JPS61249444A - Air bag detector for detecting respiration - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a detection device for detecting the breathing state of a living body, and in particular to detecting the breathing state by electrically converting the amount of air movement by an air bag. The present invention relates to an air bag detector for detecting respiration.

"Prior Art" Electrocardiographs are effectively used to know the health condition of a patient, but when a patient's breathing is impaired, it is necessary to know the condition of the respiratory organs (lungs). The state of this respiratory organ can be ascertained by knowing the state of respiration (eg, respiratory rate, respiratory waveform).

By the way, when a living body breathes, the chest or abdomen moves.
In other words, the movement of the chest or abdomen can be said to represent the state of breathing. Therefore, if the movement of the chest or abdomen can be detected by some means, the state of the respiratory organs (lungs) can be known by detecting and recording the state of breathing.

This is an extremely effective non-invasive patient monitoring method that does not require actual surgery to know the inside of the lung.

From this point of view, impedance methods, nasal thermistor methods, and the like have been conventionally used to monitor a patient's breathing condition. The former impedance method determines the state of breathing by measuring the impedance of the surface of the body. That is, the impedance of the surface of the body changes as a result of breathing exercise, and the state of breathing is detected based on this change value.

The latter nasal thermistor system uses a small thermometer attached to the nasal cavity to measure changes in ambient temperature when breathing through the nose to determine the state of breathing.

``Problems to be solved by the invention'' By the way, it is possible to know the patient's breathing condition using this method. However, with the impedance method, for example, the breathing sensitivity is low, making it difficult to accurately detect breathing conditions such as when breathing is shallow, and because it is often used in conjunction with electrocardiograph electrodes, the mounting position is limited. There was a point.

In addition, the nasal cavity thermistor method requires a thermistor (thermometer) to be attached to the nose, which is not only unsightly but also painful if used for a long period of time.

"Means for Solving the Problems" Therefore, this invention was made by focusing on the above problems, and provides an air bag 1 that expands and contracts in response to the expansion and contraction of the chest or abdomen.
A vibrating membrane 12 that undergoes strain due to the amount of air movement caused by the air movement and causes a capacitance change between it and the return electrode plate 14, a field effect transistor 15 that reads this capacitance change as a voltage change, and a field effect transistor 15 in front of the vibrating membrane 12. a decompression film 1 for preventing the vibrating membrane 12 from being mechanically saturated when the amount of air movement exceeds the strain of the vibrating membrane 12;
The above problems can be solved by providing an air bag detector for respiration detection, which is equipped with The purpose is to solve the following points.

``Example'' Hereinafter, how the configuration of the present invention is actually embodied will be explained with reference to the drawings, together with its operation.

FIGS. 1 and 2 are cross-sectional views of an air bag detection device in which air bags are connected according to an embodiment of the present invention. In the figures, 1 is an annular air bag, and this air bag 1 has a sponge 2 and It includes a sponge cover 3 made of vinyl chloride, a collar piece 4, and an air guide pipe.

The sponge 2 of the airbag 1 is made of a soft and resilient polyurethane synthetic resin in which many continuous bubbles are formed, and a sponge cover 3 made of vinyl chloride covers the entire circumference of the pants. The air contained in the continuous foam is prevented from escaping.

Trousers covered with this sponge cover 3:) 2 is the fourth
As shown in Figure 5, it is placed in close contact with the chest and abdomen of the human body.
The sponge 2 also expands and contracts in response to the movements of the chest and abdomen as the human body breathes. That is, as the chest and abdomen expand and contract, the air existing in the foam inside the sponge 2 surrounded by the sponge cover 3 becomes an air flow and passes through the air guide tube 5 as shown in FIG. or be pushed outside or
It can be pulled back as shown in the figure.

An air connector 6 is attached to the other end of the air guide tube 5, as shown in FIG. As shown in FIGS. 4 and 5, this air connector 6 connects the air guide tube 5 to an air bag detector 7 for detecting the movement of air due to expansion and contraction of the sponge 2 and converting it into an electrical signal. It is for the purpose of

The air bag detector 7 electrically converts the movement of air caused by the expansion and contraction of the sponge 2 of the air bag 1.
An electret condenser microphone is fitted into the outer cylinder of a metal air connector, and the airflow moving as the air bag 1 expands and contracts is guided to the vibrating membrane of the electret condenser microphone, and movements of the abdomen or chest are detected by the electret condenser microphone. It is detected as a change in capacitance.

Therefore, the structure of this air bag detector 7 is shown in FIGS. 6 and 7.
To explain with the drawing, 8 is a cylindrical air connector outer cylinder, and an electret condenser microphone 9 is fitted downwardly into the lower part of the air connector outer cylinder 8.
An air chamber 8a is formed between the two. This electret condenser microphone 9 has a cylindrical electret condenser microphone outer tube 11 and a vibrating membrane 12, a bath 13, a return electrode plate 14, and a field effect transistor 1.
5 is housed, and the lower part is closed with a board 16. Further, a vacuum film 10 is placed on the electret condenser microphone outer cylinder 11.

The vibrating membrane 12 is distorted by the amount of movement of the air introduced into the air chamber 8a through the air guide tube 5 due to the expansion and contraction of the air bag 1, and a change in capacitance occurs between the vibrating membrane 12 and the return electrode plate 14. This capacitance change is read as a voltage change by passing through a field effect transistor, and is displayed as the number of respirations and a waveform by a device (not shown). By the way, the amount of distortion of the vibrating membrane 12 of the electret condenser microphone 9 is determined by its shape, so if the amount of air movement exceeds that amount of distortion, it will become mechanically saturated and the output voltage will become saturated. arise. In order to avoid this, a pressure reducing film 10 is placed in front of the vibrating membrane 12, and the sensitivity can be easily adjusted by changing the thickness and material of this pressure reducing film 10.

Next, the operation of the air bag detector 7 having the above configuration will be explained. First, as shown in FIGS. 4 and 5, the airbag 1 is tightly attached to the abdomen of a human body using adhesive tape. The air bag 1 that is in close contact with the person expands and contracts due to the expansion and contraction movement of the abdomen as the person breathes. That is, when the abdomen expands as shown in FIG. 4, the airbag 1 is compressed and compressed, and the air contained in the airbag 1 is transferred through the air guide tube 5 to the airbag as shown in FIG. It is sent into the air chamber 8a of the detection tool 7. The air sent into the air chamber 8a presses the vibrating membrane 12 via the decompression film 10.

Furthermore, when the abdomen contracts as shown in FIG. As shown in , the airbag 1 is pulled back, and the vibrating membrane 12 is also returned to its original position. This movement (strain) of the vibrating membrane 12 causes a capacitance change between it and the return electrode plate 14, and this capacitance change is detected as a voltage change through the field effect transistor 15, and this voltage change is displayed on a display (not shown). The respiratory status can be detected by visually checking the number and waveform.

[Effects of the Present Invention] According to the present invention, the air flow caused by the expansion and contraction of the airbag is detected by the electret condenser microphone, so that the detection sensitivity is good and the respiratory state can be accurately detected.

Furthermore, since the air pressure is detected through the vacuum film, there is no risk of mechanical saturation of the diaphragm, and there are advantages such as the ability to easily adjust the sensitivity by changing the thickness and material of the vacuum film.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the main parts of an airbag detection device that connects an inflated airbag, Figure 3 is a plan view of the entire airbag, and Figures 4 and 5 show the airbag being connected to the abdomen. FIG. 6 is a sectional view of the air bag detector, and FIG. 7 is an exploded perspective view of the air bag detector. 1... Air bag 7... Air bag detector 9... Electret condenser microphone 10
. . . Decompression film 12 . . . Vibration membrane 15 . . . Field effect transistor. Applicant Fukuda Denshi Co., Ltd. Agent Patent Attorney Junya Suzuki Figure 4 Figure 58

Claims (1)

[Claims] Airbag 1 that expands and contracts in response to expansion and contraction of the chest or abdomen
A vibrating membrane 12 that causes a change in capacitance between it and the strain return electrode 14 in response to the amount of air movement caused by the vibration, and a field effect transistor 15 that reads this capacitance change as a voltage change.
and an electret condenser microphone 9 located in front of the vibrating membrane 12 to prevent the vibrating membrane 12 from becoming mechanically saturated when the amount of air movement exceeds the strain of the vibrating membrane 12. An air bag detector for respiration detection, comprising a film 10 for decompression.