Abstract:
A biological sensor device includes a sensor-mounting element worn on part of a user&#39;s face from a front surface to a side surface and further includes a number of biological sensors installed on the sensor-mounting element that measure different types of biological conditions of the user.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS  
       [0001]     The present invention contains subject matter related to Japanese Patent Application JP. 2004-138142 filed in the Japanese Patent Office on May 7, 2004, the entire contents of which are incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to biological sensor devices that acquire biological information by measuring biological conditions of users (conditions of living bodies) and to methods and apparatuses for playing back content, such as images and sound.  
         [0004]     2. Description of the Related Art  
         [0005]     Due to the wide use of wearable computing, a procedure for measuring biological conditions of users using sensors installed on various accessories worn on the bodies of the users and for determining the degrees of fatigue, relaxation, and the like of the users in accordance with results of the measurement has been suggested.  
         [0006]     For example, Japanese Unexamined Patent Application Publication No. 6-51902 discloses an information processing method using a light-emitting element and light-receiving element mounted on eyeglasses worn by an operator of office automation (OA) equipment. In this method, based on the fact that reflected light detected by the light-receiving element is reduced when the operator follows a screen of a display since light from the light-emitting element is projected to the eyes and on the fact that reflected light detected by the light-receiving element increases when the field of view of the operator moves outside the screen of the display since light from the light-emitting element is not incident on the eyes, the degree of fatigue of the operator is estimated. If it is determined that the degree of fatigue increases, a message, such as “Take a little break”, or a desired image is displayed on the screen for the operator.  
         [0007]     In addition, for example, Japanese Unexamined Patent Application Publication No. 10-76012 discloses a relaxation guidance apparatus and a biofeedback guidance apparatus. In paragraph 0140 and FIG. 43 of Japanese Unexamined Patent Application Publication No. 10-76012, a procedure for measuring the pulse rate of a user who receives autogenic training as relaxation training or who receives biofeedback treatment using a pulse wave sensor installed on the frames of eyeglasses worn by the user and for determining whether or not the degree of relaxation of the user is increasing in accordance with the change in measured values over time is described. If the degree of relaxation is increasing, the fact that the degree of relaxation is increasing is informed to the user by projection of light from a liquid crystal panel installed onto the eyeglass frames to the lenses of the glasses.  
       SUMMARY OF THE INVENTION  
       [0008]     In the apparatus and method described in Japanese Unexamined Patent Application Publication No. 6-51902, the field of view (the position of the pupils) of the user is detected using optical sensors, such as a light-emitting element and a light-receiving element. Although the degree of fatigue of the user can be estimated, it is difficult, for example, to estimate and determine the psychological state of a user who views or listens to content, such as images or sound. Thus, it is difficult to use such an apparatus and method in the field of entertainment, such as content playback.  
         [0009]     In addition, in the apparatus and method described in Japanese Unexamined Patent Application Publication No. 10-76012, although the pulse rate of the user. can be measured using the pulse wave sensor, it is difficult, for example, to estimate and determine the psychological state of a user who views or listens to content, such as images or sound. Thus, it is also difficult to use such an apparatus and method in the field of entertainment, such as content playback.  
         [0010]     It is desirable to provide a biological sensor device capable of determining the psychological state of a user who views or listens to content and a content playback method capable of controlling the playback state of the content in accordance with the psychological state of the user who views or listens to the content being played back and capable of playing back content most appropriate for the psychological state of the user.  
         [0011]     According to an embodiment of the present invention, a. biological sensor device includes a sensor-mounting element worn on a portion from a front surface to a side surface of an upper part of a face of a user; and a plurality of biological sensors that is installed on the sensor-mounting element and that measures different types of biological conditions of the user.  
         [0012]     According to an embodiment of the present invention, a content playback method includes the steps of determining a psychological state of a user who views or listens to content by analyzing a plurality of different types of biological information of the user acquired by a plurality of biological sensors installed on a sensor-mounting element worn on a portion from a front surface to a side surface of an upper part of a face of the user; and controlling a playback state of the content in accordance with a result of determination performed in the determination step.  
         [0013]     In the biological sensor device with the foregoing arrangement, a plurality of biological sensors for measuring different types of biological conditions, such as an electromyography sensor and a temperature sensor, a temperature sensor and a vibration sensor, or a vibration sensor and a blood flow sensor, is installed on a sensor-mounting element worn on a portion from the front surface to a side surface of the upper part of the face so as to easily detect various biological conditions of a user. Thus, by analyzing the plurality of different types of biological conditions acquired by the plurality of biological sensors, the psychological state of the user who views or listens to content can be estimated and determined.  
         [0014]     In the content playback method with the foregoing arrangement, the psychological state of a user who views or listens to content can be determined by using the biological sensor device. In accordance with a result of the determination, the playback state of the content, such as the speed of playing back the content, the contrast of a picture, the brightness of the picture, the color of the picture, the rhythm of music, a frequency characteristic of sound, or the volume of the output sound, can be controlled. Thus, the content can be played back most appropriately for the psychological state of the user.  
         [0015]     As described above, a biological sensor device capable of determining the psychological state of a user who views or listens to content is provided. In addition, a content playback method capable of controlling the playback state of the content in accordance with the psychological state of the user who views or listens to the content being played back and capable of playing back content most appropriate for the psychological state of the user is provided. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]      FIG. 1  illustrates a biological sensor device according to an embodiment of the present invention;  
         [0017]      FIG. 2  is a block diagram showing a content playback apparatus according to an embodiment of the present invention;  
         [0018]      FIG. 3  is a flowchart of a playback process performed by a controller of the content playback apparatus;  
         [0019]      FIG. 4  illustrates a content playback system according to a modification of the present invention;  
         [0020]      FIG. 5  illustrates a biological sensor device according to a modification of the present invention; and  
         [0021]      FIG. 6  illustrates a content playback system according to another modification of the present invention.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0022]      FIG. 1  illustrates a biological sensor device  10  according to an embodiment of the present invention. A plurality of biological sensors is installed on a sensor-mounting element having the shape of eyeglass frames.  
         [0023]     More specifically, a sensor-mounting element  11  of the biological sensor device  10  includes a front temple subelement  11   c  and left and right temple subelements  11   a  and  11   b . Electromyography sensors  13  ( 13   a  and  13   b ) are installed on the upper part of the front temple subelement  11   c . Temperature sensors  14  ( 14   a  and  14   b ), a vibration sensor  16 , and an angle sensor  17  are installed at the center of the front temple subelement  11   c . Temperature sensors  15  ( 15   a  and  15   b ) are installed on the left and right temple subelements  11   a  and  11   b , respectively. A blood flow sensor  18  is installed on the leading end of the left temple subelement  11   a , and a pulse wave sensor  19  is installed on the leading end of the right temple subelement  11   b .  
         [0024]     Each of the electromyography sensors  13   a  and  13   b  is a strain sensor or a piezoelectric sensor. The electromyography sensors  13   a  and  13   b  measure the myoelectric potential of the eyebrows. When human beings are happy, the myoelectric potential is low. When human beings are sad, angry, or scared, the myoelectric potential is high. Thus, the countenance of a user whose myoelectric potential is measured can be estimated in accordance with the values measured by the electromyography sensors  13   a  and  13   b.    
         [0025]     The temperature sensors  14   a  and  14   b  measure the temperature of the bridge of the nose of the user. The temperature sensors  15   a  and  15   b  measure the temperature of the temples of the user. When human beings feel uncomfortable, the temperature of the bridge of the nose is low. Thus, a feeling of comfort or discomfort of the user can be estimated in accordance with the difference (absolute value) between the values measured by the temperature sensors  14   a  and  14   b  and the values measured by the temperature sensors  15   a  and  15   b . When the difference is small, it is determined that the user feels comfortable. When the difference is large, it is determined that the user feels uncomfortable.  
         [0026]     The vibration sensor  16  measures the vibration of an area between the eyebrows of the user to detect blinking of the user. The angle sensor  17  detects motion of the whole body of the user or motion of the head of the user to the left and right. When human beings are concentrating on something, the blink rate and the rate of body motion are small. When human beings are not concentrating on something, the blink rate and the rate of body motion are large. Thus, the degree of concentration of the user can be estimated in accordance with the value measured by the vibration sensor  16  or the angle sensor  17 .  
         [0027]     The blood flow sensor  18  measures the volume of blood flow at one ear of the user. The pulse wave sensor  19  measures the pulse rate at the other ear of the user. When human beings feel comfortable, the volume of peripheral blood flow increases and the pulse rate decreases. When human beings feel uncomfortable, the volume of peripheral blood flow decreases and the pulse rate increases. Thus, the feeling of comfort or discomfort of the user can be estimated in accordance with a change in the value measured by the blood flow sensor  18  or the pulse wave sensor  19 .  
         [0028]      FIG. 2  is a block diagram showing a content playback apparatus  20  according to an embodiment of the present invention using the biological sensor device  10  when images and sound are played back as content.  
         [0029]     The content playback apparatus  20  includes a central processing unit (CPU)  21 . A read-only memory (ROM)  23  in which a program performed by the CPU  21 , necessary fixed data, and the like are written, a random-access memory (RAM)  24  into which the program and the data are loaded, a key operation unit  26 , and a liquid crystal display  27  are connected to a bus  22  for the CPU  21 .  
         [0030]     The user who views and listens to the content can select, by a selecting operation using the key operation unit  26 , a playback mode in the content playback apparatus  20  between a playback control mode in which the content playback state is controlled using the biological sensor device  10  and a playback non-control mode in which the content playback state is not controlled and in which the playback state is maintained at a predetermined content playback mode. The liquid crystal display  27  displays operating conditions and the operation state of the content playback apparatus  20 .  
         [0031]     Furthermore, an image display unit  32  is connected to the bus  22  via an image processing unit  31 , and an external output terminal  37  connected to a microphone  35 , a speaker  36 , a headphone, and the like is connected to the bus  22  via a sound processing unit  34 .  
         [0032]     An external storage unit  42 , such as a memory card or an optical disk, is connected to the bus  22  via an interface  41 . A communication cable  45  is connected to the bus  22  via a communication interface  44 . An antenna  48  is connected to the bus  22  via a sending/receiving unit  47 .  
         [0033]     Data of images and sound to be played back is stored in the external storage unit  42 . The data of the images and sound to be played back is captured in the content playback apparatus  20  from an external apparatus via the communication cable  45  or received as broadcast signals by the content playback apparatus  20  via the antenna  48 .  
         [0034]     In this example, the electromyography sensors  13  ( 13   a  and  13   b ), the temperature sensors  14  ( 14   a  and  14   b ), the temperature sensors  15  ( 15   a  and  15   b ), the vibration sensor  16 , the angle sensor  17 , the blood flow sensor  18 , and the pulse wave sensor  19  are connected to the bus  22  via analog-to-digital (A/D) converters  53 ,  54 ,  55 ,  56 ,  57 ,  58 , and  59 , respectively.  
         [0035]     The electromyography sensors  13  are electromyography sensors  13   a  and  13   b . The A/D converters  53  are two A/D converters converting analog signals output from the electromyography sensors  13   a  and  13   b  into digital data. A similar arrangement is applied to the temperature sensors  14  and  15 .  
         [0036]     In this example, when the content playback apparatus  20  plays back an image and sound by reading data of the image and sound recorded in the external storage unit  42 , by capturing data of the image and sound in the content playback apparatus  20  from an external apparatus via the communication cable  45 , or by receiving data of the image and sound as broadcast signals at the content playback apparatus  20  via the antenna  48 , if the playback control mode is set, the CPU  21  analyzes biological information serving as an output of each biological sensor of the biological sensor device  10 , in accordance with a playback processing program described below. The CPU  21  makes a comprehensive evaluation of the analysis results, and determines the psychological state of the user who wears the biological sensor device  10  and who views and listens to the image and sound. The CPU  21  controls the playback state of the image and sound in accordance with the determination result.  
         [0037]     More specifically, as described above, the countenance of the user is estimated in accordance with the result measured by the electromyography sensor  13   a  or  13   b , the feeling of comfort or discomfort of the user is estimated in accordance with the difference between the value measured by the temperature sensor  14   a  or  14   b  and the value measured by the temperature sensor  15   a  or  15   b . Also, the degree of concentration of the user is estimated in accordance with the value measured by the vibration sensor  16  or the angle sensor  17 , and the feeling of comfort or discomfort of the user is estimated in accordance with a change in the value measured by the blood flow sensor  18  or the pulse wave sensor  19 . By comparing these estimation results with predetermined criteria, it is finally determined whether or not the user feels comfortable.  
         [0038]     In brief, when it is estimated that the user is happy, pleasant, and concentrating on something, it is determined that the user feels comfortable. In contrast, when it is estimated that the user is sad, angry, or scared and that the user feels discomfort and is not concentrating on something (inattentive), it is determined that the user feels uncomfortable. For an intermediate case, determination is performed in accordance with the predetermined criteria.  
         [0039]     When it is determined that the user feels comfortable, the image and sound are played back in the current state. When it is determined that the user feels uncomfortable, the playback state of the image and sound is changed in the direction that reduces a stimulus to the user so that the user feels more comfortable.  
         [0040]     More specifically, when it is determined that the user feels uncomfortable, the speed of playing back the image and sound is reduced, the contrast or brightness of a picture is reduced, the hue of the picture is changed to a quiet hue, the color saturation of the picture is reduced, the rhythm of music is reduced, the frequency characteristics of sound, such as music, are increased for the midrange and reduced for the bass and treble ranges, or the volume of the output sound, such as music, is reduced.  
         [0041]      FIG. 3  is a flowchart of a playback process performed by the CPU  21  in the playback control mode. In a playback processing program  60  in this example, the user wears the biological sensor device  10  to start playing back content. In step S 61 , the CPU  21  acquires various types of biological information of the user using the various biological sensors of the biological sensor device  10 . In step S 62 , the CPU  21  analyzes the psychological state of the user in accordance with the various types of acquired biological information. In step S 63 , the CPU  21  determines whether or not the user feels comfortable in accordance with the analysis results.  
         [0042]     If the CPU  21  determines that the user feels comfortable in step S 63 , the process proceeds to step S 64  to play back an image and sound in the current playback state. Then, the process returns to step S 61 . In contrast, if the CPU  21  determines that the user feels uncomfortable in step S 63 , the process proceeds to step S 65  to change the playback state of the image and sound as described above. Then, the process returns to step S 61 .  
         [0043]     By repeating this process, the user can view images and listen to sounds in a state in which the user feels comfortable.  
         [0044]     As shown in  FIG. 4 , a content playback system may include an image and sound playback apparatus  75  and a head-mount display  71  used for viewing images and listening to sounds played back by the sound playback apparatus  75 . In this case, various biological sensors may be installed on the head-mount display  71  so as to use the head-mount display  71  as a biological sensor device. With this arrangement, the user need not wear the biological sensor device  10  shown in  FIG. 1 , independent of the head-mount display  71 .  
         [0045]     As shown in  FIG. 5 , a head-band biological sensor device  81  on which various biological sensors are installed, instead of a biological sensor device having the shape of eyeglass frames, may be used.  
         [0046]     In addition, as shown in  FIG. 6 , a content playback system may include the biological sensor device  10 , an image playback apparatus  91  including a remote-control transmitter  93 , and a sound playback apparatus  95 . In this case, the biological sensor device  10 , the image playback apparatus  91 , and the sound playback apparatus  95  may be connected to each other using cables  92  and  96  or radio communication.  
         [0047]     Although a case where images and sound are played back as content has been described, the present invention is not necessarily limited to this. The present invention is also applicable to a case were only information that can be visually sensed, such as images (pictures), is played back or a case where only information that can be acoustically sensed, such as sound (music), is played back.  
         [0048]     In addition, biological sensors that are installed on a sensor-mounting element and that measure biological conditions of human beings are not necessarily limited to an electromyography sensor, a temperature sensor, a vibration sensor for measuring blinking, an angle sensor for measuring body motion, a blood flow sensor, and a pulse wave sensor. Sensors for measuring skin perspiration, skin resistance, and microvibration (MV) may be used, as long as they can measure biological conditions of human beings at a portion from the front surface to a side surface of the upper part of the face.  
         [0049]     It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.