JPH1024033A - Electrostethograph - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent noises, caused when an electrostethoscope, for hearing body sounds by bringing its sound collecting part into contact with the surface of the body, makes contact with the surface of the body, from coming out of loudspeakers or headphones as loud sounds by providing the sound collecting part with a timing control function whereby muting is canceled a predetermined time after the sound collecting part makes contact with the surface of the body. SOLUTION: Weak body sounds, detected by a sound collecting part 3, are received by a microphone 1 and converted into voice signals. The body sounds converted into the voice signals are amplified by a microamplifier 5 and input to a power amplifier 7 via a mute circuit 6. A mute switch 2 is provided in a position on the surface of the sound collecting part 3 which makes contact with the surface of the body, and when the surface of the sound collecting part 3 making contact with the body makes contact with the surface of the body and the mute switch 2 is turned on, its output signal is fed, to a mute timing control circuit 11; after the sound collecting part 3 makes contact with the body, the mute circuit 6 is turned on, and then turned off after a predetermined time has elapsed, so that noises caused during the contact are prevented from coming out of headphones.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an electric stethoscope.

[0002]

2. Description of the Related Art In a conventional electric stethoscope, the output level is not controlled while the sound pickup unit is in contact with the body surface.

[0003] Japanese Patent Application Laid-Open No. 60-261439 is related to these.

[0004]

The prior art electric stethoscope has the following problems. That is, since the output level is lowered depending on whether the sound collecting unit of the electric stethoscope is in contact with the body surface, noise when the contact state between the sound collecting unit and the body surface at the start or end of the auscultation becomes unstable is reduced. It sounds as loud as it is.

This problem can be solved by controlling the timing of muting the output of the electric stethoscope.

[0006]

According to the present invention, there is provided a timing control circuit for controlling the timing of muting an electric stethoscope.

In the electric stethoscope of the present invention, the output signal is muted until a certain time from when the sound pickup section comes into contact with the body surface until the contact pressure is stabilized by the timing control circuit. The noise at the time can be prevented from being emitted as a loud sound from speakers or headphones.

[0008] In addition, by setting the mute again after an arbitrary time, it is possible to prevent noise in a state where the contact pressure is unstable when the sound pickup unit is separated from the body surface from being output as loud noise from speakers or headphones. Can be prevented.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First, an embodiment according to claim 1 will be described. FIG. 1 shows one embodiment of the present invention, and shows the outer shape of an electric stethoscope. FIG. 2 is a block diagram thereof, and FIG. 3 is a timing chart thereof. The electric stethoscope includes a sound collection unit 3 and an amplifier 4. The sound collection unit 3 includes a microphone 1 and a mute switch 2 as input means. The amplifier 4 includes a microphone amplifier 5, a mute circuit 6, a mute timing control circuit 11, a power amplifier 7, a power supply 8, and an output terminal 9.

The weak body sound detected by the sound pickup unit 3 is received by the microphone 1 and converted into an electric sound signal. The body sound converted to the electric sound signal is amplified by the microphone amplifier 5 and is passed through the mute circuit 6 to the power amplifier 7.
Input. The power amplifier 7 is an amplifier that can also drive a speaker or headphones. The output signal of the power amplifier 7 is output from the output terminal 9. The mute circuit 6 is controlled by the mute timing control circuit 11.

The mute switch 2 is located on the contact surface side of the sound pickup unit 3 with the body surface. When the contact surface side of the sound pickup unit 3 with the body surface contacts the body surface, the mute switch 2 is pressed by the body surface. Mute switch output signal 2
8 is input to the mute timing control circuit 11. The mute timing control circuit 11 turns on / off the mute circuit 6 using the mute switch output signal 28 as a trigger.
This is a circuit that controls turning off. The operation of the mute timing control circuit 11 will be described with reference to the timing chart of FIG. The state of the mute switch output signal 28 is set to a high level when the mute switch 2 is not pressed, and to a low level when the mute switch 2 is pressed. When the output signal 27 of the mute timing control circuit is at a high level, the mute circuit 6 is turned on. When the output signal 27 is at a low level, the mute circuit 6 is turned off. The horizontal axis indicates time. The time when the mute switch 2 is pressed by the body surface when the contact surface side of the sound pickup unit 3 with the body surface contacts the body surface is T1, the mute timing control circuit output signal 27 becomes low level, and the mute circuit 6 is turned off. At time T2, the contact surface side of the sound pickup unit 3 with the body surface is separated from the body surface, the mute switch output signal 28 goes high, the mute timing control circuit output signal 27 goes high, and the mute circuit 6
Is turned on at time T3. The mute timing control circuit 11 is a circuit that sets the mute timing control circuit output signal 27 to low level at T2 after an arbitrary time from time T1 when the mute switch output signal 28 becomes low level. In addition, at time T3 when the mute switch output signal 28 becomes high level, the mute timing control circuit output signal 27 becomes high level without time delay.

In this embodiment, a signal is output from the output terminal 9 at an arbitrary time after the operator brings the sound pickup unit 3 into contact with the body surface. Also, noise until the contact pressure is stabilized is reduced to the output terminal 9.
Can be easily suppressed.

Next, a second embodiment will be described. FIG. 1 shows one embodiment of the present invention, and shows the outer shape of an electric stethoscope. FIG. 2 is a block diagram thereof, and FIG. 4 is a timing chart thereof. The electric stethoscope includes a sound collection unit 3 and an amplifier 4. The sound collection unit 3 includes a microphone 1 and a mute switch 2 as input means. The amplifier 4 includes a microphone amplifier 5, a mute circuit 6, a mute timing control circuit 11, a power amplifier 7, a power supply 8, and an output terminal 9.

The mute switch 2 is located on the contact surface side of the sound pickup unit 3 with the body surface. When the contact surface side of the sound pickup unit 3 with the body surface contacts the body surface, the mute switch 2 is pressed by the body surface. Mute switch output signal 2
8 is input to the mute timing control circuit 11. The mute timing control circuit 11 turns on / off the mute circuit 6 using the mute switch output signal 28 as a trigger.
This is a circuit that controls turning off. The operation of the mute timing control circuit 11 will be described with reference to the timing chart of FIG. The state of the mute switch output signal 28 is set to a high level when the mute switch is not pressed, and to a low level when the mute switch is pressed. When the output signal 27 of the mute timing control circuit is at a high level, the mute circuit 6 is turned on.
Turn off. The horizontal axis indicates time. The contact side of the sound pickup unit 3 with the body surface contacts the body surface and the mute switch 2
The time at which is pressed by the body surface is T1, the time at which the mute timing control circuit output signal 27 goes low and the mute circuit 6 is turned off is T2, and the contact surface side of the sound pickup unit 3 with the body surface is separated from the body surface. The time at which the mute switch output signal 28 goes high is T4, and the time at which the mute timing control circuit output signal 27 goes high to turn on the mute circuit 6 is T3.

The mute timing control circuit 11 detects the time T1 when the mute switch output signal 28 goes low.
This is a circuit that sets the mute timing control circuit output signal 27 to a low level at T2 after an arbitrary time from. Thereafter, when the set arbitrary time T3 is T3 <T4, the mute timing control circuit output signal 27 goes high at time T3 regardless of the state of the mute switch output signal 28. If T3> T4, the mute timing control circuit output signal 27 is not delayed at time T4 when the mute switch output signal 28 becomes high level.
Is a high level circuit.

In this embodiment, a signal is output from the output terminal 9 at an arbitrary time after the operator brings the sound pickup unit 3 into contact with the body surface. Further, noise until the contact pressure becomes stable can be suppressed. Also, by setting the time for listening to the body sound, the output signal is muted while the sound pickup unit 3 is in contact with the body surface, and the contact pressure when the sound pickup unit 3 is separated from the body surface is unstable. It is possible to easily suppress the noise from being output from the output terminal 9 in a normal state.

[0018]

According to the present invention, it is possible to automatically mute noise when the contact state between the sound collecting unit and the body surface becomes unstable at the start of auscultation of the electric stethoscope. In addition,
It is possible to automatically mute the noise when the contact state between the sound collection unit and the body surface after the auscultation becomes unstable.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an electric stethoscope according to one embodiment of the present invention.

FIG. 2 is a block diagram of one embodiment of the present invention.

FIG. 3 is a timing chart of one embodiment of the present invention.

FIG. 4 is a timing chart of another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Microphone, 2 ... Mute switch, 3 ... Sound pickup part, 4 ... Amplifier, 5 ... Microphone amplifier, 6 ... Mute circuit, 7 ... Power amplifier, 8 ... Power supply, 9 ... Output terminal, 11 ... Mute timing control circuit.

Claims (2)

[Claims] 1. An electric stethoscope for listening to a body sound by bringing a sound pickup unit into contact with a body surface, wherein the stethoscope has a timing control function for releasing a mute at an arbitrary time after the sound pickup unit comes into contact with the body surface. An electric stethoscope characterized by the above. 2. The electric stethoscope according to claim 1, further comprising a timing control function for muting again after an arbitrary time from when the mute is released by the contact of the sound pickup section with the body surface.