Digital gain control for the reception of telemetry signals from implanted medical devices

• US 4,531,523 A
• Filed: 10/04/1984
• Issued: 07/30/1985
• Est. Priority Date: 10/04/1984
• Status: Expired due to Fees

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Anderson, Katherine H.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US06/657,446
• Time in Patent Office: 299 Days
• Field of Search: 128/419 PG, 128/419 PT, 128/696,903
• US Class Current: 607/32
• CPC Class Codes: A61N 1/37252 Details of algorithms or data aspects of communication system, e.g. handshaking, transmitting specific data or segmenting data
• CPC Class Codes: A61N 1/3727 characterised by the modulation technique
• CPC Class Codes: Y10S 128/903 Radio telemetry

Abstract

A gain control system for verifying the programming of an implanted medical device is provided for an external programming unit which receives transmitted signals from the implanted unit and verifies if these signals represent valid "1" and "0" data bits. If the signals of an encoded message unit are valid signals then processing continues. If some of the signals are invalid due to noise interference, the gain of the receiver of the programming unit is decremented in steps as long as the error rate exceeds a predetermined number of errors per unit time.

Claims

1. A gain control system for verifying the programming of an implanted medical device wherein the programmed implanted device transmits telemetry confirmation signals to a programming means with a variable-gain receiving means after the programming of said implanted device, wherein said signals are encoded binary signals that comprise a plurality of bits;

comprising;

means for establishing the response of said receiving means so that said response may be altered to eliminate noise when the signal level exceeds the noise level;

means for verifying that the encoded signals sent from said implanted device represent valid 1 and 0 data bits;

means for processing further information from said implanted device only if all of the bits of said encoded signals are verified as valid 1 and 0 data bits;

means for establishing a sampling period and for determining the number of error bits in said signals which are caused by noise and which do not correspond to correct data bits of said encoded signals during said period of time; and

means for varying said response by a predetermined amount when the number of said error bits exceed a predetermined amount during one of said periods of time so that said response relative to a threshold level is altered.

2. A gain control system as claimed in claim 1 wherein said response of said receiving means is a gain response and the gain of said receiving means is decremented so that said noise level is eventually reduced below said threshold level.