Heartbeat data acquisition conversion and display system

• US 4,125,111 A
• Filed: 07/12/1976
• Issued: 11/14/1978
• Est. Priority Date: 10/31/1975
• Status: Expired due to Term

• Current Assignee: United States Surgical Corporation (Medtronic Plc)
• Original Assignee: United States Surgical Corporation (Medtronic Plc)
• Inventors: Dykstra, Jerald P., Quisenberry, Tony M., Boger, Allen D. Jr., Hunt, Glenn E., Hudspeth, Emmett L., Neathery, John L. Jr., Sims, William B. Jr., Richardson, Philip C.
• Primary Examiner(s): Howell, Kyle L.
• Application Number:
  US05/704,655
• Time in Patent Office: 855 Days
• Field of Search: 128/2.05 P, 128/2.05 T, 128/2.05 R, 128/2.06 F
• US Class Current: 600/502
• CPC Class Codes: A61B 2560/0456 Apparatus provided with a docking unit
• CPC Class Codes: A61B 5/02055 Simultaneously evaluating both cardiovascular condition and temperature
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: G01R 13/00 Arrangements for displaying electric variables or waveforms

Abstract

Heartbeat data is measured and converted into a series of electrical output pulses, the frequency of which is related to the heartbeat pulse rate. The output pulses trigger "on" and "off" a timing device, and the average time of a heartbeat cycle is then converted into a heartbeat pulse rate and displayed. The timing device includes a means for delaying a first specified number of output pulses before beginning the sampling period and registering a count of clock pulses which represents the time period of a second specified number of the output pulses occurring subsequently to the first specified number of output pulses.

Claims

1. A heartbeat data acquisition, conversion and display system comprising:

a pulse rate sensor having a resistance varying cyclically with heartbeat pulse rate;

first means connected to the pulse rate sensor to generate a series of electrical output pulses having a repetition rate related to the cyclic change in the resistance of the pulse rate sensor;

means for generating a train of clock pulses,

a counter receiving the clock pulses, and triggered into an "on" state by a first specified number of output pulses of said first means and triggered into an "off" state by a second specified number of subsequent output pulses of said first means and where a total count registered represents the time period of the second specified number of output pulses representing the cyclic changes in the resistance of the pulse rate sensor;

a divider receiving the total count of the counter wherein the numerator of the divider is a scaling constant and the denominator of the divider is the total count of the counter and where the output of the divider represents the average pulse rate in heartbeat pulses per minute; and

display means connected to said divider for displaying the pulse rate.

2. A heartbeat data acquisition, conversion and display system as set forth in claim 1 wherein said counter comprises:

a first register connected to the first means for generating an "on" signal upon receiving the first specified number of output pulses from the first means and for generating an "off" signal upon receiving the second specified number of subsequent output pulses from the first means; and

a second register receiving the clock pulses, and triggered into an "on" state and an "off" state by the first register, and where the total count registered represents the time period of the second specified number of output pulses representing the cyclic changes in the resistance of the pulse rate sensor.

3. A heartbeat data acquisition, conversion and display system as set forth in claim 1 wherein the first means comprises:

voltage generating means connected to the pulse rate sensor to generate a voltage varying with the cyclic variation in the resistance thereof;

an amplifier connected to the voltage generating means to amplify the varying voltage thereof;

a Schmitt trigger circuit connected to the output of said amplifier and responsive to the amplified varying voltage thereof to generate a series of output pulses having a repetition rate related to the cyclic change in the resistance of the pulse rate sensor; and

a one-shot multivibrator connected to the Schmitt trigger circuit responsive to the output pulses thereof to generate a series of output pulses of uniform duration at a repetition rate related to the cyclic change in the resistance of the pulse rate sensor.