Body tissue depolarization evaluation system

• US 4,411,271 A
• Filed: 02/10/1982
• Issued: 10/25/1983
• Est. Priority Date: 02/10/1982
• Status: Expired due to Fees

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Markowitz, H. Toby
• Primary Examiner(s): Kamm, Wm. E.
• Assistant Examiner(s): Shein, Mitchell J.
• Application Number:
  US06/347,522
• Time in Patent Office: 622 Days
• Field of Search: 128/702-704, 128/706, 128/708, 128/696
• US Class Current: 600/516
• CPC Class Codes: A61N 1/365 controlled by a physiological parameter, e.g. heart potential evoked response A61N1/371
• CPC Class Codes: A61N 1/371 Capture, i.e. successful stimulation

Abstract

An evaluation system for use in conjunction with a body implantable body stimulator, the body stimulator including a stimulation delivering and depolarization sensing lead system. An input connects a digitizer to the lead system, the digitizer digitizing depolarization signals sensed by the lead system. A computing system identifies excursions in the digitized depolarization signals and evaluates identified excursions in accordance with preselected merit criteria. An output gives an indication of at least that excursion having the highest merit that satisfies said merit criteria.

Claims

1. An evaluation system for use in conjunction with a body implantable body stimulator, the body stimulator including a stimulaton delivering and depolarization sensing lead system, said evaluation system comprising:

input means adapted for connection to said lead system;

means for digitizing depolarization signals sensed by said lead system;

computing means including means for identifying excursions in the digitized depolarization signals and means for evaluating identified excursions in accordance with a preselected plurality of merit criteria; and

output means for giving an indication of at least that excursion having the highest merit that satisfies said merit criteria.

2. The system of claim 1 wherein said output means gives an indication of the first evaluated excursion satisfying said merit criteria and excursions evaluated subsequent to said first indicated excursion having greater merit than the last indicated excursion.

3. The system of claim 2 wherein said output means comprises means for displaying peak-to-peak amplitude of indicated excursions.

4. The system of claim 3 wherein said displaying means comprises digital displaying means.

5. The system of claim 1 wherein said merit criteria include excursion slew rate and excursion peak-to-peak amplitude.

6. The system of claim 5 wherein said merit criteria further include excursion duration.

7. The system of claim 6 wherein said output means gives an indication of the first evaluated excursion satisfying said merit criteria and excursions evaluated subsequent to said first indicated excursion having greater merit than the last indicated excursion.

8. The system of claim 6 wherein said merit criteria further include, for excursions subsequent to a first indicated excursion, occurrence within a preselected interval after said first indicated excursion and the relative peak-to-peak amplitude relative to the last indicated excursion within said preselected interval.

9. The system of claim 8 wherein said output means comprises means for displaying peak-to-peak amplitude of indicated excursions.

10. The system of claim 9 wherein said displaying means comprises digital displaying means.

11. The system of claim 10 wherein said excursion identifying means identifies excursions having a negative slope.

12. The system of claim 11 wherein said merit criteria comprise an excursion slew rate greater than 0.1 V/sec., an excursion peak-to-peak amplitude greater than 1.0 mV, and an excursion duration greater than 3 msec. but no greater than 30 msec.

13. The system of claim 12 wherein said preselected interval is 200 msec.

14. The system of claim 13 wherein said output means gives an indication of the first evaluted excursion satisfying said merit criteria and excursions evaluated subsequent to said first indicated excursion during said preselected interval that satisfy said merit criteria and have a peak-to-peak amplitude greater than the last indicated excursion during said preselected interval.

15. The system of claim 1 wherein said excursion identifying means identifies excursions having a negative slope.