Magnetless implantable stimulator and external transmitter and implant tools for aligning same

• US 6,141,591 A
• Filed: 05/10/1999
• Issued: 10/31/2000
• Est. Priority Date: 03/06/1996
• Status: Expired due to Fees

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Advanced Bionics Corporation (Sonova Holding AG)
• Inventors: Neuburger, Jurgen, Weber, Benno P., Lenarz, Thomas
• Primary Examiner(s): LAYNO, CARL HERNANDZ
• Application Number:
  US09/142,293
• Time in Patent Office: 540 Days
• Field of Search: 607/55-57, 607/137
• US Class Current: 607/57
• CPC Class Codes: A61N 1/36038 Cochlear stimulation
• CPC Class Codes: A61N 1/37229 Shape or location of the implanted or external antenna
• CPC Class Codes: A61N 1/37518 Anchoring of the implants, e.g. fixation
• CPC Class Codes: A61N 1/3787 from an external energy source

Abstract

An implantable receiver (12) is powered and controlled by an external (not-implanted) transmitter (14) when a transmitter coil (22) is properly aligned with a receiver coil (20). No magnets are used in either the transmitter or receiver to achieve and maintain the needed alignment. Rather, a special set of implant tools (50) are used to assure that alignment is achieved and maintained between the implantable receiver (12) and external transmitter (14) when the implant operation is carried out. A preferred embodiment of the invention provides a magnetless implantable cochlear stimulator (ICS) (40) and a corresponding magnetless headpiece (30) worn behind the ear.

Claims

1. A magnetless implantable stimulator system comprising an implantable receiver (12) and an external transmitter (14), each having respective coils (20, 22) which, when aligned to provide inductive coupling therebetween, allow power and data signals to be coupled between the transmitter and receiver, wherein the implantable receiver (12) and external transmitter (14) are both magnetless;

and further comprising alignment means for achieving and maintaining a proper alignment between the implantable receiver and external transmitter, said alignment means comprising a set of alignment tools (50) used to implant the receiver in a known location relative to an external reference point; and

means for positioning (38) the external transmitter at the known location relative to the external reference point.

2. The implantable receiver (14) and external transmitter (12, 30) as set forth in claim 1 wherein the receiver comprises an implantable cochlear stimulator (ICS) (40), and wherein said external reference point comprises an ear of a patient'"'"'s head, and wherein said positioning means comprises means for wearing the external transmitter (30) behind the ear.

3. The implantable receiver and external transmitter as set forth in claim 1 wherein said set of alignment tools comprises:

an external marker template (54) usable to mark a desired implant location on the skin of the patient,

a drilling template (60) usable to screw a plurality of screws into the patient'"'"'s tissue/bone at a prescribed location relative to the marked implant location on the skin of the patient,

a subcutaneous marker template (70) usable to mark a location of a subcutaneous bed wherein a cavity may be formed in which the receiver can be implanted, said subcutaneous marker being keyed to the plurality of screws screwed into the patient'"'"'s bone after incising the patient'"'"'s head, and

a receiver dummy (80) that may be removably inserted into the cavity as it is formed to test the cavity for the proper size and depth, said receiver dummy having a shape and size substantially the same as the implantable receiver.

4. The implantable receiver and external transmitter as set forth in claim 3 wherein the drilling template (60) has a plurality of holes (62) therethrough arranged in a prescribed spaced-apart pattern relative to each other, and wherein said subcutaneously marker template (70) also has a plurality of holes (72) therethrough arranged in a pattern that matches the spaced-apart pattern of the holes of the drilling template, whereby the subcutaneous marker template may be positioned over and aligned with holes made using the drilling template.

5. The implantable receiver and external transmitter as set forth in claim 4 further including a plurality of implantable screws (126), respective ones of which may be screwed into tissue/bone of the patient at the locations defined by the plurality of holes of the drilling template.

6. The implantable receiver and external transmitter as set forth in claim 5 wherein said implantable screws (126) are small screws that are implanted subcutaneously through holes in the skin made using the drilling template (60).

7. The implantable receiver and external transmitter as set forth in claim 6 wherein the subcutaneous marker template (70) includes means for aligning (72) it with with the implanted subcutaneous screws when a layer of the patient'"'"'s tissue/skin is pulled back to expose the implanted subcutaneous screws.

8. A method of implanting an implantable receiver device (12) at a known location relative to an externally-marked location, comprising the steps of:

(a) marking on the skin of a patient the location where the implantable receiver is to be implanted;

(b) aligning a drilling template with the location marked in step (a), said drilling template having a plurality of holes therethrough that mark a prescribed spaced-apart relationship between said plurality of holes;

(c) drilling a plurality of holes through the patient'"'"'s skin to a desired subcutaneous depth using the drilling template of step (b) as a guide so that the plurality of holes maintain the prescribed spaced-apart relationship defined by the plurality of holes of the drilling template;

(d) implanting a plurality of screws into the patient'"'"'s bone/tissue by inserting respective screws into each of the plurality of holes formed in step (c), the screws thus implanted maintaining the prescribed spaced-apart relationship defined by the plurality of holes of the drilling template;

(e) incising an area around the plurality of holes and folding back a layer of tissue/skin so as to expose the plurality of implanted screws;

(f) laying a subcutaneous marker template over the exposed implanted screws, said subcutaneous marker template having a plurality of holes therein arranged in a pattern that matches the prescribed spaced-apart relationship defined by the plurality of holes of the drilling template;

(g) marking a desired subcutaneous implant location for the implantable receiver using the subcutaneous marker template aligned with the plurality of screws in step (f);

(h) forming a cavity/bed for the implantable receiver at the location marked in step (g); and

(i) implanting the implantable receiver within the cavity/bed formed in step (h), whereby the implant location is aligned with the implant location initially marked in step (a).

9. The method as set forth in step 8 wherein step (h) includes using a receiver dummy to help measure the size of the cavity/bed as it is being formed, said receiver dummy having a physical size and shape that is substantially the same size and shape as the implantable receiver.