Patent Publication Number: US-2005137503-A1

Title: Massage machine and physiological quantity measuring circuit for use in the machine

Description:
FIELD OF THE INVENTION  
      The present invention relates to massage machines adapted to give one or some kinds of massages to various parts of the user, and more particularly to massage machines for health care which are adapted for the health care of the user and to physiological quantity measuring circuits for use in the massage machine which are adapted to detect physiological quantities of the autonomic nervous system of the user by physiological quantity sensors such as a skin temperature sensor and perspiration quantity sensor and to thereby control the massage operation of the machine based on the detected physiological quantities.  
     BACKGROUND OF THE INVENTION  
      With reference to  FIG. 1 , massage machines generally comprise a chair body  10  including legs  11 , a seat  12 , a backrest  13  and a pair of opposite armrests  14 ,  14 , and a massage mechanism  2  having a plurality of therapeutic members  21  and incorporated into the body  10 . The therapeutic members  21  are reciprocatingly moved up and down while being vibrated, whereby the human body is massaged.  
      The massage machines of the type mentioned include one which is adapted to detect a stiff body part before giving a massage so as to massage the most appropriate part concentrically [JP-A No. 9-75413(1997)]. This machine is capable of giving a massage concentrically to the stiff part of the user.  
      However, the conventional machine is unable to detect the psychological state of the user such as “comfort” or “pain,” is therefore unable to detect whether the condition of the user&#39;s health is improved by an effective massage actually given to the user, and further has the problem of failing to give an effective massage for realizing an enhanced degree of relaxation or increased refreshment.  
      Accordingly, a massage machine is proposed which is adapted to detect physiological quantities (relaxation indicating factors) of the person to be massaged, such as pulse, skin temperature and galvanic skin response (GSR), for controlling a massage mechanism in accordance with the degree of relaxation of the person [JP-A No. 6-209(1994)]. In giving a specified massage to a particular part, the massage machine is capable of detecting the psychological state of the user by monitoring variations in physiological quantities of the user, so that an effective massage can be performed to realize an increased degree of relaxation or refreshment.  
      Massage machines give different kinds of massages, such as tapping, kneading, combination of these movements and rolling, to a plurality of parts such as the shoulder, back, waist and leg. Different parts massaged and different kinds of massages given produce different variations in the physiological quantities of the user. When massages are given to various body parts, variations in the skin temperature or GSR of the person massaged are detected, and the psychological state of the user as given each massage at a particular part is detected based on the variation.  
      However, a sufficiently high correlation is not always available between the psychological state detected by performing a certain massage by the conventional machine on a particular part of the user and the psychological state subjectively explained by the user. Consequently, the machine has the problem of failing to give effective massages.  
     SUMMARY OF THE INVENTION  
      A first object of the present invention is to provide a massage machine for health care which is capable of judging whether the massage given to the user serves to improve the condition of the user&#39;s health and utilizing the result of judgement as guidelines for health care.  
      A second object of the present invention is to provide a physiological quantity measuring circuit for use in a massage machine adapted to give different kinds of massages to various parts of the user, the circuit being capable of accurately detecting the psychological state of the user from the user&#39;s physiological quantities.  
      To fulfill the first object, the present invention provides a massage machine for health care comprising a living body information sensor for detecting the living body information of the autonomic nervous system of the person to be massaged, means for judging the psychological state of the person based on the living body information detected, and means for holding histories of psychological states of persons to be massaged.  
      The massage machine of the invention is adapted to judge the psychological state of the person to be massaged, such as “comfort” or “pain,” based on the living body information of the autonomic nervous system of the person, so that the physical condition of the person can be detected with reference to the history of psychological state judged. For example, if the psychological state of having “pain” continues, this indicates that the physical condition is not remedied despite the massage, while if the psychological condition changes from “pain” to “comfort,” this indicates the amelioration of the physical condition. Accordingly, it is possible to judge whether the condition of the person&#39;s health is improved by the massage given and to utilize the result of judgement as guidelines for health care.  
      Stated more specifically, the living body information sensor includes one or more sensors selected from among a GSR (galvanic skin response) sensor, a pulse sensor and a skin temperature sensor. It is known that the living body information detected by these sensors varies with the degree of relaxation or tension. When in a relaxed condition, the person exhibits a low activity value, while when tense, he exhibits a high value in activity. Accordingly, the psychological state of the person, such as a sensation of stiffness or physical condition, can be estimated with high reliability from the variations in the living body information detected by these sensors.  
      For example, when the living body information sensor comprises a pulse sensor, a drop in the pulse rate can be interpreted as indicating a relaxed state (“comfortable” state), whereas a rise in the pulse rate can be interpreted as indicating a tense state (state of having “pain”). Alternatively when the living body information sensor comprises a skin temperature sensor, a rise in skin temperature can be interpreted as indicating a relaxed state, while a drop in the skin temperature a tense state. Further when the living body information sensor comprises a GSR sensor, a reduction in GSR can be interpreted as indicating a relaxed state, while a rise in GSR a tense state.  
      Further stated more specifically, the history holding means comprises means for counting the frequency with which the person is judged to be in a tense state when massaged at each of different body parts, and the count obtained by the counting means is held as a history of psychological state. A count which is relatively greater can be interpreted as indicating an impaired physical condition, while a count which is relatively smaller can be interpreted as conversely indicating an ameliorated physical condition. With an embodiment comprising means for displaying variations in the count involved in massaging particular one of the body parts, the tendency of variations in the count can be quantitatively determined, so that variations in physical condition can be judged more reliably.  
      Thus, the massage machine of the invention for health care is capable of judging whether the condition of the person&#39;s health is ameliorated by massages so as to utilize the result of judgement as guidelines for health care.  
      In order to accomplish the second object, we have clarified why the conventional massage machine fails to provide a sufficiently high correlation between the psychological state detected by giving a certain massage to a particular part of the user and the psychological state subjectively explained by the user, as will be described below. With the conventional massage machine, the output signal of a thermistor for detecting the skin temperature is converted to voltage by one signal detector, and the output signal of a GSR electrode for detecting the quantity of perspiration is converted to voltage by one signal detector, detecting variations in skin temperature or GSR based on the output signals of the two signal detectors. These signal detectors need to produce a required output voltage over a wide range in conformity with variations in skin temperature or GSR, and therefore have such signal conversion characteristics that the variations in output signal are small relative to variations in input signal, failing to achieve sufficiently high detection accuracy.  
      For example, variations are greater in skin temperature than in body temperature, so that when it is attempted to obtain an output voltage in the range of 0 V to 5 V for the range of 15° C. to 38° C., the signal conversion characteristics are 0.22 V per degree C. Further in the case of GSR, variations are as great as tens of kiloohms to thousands of kiloohms, and when a sufficient output voltage is to be obtained over such a wide range, the signal conversion characteristics become nonlinear. Although relatively great output voltage variations are available, for example, over the range of 0 to 1000 kΩ, output voltage variations for about 2000 kΩ are much smaller than for about 50 kΩ (for example, about {fraction (1/7)}), hence impaired measurement accuracy.  
      Improved measurement accuracy can be obtained by constructing the physiological quantity detecting circuit in a multiplicity of stages to obtain different kinds of signal conversion characteristics which differ in the relationship of the output signal to the input signal as shown in  FIG. 15  or  16  for the selective use of appropriate kind of signal conversion characteristics in accordance with the magnitude of input signal, so that each kind of signal conversion characteristics involves increased variations in output signal relative to the input signal.  
      However, when this method is used, it is likely that the signal conversion characteristics will be changed over from one kind to another for use in signal conversion processing in accordance with a variation of input signal while giving same kind of massage to the same part. Since different kinds of signal conversion characteristics involve different errors, the difference in error then appears as a variation in output signal to result in lower accuracy in measuring physiological quantities.  
      Accordingly, the physiological quantity measuring circuit for use in the massage machine of the invention comprises a physiological quantity detection circuit for converting an output signal from a physiological quantity sensor to a physiological quantity detection signal. The detection circuit comprises a plurality of signal converters exhibiting different kinds of signal conversion characteristics which are different in the relationship of the output signal with the input signal. These different kinds of signal conversion characteristics overlap each other with respect to the range of input signals to be processed by the converter for signal conversion.  
      The measuring circuit comprises a signal processing circuit for producing physiological quantity data based on a physiological quantity detection signal obtained from the detection circuit. The signal processing circuit produces a series of items of physiological quantity data in the process of giving the same massage to the same body part based only on physiological quantity detection signals resulting from one of the different kinds of signal conversion characteristics of the detection circuit when the resulting detection signals are all included within an effective output range of said one kind of signal conversion characteristics, or to produce a series of items of physiological quantity data in the process based on physiological quantity detection signals resulting from one kind of or the different kinds of signal conversion characteristics when otherwise.  
      With the measuring circuit of the invention, the physiological quantity detection signals obtained in the process of giving the same massage to the same body part may result from the different kinds of signal conversion characteristics of the detection circuit, but insofar as these signals are included in the effective output range of one kind of conversion characteristics, a series of physiological quantity data in the process is produced based on the detection signals converted by the same kind conversion characteristics. Thus, detection of physiological quantities due to a changeover of signal conversion characteristics is suppressed to prevent impairment of measuring accuracy due to the characteristics changeover.  
      Stated more specifically, the physiological quantity sensor is a skin temperature sensor for measuring skin temperature, and the physiological quantity detection circuit has two kinds of signal conversion characteristics respectively for low temperatures and high temperatures which partly overlap each other in the temperature range to be measured. In this case, the signal processing circuit produces a series of items of skin temperature data in the process of giving the same massage to the same body part based only on physiological quantity detection signals resulting from the low-temperature signal conversion characteristics when said resulting detection signals are all included within the effective output range of the low-temperature signal conversion characteristics, or to produce a series of items of skin temperature data in the process based on physiological quantity detection signals resulting from the two kinds of signal conversion characteristics for high and low temperatures when otherwise.  
      The physiological quantity sensor is a perspiration quantity sensor for measuring the resistance value between a pair of electrodes, and the physiological quantity detection circuit has two kinds of signal conversion characteristics respectively of low gain and high gain which overlap each other in the range of resistance values to be measured. In this case, the signal processing circuit produces a series of items of perspiration quantity data in the process of giving the same massage to the same body part based only on physiological quantity detection signals resulting from the high-gain signal conversion characteristics when said resulting detection signals are all included within the effective output range of the high-gain signal conversion characteristics, or to produce a series of items of perspiration quantity data in the process based on physiological quantity detection signals resulting from the low-gain signal conversion characteristics when otherwise.  
      The physiological quantity measuring circuit of the invention for use in the massage machine detects physiological quantity of the user with high accuracy, making it possible to accurately detect the psychological state of the user and to give an effective massage. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view showing a health care massage machine of the invention in use;  
       FIG. 2  is a perspective view showing the appearance of a remote controller;  
       FIG. 3  is a diagram showing an exemplary representation on a display of the remote controller;  
       FIG. 4  is a block diagram showing the construction of a control system for the massage machine;  
       FIG. 5  is a diagram for illustrating the relationship between variations in living body information and psychological states;  
       FIG. 6  is a diagram for showing rules for judging psychological states from variations in living body information;  
       FIG. 7  is a flow chart for showing a procedure for judging the sensation of stiffness;  
       FIG. 8  is a flow chart showing a procedure for judging psychological states;  
       FIG. 9  is a flow chart showing a procedure for displaying a history of results obtained by judging the sensation of stiffness and result of diagnosis;  
       FIG. 10  is a graph showing variations in the count of degree of stiffness;  
      FIGS.  11 ( a ) and  11 ( b ) are graphs showing the results of regression analyses of subjective values and estimated values, respectively, of stiffness degrees;  
       FIG. 12  is a block diagram showing the construction of a physiological quantity measuring circuit for use in the massage machine of the invention;  
       FIG. 13  is a diagram showing the construction of a skin temperature detection circuit;  
       FIG. 14  is a diagram showing the construction of GSR detection circuit;  
       FIG. 15  is a graph showing the signal conversion characteristics of the skin temperature detection circuit;  
       FIG. 16  is a graph showing the signal conversion characteristics of the GSR detection circuit;  
       FIG. 17  is a flow chart showing a procedure for measuring the skin temperature; and  
       FIG. 18  is a flow chart showing a procedure for measuring GSR. 
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS  
      Embodiments of the invention will be described below in detail with reference to the drawings.  
      Massage Machine for Health Care  
      With reference to  FIG. 1 , the massage machine of the present invention for health care comprises a chair body  10  including legs  11 , a seat  12 , a backrest  13  and a pair of opposite armrests  14 , and a massage mechanism  2  having a plurality of therapeutic members  21  and incorporated into the chair body  10 . The machine gives a massage to the human body by reciprocatingly moving the therapeutic members  21  up and down while vibrating these members  21 . The massage machine can be operated by manipulating a remote controller  7  as shown.  
      With reference to  FIG. 2 , the remote controller  7  comprises a display  71  and a plurality of manual buttons  72  arranged on the front side of a vertical casing  70 . Arranged on the right side face of the casing  70  are a pulse sensor  52  comprising a light-emitting element and light-receiving element, and a skin temperature sensor  53  comprising a thermistor. A GSR sensor  51  comprising a pair of electrodes  51   a ,  51   b  is disposed on opposite side faces of the casing  70 . When the controller  7  is grasped with the left hand as indicated in chain lines, the forefinger comes into contact with the skin temperature sensor  53 , the middle finger with the pulse sensor  52 , the ring finger and the little finger with the electrode  51   b  of the GSR sensor  51  and the palm with the other electrode  51   a  of the GSR sensor  51 .  
      As seen in  FIG. 3 , the display  71  of the remote controller  7  shows the part being massaged, degree of stiffness, degree of comfort, position of the stiff part, etc. Further as shown in  FIG. 9 , variations in the count indicating the degree of stiffness are displayed upon a changeover of the screen.  
       FIG. 4  shows the construction of a control system for the massage machine. A living body information sensor  5  comprising the GSR sensor  51 , pulse sensor  52  and skin temperature sensor  53  is connected to input ports of a control circuit  6  comprising a microcomputer. The display  71  and the massage mechanism  2  are connected to output ports of the control circuit  6 . A memory  61  is connected also to the control circuit  6 .  
       FIG. 5  shows the relationship between the living body information detected by the living body information sensor  5 , i.e., GSR, skin temperature and pulse rate and the psychological state of the person to be massaged (user). As illustrated, the GSR, skin temperature and pulse rate vary in different modes with the degree of activity of the autonomic nervous system. When the degree of activity is low, GSR and pulse rate lower and the skin temperature rises. When the degree of activity is slightly low, GSR remains unchanged, but the skin temperature rises and the pulse rate drops. If the degree of activity is slightly high, GSR rises from the constant level, the skin temperature lowers and the pulse rate rises. Further when the degree of activity is high, GSR greatly rises, the skin temperature drops and the pulse rate increases.  
      As the psychological states of the user in the event of such variations in the living body information, it is speculated that the user is in a relaxed comfortable state when the degree of activity is low, or that the user feels such a unique sensation as is experienced when massaged at a stiff part, feeling both pain and comfort as mingled therewith (“active” state), when the degree of activity is slightly high, or that the user feels a pain when the degree of activity is high. When the degree of activity is neutral, the user will presumably be in a neutral state, feeling neither comfort nor pain.  
       FIG. 7  shows a procedure to be executed by the control circuit  6  for judging the sensation of stiffness. The degree of stiffness for various body parts is initialized first in step S 21 , and the position of the therapeutic members is adjusted to one of the shoulder, back, waist and leg in step S 22 . Subsequently in step S 23 , various massages, i.e., kneading, tapping, combination of kneading and tapping, and rolling, are performed to measure physiological quantities (skin temperature, GSR and pulse rate) during these massage processes. The psychological state (pain, active, neutral or relaxed) is judged in step S 24  by the procedure to be described below.  
      Subsequently, step S 25  inquires whether the result of judgement is “pain” or “active,” and if the answer is affirmative, the degree of stiffness of the massaged part is counted, followed by step S 27 , which inquires whether the massages have been performed for all the body parts.  
      If the inquiry of step S 27  is answered in the negative, step S 22  follows again. When the answer is affirmative, step S 28  follows to judge the sensation of stiffness for each part. If the count of stiffness degree is greater than A serving as a threshold value, this is interpreted as indicating stiffness sensed. If otherwise, the judgement that no stiffness is sensed is made. The results of judgement thus made are stored in the memory  61 . The sequence thereafter proceeds to step S 29 , in which the results of judgement are presented on the display  71 .  
       FIG. 8  shows a procedure for judging the psychological state (pain, active, neutral or relaxed). First in step S 1 , waveform is received from the GSR sensor to inquire whether the waveform, for example, resulting from release of the hand from the sensor is found abnormal. If the answer is affirmative, “abnormal” is displayed in step S 2 . When the waveform is found normal, step S 3  follows for noise removal processing. The sequence then proceeds to step S 4  to detect variations of GSR in each phase section (each massage movement). Slope can be detected, for example, by calculating the slope of GSR variations by least square approximation.  
      Further in step S 5 , waveform is received from the skin temperature sensor and checked for abnormality. If it is found abnormal, “abnormal” is displayed in step S 6 . When the waveform is found normal, step S 7  follows for noise removal processing. The pulse rate is then detected in step S 8 . The sequence then proceeds to step S 9  to detect variations of pulse rate in each phase section. Slope can be detected, for example, by calculating the slope of pulse rate variations by least square approximation.  
      Further in step S 10 , waveform is received from the skin temperature sensor and checked for abnormality. If it is found abnormal, “abnormal” is displayed in step S 11 . When the waveform is found normal, step S 12  follows for noise removal processing. The sequence then proceeds to step S 13  to detect variations of the skin temperature in each phase section. Slope can be detected, for example, by calculating the slope of skin temperature variations by least square approximation.  
      After the execution of steps S 4 , S 9  and S 13 , step S 14  follows to determine “pain,” “active,” “neutral” or “relaxed” from combinations of GSR variations ΔG, skin temperature variations ΔT and pulse rate variations ΔH shown in  FIG. 6 . Incidentally,  FIG. 6  shows the estimation of psychological states based on the relationship of  FIG. 5  as formulated.  
      Subsequently step S 15  of  FIG. 8  displays on the remote controller the result of judgement of the psychological state in each phase (each massage movement). After repeating steps S 4 , S 9 , S 13 , S 14  and S 15  a number of times for the repetitions of all the phases, the sequence proceeds to step S 16 , in which an overall “sensation of stiffness” is judged from the results of judgement in all phases, and the final result is displayed on the display  71  to complete the procedure. The result of judgement in each phase is stored in the memory  61 .  
      With the massage machine described, the remote controller  7  is manipulated to update the history of results of judgement of stiffness sensation and present on the display  71  the result obtained by diagnosing the condition of the user&#39;s health based on the history.  FIG. 9  shows this procedure. The history of results of stiffness sensation judgement is read from the memory  61  first in step S 31 , the sensation of stiffness is judged in step S 32 , and the history is thereafter updated in step S 33 . The variation of physical condition of the user is diagnosed in step S 34  based on the tendency of variations in the history. The history and the result of diagnosis are displayed in step S 35 .  
       FIG. 10  shows an exemplary representation of tendency of variations in the history of results of stiffness sensation judgement. In the illustrated example, count values of degrees of stiffness in the shoulder in the morning (before work), as indicated in a solid line and count values of corresponding stiffness degrees in the evening (after work), indicated in a broken line show a rising tendency, revealing an increase in the sensation of shoulder stiffness especially in the evening. A high correlation found between the subjective values of shoulder stiffness degree and the count values thereof further shows that the method of judging the sensation of stiffness accordingly to the invention is reasonable.  
      FIGS.  11 ( a ) and  11 ( b ) are graphs showing the results of regression analyses of subjective values (0 to 100) of stiffness degrees and estimated stiffness degrees (counts) for the sensation of shoulder stiffness and lumbago, respectively. These graphs also reveal a high correlation between the subjective values of stiffness degrees and the estimated values thereof, thus substantiating the reasonability of the stiffness sensation judging method of the invention.  
      Thus, the massage machine embodying the present invention for health care is adapted to diagnose variations in the physical condition of the user by massaging various body parts, for example, from the tendency of variations in the counts of stiffness in the shoulder as shown in  FIG. 10 . The result of diagnosis can be utilized as guidelines for health care.  
      Physiological Quantity Measuring Circuit for Massage Machine  
      With the massage machine of the present invention, the massage mechanism  2  has its operation controlled by a microcomputer  105  as shown in  FIG. 12 . A thermistor  101  for measuring the skin temperature and GSR electrodes  102  for measuring the quantity of perspiration are worn, for example, on finger tips of the user. The thermistor  101  is connected via a skin temperature detection circuit  103  to the microcomputer  105 . The GSR electrodes  102  are connected to the microcomputer  105  via a GSR detection circuit  104 . The skin temperature detection circuit  103  comprises a high skin temperature detector  131  and a low skin temperature detector  132 . The GSR detection circuit  104  comprises a GSR detector  141  and a second amplifier  142 .  
       FIG. 13  shows the construction of the skin temperature detection circuit  103  in detail. Variations in the resistance value of the thermistor  101  due to variations in skin temperature are converted to voltage variations by the high skin temperature detector  131  and low skin temperature detector  132 , which produce a high temperature detection signal and a low temperature detection signal, respectively.  
       FIG. 15  shows the relationship (signal conversion characteristics) A between the input signal (temperature) of the high temperature detector  131  of the circuit  103  and the output signal (voltage) thereof, and the relationship (signal conversion characteristics) B between the input signal (temperature) of the low temperature detector  132  of the circuit  103  and the output signal (voltage) thereof. The two kinds of signal conversion characteristics overlap each other at around 27° C. The two kinds of signal conversion characteristics A, B for high temperatures and low temperatures each provide effective output voltages in the range of up to 4.75 V, and are greater in slope than in the prior art.  
       FIG. 14  shows the construction of the GSR detection circuit  104  in detail. Variations in the resistance value between the pair of GSR electrodes  102  due to variations in the quantity of perspiration are converted to voltage variations first by the GSR detector  141 , and the voltage variations are further amplified by the second amplifier  142 . Thus, these components  141 ,  142  deliver a low gain GSR detection signal and a high gain GSR detection signal, respectively.  
       FIG. 16  shows the relationship (signal conversion characteristics) C between the input signal (resistance) of the GSR detector  141  of the GSR detection circuit  104  and the output signal (voltage) thereof, and the relationship (signal conversion characteristics) D between the input signal (resistance) of the second amplifier  142  of the circuit  104  and the output signal (voltage) thereof. The two kinds of signal conversion characteristics overlap each other at resistance values of not lower than 725 kΩ. The two kinds of low gain and high gain signal conversion characteristics C, D each provide effective output voltages in the range of up to 4.75 V. Within the range of effective output voltages, the high gain characteristics exhibit a greater slope than the low gain characteristics.  
       FIG. 17  shows the skin temperature measuring procedure to be performed by the microcomputer  105 . When a physiological quantity judging mode is selected first in step S 1 , the kneading balls are moved to the first part to be massaged in step S 2 , and a data collecting procedure is thereafter performed in step S 3 . Stated more specifically, when a particular massage is started on the specified part, step S 31  follows to start to measure the skin temperature by the skin temperature sensor (thermistor), and data (voltage values) obtained by the signal conversion characteristics for high temperatures and the signal conversion characteristics for low temperatures is collected at an interval of 10 mS. When one massage operation is completed upon lapse of about 15 sec, the measurement is completed in step S 32 , and 1500 items of data for each of the high temperature side and the low temperature side are stored in the memory.  
      Subsequently, during the shift of the kneading balls to the next part to be massaged, the data is processed in step S 4 . First, the data obtained during the first 5-sec period is discarded in step S 41 . In step S 42 , an average is obtained from the data available during each second to hold ten items of data for each of the high and low temperature sides. An inquiry is then made in step S 43  as to whether the items of low-temperature data are all in the effective output voltage range of up to 4.75 V shown in  FIG. 15 . When the answer is affirmative, step S 45  follows to detect variations in skin temperature based on the low-temperature data, detect the physiological reaction based on the result of detection and output the final result.  
      If the answer to the inquiry of step S 43  is negative, on the other hand, the data within the effective output range is selected from among the low-temperature and high-temperature data in step S 44  to obtain a series of data items to detect variations in skin temperature from the data, detect the physiological reaction from the result of detection and output the final result. All the data is thereafter deleted in step S 46 . Simultaneously with the start of a massage on the next part to be massaged, step S 31  follows again to start measurement with the skin temperature sensor.  
       FIG. 18  shows the GSR measuring procedure to be performed by the microcomputer  105 . When a physiological quantity judging mode is selected first in step S 5 , step S 6  checks whether fingers comes into contact with the GSR electrodes with reference to GSR output. If the output is not smaller than 0.5 mV, this indicates contact. The kneading balls are moved to the first part to be massaged in step S 7 , and a data collecting procedure is then performed in step S 8 . Stated more specifically, when a particular massage is started on the specified part, step S 81  follows to start to measure GSR by the GSR sensor (GSR electrodes), and data (voltage values) obtained by the high-gain signal conversion characteristics and the low-gain signal conversion characteristics is collected at an interval of 10 mS. When the massage operation is completed upon lapse of about 15 sec, the measurement is completed in step S 82 , and 1500 items of data for each of the high gain side and the low gain side are stored in the memory.  
      Subsequently, during the shift of the kneading balls to the next part to be massaged, the data is processed in step S 9 . First in step S 91 , an average is obtained from the data available during each second to hold 15 items of data for each of the high and low gain sides. Discarded in the next step S 92  is the data obtained during the period (with an output of up to 0.5 V) in which the finger is out of contact with the electrodes. An inquiry is then made in step S 93  as to whether the items of high-gain data are all in the effective output voltage range of up to 4.75 V shown in  FIG. 16 . When the answer is affirmative, step S 95  follows to detect variations in GSR based on the high-gain data, detect the physiological reaction based on the result of detection and output the final result. If the answer to the inquiry of step S 93  is negative, on the other hand, step S 94  follows to detect variations in GSR based on the low-gain data, detect the physiological reaction from the result of detection and output the final result.  
      All the data is thereafter deleted in step S 96 . Simultaneously with the start of a massage on the next part to be massaged, step S 81  follows again to start measurement with the GSR sensor.  
      In measuring the skin temperature, the massage machine described above uses signal conversion characteristics having high sensitivity for both high temperatures and low temperatures as shown in  FIG. 15 . For measurement in the region of high temperatures, high-temperature signal conversion characteristics are used, while for measurement in the region of low temperatures, low-temperature signal conversion characteristics are used. This ensures higher measurement accuracy than in the prior art.  
      Further in measuring GSR, high-gain signal conversion characteristics are used in the region of high resistances in addition to low-gain signal conversion characteristics as shown in  FIG. 16  to assure higher measurement accuracy than conventionally. In giving the same massage to the same part for the measurement of skin temperature and GSR, physiological quantity detection data obtained by one kind of signal conversion characteristics is used to measure variations in the skin temperature and GSR insofar as this is feasible. This obviates errors to be involved in a changeover of signal conversion characteristics.