Cardiac pacemaker

• US 4,867,162 A
• Filed: 03/17/1987
• Issued: 09/19/1989
• Est. Priority Date: 09/17/1985
• Status: Expired due to Term

• Current Assignee: Biotronik Mess-Und Therapiegeraete GmbH & Company Ingenieurbuero Berlin (Biotronik SE & Company KG)
• Original Assignee: Biotronik Mess-Und Therapiegeraete GmbH & Company Ingenieurbuero Berlin (Biotronik SE & Company KG)
• Inventors: Schaldach, Max
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US07/026,677
• Time in Patent Office: 917 Days
• Field of Search: 128/419 PG
• US Class Current: 607/17
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters

Abstract

A cardiac pacer features plural addressable digital memory elements each containing different pulse parameters for the pacing stimulation, address-selecting digital logic circuitry for choosing the characteristics of the pulses to be generated in response to signals derived from plural physiological sensors detecting different exercise-related body functions to improve control of the heart during various levels of exertion.

Claims

1. A cardiac pacemaker comprising:

first measured value pickup means for detecting a first attribute of a patient'"'"'s body and producing a first output signal representative of said first attribute;

second measured value pickup means for detecting a second attribute of a patient'"'"'s body and producing a second output signal;

circuitry means for varying at least one pacing parameter, in particular the pacing rate, as a function of said first output signal and said second output signal picked up in the patient'"'"'s body and which are associated with physical exertion of the patient'"'"'s body;

means for providing stimulation to a patient'"'"'s body in response to said pacing rate;

calibration means for calibrating an initial output signal detected by said first measured pickup means and for producing a calibrated output signal in response thereto;

compensation means connected to receive output signals from said first measured value pickup means for adjusting said first output signal so as to produce a compensated output signal in response to said first output signal as said calibrated output signal, and during a predetermined period of time said second output signal is substantially identical with said calibrated output signal obtained from said first measured value pickup means, and said compensation means remain substantially unchanged for a following operating period of time.

2. A pacemaker as defined by claim 1, wherein said first attribute detected by and first measured value pickup means is a signal dependent on exertion of the patient'"'"'s body.

3. A pacemaker as defined by claim 1, further comprising memory means for supply and storing data, wherein said circuitry means for varying said at least one pacing parameter is controlled by data supplied to said circuitry means, said data being supplied from memory locations of said memory means, wherein said circuitry means addresses the memory locations in response to an address signal derived by said circuitry means from said first and said second output signals,

the data contained in said memory means being a characteristic data field which is accessed by said circuitry means for controlling the variation of said at least one pacemaker parameter.

4. A pacemaker as defined by claim 3, wherein said memory means stores the data such that the data is accessible based upon input address signals which have an association with each other.

5. A pacemaker as defined by claim 1, wherein said compensation means provides compensation of said first output signal by storing an initial value of said first output signal of said first measured value pickup means for each of a plurality of varying exertion states of the patient in said memory locations, said memory locations being substantially simultaneously addressable by said second output signal of said second value pickup means.

6. A pacemaker as defined by claim 1, further comprising communication means, and wherein said calibration means includes a corresponding external measured value pickup means which is connected during said predetermined period of time with said communication means.

7. A pacemaker as defined by claim 6, wherein said external measured value pickup detects any one of physical exertion, the cardiac output, the heart sound signals, and pressure signals for detecting the stroke volume.

8. A pacemaker as defined by claim 1, wherein said calibration means obtains an operating characteristic curve for use as a control characteristic curve for later operation.

9. A pacemaker as defined by claim 1, wherein said compensation means causes said compensation curve obtained during said predetermined period for calibration to be used as a calibration curve for an ensuing operating mode only when no fault is detected during said predetermined period for calibration.

10. A pacemaker as defined by claim 1, further comprising linking means for selecting any of a plurality of different processing routes and and any one of a plurality of measured value pickups for a measured variable which is dependent on the physical exertion of the patient'"'"'s body, said linking means being initiated to perform selecting in response to a predetermined signal.

11. A pacemaker as defined by claim 1, further comprising a linear, time-dependent transmission element disposed in a signal transmission route for signals associated with the physical exertion of the patient'"'"'s body, said transmission element having an operating characteristic which is in accordance with a simulation of a linear physical system.