JP2011045592A - Monitor system and control method for monitor system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a monitor system capable of monitoring the intake and ejection of general respiratory gas. <P>SOLUTION: The monitor system includes a flow sensor provided in a respiratory circuit to continuously detect a patient's respiratory volume; a respiratory gas sensor provided in the respiratory circuit to continuously detect the concentration of respiratory gas containing anesthetic gas; and a display control part for depicting almost in real time a volume change on the time axis of the patient's respiration measured by the flow sensor, tidal volume obtained from the volume change, a concentration change of respiratory gas containing anesthetic gas on the time axis of the patient's respiration measured by the respiratory gas sensor, and intake concentration and exhalation final concentration obtained from the concentration change. The display control part continuously displays points (C, V) of the same point of time on X-Y coordinates from a change V of tidal volume by the flow sensor on the time axis and a concentration change C of each respiratory gas by the respiratory gas sensor, and depicts loops for every respiration. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a monitor system and a monitor system control method.

  Inhalation general anesthesia has a history of more than 160 years since its clinical application in 1846. Various studies have been conducted on the intake of anesthesia gas and respiratory gas during general anesthesia, but clinical monitoring of the intake and excretion of oxygen and carbon dioxide has been realized in a small part.

An SBCO ₂ (Single Breath CO ₂ ) monitor has been proposed for monitoring carbon dioxide (see Patent Document 1). This SBCO ₂ is drawn as a waveform for carbon dioxide only for one exhalation with the exhalation volume on the X axis and the carbon dioxide concentration on the Y axis. FIG. 1 is a diagram showing a display example of a conventional SBCO ₂ monitor. From this waveform, values of end-tidal carbon dioxide concentration ETCO ₂ , tidal volume VE, dead space volume VD, and alveolar ventilation VA are obtained, and carbon dioxide excretion volume VCO ₂ is calculated from the area under the waveform line. be able to.
Japanese Patent Laid-Open No. 9-24099

However, normally, carbon dioxide is hardly included in inspiration, so the SBCO ₂ monitor is only for expiratory flow. Other respiratory gases, oxygen, nitrous oxide, volatile anesthetic gases, etc. are also included in the inspiration, so intake / excretion cannot be monitored with an analysis of only exhalation like the SBCO ₂ monitor. It was.

  Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide a monitor system capable of monitoring intake and excretion of general respiratory gas and a control method of the monitor system.

  In order to solve the above-mentioned problems, a monitor system of the present invention detects a change in the concentration of respiratory gas including an anesthetic gas provided in the breathing circuit and a flow sensor provided in the breathing circuit for detecting volume change of patient breathing. Respiratory gas sensor, volume change on the time axis measured by the flow sensor, and tidal volume obtained therefrom, gas concentration change on the time axis measured by the respiratory gas sensor, and from there A display control unit that draws the obtained inspiratory concentration and end-expiratory concentration almost as real time, and the display control unit includes a change V of the tidal volume by the flow sensor on the time axis and the respiratory gas sensor. From the concentration change C of each respiratory gas, the point (C, V) at the same time point is continuously displayed on the XY coordinates, and a loop is drawn for each breath.

  According to the present invention, by plotting the ventilation volume V and the respiratory gas concentration C, which are the two major elements of inhalation anesthesia, on the XY coordinates, each value and the relationship between the values can be intuitively recognized. In addition to carbon dioxide, it is possible to monitor the intake and excretion of breathing gas in general. Furthermore, alveolar ventilation can be monitored in addition to tidal volume, inspiratory concentration, and end-tidal concentration. In addition, since it is possible to graphically represent the intake and excretion of respiratory gases and their changes in each phase of introduction to maintenance to awakening, which is a series of inhalation-type general anesthesia, it can be used as a normal integrity monitor for inhalation anesthesia from a large field of view. Can also be expected.

  In the above invention, the display control unit calculates, for a plurality of gases that can be detected by the respiratory gas sensor, the concentration C of the respiratory gas at a certain point in time and the tidal volume V by the flow sensor at the same point in time as 0 -The loop is drawn for each breath by controlling to display continuously as points (C, V) on the coordinate plane composed of the X axis of 100% and the Y axis of tidal volume .

  In the above invention, the display control unit calculates the area of a closed rectangular part of a VC (Volume-Concentration Loop) loop of each respiratory gas, and the calculated area of the rectangular part is calculated as the intake amount of the respiratory gas. Alternatively, it is calculated as an excretion amount and displayed in a predetermined display area.

  In addition, the control method of the monitor system of the present invention includes a volume change on a time axis of patient respiration detected by a flow sensor, a tidal volume obtained therefrom, and a time axis of patient respiration detected by a respiratory gas sensor. This is a display control method for a monitor system that draws the change in concentration of respiratory gas including anesthetic gas and the inhalation concentration and end-expiratory concentration obtained from the changes almost in real time. From the change in tidal volume V and the change in concentration C of each respiratory gas by the respiratory gas sensor, the point (C, V) at the same time point is continuously displayed on the XY coordinates, and a loop is made for each breath. Including the step of rendering.

  In the above invention, for a plurality of gases that can be detected by the breathing gas sensor, the concentration C of the breathing gas at a certain point in time and the tidal volume V by the flow sensor at the same point in time are set to 0-100% of the X axis. Then, the loop is drawn for each breath by controlling to display continuously as points (C, V) on the coordinate plane constituted by the Y axis of the tidal volume.

  In the above invention, the area of the closed rectangular part of the VC loop of each respiratory gas is calculated, and the calculated area of the rectangular part is calculated as the amount of intake or excretion of the respiratory gas to obtain a predetermined display area. The method further includes displaying.

  Here, respiratory gases such as oxygen and anesthetic gas that enter the lungs from the airways move from the alveoli to the blood of the capillaries. This movement is called intake. On the other hand, carbon dioxide generated in the tissue dissolves in venous blood, returns to the heart, passes through the pulmonary artery, and moves to the alveoli in the form of capillaries of the alveoli, replacing oxygen. This movement is called excretion. Excretion and ingestion may be considered to be the same phenomenon in terms of gas exchange between the alveoli and their capillaries only in different directions. In other words, excretion is a negative intake.

  ADVANTAGE OF THE INVENTION According to this invention, the monitoring system which can monitor the intake and excretion of the breathing gas generally, and the control method of a monitor system can be provided.

It is a diagram illustrating a display example of a conventional SBCO ₂ monitor. It is a figure for demonstrating the anesthesia system which concerns on embodiment of this invention. It is a figure which shows the connection relation of the display control apparatus of a flow sensor and a respiratory gas sensor. It is a figure for demonstrating the intake and excretion amount by a VC loop. It is an example of a display of the V-C loop of each gas at the time of anesthesia maintenance state. It is an example of a display of the ingestion monitor in the representative process of inhalation type general anesthesia. It is a figure which shows the example of a display of a display apparatus. It is a figure for demonstrating the artificial respiration system which concerns on other embodiment of this invention.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the accompanying drawings.

  FIG. 2 is a diagram for explaining an anesthesia system according to an embodiment of the present invention. As shown in FIG. 2, the anesthesia system 100 includes an anesthetic gas supply device 1, a breathing circuit 2, a display control device (display control unit) 3, and a display device 4.

The breathing circuit 2 includes an inhalation valve 21, a connector 22 connected to a patient, a flow sensor 23, a breathing gas sensor 24, an exhalation valve 25, a CO ₂ absorbent canister 26, and a ventilator 27. The inhalation valve 21 operates so as to allow the flow of gas (inspiration) from the breathing circuit 2 to the patient but restrict the reverse flow.

A flow sensor 23 and a respiratory gas sensor 24 are installed in the connector 22 in series in any order. The flow sensor 23 detects a volume change on the time axis of respiration, and further measures a tidal volume therefrom. The respiratory gas sensor 24 is constituted by, for example, a multi-gas sensor module, detects a change in concentration of respiratory gas including anesthetic gas on the time axis, and further measures an inspiratory concentration and an end expiratory concentration therefrom. Here, the flow sensor 23 and the respiratory gas sensor 24 measure the respiratory gas mixed with carbon dioxide (CO ₂ ), volatile anesthetic gas (AA), oxygen (0 ₂ ), and nitrous oxide (N ₂ O). be able to. The ventilator 27 is used to promote, assist or force patient inspiration and expiration.

  The connection relationship between the flow sensor 23 and the respiratory gas sensor 24 with the display control device 3 is shown in FIG. Signals detected in each of the flow sensor 23 and the respiratory gas sensor 24 by the passing respiratory gas are supplied to the display control device 3.

The gas analysis method is preferably a mainstream gas analysis method. In the conventional gas analysis method using the mainstream side stream, inspiratory gas / expired gas is continuously sampled around 100 mL / min from the mouth, detected by a remote sensor, concentration change on the time axis, and inspiratory concentration / expired gas The terminal concentration is measured and displayed. For this reason, it was difficult to handle it with the tidal volume data integrally due to mixing during sampling, time difference until measurement, and the like. The mainstream gas sensor module that can continuously monitor the concentration of anesthetic respiratory gases such as CO ₂ / O ₂ / N ₂ O / AA at the patient's mouth in near real time makes it possible to take a tidal volume. And respiratory gas concentration data can now be handled together on the same time axis.

The exhalation valve 25 guides part of the exhalation from the patient to the CO ₂ absorbent canister 26 for reuse, and discards the remaining part as surplus gas. The flow is allowed, but the reverse flow is regulated. Operates to The CO ₂ absorbent canister 26 is for absorbing and removing carbon dioxide from the patient's exhalation and for circulating other anesthetic respiratory gases as part of inspiration.

  The display device 4 is configured by a liquid crystal display, for example. The display control device 3 controls the entire display device 4, a signal indicating a change in volume V on the time axis detected by the flow sensor 23, and a concentration C on the time axis detected by the respiratory gas sensor 24. And at least a function of rendering a signal as a real-time waveform.

  FIG. 4 is a diagram for explaining the intake and excretion by the VC loop, where (a) is a diagram for explaining intake and (b) is a diagram for explaining excretion. As shown in FIG. 4, the display control device 3 displays the change V of the tidal volume by the flow sensor 23 on the time axis and the concentration change C of each respiratory gas by the respiratory gas sensor 24 on the XY coordinates. Points (C, V) at the same time are displayed continuously, and a VC loop is drawn for each breath. The V-C loop is a plot of ventilation volume V and respiratory gas concentration C, which are two major elements of inhalation anesthesia, on XY coordinates. This loop makes it possible to intuitively recognize each measured value and its relationship.

  As shown in FIG. 4, changes in ventilation volume V and concentration C, which are the two major elements of inhalation anesthesia, can be expressed in a fixed form (alphabet small letter d or b). “D-type” shown in FIG. 5A indicates gas intake, and “b-type” shown in FIG. 5B indicates gas excretion. The length of the rod portion of the loop is the dead space amount VD, the height of the closed portion is the alveolar ventilation VA, the area is the intake (or excretion) amount of the gas, “d-type” is the intake, “B-type” can express excretion, respectively.

Further, as shown in FIG. 4A, from the relationship of the area of each region, if the intake amount (uptake volume) of a certain gas ** is Vup **, the intake amount Vup ** = VT × FI ** 1. ― (VD × FI ** 1 + VA × ET **)
= (VT-VD) x FI ** 1-VA x ET **
= VA * (FI ** 1-ET **).
As seen in the waveform of SBCO ₂ shown in FIG. 1, the VC loop in the actual lung is such as the presence of bronchioles that are not ventilated or the presence of insufficient or insufficient alveoli. As a result, the four corners do not necessarily have a square shape, and an accurate alveolar ventilation VA cannot be obtained from only the figure. However, since the intake amount Vupt ** can be obtained from the integration of the VC loop, more appropriate alveolar ventilation can be obtained by VA = Vupt ** / (FI ** 1-ET **) obtained by modifying the above equation. The quantity VA can be determined.
Further, as shown in FIG. 4B, when the excretion amount of a certain gas ** is Vexh **, the excretion amount Vexh ** = VA × (ET ** − FI ** 2). In FIG. 4B, when FI ** 2 = 0, for example, the amount of carbon dioxide excreted is represented.

The intake amount refers to the amount of gas exchange with blood in the alveoli. The exchange amount at the patient's mouth, which is the measurement site of respiratory gas, is the movement amount Vtran **, the lung volume (functional residual capacity FRC + death If the amount of a certain gas ** contained in the cavity volume VD) is Vcont **, the intake amount Vup ** is the amount obtained by subtracting the amount of change in the pulmonary inclusion gas, that is, Vupt ** = Vtran ** − ΔVcont **.
ΔVcont is zero when the patient's circulatory index is stable and respiratory indices such as tidal volume VT, inspiratory concentration FI **, and end-tidal concentration ET ** are stable as in the state of anesthesia maintenance. Therefore, the amount of intake matches the amount of movement.
If an amount of fresh gas having a composition equal to the total Vuptot of all gas intake (Vuptop = FGF) is supplied, only the amount of gas required by the patient is supplied and an anesthesia that does not generate exhausted surplus gas is generated. That is, it becomes a complete closed anesthesia. When a reliable intake monitor is realized, automatic control of fresh gas flow rate and composition is possible due to fully closed anesthesia.

The conventional SBCO ₂ monitor shows changes in exhaled CO ₂ concentration on the Y axis and changes in exhaled gas on the X axis, and monitors dead space and carbon dioxide excretion from the waveform and area. is there. On the other hand, the V-C loop represents the gas concentration as the X-axis, the tidal volume as the Y-axis, and a continuous inspiration / expiration loop. Can be monitored.

Next, an example in which the VC loops for a plurality of gases are displayed simultaneously will be described. FIG. 5 is a display example of each gas loop in the state of anesthesia maintenance (stable). As shown in FIG. 5, the display control device 3 includes a plurality of gases (carbon dioxide (CO ₂ ), volatile anesthetic gas (AA), oxygen (O ₂ ), nitrous oxide (N ₂ O)), the concentration change C of each breathing gas is on the X axis of 0-100%, and the change V of the tidal volume by the flow sensor 23 at the same time is on the Y axis. V-C loop is drawn for each breath by controlling to display continuously as V). In that case, in order to distinguish each loop clearly, a loop is drawn by color-coding for each gas.

  By displaying in this way, as shown in the example of FIG. 5, a plurality of indices relating to “amount” and “concentration”, which are two major elements of inhalation anesthesia, tidal volume VT, alveolar ventilation VA, death The cavity volume VD, the inhalation concentration FI **, the end-expiratory concentration ET **, and the intake (or excretion) V ** of a certain gas ** on one XY coordinate, the height and area of each loop・ Simultaneous and intuitive monitoring is possible depending on the position on the X axis.

Further, the display control device 3 determines each respiratory gas (CO ₂ , AA) based on the change in the tidal volume detected and measured by the flow sensor 23 and the change in the gas concentration detected and measured by the respiratory gas sensor 24. , O ₂ , N ₂ O), draw the VC loop, calculate the area of the closed square part, and calculate the area of the square part VCO ₂ , VAA, VO ₂ , VN ₂ O as the breathing gas Is displayed in a predetermined display area 41 in the display device 4 (see FIG. 7).

  FIG. 6 is a display example of an intake monitor in a representative process of inhalation general anesthesia. The display control device 3 performs color display of each loop for each gas. This will be described below with reference to FIGS.

(1) Oxygenation (denitrification)
In normal inhalation general anesthesia, this denitrification process is used before the anesthetic gas is started. As shown in FIG. 6A, 100% pure oxygen is supplied as a fresh gas with a sufficient flow rate in place of 21% FIO ₂ in the air. Nitrogen N ₂ dissolved in the tissue and blood is discharged from the exhaled air, and oxygen O ₂ is combined with hemoglobin in the blood and sent to the whole body tissue to raise ETO ₂ . Denitrification is complete when ETO ₂ approaches FIO ₂ and stabilizes. The area of the loop in this stable state is the oxygen uptake VO ₂ .

(2) Start of anesthesia (N ₂ O / AA start)
As shown in FIG. 6 (b), for example, when FIO _{2 is set} to 35%, FIN ₂ 0 is set to 60%, and FIAA is set to 5%, ETO ₂ is rapidly excreted from the living body and the respiratory circuit after denitrification (“ b-type ") decreases. N ₂ O and AA are taken into the living body from the breathing circuit (“d-type”), and ETN ₂ 0 and ETAA gradually rise and approach FIN ₂ 0 and FIAA.

(3) Stable anesthesia maintenance state of FI ** / ET ** As shown in FIG. 5, the closed area of each gas loop in this state is the amount of movement between alveoli and blood. It is equal to the intake in the state. Carbon dioxide is “negative intake” or excretion.

(4) Awakening (N ₂ O / AA stop (begin washing))
The supply of nitrous oxide N ₂ O and volatile anesthetic gas AA as fresh gas is stopped, and oxygen 100% is supplied instead. As shown in FIG. 6C, ETN ₂ O and ETAA are washed out of the respiratory circuit by oxygen and rapidly decrease. However, since N ₂ O · AA dissolved in blood and tissues moves from the pulmonary artery to the alveoli, the end-expiratory concentration does not immediately become zero. At this time, especially when the flow rate of fresh gas is smaller than the minute ventilation, re-use of expiration occurs, so that washing of N ₂ O · AA from the living body is delayed, that is, awakening is delayed.

(5) Awakening (N ₂ O / AA stop (washing completed))
ETN ₂ O · ETAA is washed out by the flow rate of fresh oxygen (+ air) above the minute ventilation, and approaches zero. A volatile anesthetic gas with low solubility in blood, such as sevoflurane, has an ET ** approaching zero in a short period of time and a quick arousal.

  In this way, the VC loop has excellent intuitive recognition required for clinical monitors, and can represent each process of inhalation general anesthesia as a representative image, so that educational effects, risk management of general anesthesia, The navigation function can also be expected. Since the intake amount of each breathing gas and the total intake amount as a sum thereof can be grasped, the minimum supply amount of fresh gas required is known. As a result, the amount of anesthetic gas to be wasted can be minimized, and the economic and environmental burden can be minimized.

  FIG. 7 is a diagram illustrating a display example of the display device. The figure (a) has shown the example of a display of the monitor incorporated in the ventilator for anesthesia. Regarding ventilation, the airway pressure waveform P on the time axis is representative, and there are also a flow waveform F and a volume waveform V on the time axis. Furthermore, a combination of these P / F / V may use a PV loop / FV loop that can intuitively grasp the ventilation mechanics of the lung. As for the respiratory gas concentration, a carbon dioxide waveform (capnogram) on the time axis that can intuitively grasp the normality of respiration (ventilation) is representative. As shown in FIG. 4B, the display device 4 continuously includes a change V in tidal volume by the flow sensor 23 and a change C in the concentration of each respiratory gas by the respiratory gas sensor 24 on the XY coordinates. As a typical loop, multiple respiratory gases are depicted. It is also possible to take out a certain gas ** and display the enlarged V-C loop. As a result, detailed analysis and examination of alveolar ventilation VA, dead space VD, intake V ** and the like as shown in FIG. 4 are possible.

  According to this V-C loop display, (1) by plotting the ventilation volume V and the respiratory gas concentration C, which are the two major elements of inhalation anesthesia, on the XY coordinates, the respective values and their relations are plotted. Intuitive recognition. In addition to carbon dioxide, it is possible to monitor the intake and excretion of breathing gas in general. (2) In addition to the traditionally important monitoring items, tidal volume VT, inspiratory concentration FI **, and end-tidal concentration ET **, it is difficult to monitor intraoperatively in spite of its high importance as a respiratory index. It becomes possible to monitor the alveolar ventilation VA. (3) The amount of movement of the respiratory gas can be monitored from the area of the loop region represented by the tidal volume and concentration. In particular, when the tidal volume / concentration is stable, such as during anesthesia maintenance during surgery, this amount of movement corresponds to the amount of intake, that is, the amount of gas exchange between the alveoli and blood.

  In addition, (4) the intake and excretion of a specific gas can be seen at a glance depending on whether the inspiratory concentration FI ** is on the left or right side of the end-expiratory concentration ET **. (5) It is possible to graphically represent intake / excretion of respiratory gas and changes thereof in each phase of introduction to maintenance to awakening, which are a series of flows of inhalation general anesthesia. As a result, a function as a normal integrity monitor for inhalation anesthesia can be expected from a large field of view.

FIG. 8 is a view for explaining an artificial respiration system according to another embodiment of the present invention. As shown in FIG. 8, the artificial respiration system 200 includes a ventilator device 201, a connector 202, a flow sensor 203, a gas sensor 204, a display control device 3, and a display device 4. The ventilator device 201 is used to promote, assist or force patient inspiration and expiration. As shown in FIG. 8, the present invention can be applied not only to the example of the inhalation anesthesia system having the circulatory breathing circuit shown in FIG. 2, but also to a non-surgical artificial ventilation system using the ventilator device 201. .
Furthermore, the monitor composed of the flow sensor 203, the gas sensor 204, the display control device 3, and the display device 4 can be applied to spontaneous breathing by removing the ventilator 201 and the inspiration / expiration circuit from FIG. In other words, even in normal breathing that does not use medical gases such as anesthesia gas or high-concentration oxygen, the drawing of the VC loop as described above, and VT / VA / VD, FI ** / ET for oxygen / carbon dioxide Measurement and display of ** / V ** is possible.

  In addition, each step of the control method of the monitor system of this invention is implement | achieved when the display control apparatus 3 runs a predetermined | prescribed program.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. It can be changed. The monitor system of the present invention can also be applied to an automatic anesthesia system that automatically controls the composition and amount of fresh gas, ventilation conditions of the ventilator, etc. so that the supply gas is equal to the intake gas.

100, 200 Anesthesia system 1 Anesthetic gas supply device 2 Breathing circuit 21 Inhalation valve 22, 202 Connector 23, 203 Flow sensor 24, 204 Breathing gas sensor 25 Exhalation valve 3 Display control device 4 Display device 26 CO ₂ absorbent canister

Claims (6)

A flow sensor provided in a breathing circuit for continuously detecting a patient's breathing volume;
A breathing gas sensor that is provided in the breathing circuit and continuously detects the concentration of the breathing gas including anesthetic gas;
Changes in volume on the time axis of patient respiration measured by the flow sensor, and tidal volume obtained therefrom, and respiratory gas including anesthetic gas on the time axis of patient respiration measured by the respiration gas sensor A display control unit that draws a change in concentration, and an inspiratory concentration and an end-expiratory concentration obtained therefrom in substantially real time,
From the change V of the tidal volume by the flow sensor on the time axis and the concentration change C of each respiratory gas by the respiratory gas sensor on the time axis, the display control unit has a point (C, V ) Is continuously displayed and a loop is drawn for each breath. For the plurality of gases that can be measured by the breathing gas sensor, the display control unit sets a concentration C of the breathing gas at a certain time point and a tidal volume V by the flow sensor at the same point of time to 0 to 100%. It is characterized in that the loop is drawn for each breath by controlling to display continuously as points (C, V) on the coordinate plane composed of the X axis and the Y axis of tidal volume. The monitor system according to claim 1. The display control unit calculates the area of the closed rectangular part of the VC loop of each respiratory gas, calculates the area of the rectangular part as the intake or excretion of the respiratory gas, and calculates a predetermined display area. The monitor system according to claim 1, wherein the monitor system is displayed. Volume change on the time axis of patient respiration measured by a flow sensor that continuously detects respiration volume, and tidal volume obtained therefrom,
Changes in the concentration of respiratory gas, including anesthetic gas, on the time axis of patient breathing measured by a respiratory gas sensor that continuously detects the concentration of respiratory gas, including anesthetic gas, and inspiratory and end-tidal concentrations obtained therefrom A control method for a monitor system that renders in almost real time,
The point (C, V) at the same time point is continuously displayed on the XY coordinates from the change V of the tidal volume by the flow sensor on the time axis and the concentration change C of each respiratory gas by the respiratory gas sensor. And a step of drawing a loop for each breath. For a plurality of gases that can be detected by the breathing gas sensor, the concentration C of a certain breathing gas at a certain point in time and the tidal volume V by the flow sensor at the same point in time are set to 0-100% X-axis and once 5. The loop is drawn for each breath by controlling to display continuously as points (C, V) on a coordinate plane constituted by the Y-axis of the ventilation volume. Monitoring system control method. The step of calculating the area of the closed rectangular part of the VC loop of each breathing gas, calculating the area of the square part as the amount of intake or excretion of the breathing gas, and displaying it on a predetermined display area is further included. 6. The method of controlling a monitor system according to claim 4 or claim 5, further comprising:

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