HEARTBEAT MONITOR WITH AUDIO AND VISUAL OUTPUTS

• US 3,613,670 A
• Filed: 02/12/1969
• Issued: 10/19/1971
• Est. Priority Date: 02/12/1969
• Status: Expired due to Term

• Current Assignee: Harry J. Edenhofer
• Original Assignee: Harry J. Edenhofer
• Inventors: Edenhofer, Harry J.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US04/798,676
• Time in Patent Office: 979 Days
• Field of Search: 128/2.05,2.06,2.1 331/18,111,112,114
• US Class Current: 600/514
• CPC Class Codes: A61B 5/0245 by using sensing means generating electric signals, i.e. ECG signals

Abstract

A pocket size, self-contained cardiac monitor for on-patient or central station monitoring by visible and/or audible signals related to the beat of a patient'"'"''"'"'s heart, the monitor having the features of: using its own circuitry for calibration; having a time delay to mask out spurious signals; and having circuit means to drive a monitor lamp and speaker with a minimum of power.

Claims

1. For a cardiac monitOr, audible-visible alarm means comprising:

first and second transistors, the emitters of which are adapted to receive a supply voltage transformer mechanism including primary coil means and secondary coil means, the ends of primary coil means being respectively connected to the collectors of said transistors;

a speaker connectable to the secondary coil means of said transformer mechanism;

a circuit including a diode in series with parallel-connected capacitor and neon light, the circuit being connected between the collectors of said transistors;

a first resistor connected to the base of the first transistor and to the collector of said second transistor; and

second resistor connected to the base of the second transistor and to the collector of said first transistor.

2. In a cardiac monitor:

trigger mechanism to receive electrical signals developed as a function of the beat of the patient'"'"''"'"'s heart and to convert the signals into trigger pulses there being a trigger pulse for each beat;

one shot mechanism connected to receive said trigger pulses and having means to develop pulses of first duration each latter pulse being initiated by a trigger pulse;

low delay mechanism connected to receive said one-shot pulses and having means actuated at the termination of each one-shot pulse to develop low delay pulses and the low delay mechanism including means to adjust the duration of each low delay pulse, said duration corresponding to a selected heart beat rate with a low range;

high delay mechanism connected to receive said one-shot pulses and being actuated at the termination of each one shot pulse to develop high delay pulses and the high delay mechanism including means to adjust the duration of each high delay pulse, said duration corresponding to a selected heart beat rate with a high range;

comparing means connected to operate alternatively as follows;

a. to receive said one shot pulses and said low delay pulses and to compare the interval between the end of the low delay pulse and the start of the next one shot pulse and develop an output signal as a function of said interval;

or b. to receive said one shot pulses and said high delay pulses and develop an output signal which is initialed when the start of a one shot pulse occurs before the termination of a high delay pulse. monitor mechanism including audio and/or visible means and having connections with said comparing means to receive its output signal and activate the audible and/or visible means when the heart beat rate is within the low range and when the heart beat rate is within the high range; and

switch means to disconnect the trigger mechanism and the input of one shot mechanism and to connect, alternatively, the output of the low delay mechanism or the output of the high delay mechanism with the input of the one shot mechanism, the switches providing for the use of the one shot, the low delay and the high delay to check the calibration of said low delay and said high delay adjusting means.

3. In a cardiac monitor:

trigger mechanism to receive electrical signals developed as a function of the beat of a patient'"'"''"'"'s heart and to convert the signals into trigger pulses there being a trigger pulse for each beat;

one-shot mechanism connected to receive said trigger pulses and having means to develop pulses of fixed duration, each latter pulse being initiated by a trigger pulse;

low delay mechanism connected to receive said one shot pulses and having means actuated at the termination of each one shot pulse to develop low delay pulses and the low delay mechanism including means to adjust the duration of each low delay pulse, said duration corresponding to a selected heart beat rate within a low range;

high delay mechanism connected to receive said one shot pulses and being actuated at the termination of each one shot pulse to develop high delay pulses and the high delay mechanism including means to adjust the duration of eAch high delay pulse, said duration corresponding to a selected heart beat rate within a high range;

comparing means connected to operate alternatively as follows;

a. to receive said one shot pulses and said low delay pulses and to compare the interval between the end of a low delay pulse and the start of the next one shot pulse and develop an output signal as a function of said interval;

or b. to receive said one shot pulses and said high delay pulses and develop an output signal which is initiated when the start of a one shot pulse occurs before the termination of a high delay pulse. monitor mechanism including audio and/or visible means and having connections with the output of said comparing means to receive its output signal and activate the audible and/or visible means when the heart beat rate is within the low range and when the heart beat rate is within the high range; and

said connections between the comparing means and the monitor mechanism including means operative upon receipt of he initial output signal of the comparing means to prevent the comparing means output signals from reaching the monitor mechanism for a predetermined amount of time whereby to mask out the effects of false trigger signals.