REFERENCE NUMBERS

[0054] 100 medical device [0055] 101 housing [0056] 104 processor [0057] 106 diameter [0058] 107 length [0059] 108 width, maximum outer diameter [0060] 109 first contact area [0061] 110 second contact area [0062] 111, 112 second diameter [0063] 200, 200′ tube [0064] 201, 201′ first aperture [0065] 203, 203′ second aperture [0066] 204, 204′ inner diameter [0067] 301 arrows [0068] 400 insulating layer [0069] 500 heptane [0070] 600 initial tube [0071] 601 first aperture [0072] 603 second aperture [0073] 604 inner diameter