WO2014171547A1 - Walking test device - Google Patents

Abstract

The present invention measures breathing frequency, respiratory minute volume equivalent and tidal volume equivalent and graphically indicates the same on a common time axis to enable comparison. With the lapse of time from the start of measurements, first the rise in the breathing frequency, respiratory minute volume equivalent and tidal volume equivalent is moderated (after three minutes), after which the rise in pulse rate is moderated (after four minutes). Since the items in the respiratory system have reached their peak quicker than the item in the circulatory system, it can be presumed that the functions of the respiratory system were not able to keep up with the increase in the amount of exercise and, as a result, the walking distance was limited.

Description

Walking test device

The present invention relates to a walking test apparatus for measuring arterial blood oxygen saturation (hereinafter referred to as “SpO ₂ ”) or the like when a measurement subject is walking.

For example, a 6-minute walking test (hereinafter sometimes referred to as 6MWT) as shown in Non-Patent Document 1 is known. The 6-minute walking test is a test for measuring the maximum distance that can be walked at a self-paced pace for 6 minutes, and is a test for evaluating exercise ability based on the distance. Standardized as an exercise endurance test by the American Thoracic Society (ATS) in 2002. In the 6-minute walking test, the strength of shortness of breath and the feeling of fatigue are evaluated using a modified Borg scale before and after walking and during walking. The modified Borg scale is a scale for evaluating the degree of dyspnea as shown in FIG. 1, and confirming with the measured person which scale of dyspnea is met during walking (direct evaluation). Thus, the state of the person being measured while walking is evaluated.

Japanese Patent No. 4008953

The evaluation based on the modified Borg scale described above is suitable for measuring the relative time course of dyspnea in the same subject. On the other hand, since the measured value is influenced by the subjectivity of the subject, there is a problem that the state of the subject cannot be quantitatively evaluated, and there is a limit to the comparison between different groups. In recent years, the oxygen saturation (SpO ₂ ) can be measured by a 6-minute walking test apparatus worn by the person to be measured, which makes it possible to grasp the state of the person being measured during the walking test. However, there is a problem that it is difficult to estimate an exercise limiting factor (a factor that suppresses the walking distance for 6 minutes) in the 6-minute walking test.

The present invention has been made based on such a background, and the purpose of the present invention is to quantitatively evaluate the state of a person to be measured in a walking test such as a 6-minute walking test and to estimate an exercise limiting factor. An object of the present invention is to provide a walking test apparatus that enables this.

The following measures were taken to solve the above problems. The reference numerals used in the description of the best mode for carrying out the invention and the drawings to be described later are added in parentheses for reference, but the constituent elements of the present invention are not limited to those added.

The walking test apparatus according to means 1 is:
Measurement to measure respiratory system items (respiration rate, tidal volume equivalent, minute ventilation equivalent, arterial oxygen saturation) and circulatory system items (pulse rate, arterial oxygen saturation) during walking of the subject A walking test apparatus (1) comprising means (flow sensor 150, nostril cannula 180, face mask 190, pressure sensor 104, SpO ₂ module 106, CPU 110),
Display means for displaying the change over time of the measurement value related to the respiratory system item and the change over time of the measurement value related to the circulatory system item in a comparable manner (displaying time-series data of each item on a common time axis graph) (LCD 132 with a touch panel) is further provided.
According to this, the state of the measurement subject in the walking test can be quantitatively evaluated, and the movement limiting factor can be estimated.

The walking test apparatus according to means 2 is:
A walking test apparatus described in means 1, wherein
The first time point (the inflection point at which the slope decreases and becomes flat) where the change over time of the measurement value related to the respiratory system item falls within the first predetermined range is specified, and the measurement value related to the cardiovascular system item A specifying unit (CPU 110) for specifying a second time point (an inflection point at which the inclination decreases and becomes flat) when the change with time is in the second predetermined range;
The display means displays the anteroposterior relationship between the first time point and the second time point so as to be grasped (coordinates on the time axis (X axis) can be grasped).
According to this, an exercise | movement limiting factor can be estimated easily.

The walking test apparatus according to means 3 is:
A walking test apparatus described in means 2,
A determination unit (CPU 110) for determining whether the exercise limiting factor is a respiratory system or a circulatory system based on the context between the first time point and the second time point;
The display means displays the exercise limiting factor discriminated by the discriminating means so as to be grasped.
According to this, an exercise limiting factor can be grasped.

The walking test apparatus according to means 4 is:
A walking test apparatus described in means 3,
The determining means determines that the exercise limiting factor is a respiratory system based on the fact that the first time point is earlier than the second time point.
According to this, it can be understood that the exercise limiting factor is the respiratory system.

The walking test apparatus according to means 5 is:
A walking test apparatus described in means 3,
The discrimination means discriminates that the movement limiting factor is a circulatory system based on the fact that the second time point is earlier than the first time point.
According to this, it can be understood that the movement limiting factor is the circulatory system.

The walking test apparatus according to means 6 is:
A walking test apparatus described in means 3,
The discriminating unit discriminates that the exercise limiting factor is a respiratory system based on the fact that the first time point is earlier than the second time point, and based on the fact that the second time point is earlier than the first time point. It is characterized by discriminating that the movement limiting factor is the circulatory system.
According to this, it is possible to grasp whether the exercise limiting factor is the respiratory system or the circulatory system.

A walking test apparatus described in means 6,
The discrimination means discriminates that the exercise limiting factor is a muscle force system when neither the first time point nor the second time point is specified.
According to this, an exercise | movement limiting factor can be estimated easily.

The walking test apparatus according to means 8 is:
A walking test apparatus described in means 3,
The measuring means measures one or more items selected from the respiratory frequency and the ventilation volume (equivalent to tidal volume, equivalent to minute ventilation) as the respiratory system measurement item, and the pulse rate as the circulatory system measurement item Is measured.
According to this, it is possible to estimate the exercise limiting factor based on the items that can be easily measured from the measurement subject.

The walking test apparatus according to means 9 is:
A walking test apparatus described in means 3,
The measuring means measures the respiratory frequency and the ventilation volume (equivalent to tidal volume, equivalent to minute ventilation) as the respiratory system measurement items,
The display means displays the relationship between the number of breaths and the ventilation volume so as to be grasped.
According to this, it is possible to appropriately evaluate the respiratory function of the measurement subject.

The walking test apparatus according to means 10 is:
A walking test apparatus described in means 3,
The measuring means measures a plurality of items selected from the respiratory frequency, ventilation volume (equivalent to tidal volume, equivalent to minute ventilation), and arterial oxygen saturation as the respiratory system measurement items,
The display means displays the measured changes over time of each respiratory system item so that they can be compared.
According to this, it is possible to appropriately evaluate the respiratory function of the measurement subject. Here, the term “ventilation” simply refers to tidal and minute ventilation that can be measured by using a differential pressure flow sensor, and tidal volume that can be measured by using a nostril cannula or a face mask. It is a concept that includes all equivalent and equivalent minute ventilation.

The walking test apparatus according to means 11 is:
A walking test apparatus described in means 3,
Classifying means (CPU 110) for classifying the respiratory function tendency (respiratory function type) of the person to be measured based on the change over time of the measured value of the respiratory system item,
The display means displays the classified respiratory function tendency.
According to this, it is possible to appropriately classify the respiratory function tendency of the measurement subject and notify the measurement subject.

The walking test apparatus according to means 12 is:
A walking test apparatus described in means 11, wherein
The measuring means measures the respiratory rate and the ventilation volume as the respiratory system item,
The classifying means classifies the respiratory function tendency (respiration rate compensation type, ventilation rate compensation type, mixed type) based on a change with time in the measured value of the respiratory rate and the ventilation rate.
According to this, it is possible to appropriately classify the respiratory function tendency based on the temporal change of the measured value of the number of breaths and the ventilation volume.

The walking test apparatus according to means 13 is:
A walking test apparatus described in means 12, comprising:
The measuring means measures an IE ratio as the respiratory system item,
The classification means classifies the respiratory function tendency (IE ratio change type) based on a change with time of the IE ratio.
According to this, it is possible to appropriately classify the respiratory function tendency based on the temporal change of the IE ratio.

The walking test apparatus according to means 14 is:
A walking test apparatus described in means 3,
The measurement means measures a respiratory system item and a circulatory system item of a measurement subject in a pre-rest state before starting the walking test and a post-rest state after finishing the walking test,
Recovery status determination means (CPU 110) for determining the recovery status (recovery coefficient, recovery time) of the measurement value of each item in the rear rest state relative to the previous rest state,
The determination means displays the determined recovery status.
According to this, it is possible to determine the health condition and the pathological condition of the measurement subject by determining the recovery status of the measured values of each item in the post-rest state relative to the pre-rest state. Further, the determination result can be notified.

The walking test apparatus according to means 15 is:
A walking test apparatus described in means 3,
The measuring means further measures various walking quantities including at least one of the walking distance, walking speed, and position of the measurement subject during the walking test (CPU 110, inertial sensor, acceleration / geomagnetic sensor 105, gyro sensor). , GPS sensor, IMU, INS),
The measured walking quantities are displayed.
According to this, it is possible to notify the measurement subject of various walking amounts of the measurement subject during the walking test.

The walking test apparatus according to means 16 is:
A walking test apparatus described in means 15,
The measurement means includes an acceleration sensor (3-axis acceleration sensor) and an orientation sensor (3-axis geomagnetic sensor) (acceleration / geomagnetic sensor 105), and the measurement subject's measurement results are detected based on the detection results of the acceleration sensor and the orientation sensor. The walking distance is measured as the various walking quantities.
According to this, the walking distance of the measurement subject during the walking test can be accurately measured.

The walking test apparatus according to means 17 is:
A walking test apparatus described in means 3,
A pressure port (luer connector 142, 143) to which the flow sensor (150) can be connected;
A nostril cannula or a face mask can be connected to the pressure port (luer connector 142) instead of the flow sensor.
The measurement means is capable of measuring one or more items selected from respiratory flow rate and ventilation volume when a flow sensor is connected to the pressure port (luer connectors 142, 143),
When a nostril cannula (180) or a face mask (190) is connected to the pressure port (luer connector 142), one or more items selected from respiratory pressure, respiratory rate, and ventilation volume can be measured. Features.
According to this, different devices can be selectively connected to the common pressure port, and respiratory system items corresponding to the devices connected to the pressure port can be measured.

The walking test apparatus according to means 18 is:
A walking test apparatus described in means 17, comprising:
The nostril cannula (180) is provided with an oxygen path for supplying oxygen from the oxygen supply means (oxygen supply device) to the measurement subject, in addition to the expiration path through which the measurement subject's exhalation passes. And
According to this, the walking test can be performed while supplying oxygen to the measurement subject.

The walking test apparatus described in means 19 is:
A walking test apparatus described in means 1, wherein
Determines whether the set oxygen flow set in the oxygen supply means (oxygen supply device) that supplies oxygen to the subject is appropriate based on the respiratory data (respiratory pressure waveform) of the subject. And an appropriate determination means (CPU 110) for notifying that when the determination result is a negative determination.
According to this, alerting can be performed when the set oxygen flow rate set for the oxygen supply means is not appropriate.

The walking test apparatus described in means 20 is:
A walking test apparatus described in means 19, comprising:
The appropriateness determination means performs an appropriateness determination based on a measured offset value in a measurement subject's respiratory data (respiration pressure waveform), which is an offset value of pressure based on an oxygen flow rate.
According to this, it is possible to accurately and reliably determine whether or not the set oxygen flow rate set for the oxygen supply means is appropriate.

The walking test apparatus described in means 21 is:
A walking test apparatus described in means 1, wherein
During the walking test, the apparatus further comprises an abnormality detection means (CPU 110) for detecting an abnormality in oxygen supply from the oxygen supply means for supplying oxygen to the measurement subject to the measurement subject based on the respiratory data of the measurement subject. When abnormality is detected, the fact is notified.
According to this, it is possible to detect an abnormality in the oxygen supply from the oxygen supply means to the measurement subject during the walking test and call attention.

The walking test apparatus described in the means 22 is
A walking test apparatus described in means 21, comprising:
The abnormality detecting means detects an abnormality based on a measurement offset value in a measurement subject's respiratory data, which is an offset value of a pressure due to an oxygen flow rate and is measured during a walking test.
According to this, it is possible to appropriately detect an abnormality in the flow rate of oxygen supplied from the oxygen supply means.

FIG. 1 shows a modified Borg scale. FIG. 2 is a functional block diagram showing an example of a 6-minute walking test apparatus. FIG. 3 is a view showing the appearance of the main body. FIG. 4 is a diagram showing the appearance of the flow sensor. FIG. 5 is a diagram showing the appearance of the nostril cannula. FIG. 6 is a view showing an example of the structure of the insertion tube. FIG. 7 is a view showing an example of the structure of the insertion tube. FIG. 8 is a graph showing time transitions corresponding to pulse rate, number of breaths, minute ventilation, and tidal volume. FIG. 9 is a graph showing time transitions corresponding to the pulse rate, the number of breaths, the minute ventilation, and the tidal volume. FIG. 10 is a graph showing time transitions corresponding to the pulse rate, the number of breaths, the minute ventilation, and the tidal volume. FIG. 11 is a graph showing the relationship between the number of breaths and the equivalent to tidal volume. FIG. 12 is a graph showing the relationship between the number of breaths and the equivalent to minute ventilation. FIG. 13 is a diagram showing the dip angle distribution. FIG. 14 is a diagram showing the relationship between the geomagnetic direction in the standard posture and the geomagnetic direction in the walking posture. FIG. 15 is a diagram showing measurement results of a 6-minute walking test. FIG. 16 is a diagram showing a BODE index. It is a figure which shows an example of the system configuration | structure of a walking test system. It is a flowchart which shows the flow of a respiratory function type determination process. It is explanatory drawing of the determination method of a respiratory function type. It is a flowchart which shows the flow of the determination process before a walk test (after a walk test). It is a flowchart which shows the flow of a determination process. It is a flowchart which shows the flow of the determination process during a walk test.

Hereinafter, the 6-minute walking test apparatus 1 which is an example of the walking test apparatus according to the present invention will be described with reference to the drawings.

[Configuration of 6-minute walking test device]
As shown in FIG. 2, the 6-minute walking test apparatus 1 according to the present embodiment includes a main body 100, a flow sensor 150 connected to the main body 100, or a nostril cannula 180 or a face mask 190 connected in place of the main body 100. It includes an SpO ₂ probe 160 and a wireless remote controller 170 that transmits a command signal and an event signal to the main body 100. Inside the main body 100, there are a receiver 101, a temperature sensor 102, a battery 103, a pressure sensor 104, an acceleration / geomagnetic sensor 105, an SpO ₂ module 106, an A / D converter 107, a CPU 110, a RAM 121, a ROM 122, and a solenoid valve 123. , And a USB driver circuit 124 is provided. As shown in FIGS. 2 and 3, the housing of the main body 100 includes luer connectors 142 and 143, an SpO ₂ connector 141, a DC jack 145, a USB connector 131, a liquid crystal with touch panel 132, a buzzer 133, and an LED 134. I have.

The pressure sensor 104 has two pressure ports for detecting pressure, and each pressure port has polarity. A positive voltage is output when a positive pressure is applied to one pressure port, and a negative voltage is output when a positive pressure is applied to the other pressure port. The pressure sensor 104 in this example is a differential pressure sensor, and outputs an analog signal proportional to the differential pressure between both pressure ports. A luer connector 142 is connected to one pressure port, and a luer connector 143 is connected to the other pressure port. The pressure sensor 104 includes an output terminal for detecting a differential pressure between the luer connectors 142 and 143 and outputting a voltage proportional to the detected differential pressure.

In the example shown in FIG. 3, when exhalation is applied from the luer connector 142, a negative voltage is output from the output terminal of the pressure sensor 104, and when exhalation is applied from the luer connector 143, the pressure sensor A positive voltage is output from the output terminal 104. This corresponds to the fact that, during a respiratory function test, exhalation is generally displayed as a negative value (volume decrease) and inspiration is displayed as a positive value (volume increase).

The A / D converter 107 is provided with an A / D converter corresponding to the output of the pressure sensor 104, whereby a differential pressure converted from an analog signal to a digital signal is read by the CPU 110, and based on the differential pressure. Thus, the calculation of the respiratory flow rate and the respiratory volume is executed.

The flow sensor 150 will be described in detail with reference to FIG. A connection port 152 for connecting a filter and a mouthpiece is provided on a side surface of the flow sensor case 151 serving as a housing of the flow sensor 150. A handle 156 for holding the flow sensor case 151 is provided below the flow sensor case 151.

In the flow tube 153 in the flow sensor case 151, a screen 155 is disposed as a resistor that generates respiratory resistance. The screen 155 is a mesh-like material and is arranged so as to block the gas flow. When a gas flow occurs in the flow tube 153, a differential pressure is generated before and after the screen 155. The pressure before and after the screen 155 is transmitted to the luer connectors 142 and 143 of the main body 100 via the tubes 157 and 158 connected to the pressure ports arranged at the front and rear of the screen 155, respectively. ing. That is, out of the two tubes 157 and 158 constituting the differential pressure tube, the tube 157 transmits the pressure in front of the screen (on the connection port 152 side) to one luer connector 142 connected to the tube terminal 157a. Transmits the pressure behind the screen to the other luer connector 143 connected to the tube terminal 158a. On the main body 100 side (pressure sensor 104), the flow rate of the gas flowing in the flow tube 153, that is, the respiratory flow rate, can be measured by detecting the differential pressure between these two luer connectors. This respiratory flow rate is also called a respiratory flow rate. Note that this type of flow sensor is a so-called differential pressure type and is widely used.

When the flow sensor 150 is connected to the luer connectors 142 and 143, the measured pressure is detected by the CPU 110 when the person under test breathes in a state where the mouthpiece connected to the connection port 152 is fixed to the mouth. A respiratory flow rate (hereinafter sometimes referred to as “flow”) is calculated, and a respiratory volume (hereinafter also referred to as “volume”) is calculated by integrating the respiratory flow rate. In addition, the person to be measured holds the mouthpiece so that there is no gap, and breathes in a state where the nose grip is attached (a state in which nasal breathing is not possible). be able to. The flow and volume measured in this way are read by the CPU 110, and based on the measured value, the vital capacity (FVC), 1 second amount (FEV1), 1 second rate (FEV1%),% 1 second amount (% FEV1) and the like are calculated. Each measured value thus obtained is displayed on the liquid crystal 132 with a touch panel.

Also, by connecting the flow sensor 150 to the main body 100, it is possible to measure the tidal volume and minute ventilation of the person being measured. As described above, the flow can be calculated based on the differential pressure, and the tidal volume and minute ventilation can be calculated by time integration of the flow. The tidal volume is a ventilation volume per exhalation or inspiration, and the exhalation tidal volume is calculated based on the exhalation flow, and the inhalation tidal volume is calculated based on the inspiration flow. The minute ventilation is the ventilation per minute.

Here, although the flow sensor 150 can be used when the measurement subject is in a resting state, there is a problem that the flow sensor 150 cannot be used while walking. This is because it is difficult to perform measurement while walking while holding the mouthpiece connected to the connection port 152 while walking. In addition, if measurement is performed in such a state, since the volume in the flow tube 153 including the mouthpiece is large, exhalation stays in the flow sensor from the mouthpiece, and the carbon dioxide concentration in the space increases. This is because breathing cannot be continued.

Therefore, after measuring the above-described forced vital capacity (FVC) and 1-second amount (FEV1) using the flow sensor 150 before the start of walking, the flow sensor 150 is removed from the luer connectors 142 and 143 and shown in FIG. The terminal 181a of the shown nostril cannula 180 is connected to the luer connector 142 (that is, a port to which a negative voltage is output when exhalation is applied) to capture exhalation / inspiration of the measurement subject.

The nostril cannula 180 in the present embodiment is a soft tube made of vinyl chloride, and as shown in FIG. 5, as shown in FIG. 5, a stem pipe 181, a right branch pipe 182 and a left branch pipe 183 branched from a branch portion of the trunk pipe 181, and The right branch tube 182 and the left branch tube 183 are connected to each other at a position opposite to the branch portion, and the right insertion tube 186 inserted into the subject's right nostril and the left insertion tube 187 inserted into the subject's left nostril. The mounting member 185 is provided. The trunk pipe 181 is provided with one tube terminal 181a, which is different from the flow sensor 150 having two terminals.

An annular shape body is formed by the right branch pipe 182 and the left branch pipe 183 branched from the trunk pipe 181 and the mounting member 185 connecting them. The subject passes the head through the ring-shaped body, puts the right branch tube 182 over the right ear, puts the left branch tube 183 over the left ear, and further inserts the right insertion tube 186 into the right nostril. Walk with 187 inserted into the left nostril. By doing so, there is no restriction like the flow sensor 150 that needs to breathe with the mouthpiece held, and it also feels difficult to breathe due to retention of exhaled breath (carbon dioxide) and weight when wearing it. In addition, the measurement subject can comfortably perform the walking test.

Here, when the tube terminal 181a provided in the trunk tube 181 of the nostril cannula 180 is connected to the luer connector 142, the remaining luer connector 143 is opened to the atmosphere. Therefore, in the pressure sensor 104, the atmospheric pressure and the inside of the trunk tube 181 A differential pressure from the pressure is detected. The differential pressure measured in this way is read by the CPU 110, and the number of breaths to be described later is calculated based on the fluctuation of the differential pressure. Each measured value thus obtained is displayed on the liquid crystal 132 with a touch panel.

Here, when the nostril cannula 180 is used, the respiratory pressure at the luer connector 142 is detected with the luer connector 143 opened to the atmosphere. Since the total amount of inspiration cannot be captured, the flow cannot be measured accurately. However, it is possible to capture changes in respiratory pressure even with one port.

Specifically, assuming that the sensitivity of the pressure measurement on the expiration side and the inspiration side is the same at one port to which the nostril cannula is connected, the offset correction is executed with respect to the reference level of the measured respiratory pressure. . For example, if the measured value of respiratory pressure at a certain reference level is 10 (absolute value) on the expiration side, but 8 (absolute value) on the inspiration side, the values on the expiration side and inspiration side are the same ( In other words, offset adjustment is performed by shifting the reference level by 1 (absolute value) toward the expiration side so that the expiration amount and the inspiration amount are the same. Then, 9 (absolute value) on the exhalation side and 9 (absolute value) on the inhalation side become the same value. The respiration pressure at the reference level after the offset correction is hereinafter referred to as a flow equivalent, and is distinguished from the flow described above.

∙ Tidal volume equivalent and minute ventilation equivalent can be calculated by time integration equivalent to flow. The tidal volume equivalent is the ventilation volume per exhalation or inspiration for the flow equivalent, and the equivalent to the exhalation tidal volume is calculated based on the exhalation flow, and the equivalent to the inspiratory tidal volume based on the inspiratory flow Is calculated. The minute ventilation equivalent is the ventilation per minute for the flow equivalent.

Unlike the case where the flow sensor 150 is used, since the tidal volume and the minute ventilation are measured based on the respiratory pressure obtained under conditions where the flow cannot be measured accurately, The tidal volume measured under such conditions is referred to as “equivalent to tidal volume”, and the minute ventilation is referred to as “equivalent to minute ventilation”. In this embodiment, when simply saying “ventilation volume”, the tidal volume and minute ventilation volume that can be measured with the flow sensor 150 connected, and the nostril cannula 180 (or the face mask 190 described later). It is a concept that includes all of the equivalent to tidal volume and minute ventilation that can be measured in the state where is connected.

Here, when a walking test is performed while supplying oxygen to the subject, a nostril cannula as shown in FIG. 6 or 7 is preferably used. Such nostril cannula is called a dual lumen cannula and is composed of two tubes. For example, as shown in FIG. 6, an inner tube 186a whose cross section is concentric with the right insertion tube 186 and an inner tube 187a whose cross section is concentric with the left insertion tube 187 are provided, and the inner tubes 186a and 187a are It is an oxygen supply tube connected to an oxygen cylinder or oxygen concentrator. As a result, oxygen is supplied from the inner tubes 186a and 187a to the subject. The right insertion tube 186 and the left insertion tube 187 are connected to a respiratory pressure detection tube connected to the luer connector 142 of the main body 100. Accordingly, it is possible to measure the number of breaths and the ventilation volume while supplying oxygen to the measurement subject, and it is also possible to perform a walking test on the measurement subject performing HOT.

In the example shown in FIG. 7, a wall portion 186b that divides the cross section of the right insertion tube 186 into two regions and a wall portion 187b that divides the cross section of the left insertion tube 187 into two regions are provided. One region divided by the wall portion 186b and the wall portion 187b is connected to an oxygen supply tube connected to an oxygen cylinder or an oxygen concentrator. Further, the other region divided by the wall portion 186 b and the wall portion 187 b is connected to a respiratory pressure detection tube connected to the luer connector 142 of the main body portion 100. Accordingly, it is possible to measure the number of breaths and the ventilation volume while supplying oxygen to the measurement subject, and it is also possible to perform a walking test on the measurement subject performing HOT.

The SpO ₂ probe 160 is a transducer attached to the fingertip of the person to be measured, and includes a light emitting unit and a light receiving unit (sensor). The light emitting unit emits red light and infrared light, and the light receiving unit (sensor) measures the amount of light transmitted through the fingertip (or the amount of light reflected by the fingertip) and outputs it as an electrical signal. To do. The SpO ₂ probe 160 is connected to the SpO ₂ connector 141 of the main body 100 shown in FIG. The SpO ₂ module 106 includes an A / D converter that converts an analog signal output from the SpO ₂ probe 160 into a digital signal. SpO ₂ is calculated based on the transmitted light amount (or reflected light amount) of each light, and a pulse wave signal is generated and each is output as an electrical signal. The CPU 110 counts the pulse rate based on the pulse wave signal with pulsation output from the SpO ₂ module 106. The SpO ₂ and pulse rate measured in this way are stored in the RAM 121 by the CPU 110 and displayed on the liquid crystal 132 with a touch panel.

The wireless remote controller 170 is, for example, a wireless remote controller provided with a plurality of buttons, and a signal corresponding to the operated button is output. For example, the receiving unit 101 down-converts the received signal, performs A / D conversion, and outputs the signal to the CPU 110 in a predetermined format. The CPU 110 executes control according to the output signal. For example, the wireless remote controller 170 is provided with an event button and a display switching button according to the test status and the condition of the subject. For example, when an event button of “measurement start” is operated, the CPU 110 that has received a signal corresponding to the event button displays a message “please rest and rest” on the liquid crystal 132 with a touch panel, so that the subject is measured. Encourage them to take a rest breath. When the display switching button is operated, the display content of the liquid crystal 132 with a touch panel is switched.

The temperature sensor 102 measures the temperature inside the main body 100, and is, for example, a diode type temperature sensor capable of measuring the temperature based on the forward voltage of the diode. The A / D converter 107 is provided with an A / D converter corresponding to the output of the temperature sensor 102, whereby a voltage value converted from an analog signal to a digital signal is read by the CPU 110, and the voltage value is converted into the voltage value. The corresponding temperature is calculated. The temperature measured in this manner is stored in the RAM 121 and displayed on the liquid crystal 132 with a touch panel.

The battery 103 is a dry battery in the present embodiment, and is one of power supply means to the main body 100. The A / D converter 107 is provided with an A / D converter corresponding to the bipolar voltage of the battery 103, whereby a voltage value converted from an analog signal to a digital signal is read by the CPU 110, and the voltage value is converted into the voltage value. The approximate remaining amount is determined (for example, the remaining amount is “high” or “low”). The remaining amount determined in this way is stored in the RAM 121 and displayed on the liquid crystal 132 with a touch panel. In this embodiment, as shown in FIG. 3, the main body 100 is provided with a DC jack 145, and power is supplied to the main body 100 from a household power source via an AC / DC adapter. Is possible. In addition, power can be supplied to the main body 100 from a USB connector 131 described later, which is a so-called three power supply type device.

The acceleration / geomagnetic sensor 105 is a 6-axis sensor in which a 3-axis acceleration sensor and a 3-axis geomagnetic sensor are integrated. The triaxial acceleration sensor outputs a voltage corresponding to each acceleration in the triaxial direction, and the triaxial geomagnetic sensor outputs a voltage corresponding to the local magnetism in the triaxial direction. The A / D converter 107 is provided with an A / D converter corresponding to the six-axis voltage of the acceleration / geomagnetic sensor 105, whereby a voltage value converted from an analog signal to a digital signal is read by the CPU 110. . The acceleration in the triaxial direction measured in this way and the geomagnetism in the triaxial direction are stored in the RAM 121 and displayed on the liquid crystal 132 with a touch panel. A module in which an A / D converter is incorporated in such a 6-axis sensor may be used. Moreover, CPU110 can calculate a to-be-measured person's walking distance based on the output of a triaxial acceleration sensor and the output of a triaxial geomagnetic sensor so that it may mention later. In this embodiment, a 6-axis sensor in which a 3-axis acceleration sensor and a 3-axis geomagnetic sensor are integrated is used, but in addition to the 3-axis acceleration sensor and the 3-axis geomagnetic sensor, an angular velocity sensor is also integrated. Alternatively, a 9-axis sensor may be used.

The CPU 110 executes a 6-minute walking test program stored in the ROM 122 by using the RAM 121 as a work area, thereby controlling the operation of each connected component or receiving a signal from each component. The process is performed. Each data measured in the 6-minute walking test is accumulated in the RAM 121. When the 6-minute walking test is completed, the data accumulated in the RAM 121 is stored in the ROM 122.

The ROM 122, which is a non-volatile memory, stores measurement data as described above, and also stores measurement programs such as a 6-minute walking test program. The electromagnetic valve 123 is driven by the CPU 110 via a transistor switch (not shown). In the present embodiment, the electromagnetic valve 123 is connected to the pressure sensor 104, and the pressure sensor 104 measures the atmospheric pressure when the electromagnetic valve 123 is opened, thereby performing zero point correction.

The USB connector 131 shown in FIGS. 2 and 3 is connected to a USB connector of a host device such as the PC 2 and serves as an interface with the upper device. The USB driver circuit 124 controls communication with the host device and the CPU 110 connected by the USB connector 131. For example, it detects that a host device is connected to the USB connector 131 and transmits a command corresponding to this to the CPU 110. Along with this, the CPU 110 outputs the measurement data stored in the ROM 122 to the USB driver circuit 124, and the USB１２４ driver circuit 124 converts the input measurement data into a signal conforming to the USB standard and transmits it to the host device. To do. In this way, measurement data can be transferred to a host device such as the PC 2 via the USB interface. In addition, power can be supplied to the main body 100 from a host device connected to the USB connector 131.

The liquid crystal 132 with a touch panel is, for example, a touch panel liquid crystal module in which a TFT liquid crystal and a 4-wire resistive touch panel are integrated. When the touch panel is touched, the X-axis resistance film and the Y-axis resistance film come into contact with each other, and a signal corresponding to the resistance at the contact location is output. In this embodiment, the liquid crystal 132 with a touch panel is of a module type including an A / D converter, and an X-axis signal and a Y-axis signal indicating contact coordinates are input as digital signals to the CPU 110, and according to the contact coordinates. Processing is executed. Measurement data in the 6-minute walk test is displayed on the TFT liquid crystal.

The buzzer 133 performs notification by outputting a predetermined buzzer sound. For example, the buzzer 133 emits a buzzer sound according to the state of the measurement subject. The LED 134 performs notification by being turned on or blinking in a predetermined manner. For example, the LED 134 is lit or blinked in a manner according to the state of the walking test apparatus. The sound output control of the buzzer 133 and the lighting / flashing control of the LED 134 are performed by the CPU 110. The speaker 135 is connected to the CPU 110 via a voice control board (not shown) that is a control board for voice output control. The audio control board is equipped with a processing circuit that executes audio signal processing for outputting audio from the speaker 135 based on control data from the CPU 110. *

[Execution of 6-minute walking test program]
(Measurement before starting walking)
Prior to the start of the 6-minute walking test, the age, sex, height, weight, etc. of the person to be measured are input using the liquid crystal 132 with a touch panel. Then, after connecting the flow sensor 150 to the main body 100 and confirming the resting state, the effort vital capacity (FVC), 1 second amount (FEV1), 1 second rate (FEV1%),% 1 second amount (% FEV1) Measure etc. The predicted value for the amount of 1 second is calculated based on the formula stored in advance in the program and the input data. Further, the SpO ₂ probe 160 is attached to the fingertip of the person to be measured, and SpO ₂ and the pulse rate before the start of walking are measured. Furthermore, the blood pressure is also measured in order to confirm the systolic and diastolic phases by checking with the modified Borg scale.

(Measurement during walking)
Next, the flow sensor 150 is removed from the main body 100, and instead of this, a nostril cannula 180 is connected and attached to the subject. Further, the SpO ₂ probe 160 is attached to the fingertip of the measurement subject. After both devices are mounted, the “measurement start” button provided on the wireless remote controller 170 is operated while power is supplied to the main unit 100, or the “measurement start” icon displayed on the liquid crystal 132 with a touch panel When is touched, execution of the walking test program for 6 minutes is started. Accordingly, the CPU 110 displays a message “please rest and breathe” on the liquid crystal 132 with a touch panel to prompt the subject to be at rest and to check whether or not the rest is being ventilated. . For example, when the smoothed respiratory pressure differential value is switched from positive to negative (or from negative to positive) within a certain range (for example, a range of 5 to 10 seconds) for a predetermined number of times. Ventilation has been confirmed.

When the CPU 110 confirms that the ventilation at rest is performed and that the SpO ₂ is within the preset range, the CPU 110 displays a message “The test can be started” and notifies the measurer that the test can be started. Then, after confirming the condition of the subject, the measurer tells the subject that “Please start walking when you are ready”. When the measurer operates the “walk start” button provided on the wireless remote controller 170 at the time when the person to be measured starts walking, the CPU 110 that has received the corresponding signal starts counting for 6 minutes. . Along with this, each item such as the number of breaths, the amount corresponding to the tidal volume, and the amount corresponding to the minute ventilation is measured based on the detected respiratory pressure. Further, recording of SpO ₂ is started based on the output of the SpO ₂ probe 160. Further, the number of steps, the walking speed, and the walking distance are measured based on the output of the acceleration / geomagnetic sensor 105. A method for measuring these walking data will be described later.

In the case where SpO ₂ of the subject falls below or a predetermined value when decreases more than a predetermined width, by buzzer sound from the buzzer 133 is output, that is SpO ₂ of the subject is not a good value Is notified. As a result, the medical staff can determine the necessity of stopping the walking test or taking a break. For example, a subject undergoing home oxygen therapy is usually in a state where oxygen gas is being supplied, but in an air environment where oxygen gas is not supplied in a respiratory function test, Measurements may be performed at low oxygen concentrations. Furthermore, in the respiratory function test, when the forced vital capacity or the like is measured, the patient is forced to perform breathing that requires more effort than normal breathing, which is a heavy burden. In such a case, it is possible to determine whether or not an excessive burden has occurred by using SpO ₂ and warn with a buzzer sound so that the measurement subject does not fall into a dangerous state. In addition, even when a walking test is performed in a state where oxygen gas is supplied to the subject to be measured through a dual lumen cannula or face mask from an oxygen cylinder or the like, the oxygen gas is not properly supplied due to twisting of the tube or improper mounting. There is a case. Even in such a case, it is possible to prevent danger by detecting a decrease in SpO ₂ and warning with a buzzer sound.

In addition, the 6-minute walking test apparatus 1 is configured to be able to speak to the measurement subject via the speaker 135 during the walking test. Specifically, for example, during a 6-minute walking test, the subject is informed of the subject's walking state and physical state at that time (for example, “successfully walking”). Walking with a purpose of notifying the person being measured about the remaining time of the walking test (for example, “Remaining time is x minutes”) Support processing may be executed.

In this case, in order to make it easier for the measurement subject to grasp the timing of the voice call, for example, the voice call may be performed at a predetermined time interval (preferably a timing of one minute) during the walking test. In addition, when a test subject is notified by sounding or outputting a beep sound that the end of the walking test is approaching at a certain time before the end of the walking test (preferably a timing of 15 seconds before). Good. In addition, when calling out the content indicating the remaining time of the walking test, the “×” part of “Remaining time is x minutes”, that is, the number part indicating the remaining time (minutes) until the end of the walking test The above message may be output as a sound by changing only the voice.

In addition, as the above-mentioned walking support processing, control is performed such as outputting sound prompting walking at a constant rhythm or outputting beep sounds at regular time intervals so as to encourage walking at a constant rhythm. It is good.

In addition, the 6-minute walking test apparatus 1 can interrupt the walking test to the person to be measured when the measured value of the circulatory system item or the respiratory system item becomes a value indicating a dangerous state during the walking test. It is configured to be able to perform an alerting notification process that prompts cancellation. Specifically, for example, when SpO ₂ falls below a predetermined lower limit, when the pulse rate exceeds a predetermined upper limit, or when the number of breaths exceeds a predetermined upper limit, an alarm or warning sound If the walking test is continued any more, for example, by outputting a warning voice, the person to be measured is informed that it is dangerous.

“Number of breaths” (also referred to as RR) is the number of breaths of the subject in one minute, and by counting the number of times the differential value of the smoothed breathing pressure is switched from positive to negative (or from negative to positive) Measured. The “tidal volume” (also referred to as VT) is the ventilation volume per breath at rest, and is calculated as an integrated value of the respiratory pressure in one breath. However, in this embodiment, as described above, when using the nostril cannula 180, “equivalent to tidal volume” is calculated. Further, the “minute ventilation” (also referred to as TE) is a ventilation volume per minute at rest, and is calculated as “tidal volume” × “respiration frequency”. However, in this embodiment, as described above, “equivalent minute ventilation” is calculated when the nostril cannula 180 is used.

Further, since the pulse wave waveform (time-series data) can be constructed in the CPU 110 based on the output of the SpO ₂ probe 160, the “pulse rate” can be calculated based on this. “Pulse rate” is the pulse rate of the person to be measured in 1 minute, and after smoothing the time series data of the pulse wave, counting the number of times the differential value switches from positive to negative (or from negative to positive) Measured.

The respiratory frequency, tidal volume equivalent, minute ventilation equivalent, and pulse rate measured in this way are recorded as time-series data as shown in FIGS. Is displayed in graph format. In the examples of FIGS. 8 to 10, the elapsed time from the start of the gait test is the common X axis, and the Y axis is the measurement of each item of the respiratory rate, the tidal volume equivalent, the minute ventilation quantity, and the pulse rate. It is displayed in a graph format corresponding to the value. In this way, by displaying the number of breaths, equivalent to tidal volume, equivalent to minute ventilation, and pulse rate in a manner that can be compared with the elapsed time from the start of the walking test as a reference, items related to respiratory function A certain number of breaths, equivalent to tidal volume, and equivalent to minute ventilation can be compared with the time transition of the pulse rate, which is an item related to the circulatory function. As a result, the following determination can be performed.

First, in the example of FIG. 8, with the passage of time from the start of measurement, the increase in the number of breaths, equivalent to the minute ventilation, and the equivalent to the tidal volume become gentle (after 3 minutes), and then the pulse rate rises Is moderate (after 4 minutes). In other words, the respiratory rate, minute ventilation, and tidal volume, which are respiratory items, reach a peak earlier than the pulse rate, which is a cardiovascular item, so It is possible to estimate an event that the function of the respiratory system does not catch up with the increase, and as a result the walking distance is suppressed. Thus, it is possible to quantitatively evaluate the state of the person being measured in the walking test, and to estimate that the movement limiting factor is in the respiratory system.

In the example of FIG. 9, the pulse rate first increases gradually with the passage of time from the start of measurement (after 2 minutes), and then the number of breaths, equivalent to minute ventilation, and equivalent to tidal volume The rise is slow (after 3 minutes). In other words, the pulse rate, which is a circulatory system item, reaches a peak earlier than the respiratory rate, which corresponds to the respiratory system item, the equivalent to minute ventilation, and the equivalent to tidal volume. It is possible to estimate an event that the function of the circulatory system does not catch up with the increase, and as a result the walking distance is suppressed. Thus, it is possible to quantitatively evaluate the state of the measurement subject in the walking test, and to estimate that the movement limiting factor is in the circulatory system.

Further, in the example of FIG. 10, with the passage of time from the start of measurement, the pulse rate, the number of breaths, the equivalent to minute ventilation, and the equivalent to tidal volume continuously increase, and FIG. 8 and FIG. It is not possible to clearly grasp the time when the rise has become gradual as in the example. That is, if the respiratory rate, respiratory rate, minute ventilation, and tidal volume, and the circulatory rate, pulse rate, do not peak, but the walking distance is short Can estimate the phenomenon that the function of the muscular strength system does not catch up with the increase in the amount of exercise, and as a result the walking distance is suppressed. In this way, the state of the measurement subject in the walking test can be quantitatively evaluated, and it can be estimated that the exercise limiting factor is in the muscular strength system.

(Calculation of inflection points)
As shown in FIG. 8 to FIG. 10, the time transition of each item of the respiratory system and the circulatory system is displayed in a graph with a common time axis, so that the walking distance of the measured person can be changed to the respiratory system and the circulatory system. It can be estimated whether it is suppressed by a factor of the muscle strength system, but for example, by calculating the inflection point of each item based on the following steps, to grasp the movement limiting factor more clearly Is possible.

(1) Initialization of variables: An inclination change flag (Ang = 0) and an inclination change continuation counter (Cnt = 0) are initialized.
(2) Calculation of moving average: Tv (m) is m-th data, and the average of five data from Tv (m-4) to Tv (m) is moving average Av (n). Av (n) is represented by the following equation. n = m-4, and Av (n) can be calculated from Tv (5) onward.

(3) Inclination change flag set / non-set: The difference between Av (n-1) and Av (n) is D (n), and D (n) is 3% or less, that is, the following conditions are met: Is set with an inclination change flag (Ang = 1). When the following conditions are not satisfied, the inclination change flag is not set (Ang = 0).

(4) Count when tilt change flag is set / not set: Calculate (2) and (3) based on Tv (m + 1) measured next (Av (n + 1), D (n + 1)). If the inclination change flag is set (Ang = 1), the inclination change continuation counter Cnt is updated by 1 (Cnt = Cnt + 1). If the inclination change flag is not set (Ang = 0), the inclination change continuation counter Cnt is updated by 1 (Cnt = Cnt-1).
(5) Flatness determination: When (2), (3), and (4) are calculated based on Tv measured after that, and the slope change continuation counter reaches a certain value (for example, when Cnt = 5), In other words, if the state where the rate of increase or decrease is small continues for a predetermined time or longer, the flat flag is set (Pln = 1), the slope change continuation counter is reset (Cnt = 0), and the first measured value A linear regression line A is obtained using data from Tv (1) to Tv (n) acquired this time. At this time, n is stored as Inf = n as an inflection point.
However, since this inflection point is not the intersection of the regression lines, the intersection with the linear regression line A was obtained by drawing the linear regression line B in the flat region by the following (6), (7) and (8). Things are true inflection points.

(6) Count when the inclination change flag is set / not set: Calculations (2) and (3) are performed based on the Tv measured thereafter. If the flat flag is set (Pln = 1) and the slope change flag Ang = 0 (the slope is large), the slope change continuation counter Cnt is updated by 1 (Cnt = Cnt + 1). If the flatness flag is set (Pln = 1) and the inclination change flag Ang = 1 and the inclination change continuation counter Cnt is not 0 (Cnt> 0), the inclination change continuation counter Cnt is updated by 1 (Cnt = Cnt-1).
(7) Inclination change determination: When the inclination change continuation counter reaches a certain value (for example, when Cnt = 5), that is, when the increase rate or decrease rate continues for a predetermined time or more, the flat flag Is reset (Pln = 0), the slope change continuation counter is reset (Cnt = 0), and the linear regression line using the data from the inflection point Tv (Inf) calculated in (5) to Tv obtained this time Find B.

(8) Graph display: The linear regression line A and the linear regression line B are displayed on the graph, and the intersection of both lines is clearly displayed as an inflection point. For example, for each item, a linear regression line A related to the slope change region and a linear regression line B related to the flat region are displayed, and orthogonal to the X axis from the inflection point of each item as illustrated in FIGS. A straight line (parallel to the Y axis) is displayed, and the X coordinate of the inflection point of each item is clearly displayed. As a result, it is possible to easily confirm which item's inflection point has occurred at an early time from the start of measurement, or whether the inflection point has not occurred. It becomes easy to estimate whether it is suppressed by a factor of the circulatory system or the muscular strength system.

Here, after the graph display of (8) is performed, or instead of this, the exercise limiting factor may be displayed on the liquid crystal 132 with a touch panel. For example, in the example shown in FIG. 8, the inflection point of the respiratory system item (the number of breaths, equivalent to minute ventilation, equivalent to the tidal volume) is larger than the inflection point of the circulatory system item (pulse rate). Based on what is confirmed at an early point in time, it is recommended to display “Exercise limiting factor is respiratory system”. In the example shown in FIG. 9, the inflection point of the circulatory system item (pulse rate) is more than the inflection point of the respiratory system item (equivalent to the number of breaths, minute ventilation, equivalent to the tidal volume). Based on what is confirmed at an early point in time, it is recommended to display “Exercise-limiting factor is circulatory system”. Further, in the example shown in FIG. 10, both the inflection point of the respiratory system item (respiration frequency, equivalent to minute ventilation, equivalent to tidal volume) and the inflection point of the circulatory system item (pulse rate) are both. Since it is not allowed, it is recommended to display “Exercise-limiting factor is strength system”. This makes it easier to estimate whether the walking distance of the measurement subject is suppressed by the respiratory system, the circulatory system, or the muscular strength system.

In the example shown above, respiratory rate, respiratory rate, minute ventilation, and tidal volume are measured as respiratory system measurement items, and pulse rate is measured as a circulatory system measurement item. Items can be measured based on respiratory pressure and pulse waveform. In this manner, the exercise limiting factor can be estimated based on the items that can be easily measured from the measurement subject.

(Analysis of respiratory function)
As described above, in the 6-minute walking test apparatus 1 according to the present embodiment, as the respiratory system items, in addition to the pressure change, the number of breaths, the equivalent to the tidal volume, the equivalent to the minute ventilation, and the SpO ₂ Changes over time are measured. These measurement data can be displayed in a graph using a common time axis (X axis).

Further, in this embodiment, as shown in FIG. 11, it is possible to create a graph showing the relationship between the number of breaths and the tidal volume. In this example, a graph in which the X axis is the number of breaths and the Y axis is equivalent to a tidal volume is created and displayed on the liquid crystal 132 with a touch panel. This graph makes it possible to analyze the respiratory system as shown below.

First, as shown in FIG. 11 (A), in the case of a healthy person, the increase in the ventilation volume accompanying the amount of exercise is covered by the increase in the tidal volume, so the increase in the number of breaths is in a narrow range. In this case, the effective alveolar ventilation is high and the burden on the respiratory muscles is small. The graph shows a rising pattern (coefficient A of the linear regression line (Y = AX + B) is positive). On the other hand, as shown in FIG. 11 (B), in the case of a COPD patient, the respiratory reference level is increased due to hyperinflation, and the tidal volume is decreased. As a result, an attempt is made to maintain the ventilation volume. The number of breaths increases and the difficulty of breathing increases. In this case, the effective alveolar ventilation is low and the burden on the respiratory muscles is large. The graph shows a descending pattern (coefficient A of the linear regression line (Y = AX + B) is negative). Based on such results, the medical staff should take measures such as reducing respiratory muscle burden and improving exercise tolerance by breathing guidance such as abdominal breathing, and by improving dyspnea It can be judged that QOL (quality of life) should be improved. In this way, it is possible to determine the respiratory function of the subject by the linear regression line. For example, the coefficient A of the linear regression line (Y = AX + B) is within a predetermined range (for example, −2 ≦ A ≦ 2). In some cases, it can be assumed that there is a suspicion of COPD.

Further, in this embodiment, as shown in FIG. 12, it is possible to create a graph showing the relationship between the number of breaths and the minute ventilation. In this example, a graph in which the X axis is the number of breaths and the Y axis is equivalent to the minute ventilation is created and displayed on the liquid crystal 132 with a touch panel. This graph makes it possible to analyze the respiratory system as shown below.

First, as shown in FIG. 12 (A), in the case of a healthy person, the change in the number of breaths is small and the change corresponding to the minute ventilation is large, so the slope of the graph becomes large and the linear regression line (Y = AX + B) The value of the coefficient A increases. For example, the coefficient A is 300 or more. On the other hand, as shown in FIG. 12B, in the case of a COPD patient, the change in the number of breaths is large and the change corresponding to the minute ventilation is small, so the slope of the graph is small and linear regression is performed. The value of the coefficient A of the straight line (Y = AX + B) becomes small. For example, the coefficient A is less than 100. In this way, it is possible to determine the respiratory function of the measurement subject based on the linear regression line. For example, the coefficient A of the linear regression line (Y = AX + B) is within a predetermined range (for example, 100 ≦ A ≦ 300). In some cases, it can be assumed that COPD is suspected.

The 6-minute walking test apparatus 1 of the present embodiment, in addition to the analysis of the respiratory function as described above, determines which respiratory function type the measured person is classified from among a plurality of respiratory function types shown below. Respiratory function type classification processing is performed, and the determination result can be displayed.

FIG. 18 is a flowchart showing the flow of the respiratory function type classification process executed by the CPU 110 in this case.
First, the CPU 110 sets an evaluation period for evaluating the respiratory function type (A1). The evaluation period may be the entire period of the walking test period (walking test period) (a period of 6 minutes), or a part of the walking test period (for example, the first half or the latter half of a period of 3 minutes). ).

Next, the CPU 110 calculates a standard deviation of the respiration frequency (hereinafter referred to as “respiration frequency standard deviation”) as an index value representing the variation in the respiration frequency during the evaluation period (A3). Similarly, the CPU 110 calculates a standard deviation of the tidal volume (hereinafter referred to as “tidal volume standard deviation”) as an index value representing the variation of the tidal volume during the evaluation period (A5). Moreover, CPU110 determines the increase / decrease tendency of the minute ventilation in an evaluation period (A7).

Thereafter, the CPU 110 measures the IE ratio in the evaluation period (A9). The IE ratio is the ratio between the number of exhalations and the number of inspirations of the measurement subject, or the ratio between the expiration time and the inspiration time. Then, after determining the respiratory function type (A11), the CPU 110 ends the respiratory function type classification process.

FIG. 19 is an explanatory diagram of the determination method of the respiratory function type in A11, and illustrates a table in which the determination condition is associated with the respiratory function type. There are four types of respiratory function types: a respiratory rate compensation type, a ventilation volume compensation type, a mixed type, and an IE ratio change type.

The determination condition for determining the breathing rate compensation type is “the tidal volume standard deviation is below the threshold θ _α1 and the respiratory rate standard deviation is above the threshold θ _β1 and the minute ventilation is continuously increased. Is defined. In other words, if the tidal volume is generally constant, but the respiratory rate increases and the minute ventilation also tends to increase, the respiratory rate compensation type that increases the minute ventilation by increasing the respiratory rate is judge.

The determination condition for determining the ventilation compensation type is “the tidal volume standard deviation is greater than the threshold θ _α1 , the respiratory rate standard deviation is less than the threshold θ _β1 , and the minute ventilation is continuously increased. Is defined. In other words, if the respiratory rate is generally constant but the tidal volume increases and the minute ventilation tends to increase, the ventilation compensation compensates for increasing the minute ventilation by increasing the tidal volume. Judge as type.

The determination condition for determining the mixed type is that “the standard deviation of tidal volume exceeds the threshold θ _α1 , the standard deviation of the respiratory rate exceeds the threshold θ _β1 , and the minute ventilation continuously increases”. It has been established. That is, when the number of breaths increases, the tidal volume increases, and the minute ventilation also tends to increase, it is determined that the mixed type is a mixed type of the respiratory rate compensation type and the ventilation rate compensation type.

The determination condition for determining the IE ratio change type is that “the difference between the IE ratio measured at rest and the IE ratio measured at load exceeds the threshold θ”. In other words, if there is a significant difference between the IE ratio measured at rest and the IE ratio measured at load (ie during the walking test), the type of IE ratio of breathing changes between rest and load It is determined that the IE ratio change type.

(Measurement and display of various walking quantities)
The 6-minute walking test apparatus 1 measures walking amounts including at least one of the walking distance, walking speed, and position of the measurement subject, and displays the measured values on the liquid crystal 132 with a touch panel. The various walking quantities can also be referred to as various quantities (moving quantities) indicating the moving state of the measurement subject accompanying the walking of the measurement subject during the walking test. Hereinafter, a method for measuring each walking amount will be described.

(1) Measurement of walking distance Conventionally, a method for measuring a walking distance using a triaxial acceleration sensor is known. Each acceleration in the three-axis direction is measured by the three-axis acceleration sensor, and the measured acceleration varies characteristically with one step of walking motion, so it is determined from the waveform that one step of walking motion has been performed. It is possible, and this makes it possible to count the number of steps. This step count measuring method is often used. In addition, a technique is known in which a step length per step is determined by statistical data or a prediction formula by inputting height or the like into a pedometer, and a walking distance is calculated based on the determined step length and the measured number of steps. . However, since the step length per step varies from person to person, the above method cannot accurately measure the walking distance. In addition, there is a method of calculating the walking speed by integrating the acceleration, and further calculating the walking distance by integrating the walking speed, but in this case the direction of gravity relative to the walking surface varies depending on the walking posture, An accurate walking distance cannot be calculated.

In this embodiment, the walking distance is accurately calculated using the output signal of not only the triaxial acceleration sensor but also the triaxial geomagnetic sensor. Calculate the geomagnetic dip at the measurement point from the latitude and longitude of the measurement point in advance, and calculate the walking plane at the measurement point from the direction of the geomagnetism detected by the triaxial geomagnetic sensor and the calculated dip at the measurement point. In this method, the walking speed is calculated based on the acceleration component of only the walking surface, and the walking distance is calculated by further integrating the walking speed. Details will be described below.

As shown in FIG. 13, the dip angle distribution is open to the public, and the dip angle of the measurement point can be calculated from the latitude and longitude of the measurement point at which the 6-minute walking test is executed. The dip angle at the measurement point is calculated in advance. For example, regarding the method of calculating the dip angle, as shown in FIG. 14, the geomagnetic sensor when the main body 100 is in a vertical posture (a posture in which the negative direction of the z-axis is the gravitational direction, hereinafter referred to as a standard posture). The three-axis sensor output is x ₀ , y ₀ , z ₀ , the geomagnetic direction is represented as (x ₀ , y ₀ , z ₀ ), and the posture tilted from the standard posture when walking (hereinafter referred to as walking) The geomagnetism direction measured by the “posture” is represented as (x ₁ , y ₁ , z ₁ ). If the dip angle in the standard posture is α ₀ , α ₀ is an angle formed with the xy plane, so the following equation is established.

If the direction of geomagnetism in the walking posture is (x ₁ , y ₁ , z ₁ ) and the depression angle is α ₁ , the following formula is established.

The inclination of the main body 100 in this case is represented by α ₀ -α ₁ and is given by the following equation.

Therefore, in the data of the three-axis acceleration sensor, the plane obtained by inclining the xy plane by α ₀ -α ₁ becomes the walking plane, and the acceleration on the walking plane is the acceleration by walking. Further, the speed can be calculated by integrating the acceleration due to walking, and the distance can be calculated with high accuracy by further integrating. Specifically, the CPU 110 can calculate the acceleration on the walking surface by calculating the coordinate conversion formula shown below.

The data of the three-dimensional geomagnetic sensor in the standard posture is (x ₀ , y ₀ , z ₀ ), the data of the three-dimensional geomagnetic sensor in the walking posture is (x ₁ , y ₁ , z ₁ ), and a1 to a3, b1 When .about.b3 and c1 to c3 are expressed as coefficients of an equation for coordinate conversion, the following equation is established.

This is expressed by a determinant as follows.

If the inverse matrix is obtained, the walking posture can be converted to the standard posture. Similarly, if coordinate transformation is performed by multiplying the three-dimensional acceleration data in the walking posture by the inverse matrix, the main body 100 can be set in the standard posture, and the acceleration on the xy plane can be calculated as the acceleration on the walking surface. 3D acceleration data in the standard position _{(X 0, Y 0, Z} 0), if the three-dimensional acceleration data of the walking posture and _{(X 1, Y 1, Z} 1), the following expression _{(X 0} , Y ₀ , Z ₀ ) is obtained.

If the acceleration on the walking surface is _aw , the acceleration on the xy plane is calculated by the following equation.

The walking speed can be calculated by integrating the calculated _aw, and the walking distance can be calculated by integrating again. The acceleration on the walking surface calculated in this way and the above-mentioned respiratory system item and circulatory system measurement item are displayed as time-series data corresponding to the elapsed time from the start of measurement as shown in FIG. . By making the scale of elapsed time on the horizontal axis common to each item, it is possible to easily grasp how each item value has changed according to the elapsed time.

(2) Walking speed / position measurement By using a satellite positioning system represented by GPS (otherwise, WAAS, GLONASS, GALILEO, Beidou, etc.), the walking speed and position of the person being measured can be measured. it can. In this case, for example, a 6-minute walking test apparatus 1 is provided with a GPS receiver (GPS unit), and pseudo-positioning using a pseudo-range or Doppler positioning using a Doppler frequency is performed to determine the position of the person being measured. Measure. Moreover, speed calculation using the Doppler frequency is performed to measure the walking speed of the person being measured.

Also, instead of the satellite positioning system, it is also possible to measure the walking speed and position of the subject by performing inertial navigation calculations. In this case, for example, the 6-minute walking test apparatus 1 is provided with an acceleration sensor and an angular velocity sensor (gyro sensor) as an inertial sensor, and an inertial navigation calculation using an acceleration signal and an angular velocity signal output from the acceleration sensor and the angular velocity sensor. To measure the walking speed and position of the person being measured.

In this case, an inertial measurement device (IMU (Inertial Measurement Unit)) including a triaxial acceleration sensor and a triaxial angular velocity sensor is provided in the walking test apparatus 1 for 6 minutes, and an acceleration signal and angular velocity output from the inertial measurement device. The CPU 110 may perform inertial navigation calculation using signals, or a 6-minute walking test of an inertial navigation device (INS (Inertial Navigation System)) that performs inertial navigation calculation autonomously and outputs position and velocity The apparatus 1 may be provided.

In addition, it is good also as measuring a to-be-measured person's position and walking speed using together position calculation / speed calculation using a satellite positioning system, and inertial navigation calculation. For example, an average process (simple average process, weighted average process) that averages the position / velocity measured using a satellite positioning system and the position / velocity measured by performing an inertial navigation calculation is performed. You may make it measure the position and walking speed.

In addition, it is assumed that the walking test is usually performed outdoors (outdoor environment), but the walking test may be performed indoors (indoor environment). In this case, in an indoor environment, it is often difficult for the GPS receiver to receive a GPS satellite signal, and there is a possibility that it is impossible to measure the walking speed and position using the GPS. Therefore, an indoor transmitter (indoor base station) is installed in the building or facility where the walking test is performed, and the position of the person being measured is determined by performing triangulation based on the signal transmitted from the indoor transmitter. You may measure. Moreover, it is good also as installing a pseudolite as an indoor transmitter. A pseudo satellite is a pseudo satellite that simulates a positioning satellite in a satellite positioning system. For example, information similar to information included in a navigation message transmitted by a satellite signal transmitted from a positioning satellite, It is configured to be able to transmit a pseudo satellite signal including information such as an installed position. The position of the person to be measured may be measured or specified based on the pseudo satellite signal received from the pseudo satellite.

In FIG. 15, the respiratory frequency (RR), inspiratory tidal volume equivalent (vTi), expiratory tidal volume equivalent (vTe), pulse rate (PR), and SpO ₂ time transition are all common. It is displayed on the time axis, and the time transition of each item can be easily compared during and before and after the test for 6 minutes. The exercise limiting factor can be estimated from a comparison of the pulse rate, which is a circulatory system measurement item, with the respiratory frequency, which is a respiratory system measurement item, equivalent to a tidal volume, and equivalent to a minute ventilation. As shown in FIGS. 8 to 10, the X axis of one graph is the time axis of the common scale, and the circulatory system measurement item and the respiratory system measurement item are displayed on the same graph (the scale of the Y axis is The graphs of the respective items may be displayed side by side with the time axis as a common scale as shown in FIG.

In the conventional 6-minute walking test apparatus, there was no means for recording the walking state of the patient under test, so when it stopped during the walking test, an observer had to record it separately as an event. . In the 6-minute walking test apparatus according to the present embodiment, the acceleration on the walking surface is recorded as the measurement data, so that the walking state during the walking test can be grasped in detail, and even if the person to be measured stops, Since the movement and stop state are reflected in the acceleration data, it is not necessary to keep a separate record of the walking state. The start and stop of walking are automatically recorded. In addition, since the walking speed and walking distance can be accurately calculated according to the elapsed time by the above-described method, it is possible to identify a decrease in walking speed and a stagnant walking distance after measurement. Therefore, an observer such as a medical staff can concentrate on observing the condition of the subject.

In addition, since it is possible to calculate the distance (step length) per step by counting the number of steps, for example, the ratio of the stride at the start of the test to the stride at the end of the test (step length at the end of the test / step at the start of the test) It is also possible to quantify the degree of fatigue based on the stride. In addition, since it is possible to measure changes in walking speed over time, the fatigue level is quantified by, for example, the ratio of the walking speed at the start of the test and the walking speed at the end of the test (walking speed at the end of the test / walking speed at the start of the test). It is also possible to

(Measurement before walking)
As described above, the 6-minute walking test apparatus 1 uses the flow sensor in the pre-rest state prior to the start of the walking test, and the forced vital capacity (FVC), 1 second amount (FEV1), 1 second rate (FEV1%) ,% FEV1 (% FEV1) as well as measuring, measuring the SpO ₂ and pulse rate with SpO ₂ probe. Further, it is confirmed whether or not the subject is awakened at rest using a nostril cannula. It is also possible to set a pre-rest period (for example, a period of 3 minutes) for measurement in the pre-rest state, and start the walking test after the pre-rest period.

In this case, if the subject is a healthy person or a non-measuring person who does not have a serious problem with the respiratory system or circulatory system, the circulatory system item or respiratory system can be used without waiting for a three-minute pre-rest period. The measured value of the item tends to be stable. Therefore, when the variation of some or all of these measured values is less than the preset value, the measurement in the pre-rest state is automatically terminated without waiting for the pre-rest period, and the walking test is performed. It is also possible to start.

(Measurement after walking)
When 6 minutes have elapsed from the start of walking, the buzzer 133 sounds and “6 minutes have elapsed” is displayed on the liquid crystal 132 with a touch panel. In connection with this, a to-be-measured person complete | finishes walking. Then, the nostril cannula 180 is removed from the main body 100, and instead, the flow sensor 150 is connected again to the main body 100, and the forced vital capacity (FVC), 1 second amount (FEV1), as before the start of walking. 1 second rate (FEV 1%),% 1 second amount (% FEV 1), etc. are measured. SpO ₂ and pulse rate are also measured. Furthermore, the blood pressure is also measured to confirm the systole and the diastolic phase by checking with the modified Borg scale. The value of each item measured after the end of walking is stored together with the value of each item before the start of walking, and both are displayed on the liquid crystal 132 with a touch panel so that they can be compared.

In addition, the 6-minute walking test apparatus 1 is a cardiovascular system item or respiratory system in a resting state before starting the walking test (pre-resting state) and a resting state after finishing the walking test (post-resting state). The measured value of the item is acquired, and the recovery status of each item in the post-rest state with respect to the pre-rest state is determined and displayed.

It is conceivable to measure how long it takes to recover to the measurement value in the pre-rest state in the post-rest state, but this has a problem that it takes a certain time. If it is a healthy person, the measured value of the respiratory system item and the circulatory system item tends to recover to the measured value in the pre-rest state in about 3 minutes after exercise. Therefore, a recovery coefficient indicating how much of the measured value of each item has recovered in the period of 3 minutes in the post-rest state is calculated, and this recovery coefficient is displayed as the recovery status.

Also, the recovery time is measured as the recovery time of the measured value of the circulatory system item such as SpO ₂ and the pulse rate and the measured value of the respiratory system item such as minute ventilation to the measured value in the pre-rest state. Is displayed as the recovery status.

[Other functions of 6-minute walking test device]
As described above, the main functions of the 6-minute walking test apparatus 1 have been described. However, the 6-minute walking test apparatus 1 according to the present embodiment has the functions described below.

As described above, a walking test may be performed while supplying oxygen to a subject using a nostril cannula. In this case, it is determined whether the oxygen flow rate (hereinafter referred to as “set oxygen flow rate”) set for the oxygen supply device (oxygen supply means) before the start of the walking test is appropriate or during the walking test. It is possible to determine whether or not oxygen is appropriately supplied to the measurement subject.

FIG. 20 is a flowchart showing the flow of the pre-walking test determination process executed by the CPU 110 in this case. Note that the processing shown in FIG. 20 may be executed in the same manner even after the walking test. First, the CPU 110 obtains an appropriate oxygen flow rate (B1). The appropriate oxygen flow rate is, for example, an oxygen flow rate that is recognized by the measurement subject or the operator as a set oxygen flow rate (whether it is actually set or not), and the oxygen flow rate that is considered appropriate is displayed on the operation unit (for example, a touch panel). It can be obtained by inputting from the attached liquid crystal 132). In addition, the measurement subject or the operator may input parameters (age, weight, sex, etc.) of the measurement subject, and an appropriate oxygen flow determined based on the input parameters may be set as the appropriate oxygen flow. good. Next, the CPU 110 estimates the pressure offset value based on the oxygen flow rate based on the appropriate oxygen flow rate, and stores it in the RAM 121 as the estimated offset value (B3). The pressure offset value based on the oxygen flow rate is substantially proportional to the oxygen flow rate. Therefore, correlation data (correlation equation or correlation table) that defines the correlation between the appropriate oxygen flow rate and the offset value is stored in the ROM 122 in advance, and the appropriate oxygen flow rate acquired in B1 is handled based on the correlation data. An offset value is obtained and used as an estimated offset value. For example, the estimated offset value may be stored in the RAM 121 as 100. Next, the CPU 110 performs a determination process for determining whether or not the supplied oxygen flow rate is within an appropriate range (B5).

FIG. 21 is a flowchart showing the flow of the determination process.
CPU110 acquires the to-be-measured person's respiration waveform in the state by which oxygen was supplied to the to-be-measured person from the oxygen supply device (C1). The respiratory waveform referred to here is time-series data of the respiratory pressure of the measurement subject. And CPU110 measures an offset value based on the acquired respiration waveform, and memorize | stores it in RAM121 as a measurement offset value (C3). The measurement offset value can be acquired, for example, by performing a filter process that cuts an AC component (AC component) from the respiratory waveform (respiration pressure time-series data) of the measurement subject. For example, the measurement offset value when the estimated offset value described above is set to 100 may be calculated and stored in the RAM 121.

Next, the CPU 110 determines whether or not the absolute value of the difference between the estimated offset value and the measured offset value stored in the RAM 121 exceeds a predetermined first threshold value (C5). The first threshold value used here is preferably in the range of 10 to 20 when the estimated offset value is 100, for example, and may be determined based on the error range of the oxygen flow rate supplied by the oxygen supplier, for example. For example, assuming that the error in the oxygen flow rate supplied from the oxygen supply device to the measurement subject is approximately ± 10% of the set value, the estimated offset value (here, 100) and the measurement offset value When the absolute value of the difference exceeds 10, the actual oxygen flow rate deviates from the oxygen flow rate considered appropriate. Therefore, in this case, the threshold value should be 10.

When it is determined that the absolute value of the difference between the estimated offset value and the measured offset value exceeds the first threshold value (C5; Yes), the supply oxygen flow rate is determined to be inappropriate, and inappropriate and continuous. Then, the improper time determined as the time determined (or the improper number of times determined consecutively as improper) is updated (C7). Then, the CPU 110 determines whether or not the inappropriate time (or the inappropriate count) exceeds a predetermined second threshold (C9). And when it determines with having exceeded the 2nd threshold value (C9; Yes), it alert | reports that an oxygen flow rate is improper (C11). For example, an alarm or a beep is sounded to notify that the oxygen flow rate is inappropriate. Further, a message “The set oxygen flow rate is not appropriate” may be displayed on the screen.

For example, there may be a case where the absolute value of the difference between the estimated offset value and the measured offset value exceeds the first threshold value due to a large change in the instantaneous value of the measured offset value due to a temporary change in the oxygen flow rate. The In such a case, immediately informing that the set flow rate is inappropriate with the instantaneous value may be a factor that hinders the smooth progress of the walking test. Therefore, in this example, when the inappropriate time (or inappropriate number of times) exceeds the second threshold value, the fact that the oxygen flow rate is inappropriate is notified. The second threshold value used here is, for example, the time until the oxygen flow rate is stabilized after setting the oxygen flow rate of the oxygen supply device (or the number of determinations corresponding to that time), and the oxygen flow rate temporarily fluctuated due to some factor. In this case, the time until the oxygen flow rate stabilizes (or the number of determinations corresponding to that time), or the time that does not have a significant effect on the subject or the walking test (or the time) The number of times of determination) is good.

On the other hand, if it is determined that the absolute value of the difference between the estimated offset value and the measured offset value does not exceed the first threshold (C5; No), the inappropriate time (or inappropriate number of times) is cleared (C13). . Therefore, if the absolute value of the difference between the estimated offset value and the measured offset value falls below the threshold before the inappropriate time (or the inappropriate number of times) exceeds the threshold, the error is reported before the flow inappropriate notification is performed. The appropriate time (or inappropriate number of times) is cleared. Then, the CPU 110 checks whether or not a predetermined determination time has elapsed (C15). If the determination time has elapsed (C15; Yes), the determination process is terminated. If the determination period has not elapsed (C15; No), the process returns to C1 and the determination process is continued. When the inappropriate time (or inappropriate number of times) is equal to or less than the second threshold value (C9; No), the process proceeds to C15 without notifying that the oxygen flow rate is inappropriate.

Referring back to FIG. 20, the CPU 110 confirms whether or not a notification that the oxygen flow rate is inappropriate is being performed (B7). If there is no notification that the oxygen flow rate is inappropriate (B7; No), the determination process before the walking test is terminated. In connection with this, a to-be-measured person will transfer to a walk test. On the other hand, if a notification that the oxygen flow rate is inappropriate (B7; Yes), the CPU 110 performs a resetting operation (for example, a liquid crystal 132 with a touch panel) for resetting the oxygen flow rate and redoing the appropriateness determination. It is determined whether or not the selection of the cancel button displayed on (B9) has been made (B9), and if it has been determined (B9; Yes), the notification that the oxygen flow rate is inappropriate is terminated (B13). Then, the determination process before the walking test is terminated. In connection with this, a to-be-measured person and an operator will reset oxygen flow volume with respect to an oxygen supply device. In addition, the appropriate oxygen flow rate and parameters are re-input as necessary. On the other hand, if it is determined that the resetting operation has not been performed (B9; No), the notification that the oxygen flow rate is inappropriate is continued (B11), and the process returns to B9.

In this example, the flow rate inappropriateness notification is continued until the resetting operation is performed, but the flow rate inappropriateness notification is terminated when a predetermined time elapses without performing the resetting operation. Anyway. In addition, when the flow rate improper notification is being executed, the determination process of FIG. 21 is allowed to be executed, and it is determined that the absolute value of the difference between the estimated offset value and the measured offset value does not exceed the first threshold value. (C5; No), the inadequate flow rate notification may be terminated.

FIG. 22 is a flowchart illustrating a flow of a determination process during a walk test that detects an abnormality in the flow rate of oxygen supplied from the oxygen supply device to the measurement subject during the walk test.
CPU110 performs the process similar to the determination process shown in FIG. 20 (D5). That is, based on the breathing waveform of the person being measured during the walking test, it is confirmed whether or not the supplied oxygen flow rate is inappropriate, and if it is inappropriate, the fact is notified. . In the determination process of FIG. 21 in the determination process during the walking test, it is confirmed whether or not the test time has elapsed in C15 (for example, whether or not 6 minutes have elapsed since the start of the test).

CPU110 confirms whether the notification to the effect that the oxygen flow rate is inappropriate is performed (D7). If there is no notification that the oxygen flow rate is inappropriate (D7; No), the determination process during the walking test is terminated. On the other hand, if the notification that the oxygen flow rate is inappropriate (D7; Yes), the CPU 110 selects a cancel operation for canceling the walking test (for example, selecting a cancel button displayed on the liquid crystal 132 with a touch panel). ) Is determined (D9). If it is determined (D9; Yes), the notification that the oxygen flow rate is inappropriate is terminated (D13), and the determination process during the walking test is terminated. To do. On the other hand, if it is determined that the cancel operation has not been performed (D9; No), the notification that the oxygen flow rate is inappropriate is continued (D11), and the process returns to D9.

In this example, the flow rate inappropriateness notification is continued until the stop operation is performed, but the flow rate inappropriateness notification is terminated when a predetermined time elapses without the stop operation being performed. Also good. Further, the determination process of FIG. 21 is made executable even during the period in which the flow rate improper notification is being executed (that is, the walking test can be continued), and the absolute value of the difference between the estimated offset value and the measured offset value is When it is determined that the threshold value is not exceeded (C5; No), the flow rate inappropriateness notification may be terminated and the walking test may be continued.

In the above example, whether or not the oxygen flow rate is inappropriate is checked based on whether or not the absolute value of the difference between the estimated offset value and the measured offset value exceeds the first threshold value. For example, the oxygen flow rate may be checked based on the ratio of the measured offset value to the estimated offset value. For example, if the ratio of the measured offset value to the estimated offset value is 80% or less, the flow rate inappropriateness notification may be performed.

Also, in the determination process during the walking test, it is checked whether the ratio of the measured offset value to the estimated offset value has decreased over time (for example, the ratio is calculated every predetermined time). In addition, when it is confirmed that it has decreased over time (for example, when it has decreased by a predetermined threshold or more from the ratio calculated at the first time), it is notified that the remaining amount of the oxygen supply device has decreased. Anyway. Further, it is possible to detect a change in the oxygen flow rate by a change with time of only the measurement offset value without using the estimated offset value, and detect an abnormality based on the change. You may make it estimate that the residual amount of an oxygen supply device is falling based on having fallen.

(Maximum ventilation measurement by spirometer function)
When the flow sensor 150 is connected to the main body 100 before the start of walking, it is possible to measure the forced vital capacity, the amount of 1 second, etc., but the flow can be accurately measured (the so-called spirometer function is provided). Therefore, the maximum ventilation (also referred to as MVV) can be measured together with these items. During walking, as described above, it is possible to measure the tidal volume equivalent or the minute ventilation equivalent using the nostril cannula 180. Therefore, by measuring the maximum ventilation before the start of walking, for example, during the walking test, the ventilation volume with respect to the maximum ventilation volume (equivalent to tidal volume or minute ventilation volume) If the condition that exceeds the ratio continues for a predetermined time or more, it is assumed that the person being measured is unreasonable without being aware of his / her limit, and for example, a warning is given by the buzzer 133 to stop walking. It is possible to

(Prediction of walking distance)
As described above, the gender, age, weight, and height of the person to be measured are input from the liquid crystal 132 with a touch panel when starting the test. In the walking test apparatus 1 of this embodiment, it is possible to calculate the predicted value of the walking distance of the measurement subject from the input age, weight, and height. For example, as shown in Non-Patent Document 2, the value obtained by {[454-0.87 × age (age) −0.66 × weight (kg)] × ± 82 m (2SD)} × height (m) Can be used as a normal range of the walking distance, and it is also possible to execute a determination as to whether or not the measured walking distance is within the normal range and display the determination result.

Further, the predicted value of the walking distance is not limited to the above formula, and may be calculated based on the following formula.
[Male] 6MWT (m) = (7.57 × height cm) − (5.02 × age) − (1.76 × kg body weight) −309 m
[Female] 6MWT (m) = (2.11 × height cm) − (2.29 × age) − (5.78 × kg body weight) +667 m

Note that the maximum oxygen intake (peak VO ₂ ) of the measurement subject can be calculated based on the following equation. Here, 1ft = 0.3048 m.
peak VO ₂ = 0.006 × walking distance (ft) +7.38

(BODE index display function)
As exemplified in Patent Document 1, a spirometer that determines the severity of COPD based on the amount of 1 second or the like is known, but as shown in Non-Patent Document 2, only the amount of 1 second or the like is known. In addition, techniques for evaluating the severity of COPD from other indices are also used. Non-Patent Document 2 discloses a method for determining the severity of COPD based on the following items.
1. B (Body Mass Index, BMI)
Calculated as weight (kg) / height (m) / height (m). For example, in the case of 160 cm and 75 kg, BMI = 75 ÷ 1.6 ÷ 1.6 = 29.
2. O (Obstruction)
An index indicating the degree of airway obstruction due to lung function, and a predicted value of 1 second rate is used.
3. D (Dyspnea)
This is an index indicating subjective feeling of dyspnea, and the value of dyspnea (0 to 4) is determined after hearing the subject using the MRC dyspnea scale.
4). E (excercise)
It is an index indicating the numbering ability, and the walking distance in the 6-minute walking test is used.

Among the above items, only the MRC dyspnea scale is a subjective index, but the other items are calculated or measured by the 6-minute walking test apparatus 1. Accordingly, the value of the MRC dyspnea feeling scale is determined by interviewing the measurement subject and input to the walking test apparatus 1 for 6 minutes, so that the range of each of the above items 1 to 4 is obtained as shown in FIG. Based on this, BODE index is determined and displayed on the walking test apparatus 1 for 6 minutes. Thereby, the severity of COPD is easily determined. In the example of FIG. 16, as the BODE index increases to 0, 1, 2, 3, the severity of COPD increases.

(Risk indication)
Moreover, in the 6-minute walking test apparatus 1 of this embodiment, it is also possible to display the hospitalization risk from the comparison with the statistical data based on the measured walking distance for 6 minutes. As a specific example, based on statistical data that the hospitalization risk increases when the walking distance is 357 m or less, it is possible to display that the hospitalization risk is high when the measured walking distance is 357 m or less. It is.

[Other Embodiments]
Finally, an example of another embodiment different from the above embodiment will be described. Embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention. In addition, about the same structure as said each embodiment, the same code | symbol is attached | subjected and description for the second time is abbreviate | omitted.

[Walking test system]
In the above embodiment, a walking test system that transmits measurement data during a walking test to an information communication device (communication device) such as a tablet terminal, a multi-function remote controller, or a personal computer may be configured.

FIG. 17 is a diagram illustrating an example of a system configuration of the walking test system 1000 in this case.
The walking test system 1000 includes a 6-minute walking test apparatus 1, a tablet terminal 3, and a printer 5.

The 6-minute walking test apparatus 1 includes a wireless communication unit 11 and is configured to transmit measurement data during the walking test to the tablet terminal 3 using wireless communication. The tablet terminal 3 is a tablet-type portable information communication device that includes a wireless communication unit 31 and is configured to receive measurement data transmitted from the 6-minute walking test apparatus 1. As a wireless communication method, a known wireless communication method such as Bluetooth (registered trademark) or WiFi can be applied.

The tablet terminal 3 includes a wireless communication unit 31 and a touch screen 33 in which a touch panel and a liquid crystal display are integrally formed, and measurement data received from the 6-minute walking test apparatus 1 by the wireless communication unit 31 is a touch screen. By being displayed on the screen 33, a manager such as a person in charge of the walking test, a doctor, or a nurse can check the measurement data at any time, or the measurement subject can check the measurement data after the walking test is completed. In addition, the tablet terminal 3 and the printer 5 are connected by communication, and the measurement data is output from the tablet terminal 3 to the printer 5 so that the measurement data can be printed.

From the 6-minute walking test apparatus 1, measurement of respiratory system items (respiration frequency, tidal volume equivalent, minute ventilation equivalent, SpO ₂ ) and circulatory system items (pulse rate, SpO ₂ ) are measured. The value is transmitted as measurement data. In this case, in the above wireless communication system, since the transfer time is not in time if the real-time waveform data of the measurement values of each item is transmitted, the 6-minute walking test apparatus 1 has a regular timing (for example, 1 second or 30 seconds, The measured value at the timing is transmitted to the tablet terminal 3 at a timing of once per minute) or intermittent timing.

In addition, you may make it transmit a measured value to the tablet terminal 3 at a specific timing instead of a periodic timing or an intermittent timing. Specifically, the measured value of at least one of a plurality of items included in the respiratory system item or the circulatory system item is in a dangerous state for the subject to continue the walking test. The measured value may be transmitted to the tablet terminal 3 at a timing when the dangerous condition indicating the condition is satisfied. For example, when SpO ₂ falls below a predetermined lower limit value, or when the number of breaths or the pulse rate exceeds a predetermined upper limit value, the measured value at that timing is transmitted to the tablet terminal 3 assuming that the dangerous condition is satisfied. You may do it.

Also, a shortness coefficient indicating the degree of shortness of breath of the measurement subject may be calculated, and this shortness coefficient may be transmitted to the tablet terminal 3 at the above transmission timing. The shortness of breath coefficient can be calculated based on the measured values of respiratory system items. In patients with COPD, the increase in the amount of arousal caused by exercise such as a walking test is limited to a low value and tends to reach a peak. Therefore, a shortness coefficient of a predetermined number of stages (for example, 10 stages) is determined, and the shortness coefficient is determined based on the increase rate corresponding to the measured single arousal amount or a value that reaches a peak. The determined shortness of breath can be displayed on the walking test apparatus 1 for 6 minutes, transmitted to the tablet terminal 3 to be displayed, printed on the printer 5, and the like.

Also, as a walking test, there is a case where a walking test is performed in which a predetermined walking section in which a cone or the like is arranged is reciprocated by a person to be measured. In this case, for example, an operation button for counting up is provided in the walking test apparatus 1 for 6 minutes, and the operation button is pressed every time the measured person turns at the cone placement position during the walking test. The number of times may be input to the walking test apparatus 1 for 6 minutes. Then, the number of turns may be transmitted to the tablet terminal 3 together with the measured values of the circulatory system item and the respiratory system item.

In addition, a plurality of types of event buttons (icons) indicating various events related to the walking test and the contents of the events are displayed on the touch screen 33 of the tablet terminal 3, and the event buttons displayed on the touch screen 33 are tapped. As a trigger, identification information for identifying the corresponding event may be stored in association with the measurement data of the measurement subject at that time. Here, the event related to the walking test is an event set based on the walking test method, the data measurement method, and the like, for example, “1. Stop walking”, “2. Meander walking”, “3. You can set multiple types of events, such as “Out”. In this case, the number assigned to each event can be stored as identification information in association with the measurement data. The type and content of the event can be freely set according to the walking test method, the data measurement method, the facilities of the facility where the walking test is performed, and the like.

In the above embodiment, an example in which the nostril cannula 180 is used for measuring the respiratory pressure during the walking test has been described, but the face mask 190 that covers the nostril and the mouth may be used instead of the nostril cannula 180. Similarly to the nostril cannula 180, the face mask 190 also has one terminal, and that terminal is connected to the luer connector 142 (that is, a port that outputs a negative voltage when exhalation is applied) to thereby measure the respiratory pressure of the subject. It is possible to capture changes. Here, since the nostril cannula 180 is inserted into the nostril as described above, there is a problem in that exhalation / inspiration cannot be completely captured when the measurement subject breathes through the mouth. On the other hand, when the face mask 190 is used, both the nostril and the mouth are covered. Therefore, it becomes possible to capture the exhaled air / inspired air and measure the ventilation amount more accurately.

When the face mask 190 is used, carbon dioxide retention in the face mask 190 becomes a problem. This corresponds to the left and right sides of the face mask 190 (corresponding to the cheek when the measurement subject wears it). It is advisable to provide a hole in the position) for releasing exhalation. Even when such a hole is provided, respiration pressure fluctuations can be accurately acquired. Which one to use is preferably used according to the condition and purpose of the person being measured.

In the above embodiment, the measurement items of the respiratory system are the number of breaths, equivalent to the tidal volume, equivalent to the minute ventilation, and SpO ₂ , and the measurement items of the circulatory system are the pulse rate and SpO ₂ Although explained, the measurement item of the respiratory system and the measurement item of the circulatory system are not limited to these. Further, in the example shown in FIGS. 8 to 10, the temporal change of SpO ₂ may be graphed together.

In the above embodiment, an example of calculating an inflection point based on a linear regression line has been described. However, the present invention is not limited to this. For example, a range in which the differential value of each item converges within a predetermined range is a flat region. And the starting point of the flat region may be determined as the inflection point. An inflection point may be determined based on a decrease in the amount of time change of each item (for example, an inflection point may be a point at which the increase in pulse rate per 10 seconds is 2 or less). The method is not limited.

In the above-described embodiment, the example in which the acceleration in the walking surface is calculated based on the output signal of the 6-axis sensor and the walking speed and the walking distance are calculated based on this is described. However, based on the output signal of the acceleration sensor The walking distance is calculated by counting the number of steps by detecting the walking motion (one step) and multiplying the number of steps by the step length calculated based on the input information such as height or the step length specified based on the statistical value from the input information. It may be calculated.

In the above-described embodiment, the example in which the walking test apparatus is a 6-minute walking test apparatus for a walking time of 6 minutes has been described, but the walking test time is not limited to 6 minutes. It goes without saying that the walking test apparatus of the present invention is intended for any walking time.

Claims (22)

1. A walking test apparatus comprising a measuring means for measuring respiratory system items and circulatory system items during walking of the subject,
   A walking test apparatus further comprising display means for displaying the change over time of the measurement value related to the respiratory system item and the change over time of the measurement value related to the circulatory system item in a comparable manner.
2. A walking test apparatus according to claim 1,
   A first time point at which a change over time in the measured value related to the respiratory system item falls within a first predetermined range is specified, and a second time point at which the change over time in the measured value related to the cardiovascular system item falls within a second predetermined range Further comprising a specifying means for specifying,
   The walking test apparatus characterized in that the display means displays the front-rear relationship between the first time point and the second time point so as to be grasped.
3. A walking test apparatus according to claim 2,
   A discriminating means for discriminating whether the movement limiting factor is the respiratory system or the circulatory system based on the context between the first time point and the second time point;
   The walking test apparatus characterized in that the display means displays the movement limiting factor discriminated by the discriminating means so as to be grasped.
4. A walking test apparatus according to claim 3, wherein
   The gait test apparatus characterized in that the discrimination means discriminates that the exercise limiting factor is a respiratory system based on the fact that the first time point is earlier than the second time point.
5. A walking test apparatus according to claim 3, wherein
   The gait test device characterized in that the discrimination means discriminates that the exercise limiting factor is a circulatory system based on the fact that the second time point is earlier than the first time point.
6. A walking test apparatus according to claim 3, wherein
   The discriminating unit discriminates that the exercise limiting factor is a respiratory system based on the fact that the first time point is earlier than the second time point, and based on the fact that the second time point is earlier than the first time point. A walking test apparatus characterized by discriminating that an exercise limiting factor is a circulatory system.
7. A walking test apparatus according to claim 6, wherein
   The walking test apparatus according to claim 1, wherein when the first time point and the second time point are not specified, the determining means determines that the exercise limiting factor is a muscle force system.
8. A walking test apparatus according to claim 3, wherein
   The measuring means measures at least one item selected from the respiratory rate and the ventilation volume as the respiratory system item, and measures the pulse rate as the circulatory system item.
9. A walking test apparatus according to claim 3, wherein
   The measuring means measures the respiratory rate and the ventilation volume as the respiratory system item,
   The said test | inspection means displays so that the relationship between the said frequency | count of breathing and the said ventilation quantity can be grasped | ascertained, The walk test apparatus characterized by the above-mentioned.
10. A walking test apparatus according to claim 3, wherein
    The measuring means measures a plurality of items selected from the respiratory rate, ventilation volume, and arterial oxygen saturation as the respiratory system item,
    The gait test device, wherein the display means displays the measured changes over time of each respiratory system item in a comparable manner.
11. A walking test apparatus according to claim 3, wherein
    Further comprising a classifying means for classifying the respiratory function tendency of the person to be measured based on the change over time of the measured value of the respiratory system item,
    The walking test apparatus characterized in that the display means displays the classified respiratory function tendency.
12. A walking test apparatus according to claim 11, wherein
    The measuring means measures the respiratory rate and the ventilation volume as the respiratory system item,
    The classifying means classifies the respiratory function tendency on the basis of a change with time of the respiratory frequency and the measured value of the ventilation amount.
13. A walking test apparatus according to claim 12, wherein
    The measuring means measures an IE ratio as the respiratory system item,
    The classifying means classifies the respiratory function tendency based on a change with time in the IE ratio.
14. A walking test apparatus according to claim 3, wherein
    The measurement means measures a respiratory system item and a circulatory system item of a measurement subject in a pre-rest state before starting the walking test and a post-rest state after finishing the walking test,
    A recovery status determining means for determining a recovery status of the measurement value of each item of the rear rest state with respect to the front rest state;
    The walking test apparatus characterized in that the display means displays the determined recovery status.
15. A walking test apparatus according to claim 3, wherein
    The measurement means further measures various walking amounts including at least one of a walking distance, a walking speed, and a position of the measurement subject during the walking test,
    The walking test apparatus, wherein the display means displays the measured walking quantities.
16. A walking test apparatus according to claim 15, wherein
    The measuring means includes an acceleration sensor and an azimuth sensor, and measures a walking distance of the measurement subject as the walking quantities based on detection results of the acceleration sensor and the azimuth sensor.
17. A walking test apparatus according to claim 3, wherein
    A pressure port to which a flow sensor can be connected;
    A nostril cannula or a face mask can be connected to the pressure port instead of the flow sensor,
    When the flow sensor is connected to the pressure port, the measuring means can measure one or more items selected from respiratory flow rate and ventilation volume, and when a nostril cannula or a face mask is connected to the pressure port A gait test apparatus characterized by being capable of measuring one or more items selected from respiratory pressure, respiratory rate, and ventilation volume.
18. A gait test device according to claim 17,
    The nostril cannula is provided with an oxygen path for supplying oxygen to the measurement subject from the oxygen supply means, in addition to the expiration path through which the measurement subject's exhalation passes.
19. A walking test apparatus according to claim 1,
    The apparatus further includes appropriate determination means for determining whether or not the set oxygen flow rate set in the oxygen supply means for supplying oxygen to the measured person is appropriate based on the respiratory data of the measured person. If the determination is negative, a walk test device that notifies that fact.
20. The gait test device according to claim 19, wherein
    2. The walking test apparatus according to claim 1, wherein the appropriateness determining means performs an appropriateness determination based on a measured offset value in the breathing data of the measurement subject, which is an offset value of pressure due to an oxygen flow rate.
21. A walking test apparatus according to claim 1,
    During the walking test, the apparatus further comprises an abnormality detection means for detecting an abnormality in oxygen supply from the oxygen supply means for supplying oxygen to the measurement subject to the measurement subject based on the respiratory data of the measurement subject. A walking test apparatus which notifies that when it is done.
22. A walking test apparatus according to claim 21, wherein
    The gait testing device, wherein the abnormality detecting means detects an abnormality based on a measurement offset value in a measurement subject's breathing data measured during a gait test, which is an offset value of pressure due to an oxygen flow rate.

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