JPS61358A - Respiration monitor apparatus - 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] [Technical Field of the Invention] The present invention relates to a respiratory monitoring device used for a living body connected to a respirator, and is particularly characterized in identifying the exhalation start point and the inspiration start point. It is something.

[Technical background of the invention and its problems]

In recent years, with the development of data processing devices such as microconbeaters, respiration monitoring devices can process respiration data such as respiratory flow rate of living organisms, calculate respiration parameters, display numerical values along with respiration waveforms, and monitor long-term Devices that can display trend graphs showing changes, correlation charts showing interrelationships of data, etc. are emerging. In order to calculate respiratory parameters, it is essential to identify the start point of inspiration and the start point of expiration.
It can be said that the accuracy and stability of the calculated data are determined by this identification.

In the prior art, an inhalation start point or an exhalation start point is identified when respiration data such as respiratory flow rate exceeds a predetermined threshold or exceeds a predetermined threshold for a predetermined time. However, the respiration data obtained from living organisms is superimposed with mechanical noise from ventilators, random noise from electrical circuits, noise from heartbeat, etc., and the respiration rate varies widely from 10 breaths/minute to 60 breaths/minute. However, with conventional methods, it has been difficult to accurately identify the inhalation start point and exhalation start point.

Therefore, it was not possible to accurately and stably calculate the respiration/grammeter.

[Purpose of the invention]

This invention calculates accurate and stable respiratory parameters,
In order to display the data, it is possible to stably display the starting point of inspiration, without being affected by noise superimposed on the breathing data, especially noise caused by heartbeat.
The purpose is to identify the starting point of exhalation.

[Summary of the invention]

In this invention, when respiratory data exceeds a predetermined first threshold value and exceeds a second threshold value larger than the first threshold value after a predetermined 7 hours have passed since the respiratory data exceeds the threshold value, an inhalation start point or an expiration start point is determined. By doing this, you can accurately determine the starting point of inspiration,
It identifies the starting point of exhalation.

This T time is set to remove the influence of noise such as heartbeat. The cycle THR' in which the heartbeat affects the respiratory data is about 4 times the heartbeat cycle THR. The neck breathing cycle TRR is usually about three times the heartbeat cycle THR. From these, ~3 THR'~/4 THR TRR 3 THR 1., THR' 1/4TFLR are obtained. Therefore, it can be seen that in order to eliminate the influence of heartbeat noise, it is sufficient to set the T time to approximately one time period of the respiratory cycle TRR.

〔Effect of the invention〕

According to the invention, it is possible to identify both the inhalation start point and the exhalation start point without being affected by various noises such as noise caused by heartbeat superimposed on breathing data, allowing accurate and stable breathing.
By calculating and displaying parameters, it is possible to accurately understand the patient's medical condition (!).Also, when a ventilator is used for a patient, it is possible to accurately understand the operation of the ventilator. Helpful.

[Embodiments of the invention]

FIG. 1 is a block diagram of one embodiment of a respiratory monitoring device according to the present invention. One end of the transducer 2 is connected to a tracheal insertion tip inserted into the airway of the living body 1, and the other end of the transducer 2 is connected to a respirator 3. A KI-1 ultrasonic transducer is provided in TransteUser 2,
The ultrasonic signal generated by this vibrator is transmitted via a pipe 4 to a respiratory flow meter 5 using an ultrasonic propagation time difference method.

The output signal of the pneumotachograph 5 is supplied to a converter 7 in a signal processing device 6 . In the signal processing device 6, there is further C.
PU (microprocessor) 8, lROM 9, RA
M 10 and video RAM 13 are also provided, and these are connected via a pass line 11. The signal processing device 6 is controlled by a CPU 8, and its processing is performed by a ROM.
This is done according to the zologram stored in 9. Note that a key 12 is connected to the pass line 11. Further, the output of the video RAM 13 is supplied to a video monitor 14 as a display device.

Next, the operation of this embodiment will be explained with reference to the flowchart shown in FIG. The output signal of the pneumotachograph 5 is supplied to the A/D converter 7 in the signal processing device 6, and the signal processing device 6 simultaneously collects the output signal of the pneumotachograph 5.
The inhalation start point and expiration start point are determined, and signal processing is performed to calculate various respiratory parameters (breathing rate, ventilation volume, etc.).

This task uses a constant sampling period (e.g. 10m5
ec) is started every time the conversion of the A/D converter 7 is completed, and the flag is initially set to 0. When the process is started at a start step 200, respiratory flow rate data is read into the CPU S from the A/D converter 7 at a step 201. R here ■1
0, respiratory flow rate data is sequentially updated and stored.

Next, in step 202, it is determined whether the flag is 0 or not. If the flag is O, it is determined in step 203 whether the negative flow velocity has continued for 250 m5ec (respiration cycles are distributed from 1 to 6 seconds, but 14 times in this short case). This determination is made based on whether the data read from RAM I O represents a negative flow velocity. If not, the task is terminated at end step 204.

If it continues, the flag is set to 11C in step 205, and then this task ends. Negative flow rate is 25
The period lasting 0 m5ec is the expiration period and indicates that the first expiration period has been detected.

If the exhalation period is detected, then the flags are switched between 1 and 2 and the inhalation start point and exhalation start point are determined in steps 206 to 212. Further, in step 213, it is determined whether or not a starting point has been detected. If the starting point is detected, in step 1214, various respiratory parameters are calculated from the data for one waveform, and according to instructions from the keyboard 12. Video RAM 13 =
i is displayed on the video monitor 14. FIG. 3 shows a display example of instantaneous data of the respiratory flow rate waveform and ventilation volume, and FIG. 4 shows a display example of trend data of the respiratory rate and ventilation volume.

1, Step 2] In step 4, respiration cycle data used for detecting the inhalation start point and expiration start point, which will be explained below, is also calculated.

Next, with reference to the output signal waveform of the pneumotachograph 5 in FIG. 5 and the flowchart in FIG. 6, the STELLA f207.
The operation of the task of finding the inhalation start point and exhalation start point corresponding to 208 will be explained. Since the inspiratory start point and the expiratory start point can be detected by reversing the sign of the respiratory flow rate, only the inspiratory start point will be described.

In FIG. 5, the broken line indicates the O level, with the upper side indicating the positive level and the lower side indicating the negative level. The direction of the respiratory flow rate is positive during the inspiratory period and negative during the expiratory period. In order to start inhalation, it is necessary for the respiratory flow rate to fall below a value of 0, but around 0 it is unstable and the heart rate, ? ±10 ml due to noise due to movement! /sec~±13m1y's e
It is necessary to consider about c.

Therefore, in step 601 it is determined whether a threshold set above the noise level, for example 10 mVsec, is exceeded. If 10 mVsec has not been exceeded, a flag indicating that 10 mVsec has been exceeded is first reset to OVC in step 602, and the task ends in step 603. If it exceeds 1.01114/see f, it is determined in step 604 whether it has been exceeded for the first time, and if it has exceeded it for the first time, it may be the start point of intake in step 605, so the start point is set and step At 606, the flag is set to 1, and this task ends.

If it is not the first one crossed, i.e. a possible start point of inspiration is stored, step 60
At 7, a predetermined time T (time corresponding to 14 of the breathing cycle)
It is determined whether the period has elapsed. If it has not elapsed, the task ends, and if one elapsed, Step 08 determines whether the second one threshold value (a value that is determined to be sufficient inspiration, for example, 100 m1./5ee) has been exceeded. do. If it has not been exceeded, the flag is cleared to O in step 0609, and the process ends. If it has exceeded the limit, it is recognized at step 610 that the intake phase has entered, and the point set at step 605 is identified as the intake start point.

Note that the 14 hours of the breathing cycle in step 607 are determined in step 21.1 of FIG.
It is assumed that c is set to c.

In the above embodiment, the predetermined time T is controlled by the breathing cycle, but if the heartbeat cycle is obtained,
It goes without saying that the predetermined time T may be controlled by the heartbeat cycle (C).

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the respiratory monitoring device according to the present invention, FIG. 2, FIG. b), 4th
Figures (a) and (b) are waveform diagrams showing examples of display in the same embodiment, and Fig. 5 is a waveform diagram showing an example of respiratory flow velocity waveforms in the same embodiment. ]...Living body, 2...Transducer, 3...Respirator, 4...Rigive, 5...Respiratory current meter, 6...
・・Signal processing bag rlt, 7・・A/D converter, 8・
...CPU, 9...ROM, 10...RAM, 1
．． 1...pass line, 12...keychain, 13...
-Video Ram, 14...Video monitor. Agent Patent Attorney 1) Haru Kitatake Figure 1 Figure 2

Claims (4)

[Claims] (1) In a respiration monitoring device comprising a device that collects respiration data of a living body, a signal processing device that calculates respiration parameters from the collected respiration data, and a display device connected to this signal processing device, the signal processing After the respiratory data exceeds the first threshold for determining inhalation or the second threshold for determining exhalation having the opposite polarity to the first threshold, the device detects the first threshold after a predetermined time period T has elapsed. means for identifying an inhalation start point or an expiration start point when a third threshold greater than a threshold or a fourth threshold having a polarity opposite to the third threshold is exceeded; A respiratory monitoring device characterized by having means for calculating respiratory parameters based on points. (2) The respiratory monitoring device according to claim (1), wherein the T time is controlled by the respiratory cycle. (3) The respiratory monitoring device according to claim (1), wherein the T time is controlled by the heartbeat cycle. (4) The respiratory monitoring device according to claim (1), (2) or (3), characterized in that respiratory flow rate is used as the respiratory data.