JP3767329B2 - Computer-readable recording medium on which high-frequency ventilator and its operation control program are recorded - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high-frequency ventilator and a computer-readable recording medium that records an operation control program thereof.
[0002]
[Prior art]
A conventional high frequency ventilator 200 is shown in FIG. The high-frequency ventilator 200 includes an inhalation introduction part 62 that supplies inhalation containing oxygen to the patient X, a patient side path 60 that guides inhalation from the inhalation introduction part 62 to the patient X, and the patient side path. 60, an oscillating air pressure urging unit 50 that urges an oscillating air pressure having a cycle shorter than the breathing cycle of the patient X to an inhalation flowing through the air 60, and an exhaust path for exhausting exhaled air containing carbon dioxide from the patient X to the atmosphere ( A discharge pipe 604), a flow rate adjustment valve 607 as an internal pressure adjustment section that adjusts an average airway pressure from the patient-side path 60 to the discharge pipe 604, and a controller 201 that controls the operation of each part of the ventilator 200. .
[0003]
The principle of oxygen supply of the high-frequency ventilator 200 will be described. First, when high-frequency oscillating air pressure is applied to the inspiration supplied to the patient X, the inspiration including the carbon dioxide in the lungs of the patient X (hereinafter referred to as exhalation) is caused by the pressure amplitude of the inspiration. A small volume of ventilation (convective gas exchange) occurs. That is, due to the effect of the diffusion movement by the vibration of the inspiration, the inhalation enters the lung and the exhalation in the lung is led out of the lung (patient's mouth). The subsequent inspiration performs the above-described ventilation and also has an action of sending the exhaled air derived from the lungs to the exhaust port side. This makes it possible to always maintain a constant oxygen concentration in the patient's lungs.
[0004]
In such a conventional high-frequency ventilator 200, the vibration frequency (generally 3 to 15 [Hz], hereinafter referred to as a frequency of high-frequency vibration air pressure arbitrarily selected by the doctor according to the state of the patient (the subject to whom the artificial respiration is performed). This vibration frequency is described as the ventilation frequency), and the average airway pressure is 5-15 [cmH₂O] (490-1470 [Pa]) is set in the range, and artificial respiration is performed.
[0005]
The ventilation frequency is determined according to the weight of the patient X in the initial stage. That is, the vibration of the patient X and the inhalation vibration is resonated to enhance the diffusion effect of the inspiration, and the frequency is set so that the ventilation in the lung can be efficiently performed. In general, when the subject of artificial respiration is a newborn, the ventilation frequency is set to about 13 to 15 [Hz], and from 3 to 10 [Hz] for a dwarf to an adult.
[0006]
Furthermore, high-frequency ventilation requires that the average airway pressure of inspiration be maintained at the pressure desired by the doctor while oscillating the inspiration at the above ventilation frequency. Here, a conventional method for detecting the average airway pressure will be described.
[0007]
The controller 201 samples one waveform of a detection signal consisting of a vibration waveform from a pressure sensor 93 provided near the mouth of the patient X at a predetermined time interval, averages each sampling data, and averages the one waveform. Calculate the pressure. Specifically, first, a detection signal for one waveform corresponding to one cycle is sampled at a time interval that divides the signal into n equal parts, and the value from the first sampling data to the nth sampling data is added and divided by n. Calculate the average pressure Pa of the minute.
[0008]
Pa = (P1 + P2 + P3 + ... + Pn) / n (1)
[0009]
When the average pressure Pa for m periods is calculated based on the above equation (1), the average value is further calculated from the m average pressure Pa. Then, since the detection signal is continuously input from the pressure sensor 93, the average pressure Pa for one cycle is sequentially calculated, and the latest Pa is added every time and the oldest Pa is rounded down to m pieces. The average airway pressure Pca is continuously calculated from the average pressure Pa by the moving average method (the following equation (2)).
[0010]
Pca = (Pca1 + Pca2 + Pca3 + ... + Pcam) / m (2)
[0011]
The controller 201 performs operation control to maintain the average airway pressure Pca, which is constantly updated, at a predetermined pressure. The average airway pressure Pca can be freely changed by adjusting the valve opening degree of the flow rate adjusting valve 607 provided at the end of the discharge pipe 604.
[0012]
Therefore, the average airway pressure Pca calculated by the above equation (2) is compared with the target average airway pressure Pg desired by the doctor, and if Pg> Pca, the opening of the flow control valve 607 is reduced and the pipe pressure is reduced. If Pg <Pca, the opening control of the flow control valve 607 is increased to control the operation to reduce the pressure in the pipe.
[0013]
By the way, the conventional high-frequency ventilator is often used for newborns, and the treatment with high-frequency ventilation for newborns is frequently used in the vicinity of 15 [Hz]. In order to obtain the characteristic information of the vibration waveform of 15 [Hz], if the pressure is sampled every 6 [msec], 11 sampling data per waveform can be obtained. FIG. 18 is a conceptual diagram for obtaining an average airway pressure Pca of inspiration at a ventilation frequency of 15 [Hz]. First, the average pressure Pa obtained at a sampling interval of 6 [msec] is shown in the following equation (3).
[0014]
Pa = (P1 + P2 + ... + P11) / 11 (3)
[0015]
By calculating the average pressure Pa for 10 waveforms by the above equation (3) and calculating the moving average pressure Pca therefrom, the operation control of the flow rate adjustment valve 607 (average airway pressure adjustment) is performed. As described above, the average airway pressure Pca can be set to the target value for high-frequency artificial respiration of a newborn infant that is almost fixed at a ventilation frequency of 15 [Hz].
[0016]
[Problems to be solved by the invention]
However, when high-frequency artificial respiration is performed for an adult, a low frequency of 3 to 10 [Hz] having a longer wavelength than 13 to 15 [Hz] used for a newborn is used. For example, when the ventilation frequency is set to 5 [Hz], a waiting time for sampling of 200 [msec] is required for calculating the average pressure Pa of one waveform. This standby time corresponds to the time for three waveforms in the case of 15 [Hz] described above.
[0017]
Further, if the moving average of 10 waveforms is taken as in the case described above, 200 × 10 = 2000 [msec] = 2 [sec] is required while obtaining the first moving average. This 2 [sec] is the time required for data sampling and calculation of the average airway pressure Pca, and during this time, data processing is not performed, so that the operation control of the flow rate adjustment valve 607 is not performed at all.
[0018]
The next average pressure Pa is obtained 200 [msec] after the latest waveform data is sampled. Even if the flow control valve 607 is immediately controlled with respect to the previous average airway pressure Pca. As a result, it can be known after 200 [msec] how much the average airway pressure Pca in the patient circuit has changed. In particular, in the case of air, it is a compressible fluid and has air inertia. As a result of controlling the flow rate adjustment valve 607 based on the average airway pressure Pca, the actual phenomenon of the pressure increase or decrease in the patient circuit immediately follows. It does not always appear in the pressure waveform, but may appear in the next pressure waveform or the next pressure waveform.
[0019]
In the case of the control of the ventilation frequency 15 [Hz] described above, even if the air to be controlled is a compressible fluid or the influence of air inertia, a short cycle for each waveform (66 [msec]) Since the average airway pressure Pca is obtained and the feedback control is performed with a short control interval, it is possible to control the flow rate adjusting valve 607 in small increments, and it is a target without being affected by the time constant of the air pressure change to be controlled. It was possible to stably control the average airway pressure.
[0020]
However, when the period of one waveform is as long as 200 [msec] like the ventilation frequency 5 [Hz], the interval of feedback control based on the moving average becomes long. Even if the average airway pressure Pca obtained by moving average from the detected pressure is calculated, and the flow rate control valve 607 is controlled so as to reach the target average airway pressure, the time taken for one waveform of pressure data is 200 [msec]. Therefore, the flow rate adjustment valve 607 cannot be controlled every minute. Since the opening / closing control of the flow control valve 607 can be performed only in such a long cycle, the average airway pressure Pca could not be stably maintained.
[0021]
OBJECT OF THE INVENTION
The present invention improves the inconvenience of such a conventional example, and even when the ventilation frequency is low, the computer can read a high-frequency ventilator that can satisfactorily control the average airway pressure and its operation control program. The object is to provide a recording medium.
[0022]
[Means for Solving the Problems]
  BookinventionHigh frequency ventilatorIs an inhalation intake section that supplies inhalation containing oxygen, a patient-side path that guides the inhalation to the patient, an oscillating air pressure urging section that urges a high frequency oscillating air pressure to the inhalation to the patient, and a discharge from the patient. A discharge path that discharges the exhaled breath into the atmosphere, an internal pressure adjustment unit that adjusts the average airway internal pressure of the intake air supplied to the patient, a pressure sensor that detects the pressure of the intake air near the patient, and an internal pressure based on the output of the pressure sensor And a controller for controlling the operation of the adjusting unit.Ru.
[0023]
  The controller includes a sampling unit that sequentially extracts the detected pressure from the output of the pressure sensor at a predetermined sampling interval, and three detected pressures P (1), P (2), and P (3) in the order of extraction. Memorize and update the detected pressure P (1), P (2), P (3) each time a new detected pressure is extracted, and three detected pressures P (1), P (2), P According to the pressure change pattern of (3),
  a is a predetermined pressure difference, and K, L, M, N, and O are predetermined coefficients.,
  The pressure change pattern is P (1) ≦ P (2) < P (3) and P (1) − P (2) + A ≧ P (3) − P (2) In the case of Ps The formula Ps = P (2) + K ・ ( P (3) − P (2) ),
  The pressure change pattern is P (1) > P (2) > P (3) In the case of Ps The formula Ps = P (2) − {P (1) − P (2) + L ・ ( P (2) − P (3) ) } Calculated from,
  The pressure change pattern is P (1) < P (2) and P (2) > P (3) In the case of Ps The formula Ps = P (2) -M ・ ( P (2) − P (1) ) -N ・ ( P (2) − P (3) ),
  The pressure change pattern is P (1) > P (2) and P (2) < P (3) In the case of Ps The formula Ps ＝ O ・ ( P (1) − P (2) ) + P (2) Calculated from,
  Any of the calculated correction pressures Ps An expression containing Ph = ( P (2) + Ps ) / The mean airway pressure based on 2 Ph While calculating,
  The detected pressure when the pressure change pattern does not correspond to any case P (3) The average airway pressure as it is Ph WhenAnd an update unit that writes the calculated Ph into the memory as the detected pressure P (3) when the average airway pressure Ph is calculated. The present invention intends to solve the above-mentioned problems by such a configuration.
[0024]
The above-mentioned average airway pressure refers to an average pressure per one cycle of the intake air supplied by energizing the oscillating air pressure.
[0025]
  Further, instead of the controller, the three detected pressures P (1), P (2), P (3) Depending on the pressure change pattern of
  a is a predetermined pressure difference, L, M, N, O, Q are predetermined coefficients, and H is a function of the ventilation volume of one cycle of the oscillating air pressure urging unit.,
  The pressure change pattern is P (1) ≦ P (2) < P (3) and P (1) − P (2) + A ≧ P (3) − P (2) In the case of Ps The formula Ps = P (2) + Q ・ H ・ ( P (3) − P (2) ),
  The pressure change pattern is P (1) > P (2) > P (3) In the case of Ps The formula Ps = P (2) − {P (1) − P (2) + L ・ ( P (2) − P (3) ) } Calculated from,
  The pressure change pattern is P (1) < P (2) and P (2) > P (3) In the case of Ps The formula Ps = P (2) -M ・ ( P (2) − P (1) ) -N ・ ( P (2) − P (3) ),
  The pressure change pattern is P (1) > P (2) and P (2) < P (3) In the case of Ps The formula Ps ＝ O ・ ( P (1) − P (2) ) + P (2) Calculated from,
  Any of the calculated correction pressures Ps An expression containing Ph = ( P (2) + Ps ) / The mean airway pressure based on 2 Ph While calculating,
  The detected pressure when the pressure change pattern does not correspond to any case P (3) The average airway pressure as it is Ph And the average airway pressure Ph Is calculated Ph The detected pressure P (3) A controller having an update unit for writing to the memory may be applied..
  Here, Q is a predetermined coefficient, and H is a function of the ventilation amount in one cycle of the oscillating air pressure urging unit. Note that the function of the ventilation amount of one cycle of the oscillating air pressure urging unit mentioned here may be the ventilation amount per cycle of the oscillating air pressure itself, and other parameters (for example, for example, determining the ventilation amount) The output of the drive source of the oscillating air pressure urging unit may be used. As for these values, it is conceivable that numerical values set and input during operation of a high-frequency ventilator are used for calculation as they are..
[0026]
  The controller has an average airway pressure Ph An internal pressure control unit for controlling the operation of the internal pressure adjustment unit is added as a configuration so that becomes a target value. Then, the internal pressure control unit calculates the average airway pressure obtained by any of these calculations. Ph Control of the internal pressure adjustment unit so that becomes the target value.
[0027]
  The controller adds a mean processing unit that outputs a value to the memory as a detected pressure while averaging a predetermined number of detected pressures extracted from the sampling unit, and the arithmetic unit is averaged. The average airway pressure is calculated based on the detected pressure..
[0031]
  The computer-readable recording medium of the present invention isA computer-readable storage medium storing an operation control program for realizing the configuration and functions of the controller of the above-described high-frequency ventilator using a computerIs.
[0032]
  That is, thisThe operation control program stored in the computer-readable recording medium is,
  A sampling unit that sequentially extracts the detected pressure at predetermined sampling intervals from the output of the pressure sensor that is continuously input;
  Three detected pressures P (1), P (2), P (3) are stored in the order of extraction, and each time a new detected pressure is extracted, the detected pressures P (1), P (2), Memory to update P (3),
  Pattern of pressure change of the three detected pressures P (1), P (2), P (3) extracted in orderInAccording to
  a is a predetermined pressure difference and K, L, M, N, and O are predetermined coefficients.,
  The pressure change pattern is P (1) ≦ P (2) < P (3) and P (1) − P (2) + A ≧ P (3) − P (2) In the case of Ps The formula Ps = P (2) + K ・ ( P (3) − P (2) ),
  The pressure change pattern is P (1) > P (2) > P (3) In the case of Ps The formula Ps = P (2) − {P (1) − P (2) + L ・ ( P (2) − P (3) ) } Calculated from,
  The pressure change pattern is P (1) < P (2) and P (2) > P (3) In the case of Ps The formula Ps = P (2) -M ・ ( P (2) − P (1) ) -N ・ ( P (2) − P (3) ),
  The pressure change pattern is P (1) > P (2) and P (2) < P (3) In the case of Ps The formula Ps ＝ O ・ ( P (1) − P (2) ) + P (2) Calculated from,
  Any of the calculated correction pressures Ps An expression containing Ph = ( P (2) + Ps ) / The mean airway pressure based on 2 Ph While calculating,
  The detected pressure when the pressure change pattern does not correspond to any case P (3) The average airway pressure as it is Ph WhenComputing unit,
  When the average airway pressure Ph is calculated, each component including an updating unit that writes the Ph into the memory as the detected pressure P (3) is caused to function on a computer.
[0033]
  The operation control program stored in the computer-readable recording medium is,
  A sampling unit that sequentially extracts detected pressures at predetermined sampling intervals from the output of the pressure sensor that is continuously input,
  Three detected pressures in the order of extraction P (1), P (2), P (3) And the detected pressure every time a new detected pressure is extracted. P (1), P (2), P (3) Update memory,
  The three detected pressures extracted in order P (1), P (2), P (3) Depending on the pressure change pattern,
  a is a predetermined pressure difference, L, M, N, O, Q are predetermined coefficients, and H is a function of the ventilation volume of one cycle of the oscillating air pressure urging unit.,
  The pressure change pattern is P (1) ≦ P (2) < P (3) and P (1) − P (2) + A ≧ P (3) − P (2) In the case of Ps The formula Ps = P (2) + Q ・ H ・ ( P (3) − P (2) ),
  The pressure change pattern is P (1) > P (2) > P (3) In the case of Ps The formula Ps = P (2) − {P (1) − P (2) + L ・ ( P (2) − P (3) ) } Calculated from,
  The pressure change pattern is P (1) < P (2) and P (2) > P (3) In the case of Ps The formula Ps = P (2) -M ・ ( P (2) − P (1) ) -N ・ ( P (2) − P (3) ),
  The pressure change pattern is P (1) > P (2) and P (2) < P (3) In the case of Ps The formula Ps ＝ O ・ ( P (1) − P (2) ) + P (2) Calculated from,
  Any of the calculated correction pressures Ps An expression containing Ph = ( P (2) + Ps ) / The mean airway pressure based on 2 Ph While calculating,
  The detected pressure when the pressure change pattern does not correspond to any case P (3) The average airway pressure as it is Ph Arithmetic unit,
  And this average airway pressure Ph Is calculated Ph The detected pressure P (3) As an update unit for writing to the memory, the computer may function as.
  Note that the function of the ventilation amount of one cycle of the oscillating air pressure urging unit mentioned here may be the ventilation amount per cycle of the oscillating air pressure itself, and other parameters (for example, for example, determining the ventilation amount) The output of the drive source of the oscillating air pressure urging unit may be used. As for these values, it is conceivable that numerical values set and input during operation of a high-frequency ventilator are used for calculation as they are..
[0034]
  In addition, the motion control program recorded on the recording medium performs the calculated average airway pressure. Ph A determination unit for determining the comparison between a predetermined target value and a preset target value, and when the determination result of the determination unit assumes that the average airway pressure is high, an average airway pressure reduction command is output to the internal pressure adjustment unit, and the average airway pressure Drive command output unit that outputs an average airway pressure increase command to the internal pressure control unit when the pressure is low, causes the computer to newly function.
[0035]
  Further, the operation control program recorded on the recording medium averages each time a predetermined number of detected pressures are extracted from the sampling unit and sequentially outputs the value as a detected pressure to the arithmetic unit, In addition to causing the computer to newly function, the above-described calculation unit causes the computer to function so as to calculate the average airway pressure based on the averaged detected pressure..
[0038]
DETAILED DESCRIPTION OF THE INVENTION
[First embodiment]
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing a configuration of a high-frequency ventilator 12 according to this embodiment.
[0039]
The high-frequency ventilator 12 includes an inhalation introduction part 62 that supplies inhalation containing oxygen to the patient X, a patient side path 60 that guides inhalation from the inhalation introduction part 62 to the patient X, and the patient side path. 60, an oscillating air pressure urging unit 50 that urges an oscillating air pressure having a cycle shorter than the breathing cycle of the patient X to an inhalation flowing through the air 60, and an exhaust path for exhausting exhaled air containing carbon dioxide from the patient X to the atmosphere ( A discharge pipe 604), a flow rate adjusting valve 607 as an internal pressure adjusting unit that adjusts the average airway pressure of the patient side path 60 and the discharge pipe 604 as the discharge path, and a pressure sensor 93 that detects the internal pressure of the patient side path 60. And a controller 40 that controls the operation of each part of the ventilator 12.
[0040]
Each part is described in detail below.
[0041]
(Intake inlet)
The intake air introduction unit 62 is connected to oxygen and air supply sources 621a and 621b, and includes a blender 621 as a first adjusting means for mixing them, and a humidifier 622 for humidifying the air sent from the blender 621. Has been.
[0042]
The oxygen and air supply sources 621a and 621b are constituted by cylinders in which they are sealed, and these supply valves provided in hospital facilities, respectively. These supply sources 621a and 621b always supply oxygen and air to the blender side at a constant pressure.
[0043]
The blender 621 has a flow rate adjustable valve (not shown) at a connection portion with each of the supply sources 621a and 621b, and the oxygen concentration of the intake air can be freely set by adjusting these valves. Further, the blender 621 includes an output valve (not shown) that can adjust the flow rate of the intake air to the humidifier 622 side. The oxygen concentration setting and flow rate setting of the intake air are freely performed in response to an operation signal from the controller 40.
[0044]
The humidifier 622 is connected to an intake pipe 623 that supplies humidified inhalation to the patient X. The intake pipe 623 branches in the middle, and one end side communicates with a pressurized chamber 563 of a diaphragm mechanism 56 described later, and the other end side is connected to a three-way branch pipe 170 described later.
[0045]
(Vibration air pressure energizing part)
The oscillating air pressure urging unit 50 alternately selects a blower 52 as an amplitude adjusting unit that simultaneously generates both positive and negative air pressures, and a positive pressure or negative pressure generated by the blower 52, and generates a predetermined oscillating air pressure. A rotary valve mechanism 54 serving as a frequency adjusting unit that converts to a diaphragm, and a diaphragm that is actuated by the oscillating air pressure from the rotary valve mechanism 54 and that urges the oscillating air pressure to the inhalation supplied from the inhalation introduction unit 62 to the patient X The structure including the mechanism 56 is adopted.
[0046]
The blower 52 described above generates positive pressure and negative pressure at the same time by taking air into and sending out the air. An air intake port of the blower 52 is connected to a negative pressure port 542 of a rotary valve mechanism 54 described later, and an air delivery port is connected to a positive pressure port 541.
[0047]
The blower 52 has a fan and a motor that rotationally drives the fan. This motor is provided with an inverter, and its output is controlled by the controller 40 to set the amount of air sent and the magnitude (pressure amplitude) of the vibration air pressure Apn.
[0048]
The rotary valve mechanism 54 includes a positive pressure port 541 to which a positive pressure is input from the blower 52, a negative pressure port 542 to which a negative pressure is urged from the blower 52, an output port 543 that outputs vibration air pressure, and its rotation. Thus, the output port 543 is composed of a rotary valve 544 that alternately connects the positive pressure port 541 and the negative pressure port 542, and a drive unit 545 that rotates the rotary valve 544.
[0049]
The drive unit 545 includes a motor and a speed reducer (not shown), and rotates the rotary valve 544 at a rotation speed designated by the controller 40. Each time the rotary valve 544 rotates, only the port 541 and the port 543 are communicated once, and then only the port 542 and the port 543 are communicated once. Accordingly, the oscillating air pressure Apn having the oscillating frequency proportional to the rotational speed of the drive unit 545 is applied to the supplied intake air. The controller 40 controls the vibration frequency (ventilation frequency) of the oscillating air pressure Apn by controlling the rotational speed of the drive unit 545.
[0050]
In addition, as described above, the controller 40 also controls the amount of air sent from the blower 52. By setting the amount of air sent according to the vibration frequency, the controller 40 performs one-time ventilation in the oscillating air pressure urging unit. The amount (amplitude amount per vibration period of the vibration air pressure Apn) can be set freely.
[0051]
The port 543 is connected to a vibration air pressure tube 546 that transmits the vibration air pressure Apn to the diaphragm mechanism 56.
[0052]
The diaphragm mechanism 56 includes a pressurizing chamber 562 and a pressurized chamber 563, and a diaphragm 561 formed of a stretchable film member that partitions the pressurized chamber 562 and the pressurized chamber 563. . The pressurizing chamber 562 is connected to the oscillating pneumatic tube 546. The pressurizing chamber 562 is connected to the output port 543 of the rotary valve 54, and the pressurized chamber 563 is connected to the intake pipe 623. With this structure, the oscillating air pressure formed by the rotary valve 54 is urged by the intake air flowing through the intake pipe 623 via the diaphragm 561. The diaphragm mechanism 56 blocks gas flow between the oscillating air pressure urging unit 50 and the patient X, thereby preventing mutual contamination.
[0053]
(Patient route)
Further, the high-frequency ventilator 12 includes a three-way branch pipe 170 on the downstream side of the intake pipe 623, and the three-way branch pipe 170 further branches the downstream side into the patient X side and the discharge path side. The three-way branch pipe 170 includes three pipe lines, a patient-side pipe line 171, an oxygen supply source-side pipe line 172, and an exhalation-discharge side pipe line 173, all of which are in communication with each other. The oxygen supply source side pipe line 172 is connected to the intake pipe 623. The patient-side conduit 171 is formed with a mounted portion 171a to which an endotracheal insertion tube 81 extending into the lungs of the patient X is freely mounted at the patient-side end.
[0054]
The three-way branch pipe 170, the intake pipe 623, and the endotracheal insertion pipe 81 constitute a patient-side path 60. In addition, a patient-side pressure sensor 93 that detects an average airway pressure is provided in the patient-side conduit 171, and the detected pressure is output to the controller 40.
[0055]
In the endotracheal insertion tube 81, the proximal end portion is attached to the above-described attachment portion 171a, and the distal end portion is inserted into the trachea from the mouth of the patient X. Such a tip is inserted to the branch point (first branch) where the trachea branches into the left and right bronchi. Accordingly, the endotracheal insertion tube 81 is set to a length that can sufficiently reach from the mouth of the patient X to the first branch, and of course, an outer diameter that can be inserted into the trachea is used.
[0056]
For example, in the case of an adult male, the length from the mouth to the first branch is about 22 to 26 [cm], and the length from the patient side conduit 171 of the three-way branch pipe 170 to the mouth is +3 to 5 [cm]. Therefore, the total length of the endotracheal tube 81 may be about 25 to 31 [cm], and is set to 30 [cm] in the present embodiment. The endotracheal tube 81 has four inner diameters of 3 [mm], 5 [mm], 6 [mm], and 8 [mm] depending on the inner diameter of the patient's trachea. Is selected and used. In general, when a normal adult is a subject, an endotracheal tube 81 having an inner diameter of about 8 [mm] is used.
[0057]
Further, the endotracheal tube 81 is replaceable and detachable from the mounted portion 171a. Therefore, after being used for artificial respiration, it is removed and discarded or sanitized and reused.
[0058]
(Discharge route)
Further, the exhalation discharge side pipe line 173 of the three-way branch pipe 170 is connected to one end portion of a discharge pipe 604 as a discharge path, and a flow rate adjusting valve 607 as an internal pressure adjusting section is connected to the other end portion of the discharge pipe 604. Has been. The exhaust pipe 604 and the flow control valve 607 serve as a passage for exhaled air containing carbon dioxide emitted from the lungs of the patient X.
[0059]
FIG. 2 is an enlarged view showing a part of the periphery of the flow rate adjusting valve 607 by cutting away. As shown in this figure, the flow rate adjusting valve 607 includes a housing 607a, an exhaust port 607b, a flow control valve (control silicon sheet) 607c, and a reciprocation that moves the transfer valve 607c forward and backward along a certain direction. And a solenoid 607d as an urging mechanism.
[0060]
The solenoid 607d moves the moving valve 607c by a moving amount corresponding to a control signal from the controller 40, and thereby the exhalation discharge amount of the flow rate adjusting valve 607 can be freely adjusted. Since the patient-side path 60 communicates with the exhaust pipe 604, the internal pressure of the patient-side path 60 as well as the exhaust pipe 604 can be adjusted by adjusting the exhalation discharge amount.
[0061]
(controller)
Next, the controller 40 will be described with reference to FIGS. FIG. 3 is a block diagram showing a control system of the high frequency ventilator 12. The controller 40 is composed of an arithmetic unit including a CPU, a ROM, and an A / D converter, and a program for executing operation control of the high-frequency ventilator 12 described later is input.
[0062]
The controller 40 is provided with an operation panel 43 for a doctor (an operator of the high-frequency ventilator 12) to input operation conditions for each part of the high-frequency ventilator 12, and a display unit 44 for displaying the input operation conditions. ing.
[0063]
The above-described operation panel 43 allows the doctor who is the operator of the high-frequency ventilator 12 to perform a tidal volume on the lungs of the patient X, a vibration frequency of the oscillating air pressure (hereinafter referred to as “ventilation frequency”), a supply amount of inspiration, For example, the input means includes a keyboard for inputting the average airway pressure in the patient-side path, the diameter of the selected endotracheal tube 81 and the oxygen concentration of inspiration.
[0064]
The display unit 44 is a display unit made of, for example, a liquid crystal panel, and all the operation conditions input to the receiving unit 41 under the control of the operation control unit 49 are displayed on the display unit 44.
[0065]
The controller 40 receives an operation condition setting input from the operation panel 43, and the blower 52 and the rotary valve 54 of the oscillating air pressure urging unit 50 based on the input values input to the reception unit 41. And an operation control unit 49 that performs operation control on the intake air introduction unit 62.
[0066]
All of these operation conditions input from the operation panel 43 are stored in the reception unit 41. The receiving unit 41 is a memory that temporarily stores data, and when each of the operation conditions is newly input, the operation condition that has been stored is overwritten and updated.
[0067]
The operation control unit 49 refers to the oxygen concentration of the intake air stored in the reception unit 41, and performs operation control to open the valves on the supply sources 621a and 621b of the blender 621 of the intake air introduction unit 62 at a predetermined opening degree. Do. At the same time, with reference to the intake air supply amount of the reception unit 41, operation control is performed to open the output valve of the blender 621 of the intake air introduction unit 62 at a predetermined opening.
[0068]
Further, the operation control unit 49 refers to the ventilation frequency stored in the reception unit 41 and adjusts the rotation speed so that the drive unit 545 of the rotary valve 54 of the oscillating air pressure energizing unit 50 has the stored ventilation frequency. Perform motion control. Further, the output (drive output) of the drive motor of the blower 52 that determines the tidal volume per cycle of the oscillating air pressure urging unit 50 from the tidal volume with respect to the patient's lung stored in the reception unit 41 is determined. The operation control is performed.
[0069]
In addition, the controller 40 sequentially extracts the detected pressure at predetermined sampling intervals from the output of the patient-side pressure sensor 93 that is continuously input, and the sampled data of each detected pressure. A memory 81 that temporarily stores data, an average processing unit 82 that averages them every time 10 pieces of detected pressure data extracted from the sampling unit 80 are accumulated, and sequentially outputs them to the memory 81, and is averaged in order. A calculation unit 83 that calculates an average airway pressure Ph that is specific to the pressure change patterns of the three detected pressures P (1), P (2), and P (3), and the average airway pressure Ph is a target value. Thus, the internal pressure control unit 84 that controls the operation of the flow rate adjustment valve 607 is provided.
[0070]
Each part will be described. First, the sampling unit 80 has an A / D conversion function for converting an analog output from the patient-side pressure sensor 93 into a digital output having a sampling interval of 1 [msec].
[0071]
The memory 81 has a storage area for output of at least 10 [msec] from the sampling unit 80 (actually set larger) and a storage area for storing at least three average pressures calculated by the average processing unit 82. is doing.
[0072]
The average processing unit 82 calculates an average value of the values every time 10 outputs of the sampling unit 80 are accumulated in the memory 81, and newly writes the value in the memory 81. The calculated detected pressures are stored in the memory 81 with numbers P (1), P (2), and P (3) in the order of detection. Each time a new average is calculated, the new average is P (3), the original P (3) is P (2), and the original P (2) is P (1 ) And the original P (1) is deleted from the memory 81.
[0073]
The calculation unit 83 responds to the pressure change pattern of the detected pressures P (1), P (2), and P (3) every time P (1), P (2), and P (3) are updated. Then, the average airway pressure Ph is calculated from a calculation formula using P (1), P (2), and P (3) set individually as variables. The internal pressure control unit 84 regards the calculated predictive average airway pressure Ph as the current average airway pressure, and controls the operation of the flow rate adjustment valve 607 so as to approach the target average airway pressure.
[0074]
The calculation unit 83 includes a comparison unit 85 that compares the detected pressures P (1), P (2), and P (3), and P (1), P (2 ), P (3) as a function, an average airway pressure calculator 86 for calculating the average airway pressure Ph by selecting a calculation formula, and an updater for updating the value of P (3) in the memory 81 according to the calculation result 87.
[0075]
That is, in the comparison unit 85, the pattern of the pressure change of each detected pressure P (1), P (2), P (3) is [A]: P (1) ≦ P (2) <P (3) and P When (1)-P (2) + a ≥ P (3)-P (2), [B]: P (1)> P (2)> P (3), [C]: P (1 ) <P (2) and P (2)> P (3), [D]: P (1)> P (2) and P (2) <P (3), [E]: above Classify into 5 patterns when none of them apply.
[0076]
Here, the principle of performing the above-described calculation processing in the calculation unit 83 will be described in more detail based on FIG. 4 and FIG. FIG. 4 is a diagram showing a pressure change of an average value of detected pressures sequentially calculated. FIG. 4 (A) shows a pattern [A], and FIG. 4 (B) shows a pattern [B]. FIG. 5C shows the pattern [C], and FIG. 5D shows the pattern [D]. A dotted line γ in each of FIGS. 4 and 5 indicates a true average value in one cycle. The symbol α indicates the pressure difference between P (1) and P (2) (α> 0), and the symbol β indicates the pressure difference between P (2) and P (3) (β> 0).
[0077]
The pressure detected by the patient-side pressure sensor 93 generally draws a sin curve since the inspiratory air is urged by the oscillating air pressure urging unit 50 to vibrate at the preset ventilation frequency.
[0078]
[A]: P (1) ≦ P (2) <P (3) and P (1) −P (2) + a ≧ P (3) −P (2) corresponds to the pattern shown in FIG. As shown in A), it is considered that the sine wave is rising. Therefore, the calculation formula of the correction pressure Ps is set to the following formula (4) and the average airway pressure Ph is set to the following formula (5) so as to approach the true average value γ.
[0079]
Ps = P (2) + K.beta. = P (2) + K. (P (3) -P (2)) (4)
[0080]
Ph = (P (2) + Ps) / 2 (5)
[0081]
In this embodiment, the constant a = 1 [cmH₂O] (98 [Pa]) and the coefficient K = 0.03 to 0.33.
[0082]
[B]: P (1)> P (2)> P (3) corresponds to the pattern when the sine wave is falling as shown in FIG. 4B. Therefore, the calculation formula of the correction pressure Ps is set to the following formula (6) and the average airway pressure Ph is set to the following formula (7) so as to approach the true average value γ.
[0083]
Ps = P (2) − (α + L · β) = P (2) − {P (1) −P (2) + L · (P (2) −P (3))} (6)
[0084]
Ph = (P (2) + Ps) / 2 (7)
[0085]
In this embodiment, the coefficient L is set to 0.03 to 0.1.
[0086]
[C]: P (1) <P (2) and P (2)> P (3) corresponds to the pattern, as shown in FIG. This is considered to be when there is a sudden drop-off suddenly for some reason during the sin wave. Therefore, the formula for calculating the corrected pressure Ps is set to the following formula (8) and the average airway pressure Ph is set to the following formula (9) so as to approach the true average value γ.
[0087]
Ps = P (2) -M.alpha.-N.beta. = P (2) -M. (P (2) -P (1))-N. (P (2) -P (3)) (8) )
[0088]
Ph = (P (2) + Ps) / 2 (9)
[0089]
In this embodiment, the coefficient M is set to 0.3 to 0.7 and the coefficient N is set to 0.2 to 0.3.
[0090]
[D] The pattern of P (1)> P (2) and P (2) <P (3) corresponds to the pattern of decreasing once and then increasing as shown in FIG. 5 (B). This is considered to be when a sudden rise in the spot occurs due to some factor in the middle of the sin wave. Therefore, the calculation formula of the correction pressure Ps is set to the following formula (10) and the average airway pressure Ph is set to the following formula (11) so as to approach the true average value γ.
[0091]
Ps = P (2) + O.α = P (2) + O. (P (1) −P (2)) (10)
[0092]
Ph = (P (2) + Ps) / 2 (11)
[0093]
In this embodiment, the coefficient O is set to 0.2 to 0.5.
[0094]
[E]: If none of the above applies, that is, if none of [A] to [D], the detected pressure P (3) is output as the average airway pressure Ph as it is. In any case, when the average airway pressure Ph is calculated, the average airway pressure calculation unit 86 outputs it to the updating unit 87 and the internal pressure control unit 84.
[0095]
The predetermined pressure difference a and the coefficients K, L, M, N, and O described above are the usage conditions (ventilation frequency, tidal volume, inspiratory supply amount, etc.) and the dimensions (air volume) of each part of the high-frequency ventilator. Therefore, it is desirable to obtain by simulation or a test in advance.
[0096]
Further, when the average airway pressure calculating unit 86 calculates the average airway pressure Ph, the updating unit 87 updates the value of the detected pressure P (3) in the memory 81 to the value of the calculated average airway pressure Ph. Such an update is performed in accordance with the timing before the average value of the detected pressure is newly calculated by the average processing unit 82 and the values of P (1), P (2), and P (3) in the memory 81 are updated. Is called. Therefore, when the average value of the detected pressure is newly calculated in the average processing unit 82, the values of P (1), P (2), and P (3) stored in the memory 81 are excluding the beginning of pressure detection. P (1) = Ph calculated previously, P (2) = Ph calculated this time, P (3) = A newly calculated average value, and based on these values, the average airway pressure calculating unit 86 A new average airway pressure Ph will be calculated.
[0097]
On the other hand, the internal pressure control unit 84 determines whether the average airway pressure Ph calculated by the average airway internal pressure calculation unit 86 is higher than a preset target value, and the determination result of the determination unit 88 is high. A drive command output unit 89 that outputs an average airway pressure reduction command to the flow control valve 607 and outputs an average airway pressure increase command to the internal pressure control unit when the determination result is low. .
[0098]
The determination unit 88 is a comparison circuit that compares the average airway pressure Ph calculated by the average airway pressure calculation unit 86 with the target average airway pressure Pg desired by the doctor input to the reception unit 42, and compares the result. Output to the drive command output unit 89. If the comparison result in the determination unit 88 is Pg> Ph, the drive command output unit 89 outputs an operation command for increasing the in-pipe pressure by reducing the opening degree to the flow rate adjustment valve 607, and Pg <Ph. If there is, an operation command for increasing the opening degree of the flow control valve 607 and lowering the pressure in the pipe is output.
[0099]
(Operation of this embodiment)
Hereinafter, the operation of the high-frequency ventilator 12 configured as described above will be described with reference to FIGS. 6 and 7 are flowcharts showing the operation of the high-frequency ventilator 12.
[0100]
In this description of the operation, the tidal volume from the operation panel 43 to the lungs of the patient X, the vibration frequency of the oscillating air pressure, the amount of inspiration, the average airway pressure in the patient side path, the diameter of the selected endotracheal tube 81 The description is started from the state where the oxygen concentration of the inspiration is input and the high-frequency ventilator starts driving.
[0101]
First, the output of the patient side pressure sensor 93 is sampled at 1 [msec] intervals by the sampling unit 80, and sequentially stored in the memory 81 (step S1). When the sampled detected pressure is accumulated for 10 [msec], the average value is calculated by the average processing unit 82 (step S2).
[0102]
When 30 [msec] has elapsed from the start of sampling and the above average value is obtained as detected pressures P (1), P (2) and P (3) in the memory 81 (step S3), the comparison unit At 85, P (1) and P (2), and P (2) and P (3) are compared in size (step S4).
[0103]
Depending on the comparison result, the average airway pressure calculating unit 86 selects the above-described equations (4) to (11) according to the comparison result to calculate the average airway pressure Ph, or the detected pressure P (3). The average airway pressure Ph is output (step S5).
[0104]
The determined average airway pressure Ph is compared with the target value input from the operation panel 43 and stored in the receiving unit by the determining unit 88 (step S6). When the calculated average airway pressure Ph is higher, an operation command to increase the opening degree is output to the flow rate adjustment valve 607, and when the average airway pressure Ph is lower, the flow rate adjustment is performed. An operation command for reducing the opening degree is output to the valve 607 (steps S7 and S8).
[0105]
Further, the detected pressure P (3) stored in the memory is updated by the updating unit 87 to the calculated value of the average airway pressure Ph (step S9).
[0106]
Thereafter, when the detected pressure newly averaged is calculated by the averaging processing unit 82 (step S10), the new detected pressure is changed to P (3) and the original P (3) ( In step S9, the average airway pressure Ph) updated to P (3) is updated to P (2), and the original P (2) is updated to P (1) (step S11).
[0107]
After the update, the same operation is repeated from step S4 described above.
[0108]
(Effect of this embodiment)
Comparison test data between the high-frequency ventilator 12 having the above-described configuration and the conventional high-frequency ventilator 200 are shown in FIGS. 9 shows an enlarged view of a portion A in FIG. 8, and FIG. 10 shows an enlarged view of a portion B in FIG. 9 and 10, the curve L1 in which the gradient changes drastically indicates the pressure detected by the patient-side pressure sensor 93 every 10 [msec] by the conventional high-frequency respirator 200, and the curve L2 indicates the high-frequency respiration. The average airway pressure Ph calculated based on the pressure detected by the patient-side pressure sensor 93 every 10 [msec] by the vessel 12 is shown. Note that the curve L2 is shown slightly shifted downward so as not to overlap the curve L1.
[0109]
As can be seen from the curve L2, according to the present embodiment, the sudden change in the detected pressure is alleviated, and when the flow rate control valve 607 is controlled based on this, control of the high-frequency ventilator that is stable from low frequency can be performed. It becomes possible.
[0110]
Furthermore, FIG. 11 shows the detected pressure (curve L3) of the patient-side pressure sensor 93 in the conventional high-frequency ventilator 200 and the average airway pressure (curve L4) calculated by the conventional controller 201 based on the detected pressure. At the same time, the detected pressure (curve L5) of the patient-side pressure sensor 93 in the high-frequency ventilator 12 and the average airway pressure (curve L6) calculated by the controller 40 based on the detected pressure are shown in FIG. In either case, as the graph proceeds from the left to the right of the graph, operation control is performed so as to approach the target set value according to the calculated average airway pressure.
[0111]
Referring to FIG. 11 of the conventional control, the pressure change due to the operation result of the flow rate adjusting valve 607 and the movement of the flow rate adjusting valve 607 do not coincide with each other due to the influence of air inertia and the like, and therefore the target pressure value increases. The pressure average value of the air vibration cannot be kept constant because it is too low or too low.
[0112]
On the other hand, in the high-frequency ventilator 12 according to this embodiment, the air vibration can be pressure-controlled toward the target value as shown in FIG. 12, and after reaching the target value, a stable average airway pressure can be maintained. it can.
[0113]
In FIG. 12, the pressure is an average value for 10 points of sampling every 1 msec. This controls the flow rate adjustment valve 607 based on the average airway pressure Ph calculated according to the average airway pressure calculator 86 while monitoring new data every 10 msec.
[0114]
As described above, in the high-frequency ventilator 12, the controller 40 averages the pressure detected at a preset sampling interval over a certain period, and when three such average values are obtained, the gradients thereof are obtained. The average airway pressure is calculated from the change. Therefore, the time required for calculating the average airway pressure is not determined by the period of the ventilation frequency as in the past, and even when the ventilation frequency is long (low frequency), it is stable at a finer time interval. High frequency ventilator can be controlled.
[0115]
In the high-frequency ventilator 12 described above, the controller 40 includes the average processing unit 82, but a configuration in which this is omitted is also conceivable. In that case, the detected pressure extracted by the sampling unit 80 is directly processed by the calculation unit 83 via the memory 81.
[0116]
Further, the controller 40 of the high-frequency ventilator 12 may be realized by the configuration shown in FIG. In such a configuration, a disk drive 91 that drives a storage medium D such as a CD-ROM in which a program including instructions for performing operations corresponding to the respective units included in the controller 40 is recorded, and the disk drive 91 is read out. An auxiliary storage device 92 such as a hard disk for storing the program, a central processing unit 93 such as a CPU for performing arithmetic processing according to the program stored in the auxiliary storage device 92, a RAM serving as a main storage of the central processing unit 93, etc. And a main storage unit 94. Here, when “commands that can be operated” are referred to, a predetermined process is realized depending on a case where a predetermined command is realized only by this CPU and a service by an operation system or a program stored in the auxiliary storage device. Including both cases.
[0117]
[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. Of the components shown in the present embodiment, the same components as those shown in the high-frequency ventilator 12 described above will be given the same reference numerals and redundant description will be omitted.
[0118]
In the above-described high-frequency ventilator 12, when the average airway pressure calculation unit 86 has the change pattern of the detected pressures P (1), P (2), P (3) as [A], that is, P (1) ≦ When P (2) <P (3) and P (1) −P (2) + a ≧ P (3) −P (2), the pattern Ps = P (2) + K · β = P (2 ) + K · (P (3) −P (2)) to obtain the corrected pressure Ps, and further to obtain the average airway pressure Ph from Ph = (P (2) + Ps) / 2.
[0119]
However, in this case, since the coefficient K is a fixed value, the accuracy of the calculated value of the average airway pressure Ph is improved when the magnitude of the amplitude of the high frequency oscillating air pressure (tidal volume) is changed according to the patient. As a result, the stability of the control of the flow rate control valve 607 may be slightly reduced.
[0120]
Therefore, in the high frequency ventilator 12A according to the second embodiment, the change pattern of the detected pressures P (1), P (2), P (3) is [A]: P (1) ≦ P (2) <P (3) and P (1) −P (2) + a ≧ P (3) −P (2), the corrected pressure Ps is calculated using the following equation (12), and the following equation (14 ) Is used to calculate an average airway pressure Ph that calculates the average airway pressure Ph.
[0121]
Ps = P (2) + Q · H · (P (3) -P (2)) (12)
[0122]
Ph = (P (2) + Ps) / 2 (13)
[0123]
In the above equation (12), the symbol Q is a coefficient (Q> 0) obtained by simulation or test, and the symbol H is a linear function of the tidal volume of the oscillating air pressure urging unit 50. Use drive output. The drive output H changes in proportion to the tidal volume. The drive output H is calculated by the average airway pressure calculating unit 86 referring to a numerical value set and inputted in advance from the operation panel 43 to the receiving unit 41.
[0124]
FIG. 15 shows the detected pressure (curve L7) of the patient-side pressure sensor 93 in the high-frequency ventilator 12A having the above configuration and the average airway pressure (curve L8) calculated by the controller 40A based on the detected pressure.
[0125]
Compared to the high frequency ventilator 12 described above, it can be seen that the amplitude of the calculated mean airway pressure is narrower in the high frequency ventilator 12A. Thus, in the high-frequency ventilator 12A, since the tidal volume is taken as a parameter in the calculation formula for calculating the average airway pressure Ph, it is possible to effectively cope with such a change in the tidal volume setting. Furthermore, it is possible to control the air vibration more effectively toward the target value, and after reaching the target value, it is possible to maintain a more stable average airway pressure.
[0126]
In the high-frequency ventilator 12A, the drive output of the blower 52 is used as the symbol H, but the numerical value of the tidal volume input from the operation panel may be used. In this case, it is necessary to change the coefficient Q to a numerical value corresponding to it.
[0127]
Further, as shown in FIG. 16, the configuration of the controller 40A described above includes the tidal volume, the vibration frequency of the oscillating air pressure, the supply amount of the inspiratory air, the average airway pressure, and the diameter of the selected endotracheal tube. And the output of the blower 52 from the map memory 95 storing the five-dimensional map with the parameter specifying the output of the oscillating air pressure urging unit, and the input values received by the five-dimensional map and the receiving unit 41, Based on this, a specific unit 96 that performs operation control of the oscillating air pressure urging unit may be newly added, and the average airway pressure Ph may be calculated by referring to the output of the blower 52 specified by the specific unit 96. .
[0128]
The details of the five-dimensional map are described in the specification and drawings attached to the application of Japanese Patent Application No. 11-362346.
[0129]
In such a configuration, since the average airway pressure Ph is calculated based on the function of the tidal volume based on the output of the blower 52 that is actually driven, the setting of the tidal volume can be changed more effectively. Thus, it is possible to control the pressure of the air vibration more effectively toward the target value, and after reaching the target value, it is possible to maintain a more stable average airway pressure.
[0130]
Note that each of the configurations of the controller 40A described above also drives the storage medium D such as a CD-ROM in which the configuration shown in FIG. 13, that is, a program including instructions for performing operations corresponding to the units included in the controller 40A is recorded. The disk drive 91, the auxiliary storage device 92, the central processing unit 93, the main storage unit 94, and the like may be realized.
[0131]
【The invention's effect】
As described above, in the present invention, when three pressures detected at a preset sampling interval are obtained, the average airway pressure is calculated from the gradient changes. Therefore, the time required for calculating the average airway pressure is not determined by the period of the ventilation frequency as in the past, and even when the ventilation frequency is long (low frequency), it is stable at a finer time interval. High frequency ventilator can be controlled.
[0132]
For this reason, it is possible to set the ventilation frequency of the high frequency ventilator from the low frequency range to the high frequency range while stabilizing the control of the average airway pressure, and stable high frequency for a wide range of patients from newborns to adults. Can perform artificial respiration (HFO ventilation).
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a high-frequency ventilator according to a first embodiment.
FIG. 2 is a cross-sectional view showing details of the flow control valve disclosed in FIG. 1;
FIG. 3 is a block diagram showing a control system of the high-frequency ventilator disclosed in FIG. 1;
FIGS. 4A and 4B are diagrams showing a pressure change of an average value of detected pressures sequentially calculated, in which FIG. 4A shows a pattern of [A] and FIG. 4B shows a pattern of [B]. .
FIG. 5 is a diagram showing a pressure change of an average value of detected pressures sequentially calculated, FIG. 5 (C) shows a pattern [C], and FIG. 5 (D) shows a pattern [D]. .
FIG. 6 is a flowchart showing the operation of the high-frequency ventilator disclosed in FIG. 1;
7 is a continuation flowchart of FIG. 6 illustrating the operation of the high frequency ventilator disclosed in FIG. 1;
FIG. 8 is a diagram showing comparison test data between the first embodiment and a conventional example.
9 is an enlarged view of a portion A in FIG.
10 is an enlarged view of a portion B in FIG.
FIG. 11 is a diagram showing a detected pressure of a patient-side pressure sensor and an average airway pressure calculated based on the detected pressure in a conventional high-frequency ventilator.
FIG. 12 is a diagram showing a detected pressure of a patient side pressure sensor in the first embodiment and an average airway pressure calculated based on the detected pressure.
13 is a block diagram illustrating an example of a configuration including a storage medium in which a program for realizing the controller illustrated in FIG. 3 is recorded.
FIG. 14 is a block diagram showing a configuration of a second embodiment.
FIG. 15 is a diagram showing a detected pressure of a patient side pressure sensor and an average airway pressure calculated based on the detected pressure in the second embodiment.
FIG. 16 is a block diagram showing another example of the controller of the second embodiment.
FIG. 17 is a block diagram showing a configuration of a conventional high-frequency ventilator.
FIG. 18 is a conceptual diagram for obtaining an average airway pressure of intake air at a ventilation frequency of 15 [Hz].
[Explanation of symbols]
12,12A high frequency ventilator
40, 40A controller
50 Vibrating air pressure biasing part
60 Patient route
62 Intake air inlet
80 Sampling unit
81 memory
82 Average processing section
83 Calculation unit
84 Internal pressure controller
85 comparison part
86,86A Average airway pressure calculator
87 Update Department
88 judgment part
89 Drive command output section
93 Pressure sensor on patient side
604 discharge pipe (discharge route)
607 Flow rate adjustment valve (internal pressure adjustment part)
D Recording medium

Claims (8)

An inhalation introduction part for supplying inhalation containing oxygen, a patient side path for guiding the inhalation to the patient, a vibration air pressure biasing part for biasing a high frequency vibration air pressure to the patient inhalation, and the patient A discharge path for discharging the exhaled air from the atmosphere, an internal pressure adjusting unit for adjusting an average airway internal pressure of the intake air supplied to the patient, a pressure sensor for detecting the pressure of the inhalation near the patient, and the pressure sensor A high frequency ventilator comprising a controller for controlling the operation of the internal pressure adjusting unit based on the output of
The controller includes a sampling unit that sequentially extracts a detected pressure at a predetermined sampling interval from the output of the pressure sensor;
Three detected pressures P (1), P (2), P (3) are stored in the order of extraction, and each time a new detected pressure is extracted, the detected pressures P (1), P (2), Memory to update P (3);
According to the pressure change pattern of the three detected pressures P (1), P (2), P (3),
a is a predetermined pressure difference, K, L, M, N, O are predetermined coefficients ,
Pattern of the pressure change, P (1) ≦ P ( 2) <P (3) and P (1) - P (2 ) + a ≧ P (3) - in the case of P (2), the corrected pressure Ps calculated from - (P (2) P ( 3)), wherein Ps = P (2) + K ·
The pattern of pressure changes, in the case of P (1)> P (2 )> P (3), the corrected pressure Ps formula Ps = P (2) - { P (1) - P (2) + L · ( P (2) - is calculated from P (3))},
When the pressure change pattern is P (1) < P (2) and P (2) > P (3) , the corrected pressure Ps is expressed by the formula Ps = P (2) −M · ( P (2) − P (1)) -N · ( P (2) - is calculated from P (3)),
The pattern of pressure changes, P (1)> P ( 2) and P (2) <P (3 ) in the case of the formula Ps = O · corrective pressure Ps (P (1) - P (2)) Calculated from + P (2)
While calculating the expression Ph = (P (2) + Ps) / 2 wherein the mean airway pressure Ph on the basis of containing any modifications pressure Ps of the calculated,
When the pressure change pattern does not correspond to any of the cases, the calculation unit that directly uses the detected pressure P (3) as the average airway pressure Ph, and when the average airway pressure Ph is calculated, the calculated Ph is used as the detected pressure P. (3) A high-frequency ventilator comprising an update unit for writing into the memory. An inhalation introduction part for supplying inhalation containing oxygen, a patient side path for guiding the inhalation to the patient, a vibration air pressure biasing part for biasing a high frequency vibration air pressure to the patient inhalation, and the patient A discharge path for discharging the exhaled air from the atmosphere, an internal pressure adjusting unit for adjusting an average airway internal pressure of the intake air supplied to the patient, a pressure sensor for detecting the pressure of the inhalation near the patient, and the pressure sensor A high frequency ventilator comprising a controller for controlling the operation of the internal pressure adjusting unit based on the output of
The controller includes a sampling unit that sequentially extracts a detected pressure at a predetermined sampling interval from the output of the pressure sensor ;
Three detected pressures P (1), P (2), P (3) are stored in the order of extraction, and each time a new detected pressure is extracted, the detected pressures P (1), P (2), Memory to update P (3) ;
According to the pressure change pattern of the three detected pressures P (1), P (2), P (3) ,
a is a predetermined pressure difference, L, M, N, O, and Q are predetermined coefficients, and a function of the ventilation amount of one cycle of the oscillating air pressure biasing unit is H ,
Pattern of the pressure change, P (1) ≦ P ( 2) <P (3) and P (1) - P (2 ) + a ≧ P (3) - in the case of P (2), the corrected pressure Ps Calculated from the formula Ps = P (2) + Q · H · ( P (3) – P (2) )
The pattern of pressure changes, in the case of P (1)> P (2 )> P (3), the corrected pressure Ps formula Ps = P (2) - { P (1) - P (2) + L · ( P (2) - is calculated from P (3))},
When the pressure change pattern is P (1) < P (2) and P (2) > P (3) , the corrected pressure Ps is expressed by the formula Ps = P (2) −M · ( P (2) − P (1)) -N · ( P (2) - is calculated from P (3)),
The pattern of pressure changes, P (1)> P ( 2) and P (2) <P (3 ) in the case of the formula Ps = O · corrective pressure Ps (P (1) - P (2)) Calculated from + P (2)
While calculating the expression Ph = (P (2) + Ps) / 2 wherein the mean airway pressure Ph on the basis of containing any modifications pressure Ps of the calculated,
The detected pressure P (3) and a computing unit to mean airway pressure Ph as, the mean airway pressure Ph when is calculated the Ph of the sensed pressure P when the pattern of the pressure change does not correspond to any case (3) A high-frequency ventilator comprising an update unit for writing into the memory . The high-frequency ventilator according to claim 1 or 2 , wherein the controller includes an internal pressure control unit that performs operation control of the internal pressure adjustment unit so that the average airway pressure Ph becomes a target value. The controller has an averaging processing unit that averages each time a predetermined number of detected pressures are extracted from the sampling unit and outputs the value to the memory as the detected pressure,
The arithmetic unit, the high frequency ventilator as claimed in claim 1, 2 or 3, wherein the calculating the mean airway pressure on the basis of the averaged sensed pressure. An inhalation introduction part for supplying inhalation containing oxygen, a patient side path for guiding the inhalation to the patient, a vibration air pressure biasing part for biasing a high frequency vibration air pressure to the patient inhalation, and the patient A high frequency provided with an exhaust path for discharging exhaled air from the atmosphere, an internal pressure adjustment unit for adjusting an average airway internal pressure of inspiration supplied to the patient, and a pressure sensor for detecting the pressure of inhalation near the patient A ventilator operation control program comprising:
A sampling unit that sequentially extracts the detected pressure at predetermined sampling intervals from the output of the pressure sensor that is continuously input;
Three detected pressures P (1), P (2), P (3) are stored in the order of extraction, and each time a new detected pressure is extracted, the detected pressures P (1), P (2), Memory to update P (3),
According to the pressure change pattern of the three detected pressures P (1), P (2), P (3) extracted in order,
a is a predetermined pressure difference, K, L, M, N, O are predetermined coefficients ,
Pattern of the pressure change, P (1) ≦ P ( 2) <P (3) and P (1) - P (2 ) + a ≧ P (3) - in the case of P (2), the corrected pressure Ps calculated from - (P (2) P ( 3)), wherein Ps = P (2) + K ·
The pattern of pressure changes, in the case of P (1)> P (2 )> P (3), the corrected pressure Ps formula Ps = P (2) - { P (1) - P (2) + L · ( P (2) - is calculated from P (3))},
When the pressure change pattern is P (1) < P (2) and P (2) > P (3) , the corrected pressure Ps is expressed by the formula Ps = P (2) −M · ( P (2) − P (1)) -N · ( P (2) - is calculated from P (3)),
The pattern of pressure changes, P (1)> P ( 2) and P (2) <P (3 ) in the case of the formula Ps = O · corrective pressure Ps (P (1) - P (2)) Calculated from + P (2)
While calculating the expression Ph = (P (2) + Ps) / 2 wherein the mean airway pressure Ph on the basis of containing any modifications pressure Ps of the calculated,
Calculator directly with the mean airway pressure Ph of the detected pressure P (3) when the pattern of the pressure change does not correspond to any case,
And, when this average airway pressure Ph is calculated, the operation control program of the high-frequency ventilator provided with a command to make the computer function as an update unit that writes the Ph to the memory as the detected pressure P (3) was recorded. Computer-readable recording medium. An inhalation introduction part for supplying inhalation containing oxygen, a patient side path for guiding the inhalation to the patient, a vibration air pressure biasing part for biasing a high frequency vibration air pressure to the patient inhalation, and the patient A high frequency provided with an exhaust path for discharging exhaled air from the atmosphere, an internal pressure adjustment unit for adjusting an average airway internal pressure of inspiration supplied to the patient, and a pressure sensor for detecting the pressure of inhalation near the patient A ventilator operation control program comprising :
A sampling unit that sequentially extracts the detected pressure at predetermined sampling intervals from the output of the pressure sensor that is continuously input ;
Three detected pressures P (1), P (2), P (3) are stored in the order of extraction, and each time a new detected pressure is extracted, the detected pressures P (1), P (2), Memory to update P (3) ,
According to the pressure change pattern of the three detected pressures P (1), P (2), P (3) extracted in order ,
a is a predetermined pressure difference, L, M, N, O, and Q are predetermined coefficients, and a function of the ventilation amount of one cycle of the oscillating air pressure biasing unit is H ,
Pattern of the pressure change, P (1) ≦ P ( 2) <P (3) and P (1) - P (2 ) + a ≧ P (3) - in the case of P (2), the corrected pressure Ps Calculated from the formula Ps = P (2) + Q · H · ( P (3) – P (2) )
The pattern of pressure changes, in the case of P (1)> P (2 )> P (3), the corrected pressure Ps formula Ps = P (2) - { P (1) - P (2) + L · ( P (2) - is calculated from P (3))},
When the pressure change pattern is P (1) < P (2) and P (2) > P (3) , the corrected pressure Ps is expressed by the formula Ps = P (2) −M · ( P (2) − P (1)) -N · ( P (2) - is calculated from P (3)),
The pattern of pressure changes, P (1)> P ( 2) and P (2) <P (3 ) in the case of the formula Ps = O · corrective pressure Ps (P (1) - P (2)) Calculated from + P (2)
While calculating the expression Ph = (P (2) + Ps) / 2 wherein the mean airway pressure Ph on the basis of containing any modifications pressure Ps of the calculated,
When the pressure change pattern does not correspond to any case, the calculation unit that directly sets the detected pressure P (3) as the average airway pressure Ph ,
And, when this average airway pressure Ph is calculated , the operation control program of the high-frequency ventilator provided with a command to make the computer function as an update unit that writes the Ph to the memory as the detected pressure P (3) was recorded. Computer-readable recording medium . The determination unit that compares and determines the calculated average airway pressure Ph and a preset target value, and the average airway to the internal pressure adjustment unit when the average airway pressure is high as a result of determination by the determination unit outputs pressure reduction command, the average claim wherein the internal pressure control unit mean airway pressure increase command drive command output unit for outputting to, with a command to newly function computer when airway pressure is lower 5 Or the computer-readable recording medium which recorded the operation control program of the high frequency ventilator of 6. Each time a predetermined number of detected pressures are extracted from the sampling unit, the average processing unit that averages them and outputs the value as the detected pressure sequentially to the calculation unit, and a new computer function,
The operation control of the high-frequency ventilator according to claim 5, 6 or 7 , wherein the calculation unit includes a command for causing a computer to function so as to calculate the average airway pressure based on the averaged detected pressure. A computer-readable recording medium on which a program is recorded.

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