JP2560123Y2 - Ultrasound Doppler device for monitoring heart rate respiration - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic Doppler device, and more particularly to an ultrasonic Doppler device capable of simultaneously acquiring a heartbeat signal and a respiratory signal.

[0002]

2. Description of the Related Art Conventionally, as a device for monitoring the health condition of a newborn baby, a device integrated with a respiration monitor, a heart rate electrocardiograph monitor, a heart rate respiration monitor, or a tissue oxygenation method called an oxygen partial pressure method is used. It was a combination of methods for measuring saturation.

[0003] A respiratory monitor is also effective for finding sleep apnea syndrome, which has recently become a problem. As a respiratory monitor, respiratory monitoring using respiratory sounds is considered to be a correspondingly reliable method.

On the other hand, it is said that a method of monitoring a heartbeat is to collect an electrocardiogram. Of interest are the R-waves and R-waves at the highest compression ratios.
It is a method that takes the form of the time interval of the waves or the instantaneous heart rate per heart beat.

Conventionally, this electrocardiographic system has been used in combination with a respiratory monitor such as an impedance respirometer, a respiratory sound detecting device, a respiratory airflow detecting device using a thermistor at the nose tip, or a torso change measuring device. Was.

[0006]

In the above-described detection apparatus, the electrocardiographic monitor uses a method of collecting biological signals using electrodes, and electrodes as sensors must be attached to various parts of the living body. If an impedance respirometer is used on top of that, further electrodes are required. In particular, the impedance respirometer measures the lungs that inhale air,
Alternatively, respiration is monitored by a change in impedance between the lungs exhaling air and the inflated surroundings, and there is a problem in its credibility.

The present invention has been made in view of the above points, and has as its object to provide an ultrasonic Doppler for heartbeat respiration monitoring capable of simultaneously acquiring a highly reliable heartbeat signal and a respiration signal by a single sensor. It is to implement the device.

[0008]

According to the present invention, a single probe for transmitting and receiving CW signals for simultaneously acquiring a Doppler shift caused by heartbeat and respiration, and an output signal of the probe. A detector for extracting a Doppler component, a first filter having a characteristic of passing a predetermined frequency component for extracting a blood flow component from a Doppler signal output from the detector,
A second characteristic having a characteristic of passing a predetermined frequency component for extracting a respiratory sound component from the Doppler signal output from the detector.
, A first envelope detector for detecting an output of the first filter to output a heartbeat pulse, and detecting an output of the second filter to output a respiratory sound wave signal And a second envelope detector.

[0009]

A single probe transmits an ultrasonic CW signal and receives a signal Doppler-shifted due to heartbeat and respiration. From this signal, a Doppler component is extracted by a detector. The Doppler component is filtered by a first filter to remove high-frequency components and frequency components of approximately 1000 Hz or less, and detected by a first envelope detector to output a heartbeat pulse.

[0010] Of the Doppler components, a frequency component of 50 to 500 Hz passes through the second filter, is detected by the second envelope detector, and a respiratory sound waveform signal is output. The probe can simultaneously obtain two signals, heartbeat and respiration.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention. In the figure, 1 is an oscillator for generating a signal for transmission, and 2 is an electric signal for transmission which is converted into an ultrasonic signal and transmitted, and a reflected wave from a reflector is received and converted into an electric signal. Probe. When this is attached near the carotid artery of the subject, the heartbeat picks up the blood flow from the carotid artery, and the breathing sound picks up the vibration of the tissue with the Doppler system. When attached to the chest, the heartbeat detects the heart or blood flow, and the breathing sound detects the vibration of the sternum or the lung surface as the Doppler signal. Reference numeral 3 denotes a preamplifier for amplifying a reception signal from the probe 2, and reference numeral 4 denotes a detector that extracts only the Doppler shift from the reception signal and outputs heartbeat and respiratory sound components. The output corresponding to the detected Doppler shift is amplified by the low frequency amplifier 5.

In this manner, a heartbeat, that is, a pulse wave is obtained from the Doppler shift of the blood flow, and a respiratory sound is obtained from the vibration of the throat and the sternum. The circuit from the oscillator 1 to the low frequency amplifier 5 is an ordinary CW Doppler system.

Reference numeral 6 denotes a bandpass filter which passes a low frequency region of 1000 Hz or more and removes high frequency components remaining in the output of the detector 4, and 7 denotes a bandpass filter B which passes a low frequency in the range of 50 Hz to 500 Hz. is there. Numeral 8 denotes an envelope detector A for detecting a signal from the bandpass filter A6 and outputting a heartbeat pulse-like pulse wave. The output signal waveform is the pulse waveform shown in FIG. Reference numeral 9 denotes an envelope detector B for detecting a signal from the bandpass filter B7 and outputting a respiratory sound waveform shown in FIG. Envelope detector A8 and envelope detector B
The output of No. 9 is sent to a signal processing circuit and a recording unit at a subsequent stage, not shown.

Next, the operation of the embodiment configured as described above will be described. The oscillator 1 generates a high-frequency CW wave to operate as a CW Doppler device, and excites the probe 2 to transmit it to a subject. The probe 2 has a weak directivity,
It is attached to the neck or chest in one place. FIG. 3 shows the mounting location of the probe 2. FIG. 3 is a diagram illustrating an example of a mounting location. In the figure, A and B are figures attached to the vicinity of the carotid artery of the neck muscle, and either one is selected. The heartbeat at this position receives a pulse wave pulsating from the Doppler shift of the blood flow. In addition, when collecting breath sounds, the vibration value of the throat is picked up by a Doppler system. C and D are examples attached to the chest, where the heartbeat picks up the heart or blood flow, and the breathing sound picks up the vibration of the sternum or the surface of the lung. Attach to any one of the positions A, B, C, and D to perform transmission and reception. The direction in which the beam of the probe 2 enters and exits is rather conical, rather than perpendicular to the mounting surface, so that the range of sensitivity is wider and better. FIG. 4 shows the probe 2 and the radiation beam. In the figure, 1
Reference numeral 1 denotes an ultrasonic beam applied to the subject 12 from the probe 2 in which transducers are arranged concentrically.

The ultrasonic waves emitted from the probe 2 attached as described above are received and amplified by the preamplifier 3. From this output, a Doppler signal is extracted by a detector 4 and amplified by a low-frequency amplifier 5.

The band-pass filter A6 has a frequency of 1000 Hz from the output of the low-frequency amplifier 5 due to the fast moving blood flow or the motion of the heart wall.
Only the above Doppler component is extracted, and the extracted signal is detected by an envelope detector A8 to become a heartbeat pulse, which is output to a signal processing circuit and a recording unit at a subsequent stage.

The bandpass filter B9 extracts only the 50 Hz to 500 Hz Doppler component of the slow-moving respiratory sound component from the output of the low-frequency amplifier 5, and extracts the extracted signal from the envelope detector B9.
A signal based on the respiratory sound is detected at 9 and output to a signal processing circuit and a recording unit at the subsequent stage.

As described above, according to the present embodiment, the probe as a sensor is mounted at one place, and the reliability and credibility are better than those of the conventional impedance type.

In this embodiment, the object is achieved by mounting the sensor at one place. However, separate probes for heartbeat and respiration are used, and the elements in the probe are separated. It does not hinder.

[0020]

As described in detail above, according to the present invention, a single sensor can simultaneously acquire a heartbeat signal and a respiratory signal with high credibility, and the practical effect is great. .

[Brief description of the drawings]

FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention.

FIGS. 2A and 2B are output waveforms of an envelope detector, wherein FIG. 2A is a diagram of a heartbeat pulse and FIG. 2B is a diagram of a respiratory sound waveform.

FIG. 3 is a diagram showing a preferred example of a mounting location of a probe.

FIG. 4 is a diagram showing a concentric probe as a preferred probe and a beam shape thereof.

[Explanation of symbols]

 2 Probe 4 Detector 6,7 Bandpass filter 8,9 Envelope detector

Claims (1)

(57) [Scope of request for utility model registration] A single probe for transmitting and receiving CW for simultaneously acquiring a Doppler shift caused by heartbeat and respiration (2)
A detector (4) for extracting a Doppler component from an output signal of the probe (2); and a predetermined frequency component for extracting a blood flow component from a Doppler signal output from the detector (4). A first filter (6) having a characteristic of passing therethrough; and a second filter having a characteristic of passing a predetermined frequency component for extracting a respiratory sound component from the Doppler signal output from the detector (4). (7), a first envelope detector (8) that detects an output of the first filter (6) and outputs a heartbeat pulse, and detects an output of the second filter (7). And a second envelope detector (9) for outputting a respiratory sound waveform signal.