# US 4,377,727 A · Stethoscope having means for measuring pulse frequency

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- Number: US 4,377,727 A
- Document ID: US4377727A
- Status: Granted
- Kind: A
- Application number: 06/220,136
- Filed: 1980-12-24
- Granted: 1983-03-22
- Earliest claimed: 1980-12-24
- Inventors: Joseph C. Schwalbach
- Web page: https://patentgrep.com/patent/US4377727A

## CPC

- A61B 5/024: Measuring pulse rate or heart rate
- A61B 7/02: Stethoscopes
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)

## Abstract

An improved stethoscope having means for measuring the frequency of a series of pulses, such as human heart pulses, is disclosed, in the use of which such pulses are detected simultaneously with detection of a series of timed detectable reference impulses produced by a reference impulse producer having means for adjusting the frequency of the reference impulses produced thereby and also having readout means indicating the frequency of the reference impulses, wherefore upon adjustment of the frequency of the reference impulses as necessary to match that of said pulses, the frequency of said pulses is indicated on the readout means.

## Claims

### Claim 1

In a stethoscope having means for conducting directly to the ears of the user heart or other body sounds of a living subject examined therewith, the improvement comprising an impulse producer capable of producing a series of timed reference impulses having a frequency range of the order of the frequency of heart pulses of living subjects and which can be detected by the stethoscope user at the same time that heart pulses of a living subject being examined with the stethoscope can be heard by such user, means including a movable member for adjusting the frequency of the reference impulses produced by the impulse producer; and readout means indicating the frequency of the impulses produced by the impulse producer at any given position of the movable member, wherefore, movement of the movable member as necessary to synchronize the frequency of the reference impulses with that of heart pulses simultaneously detected by the user causes the readout means to indicate the frequency of said heart pulses when such synchrony is achieved.

### Claim 2 (depends on 1)

The stethoscope of claim 1 in which the impulse producer produces audible reference impulses.

### Claim 3 (depends on 1)

The stethoscope of claim 1 wherein the impulse producer produces visual reference impulses.

### Claim 4 (depends on 1)

The stethoscope of claim 1 having means for producing a series of visual signals responsive to a series of heart pulses sensed thereby, and wherein the impulse producer produces visual reference impulses.

### Claim 5 (depends on 1)

A stethoscope of claim 1 wherein the position of the movable member is manually adjustable.

### Claim 6 (depends on 1)

The stethoscope of claim 1 wherein the impulse producer and readout means are incorporated with the pickup head of the stethoscope.

### Claim 7 (depends on 1)

The stethoscope of claim 1 having means for producing a series of visual signals responsive to a series of heart pulses sensed thereby, and the impulse producer includes means for producing visual reference impulses at a position juxtaposed to that at which said visual signals are produced.

### Claim 8 (depends on 1)

The stethoscope of claim 1 having means for manually activating and deactivating the impulse producer.