JPS5875562A - 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 The present invention relates to a respiratory monitoring device that is applied to a living body connected to a respirator.

In recent years, remarkable progress has been made in respiratory science, making it possible to perform operations on the circulation, respiratory system, or central nervous system, which were previously difficult, and contributing to the advancement of medical care. The development of ventilators is responsible for this development.The most important thing when using a ventilator to breathe is to detect whether or not the patient is breathing spontaneously. After the patient emerges, assisted breathing is performed using a combination of the patient's spontaneous breathing and artificial respiration for a predetermined period of time, and then the ventilator is removed. The timing of removal of this ventilator affects the patient's prognosis. Also, when managing breathing,
The algorithm for processing ventilation mechanical parameters such as lung compliance must be changed depending on the presence or absence of spontaneous breathing. Furthermore, it is important to understand things such as whether the ventilator is properly connected to the patient and whether the artificial respiration and spontaneous breathing are synchronized during the assisted breathing period.

However, in the past, these decisions were made by doctors,
It relies on the nurse's visual observation of the movement of the patient's chest wall. As a result, objective judgments could not be obtained, which could affect the patient's prognosis.

An object of the present invention is to provide a respiratory monitoring device that detects the appearance of spontaneous breathing in a living body connected to a respirator and displays this fact.

a respiratory flow rate needle for measuring the respiratory flow rate of the living body, a signal processing device Vi to which the output signals of the airway pressure needle and the respiratory flow rate needle are inputted, and a display device connected to the signal processing IM. The signal processing device detects the end of the exhalation period from the respiratory flow rate, stores the airway pressure at this time, and uses the stored airway pressure or its average value as a reference value to determine the instantaneous value of the airway pressure. The present invention is characterized in that, when the appearance of spontaneous breathing is detected when the value becomes lower than the reference value by a predetermined amount, a predetermined display is displayed on the display device.

Therefore, according to the present invention, since the appearance of spontaneous breathing can be detected by notifying the doctor, etc., it is extremely effective in determining whether or not to remove the respirator.

The present inventor has developed a respiratory monitoring device that detects the appearance of spontaneous breathing, and a device that detects and displays the appearance of spontaneous breathing when the instantaneous value of the airway pressure exceeds a fixed reference value ( Japanese Patent Application No. 55-10269) and a device for detecting and displaying the appearance of spontaneous breathing when the minimum value of the airway pressure during the inspiratory period becomes lower than the minimum value during the expiratory period 6 (Japanese Patent Application No. 118162-1982) I am proposing something.

Compared to the former method, this invention has the advantage that the reference value is always optimally set, and compared to the latter method, it is also possible to detect the appearance of spontaneous breathing during the exhalation period.

Hereinafter, one embodiment of the respiratory monitoring device according to the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram thereof. One end of the transducer f3 is connected to the tracheal insertion tube 2 inserted into the airway of the patient 1, and the other end of the transducer +3 is connected to the respirator 5 via the swirl tube 4. In this example, the transducer f3 is connected to the tracheal insertion tube 2 to measure the respiratory flow rate and airway pressure of the patient 1 at a position closer to the patient 1.
m has been done. The pressure within the transducer f3 is further supplied to the airway pressure needle 7 via the pipe C. The internal pressure needle 7 is composed of a semiconductor pressure centimeter or the like. The transducer 3 is also provided with an ultrasonic #111b transducer, and the vibrations of this transducer are transmitted via a pipe 8 to a supersonic wave transmission Nj time difference type pneumotachograph 9.

The output electrical signals of the pressure gauge 7 and the flow rate needle 9 are sent to a signal processing device 10.
It is supplied to the inner F1 converter 11. Signal processing ViM
10 further includes a CPU (MicroProcera f) 12
, ROMJJ.

RAMJ 4, video RAMJ 5, bubble memory 16
are also provided, and these are connected via a pass line 11. The signal processing device 10 is processed by the CPU UJJ, and its processing is performed according to a program stored in the ROMJJ. Note that a keyboard 18 is connected to the pass line 17. Further, the output signal of the video RAM 16 is supplied to a video monitor 19 as a display device.

Next, the operation of this embodiment will be explained.

The output signal waveforms of the airway pressure needle 2 and the pneumotachograph 9 are shown in FIG. 2 (mj*(b)).
al).

In (b), the broken line indicates the O level, the area above the broken line indicates the positive level, and the area below the broken line indicates the negative level. The same respiratory flow rate is assumed to be positive during the inhalation period and negative during the expiration period.

Normal human airway pressure reaches its lowest level at the end of the exhalation period and reaches O pressure, but here, the ventilator 5 causes the second factor (
1) is maintained at a certain positive value (hereinafter referred to as PliiliP value) shown by the dotted line. This type of artificial respiration method is
Mely@Jilnd gxplrstoryPress
ure (PBEP) method.

The signal processing device 10 collects the output signals of the airway pressure needle 7 and the respiratory flow needle 9, and simultaneously performs signal processing for detecting the appearance of spontaneous breathing. Here, we will explain this operation and then explain the principle of detecting the appearance of spontaneous breathing. Normally, under artificial respiration using the PGGP method, the lowest value of the airway pressure at the end of the expiratory period is maintained at a positive PEIIP value ζ2, but when the patient's spontaneous breathing appears, at the beginning of the patient's inspiratory period. The airway pressure drops below the PIilliiP value due to expansion of the patient's lungs. Therefore, if it is detected that the airway internal pressure becomes lower than the pggp pressure, it means that the appearance of spontaneous breathing has been detected. Therefore, the CPU 12 first detects the timing of the end of the exhalation period from the respiratory flow rate data, and detects the airway internal pressure at this time as the PBEP pressure. The operation of this task will be explained with reference to the flowchart shown in FIG. This task is carried out by A7. It is started every time a conversion is completed, and the flag is initialized to 1. In a step 301 following the start step 300, respiratory flow data from the pseudo converter 11 is read into the CPU II. Here R
AMJ 4 has breath-grade flow data and airway pressure? It has been updated and stored for the ith time.

Next, in step 302 it is determined whether the flag is greater than one. If the flag is not greater than 1, step JO3 sets a negative respiratory flow rate (e.g. -100c/8).
It is determined whether or not the task has continued for 2001"8. This determination is made based on whether the data read from RAMJ4 represents a flow rate of -100- or less. If it has not continued, this task is executed at step 310. be terminated.

If it continues, the flag is set to 2 in step 304, and then this task ends. The period in which the respiratory flow rate is 200 c/s or less is the expiratory period, and when the expiratory period is detected, the flag is set to 2. When the next A/L) f period ends, step 301 is executed, and step J (if it is determined that the flag is greater than 1 in step 72, it is determined in step 305 whether the respiratory flow rate is smaller than 10°/S. If the respiratory flow rate is smaller than 100/8, the expiratory period Since this may be the end of the period or the rest period, the airway pressure and time are temporarily set in step j06.Then, this task processing ends.

If the respiratory flow rate is greater than 10 (/s) in step 305, the positive respiratory flow rate (100c/8) is increased to 2 in step say.
00 Its is determined whether it has continued. 200”8
If it continues, it means that the Monki period has started,
The airway pressure set in step SOt is stored in step gos as the airway pressure at the end of the exhalation period, that is, the PiitBP pressure. After the airway pressure at the end of the exhalation period is thus stored, the flag is set to 1 again at step 30g and the task ends.

Along with this task, CPUJj (=, in this example, in order to improve the detection accuracy, the stored Piill) F
Average the pressure according to the flowchart shown in Figure 4,
This average pressure is used as a reference pressure for detection.

This task is restarted every time the previous task detects the airway pressure at the end of the exhalation period. Start step 40
In step 401 following 0, the airway pressures stored by the task shown in Figure 3 are averaged, and in step 402 it is determined whether 5 minutes have elapsed since monitoring VIIIi was started. If 5 minutes have not elapsed, this average value is stored as a reference value in step 403, and after -11, this task ends in step 401. In other words, immediately after starting the device, the average value is updated sequentially. 5 minutes after giiWIL starts, step 4
At 04, another timer is started and clocks for 5 minutes. If five minutes have not elapsed, the task ends in step 404.

After 5 minutes have elapsed, the average value for the 5 minutes is stored as a reference value in step 405. Then step 40
After the average value is reset with σ, the task ends in step 401.

In other words! When 5 minutes have passed since the i-position was started, the average value is updated every 5 minutes.

Next, detection of the appearance of spontaneous breathing is performed according to the flowchart shown in FIG. This task is also started every 10th Hatake/C, similar to the exhalation period end detection task.

At the next step 501 after the start step 500, A7.
The airway pressure chimpled by the converter 11 is read. In step 502, the sampled airway pressure is 1
It is determined whether the pressure is 0.5cxH,O pressure lower than the reference value □1♂ obtained by the task shown in Fig. 14. If it is not low, this task ends in step 505, and if it is low, the appearance of spontaneous breathing is detected in step 50S, and in step 504, the data for one breath in which this spontaneous breathing was recognized is distinguished from other data, and the process is performed in step 50S. 505
This task ends. In this way, the appearance of spontaneous breathing is detected.

When the appearance of spontaneous breathing is detected in this way, the airway pressure is displayed on the television monitor 19 as shown in FIG. 6(a) i:
As shown in Figure 6(b), the pressure waveform for the breath is displayed in bold, or it is surrounded by a waveform line segment lower than the pnlp pressure (one point Mm) and a line segment indicating the pigp pressure. By displaying the entire area with brightness modulation, it is possible to visually grasp the appearance of spontaneous breathing. Thereby, it is possible to accurately determine the transition from artificial respiration to auxiliary respiration and the strength of spontaneous respiration, that is, whether or not artificial respiration is necessary. This display is performed on the video monitor 19 in response to instructions from the keyboard 18.

The appearance of spontaneous breathing is shown in Figure 7 (m) and (b).
) d; As shown in Fig. 2, the airway pressure and respiratory flow rate waveforms can be displayed side by side in the same time series, or the airway pressure (Pi and respiratory flow rate ■) can be plotted as a trajectory on the X-T plane as shown in figure s8. In addition, during these displays, in order to distinguish the appearance of spontaneous breathing from others, the brightness may be increased, but the color may be changed.

Furthermore, although the combination of airway pressure and respiratory flow rate is shown, other biological signal waveforms, such as volume curves, glIL slowness curves of oxygen, carbon dioxide, etc., may be combined.

Furthermore, in the flowchart shown in FIG. 3, if the positive and negative respiratory flow rates are reversed, the start point of exhalation can also be detected. If the respiratory period is divided into an expiratory period and an expiratory period, ventilation mechanical parameters are calculated by the following equation using the respiratory flow rate and airway pressure during the inspiratory period.

P --! -f　F　d　t　+　RF　+　P　.

C However, P is the airway pressure (cm Hm Ol-) F is the respiratory flow rate (m?,...) Pa is PI! ilP pressure C is the lung compliance (''/cx H, Oi )R
is airway resistance (tx HaOl//, 1/sec)
The lung pressure and airway resistance determined by this equation are physiologically meaningful in the case of no spontaneous breathing. These ventilation mechanics parameters are stored in the bubble memory 16, and displayed on the monitor 1 as trend graphs as shown in FIGS. 9(a) and 9(b) according to instructions from the keyboard IJ. FIG. 9(1) shows lung compliance, and FIG. 9(b) shows airway resistance. Again, the data can be plotted based on the presence or absence of spontaneous breathing. In other words, when there is no spontaneous breathing.

Or it is plotted as 0. The horizontal axis of these trend graphs indicates time, and data is plotted every 5 minutes.

This makes it possible to accurately determine when to remove the ventilator. In addition, from the display on the 72T, if the spontaneous breathing of the person and the operation of the ventilator are not synchronized after the transition to assisted breathing, the fighting phenomenon can be prevented by adjusting the operation of the ventilator. . In addition, since the reference value for detecting the appearance of spontaneous breathing is determined from the measured value of the patient's airway pressure, the Pl of the artificial respiration articulator! IK
Even if the P value changes, the appearance of spontaneous breathing can be reliably detected.

[Brief explanation of drawings]

Fig. 1 is a block diagram of one embodiment of the respiratory monitoring device according to the present invention, Fig. 2 (b) is a diagram showing an example of the respiratory flow rate waveform and airway pressure waveform, and Figs. 3 to 5 & 82 are the same embodiments. Fq-t yards for explaining example operations, Figures 6 to 9
The figure is a diagram showing an example of a display in the same embodiment. J... Transjugator, 2... Airway pressure needle, 9.
... Respiratory flow rate needle, 1o... Signal processing ms device, 19 river video monitor (display device). Patent Attorney Suzue Shikihiko Figure 2 (a) (b) Figure 3 Figure 4 Figure 5

Claims (1)

[Scope of Claims] α) An airway pressure needle that measures the airway pressure of a living body connected to a ventilator, a pneumotachograph that measures the respiratory flow rate of the living body, and a pneumoflowmeter that measures the respiratory flow rate of the living body to which a ventilator is connected; A signal processing device to which an output signal is given as an input, and this signal path m\
and a display device connected to Il[, the signal processing device detects the end of the exhalation period from the respiratory flow rate, memorizes the airway pressure at this time, and records the memorized airway pressure or its average. When the appearance of spontaneous breathing is detected when the instantaneous value of the airway internal pressure becomes lower than the reference value by a preset value, the display device is configured to display a predetermined display. A breathing monitoring device featuring: (2) The signal path [gi] is configured to detect the appearance of spontaneous breathing when the instantaneous value of the airway pressure within a certain period of time from the start of the expiration period is less than the reference value by a predetermined amount. 112. A respiratory monitoring device according to claim 111. 0) The signal processing device is configured to cause the display device to display airway internal pressure data and respiratory flow rate data, and to change the display mode of these display data when the appearance of spontaneous breathing is detected. A respiratory monitoring device according to claim 1, characterized in that: (4) The signal processing Sat is configured to display airway internal pressure data and respiratory flow rate data in the same time series on a display device, claim 3.
Respiratory monitoring device as described in Section. (5) The signal processing device is configured to cause the display device to display airway pressure data and respiratory flow rate data as trajectories on an X-Y plane with the airway pressure value and respiratory flow rate values as axes, respectively. A respiratory monitoring device according to claim 3, characterized in that: (6) The signal processing m*ai is characterized in that it is configured to display airway internal pressure data and respiratory flow rate data as a trend graph of ventilation mechanical parameters determined from these data on the display VIi1t. Respiratory monitoring according to claim 3 *1゜