JP6774061B2 - Mental and physical burden measurement system, mental and physical burden measurement method and program - Google Patents

Description

The present invention relates to a mental and physical burden measuring system, a mental and physical burden measuring method and a program for measuring the mental and physical burden of a subject in a supine or sitting position.

Common dental treatments are painful because the gums are anesthetized and denervated. Therefore, patients are often treated with anxiety, tension, and fear. In addition, as the patient receives pain many times due to the dental treatment, the discomfort becomes further increased by the stimuli that are not directly related to the pain, such as the sound and smell of sharpening the teeth generated in the treatment.

Currently, the dentist and the patient communicate the mental condition and the pain condition from the patient to the dentist by communicating with each other by speaking and raising their hands, and alleviate the negative condition. However, when using the raised hand, which is an active means of communication on the patient side, the patient may hesitate to communicate due to patience or shame. In this case, it is difficult for the dentist to grasp the patient's mental state (mental burden) and pain status (physical burden).

If the mental state and pain status of the patient undergoing dental treatment can be objectively measured or evaluated and the result can be communicated to the dentist during treatment, the dentist can proceed smoothly with the treatment, and the dentist can proceed with the result. Based on the above, it is possible to decide whether to continue or postpone the treatment according to the patient's condition.

In conventional research on pain and stress, subjective evaluation questionnaires are used as psychological evaluations, body sway and tremor are used as behavioral evaluations, and autonomic nervous activities such as sweating and saliva, brain activity, heart rate variability, skin temperature fluctuations, and skin potential reactions are used as physiological evaluations. Indicators have been used primarily. In particular, the sway of the center of gravity and the autonomic nerve activity index are excellent in real time. However, the electrical physiological indicators such as brain waves and heartbeats that require the wearing of the measuring device cause a feeling of restraint by the wearing itself, which may be a mental load or burden on the subject. In addition, since the measuring device is attached to the body of the subject, the measuring range for the patient is limited to a specific range. In order to objectively measure or evaluate the mental state and pain status of a patient undergoing dental treatment, a measurement method in which the patient does not care about the measuring device is preferable.

As a measurement method satisfying this condition, there are a method of measuring the skin temperature without contact and a method of measuring the sway of the center of gravity simply by the subject riding on the measuring device. The parts of the skin whose temperature changes due to mental load and strain are the peripheral parts such as the hands, feet, and nose. During dental treatment, the patient's limbs move, making it difficult to accurately measure temperature changes in the limbs. In addition, it is expected that the skin temperature of the nose etc. will change by irradiating the patient's face with lighting such as dental lighting equipment, and that the face will be hidden by the dentist's hands or treatment equipment due to treatment. Therefore, it is difficult to continuously measure the temperature even in the nose.

Therefore, the inventors paid attention to the measurement of body sway, which is an unconstrained measurement method capable of constant measurement. The center of gravity sway measurement is performed at the part in contact with the subject's body. Previous studies on body sway have been shown to be associated with visual and sound stimuli, physical and mental stress, and fatigue.

For example, Patent Document 1 discloses a mental / physical condition determination system for the purpose of predicting or determining the mental / physical condition of a subject without making the subject aware of it. This mental and physical condition determination system stores in a database a data processing means for calculating a mental and physical condition index such as a Lyapunov exponent from a time-series signal of the subject's load or the position of the center of gravity, a mental and physical condition index calculated by the data processing means, and a database. It has an evaluation means for predicting or judging the mental and physical condition of a subject by comparing with a known mental and physical condition index corresponding to the physical and mental condition.

International Publication No. 2004/082479 Pamphlet

By the way, what is disclosed in Patent Document 1 described above is a study on the sway of the center of gravity in a standing or sitting position. Patent Document 1 states that one or more center of gravity sway sensors can be mounted on the seat surface, backrest, etc. of a chair, and it is possible to unknowingly predict or judge the mental and physical condition of a medical patient in a hospital. Although there is a description, detailed studies have not been made on the state in which the patient is lying down, such as in the supine or lateral position in the medical field. Further, in the mental / physical condition determination system described in Patent Document 1, it is necessary to prepare a database that stores a known mental / physical condition index corresponding to the mental / physical condition. That is, it is necessary to measure the mental and physical condition index corresponding to the mental and physical condition in advance and create a database that stores the relationship between the mental and physical condition and the mental and physical condition index.

In view of the above situation, it is an object of the present invention to provide a mental and physical burden measuring system, a mental and physical burden measuring method and a program capable of measuring the physical and mental burden of a subject from the measurement result of the center of gravity sway of the subject with a simpler configuration. And.

The psychosomatic load measuring system according to one aspect of the present invention includes a center of gravity sway measuring device that is arranged so as to be able to measure the position of the center of gravity of a subject in a recumbent or sitting position and outputs time-series data of the position of the center of gravity of the subject. From the time-series data of the subject's center of gravity position, the center of gravity position processing unit that calculates the value of the evaluation index according to the subject's center of gravity sway, and the subject's mental and physical burden based on the time change of the calculated evaluation index value. It is provided with a burden measurement processing unit for measuring the above and an output processing unit for outputting the measurement result.

According to the present invention, it is possible to measure the physical and psychological burden of a subject from the measurement result of the body sway of the subject with a simpler configuration.

It is a top view and the side view which shows the example of the dental chair unit (chair with a movable backrest) used for the mental and physical burden measurement system in one Embodiment of this invention. It is a bottom view which shows the example of the center of gravity sway measuring apparatus. It is a block diagram which shows the structural example of the information processing apparatus of the mental and physical burden measurement system which concerns on one Embodiment of this invention. It is a figure explaining the example of the measurement program (GUI) in the mental and physical burden measurement system which concerns on one Embodiment of this invention. It is a figure explaining the method of calculating the locus length as an evaluation index from the scatter plot (trajectory) of the measured center of gravity which concerns on one Embodiment of this invention. It is a figure explaining the method of calculating the outer peripheral area as an evaluation index from the scatter diagram (trajectory) of the measured center of gravity which concerns on one Embodiment of this invention. It is a flowchart which shows the procedure example of the mental and physical burden measurement processing which concerns on one Embodiment of this invention. It is explanatory drawing which shows the output example of the measurement result by the mental and physical burden measurement processing which concerns on one Embodiment of this invention. It is a figure explaining the protocol of Experiment 1 using the mental and physical burden measurement system which concerns on one Embodiment of this invention. It is a graph which shows the change of the locus length of the center of gravity of a subject in Experiment 1. It is a graph which shows the change of the outer peripheral area of the locus of the center of gravity of the subject every minute in Experiment 1. It is a figure explaining the protocol of Experiment 2 using the mental and physical burden measurement system which concerns on one Embodiment of this invention. It is a figure explaining the evaluation section set in Experiment 2. It is a graph which shows the change of the locus length and the number of clicks of the back center of gravity of a subject in Experiment 2. It is a graph which shows the change of the outer peripheral area of the locus of the back center of gravity of the subject and the number of clicks in Experiment 2. It is a table which shows the increase rate of the number of clicks by a subject in Experiment 2. It is a graph which shows the change of the X coordinate and the number of clicks of the back center of gravity position of a subject in Experiment 2. It is a graph which shows the change of the weight and the number of clicks of the back and buttocks of a subject in Experiment 2. It is a table which shows the average value of the outer peripheral area of the locus of the back center of gravity before treatment, during treatment, and after treatment in each measurement of Experiment 2. It is a table which shows the standard deviation of the outer peripheral area of the locus of the back center of gravity before treatment, during treatment, and after treatment in each measurement of Experiment 2. It is a table showing the outer peripheral area of the locus of the back center of gravity during and after the treatment as a percentage when compared with the outer peripheral area of the locus of the back center of gravity before the treatment in each measurement of Experiment 2. It is a table which shows the determination success rate of the mental and physical burden in Experiment 2. It is the top view and the side view which shows the example of the unit structure (chair) which maintains a sitting state of a subject.

Hereinafter, an example of a mode for carrying out the present invention will be described with reference to the accompanying drawings. In the present specification and the accompanying drawings, components having substantially the same function or configuration are designated by the same reference numerals, and duplicate description will be omitted.

<One Embodiment>
In the present embodiment, assuming a situation in which the patient is being treated in a supine position while riding on a dental chair unit, the patient's center of gravity sway is measured using a center of gravity sway measuring device installed on the surface of the dental chair unit. By doing so, the patient's mental and physical burden (mental state, pain status, etc.) is objectively measured and evaluated.

FIG. 1 shows an example of a dental chair unit (chair with a movable backrest) used in the mental and physical burden measuring system according to the embodiment of the present invention. The upper part of FIG. 1 is a top view of the dental chair unit 1, and the lower part of FIG. 1 is a side view of the dental chair unit 1. In the present embodiment, the dental chair unit is used, but the present invention is not limited to this example as long as the subject can maintain the supine position. For example, it may be a general medical unit, a general-purpose chair with a movable backrest, or a bed.

The dental chair unit 1 shown in FIG. 1 includes a seat surface portion 2, a back surface portion 3, a center of gravity sway measuring device 4 arranged on the seat surface portion 2, and a center of gravity sway measuring device arranged on the back surface portion 3. 5 is provided. The dental chair unit 1 utilizes a medical unit (an example of a unit structure) generally used for the purpose of maintaining a sitting or supine position of a subject, and has a back portion 3 and a headrest portion. Various treatment instruments are built in the neck corresponding to the connection part of. The back surface portion 3 is configured to be rotatable and stoptable at an arbitrary angle so as to be an arbitrary angle with respect to the seat surface portion 2. In FIG. 1, the direction connecting the back surface portion 3 and the seat surface portion 2 (direction from the head to the foot) is defined as the X axis, and the direction perpendicular to the X axis (direction from the right shoulder to the left shoulder) is defined as the Y axis. The center of gravity sway measuring device 4 of the seat surface portion 2 and the center of gravity sway measuring device 5 of the back surface portion 3 are separated by a distance L (for example, 15 cm). The distance L is set to an arbitrary distance at which each of the center of gravity sway measuring devices 4 and 5 can satisfactorily acquire the load and the position of the center of gravity of the back or buttock of the subject. In the following description, the "back" mainly refers to the part from the back to the waist of the subject, and the "buttocks" mainly refers to the part from the buttocks to the thighs of the subject.

As shown in FIG. 2, the center of gravity sway measuring devices 4 and 5 have strain gauge type load sensors 11 to 14 built in at four corners of the lower surface portion. The center of gravity sway measuring devices 4 and 5 are based on the load applied to each of the four load sensors 11 to 14, the center of gravity position of the subject riding on the center of gravity sway measuring devices 4 and 5, and the load (weight) applied to the center of gravity position. ) Is measured. The center-of-gravity sway measuring devices 4 and 5 output measurement data of the position of the center of gravity of the subject in the supine position and the load applied to the position of the center of gravity (weight of the subject) at a predetermined sampling cycle.

In the present embodiment, the measurement positions of the center of gravity are two points, the back and the buttocks of the subject, which are considered to move during the treatment. The back of the subject is measured by the center of gravity sway measuring device 5, and the buttocks are measured by the center of gravity sway measuring device 4. Each of the center of gravity sway measuring devices 4 and 5 is provided with a short-range wireless communication I / F such as Bluetooth (registered trademark), and transmits the measurement result to the information processing device 20 (see FIG. 3) by wireless communication. The center of gravity sway measuring devices 4 and 5 may be configured by using a load sensor other than the strain gauge type, such as a piezoelectric type load sensor.

Generally, since the seat surface 2 and the back surface 3 of the dental chair unit 1 contain elastic cushions, if the center of gravity sway measuring devices 4 and 5 are directly installed on the seat surface 2 and the back surface 3, the load sensor Accurate measurement cannot be performed with 11 to 14. Therefore, the plates 6 and 7 are installed on the seat surface portion 2 and the back surface portion 3, respectively, and the center of gravity sway measuring devices 4 and 5 are arranged on the plates 6 and 7.

In addition, since there is a risk of pain if the subject is in the supine position directly on the center of gravity sway measuring devices 4 and 5, cushions 8 and 9 are installed on the center of gravity sway measuring devices 4 and 5, respectively. There is. This not only prevents the subjects from directly touching the body of the center of gravity sway measuring devices 4 and 5, but also prevents the subjects from showing the center of gravity sway measuring devices 4 and 5 so as not to cause tension in the subject. There are also advantages. Further, from the viewpoint of practicality, it is conceivable to incorporate the center of gravity sway measuring devices 4, 5, the plates 6, 7 and the cushions 8, 9 in the seat surface portion 2 and the back surface portion 3, respectively.

In the dental chair unit 1 configured in this way, the subject's buttocks (mainly the portion from the buttocks to the thighs) are in contact with the cushion 8 on the seat surface 2 side, and the subject 9 is in contact with the cushion 9 on the back surface 3. The back of the chair (mainly the part from the back to the waist) comes into contact. That is, the center of gravity sway measuring device 4 is arranged at a position where the weight of the buttocks of the subject is applied, and the center of gravity sway measuring device 5 is arranged at a position where the weight of the back of the subject is applied.

In Experiments 1 and 2, which will be described later, the Wii Balance Board (registered trademark), which is a controller of a game machine manufactured by Nintendo, was used as the center of gravity sway measuring devices 4 and 5. Previous studies have shown that the platform reaction force meter and the Wii Balance Board that meet the JIS (Japanese Industrial Standards) standard have a high correlation of 0.999 in mass and 0.989 in coordinate position, and the balance. The Wii board can be used as an inexpensive center of gravity sway measuring device.

[Configuration of mental and physical burden measurement system (information processing device)]
FIG. 3 is a block diagram showing a configuration example of an information processing device of the mental and physical burden measurement system according to the embodiment of the present invention. The mental and physical burden measuring system 30 shown in FIG. 3 is from a dental chair unit 1 in which the center of gravity sway measuring devices 4 and 5 are arranged and an information processing device 20 that processes measurement data sent from the center of gravity sway measuring devices 4 and 5. It is composed.

The information processing device 20 includes a control device 21, a memory 22, a non-volatile recording device 23, a display device 24, an input device 25, a short-range wireless communication I / F26, and a network I / F27. Each part of the information processing apparatus 20 is communicably connected to each other via a bus line (not shown). For the information processing device 20, for example, a personal computer can be used.

The control device 21 is configured to control the operation of the entire mental and physical burden measuring system 30 or each part of the mental and physical burden measuring system 30. For example, a central processing unit (CPU) is used as the control device 21. Details of the configuration and function of the control device 21 will be described later.

The memory 22 is a ROM (Read Only Memory) or a RAM (Random Access Memory). The memory 22 is an example of a recording medium, and the memory 22 stores programs, data, and the like necessary for the control device 21 to operate. The memory 22 may be configured to temporarily store variables, parameters, and the like generated during the arithmetic processing by the control device 21. The control device 21 reads the program code of the software that realizes each function according to the present embodiment from the memory 22 and executes it, and controls each part and performs various calculations. In addition, instead of the control device 21, another arithmetic processing unit such as an MPU (Micro Processing Unit) may be used.

The non-volatile recording device 23 is also an example of a recording medium, and the non-volatile recording device 23 stores a program for the control device 21 to control each part, a program such as an OS (Operating System), data, and the like. .. As the non-volatile recording device 23, for example, HDD (Hard Disk Drive), SSD (Solid State Drive), optical disk, optical magnetic disk, CD-ROM, CD-R, CD-RW, magnetic tape, memory card and the like are used. Be done. The program may be provided via a wired or wireless transmission medium such as a local area network (LAN), the Internet, or digital satellite broadcasting.

The display device 24 is, for example, a liquid crystal display monitor (an example of an output unit), and displays the result of processing performed by the GUI screen or the control device 21. An indicator light or a speaker may be provided as an output unit. For example, a pointing device such as a mouse or a touch panel, a keyboard, or the like is used as the input device 25, and the user can operate the input device 25 to input an instruction. The input device 25 generates an input signal according to the user's operation and supplies it to the control device 21.

The short-range wireless communication I / F 26 is an interface unit that performs wireless communication according to a short-range wireless communication standard such as Bluetooth. The short-range wireless communication I / F 26 receives measurement data from the short-range wireless communication I / F built in the center of gravity sway measuring devices 4 and 5 of the dental chair unit 1 and supplies the measurement data to the control device 21. The communication between the center of gravity sway measuring devices 4 and 5 and the information processing device 20 may be wired communication such as a dedicated line.

For the network I / F27, for example, a NIC (Network Interface Card), a modem, or the like is used, and various data are transmitted and received to and from an external device via a network such as a LAN to which terminals are connected or a dedicated line. Is configured to be possible.

(Configuration and function of control device)
The control device 21 includes a center of gravity position processing unit 211, a load measurement processing unit 212, an operation count measurement unit 213, and an output processing unit 214. Each part of the control device 21 is realized by the control device 21 (CPU) executing a program stored in the memory 22.

The center of gravity position processing unit 211 performs processing for calculating the value of the evaluation index according to the center of gravity sway of the subject from the time series data of the center of gravity position of the subject output by the center of gravity sway measuring devices 4 and 5. For example, the center of gravity position processing unit 211 calculates the outer peripheral area of the trajectory of the center of gravity for each predetermined time length from the time series data of the center of gravity position of the subject as an evaluation index according to the sway of the center of gravity of the subject. Alternatively, the center of gravity position processing unit 211 calculates the length of the trajectory of the center of gravity for each predetermined time length from the time series data of the center of gravity position of the subject as an evaluation index according to the sway of the center of gravity of the subject. The evaluation index according to the sway of the center of gravity of the subject is calculated in the evaluation interval of a predetermined time length for each set time as described later.

The burden measurement processing unit 212 performs a process of measuring the physical and mental burden of the subject based on the time change of the value of the evaluation index calculated by the center of gravity position processing unit 211. For example, the burden measurement processing unit 212 compares the value of the evaluation index according to the subject's center of gravity sway calculated by the center of gravity position processing unit 211 with a predetermined threshold value, and determines the mental and physical burden of the subject based on the comparison result ( evaluate. Further, the burden measurement processing unit 212 is configured to be able to determine the mental and physical burden of the subject by further considering the displacement (movement direction) of the center of gravity of the subject.

The operation count measuring unit 213 performs a process of measuring the number of times the subject operates the input device 25 when a physical stimulus is given to the subject. For example, a mouse is given to a patient as an input device 25, and the number of times a mouse button is clicked when pain is felt is measured. The number of operations measuring unit 213 is not an essential configuration of the mental and physical burden measuring system 30 according to the embodiment of the present invention. In Experiments 1 and 2, which will be described later, when objectively evaluating the physical and psychological burden of a subject based on the sway of the center of gravity, information on the number of clicks is used as an index of subjective evaluation to support the objective evaluation.

The output processing unit 214 performs a process of outputting the measurement result of the mental and physical burden of the burden measurement processing unit 212 to the input device 25, the network I / F27, the non-volatile recording device 23, and the like.

Here, a measurement program developed by the inventors to measure the position and weight of the center of gravity of a subject using the center of gravity sway measuring devices 4 and 5 will be described. FIG. 4 is an explanatory diagram showing an example of a measurement program (GUI) in the mental and physical burden measurement system 30, and is an example of a display screen 50 used in the measurement program. The display screen 50 has an input field for the user to measure and input the distance (distance from the center of each device to the center) of the two center of gravity sway measuring devices 4 and 5.

The "connection start button" is a button for instructing the start of connection between the center of gravity sway measuring devices 4 and 5 and the information processing device 20 by short-range wireless communication. In the example of FIG. 4, the connection start button is pressed and the connection establishment process such as Bluetooth is being performed. The number of the center of gravity sway measuring devices connected to the information processing device 20 is displayed according to the connection status between the center of gravity sway measuring devices 4 and 5 and the information processing device 20.

The "trial measurement button" is a button for instructing the start of the center of gravity sway measurement as a trial in order to check whether the center of gravity sway measuring devices 4 and 5 operate normally. When the center of gravity sway measuring devices 4 and 5 are performing measurement normally, the position and weight of the subject's center of gravity are displayed in the display areas of the X-axis, Y-axis, and weight items of the center of gravity sway measuring devices 4 and 5. The measured value of (load by each part) is displayed.
The "measurement start button" is a button for instructing the start of the center of gravity sway measurement of the subject by the center of gravity sway measuring devices 4 and 5. The measurement data of the subject is temporarily stored in the memory 22.

The "correction button" is a button for instructing the correction of the coordinates of the position of the center of gravity.
The "recording start button" is a button for instructing the start of the process of recording the measurement data of the subject's center of gravity sway in the non-volatile recording device 23 or an external memory such as a USB memory.
The "subject name", "site", and "situation" are input fields for setting a file name when the measurement data is stored in the non-volatile recording device 23 or the like.
The "selection button" is a button for selecting the output destination folder for measurement data.
The "connection end button" is a button for instructing the end of the center of gravity sway measurement of the subject by the center of gravity sway measuring devices 4 and 5.

The "calibration (weight) button" is a button for calibrating the measurement data of the weight of the subject by the center of gravity sway measuring devices 4 and 5.
The "calibration (coordinates) button" is a button for calibrating the measurement data of the center of gravity position (coordinates) of the subject by the center of gravity sway measuring devices 4 and 5.

The center of gravity sway measuring devices 4 and 5 using the Wii Balance Board can be connected to the information processing device 20 by using WiimoteLib, which is open source. Microsoft Visual C # was used for the program. In the measurements of Experiments 1 and 2, which will be described later, the sampling frequency was set to 100 Hz, but the accuracy of the timer function originally provided in Microsoft Visual C # is 15 msec, and it is difficult to measure accurately at 100 Hz. Therefore, measurement was performed using a high-precision timer with an accuracy of 1 msec using the Windows API called Multimedia Timer. Windows is a registered trademark. As a result, the center of gravity position coordinates and the weight can be measured in milliseconds at the same time from the two center of gravity sway measuring devices 4 and 5.

Here, the analysis of the measurement data is performed using the measurement program and the analysis program. The measurement data measured by using the measurement program is saved in a CSV (Comma-Separated Values) file. Then, this CSV file is read into the control device 21, and the analysis is performed by the analysis program. Microsoft Visual C # is also used for the analysis program, and the locus length of the center of gravity and the outer peripheral area of the locus of the center of gravity are calculated as evaluation indexes described below. The analysis program corresponds to the center of gravity position processing unit 211 of the control device 21.

[Evaluation index]
FIG. 5 is a diagram illustrating a method of calculating a locus length as an evaluation index from a scatter plot (trajectory) of the center of gravity measured by the center of gravity sway measuring devices 4 and 5. Further, FIG. 6 is a diagram illustrating a method of calculating the outer peripheral area as an evaluation index from the scatter plot (trajectory) of the center of gravity measured by the center of gravity sway measuring devices 4 and 5. The calculation formulas that serve as evaluation indexes are shown below.

(Trajectory length)
The locus length is the sum of the distances between continuous center of gravity positions for a predetermined time (for example, 1 second). Coordinate points A ₁ (x ₁ , y ₁ ), A ₂ (x ₂ , y ₂ ), ..., _An (x _n , y) as time series data of the center of gravity position measured by the center of gravity sway measuring devices 4 and 5. _It is assumed that _n ) is obtained. When the time of the evaluation period is t, the locus length d per second can be expressed by the following equation (1).

(Outer circumference area)
The outer peripheral area used for evaluating the sway of the center of gravity is generally expressed by an approximate calculation. In the calculation method used this time, first, the central position of the center of gravity sway during the period to be evaluated is determined. With this as the center, for example, 360 degrees is divided into 120 by 3 degrees, and the area surrounded by the line segment (outer circumference) connecting the longest points at the longest distance from the center position of each divided region is defined as the outer peripheral area. In this example, 360 degrees is divided into 120 by 3 degrees, but the number of divisions is arbitrary. The detailed calculation method is shown below.

Similar to the case of the locus length of the center of gravity, as the time series data of the position of the center of gravity, the coordinate points A ₁ (x ₁ , y ₁ ), A ₂ (x ₂ , y ₂ ), ..., An ( It is assumed that x _n , y _n ) is obtained. The coordinates of each coordinate point are corrected with the point at the center of the plurality of divided regions Sr1, Sr2 ... As a temporary origin O. That is, the average value of the X coordinate and the Y coordinate of the position of the center of gravity in the plurality of divided regions is obtained, and this is set as the temporary origin O. Then, the correction is performed by subtracting the average value of the XY coordinates, which is the temporary origin, from the values of the respective coordinates of the position of the center of gravity of the time series data. For example, if the corrected coordinates are tB ₁ (tx ₁ , ty ₁ ), tB ₂ (tx ₂ , ty ₂ ), ..., TB ₃ (tx _m , ty _m ), the position of the center of gravity after correction of the time series data. The X coordinate of is given by the following equation (2).

Next, the angle and distance from the temporary origin O are obtained for the coordinates of the corrected center of gravity position. If the angle theta _m, distance to _{d m,} theta _m and _{d m} is the following formula (3) is expressed by (4). θ _m is a frequency and ranges from −180 degrees to 180 degrees.

Next, it is determined in which of the divided regions Sr1, Sr2 ... The corrected center of gravity position coordinates are divided into 360 degrees by 3 degrees, and the longest point in the divided regions is determined. .. The coordinates of the longest point determined there are G ₁ (mx ₁ , my ₁ ), G ₂ (mx ₂ , my ₂ ), ..., G ₁₂₀ (mx ₁₂₀ , my ₁₂₀ ). The area (outer circumference area s) of the region surrounded by the outer circumference 60 connecting the longest points G _1, G _2, ..., G120 adjacent to each other can be expressed by the following equation (5).

[Procedure for measuring physical and mental burden]
Next, the procedure of the mental and physical burden measurement processing by the information processing device 20 of the mental and physical burden measurement system 30 will be described. FIG. 7 is a flowchart showing an example of a procedure for measuring the physical and mental burden. Each procedure of the mental and physical burden measurement processing shown in FIG. 7 is mainly performed by the control device 21 (CPU) executing a program stored in the memory 22.

First, the center of gravity sway measuring device 4 and / or 5 measures the position of the center of gravity of the subject lying on the dental chair unit 1 at a predetermined sampling cycle, and measures the position via the short-range wireless communication I / F26. Data (time series data) is transmitted to the control device 21 of the information processing device 20 (S1).

Next, the center of gravity position processing unit 211 of the control device 21 performs measurement data acquisition processing for acquiring time-series data of the center of gravity position of the subject output from the center of gravity sway measuring device 4 and / or 5 (S2). Then, the center of gravity position processing unit 211 performs a process of calculating the value of the evaluation index from the time series data of the center of gravity position (S3). The evaluation index calculated here is the outer peripheral area of the locus of the center of gravity and / or the locus length of the center of gravity per second.

Next, the load measurement processing unit 212 performs a process of detecting a time change of the value of the evaluation index calculated by the center of gravity position processing unit 211 (S4). Then, the burden measurement processing unit 212 measures the physical and psychological burden of the subject based on the time change of the value of the evaluation index (S5).

Finally, the output processing unit 214 performs a process of outputting the measurement result to the display device 24 and / or a speaker (not shown) (S6). Further, the output processing unit 214 may perform a process of recording the data indicating the measurement result in the non-volatile recording device 23. After the process of step S6 is completed, the output processing unit 214 ends the series of mental and physical burden measurement processes shown in FIG. 7.

FIG. 8 shows an output example of the measurement result by the mental and physical burden measurement processing. The indicator 70 is an example of a display element that informs the state and status of the physical and mental burden of the subject. The indicator 70 points to the vicinity of the scale indicating "no physical or mental burden" when there is no physical or mental burden on the subject (for example, in a resting state). As the physical and psychological burden on the subject increases (for example, during treatment), the indicated value of the indicator 70 increases. Then, when the physical and mental burden of the subject exceeds the threshold value, the indicated value of the indicator 70 exceeds the scale indicating "calling". When the dentist confirms that the indicated value of the indicator 70 exceeds the scale of "calling", the dentist calls out to the patient. The setting of the threshold value such as "calling" will be described later.

Although the display example of the indicator is shown in FIG. 8, a warning lamp may be displayed on the display screen, or the indicator may be notified by voice or music. Further, the time series data (waveform) of the position of the center of gravity as shown in FIGS. 14, 15, 17, and 18 may be displayed.

The experiment for measuring the mental and physical burden was carried out by two kinds of methods using the mental and physical burden measuring system 30 shown in FIG. The experiment was carried out in a state where the inclination of the back surface 3 of the dental chair unit 1 was horizontal.

[Contents of Experiment 1]
First, Experiment 1 will be described. In Experiment 1, the subject was asked to ride on the dental chair unit 1 in a supine position, and the subject was measured for 5 minutes by two methods. FIG. 9 shows the protocol of Experiment 1 using the mental and physical burden measurement system 30.

Experiment 1- (1): All subjects are rested for 5 minutes and the sway of the center of gravity is measured.
Experiment 1- (2): Measured with the 1st, 3rd, and 5th minutes in a resting state (Rest), and the 2nd and 4th minutes were set as "Task" to make the sound of the mouth washer. The subject's center of gravity sway is measured in the state. That is, "Rest" and "Task" are alternately repeated every minute for measurement. It should be noted that this stimulus is a sound stimulus that only produces the sound of the mouth washer, and is not a stimulus that causes pain in the body.

The subjects are three subjects A to C who are healthy adults. The experiment was conducted at an actual dental treatment site with the cooperation of a dentist. A scatter plot was created from the coordinates of the center of gravity of each subject obtained from the center of gravity sway measuring devices 4 and 5, and the states of the physical and mental burdens of the subjects in "Rest" and "Task" were compared. That is, after the experiment, the X and Y coordinates of the center of gravity at each sampling time were recorded, and each evaluation index was calculated. That is, the outer peripheral area and the locus length of the center of gravity per second were calculated every minute, and the evaluation indexes were compared in Experiment 1- (1) and Experiment 1- (2).

Conventionally, the total locus length, the outer peripheral area, and the unit area locus length have been mainly used as a method for comparing the data of the sway of the center of gravity. In this embodiment, the locus length of the center of gravity per second and the outer peripheral area are used as evaluation indexes. The trajectory length per second is a numerical value indicating how much the position of the center of gravity moves in one second, and the longer the trajectory length, the more unstable the center of gravity. Specifically, it is the average value of the locus length per second within the measurement time (for example, 1 minute). Here, the reason why the trajectory length per second is used instead of the total trajectory length is that it is difficult to compare the total trajectory length because the treatment time is not fixed. Further, the outer peripheral area indicates the range in which the position of the center of gravity moves during the measurement time (for example, 1 minute), and the larger the outer peripheral area, the more unstable the center of gravity.

[Result of Experiment 1]
First, the result of Experiment 1 will be described. FIG. 10 is a graph showing changes in the sway of the center of gravity of one subject A in Experiment 1, in which the vertical axis represents the locus length [cm] of the center of gravity and the horizontal axis represents time (min). In addition, FIG. 11 is a graph showing the change in the outer peripheral area of the locus of the center of gravity of subject A in Experiment 1 every minute, the vertical axis is the outer peripheral area of the locus of the center of gravity (cm ² ), and the horizontal axis is time (min). ) Is shown.

Looking at the second minute of the graphs shown in FIGS. 10 and 11, that is, between 1 minute and 2 minutes, the trajectory length and the outer peripheral area per second were both Experiment 1- (1) and Experiment 1- (2). There is a difference between them. The subject's swaying center of gravity suggested the possibility of measuring the subject's mental state, or mental burden, during dental treatment. Comparing the 4th minute of the graph shown in FIG. 10, there was almost no difference in the locus length per second between Experiment 1- (1) and Experiment 1- (2) between the back and buttocks. Further, in the graph shown in FIG. 11, a difference was observed between Experiment 1- (1) and Experiment 1- (2) regarding the outer peripheral area, but the difference was not as large as in the second minute.

It was also confirmed that the center of gravity of the back was moving more than the center of gravity of the buttocks. Therefore, it was shown that there is a possibility that the mental burden of the subject can be measured from the measurement data of only the center of gravity of the back. Furthermore, it was found that the outer peripheral area shown in FIG. 11 was significantly different between Experiment 1- (1) and Experiment 1- (2) than the locus length per second shown in FIG.

Although the graph is not shown, the measurements of Experiments 1- (1) and 1- (2) were performed for the other two subjects in the same manner. For one of the two subjects, subject B, experimental results showing the same tendency as the experimental results shown in FIGS. 10 and 11 were obtained. Regarding the other subject C, there was not much difference in the experimental results between Experiment 1- (1) and Experiment 1- (2). It is possible that this was a stimulus that did not burden the subject C because the stimulus presentation was only a sound stimulus.

In this way, it was confirmed that the back of each subject A to C was moving more than the buttocks. Therefore, it was shown that there is a possibility that the mental burden of the subject can be evaluated from the measurement data of only the back.

In addition, the difference in the measurement results between Experiment 1- (1) and Experiment 1- (2) was larger in the outer peripheral area than in the locus length per second for each of the subjects A to C. Therefore, it was suggested that the mental burden could be evaluated only by the outer peripheral area without comparing the locus length per second.

[Contents of Experiment 2]
Next, Experiment 2 will be described. In Experiment 2, as in Experiment 1, the subject was asked to ride on the dental chair unit 1 in a supine position, and measurement was performed under actual treatment. Two subjects (subjects D and E) were used in the experiment in which the 1st and 7th minutes were in a resting state, and the 2nd to 6th minutes were treated with tartar removal.

FIG. 12 shows the protocol of Experiment 2 using the mental and physical burden measurement system 30. In Experiment 2, the treatment time was set to 5 minutes as "Task", and a rest time of 1 minute was provided as "Rest" before and after the "Task", and the treatment was performed for a total of 7 minutes.

Further, in Experiment 2, in order to see at what time the subject was stimulated, that is, when the subject felt a physical and mental burden, the mouse was held in the right hand of the subjects D and E, and the mouse button was used when the subject felt pain. I asked them to click. The more painful the subject, the more clicks the button and the more clicks per unit time. As the evaluation index, the locus length and the outer peripheral area per second were used as in Experiment 1. In Experiment 2, for example, an evaluation interval of 5 seconds was set for the time series data, and the value of the evaluation index in each evaluation interval of the time series data was calculated at predetermined time (for example, 1 second). For pain, the number of times the mouse button was clicked within the same evaluation section was calculated and treated as an evaluation index.

FIG. 13 shows the evaluation section set in Experiment 2. In this example, each evaluation section overlaps in time. That is, when calculating the value of the evaluation index in the evaluation section set in 5 seconds, the calculation of the next evaluation section is started within 5 seconds after the calculation of the previous evaluation section is started. However, it is not limited to the case where each evaluation section overlaps in time.

[Result of Experiment 2]
Next, the result of Experiment 2 will be described. Similar to the results of Experiment 1, subjects D and E had larger changes (deviations) in the locus length of the center of gravity and the outer peripheral area of the locus of the center of gravity in the back than in the buttocks. Therefore, it was shown that even under actual treatment, it is possible to evaluate the physical and psychological burden by measuring only the center of gravity of the back. However, this does not exclude the evaluation of the mental and physical burden by measuring only the center of gravity of the buttocks, and the physical and psychological burden may be evaluated by measuring the centers of gravity of the back and buttocks. Hereinafter, FIGS. 14 to 15 show the measurement results of subject D as an example of the sway of the center of gravity of the back in Experiment 2.

FIG. 14 is a graph showing changes in the locus length and the number of clicks of the back center of gravity of subject D in Experiment 2. The vertical axis on the left side represents the locus length (cm) of the center of gravity of the back, the vertical axis on the right side represents the number of clicks (times), and the horizontal axis represents time (sec). FIG. 15 is a graph showing changes in the outer peripheral area of the locus of the back center of gravity of subject D and the number of clicks in Experiment 2. The vertical axis on the left side represents the outer peripheral area (cm ² ) of the locus of the center of gravity of the back, the vertical axis on the right side represents the number of clicks (times), and the horizontal axis represents the time (sec). In FIGS. 14 and 15, the alternate long and short dash lines at 60 sec and 360 sec indicate the start time and end time of the task (treatment).

As shown in FIGS. 14 and 15, it can be seen that the change (deviation) in the outer peripheral area (FIG. 15) is larger than the locus length of the center of gravity (FIG. 14), as in the result of Experiment 1. As shown in FIG. 15, subject D has a larger outer peripheral area at the time of treatment than at rest. The change in the outer peripheral area and the transition in the number of clicks are almost the same (corresponding), and it was shown that the pain (physical burden) of the subject can be measured by using the outer peripheral area. For example, in FIG. 15, around 270 seconds, which is the peak of the number of clicks, the outer peripheral area does not change much, but a large change can be seen in the outer peripheral area after the peak of the number of clicks ends. This is because the change in the center of gravity of the back is reduced by applying force to subject D against strong persistent pain, and then subject D is released from temporary pain as after the end of treatment. It is probable that the change in the center of gravity became large.

In addition, the outer peripheral area of subject D has increased significantly after the end of treatment (after 360 sec) (see time T5 in FIG. 15), and the center of gravity of the back can move even when subject D is released from the physical and mental burden. The sex was shown.

On the other hand, although the illustration is omitted, the subject E had a small difference in the outer peripheral area between resting and the treatment, and the number of clicks was 2 times in 5 seconds at the maximum, and he felt almost no pain. Subject E said that his impressions after the experiment did not hurt so much. From this, it was shown that the smaller the pain felt by the subject, the smaller the change in the outer peripheral area, and the greater the pain felt, the larger the change.

Except for subject E, who felt almost no pain in this experiment, two additional experiments were performed on subject D. Experiment 1 has no physical burden, but Experiment 2 is an experiment with a physical burden. Although not shown, in the additional experiment, as in the first experiment, the outer peripheral area changed significantly during the treatment as compared with before and after the treatment in both the second and third experiments. Moreover, even when the outer peripheral area and the number of clicks were compared, the change in the outer peripheral area and the transition of the number of clicks were almost the same (corresponding).

Next, in order to compare the case of only mental burden and the case of being given mental burden and physical burden (that is, mental and physical burden), the case where the number of clicks of pain is "0" and the case where the number of pain clicks is "1" or more. FIG. 16 shows a result of comparing the average value of the outer peripheral area of the locus of the center of gravity of each back with the outer peripheral area at rest. FIG. 16 is a table showing the rate of increase in the number of clicks by subject D in Experiment 2. "D1st time" to "D3rd time" means the 1st to 3rd time of the subject D, and "E" means the subject E.

In both subjects D and E, the average value of the outer peripheral area changed even when the number of clicks was "0", that is, when no pain was felt and only the mental burden was applied. Furthermore, when the number of clicks was "1" or more, that is, the average value of the outer peripheral area during treatment was increased by 42.4% as compared with the average value of the outer peripheral area before treatment. In other words, it was shown that the outer peripheral area increased significantly with pain. Therefore, it was found that both the painless mental burden and the painful mental and physical burden can be measured by using the outer peripheral area of the locus of the center of gravity. However, this does not exclude the evaluation of mental and physical burden by measuring only the trajectory length.

On the other hand, in FIG. 15, for example, around 215 seconds (time T1), 260 seconds (time T3), 315 seconds (time T4) seconds, and after the end of treatment (time T5), the number of clicks indicating pain decreased. Nevertheless, it was found that the outer peripheral area increased. Therefore, in order to see the movement of the subject D in more detail, the displacement of the center of gravity of the subject D, particularly the vertical direction of the body (head direction and foot direction) was focused on, and the outer peripheral area and the number of clicks were compared.

FIG. 17 shows changes in the X coordinate and the number of clicks of the position of the center of gravity of the back of subject D in Experiment 2. In FIG. 17, the vertical axis on the left side represents the moving distance (cm) of the center of gravity of the back in the X direction, the vertical axis on the right side represents the number of clicks (times), and the horizontal axis represents time (sec). Here, based on FIG. 1, the head direction is represented by a negative value and the foot direction is represented by a positive value from the reference position of the subject.

From FIG. 17, with respect to subject D, who responded significantly to both the outer peripheral area and the number of clicks, the center of gravity of the back was displaced in the head direction (arrows D1, D3, D4) before the number of clicks increased (for example, time T1, T3, T4). However, when the number of clicks exceeds the peak (for example, time T2), it can be seen that the position of the center of gravity of the back is displaced in the foot direction (arrow D2). This indicates that the center of gravity of the back is moving before the subject D feels the pain, and that the center of gravity of the back is displaced in the direction of the foot when the subject D is released from the pain. It was shown that the burden could be measured.

Further, from FIG. 17, it was found that the center of gravity of the back moves toward the head even in the process of increasing the number of clicks of pain. That is, the position of the back center of gravity of subject D is displaced in the head direction while the pain is increasing or continuing. When the subject felt pain during the treatment, it is considered that the center of gravity was moved upward (headward) as a whole by applying force to the upper back (for example, the head and shoulders). In this way, the displacement of the position of the center of gravity of the body is considered to represent the displacement of the mental burden level, and by analyzing the displacement of the outer peripheral area and the position of the center of gravity in combination, the physical and psychological burden of the subject can be more accurately measured. Can be measured.

The relationship between the displacement of the center of gravity of the subject, the outer peripheral area, and the number of clicks showed the same tendency for both the center of gravity of the back and the center of gravity of the buttocks.

FIG. 18 is a graph showing changes in the back weight w1, the buttocks weight w2, and the number of clicks of the subject in Experiment 2. The vertical axis on the left represents the weight of the back or buttocks (kg), the vertical axis on the right represents the number of clicks (times), and the horizontal axis represents time (sec). Regarding the weight, as the number of clicks increased, the measured value of the back weight w1 decreased and the measured value of the buttocks weight w2 increased. It is probable that when subject D felt pain, a force was applied to the upper back (for example, the neck and shoulders), and the center of gravity of the back moved significantly toward the head. At the same time, the center of gravity of the back is displaced toward the head, so that the area around the hips moves away from the dental chair unit 1 and the measured value of the weight w1 of the back decreases. It is probable that the body was supported by the buttocks and the measured value of the weight w2 of the buttocks increased. On the contrary, when the number of clicks indicating pain decreases, it is considered that the center of gravity of the back moves toward the legs of the body by releasing the tension and releasing the strength of the body. Although not shown, subject E, whose number of clicks was extremely small, had almost no change in the X and Y coordinates of the center of gravity of the back and the weights of the back and buttocks.

[Quantitative evaluation]
In order to quantitatively evaluate the mental and physical burden, the average value of the outer peripheral area of the locus of the back center of gravity before, during, and after the treatment for each measurement of Experiment 2 is summarized and shown in FIG. In addition, the standard deviation of the outer peripheral area of the locus of the back center of gravity before, during, and after the treatment for each measurement in Experiment 2 is summarized in FIG. Further, the outer peripheral area (percentage) of the locus of the back center of gravity during and after the treatment when compared with the outer peripheral area of the locus of the back center of gravity before the treatment in each measurement of Experiment 2 is shown in FIG. 21.

As shown in FIG. 19, in subject D, who had a strong pain response, the outer peripheral area of the locus of the dorsal center of gravity increased during and after the treatment as compared with before the treatment in all three measurements. Further, as shown in FIG. 20, in the subject D, the standard deviation of the outer peripheral area increased during and after the treatment as compared with before the treatment in all three measurements.

Then, as shown in FIG. 21, it was found that in subject D, the outer peripheral area changed about 2.5 times during the treatment as compared with that before the treatment. In other words, it can be said that the back center of gravity moved significantly during the treatment as compared with before the treatment. On the contrary, in subject E, who had a weak pain response, it was found that the outer peripheral area of the locus of the posterior center of gravity changed by about 8% during the treatment as compared with before the treatment.

Therefore, for example, the threshold value is set to 2.5 times the outer peripheral area before the treatment, and it is determined that the subject feels pain when the outer peripheral area exceeds this threshold value. In addition, as a subjective evaluation, the average value of the number of clicks of pain was set as a threshold value, and when the number of clicks exceeded this threshold value, it was determined that the subject was feeling pain. The judgment success rate was calculated by regarding the case where the objective evaluation and the subjective evaluation using the sway of the center of gravity exceeded the threshold value at the same time and the case where the threshold value was not exceeded at the same time. The results are shown in the table of FIG.

Further, as shown in FIG. 22, in this experiment, the judgment success rate was about 65% as a whole (subjects D and E). If only subject D who felt pain well was narrowed down, the judgment success rate was about 67%. On the other hand, in subject E, the outer peripheral area of the locus of the back center of gravity during treatment did not exceed 2.5 times the outer peripheral area before treatment, so that the threshold value of subject E was set to a value different from the threshold value of subject D. You may consider setting it.

According to the above-described embodiment, the pain condition of the subject and the mental burden associated therewith can be measured based on the measurement results of the body sway before and after the treatment of the subject. That is, according to the present embodiment, unlike Patent Document 1, it is not necessary to prepare a database for storing a known mental / physical state index corresponding to the mental / physical state in advance, and the subject is based on the measurement result of the body sway of the subject with a simpler configuration. It is possible to measure the physical and mental burden of.

For example, according to the present embodiment, the mental state and pain status of a patient undergoing dental treatment are objectively measured using the measurement data (time-series data) of the center of gravity sway measuring device, and the dentist is informed during the treatment. Since the results can be communicated (see, for example, FIG. 8), the dentist can proceed with the treatment smoothly, and the dentist can continue or postpone the treatment according to the patient's condition based on the result of the measurement. Or, since it is possible to decide to discontinue or the like, there is also an effect that it is possible to change the treatment method such as suspending the treatment and giving anesthesia. In the above-described embodiment, dental treatment has been described as an example, but it can also be applied to other treatment actions.

Further, in the present embodiment, the cushions 8 and 9 were placed on the center of gravity sway measuring devices 4 and 5 respectively through the experiments 1 and 2 to perform the measurement. The effect was not seen in the measurement data, and it was found that the mental and physical burden can be measured even if a cushion is placed on the center of gravity sway measuring device. Therefore, it is possible not only to place the center of gravity sway measuring device on the dental chair unit 1 or the like, but also to incorporate the center of gravity sway measuring device into the unit for measurement.

In endoscopy, which uses a medical camera (fiberscope) to observe the inside of the gastrointestinal tract such as the stomach, the patient is examined in the lateral decubitus position. Even when such a patient is in the lateral decubitus position, the physical and psychological burden of the patient can be measured by the physical and mental burden measuring system 30 including the body sway measuring devices 4 and 5 according to the present embodiment.

<Modification example>
The mental and physical burden measuring system 30 according to the above-described embodiment can also be used to measure the mental and physical burden of a subject in a sitting state. FIG. 23 is a top view and a side view showing an example of a unit structure (for example, a chair) that maintains a sitting state of a subject. The chair 80 shown in FIG. 23 is composed of a seat surface portion 82 and a backrest 83. Similar to the dental chair unit 1, the plate 6 is installed on the seat surface portion 82, and the center of gravity sway measuring device 4 is arranged on the plate 6. Further, a cushion 8 is arranged on the center of gravity sway measuring device 4. The information processing device 20 measures the physical and psychological burden of the subject based on the measurement data of the center of gravity sway measuring device 4 arranged on the seat surface portion 82.

According to the above-described modification, it is possible to measure the physical and mental burden of a person in a sitting position. For example, it is possible to take appropriate measures such as encouraging a worker sitting on a chair to stop the work or take a break.

Further, in the above-described embodiment, the example in which the threshold value is set from the outer peripheral area or the locus length of the locus of the center of gravity sway before and during the treatment has been described, but the threshold value may be set during the actual treatment. For example, treatment is performed using the default threshold value for 1 minute from the start of treatment, and the threshold value is calculated from the measurement data obtained from the body sway measuring device and the number of clicks in this 1 minute. Thereby, the threshold value can be set according to the patient based on the measurement data during the treatment. It should be noted that the threshold value may be set based only on the measurement data of the center of gravity sway measuring device without using the number of clicks.

Further, in the above-described embodiment or modification, the measurement of the physical and psychological burden of the subject in the supine or sitting position has been described, but the above-described embodiment is used for measuring the physical and mental burden of the subject in the lateral decubitus position. It can be used. When determining the physical and psychological burden of a subject by adding the displacement of the subject's center of gravity to the evaluation index (outer circumference area, trajectory length) according to the subject's center of gravity sway for the subject in the lateral decubitus position, the center of gravity is mainly used. The moving direction of the position may be the Y direction (see FIG. 1) instead of the X direction. Therefore, when the displacement of the center of gravity is added to the measurement of the physical and psychological burden, it is necessary to determine the physical and mental burden based on the moving direction of the center of gravity and the evaluation index according to the supine or lateral decubitus position of the subject. is there.

Further, although the mental and physical burden measuring system 30 is composed of the dental chair unit 1 and the information processing device 20, the information processing device 20 may be incorporated in the dental chair unit 1. The result measured by the information processing device 20 incorporated in the dental chair unit 1 is output to a display device or a tablet terminal equipped with a short-range wireless communication I / F by short-range wireless communication. In addition, as a configuration in which the measurement data of the center of gravity sway measuring device is transmitted to a server connected to the network, the server measures the physical and mental burden of the subject, and the measurement result is supplied from the server to the display device via the network. May be good.

Furthermore, the present invention is not limited to the above-described embodiments, and it goes without saying that various other application examples and modifications can be taken as long as the gist of the present invention described in the claims is not deviated. is there.

For example, the above-described embodiment describes the configuration of the apparatus and the system in detail and concretely in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the components described. It is also possible to add, delete, or replace other components with respect to a part of the configuration of the above-described embodiment.

Further, each of the above-mentioned components, functions, processing units and the like may be realized by hardware in part or all of them, for example, by designing an integrated circuit. Further, each of the above components, functions, and the like may be realized by software by the processor interpreting and executing a program that realizes each function.

1 ... Dental chair unit, 2 ... Seat surface, 3 ... Back, 4, 5 ... Center of gravity sway measuring device, 6, 7 ... Plate, 8, 9 ... Cushion, 11-14 ... Load sensor, 20 ... Information processing device , 21 ... Control device, 22 ... Memory, 23 ... Non-volatile recording device, 24 ... Display device, 25 ... Input device, 26 ... Short-range wireless communication I / F, 27 ... Network I / F, 30 ... Physical and mental burden measurement System, 50 ... Display screen, 60 ... Outer circumference, 70 ... Indicator, 80 ... Chair, 82 ... Seat surface, 83 ... Backrest, 211 ... Center of gravity position processing unit, 212 ... Burden measurement processing unit, 213 ... Number of operations measurement unit, 214 … Output processing unit, s… outer peripheral area, Sr1, Sr2… divided area

Claims (9)

A center-of-gravity sway measuring device that is arranged so that the position of the center of gravity of a subject in a supine or sitting position can be measured and outputs time-series data of the position of the center of gravity of the subject.
From the time-series data of the center of gravity position of the subject output by the center of gravity sway measuring device, a center of gravity position processing unit that calculates the value of the evaluation index according to the center of gravity sway of the subject.
A burden measurement processing unit that measures the physical and psychological burden of the subject based on the time change of the value of the evaluation index calculated by the center of gravity position processing unit.
It is provided with an output processing unit that outputs the result of measurement by the burden measurement processing unit .
The burden measurement processing unit compares the value of the evaluation index calculated by the center of gravity position processing unit with a predetermined threshold value, and based on the comparison result and the moving direction of the center of gravity of the subject, the physical and psychological burden of the subject. A mental and physical burden measurement system that determines . The first aspect of claim 1, wherein the center of gravity position processing unit calculates the outer peripheral area of the locus of the center of gravity for each predetermined time length from the time series data of the center of gravity position of the subject as an evaluation index according to the sway of the center of gravity of the subject. Physical and mental burden measurement system. The first aspect of claim 1, wherein the center-of-gravity position processing unit calculates the length of the locus of the center of gravity for each predetermined time length from the time-series data of the position of the center of gravity of the subject as an evaluation index according to the sway of the center of gravity of the subject. Physical and mental burden measurement system. The mental and physical burden measurement system according to claim 2 or 3, wherein the evaluation index according to the sway of the center of gravity of the subject is calculated in an evaluation section having a predetermined time length for each set time. The mental and physical burden measuring system according to any one of claims 1 to 4 , wherein the center of gravity sway measuring device is arranged in a unit structure that maintains a supine or sitting position of the subject. The mental and physical burden measuring system according to any one of claims 1 to 4 , wherein the center of gravity sway measuring device is attached to a chair or a chair with a movable backrest. The mental and physical burden measuring system according to claim 6 , wherein the center of gravity sway measuring device is attached to a position of the chair with a movable backrest where the weight of the back of the subject is applied. It is a method of measuring the physical and mental burden of a subject using an information processing device that measures the physical and mental burden of the subject.
From the time-series data of the center of gravity position of the subject output by the center of gravity sway measuring device arranged so that the center of gravity position of the subject in the supine or sitting position can be measured by the center of gravity position processing unit , the subject's center of gravity sway is adjusted. Center of gravity position processing to calculate the value of the evaluation index
The burden measurement process for measuring the physical and psychological burden of the subject based on the time change of the value of the evaluation index by the burden measurement processing unit ,
The output processing unit, seen including and an output process of outputting the result of the measurement,
In the burden measurement process, the value of the evaluation index calculated by the center of gravity position processing unit is compared with a predetermined threshold value, and the physical and psychological burden of the subject is determined based on the comparison result and the moving direction of the center of gravity of the subject. Method of measuring physical and mental burden to judge . A center-of-gravity sway measurement procedure in which the position of the center of gravity of a subject in a supine or sitting position is measurable and time-series data of the position of the center of gravity of the subject is output.
From the time-series data of the center of gravity position of the subject, the center of gravity position processing procedure for calculating the value of the evaluation index according to the sway of the center of gravity of the subject, and
A burden measuring procedure for measuring the physical and mental burden of the subject based on the time change of the value of the evaluation index, and
The output procedure for outputting the measurement results and
In the burden measurement procedure, the value of the evaluation index calculated in the center of gravity position processing procedure is compared with a predetermined threshold value, and the physical and psychological burden of the subject is determined based on the comparison result and the moving direction of the center of gravity of the subject. Judgment procedure and
A program that lets your computer run.

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