CARDIAC MONITOR

• US 3,832,994 A
• Filed: 04/21/1972
• Issued: 09/03/1974
• Est. Priority Date: 04/21/1972
• Status: Expired due to Term

• Current Assignee: Haim I. Bicher, Lon A. Sorenson
• Original Assignee: Haim I. Bicher, Lon A. Sorenson
• Inventors: Bicher, Haim I., Sorenson, Lon A.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/246,124
• Time in Patent Office: 865 Days
• Field of Search: 128/2.5R,2.5T,2.6A,2.6B,2.6E,2.6F,2.6G,2.6V,2.1A
• US Class Current: 600/515
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives
• CPC Class Codes: Y10S 128/903 Radio telemetry

Abstract

A cardiac monitor provides a real time analysis of critical cardiac functions. The cardiac monitor includes a first unit which, via a plurality of electrodes, is utilized to sense atrial and ventricular activity of a patient'"'"''"'"'s heart to provide an analog EKG signal which includes the P,Q,R,S and T components of the analog EKG signal. The analog EKG signal is converted to a voltage controlled frequency modulated signal which is transmitted, via an FM transmitter, to a remote second unit which is advantageously carried by the patient. In the second unit, the analog EKG signal is detected in an FM detector and processed in an analog to digital converter which provides digital pulses related to the P,Q,R,S and T components of the analog EKG signal. The digital pulses are processed in various logic processing circuits which develop signals containing cardiac information. The cardiac information signals are analyzed to provide various alarm signals responsive to the sensing of cardiac abnormalities. Among the abnormalities which are sensed are atrial and ventricular bradycardias, atrial and ventricular tachycardias, long ventricular contractions, long atrial to ventrical conductions, premature ventricular contractions and junctional rhythms.

Claims

1. A cardiac monitor for analyzing cardiac rhythms, comprising:

a. means for providing an analog signal responsive to said cardiac rhythms including the P, Q, R, S and T components of said cardiac rhythms;

b. analog to digital converter means for converting said analog signal into a series of pulses including P, Q, R, S and T pulses corresponding to the P, Q, R, S and T components of said cardiac rhythms;

c. means for generating a series of clock pulses;

d. means for generating delayed R pulses occurring at a predetermined time interval subsequent to the occurrence of said R pulse;

e. counter means responsive to said R pulses and said clock pulses for producing a count signal indicative of the number of clock pulses occurring between successive R pulses;

f. decoding means coupled to receive said count signal and said clock pulses for producing a first potential level signal when said count is less than said predetermined number; and

g. means responsive to said first potential level signal and said delayed R pulses for producing an output signal indicative of an abnormally short time interval between successive R pulses.

2. The cardiac monitor for analyzing cardiac rhythms, comprising:

a. means for providing an analog signal responsive to said cardiac rhythms including the P, Q, R, S and T components of said cardiac rhythms;

b. analog to digital converter means for converting said analog signal into a series of pulses including P, Q, R, S and T pulses corresponding to the P, Q, R, S and T components of said cardiac rhythms;

c. means for generating a series of clock pulses;

d. first counter means responsive to said R pulses and said clock pulses for producing a first count signal indicative of the number of clock pulses occurring between successive R pulses;

e. decode means responsive to said count signal and said clock pulses for producing decode signals when the number of clock pulses exceeds a first predetermined number but is less than a second prEdetermined number;

f. second counter means responsive to a first decode signal and said R pulses for establishing a heartbeat depended interval by producing a second count signal indicative of the number of successive R pulses occurring after occurrence of the first decode signal;

g. second decode means responsive to said second count signal for generating an interval signal at the end of said heartbeat dependent interval when a predetermined number of successive R pulses have been counted;

h. tally means responsive to said decode signals and said interval signal for producing a tally signal indicative of the number of decode signals occurring during said hearbeat dependent interval; and

i. third decode means responsive to said tally signal for producing an output signal indicative of an abnormally high number of decode signals during said heartbeat dependent interval.

3. A cardiac monitor for analyzing cardiac rhythms, comprising:

a. means for providing an analog signal responsive to said cardiac rhythms including the P, Q, R, S and T components of said cardiac rhythms;

b. analog to digital converter means for converting said analog signal into a series of pulses including P, Q, R, S and T pulses corresponding to the P, Q, R, S and T components of said cardiac rhythms;

c. means for generating a series of clock pulses;

d. means for generating delayed R pulses occurring at a predetermined time interval subsequent to the occurrence of said R pulse;

e. means for generating TB pulses indicative of the interval between an R pulse and a successive P pulse;

f. gate means responsive to said delayed R pulses and said TB pulses for generating signals indicative of ectopic R pulses;

g. counter means responsive to said ectopic R pulses and said clock pulses for generating a count signal indicative of the number of clock pulses occurring after the occurrence of a first ectopic R pulse;

h. first decode means responsive to said count signal for generating a first decode signal when said count signal indicates that said counter means has counted a predetermined number of clock pulses;

i. tally means responsive to said ectopic R pulses and said first decode signal for generating a tally signal indicative of the number of ectopic R pulses which occur between the first ectopic R pulse and said first decode signal; and

j. second decode means responsive to said tally signal for generating a second decode signal indicative of an abnormally high number of ectopic R pulses occurring between said first ectopic R pulse and said tally signal.

4. A cardiac monitor for analyzing cardiac rhythms, comprising:

a. means for providing an analog, signal responsive to said cardiac rhythms including the P, Q, R, S and T components of said cardiac rhythms;

b. analog to digital converter means for converting said analog signal into a series of pulses including P, Q, R, S and T pulses corresponding to the P, Q, R, S and T components of said cardiac rhythms;

c. means for generating delayed R pulses occurring at a predetermined time interval subsequent to the occurrence of said R pulse;

d. means for generating P-Rd pulses indicative of the interval between the P pulse and the delayed R pulse;

e. means for generating TB pulses indicative of the interval between the R pulse and the next succeeding P pulse;

f. gate means responsive to R pulses, TB pulses and P-Rd pulses for producing a missed P pulse when P pulses are missing from said cardiac rhythms signal;

g. latch means responsive to said missed P pulse for generating a first latch signal when a first missed P signal occurs;

h. tally means responsive to said first latch signal and said missed P pulses for providing a tally signal indicative of the number of missed P signals;

i. counter means responsive to said first latch signal and said R pulses for providing a count signal when said counter means counts a predetermined number of R pulses, said count signal being coupled to said latch means to produce a second latch signal, said tally means being responsive to said second latch signal to terminate counting of said missed P signals; and

j. decode means responsive to said tally signal for producing an output signal indicative of an abnormally high number of missed P signals.

5. A cardiac monitor for analyzing cardiac rhythms, comprising:

a. means for providing an analog signal responsive to said cardiac rhythms including the P, Q, R, S and T components of said cardiac rhythms;

b. analog to digital converter means for converting said analog signal into a series of pulses including P, Q, R, S and T pulses corresponding to the P, Q, R, S and T components of said cardiac rhythms;

c. means for generating delayed P pulses occurring at a predetermined time interval after said P pulses;

d. means for generating first delayed R pulses occurring at a first predetermined time after the occurrence of said R pulses;

e. means for generating second delayed R pulses occurring at a predetermined time after the occurrence of said first delayed R pulses;

f. means for generating P-Rdd pulses indicative of the time interval between said P pulse and said second delayed R pulses;

g. means for generating a series of clock pulses;

h. first counter means responsive to said P-Rdd pulse and said clock pulses for producing a first count signal indicative of the number of clock pulses occurring during the duration of said P-Rdd pulse signal;

i. decode means responsive to said count signal for generating a decode signal when the number of clock pulses counted by said counter means is less than a predetermined number; and

j. means responsive to said first delayed R pulses;

said delayed P pulses and said decode signal for producing short P-R signals indicative of an abnormally short time interval between said P pulse and said R pulse.

6. The cardiac monitor of claim 5 further including:

a. second counter means responsive to said short P-R signals and said R pulses for providing a second count signal when said second counter means counts a predetermined number of R pulses;

b. tally means responsive to said second count signal and said short P-R signal for providing a tally signal indicative of the number of short P-R signals which occur between the first short P-R signal and said second count signal; and

c. second decode means responsive to said tally signal and said short P-R signals for generating an output signal indicative of an abnormally high number of short P-R signals.

7. A cardiac monitor for analyzing cardiac rhythms, comprising:

a. means for providing an analog signal to said cardiac rhythms including the P, Q, R, S and T components of said cardiac rhythms;

b. analog to digital converter means for converting said analog signal into a series of pulses including P, Q, R, S and T pulses corresponding to the P, Q, R, S and T components of said cardiac rhythms;

c. means for generating a series of clock pulses;

d. means for generating Q and S pulses which are the inverse of said Q pulses and said S pulses;

e. means for generating TB pulses representative of the interval between an R pulse and the next succeeding P pulse;

f. means responsive to said Q, S and TB pulses for providing a signal indicative of the trailing edge of said S pulses;

g. means for generating TB pulses which are the inverse of said TB pulses;

h. means responsive to said Q, S and TB pulses for producing a signal indicative of the leading edge of said Q pulses;

i. means responsive to the signals indicative of the leading edge of said Q pulses and the trailing edge of said S pulses for generating QRS pulses indicative of the interval between the Q and S pulse and QRS pulses which are the inverse of said QRS pulses;

j. counter means responsive to said QRS pulses and said clock pulses for providing a count signal indicative of the number of clock pulses counted during the duration of said QRS pulses; and

k. decode means responsive to said count signal and said QRS pulses for producing an output signal when there is an abnormally long duration between a Q pulse and an S pulse.

8. A cardiac monitor for providing a real time analysis of cardiac rhythms, comprising:

a. a sensor including means for providing an analog EKG signal responsive to said cardiac rhythms and normally including P, Q, R, S and T components;

b. a processor remote from said sensor for analyzing said analog EKG signal, said processor including;

i. analog to digital converter means for providing a series of pulse signals including P, Q, R, S and T pulses corresponding to the P, Q, R, S and T components of said cardiac rhythms;

ii. means for providing a series of clock pulses;

iii. first digital means responsive to said clock pulses and said P, Q, R, S and T pulse signals for providing an ectopic pulse signal corresponding to an ectopic R component of said analog EKG signal occurring during an interval between the regular occurrence of the R components of said analog EKG signal;

iv. second digital means responsive to said ectopic pulse signal for producing an alarm signal indicative of the occurrence of said ectopic pulse signal; and

c. means for coupling said analog EKG signal from said sensor to said remote processor.

9. The cardiac monitor of claim 8 wherein said first digital means further includes tally means responsive to said ectopic pulse signals for counting said ectopic pulse signals and providing a first signal when said tally means has counted a predetermined number of ectopic pulse signals, said second digital digital means being responsive to said first signal for producing said signal when said tally means has counted a predetermined of ectopic pulse signals.

10. The cardiac monitor of claim 9 wherein said tally means further includes tally interval means for establishing a tally interval, said tally interval means being responsive to a first ectopic pulse signal for starting said tally interval, said tally interval extending for a predetermined time interval after the occurrence of said first ectopic pulse, said first signal being provided when said tally means counts a predetermined number of ectopic pulse signals during said tally interval.