JPH0323169B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a respiratory monitoring device that automatically detects abnormalities in breathing rate and breathing sounds and issues an alarm or display.

In general, patients whose lives are at risk, such as trauma requiring emergency rescue, acute respiratory failure, shock, cerebrovascular accident, impaired consciousness due to severe disease, or postoperative surgery, require close monitoring. For this purpose, information from the patient such as electrocardiogram, blood pressure,
It is necessary to continuously monitor vital signs such as heart rate, breathing, and body temperature 24 hours a day to understand the patient's condition and provide appropriate treatment.

Among these, respiratory monitoring such as respiratory rate and breathing sounds is extremely important clinically. Currently, methods of respiratory monitoring commonly used include impedance plethysmography, inductance plethysmography, and the like. However, since these methods monitor the respiratory movement of the thorax, if the respiratory movement is maintained even if the airflow movement is stopped, there is a risk that detection of abnormalities may be delayed. On the other hand, since monitoring of tracheal sounds or respiratory sounds reflects the state of airflow within the trachea, reliable monitoring can be performed and is extremely important for respiratory management. Further, information on the presence or absence of phlegm retention in the airways, wheezing, coughing, etc., which are precursor symptoms of respiratory abnormalities, cannot be detected using conventional methods.

The respiratory monitoring device of the present invention not only measures and monitors the respiratory rate by detecting tracheal sounds or breathing sounds, but also detects respiratory abnormalities such as sputum tangles, coughs, and tracheal wheezing, so that they can be detected by doctors. The system records information in a format that is easy for doctors and nurses to use, and also provides warnings or displays, thereby reducing the burden on doctors and nurses.

The respiratory monitoring device of the present invention includes a microphone that detects tracheal sounds or respiratory sounds, and is activated when a sound of a certain level or higher is input from the microphone, and records the output of the microphone for a certain period of time. At the same time, frequency analysis or waveform analysis of the breathing sounds detected by a microphone and a breathing sound recording device that records the number of activations and the time of occurrence is performed, and based on this, the presence or absence of abnormal sounds due to sputum entanglement, etc. is detected. A breathing rate monitoring device including a breathing sound monitoring device, a sound pressure level meter for extracting a breathing curve from the sound pressure level output from a microphone, and a counter for calculating a breathing rate from the output of the sound pressure level meter; an arithmetic control device that outputs a signal when an abnormality in the breathing sounds and breathing rate from the monitoring device and the breathing rate monitoring device is determined;
The device is characterized by comprising an alarm/display device connected to the arithmetic and control device to notify abnormalities in breathing sounds and breathing rate.

Embodiments of the present invention will be described in detail below based on the drawings.

The breathing monitoring device shown in FIG. 1 is composed of a microphone 1, a breathing sound recording device 2, a breathing sound monitoring device 3, a breathing rate monitoring device 4, an arithmetic and control device 5, and an alarm/display device 6.

The microphone 1 is attached to the upper neck skin surface of the trachea to detect tracheal sounds, or is attached to the chest to detect respiratory sounds.

The respiratory sound recording device 2 is strengthened when the sound pressure level increases due to airflow in the airways due to coughing, when secretions adhere to the inner wall of the airways due to sputum entanglement, or when the airways become narrowed. This is a device that records sound at a high level of noise.

As shown in FIG. 2, this breathing sound recording device 2 includes a voice-controlled tape recorder 21 that includes a converter 22 connected to the microphone 1, a delay circuit 23, a counter 24, and a timer 25. This tape recorder 2
1 records sounds such as coughing for a certain period of time (for example, 10 seconds) by being activated when a sound above a certain trigger level is input, and the output of microphone 1 is used as a reference by converter 22. Recording is started with the output of the comparator 22 obtained when it exceeds the reference value, and the microphone output input to the tape recorder 21 is slightly delayed in the delay circuit 23. The microphone output is configured to be able to record from the moment when the microphone output exceeds a reference value, that is, from immediately before a cough or the like begins.

In the tape recorder 21, the sound from the microphone 1 is directly recorded in one channel by its operation, and at the same time, the number of activations and the time of occurrence are recorded in the other channel. A counter 24 and a timer 25 are built in to measure the number of times the sound is generated.

This tape recorder 21 is connected to the arithmetic and control unit 5 to process information regarding breathing sounds including coughing, etc., but it is also connected to a monitor device equipped with a printer to directly print out the recorded information regarding breathing sounds. It is desirable to be able to do so.

Information regarding the breathing sounds recorded by the breathing sound recording device 2 is used by a doctor when diagnosing the patient's medical condition based on alarms etc. from the breathing sound monitoring device 3 and the breathing rate monitoring device 4, which will be described later. It is something that will be done. In particular, monitoring patients at night places a heavy burden on doctors and nurses, but the above-mentioned respiratory sound recording device 2 can reduce this burden and at the same time monitor only the necessary areas where coughs, etc. exceeding a certain level are occurring. Since it can be recorded on the tape recorder 21, commercially available cassette tapes can be used, and
Since only the parts of abnormal breathing sounds necessary for respiratory monitoring are automatically recorded, it does not require a long time to review the recorded content.

The breathing sound monitoring device 3 is a device for determining whether tracheal sounds or breathing sounds are normal or abnormal.

As shown in FIG. 3, this breathing sound monitoring device 3 is equipped with a transient recorder 31 that records breathing sounds for several seconds, and is used to determine whether the recorded breathing sounds are normal or abnormal. A part of the arithmetic and control unit 5 is used for this purpose.

The breathing sound monitoring device 3 detects whether or not the breathing sounds are abnormal breathing sounds by performing frequency analysis or waveform analysis of the breathing sounds. After breathing sounds are once recorded on the transient recorder 31 using a microphone attached to the camera, etc., the sounds are sent to the arithmetic and control unit 5.

For example, in patients who have fallen into a coma or patients who have undergone surgery, it is difficult to expectorate, so it is extremely common to hear strong noisy sounds due to the accumulation of secretions in the airways during auscultation. By the way. The vibration waveform of the sound caused by sputum entanglement is a relatively regular vibration, and due to the vibration of secretions attached to the bronchial wall, it contains unique vibration waveform frequencies such as low frequency vibrations of 30Hz to 100Hz. ing. Therefore, by frequency analysis or waveform analysis using this,
Sputum entanglement and the like can be easily detected, for example, by comparing the frequency distribution of normal breathing sounds and the frequency distribution of sputum entangled breath sounds.

Therefore, the arithmetic and control unit 5 performs frequency analysis or waveform analysis of the input breath sounds, and uses parameters representing the frequency distribution and waveform characteristics to represent the normal frequency distribution and waveform characteristics stored in advance. It is compared with parameters or data such as phlegm tangles to detect whether sputum tangles are present or not, thereby determining whether the breathing sounds are normal or abnormal.

If the arithmetic and control device 5 determines that there is an abnormality, an alarm lamp, alarm buzzer, indicator light, or other alarm/display device 6 issues an alarm/display to indicate the abnormal state. In this case,
It is also possible to issue multiple warnings and displays depending on the degree of abnormality in breathing sounds.

The main purpose of monitoring abnormal breathing sounds is to detect in advance the possibility of death due to suffocation due to phlegm.From this perspective, even if breathing sounds are constantly detected, However, since it is generally not the case that a person suffocates to death due to phlegm, breathing sounds may be detected every 1 to 2 minutes and analyzed to see if they are abnormal breathing sounds. Therefore,
The data intermittently detected by the transient recorder 31 can be transferred slowly to the arithmetic and control device 5, thereby eliminating the need for a large arithmetic and control device and allowing processing to be performed by a small arithmetic and control device. be able to.

Moreover, abnormal breathing sounds do not necessarily reach the trigger level of the voice-controlled tape recorder, and therefore, the tape recorder may not operate when abnormal breathing sounds occur. However, since the data at the time of occurrence of abnormal breathing sounds is highly important, when abnormal breathing sounds are detected in the arithmetic and control unit, the remote control equipment is used while the abnormal breathing sounds are being detected. The device is configured to forcibly drive a voice control tape recorder.

As shown in FIG. 4, the respiration rate monitor device 4 includes:
This is for monitoring the respiratory rate based on the output of the microphone 1 attached to the skin surface of the upper neck of the trachea, and from the vibration waveform of the tracheal sound or breathing sound output from the microphone, the envelope of the waveform, i.e. From the sound pressure level meter 41 that extracts the breathing curve and the breathing curve obtained from the sound pressure level meter 41,
It is equipped with a low frequency counter 42 that continuously measures periodic components and calculates the number of breaths within a unit time.

This low frequency counter 42 is connected to the arithmetic and control device 5, and the arithmetic and control device compares the respiration rate, which is the output of the low frequency counter, with a preset abnormal value, and when the respiration rate reaches the abnormal value. Breathing sound data for alarm is also as important as the data when abnormal breathing sounds occur. Therefore, at the same time as the above alarm, the voice control tape recorder is switched to continuous operation by the remote control device, and the breathing sound data is The device is configured to constantly monitor sound. However, when abnormal breathing sounds are detected in the breathing sound monitoring device, it is difficult to accurately measure the breathing rate, so it is necessary to ignore the breathing rate measurement data regarding the above-mentioned alarm. In the arithmetic and control device described above, a first abnormality level that requires some attention is set above and below the normal breathing rate, and a second abnormality level is further set above and below the normal breathing rate, and the alarm is issued in stages. It can also be configured as The arithmetic control device 5 manages the signals from the devices 2, 3, and 4, and controls the operation of each of these devices. If it is determined that there is an abnormality in the breathing rate, a signal is sent to the alarm/display device 6 to notify that there is an abnormality. The alarm/display device 6 connected to the arithmetic control device 5 to notify abnormalities in breathing sounds and breathing rate includes not only an alarm lamp and an alarm buzzer, but also a CRT monitor and a CRT monitor that displays various types of information printed or tabulated on recording paper. It is also possible to use an output device or the like that displays the image.

Further, the aforementioned microphone is attached to a patient in a hospital room, but other equipment is placed away from the bedside, for example, in a nursing center, and the two are connected by wire or an FM transmitter/receiver.

Note that dotted arrows in FIG. 1 indicate the flow of control signals.

In the respiratory monitoring device having the above configuration, by detecting tracheal sounds or respiratory sounds, it is possible not only to measure and monitor the respiratory rate but also to constantly check for abnormal sounds such as sputum entanglement and coughing. Therefore, for example, it is possible to detect sputum entanglement as a precursor to abnormal breathing rate, and in this case, although there is no change in breathing rate, abnormal sounds may be detected by the breathing sound monitoring device. This makes it possible to treat the abnormal sound as a sign of an abnormal respiratory rate and take appropriate measures for the patient.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the respiratory monitoring device according to the present invention, and FIGS. FIG. 2 is a block configuration diagram of a number monitoring device. 1...Microphone, 2...Breathing sound recording device,
3... Breathing sound monitoring device, 4... Breathing rate monitoring device, 5... Arithmetic control device, 6... Alarm/display device, 21... Tape recorder, 31... Transient recorder, 41... Sound pressure Level meter, 42
……counter.

Claims (1)

[Scope of Claims] 1. A microphone that detects tracheal sounds or breathing sounds, which is activated when a sound of a certain level or higher is input from the microphone, records the output of the microphone for a certain period of time, and records the number of activations. A breathing sound recording device that records the time of occurrence of breathing sounds, and a breathing sound monitoring device that performs frequency analysis or waveform analysis of the breathing sounds detected by a microphone and detects the presence or absence of abnormal sounds due to sputum entanglement based on the frequency analysis or waveform analysis of the breathing sounds detected by a microphone. , a breathing sound monitoring device equipped with a sound pressure level meter that extracts a breathing curve from the pressure level of the output of the microphone and a counter that calculates the breathing rate from the output of the sound pressure level meter; and the above-mentioned breathing sound monitoring device and breathing rate monitor. an arithmetic control device that outputs a signal when an abnormality in the breathing sounds and breathing rate from the device is determined; an alarm/display device that is connected to the arithmetic and control device and notifies abnormalities in the breathing sound and breathing rate; A respiratory monitoring device characterized by comprising: