BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a portable device for continuously collecting information in time sequence about the living body of a wearer of the device in his or her daily life.  
           [0003]    2. Description of the Related Art  
           [0004]    It is widely known that living body information monitoring devices have been used to continuously measure living body information for the purpose of assistance in health care, diagnosis and treatment. For example, step counters capable of counting the number of steps made by a wearer in walking to determine the amount of exercise done by the wearer are in widespread use. In use of such step counters, measurement is continuously performed and measurement data is handled by being totalized, that is, the total number of walking steps in one day is used as an index of health care.  
           [0005]    U.S. Pat. No. 5,197,489 discloses an attempt to detect fine bodily movements of a wearer and to use data on detected bodily movements in treatments, etc. According to the specification of this patent, each kind of movement has a particular frequency characteristic. For example, the specific frequency of breathing ranges from 0.2 to 1 Hz; that of heartbeat, from 2 to 3 Hz; that of activities during the night, from 0.2 to 3 Hz; and that of tremors, from 2 to 9 Hz. A frequency signal corresponding to each of these particular movements is extracted by changing a filter constant, quantified and recorded in time sequence.  
           [0006]    Conventional living body information monitoring devices enable objective measurements of information on a daily or weekly basis about a living body, e.g., measurements of changes of bodily movements, changes in the amount of activity, heartbeat, body temperature, etc. However, they are incapable of obtaining subjective information, e.g., information from a person about the reason why the person was active, or mental information, e.g., information about a person&#39;s feeling when the person was active. Ordinarily, such subjective or mental information (hereinafter referred to collectively as mental information) is obtained by a doctor asking a patient questions about patient&#39;s health in consultation or asking the patient to fill in an inquiry form. It is possible to elicit information on the mental condition of a patient by asking the patient some questions in consultation or by using an inquiry form. However, it is very difficult to obtain detailed information by going back to the past and it is impossible to determine variation in mental information in correspondence with variation in living body information obtained. A patient may periodically fill in an inquiry form by always carrying it about with him or her to provide mental information in time sequence. However, such a process is troublesome and there is a possibility of the patient forgetting the inquiry form in his or her daily living. Moreover, the conventional method of separately obtaining living body information and mental information entails a drawback of missing important information since it does not enable timely questioning immediately after a change in living body information has occurred.  
         SUMMARY OF THE INVENTION  
         [0007]    An object of the present invention is to provide a portable living body information collector which is capable of continuously measuring living body information in daily life for the purpose of assistance in health care, diagnosis and treatment, which enables efficient collection of necessary mental information by timely questioning about health, and which can be worn on a human body.  
           [0008]    To achieve the above-described object, according to one aspect of the present invention, there is provided a portable device for collecting living body information, the device including a detection circuit for detecting living body information and for outputting a signal representing the detected information, storage means for storing the output signal from the detection circuit and for storing at least one question and an answer to the question, a display unit which displays the question, input means for inputting an answer to the displayed question, and a control circuit which makes the display unit display the question at a suitable time, and which stores, sequentially with respect to time, answers input by the input means. With the device, information of the living body of a wearer wearing the portable information collection device and the mental condition of the wearer obtained through the question can be collected in time sequence to be used for assistance in treatment.  
           [0009]    According to another aspect of the present invention, there is provided a method of collecting living body information, the method including the steps of averaging the latter half of 2N number of plurality of living body information items lately measured at predetermined internals sequentially with respect to time, averaging the former half of the 2N number of living body information items, and making a determination as to whether the difference between the average of the latter half of the 2N number of living body information items and the average of the former half of the 2N number of living body information items is larger than a predetermined threshold value, wherein questioning about health is performed if it is determined in the determination step that the difference between the averages is larger than the threshold value. This method enables determination as to whether a user to be treated is awake or asleep, and enables timely questioning when the user is awake. Information obtained in this manner can be used for treatment. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    In the accompanying drawings:  
         [0011]    [0011]FIGS. 1A and 1B are diagrams showing an external appearance of a portable living body information collector which represents an embodiment of the present invention;  
         [0012]    [0012]FIG. 2 is a diagram schematically showing a system in which the portable living body information collector of the embodiment and a personal computer are connected to each other and communication is performed therebetween;  
         [0013]    [0013]FIG. 3 is a diagram schematically showing the configuration of the portable living body information collector in the embodiment of the present invention;  
         [0014]    [0014]FIG. 4 is a block diagram showing the configuration of the portable living body information collector in the embodiment of the present invention;  
         [0015]    [0015]FIG. 5 is a diagram of a bodily movement detection circuit of the portable living body information collector in the embodiment of the present invention;  
         [0016]    [0016]FIG. 6 is a diagram showing a waveform of an output from the bodily movement detection circuit of the portable living body information collector in the embodiment of the present invention;  
         [0017]    [0017]FIG. 7 is a flowchart of a procedure for setting in the portable living body information collector in the embodiment of the present invention;  
         [0018]    [0018]FIG. 8 is a flowchart of the operation of the portable living body information collector in the embodiment of the present invention;  
         [0019]    [0019]FIG. 9 is another flowchart of the operation of the portable living body information collector in the embodiment of the present invention; and  
         [0020]    [0020]FIGS. 10A and 10B are graphs showing the results of measurement with the portable living body information collector in the embodiment of the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0021]    An embodiment of the present invention will be described with reference to the accompanying drawings. FIGS. 1A and 1B are a plan view and a side view, respectively, of an external appearance of a portable living body information collector  100  which represents an embodiment of the present invention. The portable living body information collector  100  is constituted by a main unit  101  and a pair of band members  108  and  109 . The portable living body information collector  100  can be worn about a wrist of a wearer with the band members  108  and  109  fitted around the wrist. The main unit  101  has a display  102  and a plurality of keys  103 ,  104 ,  105 ,  106 , and  107 . The display portion  102 , which is, for example, a liquid crystal display (LCD), can be normally used as a wristwatch by being made to display time information. Simple questions such as “How are you feeling?” and “Are you irritated?” are displayed on the display portion  102  at suitable times. The wearer inputs an answer to each question by using the key  107 . In this embodiment, the key  107  is an input device of five directions: upward, downward, rightward, leftward, and depressing directions. For example, to answer to the question “How are you feeling?”, the wearer inputs the level of feeling at the corresponding time by operating the key  107  in the leftward or rightward direction. In the example shown in FIG. 1, a bar indicator on the display portion  102  changes in length according to the input operation in the leftward or rightward direction, and the input is determined by the depressing operation. The other keys  103 ,  104 ,  105 , and  106  are used to realize other functions, e.g., a mode change function and a time correction function, which do not directly relate to the present invention and, therefore, will not be described in this specification. Input/output terminals  110 ,  111 , and  112  for connection to an external personal computer or the like are formed in a side surface of the main unit  101 .  
         [0022]    [0022]FIG. 2 is a diagram schematically showing a system in which communication is performed between the portable living body information collector  100  and a personal computer (hereinafter referred to as “PC”)  210  connected to each other. The portable living body information collector  100  is connected to the PC  210  through a docking station  200 . Connection pins  201 ,  202 , and  203  are provided on the docking station  200 . The connection pins  201 ,  202 , and  203  can be brought into contact with the input/output terminals  110 ,  111 , and  112 , respectively, and are connected to an input/output port of the PC  210  by a cable  204 . Various set data items and inquiry items for detection of living body information can be easily written from the PC  210  to the portable living body information collector  100  by performing communication between the portable living body information collector  100  and the PC  210 . Examples of the set data items are a living body information detection cycle Ts, a detection sensitivity, a questioning cycle Tm, a threshold level C for recognition of change in living body information at which questioning is to be started, and an averaging coefficient N. A threshold value S for skipping of questioning is also set. For questioning, a plurality of questions to be asked may be prepared in advance and a program on the PC may be formed so as to enable selection from the prepared questions, thereby facilitating preparation of a question form. Needless to say, if there is no necessary question in prepared alternatives, a suitable question may be newly made. Conversely, after measurement, living body information obtained by measurement and questioning results are read from the portable living body information collector  100  to the PC  210 . The read living body information and questioning results can be processed on the PC  210 .  
         [0023]    While the docking station  200  and the cable  204  are used for connection between the PC  210  and the portable living body information collector  100  in the described system, a communication means such as an infrared device may be used instead of the docking station and the cable.  
         [0024]    [0024]FIG. 3 is a diagram showing the configuration of the portable living body information collector  100 . A detection circuit  300  detects living body information from a sensor and converts it into an electrical signal. The signal output from the detection circuit  300  is faint and contains a substantial amount of noise. Therefore, amplification and filtering are performed on the signal by a signal processing circuit  301 . The processed signal is quantified by a conversion circuit  302 . The quantification cycle, i.e., the detection cycle is regulated by a control circuit  303  and quantified living body information in each cycle is successively taken into the control circuit. The control circuit  303  records the successively-taken living body information in a storage device  304 . The control circuit  303  also performs questioning in a predetermined cycle. At a time when questioning is to be performed, the control circuit  303  drives a notification means  306  to notify the wearer of a start of questioning and shows on a display device  305  a message for notifying the start of questioning, e.g., “Questioning will be started. Are you ready?”. The wearer inputs, by means of an input device  307 , an answer to the question shown in the display device  305 . The input answer is recorded in the storage device  304  by the control circuit  303 . The living body information and the result of questioning recorded in the storage device  304  are transmitted to an external PC or the like by a communication circuit  308 . The living body information detection cycle and the questioning cycle are also set through the communication circuit  308 .  
         [0025]    [0025]FIG. 4 is a block diagram of this embodiment in a case where bodily movements are detected. An acceleration sensor  400  is a piezoelectric-type acceleration sensor having a piezoelectric element made of lithium niobate, lead ziconate-titanate or the like and formed as a cantilever. The piezoelectric element bends by acceleration to generate electric charge. That is, the acceleration sensor  400  detects acceleration according to a movement of the wearer to output a signal, which is amplified by an amplification means  401 . Since the amplified signal includes noises and high-frequency components, only necessary frequency components are extracted from the signal by a high-pass filter  402  and a low-pass filter  403 . Since the frequency of movements of a human body ranges generally from 0.2 to 9 Hz, the constants of the high-pass filter  402  and the low-pass filter  403  may be selected to extract components in this frequency range. The signal extracted by the high-pass filter  402  and the low-pass filter  403  and representing bodily movements of the wearer is quantified and converted into numeric values by a conversion device  404 . To convert the signal representing bodily movements into a numeric value, a method of direct A/D conversion of the signal or a method of digitizing by comparison with a reference voltage may be used. The latter method is more preferable in terms of reduction in size and in power consumption. In this embodiment, therefore, the conversion means is arranged to digitize the bodily movement signal. A reference voltage used by a comparator  420  is set by signals CS 1  and CS 2  from an I/O port  408 . The comparator  420  compares the reference voltage and the bodily movement signal to convert the bodily movement signal in analog form into a binary digital signal. The digital signal is input to a counter  405  to be obtained as a numeric value. The counter  405 , a timer  406 , a real-time clock (RTC)  407 , the I/O port  408 , an input means  409 , a central processing unit (CPU)  410 , a random-access memory (RAM)  411 , a read-only memory (ROM)  412 , an LCD driver  413 , and a buzzer driver  415  are connected to a bus line. The timer  406  generates interrupt signals in detection cycle Ts and questioning cycle Tm. When an interrupt occurs, the CPU  410  starts processing in accordance with a processing program stored in the ROM  412 . In the case of an interrupt in detection cycle Ts, the value of the counter  405  is recorded by being written to the RAM  411 . That is, time-sequence data on bodily movements in each detection cycle Ts is stored in the RAM  411 . In the case of an interrupt in questioning cycle Tm, the CPU  410  makes the buzzer driver  415  sound a buzzer  416  to notify the wearer of a start of questioning, and also makes the LCD driver  413  successively display on an LCD  414  questions in a question form stored in the RAM  411 . The wearer inputs an answer to each question by using the input means  409 . Input answers are recorded in the RAM  411 . Each time questioning is performed, the CPU  410  reads out time data from the RTC  407  and records it as a questioning execution time in the RAM. The I/O port  408  outputs signals CS 1  and CS 2  and performs communication with an external PC. All of various set values, questions about health, etc., obtained by communication with the PC are stored in the RAM  411 . Conversely, living body information obtained by measurement and questioning results are transmitted to the PC through the I/O port  408 .  
         [0026]    While the buzzer is used as a notification means in the above-described arrangement, any other type of notification means, e.g., vibration, flashing of the display or a notification lamp, or a symbol mark shown on the display for notification may alternatively be used.  
         [0027]    [0027]FIG. 5 shows an example of the bodily movement detection circuit. A piezoelectric-type acceleration sensor  500  is connected in parallel with a resistor  501  and has one electrode grounded and another electrode which is used as an output terminal, and through which a voltage proportional to acceleration is generated. The output terminal is connected to a non-inverting input terminal of an operational amplifier  502 . An inverting input terminal of the operational amplifier  502  is connected to an output terminal of the operational amplifier  502  via a feedback resistor  503  and to the ground via a resistor  504 . These components constitute an amplifier circuit. The output terminal of the operational amplifier  502  is connected to an inverting input terminal of an operational amplifier  510  via capacitors  505  and  507 . An output terminal of the operational amplifier  510 , a feedback resistor  509 , and a capacitor  506  constitute a feedback circuit. A contact point to which the capacitors  505 ,  506 , and  507  are connected is grounded via a resistor  508 . The operational amplifier  510 , the capacitors  505 ,  506 , and  507 , and the resistors  508  and  509  constitute a multi-feedback-type high-pass filter. The output terminal of the operational amplifier  510  is connected to an inverting input terminal of the next operational amplifier  516  via resistors  511  and  513 . An output terminal of the operational amplifier  516 , a feedback resistor  512 , and a capacitor  515  constitute a feedback circuit. A contact point to which the resistors  511 ,  512 , and  513  are connected is grounded via a capacitor  514 . The operational amplifier  516 , the resistors  511 ,  512 , and  513 , and the capacitors  514  and  515  constitute a multi-feedback-type low-pass filter. The output terminal of the operational amplifier  516  is connected to a non-inverting input terminal of a comparator  517 . A reference voltage Vref is applied to an inverting input terminal of the operational amplifier  517  operating as a comparator. The reference voltage Vref is produced by resistors  519 ,  520 ,  521 , and  522  and analog switches  523  and  524 . The analog switches  523  and  524  are turned on and off by signals CS 1  and CS 2 , respectively, to change the value of reference voltage Vref. It is possible to change the sensitivity of the comparator  517  by changing the reference voltage Vref in this manner. An output from the comparator  517  is formed into rectangular waves of unidirectional half-cycles by a buffer  518 . These rectangular waves are input to the counter  405  shown in FIG. 4 to be counted.  
         [0028]    [0028]FIG. 6 shows waveforms at a point AS and an output point PS shown in FIG. 5. Through the point AS, the analog signal representing bodily movements of the wearer is supplied. This signal is compared with the reference voltage Vref by the comparator. The output from the comparator is shaped by the buffer so that the waveform at the point PS is a binary rectangular waveform.  
         [0029]    A procedure for setting of each set value will next be described. FIG. 7 is a flowchart showing a setting procedure. Setting is performed in the state of being connected to a PC as shown in FIG. 2. Set values are determined on the PC and are finally transmitted to the terminal. In step  700 , a living body information detection unit time Ts is set. That is, a minimum unit time during which bodily movements of the wearer are detected is determined. The CPU records the counter value in a cycle of time Ts in the RAM. If the time Ts is set to an excessively small value, a considerably large RAM capacity is required. Conversely, if the time Ts is set to an excessively large value, the counter value is leveled, resulting in failure to detect changes of bodily movements. It is preferable to set the time Ts to 5 to 10 minutes. In step  701 , a detection sensitivity is set. That is, a reference voltage used by the comparator  517  shown in FIG. 5 is set by setting outputs CS 1  and CS 2 . Generally, a person becomes slower in action as he or she ages. If bodily movements are slower, the amplitude of the signal representing the bodily movements is smaller. In such a case, the detection sensitivity is adjusted to a level suitable for detection of the actual signal. In step  702 , questions about health, e.g., “How are you feeling?”, and “Are you irritated?” are set. Needless to say, a plurality of candidate questions to be asked may be prepared in advance and a program on the PC may be formed so as to enable selection from the prepared questions, thereby facilitating question setting. Next, in step  703 , a questioning cycle is set. A time Tm of several hours is set to determine a cycle in which questioning about health is performed. A threshold value C is set separately from the cycle Tm. With this setting, questioning can be started when a change occurs in living body information exceeding the threshold value C. However, there is a possibility of the amount of bodily movement decreasing temporarily due to a comparatively short length of detection unit time Ts. To avoid such an accidental event, an averaging coefficient N is determined. To calculate a change in living body information, the average of the latter half of 2N number of bodily movement data items in time series lately obtained and the average of the former half of the 2N number of data items are compared with each other. Thus, the average values are compared to absorb a temporary change. In step  704 , a threshold value S is set to enable suspension of questioning about health. Questioning during a sleep is avoided by setting the threshold value S. Questioning is normally repeated in the cycle Tm and there is a possibility of arrival of a questioning time in a sleep. However, since bodily movements during a sleep are extremely small, the counter value is compared with the threshold value and a sleeping state of the wearer is recognized to inhibit questioning if the counter value is smaller than the threshold value. The above-described various settings may be made in any order other than the described one. Finally, in step  705 , the set values are transmitted to the portable living body information collector, thereby completing the setting procedure. Thereafter, the wearer fit the portable living body information collector around the wrist and starts measurement by performing a key operation. Questioning about health may be initially performed at the start of measurement.  
         [0030]    [0030]FIGS. 8 and 9 are flowcharts schematically showing the operation of the terminal. When the CPU receives an interrupt, it determines the kind of the interrupt and the process branches according to the result of determination. In this embodiment, a determination is made in step  800  as to whether the interrupt is one in cycle Ts from the timer. In the case of an interrupt in cycle Ts, the process advances to step  801 . In other cases, the process moves to step  900  shown in FIG. 9. In step  801 , the value of the counter is read to the RAM and the counter is reset. The area of the RAM is assumed to be expressed by an array variable V(I). In step  802 , a determination is made as to whether the value V(I) read to the RAM is larger than the threshold value S. If the value V(I) is larger than the threshold value S, it is determined that the wearer is awake, and “0” is written to a flag F in step  803 . If the value V(I) is not larger than the threshold value S, “1” is written to the flag F in step  804  and the process moves to step  809 . In step  805 , a determination is made as to whether the threshold value C has been set. If the threshold value C has been set, the calculation of change in bodily movements is performed in step  806 . If the threshold value C has not been set, the process advances to step  809 . In step  806 , the average in the range from V(I) to V(I−N+1) is represented by X and the average in the range from V(I−N) to V(I−2N+1) is represented by Y. In step  807 , a determination is made as to whether the absolute value of the difference between X and Y is larger than the threshold value C. If the absolute value is larger than the threshold value C, questioning is executed in step  808 . If the absolute value is not larger than the threshold value C, the process moves to step  809 . When the number of counter values recorded in the RAM is smaller than 2N, no average value can be calculated and steps  806 ,  807 , and  808  are not performed (which case is omitted in the flowchart). In step  809 , the parameter I of array V is incremented by 1 to prepare for processing with respect to an interrupt in the next cycle Ts.  
         [0031]    If it is determined in step  800  that the interrupt is not one in cycle Ts, the process moves to step  900  shown in FIG. 9. In step  900 , a determination is made as to whether the interrupt is one in cycle Tm. In the case of an interrupt in cycle Tm, a determination is made in step  901  as to whether the value of the flag F is 0. If F=0, that is, the wearer is awake, then questioning is executed in step  902 . If F≠0, it is determined that the wearer is sleeping and the questioning step is skipped. In the case of a different interrupt, e.g., one by a key operation, it is determined in step  900  that the interrupt is one other than that in cycle Tm, and the process advances to a different interrupt processing step.  
         [0032]    [0032]FIGS. 10A and 10B are diagrams showing examples of graphs obtained by reading measurement results to the PC after the measurement and by drawing by a result analysis function. In the graph of FIG. 10A, the abscissa represents time and the ordinate represents bodily movements, i.e., the counter value. In the graph of FIG. 10B, answers to one question about health are also entered with respect to time. The abscissa represents time on the same scale as that in FIG. 10A and the ordinate represents different feelings. The graphs show that the wearer had an increased amount of activity and a good feeling in a period P 1 , and a reduced amount of activity and a bad feeling in a period P 2 , that the amount of activity was again increased in a period P 3 , and that the wearer was asleep during a period P 4 . Since the counter value during a sleep is smaller than the threshold value S, questioning is skipped during the sleep and no questioning data exists. The wearer woke and became active again in a period P 5 . Thus, according to the present invention, the activity and the mental condition of the wearer can be recorded over a long period of time as the memory allows, and a record obtained in the above-described manner can be used for psychiatric treatment.  
         [0033]    According to the present invention, as described above, information about the living body of a wearer in his or her daily life can be continuously measured in time sequence and the mental condition of the wearer can also be collected in time sequence by asking the wearer some questions. Data obtained in the above-described manner can be used for diagnosis and treatment of melancholy, somnipathy, chronic fatigue syndrome, functional diseases such as irritable bowel syndrome and multiple chemical sensitivity syndrome relating to stress, psychosomatic diseases such as attention deficit hyperactivity disorders, and insanities.
A portable living body information collection device is arranged to continuously measure living body information in daily life and to efficiently collect relating mental information by timely questioning about health. The device can be worn on a human body. The portable living body information collection device extracts living body information in electrical signal form by a detection circuit and a signal processing circuit, and discretizes the information by a conversion circuit. A control circuit stores the discretized living body information in a storage and displays questions about feelings and mental conditions on a display unit periodically or when a large changes occurs in living body information. The wearer inputs answers by using an input device, and the answers are also recorded as mental information in the storage. Write or read of the living body information and mental information recorded in the storage, and various set values to or from an external personal computer can be performed by means of a communication circuit.