Telemetry system employing DC balanced encoding

• US 7,689,176 B2
• Filed: 03/07/2005
• Issued: 03/30/2010
• Est. Priority Date: 03/07/2005
• Status: Active Grant

• Current Assignee: Medos International Sarl (Johnson & Johnson)
• Original Assignee: Codman Neuro Sciences Sarl
• Inventors: Crivelli, Rocco
• Primary Examiner(s): Tran; Pablo N
• Application Number:
  US11/073,444
• Publication Number:
  US 20060199560A1
• Time in Patent Office: 1,849 Days
• Field of Search: 455/100, 455/91, 455/95, 455/404.1, 455/66.1, 455/67.11, 455/90.1, 455/130, 455/215, 455/293, 455/311, 455/334, 455/336, 455/341, 340/870.1, 340/870.07, 340/870.16, 340/539.1, 340/572.4, 340/572.8, 340/572.12, 600300-301, 600/309, 600/323, 600/331, 600/384, 600/492
• US Class Current: 455/100
• CPC Class Codes: A61N 1/3727 characterised by the modulation technique
• CPC Class Codes: H04L 25/4904 using self-synchronising codes, e.g. split-phase codes

Abstract

A telemetry system including a first device having a processor that employs a DC balanced encoding scheme to generate a DC balanced encoded data signal, a modulator for modulating an RF carrier wave by the DC balanced encoded data signal and generating a DC balanced encoded RF modulated data signal including DC balanced RF energy. The DC balanced encoded RF modulated data signal transmitted by the first device is received by a second device. Since the RF energy received is DC balanced, drift in baseline voltage is eliminated irrespective of data transmission thereby improving the robustness of recovery of data by the second device. The second device may include a converter for converting the DC balanced RF energy extracted from the received DC balanced encoded RF modulated data signal to a substantially constant average induced voltage, irrespective of data being transmitted, for powering at least one component of the second device.

Claims

1. A telemetry system comprising:

a first device comprising;

a processor that employs a DC balanced encoding scheme to generate a DC balanced encoded data signal;

a carrier generator for generating an RF carrier wave;

a modulator for modulating the RF carrier wave by the DC balanced encoded data signal and generating a DC balanced encoded RF modulated data signal including DC balanced RF energy; and

a transmitter for wirelessly transmitting the DC balanced encoded RF modulated data signal.

2. The system in accordance with claim 1, wherein the DC balanced encoding scheme is Manchester encoding.

3. The system in accordance with claim 1, wherein the modulator comprises:

a mixer coupled to the processor for modulating the RF carrier wave by the DC balanced encoded data signal; and

an amplifier for amplifying the output of the mixer and producing the DC balanced encoded RF modulated data signal.

4. The system in accordance with claim 1, wherein the modulator comprises:

an amplifier for amplifying the DC balanced encoded data signal and producing an amplified DC balanced encoded data signal; and

a mixer coupled to the amplifier for modulating the RF carrier wave by the amplified DC balanced encoded data signal and producing the DC balanced encoded RF modulated data signal.

5. The system in accordance with claim 1, further comprising a second device for receiving the DC balanced encoded RF modulated data signal transmitted by the first device, the DC balanced RF energy eliminating drift in baseline voltage irrespective of data transmission so as to improve recovery of data by the second device.

6. The system in accordance with claim 5, wherein the second device further comprises:

a converter for extracting the DC balanced RF energy from the received DC balanced encoded RF modulated data signal and converting the DC balanced RF energy to a substantially constant average induced voltage, irrespective of data being transmitted, for powering at least one component of the second device.

7. The system in accordance with claim 6, wherein the second device further comprises:

a demodulator for extracting an envelope from the DC balanced encoded RF modulated data signal received by the second device; and

a slicer coupled to the demodulator to receive the extracted envelope and produce a centered, sliced and shaped recovered data.

8. The system in accordance with claim 5, wherein the first device is separated from the second device by a boundary.

9. The system in accordance with claim 8, wherein the first device is an external control device and the second device is an implantable medical device.

10. A telemetry system comprising:

a first device comprising;

a processor that employs a DC balanced encoding scheme to generate a DC balanced encoded data signal;

a carrier generator for generating an RF carrier wave;

a modulator for modulating the RF carrier wave by the DC balanced encoded data signal and generating a DC balanced encoded RF modulated data signal including DC balanced RF energy;

a transmitter for wirelessly transmitting the DC balanced encoded RF modulated data signal; and

a second device receiving the DC balanced encoded RF modulated data signal transmitted by the first device, the DC balanced RF energy eliminating drift in baseline voltage irrespective of data transmission so as to improve recovery of data by the second device.

11. The system in accordance with claim 10, wherein the DC balanced encoding scheme is Manchester encoding.

12. The system in accordance with claim 10, wherein the modulator comprises:

a mixer coupled to the processor for modulating an RF carrier signal with the DC balanced encoded data signal; and

an amplifier for amplifying the output of the mixer and producing the DC balanced encoded RF modulated data signal.

13. The system in accordance with claim 10, wherein the modulator comprises:

an amplifier for amplifying the DC balanced encoded data signal and producing an amplified DC balanced encoded data signal; and

a mixer coupled to the amplifier for modulating the RF carrier wave by the amplified DC balanced encoded data signal and producing the DC balanced encoded RF modulated data signal.

14. The system in accordance with claim 13, wherein the second device comprises a converter for extracting the DC balanced RF energy from the received DC balanced encoded RF modulated data signal and converting the DC balanced RF energy to a substantially constant average induced voltage, irrespective of data being transmitted, for powering at least one component of the second device.

15. The system in accordance with claim 10, wherein the second device comprises:

a demodulator for extracting an envelope from the DC balanced encoded RF modulated data signal received by the second device; and

a slicer coupled to the demodulator to receive the extracted envelope, substantially center the envelope about a reference voltage, slice the envelope substantially symmetric relative to the reference voltage, and reshape the sliced envelope to produced a recovered data stream.

16. The system in accordance with claim 10, wherein the first device is separated from the second device by a boundary.

17. The system in accordance with claim 16, wherein the first device is an external control device and the second device is an implantable medical device.

18. A method for RF communication between a first device and a second device, comprising the steps of:

applying a DC balanced encoding scheme to a data signal to produce a DC balanced encoded data signal;

modulating a generated RF carrier wave by the DC balanced encoded data signal to produce a DC balanced encoded RF modulated data signal including DC balanced RF energy;

wirelessly transmitting the DC balanced encoded RF modulated data signal from the first device; and

receiving at the second device the DC balanced encoded RF modulated data signal, the DC balanced RF energy eliminating drift in baseline voltage irrespective of data transmission so as to improve recovery of data by the second device.

19. The method in accordance with claim 18, further comprising the steps of:

extracting the DC balanced RF energy from the received DC balanced encoded RF modulated data signal;

converting the DC balanced RF energy to a substantially constant average induced voltage irrespective of data being transmitted; and

powering at least one component of the second device using the substantially constant average induced voltage.

20. The method in accordance with claim 18, wherein the first device is an external control device and the second device is an implantable medical device.