Communication method for implantable medical device

• US 5,728,154 A
• Filed: 02/29/1996
• Issued: 03/17/1998
• Est. Priority Date: 02/29/1996
• Status: Expired due to Fees

• Current Assignee: Penn State Research Foundation
• Original Assignee: 3M Company
• Inventors: Nazarian, Richard A., Hamerly, Michael, Crossett, Stanley J.
• Primary Examiner(s): ISABELLA, DAVID J
• Application Number:
  US08/610,167
• Time in Patent Office: 747 Days
• Field of Search: 128/899, 128/898, 128/904, 128/630, 623/3, 623/2, 623/66, 607/32, 607/30, 607/60, 600/16, 600/17
• US Class Current: 128/899
• CPC Class Codes: A61F 2250/0001 Means for transferring electromagnetic energy to implants
• CPC Class Codes: A61M 60/148 in line with a blood vessel using resection or like techniques, e.g. permanent endovascular heart assist devices
• CPC Class Codes: A61M 60/196 replacing the entire heart, e.g. total artificial hearts [TAH]
• CPC Class Codes: A61M 60/446 the axis of both movements being parallel, e.g. roller screw actuators or cylindrical cam transmissions
• CPC Class Codes: A61M 60/538 Regulation using real-time blood pump operational parameter data, e.g. motor current
• CPC Class Codes: A61M 60/592 Communication of patient or blood pump data to distant operators for treatment purposes
• CPC Class Codes: A61M 60/88 Percutaneous cables

Abstract

A medical assembly, such as an artificial heart assembly, adapted to be implanted within a living subject is composed of an implantable data communications interface adapted to receive an encoded data signal from a data communications interface located outside the subject at a position remote from the medical assembly. The encoded data signal is transmitted in a plurality of periodic signal bursts, which are transmitted at a first frequency to represent a first data value and a second frequency to represent of second data value. Each of the bursts comprises a plurality of signal transitions having a third frequency greater than both the first and second frequencies.

Claims

1. A method of communication between a first data communications interface implanted within a subject and a second data communications interface positioned at a remote location outside of said subject, said method comprising the steps of:

(a) transmitting from said second data communications interface an encoded data signal in a plurality of periodic signal bursts, said signal bursts being transmitted at a first frequency to represent a first data value and a second frequency to represent of second data value, said second frequency being different than said first frequency, each of said bursts comprising a plurality of signal transitions having a third frequency, said third frequency being greater than said first frequency and greater than said second frequency;

(b) receiving said encoded data signal from said second communications interface;

(c) generating an envelope signal from said encoded data signal; and

(d) decoding said envelope signal by detecting which portions of said envelope signal have a frequency substantially equal to said first frequency and which portions of said envelope signal have a frequency substantially equal to said second frequency.

2. A method as defined in claim 1 wherein said step (c) comprises the step of (e) filtering said envelope signal to remove relatively high frequency portions of said encoded data signal.

3. A method as defined in claim 1 wherein said step (d) comprises the step of determining the number of transitions of a clock signal which occur between successive transitions of said envelope signal.

4. A method as defined in claim 1 additionally comprising the steps of:

(e) encoding a second encoded data signal; and

(f) transmitting said second encoded data signal to said remote data communications interface.

5. A method as defined in claim 1 additionally comprising the steps of:

(e) encoding a second encoded data signal in a different manner than said encoded data signal transmitted by said second data communications interface during said step (a); and

(f) transmitting said second encoded data signal to said remote data communications interface.

6. A method as defined in claim 5 wherein said step (e) comprises the step of encoding said second encoded data signal from an original data signal having a plurality of signal transitions, each of said transitions of said original data signal being represented by a phase shift in said second encoded data signal.