Patent Publication Number: US-2021161416-A1

Title: Biometric data measurement system and information processing device

Description:
TECHNICAL FIELD 
     The present invention relates to a biometric data measurement system and an information processing device. 
     BACKGROUND ART 
     In recent years, devices measuring various biometric data such as blood pressure, electrocardiographic data, and the like have been used at home. One such biometric data measurement device is an electronic blood pressure monitor. A common electronic blood pressure monitor includes a cuff wrapped around the upper arm or the wrist, and a body connected with the cuff integrally or via a tube. The following are disposed in the body: a mechanical structure including a pump for feeding a fluid (typically air) to a fluid bag provided in the cuff, a pressure sensor for detecting a pressure change in the fluid, and the like, and an electrical circuit controlling a pump and the like, calculating a blood pressure value based on a pressure sensor output. A body surface is provided with user interfaces including an operation member for instructing operation of an electronic blood pressure monitor and a display unit for displaying the calculated blood pressure value. 
     On the other hand, as in Patent Documents 1 and 2, a biometric data measurement system has been proposed in which the main user interfaces such as the operation member and the display unit are omitted from the body, or which includes a minimum necessary user interface mounted on the body and utilizes a user interface provided as an application program for an information processing device such as a smartphone. 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Document 1: JP 6251239 B 
         Patent Document 2: US 2014/0,159,912 A 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     The information processing device can execute various application programs, and some of the application programs, for example, messaging application programs, are constantly executed in the background. For example, when a message is received, a messaging application program emits a ringtone or a ringer melody through a speaker, changes a pictogram on an upper part of a display screen, or displays a message content in a pop-up window on the display screen. 
     Thus, even in a biometric data measurement system in which the user interface is an information processing device, as disclosed in Patent Documents 1 and 2, some application programs are executed in the background even during measurement of biometric data such as the blood pressure. Thus, depending on the content displayed on the display screen of the information processing device by the application program during measurement of biometric data, the mental state may change to deteriorate the resting state, affecting the biometric data such that, for example, the blood pressure increases. This may prevent accurate biometric data measurement. 
     In light of the above-described circumstances, and an object of the present invention is to provide a biometric data measurement system and the information processing device that can perform accurate biometric data measurement utilizing an information processing device as a user interface. 
     Solution to Problem 
     The present invention adopts the following configurations in order to achieve the above-mentioned object. 
     In one aspect of the invention, a biometric data measurement system includes: 
     a biometric data measurement device configured to measure biometric data of a subject; and
 
an information processing device configured to control a biometric data measurement operation by the biometric data measurement device, wherein
 
the information processing device includes:
 
a communication unit configured to connect to a communication network;
 
a display unit including a display screen displaying various pieces of information;
 
a connection unit configured to connect to the biometric data measurement device wirelessly or by wire;
 
an operation unit configured to receive a start operation for a measurement operation for biometric data of the subject by the biometric data measurement device; and
 
a control unit configured to transmit a measurement start command for starting measurement of the biometric data, to the biometric data measurement device via the connection unit when a measurement start condition is satisfied after the operation section receives the start operation, and
 
the measurement start condition includes prevention of the subject from viewing a display content of the display screen. Note that when the measurement start condition is satisfied, the control unit may further erase a display screen of the display unit. According to this configuration, the biometric data measurement is started under a condition that the subject is prevented from viewing the display content of the display screen. Thus, regardless of whatever content is displayed by the application program executed by the information processing device in the background during the biometric data measurement, the subject is prevented from viewing the content, preventing the biometric data measurement from being affected. Consequently, even in a case where the information processing device is used as a user interface, accurate biometric data measurement can be performed. When the measurement start condition is satisfied, erasing the display screen of the display unit enables suppression of power consumption of the information processing device.
 
     In one aspect of the invention, the information processing device may further include a sensor configured to detect an angle of the display screen with respect to a gravitational direction, and the control unit may include a determination unit configured to determine that the measurement start condition is satisfied when the angle of the display screen equals a measurement start angle at which the subject is prevented from viewing the display screen. For example, a sensor such as an acceleration sensor or a gyroscopic sensor can be used to detect the angle of the display screen, that is, the direction in which the display screen faces. The determination unit may determine that the measurement start condition is satisfied, for example, when the display screen is oriented approximately in the ground direction, that is, when the information processing device is laid face down on a desk or the like. The start operation of the subject acting as an operator operating the information processing device can be performed, for example, by touching an icon or button image on the display screen, and of course, the subject needs to be able to view the display screen. In a case where the subject performs the start operation with the information processing device in hand rather than with the information processing device placed on a desk or the like, the display screen generally substantially directly faces the face of the subject. Thus, the measurement start angle can be an angle greater than ±90 degrees with respect to the angle of the display screen of the display unit when the subject receives the start operation. 
     According to this configuration, the use of the angle of the display screen as an indicator allows the subject as the operator to be easily determined to be prevented from viewing the display content of the display screen. 
     In the aspect described above, the information processing device may further include a sensor configured to detect that the display screen is covered, and the control unit may include a determination unit configured to determine that the measurement start condition is satisfied when the display screen is covered. For example, in a case where the information processing apparatus is in a notebook type cover, closing the cover covers the display screen to allow no one to view the display screen. When the information processing device is laid face down on a desk or the like, the display screen is covered by a top plate of the desk. For example, the illuminance of the display screen can be detected by a sensor such as a front camera (sub-camera) or an illuminance sensor provided on the same surface as the surface on which the display screen of the information processing device is disposed. The determination unit can determine whether the display screen is covered based on the illuminance detected by the sensor. According to this configuration, by using, as an indicator, whether the display screen is covered, the subject can be easily determined to be prevented from viewing the display content of the display screen. 
     In the aspect described above, the information processing device may further include a sensor configured to detect a line of sight of an operator operating the operation unit, and the control unit may include a determination unit configured to determine that the measurement start condition is satisfied when the line of sight of the operator is away from the display screen. When the subject acting as an operator operating the information processing device performs the start operation, the subject naturally views the display screen. Thus, for example, in a case where the line of sight of the subject is detected by a known line-of-sight detection technique utilizing a sensor such as a front camera (sub-camera) provided on the same surface as the surface on which the display screen of the information processing device is placed and where the detected line of sight is away from the display screen, the subject can be determined to be prevented from viewing the display content of the display screen. Thus, the determination unit can determine whether the line of sight of the subject is away from the display screen based on an image captured by a sensor such as a front camera. According to this configuration, by using, as an indicator, whether the line of sight of the subject is away from the display screen, the subject can be easily determined to be prevented from viewing the display content of the display screen. 
     In the aspect described above, the information processing device may further include a sensor configured to detect that the biometric data measurement device is present opposite to the display screen with respect to the information processing device, and the information processing device may include a determination unit configured to determine, when the operation unit receives the start that the measurement start condition is satisfied in a case where the biometric data measurement device is present opposite to the display screen with respect to the information processing device. In a case where the operator operating the information processing device is different from the subject of the biometric data, the positional relationship between the subject and the information processing device varies, and it is difficult to determine which orientation of the display screen prevents the subject from viewing the display content of the display screen. However, in a case where the biometric data measurement device is present opposite to the display screen when the start operation is performed, the subject wearing the biometric data measurement device is reliably opposite to the display screen. Thus, this can be used as an indicator. For example, in a case where a sensor such as a rear camera (main camera) typically provided in the information processing device is utilized to extract, from an image, a logo of the product name of the biometric data measurement device, a model number, or the like and where the logo or the model number corresponds to a particular or preset biometric data measurement device, the determination unit can determine that the biometric data measurement device is present opposite to the display screen. According to this configuration, whether a biometric data measurement device is present opposite to the display screen or not is used as an indicator. This allows the subject to be easily determined to be prevented from viewing the display content of the display screen. 
     In the aspect described above, the control unit may control the display unit such that when the operation unit receives the start the display unit changes display on the display screen to a display state in which the subject is prevented from viewing the display, and the control unit may include a determination unit configured to determine that the measurement start condition is satisfied when the display content of the display screen changes to the display state in which the subject is prevented from viewing the display content. For example, the control unit forcibly dims the display screen, preventing the subject from viewing the display content of the display screen. However, sudden erasure of the display screen may be mistaken for a failure or may surprise the subject, adversely affecting the biometric data measurement. Thus, the display on the display screen is desirably gradually dimmed. Alternatively, the control unit may forcibly activate a screen saver. 
     According to this configuration, by using, as an indicator, whether the display on the display screen has changed to a state in which the subject is prevented from viewing the display content, the subject can be easily determined to be prevented from viewing the display content of the display screen. 
     In the aspect described above, desirably, the information processing device further includes a notification unit including at least one of a speaker configured to generate sound and a vibration member configured to generate vibration, and the control unit causes, after elapse of a certain period of time since satisfaction of the measurement start condition, the notification unit to notify the subject of start of measurement, and the control unit transmits, after notification of the start of measurement by the notification unit, the measurement start command to the biometric data measurement device via the connection unit. 
     According to this configuration, when the measurement start condition is satisfied, after the elapse of a certain period of time since the satisfaction, the start of measurement is notified and then the measurement is started. Thus, as is the case with a typical biometric data measurement device, the subject can behave from sensing of the start of measurement. Because the notification is provided in a case where the subject is prevented from viewing the display content of the display screen, the notification of the start of measurement is provided by sound or vibration rather than being displayed on the display screen. 
     In the aspect described above, the control unit may prohibit operation of the notification unit during measurement of the biometric data by the biometric data measurement device, and when a measurement result for the biometric data is received from the biometric data measurement device via the connection unit, the control unit may cause the notification unit to notify the subject of end of the measurement. According to this configuration, during the biometric data measurement, sound or vibration that inhibits the resting state of the subject, such as a reception ringtone or alert vibration is prevented from being produced during message reception. This enables a further reduction in the adverse effect of the operation of another application program. When the measurement result is received from the biometric data measurement device, the end of measurement is notified by sound or vibration, and thus the end of the biometric data measurement can be reliably notified to the subject. 
     In the aspect described above, the control unit may include an operation guidance unit configured to display a guidance message prompting movement of the information processing device to satisfy the measurement start condition, on the display screen when the operation unit receives the start operation. 
     According to this configuration, by displaying and/or audibly outputting, during the start operation, the guidance message prompting movement of the information processing device to satisfy the measurement start condition, how to actually start the measurement can be indicated to the subject. Furthermore, the guidance message may be audibly output. 
     In the aspect described above, the control unit may include a notification unit configured to display a message promoting biometric data measurement with the biometric data measurement device, on the display screen at a preset date and time, and the control unit may gradually dim the display on the display screen after the notification unit outputs the message. Note that, when the control unit gradually dims display in such manner, in a case where the control unit is connected to the biometric data measurement device within a certain period of time, the control unit preferably recovers the display on the display screen to an original state and then starts to determine whether the measurement start condition is satisfied. Furthermore, the message prompting the biometric data measurement with the biometric data measurement device may be audibly output. 
     According to this configuration, at or near the date and time of start of the measurement, the message prompting the biometric data measurement with the biometric data measurement device is displayed and/or audibly output. Thus, the subject can be prompted to measure the biometric data at a preset date and time and prevented from forgetting the measurement. Moreover, when the display is gradually dimmed after the message prompting the biometric data measurement is output, even in a case where the subject is operating any other application program on the information processing device, the operation is made difficult, allowing the subject to be diverted to the biometric data measurement. 
     In the aspect described above, the biometric data measurement device can include a blood pressure monitor that includes: a blood pressure measurement unit including a cuff containing a fluid bag and wrapped around a measured site of the subject and configured to measure a blood pressure of the subject; a detection unit configured to detect a state of wrapping, around the measured site, of the cuff of the blood pressure measurement unit; a blood pressure monitor connection unit connected wirelessly or by wire to the information processing device, and a blood pressure monitor control unit configured to cause the blood pressure measurement unit to measure the blood pressure of the subject when the measurement start command is received from the information processing device via the blood pressure monitor connection unit, and transmit a result of the measurement to the information processing device via the blood pressure monitor connection unit. 
     According to this configuration, the blood pressure monitor, corresponding to the biometric data measurement device, can start measurement of the blood pressure in response to the operation of the information processing device by the subject, allowing the operation unit to be omitted from the blood pressure monitor. Furthermore, the blood pressure measurement result from the blood pressure monitor can be transmitted to the information processing device and displayed on the information processing device side, allowing the display unit to be omitted from the blood pressure monitor. 
     Here, the control unit may include an inquiry unit configured to inquire of the blood pressure monitor, via the connection unit, whether or not preparation for measurement with the blood pressure measurement unit is completed, and when the inquiry is received from the information processing device, the blood pressure monitor control unit may transmit a measurement preparation completion notification to the information processing device via the blood pressure monitor connection unit in a case where a state of wrapping of the cuff around the measured site detected by the detection unit corresponds to a blood pressure measurement enabled state, and when the measurement preparation completion notification is received, the control unit may start determining whether the measurement start condition is satisfied. 
     According to this configuration, in response to the start operation, whether the blood pressure monitor is ready is checked before determination of whether the measurement start condition is satisfied is started. This allows prevention of possible start of blood pressure measurement before a state required for measurement of the blood pressure of the subject is established. Thus, even in a case where the operation member is separate from the blood pressure monitor, the measurement can be made reliable, while the safety of the measurement can be ensured. 
     When the measurement start condition is no longer satisfied after the measurement start command is transmitted to the blood pressure monitor, the control unit may transmit a measurement stop command to the blood pressure monitor via the connection unit, and when the blood pressure monitor control unit receives the measurement stop command from the information processing device, in a case where a compressed state by the fluid bag contained in the cuff of the blood pressure measurement unit continues for a certain period of time or longer, the blood pressure monitor control unit may discontinue the measurement of the blood pressure and causes a fluid in the fluid bag to be discharged. For example, in the sense of a switch for emergency discharge (stop) in preparation for a case where an abnormality occurs in a fluid feeding mechanism of the blood pressure monitor and the compressed state by the fluid bag continues, “in a case where the compressed state continues for longer than a certain period of time and the information processing device in, for example, a face-down state is suddenly moved,” processing for emergency stop can be executed. According to this configuration, when the measurement start condition is no longer satisfied, the blood pressure measurement is discontinued and the fluid in the fluid bag is discharged in a case where the compressed state by the fluid bag of the cuff continues for a certain period of time or longer. Thus, even in a case where the operation member is separate from the blood pressure monitor, the safety can be ensured. 
     The blood pressure monitor may further include an emergency stop button dedicated to emergency stop or also used as another button, and in response to an operation of the emergency stop button, the blood pressure monitor control unit may discontinue the measurement of the blood pressure and cause the fluid in the fluid bag contained in the cuff of the blood pressure measurement unit to be discharged. According to this configuration, the blood pressure monitor discontinues the blood pressure measurement and causes the fluid in the fluid bag to be discharged in response to an operation of the emergency stop button provided in the blood pressure monitor, and thus the safety of the measurement can be ensured. 
     In another aspect of the present invention, an information processing device includes 
     a communication unit configured to connect to a communication network;
 
a display unit including a display screen displaying various pieces of information;
 
a connection unit configured to connect to another device wirelessly or by wire;
 
an operation unit configured to receive a user operation; and
 
a control unit configured to control each of the units, wherein the control unit
 
determines whether a measurement start condition is satisfied when the operation unit receives a measurement start operation for a biometric data measuring device measuring biometric data of a subject, and
 
transmits a measurement start command to the biometric data measurement device via the connection unit in a case where the measurement start condition is satisfied, and the measurement start condition includes prevention of the subject from viewing a display content of the display screen. Note that when the measurement start condition is satisfied, the control unit may further erase a display screen of the display unit.
 
     According to this configuration, the information processing device instructs the biometric data measurement device to start biometric data measurement provided that the subject is prevented from viewing the display content of the display screen. Thus, regardless of whatever content is displayed by the application program executed by the information processing device in the background during the biometric data measurement, the subject is prevented from viewing the content, preventing the biometric data measurement by the biometric data measurement device from being affected. Consequently, even in a case where the information processing device is used as a user interface, accurate biometric data measurement can be performed. When the measurement start condition is satisfied, the display screen of the display unit is further erased, enabling power consumption of the information processing device to be suppressed. 
     In another aspect of the present invention, a method for causing a biometric data measurement device to measure biometric data is a method for causing a biometric data measurement device to measure biometric data, the method being executed by an information processing device including a processor, a memory, a communication unit connecting to a communication network, a display unit including a display screen displaying various pieces of information, a connection unit connecting to another device wirelessly or by wire, and an operation unit receiving a user operation, the method including the steps of: 
     the processor determining whether a measurement start condition is satisfied when the operation unit receives a measurement start operation for the biometric data measuring device, and
 
the processor transmitting a measurement start command to the biometric data measurement device via the connection unit in a case where the measurement start condition is satisfied,
 
wherein the measurement start condition includes prevention of the subject of the biometric data from viewing a display content of the display screen.
 
     According to this configuration, the information processing device instructs the biometric data measurement device to start biometric data measurement on condition that the subject is prevented from viewing the display content of the display screen. Thus, regardless of whatever content is displayed by the application program executed by the information processing device in the background during the biometric data measurement, the subject is prevented from viewing the content, preventing the biometric data measurement by the biometric data measurement device from being affected. Consequently, even in a case where the information processing device is used as a user interface, accurate biometric data measurement can be performed. 
     In another aspect of the invention, a biometric data measurement program may be a program causing a processor to function as the control unit included in the information processing device according to the aspect described above or another aspect. 
     According to this configuration, the information processing device including the processor executing the biometric data measurement program instructs the biometric data measurement device to start biometric data measurement on condition that the subject is prevented from viewing the display content of the display screen. Thus, regardless of whatever content is displayed by the application program executed by the information processing device in the background during the biometric data measurement, the subject is prevented from viewing the content, preventing the biometric data measurement by the biometric data measurement device from being affected. Consequently, even in a case where the information processing device is used as a user interface, accurate biometric data measurement can be performed. 
     Advantageous Effects of Invention 
     According to the present invention, a technique can be provided that allows accurate biometric data measurement to be performed even in a case where an information processing device is used as a user interface. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram schematically illustrating an example of a biometric data management system according to an embodiment. 
         FIG. 2  is a block diagram schematically illustrating an example of a configuration of a blood pressure monitor and an information processing device in a biometric data measurement system according to the embodiment. 
         FIG. 3  is a block diagram illustrating an example of a configuration of a blood pressure monitor in a biometric data measurement system according to a first embodiment. 
         FIG. 4  is a block diagram illustrating an example of a configuration of an information processing device in the biometric data measurement system according to the first embodiment. 
         FIG. 5  is a flowchart illustrating an example of a processing procedure of the information processing device in accordance with a blood pressure measurement application program. 
         FIG. 6A  illustrates a first portion of the flowchart illustrating an example of a processing procedure for a blood pressure monitor. 
         FIG. 6B  illustrates a second portion of the flowchart illustrating an example of the processing procedure for the blood pressure monitor. 
         FIG. 7  is a flowchart illustrating an example of a processing procedure of measurement start determination processing in  FIG. 5 . 
         FIG. 8  is a flowchart illustrating an example of a processing procedure of measurement start determination processing in a first modified example of the first embodiment. 
         FIG. 9  is a flowchart illustrating an example of a processing procedure of measurement start determination processing in a second modified example of the first embodiment. 
         FIG. 10  is a flowchart illustrating an example of a processing procedure of measurement start determination processing in a third modified example of the first embodiment. 
         FIG. 11A  is a flowchart illustrating an example of a processing procedure of measurement start determination processing in a fourth modified example of the first embodiment. 
         FIG. 11B  is a flowchart illustrating another example of the processing procedure of measurement start determination processing in the fourth modified example of the first embodiment. 
         FIG. 12  is a flowchart illustrating an example of a processing procedure for an information processing device in accordance with a blood pressure measurement application program in a biometric data measurement system according to a second embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiments of the present invention will be described below based on the drawings. 
     Here, as an example, a case will be described in which a biometric data measurement device is an electronic blood pressure monitor that uses a technique (oscillometric method) for compressing the blood vessel to detect a pulse wave. 
     Application Example 
     First, with reference to  FIGS. 1 and 2 , an example of a case in which the present invention is applied will be described.  FIG. 1  schematically illustrates an example of a biometric data measurement system  1  according to an embodiment.  FIG. 2  schematically illustrates an example of the configuration of the biometric data measurement system  1 . 
     Configuration of Application Example 
     In the example in  FIGS. 1 and 2 , the biometric data measurement system  1  includes a blood pressure monitor  2  that measures the blood pressure of a subject, and an information processing device  3  that controls a blood pressure measurement operation by the blood pressure monitor  2 . 
     The blood pressure monitor  2  is, for example, an electronic blood pressure monitor including a blood pressure monitor body  21  and a cuff  22  wrapped around a measured site of a subject, such as the upper arm or wrist of the subject. 
     The cuff  22  is a part of the blood pressure measurement unit  23  that measures the blood pressure of the subject and contains, for example, a fluid bag  24 . Other portions of the blood pressure measurement unit  23  are configured in the blood pressure monitor body  21 . The blood pressure measurement unit  23  may include, in the blood pressure monitor body  21 , for example, a piezoelectric pump, a pressure sensor, a valve, or the like. 
     In addition to a part of the blood pressure measurement unit  23 , the blood pressure monitor body  21  includes, for example, a detection unit  25 , a blood pressure monitor connection unit  26 , and a blood pressure monitor control unit  27 . Although not illustrated, the blood pressure monitor body  21  includes, for example, a battery and a power button. The blood pressure monitor body  21  may further include an emergency stop button  28 , for example. 
     The detection unit  25  detects a state of wrapping of the cuff  22  around the upper arm, wrist, or the like, corresponding to the measured site of the subject. The detection unit  25  may detect the state of wrapping of the cuff  22  by detecting, for example, a state of electrical connection of an electrical contact provided in the cuff  22 , marks aligned along the longitudinal direction of the cuff  22  and optically detected, a wrapping shape of the cuff  22  detected by a shape sensor such as a fiber sensor inserted through the cuff  22  in the longitudinal direction, and the like. 
     The blood pressure monitor connection unit  26  is a communication interface that connects to the information processing device  3  wirelessly or by wire and transmits and receives information to and from the information processing device  3 . The blood pressure monitor connection unit  26  may be, for example, a near field wireless communication interface. The near field wireless communication interface may be, but is not limited to, a BLE communication module employing near field wireless data communication standards such as, for example, Bluetooth (trade name). The blood pressure monitor connection unit  26  may be a wired communication interface such as a Universal Serial Bus (USB) interface that communicates via a Universal Serial Bus (USB) cable. 
     Although not illustrated, the blood pressure monitor control unit  27  includes, for example, a processor such as a central processing unit (CPU) or a micro processing unit (MPU) and a memory such as a random access memory (RAM), a read only memory (ROM), and the like, and controls components of the blood pressure monitor  2  according to information processing. The ROM stores, for example, programs to be executed by the processor. The RAM is, for example, a memory used as a work memory by the processor. By executing the programs required by the processor, the blood pressure monitor control unit  27  can perform various operations. 
     The emergency stop button  28  is a button for instructing the blood pressure monitor control unit  27  to stop the operation of the blood pressure monitor  2 , for example. Note that the emergency stop button  28  is not limited to a dedicated button, and may also be used as another button such as a power button. For example, in a case where the emergency stop button is also used as another button, the usage is assumed in which, for example, power on/off is instructed by long depression, whereas emergency stop is instructed by short depression. 
     The information processing device  3  may be a smart device such as a typical smartphone or a tablet terminal. The information processing device  3  includes, for example, a communication unit  31 , a connection unit  32 , an operation unit  33  including an operation button  33 A, a display unit  34 , a sensor  35 , a notification unit  36 , and a control unit  37 . 
     The communication unit  31  may include, for example, a Wi-Fi (trade name) module. The communication unit  31  is, for example, connected to a communication network NW such as the Internet or a telephone network via a Wi-Fi base station not illustrated, and communicates with an external device via the communication network NW. 
     The connection unit  32  is a communication interface that connects wirelessly or by wire to the blood pressure monitor connection unit  26  of the blood pressure monitor  2  and that transmits and receives information to and from the blood pressure monitor  2 . The connection unit  32  may be, for example, a near field wireless communication interface. The near field wireless communication interface may be, but is not limited to, a BLE communication module employing near field wireless data communication standards such as, for example, Bluetooth (trade name). The connection unit  32  may be a wired communication interface, for example, a USB interface that communicates via a USB cable. 
     The operation unit  33  includes various operation buttons, for example, an operation button  33 A provided on a front surface of the information processing device  3  and an operation button (not illustrated) provided on a side surface of the information processing device  3 . The operation unit  33  includes a touch panel disposed on a display screen of the display unit  34 , for example. 
     The display unit  34  includes a display screen  38  that displays various pieces of information including information related to measurement, for example. The information related to measurement may include, for example, a measurement start guidance message, an error message, a measurement result, and the like. The display screen  38  may be, for example, a liquid crystal display or an organic electroluminescent display. 
     The sensor  35  may include, for example, a sensor that detects the angle of the display screen  38  with respect to the gravitational direction, a sensor that detects that the display screen  38  is covered, a sensor that detects that the line of sight of an operator operating the operation unit is away from the display screen  38 , a sensor detecting that the blood pressure monitor  2  is present opposite to the display screen  38 , and the like. 
     The sensor that detects the angle of the display screen  38  with respect to the gravitational direction includes, for example, an acceleration sensor and a gyroscopic sensor. The acceleration sensor detects, for example, the acceleration of the information processing device  3 . The acceleration sensor is not limited to detection of the accelerations in the directions of the X, Y, and Z axes, for example, and may detect the acceleration in the rotational direction around each axis. The gyroscopic sensor detects the angle of rotation in a case where the information processing device  3  rotates around each of the X, Y, and Z axes. 
     The sensor that detects that the display screen  38  is covered includes, for example, a front camera  35 A and an illuminance sensor  35 B provided on the same face as a surface on which the display screen  38  of the information processing device  3  is disposed (hereinafter, referred to as the front surface). The front camera  35 A is, for example, a camera disposed in proximity to the display screen  38  on the front surface of the information processing device  3 , and can capture an image of, for example, the face of the operator operating the information processing device  3 . The illuminance sensor  35 B is disposed, for example, on the front surface of the information processing device  3  in proximity to the display screen  38 , and detects the illuminance on the display screen  38 . 
     The sensor detecting that the line of sight of the operator operating the operation unit  33  is away from the display screen  38  can include, for example, the front camera  35 A. 
     The sensor detecting that the blood pressure monitor  2  is present opposite to the display screen  38  includes, for example, a rear camera disposed on a surface of the information processing device  3  opposite to the front surface of the information processing device  3  (hereinafter referred to as the rear face). Typically, the rear camera used provides a higher definition and higher functions than the front camera  35 A. Thus, the rear camera is also referred to as a main camera, and the front camera  35 A may be referred to as a sub-camera. 
     The notification unit  36  may include a speaker  39  and a vibration member  40 . The speaker  39  produces sound and, together with a microphone not illustrated, functions as a user interface for a phone call. In addition to telephone voice, the speaker  39  can output various sounds, such as ringtones for telephone, email, messages, and music. The vibration member  40  is, for example, a vibrator that vibrates the information processing device  3 , for example, when a telephone call, an email, a message, or the like is received. The vibration member  40  may be used, for example, in order to provide a realistic sensation during the execution of a game application program in the information processing device  3 . 
     Although not illustrated in the drawings, the control unit  37  includes a processor such as a CPU or an MPU and a memory such as a RAM and a ROM, for example, and controls the components of the information processing device  3  in accordance with information processing. The ROM stores, for example, programs to be executed by the processor. The RAM is, for example, a memory used as a work memory by the processor. With the processor executing the required program, the control unit  37  can perform various operations. 
     The control unit  37  can perform functions of, for example, a determination unit  41 , an operation guidance unit  42 , a notification unit  43 , and an inquiry unit  44 . The determination unit  41  determines, for example, whether a start condition for blood pressure measurement performed by the blood pressure monitor  2  is satisfied or not. For example, when the operation unit  33  receives the start operation, the operation guidance unit  42  displays, on the display screen  38 , a guidance message prompting movement of information processing device  3  to satisfy the measurement start condition. The notification unit  43 , for example, displays a message prompting blood pressure measurement with the blood pressure monitor  2 , on the display screen  38  at a preset date and time. The inquiry unit  44 , for example, inquiries of the blood pressure monitor  2  via the connection unit  32 , whether measurement preparation for the blood pressure measurement unit  23  is complete. 
     Operation of Application Example 
     Now, an example of the operation of the biometric data measurement system  1  will be described. 
     In a case where the subject measures the blood pressure, the wrist is passed through the cuff  22 , as indicated by arrow A in  FIG. 1 , with the palm of the subject facing upward, to attach the blood pressure monitor  2  to the wrist. Before or after this attachment operation, an operator who is a subject operates a power switch (not illustrated) of the blood pressure monitor  2 , for example, to make the blood pressure monitor  2  operable. The subject activates the blood pressure measurement application program of the pre-paired information processing device  3 , for example. Thus, an operation is performed that establishes communication between the blood pressure monitor connection unit  26  of the blood pressure monitor  2  and the connection unit  32  of the information processing device  3 . When the blood pressure measurement application program of the information processing device  3  is activated, the control unit  37  of the information processing device  3 , for example, causes the display screen  38  of the display unit  34  to display an icon  38 A for instructing the start of blood pressure measurement. 
     In such a situation, when the operator corresponding to the subject touches the icon  38 A, a touch sensor  33 B at the touch position is turned on on a touch panel on the display screen  38  included in the operation unit  33  of the information processing device  3 . The operation unit  33  outputs coordinate data indicating the touch position to the control unit  37 , for example. The control unit  37  can determine, for example, from the display content of the display screen  38  at the touch position, that a start operation has been performed that starts a blood pressure measurement operation by the blood pressure monitor  2 . In this way, the operation unit  33  receives the start operation for the blood pressure measurement operation by the blood pressure monitor  2 . 
     After receiving the start operation from the operation unit  33 , the control unit  37 , for example, causes the determination unit  41  to determine whether a measurement start condition is satisfied. The measurement start condition includes, for example, prevention of the subject from viewing the display content of the display screen  38  of the display unit  34 . Then, when the measurement start condition is satisfied, the control unit  37 , for example, causes the connection unit  32  to transmit a measurement start command to the blood pressure monitor  2 . The control unit  37  may, for example, further erases the display screen  38  of the display unit  34  when the measurement start condition is satisfied. Erasing the display screen  38  allows power consumption of the information processing device  3  to be suppressed. 
     For example, after communication is established between the blood pressure monitor connection unit  26  and the connection unit  32  of the information processing device  3 , or after connection is complete, the blood pressure monitor  2  waits to receive the measurement start command from the information processing device  3 . When the measurement start command is received from the information processing device  3  through the blood pressure monitor connection unit  26 , the blood pressure monitor control unit  27 , for example, causes the blood pressure measurement unit  23  to measure the blood pressure of the subject, and transmits a measurement result to the information processing device  3  through the blood pressure monitor connection unit  26 . 
     For example, after causing the connection unit  32  to transmit the measurement start command to the blood pressure monitor  2 , the information processing device  3  waits to receive the measurement result from the blood pressure monitor  2 . When the information processing device  3  receives a measurement result from the blood pressure monitor  2  through the connection unit  32 , the control unit  37 , for example, displays the received measurement result on the display screen  38  of the display unit  34 . The control unit  37  can cause, for example, the communication unit  31  to transmit the received measurement result to an external device, for example, an information terminal of a physician or a server device via the communication network NW. 
     In this way, the control unit  37  of the information processing device  3  can cause the blood pressure measurement with the blood pressure monitor  2  to be started, for example, on condition that the subject is prevented from viewing the display content of the display screen  38 . Thus, regardless of whatever content is caused to be displayed on the display screen by an application program executed by the information processing device  3  in the background during the blood pressure measurement, the subject is prevented from viewing the content, thus preventing the blood pressure measurement from being affected. Accordingly, even in a case where the information processing device  3  is used as a user interface for the blood pressure monitor  2 , accurate blood pressure measurement can be performed. 
     Note that during measurement by the blood pressure monitor  2 , for example, the control unit  37  prohibits the operation of the speaker  39  and the vibration member  40  included in the notification unit  36 , and performs control to prevent possible sound or vibration that inhibits the resting state of the subject, such as a reception ringtone or alert vibration during message reception. Thus, even with an incoming email or message, not only is the display invisible but also no ringtone or vibration is produced, enabling a further reduction in the adverse effect of operation of another application program such as an email application program or a messaging application program. Furthermore, the control unit  37  may, for example, perform control to put on, through the speaker  39 , music or the like that assists in maintaining the resting state of the subject during the blood pressure measurement. 
     Instead of immediately prohibiting the operation of the speaker  39  and the vibration member  40  of the notification unit  36  when the measurement start condition is satisfied, the notification unit  36  may produce a ringtone or alert vibration that notifies the start of measurement a certain period of time after the measurement start condition is satisfied. Then, after the notification, the connection unit  32  transmits the measurement start command to the blood pressure monitor  2  to prohibit the operation of the notification unit  36 . In this manner, when the measurement start condition is satisfied, the start of measurement is notified a certain period of time after the satisfaction, before the measurement is started. This enables the subject to behave from sensing of the start of measurement, as is the case with typical blood pressure monitors. 
     Then, when the measurement result is received from the blood pressure monitor  2  through the connection unit  32 , the control unit  37  may notify the end of measurement using a ringtone produced by the speaker  39  of the notification unit  36  or vibration caused by the vibration member  40  of the notification unit  36 . In this way, when the measurement result is received from the blood pressure monitor  2 , the end of measurement is notified by the ringtone or vibration, thus allowing the end of the blood pressure measurement to be reliably notified to the subject. 
     When the operation unit  33  receives the start operation, the control unit  37  may perform, for example, an operation described below instead of immediately starting the determination of whether the measurement start condition is satisfied. In other words, for example, when the operation unit  33  receives the start operation, the inquiry unit  44  of the control unit  37  can inquire of the blood pressure monitor  2  via the connection unit  32  whether measurement preparation for the blood pressure measurement unit  23  is complete. For example, when an inquiry is received from the information processing device  3  through the blood pressure monitor connection unit  26 , the blood pressure monitor control unit  27  detects the state of wrapping of the cuff  22  of the blood pressure measurement unit  23  around the measured site, and in a case where the state of wrapping is determined to enable the blood pressure measurement, transmits a measurement preparation completion notification to the information processing device  3  through the blood pressure monitor connection unit  26 . The control unit  37  starts determining whether the measurement start condition is satisfied, for example, when the connection unit  32  receives the measurement preparation completion notification. This eliminates the possibility that the blood pressure measurement is started before the state required to measure the blood pressure of the subject is established, and even in a case where the operation member is separate from the blood pressure monitor  2 , the measurement can be made reliable, while the safety of the measurement can be ensured. 
     For example, when the operation unit  33  receives the start operation, the operation guidance unit  42  of the control unit  37  may display, on the display screen  38  of the display unit  34 , a guidance message prompting movement of the information processing device  3  to satisfy the measurement start condition, or audibly output the guidance message through the speaker  39 . In this way, how to actually start the measurement can be indicated to the subject. 
     Note that the measurement start condition, used as a reference for the determination unit  41  of the control unit  37 , may be that, for example, the angle of the display screen  38  of the display unit  34  equals a measurement start angle at which the subject is prevented from viewing the display screen  38 . For example, the sensor  35  such as an acceleration sensor or a gyroscopic sensor can detect the angle of the display screen  38  with respect to the gravitational direction, that is, the direction in which the display screen  38  faces. Thus, for example, when the display screen  38  is at an angle at which the display screen  38  approximately faces the ground direction, that is, the gravitational direction, the information processing device  3  can be determined to be laid face down on a desk or the like, and this state may be determined to indicate that the angle of the display screen  38  equals the measurement start angle. The start operation of the operator can also be performed, for example, by touching an icon or a button image on the display screen  38 , and of course the operator needs to be able to view the display screen  38 . In a case where the operator performs the start operation with the information processing device  3  in hand rather than with the information processing device  3  placed on a desk or the like, the display screen  38  generally substantially directly faces the face of the subject. Consequently, the measurement start angle may be, for example, an angle exceeding a predetermined angle with respect to the angle of the display screen  38  when the operator performs the start operation, for example, an angle exceeding the range of ±90 degrees from the angle of the display screen  38 . Thus using the angle of the display screen  38  as an indicator allows the subject to be easily determined to be prevented from viewing the display content of the display screen  38 . 
     Alternatively, the measurement start condition, used as a reference of the determination unit  41  of the control unit  37 , may be, for example, that the display screen  38  of the display unit  34  is covered. For example, in a case where the information processing device  3  is placed in a notebook type cover, closing the cover covers the display screen  38  to prevent the subject from viewing the display screen  38 . When the information processing device  3  is laid face down on a desk or the like, the display screen  38  is covered by a top plate of the desk. Whether the display screen  38  of the display unit  34  is covered may be determined, for example, based on the illuminance of the display screen  38  detected by a sensor  35  such as the illuminance sensor  35 B or the front camera  35 A provided on the front surface of the information processing device  3 . In this way, by using, as an indicator, whether the display screen  38  is covered, the subject can be easily determined to be prevented from viewing the display content of the display screen  38 . 
     The measurement start condition, used as a reference for the determination unit  41  of the control unit  37 , may be, for example, that the line of sight of the operator operating the operation unit  33  is away from the display screen  38  of the display unit  34 . When the operator performs the start operation, the operator views the display screen  38 . Thus, for example, the line of sight of the operator is detected by a known line-of-sight detection technique utilizing the sensor  35  such as the front camera  35 A of the information processing device  3 , and in a case where the line of sight detected is away from the display screen, it is determined that the operator is prevented from viewing the display content of the display screen  38 . Consequently, for example, whether the line of sight of the operator is away from the display screen  38  of the display unit  34  can be determined based on an image captured by the front camera  35 A. In this way, by using, as an indicator, whether the line of sight of the subject corresponding to the operator is away from the display screen  38 , the subject can be easily determined to be prevented from viewing the display content of the display screen  38 . 
     The measurement start condition, which is a reference of the determination unit  41  of the control unit  37 , may be that, for example, when the operation unit  33  receives the start operation, the blood pressure monitor  2  is present at a rear surface of the information processing device  3  opposite to the display screen  38  of the display unit  34 . In a case where the operator operating the operation unit  33  differs from the subject of the blood pressure, the positional relationship between the subject and the information processing device  3  varies, and it is difficult to determine which orientation of the display screen  38  prevents the subject from viewing the display content of the display screen  38 . However, in a case where the blood pressure monitor  2  is present at the rear surface of the information processing device  3  at least when the start operation is performed, the subject to which the blood pressure monitor  2  is attached is reliably present opposite to the display screen  38 . For example, the sensor  35  such as the rear camera of the information processing device  3  is utilized to extract, from an image acquired by the rear camera, a logo of the product name of the blood pressure monitor  2 , the model number of the blood pressure monitor  2 , or the like, and depending on whether the logo or the model number corresponds to a particular or preset blood pressure monitor  2 , whether the blood pressure monitor  2  is present opposite to the display screen  38  can be determined. In this way, by using, as an indicator, whether the blood pressure monitor  2  is present at the rear surface of the information processing device  3 , the subject can be easily determined to be prevented from viewing the display content of the display screen  38 . 
     Alternatively, for example, when the operation unit  33  receives the start operation, the control unit  37  may change the display on the display screen  38  of the display unit  34  to a display state in which the subject is prevented from viewing the display. The measurement start condition, used as a reference for the determination unit  41  of the control unit  37 , may be determined to be satisfied when the display content of the display screen  38  changes to the display state in which the subject is prevented from viewing the display. For example, forcibly dimming the display screen  38  reliably prevents the subject from viewing the display content of the display screen  38 . However, sudden erasure of the display screen may be mistaken for a failure or may surprise the subject, adversely affecting the blood pressure measurement. Thus, the display on the display screen  38  may be gradually dimmed, and in a case where the display has been dimmed to a certain degree, the measurement start condition may be determined to be satisfied. Alternatively, the control unit  37  may, for example, forcibly activate a screen saver when the operation unit  33  receives the start operation. In this way, by using, as an indicator, whether the display on the display screen  38  has changed to the state where the subject is prevented from viewing the display content of the display screen  38 , the subject can be easily determined to be prevented from viewing the display content of the display screen  38 . 
     Note that the notification unit  43  of the control unit  37  may, for example, display, on the display screen  38  of the display unit  34 , a message prompting the blood pressure measurement with the blood pressure monitor  2 , or may audibly output the message with the speaker  39  at a preset date and time or when the date and time is approached. Subsequently, the control unit  37  performs control to gradually dim the display on the display screen  38  of the display unit  34 . Then, in a case where communication with the blood pressure monitor  2  is established within a certain period of time while the display is gradually dimmed, the display of the display screen  38  is recovered to the original state and determination of whether the measurement start condition is satisfied is started. Thus, at or near the date and time of the start of the measurement, the message prompting the blood pressure measurement on the blood pressure monitor is displayed or audibly outputted so as to prompt the subject to measure blood pressure at a preset date and time, and prevent a measurement forget. Moreover, when the display is gradually dimmed after the message prompting the blood pressure measurement is output, even in a case where the subject is operating any other application program on the information processing device  3 , the operation is made difficult, allowing the subject to be diverted to the blood pressure measurement. 
     For example, when the measurement start condition is no longer satisfied after the connection unit  32  transmits the measurement start command to the blood pressure monitor  2 , the control unit  37  may transmit a measurement stop command to the blood pressure monitor  2  through the connection unit  32 . When, for example, the measurement stop command is received from the information processing device  3  through the blood pressure monitor connection unit  26 , for example, the blood pressure monitor control unit  27  discontinues the measurement of blood pressure and causes a fluid in the fluid bag  24  to be discharged in a case where a compressed state by the fluid bag  24  provided in the cuff  22  of the blood pressure measurement unit  23  continues for a certain period of time or longer. In other words, for example, in the sense of a switch for emergency discharge (stop) in preparation for a case where an abnormality occurs in the fluid feeding mechanism of the blood pressure monitor  2  and the compressed state by the fluid bag  24  continues, “in a case where the compressed state continues for longer than a certain period of time and the information processing device  3  in, for example, a face-down state is suddenly moved,” processing for emergency stop can be executed. In this way, when the measurement start condition is no longer satisfied, the blood pressure measurement is discontinued and the fluid in the fluid bag  24  is discharged in a case where the compressed state by the fluid bag  24  of the cuff  22  continues for a certain period of time or longer. Thus, even in a case where the operation member is separate from the blood pressure monitor  2 , the safety can be ensured. 
     In a case where the blood pressure monitor  2  further includes the emergency stop button  28  dedicated to emergency stop or also used as another button, in response to an operation of the emergency stop button, the blood pressure monitor control unit  27 , for example, discontinues the measurement of the blood pressure and causes the fluid in the fluid bag  24  contained in the cuff  22  of the blood pressure measurement unit  23  to be discharged. In this way, in response to the operation of the emergency stop button  28  provided in the blood pressure monitor  2 , the blood pressure monitor  2  discontinues the blood pressure measurement and causes the fluid in the fluid bag  24  to be discharged, ensuring safety. 
     Effect of Application Example 
     As described above, in the biometric data measurement system  1  according to the application example, the blood pressure monitor  2  is caused to start the blood pressure measurement on condition that the subjected is prevented from viewing the display content of the display screen  38  of the display unit  34 . Consequently, regardless of whatever content is caused to be displayed on the display unit  34  by an application program executed by the information processing device  3  in the background during the blood pressure measurement with the blood pressure monitor  2 , the subject is prevented from viewing the content. This prevents the subject from being upset by the display content or being subjected to a rise in blood pressure due to the display content. Consequently, even in a case where the information processing device  3  is used as a user interface for the blood pressure monitor  2 , accurate blood pressure measurements can be performed. 
     Note that the application example has been described in which, as an example, the biometric data measurement device is the blood pressure monitor  2  but that the biometric data measurement device is not limited to a blood pressure monitor and may of course be a device measuring other biometric data such as an electrocardiographic measurement device measuring electrocardiographic data. 
     Embodiments will be described below. Note that, in the following embodiments, the case in which the biometric data measurement device is a blood pressure monitor will be described as an example as is the case with the application example but that the biometric data measurement device is not limited to the blood pressure monitor and may be a device measuring other biometric data. 
     &lt;1&gt; First Embodiment 
     Now, a first embodiment will be described. 
     &lt;1-1&gt; Configuration 
     A configuration example of a biometric data measurement system according to the first embodiment will be described using  FIGS. 3 and 4 . As described above in the application example, the biometric data measurement system according to the first embodiment includes a blood pressure monitor  200  that measures the blood pressure of the subject, which is an example of the biometric data measurement device, and an information processing device  300  that controls a blood pressure measurement operation by the blood pressure monitor  200 .  FIG. 3  is a block diagram illustrating an example of a configuration of the blood pressure monitor  200  in the biometric data measurement system according to the first embodiment.  FIG. 4  is a block diagram illustrating an example of a configuration of the information processing device  300  in the biometric data measurement system according to the first embodiment. 
     In the example of  FIG. 3 , the blood pressure monitor  200  is, for example, an electronic blood pressure monitor including a blood pressure monitor body  201  and a cuff  202  wrapped around a measured site such as the upper arm or wrist of the subject. 
     The cuff  202  corresponds to the cuff  22  as described above in the application example, and for example contains a fluid bag  203  corresponding to the fluid bag  24  as described above in the application example. 
     The blood pressure monitor body  201  corresponds to the blood pressure monitor body  21  as described above in the application example, and includes, for example, a control unit  204 , an oscillation circuit  205  connected to the control unit  204  via a bus, a pump drive circuit  206 , a valve drive circuit  207 , an input/output interface  208 , and a communication interface  209 . Furthermore, the blood pressure monitor body  201  includes, for example, a pressure sensor  210  connected to the oscillation circuit  205 , a piezoelectric pump  211  connected to the pump drive circuit  206 , a valve  212  connected to the valve drive circuit  207 , tubing  213  connecting the fluid bag  203  contained in the cuff  202  and a pressure sensor  210 , a piezoelectric pump  211 , and a valve  212 , and a cuff wrapping state detection unit  214  and a power switch  215  connected to the input/output interface  208 . Although not illustrated in particular, a power supply unit is provided that supplies power to each unit in the blood pressure monitor body  201 . Note that, in  FIG. 3 , the input/output interface and the communication interface are described as “input/output I/F” and “communication I/F”, respectively. 
     The control unit  204  includes, for example, a CPU  216 , a RAM  217 , a ROM  218 , and the like, and controls each component of the blood pressure monitor  200  according to the information processing. Instead of the CPU  216 , any other processor such as an MPU may be used. The ROM  218  stores a program (e.g., a blood pressure measurement program) executed by CPU  216 , for example. The RAM  217  is, for example, a memory used as a work memory by the CPU  216 . 
     The CPU  216  may execute the required program to perform processing of the blood pressure monitor control unit  27  as described above in the application example. When the CPU  216  executes the required program, for example, the program to be executed which is stored in ROM  218  is developed into RAM  217 . Then, the CPU  216  interprets and executes the program developed in the RAM  217  to control each component, for example. 
     The input/output interface  208  can, for example, input a detection signal from the cuff wrapping state detection unit  214  and an operation signal from the power switch  215  to the CPU  216 . 
     The cuff wrapping state detection unit  214  corresponds to the detection unit  25  as described above in the application example, and detects the state of wrapping of the cuff  202  around the upper arm or wrist, corresponding to a measured site of the subject. 
     The cuff wrapping state detection unit  214  may detect the state of wrapping of the cuff  202  by detecting, for example, a state of electrical connection of an electrical contact provided in the cuff  202 , marks aligned along the longitudinal direction of the cuff  202  and optically detected, a wrapping shape of the cuff  202  detected by a shape sensor such as a fiber sensor inserted through the cuff  202  in the longitudinal direction, and the like. 
     The power switch  215  is, for example, a switch turned on/off in response to the operation of a power button disposed on the surface of the blood pressure monitor body  201 , and receives an instruction to turn on/off the power supply and an instruction for an emergency stop of the blood pressure measurement. The on/off instruction for the power supply and the instruction for an emergency stop of the blood pressure measurement can be distinguished, for example, by the on time of the power switch  215 . For example, turn-on for at least a predetermined period of time such as two seconds, that is, long depression of the power button, corresponds to the on/off instruction for the power supply, and turn-on for shorter than two seconds, that is, short depression of the power button, corresponds to the instruction for an emergency stop of the blood pressure measurement. The operation signal indicating the on/off state of the power switch  215  is input to the CPU  216 , for example, via the input/output interface  208 . For example, based on the operation signal, the CPU  216  discriminates the on/off instruction for the power supply from the instruction for an emergency stop of the blood pressure measurement. Thus, the power switch  215  (power button) corresponds to the emergency stop button  28  as described above in the application example. 
     The communication interface  209  corresponds to the blood pressure monitor connection unit  26  as described in the above application example, and may be, but is not limited to, a near field wireless communication interface, for example, a BLE communication module. The communication interface  209  may be a wired communication interface, for example, a USB interface that communicates via a USB cable. 
     The following can constitute the blood pressure measurement unit  23  measuring the blood pressure of the subject as described above in the application example: the cuff  202  containing the fluid bag  203 , and the pressure sensor  210 , the piezoelectric pump  211 , the valve  212 , the tubing  213 , the oscillation circuit  205 , the pump drive circuit  206 , and the valve drive circuit  207  in the blood pressure monitor body  201 . 
     The pressure sensor  210  may be, for example, a piezoresistive pressure sensor. The oscillation circuit  205  converts an output from the pressure sensor  210  into a frequency, for example. The piezoelectric pump  211  is, for example, a pump that feeds air as a fluid to the fluid bag  203 . The pump drive circuit  206  drives the piezoelectric pump  211 , for example. The valve  212  is a valve that is opened and closed to adjust, for example, the pressure on a discharge side of the piezoelectric pump  211 , i.e., the pressure in the fluid bag  203  (hereinafter referred to as the back pressure). The valve drive circuit  207  drives the valve  212 , for example. The tubing  213  connects, for example, the pressure sensor  210 , the piezoelectric pump  211 , the valve  212 , and the fluid bag  203  contained in the cuff  202 , for example, and allow air as a fluid to circulate among the pressure sensor  210 , the piezoelectric pump  211 , the valve  212 , and the fluid bag  203  contained in the cuff  202 . 
     For example, in accordance with a program for controlling the blood pressure monitor  200  stored in the ROM  218 , the CPU  216  performs control to drive the piezoelectric pump  211  via the pump drive circuit  206  and to drive the valve  212  via the valve drive circuit  207  in response to reception of a measurement start command from the information processing device  300  through the communication interface  209 . 
     The piezoelectric pump  211  feeds air as a fluid to the fluid bag  203 , for example, to increase the pressure (back pressure) in the fluid bag  203  contained in the cuff  202 . The pump drive circuit  206 , for example, drives the piezoelectric pump  211  based on a control signal provided by the CPU  216 . The valve drive circuit  207 , for example, opens and closes the valve  212  based on a control signal provided by the CPU  216 . The valve  212  is opened and closed to control the back pressure, for example, by discharging air from the fluid bag  203  or sealing air in the fluid bag  203 . 
     The pressure sensor  210  and the oscillation circuit  205  operate as pressure detection units that detect back pressure, for example. The pressure sensor  210  is, for example, a piezoresistive pressure sensor connected via the tubing  213  to the piezoelectric pump  211 , the valve  212 , and the fluid bag  203  contained in the cuff  202 . In this example, the oscillation circuit  205 , for example, oscillates based on an electrical signal from the pressure sensor  210  based on a change in electric resistance due to a piezoresistive effect and outputs, to the CPU  216 , a frequency signal having a frequency corresponding to an electrical signal value from the pressure sensor  210 . 
     The CPU  216 , for example, calculates the current pressure of the fluid bag  203  based on the frequency signal input from the oscillation circuit  205 . The CPU  216 , for example, performs control to calculate a blood pressure value based on the pressure of the fluid bag  203 , and to transmit the blood pressure value calculated to the information processing device  300  through the communication interface  209 . 
     In the example illustrated in  FIG. 4 , the information processing device  300  includes, for example, a control unit  301 , and components connected to the control unit  301  via a bus and including a storage unit  302 , an image processing circuit  303 , and a sound processing unit  304 , a communication interface  305 , a graphics controller  306 , a touch panel controller  307 , an input/output interface  308 , a wireless communication interface  309 , and a clock circuit  310 . For example, a front camera  311  and a rear camera  312  are connected to the image processing circuit  303 . For example, a microphone  313  and a speaker  314  are connected to the sound processing unit  304 . For example, a display unit  315  is connected to the graphics controller  306  and the touch panel controller  307 . The display unit  315  includes, for example, a display screen  316  and a touch panel  317 . The display screen  316  is, for example, connected to the graphics controller  306 , and the touch panel  317  is, for example, connected to the touch panel controller  307 . The input/output interface  308  connects to, for example, an acceleration sensor  318 , an illuminance sensor  319 , an operation member  320 , and a vibrator  321 . Note that, in  FIG. 4 , the input/output interface and the communication interface are described as “input/output I/F” and “communication I/F”, respectively. 
     The control unit  301  includes, for example, a CPU  322 , a RAM  323 , a ROM  324 , and the like, and controls each component according to information processing. Instead of the CPU  322 , any other processor such as an MPU may be used. The ROM  324 , for example, stores an operating system and any other program executed by the CPU  322 . The RAM  323  is, for example, a memory used as a work memory by the CPU  322 . 
     The CPU  322 , for example, executes the required program to perform processing of the control unit  37 , for example, the determination unit  41 , the operation guidance unit  42 , the notification unit  43 , the inquiry unit  44 , and the like as described above in the application example. The program may be, for example, stored in the storage unit  302  instead of the ROM  324 . When the CPU  322  executes the required program, for example, the program to be executed that is stored in the ROM  324  and/or the storage unit  302  is developed into the RAM  323 . Then, the CPU  322  interprets and executes the program developed in the RAM  323 , and controls each component. 
     The storage unit  302  can store, for example, programs executed by the control unit  301  (e.g., an email application program, a messaging application program, and a blood pressure measurement application program), setting data needed to execute the program (e.g., data such as a mail server for emails and passwords), user specific information using information processing device  300 , and so on. A storage medium included in the storage unit  302  may be any medium that accumulates information such as the programs by an electrical, magnetic, optical, mechanical, or chemical action such that a computer, a machine, and the like can read out the information such as the programs recorded. For example, an Electrically Erasable Programmable Read-Only Memory (EEPROM, trade name) or the like can be used as the storage medium included in the storage unit  302 . Note that the storage unit  302  may be used as a work memory by the CPU  322 . 
     For example, under the control of the CPU  322 , the image processing circuit  303  performs predetermined image processing such as resizing, correction processing, filtering, or the like, on the image acquired by the front camera  311  and the rear camera  312 . Here, the front camera  311  corresponds to the front camera  35 A as described above in the application example, and the rear camera  312  corresponds to the rear camera as described above in the application example. For example, when the current camera image is displayed on the display screen  316  of the display unit  315  for composition during camera image capturing, the image processing circuit  303  resizes the images acquired by the front camera  311  or the rear camera  312  to the size (resolution) of the display screen  316 , and stores the images in the RAM  323 . When a certain image effect is applied by the camera application program, the CPU  322  may perform, for example, image processing corresponding to the effect on the image stored in the RAM  323 , and display the image on the display screen  316 . The image processing circuit  303  may have the function for image processing. For example, in response to a release operation by the operator, the image processing circuit  303  converts the image acquired by the front camera  311  or the rear camera  312  into an image of the set resolution, and stores the image in the storage unit  302 . At this time, as in the case of display on the display screen  316 , image processing can be executed on the image stored in the storage unit  302 . 
     The sound processing unit  304  performs, for example, sound processing such as digital conversion, noise removal, or echo cancellation on a voice signal input from the microphone  313 , and outputs the processed signal to the CPU  322 . Under the control of the sound processing units  304  and the CPU  322 , the voice signal generated by performing voice processing such as voice synthesis is output to the speaker  314 . Here, the microphone  313  corresponds to the microphone as described above in the application example, and the speaker  314  corresponds to the speaker  39  of the notification unit  36  as described above in the application example. 
     The communication interface  305  corresponds to the connection unit  32  as described above in the application example, and is in near field wireless communication with, for example, the communication interface  209  of the blood pressure monitor  200 . For example, the communication interface  305  may be, but is not limited to, a BLE communication module. For example, the communication interface  305  may be a wired communication interface such as a USB interface that communicates via a USB cable. 
     The graphics controller  306  is, for example, a display controller that controls the display screen  316  of the display unit  315 . The display unit  315  corresponds to the display unit  34  as described in the application example. The display screen  316  corresponds to the display screen  38  as described above in the application example, and may be, for example, a liquid crystal display or an organic electroluminescent display. 
     The touch panel controller  307 , for example, controls the touch panel  317 , corresponding to a coordinate detection device disposed on the display screen  316 . The touch panel controller  307 , for example, acquires, from the touch panel  317 , coordinate data indicating a touch position on the display screen  316  touched by the operator, and outputs the acquired coordinate data to the CPU  322 . 
     The input/output interface  308  can, for example, input, to the CPU  322 , a detection signal from the acceleration sensor  318  or the illuminance sensor  319 , an operation signal from the operation member  320 , and the like. The input/output interface  308  can, for example, output a vibration instruction from the CPU  322  to the vibrator  321 . 
     The acceleration sensor  318  corresponds to the acceleration sensor as described above in the application example, and for example, detects the acceleration of the information processing device  300 . The acceleration sensor  318  is, for example, not limited to detection of the accelerations in the directions of the X, Y, and Z axes, and may detect the acceleration in the rotational direction around each axis. The acceleration sensor  318  outputs an acceleration signal indicating the accelerations in the directions of the three axes and the acceleration in the rotational direction around each axis to the CPU  322  via the input/output interface  308 . Note that instead of or in addition to the acceleration sensor  318 , the information processing device  300  may include, for example, a gyroscopic sensor. The gyroscopic sensor corresponds to the gyroscopic sensor as described above in the application example, and can detect the angle of rotation when the information processing device  300  rotates around each of the X, Y, and Z axes, and output a rotation angle signal indicating the angle of rotation around each of the axes. 
     The illuminance sensor  319  corresponds to the illuminance sensor  35 B as described above in the application example. The illuminance sensor  319  is, for example, a photodiode and detects the ambient brightness of the information processing device  300 . In the present embodiment, the illuminance sensor  319  is disposed at a position near the display screen  316  on the front surface of the information processing device  300 , and outputs a brightness signal indicating the ambient brightness of the display screen  316  to the CPU  322  via the input/output interface  308 . Generally, the illuminance sensor  319  is utilized to adjust the brightness (luminance) of the display screen  316  in accordance with the ambient brightness. 
     Note that instead of or in addition to the illuminance sensor  319 , the information processing device  300  may include, for example, a proximity sensor. The proximity sensor is a sensor that detects, in a non-contact manner, that an object to be detected has approached, and the proximity sensor is typically utilized to prevent the touch panel  317  from functioning when a phone call is made. Specifically, known examples of the proximity sensor include a high-frequency oscillating type utilizing electromagnetic induction, a magnetic type using a magnet, and a capacitive type that detects a change in capacitance between the object to be detected and the sensor, and the like. When detecting that the object to be detected has approached, the proximity sensor can output a proximity signal indicating that the object to be detected has approached. 
     The operation member  320  includes a switch that detects the operation of various operation buttons including the operation button  33 A, for example, as described above in the application example. The operation member  320  can detect the operation of the operation button by the operator, and output an operation signal indicating the content of the operation to the CPU  322  via the input/output interface  308 . The operation member  320 , the touch panel  317  disposed on the display screen  316 , and the touch panel controller  307  that controls the touch panel  317  correspond to the operation unit  33  as described above in the application example. 
     The vibrator  321  corresponds to the vibration member  40  of the notification unit  36  as described above in the application example. The vibrator  321  produces vibration in response to a vibration instruction provided by the CPU  322  via the input/output interface  308 . 
     The wireless communication interface  309  corresponds to a communication unit  31  as described above in the application example, and may include, for example, a Wi-Fi module. The wireless communication interface  309  is, for example, connected to the communication network NW such as the Internet or a telephone network via a Wi-Fi base station not illustrated, and can communicate with an external device via the communication network NW. 
     The clock circuit  310  includes, for example, a clock, and can acquire the current date and time. 
     &lt;1-2&gt; Operation 
     Now, an operation example of the biometric data measurement system according to the first embodiment will be described using  FIGS. 5 and 6 . 
       FIG. 5  is a flowchart illustrating an example of a processing procedure for the information processing device  300  in accordance with the blood pressure measurement application program. The processing procedure is started, for example, when the touch panel  317  is operated at a position corresponding to the icon of the blood pressure measurement application program displayed on the display screen  316 , and the CPU  322  determines that activation of the blood pressure measurement application program has been instructed.  FIG. 6  is a flowchart illustrating an example of a processing procedure for the blood pressure monitor  200 . The processing procedure is started, for example, when the CPU  216  determines that power-on has been instructed based on an operation signal from the power switch  215  in response to the operation, by the subject, of the power button disposed on the front surface of the blood pressure monitor body  201 . 
     Note that the processing procedure described below is merely an example, and each process may be changed to the extent possible. Further, in the processing procedure described below, steps can be omitted, substituted, and added in accordance with the embodiment as appropriate. 
     &lt;1-2-1&gt; Communication Establishment Operation 
     [Step S 301 ] 
     First, the CPU  322  of the information processing device  300  establishes near field communication with the blood pressure monitor  200  through the communication interface  305 . 
     [Step S 201 ] 
     The CPU  216  of the blood pressure monitor  200  similarly establishes a near field communication with the information processing device  300  through the communication interface  209 . 
     &lt;1-2-2&gt; Measurement Start Determination Operation 
     [Step S 302 ] 
     The CPU  322  of the information processing device  300  waits for the operator to perform the start operation for the blood pressure measurement after establishing near field communication with the blood pressure monitor  200 . In other words, the CPU  322  causes the graphics controller  306  to display, on the display screen  316  of display unit  315 , an initial screen for the blood pressure measurement application program including the icon  38 A for instructing the start of the blood pressure measurement as described above in the application example. Then, the CPU  322  determines whether the position on the touch panel  317  corresponding to the icon  38 A has touched, based on touch coordinates input from the touch panel controller  307 . In a case where the blood pressure measurement start operation is determined not to have been performed (step S 302 , NO), the CPU  322  repeats the processing in step S 302 . In a case where the blood pressure measurement start operation is determined to have been performed (step S 302 , YES), the CPU  322  advances the processing to step S 303 . 
     [Step S 303 ] In a case that in step S 302 , the blood pressure measurement start operation is determined to have been performed (step S 302 , YES), the CPU  322  executes measurement start determination processing to instruct the blood pressure monitor  200  to start measurement when the measurement start condition is satisfied.  FIG. 7  is a flowchart illustrating an example of a processing procedure for the information processing device. 
     [Step S 303 A] 
     In the measurement start determination processing, the CPU  322  first acquires the initial angle of the display screen initial angle. For example, based on the detection signal from the acceleration sensor  318  acquired via the input/output interface  308 , the CPU  322  can calculate the angle of the information processing device  300 , that is, the display screen  316  with respect to the gravitational direction, in other words, the direction in which display screen  316  faces. The acquired initial angle of the display screen is stored in the RAM  323  or the storage unit  302 . 
     [Step S 303 B] 
     Then, the CPU  322  outputs, through the display screen  316  and/or the speaker  314 , a measurement start guidance message prompting movement of the information processing device  300  to satisfy the measurement start condition. For example, the CPU  322  may can cause the graphics controller  306  to display the characters of the measurement starting guidance message on the display screen  316 , and cause the sound processing unit  304  to emit the voice of the measurement start guidance message through the speaker  314 . For example, the content of the measurement start guidance message is stored in the storage unit  302  in advance as a part of the blood pressure measurement application program. Thus, the CPU  322  can perform the processing of the operation guidance unit  42  as described above in the application example. 
     [Step S 303 C] 
     Then, the CPU  322  transmits an inquiry for measurement preparation completion to the blood pressure monitor  200  through the communication interface  305 . Thus, the CPU  322  may perform processing of the inquiry unit  44  as described above in the application example. 
     [Step S 303 D] 
     Subsequently, the CPU  322  determines whether a measurement preparation completion notification has been received from the blood pressure monitor  200  through the communication interface  305 . In a case where the measurement preparation completion notification is determined not to have been received (step S 303 D, NO), the CPU  322  advances the processing to step S 303 E. In a case where the measurement preparation completion notification is determined to have been received (step S 303 D, YES), the CPU  322  advances the processing to step S 303 H. 
     [Step S 303 E] 
     In step S 303 D described above, in a case where the measurement preparation completion notification is determined not to have been received from the blood pressure monitor  200  (Step S 303 D, NO), the CPU  322  determines whether a predetermined period of time, for example, 5 seconds have elapsed since the transmission of the inquiry for measurement preparation completion. The 5 seconds are illustrative and no such limitation is intended. In a case where the predetermined period of time is determined not to have elapsed (step S 303 E, NO), the CPU  322  returns the processing to step S 303 D described above. In a case where the predetermined period of time is determined to have elapsed (step S 303 E, YES), the CPU  322  advances the processing to step S 303 F. 
     Thus, by repeating the processing in steps S 303 D and S 303 E, the CPU  322  waits for the predetermined period of time to receive the measurement preparation completion notification. 
     [Step S 202 ] 
     After establishing near field communication with the information processing device  300 , the CPU  216  of the blood pressure monitor  200  waits to receive an inquiry for measurement preparation completion from the information processing device  300 . In other words, the CPU  216  determines whether the inquiry for measurement preparation completion has been received from the information processing device  300  through the communication interface  209 . In a case where the inquiry for measurement preparation completion is determined not to have been received (step S 202 , NO), the CPU  216  repeats the processing in step S 202 . In a case where the inquiry for measurement preparation completion is determined to have been received (step S 202 , YES), the CPU  216  advances the processing to step S 203 . 
     [Step S 203 ] 
     In step S 202  described above, in a case where the inquiry for measurement preparation completion is determined to have been received from the information processing device  300  (step S 202 , YES), the CPU  216  determines whether the blood pressure measurement is enabled to be performed. For example, the CPU  216  can determine whether the measurement has been enabled or not, based on of the state of wrapping of the cuff  202  indicated by the detection signal acquired from the cuff wrapping state detection unit  214  via the input/output interface  208 . In a case where the blood pressure measurement is determined not to have been enabled (step S 203 , NO), the CPU  216  advances the processing to step S 204 . In a case where the blood pressure measurement is determined to have been enabled (step S 203 , YES), the CPU  216  advances the processing to step S 205 . 
     [Step S 204 ] 
     In step S 203  described above, in a case where the blood pressure measurement is determined not to have been enabled (step S 203 , NO), the CPU  216  causes the communication interface  209  to determine whether the end of the inquiry has been received from the information processing device  300 . In a case where the end of the inquiry is determined not to have been received (step S 204 , NO), the CPU  216  returns the processing to step S 203  described above. 
     [Step S 303 F] 
     In step S 303 E described above, in a case where a predetermined period of time is determined to have elapsed with the measurement preparation completion notification not received from the blood pressure monitor  200  (step S 303 E, YES), the CPU  322  outputs an error message via the display screen  316  and/or the speaker  314 . For example, the CPU  322  causes the graphics controller  306  to display the characters of an error message on the display screen  316 , and causes the sound processing unit  304  to emit the voice of the error message through the speaker  314 . For example, the content of the error message is stored in the storage unit  302  in advance as a part of the blood pressure measurement application program. The content of the error message may include a message indicating that the blood pressure monitor  200  is not ready, or an instruction message for an instruction to correctly re-wrap the cuff  202 . 
     [Step S 303 G] 
     Subsequently, the CPU  322  transmits the end of the inquiry to the blood pressure monitor  200  through the communication interface  305 . Then, the measurement start determination process is ended, and the processing is returned to step S 302 . 
     [Step S 204 ] 
     In step S 204  described above, in a case where the end of the inquiry is determined to have been received (step S 204 , YES), the CPU  216  of the blood pressure monitor  200  returns the processing to step S 202  above. In other words, when the preparation is not complete even after the predetermined period of time has elapsed since the inquiry for the measurement preparation completion, the information processing device  300  outputs an error message, and in response, the subject re-wraps the cuff  202  and performs the measurement start operation again using the information processing device  300 . Thus, the CPU  216  returns the processing back to step S 202  described above and waits to receive an inquiry for measurement preparation completion from the information processing device  300 . 
     [Step S 205 ] 
     In contrast, in step S 203  described above, in a case where the blood pressure measurement is determined to have been enabled (step S 203 , YES), the CPU  216  transmits a measurement preparation completion notification to the information processing device  300  through the communication interface  209 . 
     [Step S 303 H] 
     In step S 303 D described above, in a case where the measurement preparation completion notification is determined to have been received from the blood pressure monitor  200  (step S 303 D, YES), the CPU  322  of the information processing device  300  acquires the current angle of the display screen  316 . For example, based on the detection signal from the acceleration sensor  318  acquired via input/output interface  308 , the CPU  322  calculates the angle of the information processing device  300 , that is, the display screen  316  with respect to the gravitational direction, in other words, the direction in which display screen  316  faces. The acquired current angle of the display screen is stored in the RAM  323  or the storage unit  302 . 
     [Step S 303 I] 
     Then, the CPU  322  determines whether the difference between the initial angle and the current angle of the display screen  316  stored in the RAM  323  or the storage unit  302  is outside the range of the predetermined angle, for example, the range of ±90 degrees. The ±90 degree are illustrative and no such limitation is intended. The predetermined angle is stored in the storage unit  302  in advance as a part of the blood pressure measurement application program. As described above in the application example, in a case where, for example, the angle difference exceeds the range of ±90 degrees, the angle may be determined to equal a measurement start angle at which the subject is prevented from viewing the display screen. However, this difference in angle is with respect to one of the x-axis corresponding to the left-right direction (lateral direction) of the display screen  316  or the y-axis corresponding to the vertical direction (longitudinal direction), and the angle related to the z-axis corresponding to the front-back direction (depth direction) is not included in this determination. In a case where the angle difference is determined to not to be outside the range of ±90 degrees (step S 303 I, NO), the CPU  322  returns the processing to step S 303 H described above. In a case where the angle difference is determined to be outside the range of ±90 degrees (step S 303 I, YES), the CPU  322  determines that the measurement start condition is satisfied to end the measurement start determination processing and advances the processing proceeds to step S 304 . In this way, the CPU  322  can execute the processing of the determination unit  41  in which the measurement start condition is determined to be satisfied when the angle of the display screen  38  equals the measurement start angle at which the subject is prevented from viewing the display screen  38 , as described above in the application example. 
     [Step S 304 ] 
     As described above, in a case where the measurement start condition is satisfied, the CPU  322  waits for a certain period of time, e.g., 3 seconds. The 3 seconds are illustrative and no such limitation is intended. 
     [Step S 305 ] 
     Subsequently, the CPU  322  outputs a measurement start message through the speaker  314 . In other words, the CPU  322  emits the voice of the measurement starting message from the speaker  314  through the sound processing unit  304 . For example, the content of the measurement start message is stored in the storage unit  302  in advance as a part of the blood pressure measurement application program. Note that in this case, because the subject is prevented from viewing the display content of the display screen  316 , the CPU  322  does not display the measurement start message on the display screen  316  unlike in the case of other messages. 
     [Step S 306 ] 
     Subsequently, the CPU  322  transmits a measurement start command to the blood pressure monitor  200  via the communication interface  305 . 
     In this manner, the transmission of the measurement start command is performed after a wait for a certain period of time, rather than immediately after the output of the measurement start message to the blood pressure monitor  200 . Thus, as is the case with common blood pressure monitors, the subject can behave from sensing of the start of the measurement. 
     [Step S 307 ] 
     The CPU  322  prohibits the speaker  314  and the vibrator  321  from being used by the application program running in the background. For example, the CPU  322  prevents a ringtone (ringer melody) for the reception of an email or a message in the email application program or messaging application program from being emitted from the speaker  314 . 
     Note that for a ringtone (ringer melody) for reception of a telephone call, the use of the speaker  314  is not prohibited. Unlike emails and messages, telephone calls are often used in more urgent cases and thus needs to have priority over blood pressure measurement. Some messaging application programs include a telephone call function via the Internet, and a ringtone related to telephone calls in such an application program is desirably handled similarly to incoming calls. 
     [Step S 308 ] 
     Furthermore, the CPU  322  erases the display screen  316  by, for example, stopping the supply of power from a power supply unit (not illustrated) to the display screen  316 . Erasing the display screen  316  enables suppression of the power consumption of the information processing device  3 . 
     Note that the processing in steps S 307  and S 308  may be performed before step S 306  described above or during the wait in step S 304  described above. Either of the processing in step S 307  and the processing in step S 308  may be performed before the other. Furthermore, the processing in step S 307  and/or step S 308  may be omitted. 
     [Step S 206 ] 
     After transmitting the measurement preparation completion notification to the information processing device  300  in step S 205  described above, the CPU  216  of the blood pressure monitor  200  waits to receive the measurement start command from the information processing device  300 . In other words, the CPU  216  determines whether or not the measurement start command has been received from the information processing device  300  through the communication interface  209 . In a case where the measurement start command is determined not to have been received (step S 206 , NO), the CPU  216  repeats the processing in step S 206 . In a case where the measurement start command is determined to have been received (step S 206 , YES), the CPU  216  advances the processing to step S 207 . 
     &lt;1-2-3&gt; Blood Pressure Measurement Operation 
     [Step S 207 ] 
     In a case where in step S 206  described above, the measurement start command is determined to have been received from the information processing device  300  (step S 206 , YES), the CPU  216  introduces a fluid (air) into the fluid bag  203  contained in the cuff  202  to increase the pressure (back pressure) in the fluid bag  203 . For example, the CPU  216  first closes the valve  212  via the valve drive circuit  207  and then drives the piezoelectric pump  211  via the pump drive circuit  206  to feed air to the fluid bag  203 . This inflates the fluid bag  203  while gradually increasing the back pressure. 
     [Step S 208 ] 
     Then, the CPU  216  determines whether the back pressure detected by the pressure sensor  210  is equal to or higher than a predetermined pressure based on a frequency signal input from the oscillation circuit  205 . The predetermined pressure is a pressure sufficiently higher than the systolic blood pressure of the subject (e.g. the systolic blood pressure+30 mmHg). This may be pre-stored in the ROM  218  or any other memory not illustrated, or the CPU  216  may estimate and determine the systolic blood pressure during pressurization in accordance with a predetermined calculation formula (see, e.g., JP 2001-70263). In a case where the back pressure is not equal to or higher than the predetermined pressure (step S 208 , NO), the CPU  216  advances the processing to step S 209 . In a case where the back pressure is equal to or higher than the predetermined pressure (step S 208 , YES), the CPU  216  advances the processing to step S 210 . 
     [Step S 209 ] 
     In a case where in step S 208  described above, that the back pressure is determined to be equal to or higher than the predetermined pressure (step S 208 , NO), the CPU  216  determines whether a blood pressure measurement emergency stop command has been input to the blood pressure monitor  200  or not or whether a measurement stop command has been received from the information processing device  300  or not. For example, the CPU  216  can determine whether the blood pressure measurement emergency stop instruction has been input by short depression of the power button, based on an operation signal from the power switch  215  in response to the subject operation of the power button disposed on the front surface of the blood pressure monitor body  201 . For example, the CPU  216  can determine whether the measurement stop command has been received or not based on the result of reception by the communication interface  209  that communicates with the information processing device  300 . In a case where the input of the blood pressure measurement emergency stop instruction or the reception of the measurement stop command is determined not to have been performed (step S 209 , NO), the CPU  216  returns the processing to step S 207  described above and continues pressurization. In a case where the input of the blood pressure measurement emergency stop instruction or the reception of the measurement stop command is determined to have been performed (step S 209 , YES), the CPU  216  advances the processing to step S 218 . 
     [Step S 210 ] 
     In step S 208  described above, in a case where the back pressure is determined to be equal to or higher than the predetermined pressure (step S 208 , YES), the CPU  216  deflates the fluid bag  203  and gradually reduces the back pressure. For example, the CPU  216  stops the piezoelectric pump  211  via the pump drive circuit  206  and then performs control to progressively open the valve  212  via the valve drive circuit  207 . For a depressurization rate in this case, for example, a target depressurization rate corresponding to a target during pressurization of the cuff  202  is set, and the CPU  216  controls a degree of opening of the valve  212  to achieve the target depressurization rate. 
     [Step S 211 ] 
     The CPU  216  determines whether the blood pressure measurement emergency stop instruction has been input. For example, the CPU  216  can determine whether the blood pressure measurement emergency stop instruction has been input by short depression of the power button, based on an operation signal from the power switch  215  in response to the subject operation of the power button disposed on the front surface of the blood pressure monitor body  201 . In a case where the blood pressure measurement emergency stop instruction is determined not to have been input (step S 211 , NO), the CPU  216  advances the processing to step S 212 . In a case where the blood pressure measurement emergency stop instruction is determined to have been input (step S 211 , YES), the CPU  216  advances the processing to step S 218 . 
     [Step S 212 ] 
     In step S 211  described above, in a case where the blood pressure measurement emergency stop instruction is determined not to have been input (step S 211 , NO), the CPU  216  determines whether the measurement stop command has been received from the information processing device  300 . For example, the CPU  216  can determine whether the measurement stop command has been received or not based on the result of reception by the communication interface  209  that communicates with the information processing device  300 . In a case where the measurement stop command is determined not to have been received (step S 212 , NO), the CPU  216  advances the processing to step S 213 . In a case where the measurement stop command is determined to have been received (step S 212 , YES), the CPU  216  advances the processing to step S 217 . 
     [Step S 213 ] 
     In a case where in step S 212  described above, the measurement stop command is determined not to have been received (step S 212 , NO), the CPU  216  calculates the blood pressure value. For example, in the depressurization process described above, the pressure sensor  210  detects, via the cuff  202 , a back pressure signal representing the pressure of the cuff  202 . Based on the back pressure signal, the CPU  216  can calculate the blood pressure value (systolic blood pressure and diastolic blood pressure) according to the oscillometric method. Note that the calculation of the blood pressure value is not limited to the depressurization process and may be performed during the pressurization process. 
     [Step S 214 ] 
     The CPU  216  determines whether the blood pressure value has been determined or not. For example, in a case where both systolic blood pressure and diastolic blood pressure have been calculated, the blood pressure value is determined to have been determined. In a case where the blood pressure value is determined not to have been determined (step S 214 , NO), the CPU  216  returns the processing to step S 210  described above to continue depressurization. In a case where the blood pressure value is determined to have been determined (step S 214 , YES), the CPU  216  advances the processing to step S 215 . 
     [Step S 215 ] 
     In a case where in step S 214  described above, the blood pressure value has been determined (step S 214 , YES), the CPU  216  transmits the blood pressure value calculated to the information processing device  300  through the communication interface  209 . 
     [Step S 216 ] 
     Subsequently, the CPU  216  opens the valve  212  via the valve drive circuit  207  to evacuate air in the fluid bag  203  of the cuff  202 . 
     [Step S 309 ] 
     After erasing the display screen  316  in step S 308  described above, the CPU  322  of the information processing device  300  determines whether the measurement start condition has deviated or not. As described above, the measurement start condition is, for example, that the current angle of the display screen  316  exceeds a predetermined angle from the initial angle, for example, the range of ±90 degrees. Thus, in step S 309 , whether the difference between the initial angle and the current angle of the display screen  316  is within a predetermined angle, for example within ±90 degrees. In a case where the measurement start condition is determined not to have deviated (step S 309 , NO), the CPU  322  advances the processing to step S 310 . In a case where the measurement start condition is determined to have deviated (step S 309 , YES), the CPU  322  advances the processing to step S 314 . 
     [Step S 310 ] 
     In step S 309  described above, in a case where the measurement start condition is determined not to have deviated (step S 309 , NO), the CPU  322  determines whether the blood pressure value has been received from the blood pressure monitor  200  through the communication interface  305  or not. In a case where the blood pressure value is determined not to have been received (step S 310 , NO), the CPU  322  returns the processing to step S 309  described above. In a case where the blood pressure value is determined to have been received (step S 310 , YES), the CPU  322  advances the processing to step S 311 . 
     By repeating step S 309  and step S 310 , the CPU  322  waits for the blood pressure monitor  200  to measure the blood pressure value. 
     [Step S 311 ] 
     In a case where in step S 310  described above, the blood pressure value is determined to have been received (step S 310 , YES), the CPU  322  stores the received blood pressure value in the storage unit  302 . 
     [Step S 312 ] 
     Subsequently, the CPU  322  notifies the end of the measurement. For example, the CPU  322  causes the sound processing unit  304  to emit the voice of a measurement end message from the speaker  314 . For example, the content of the measurement end message is stored in the storage unit  302  in advance as a part of the blood pressure measurement application program. In this case, the CPU  322  may further cause the vibrator  321  to vibrate via the input/output interface  308 . 
     [Step S 313 ] 
     Then, the CPU  322  displays the measurement result stored in the storage unit  302  on the display screen  316  via the graphics controller  306 . By making the display screen  316  of the information processing device  300  visible in response to the notification of the end of measurement in step S 312  described above, the subject can view the measurement result displayed on the display screen  316 . Note that the measurement result displayed on the display screen  316  may include only the currently measured blood pressure value or a previously measured blood pressure value and the current blood pressure value presented together. Furthermore, processed information may be presented such as temporal changes in blood pressure value, statistics, or the like. What measurement result is displayed depends on the blood pressure measurement application program and selection by the operator. 
     &lt;1-2-4&gt; Emergency Stop Operation 
     [Step S 209 , step S 211 ] 
     The CPU  216  of the blood pressure monitor  200  determines, in step S 209  and step S 211  described above, whether a blood pressure measurement emergency stop instruction has been input as described above. For example, in a case where the blood pressure measurement emergency stop instruction is determined to have been input by the subject by short-time turn-on of the power switch  215  based on short depression of the power button disposed on the front surface of the blood pressure monitor body  201  (step S 209  or step S 211 , YES), the CPU  216  advances the processing to step S 218 . 
     [Step S 218 ] 
     In a case where in step S 209  or step S 211  described above, the blood pressure measurement emergency stop instruction is determined to have been input by the subject (step S 209  or step S 211 , YES), the CPU  216  opens the valve  212  via the valve drive circuit  207  and evacuates air in the fluid bag  203  of the cuff  202 . The CPU  216  then returns the processing to step S 202  described above. 
     A situation where a power button functioning as an emergency stop button for the blood pressure monitor  200  is operated (when the power switch  215  is turned on for a short time) is assumed to be a case where the subject desires to immediately discontinue the blood pressure measurement. In particular, the operation of the emergency stop button during depressurization includes a case where an abnormality occurs in the piezoelectric pump  211  and an emergency situation may occur in which the pressure in the fluid bag  203  is prevented from being reduced. Thus, in response to the operation of the emergency stop button, the blood pressure monitor  200  immediately discontinues the blood pressure measurement and causes the fluid in the fluid bag  203  to be discharged. Thus, the safety of the blood pressure measurement can be ensured. 
     [Step S 309 ] 
     On the other hand, as described above, the CPU  322  of the information processing device  300  determines, in step S 309  described above, whether the measurement start condition has deviated. For example, in a case where the difference between the initial angle and the current angle of the display screen  316  is within the range of a predetermined angle, for example the range of ±90 degrees, the CPU  322  determines that the measurement start condition has deviated. In a case where the measurement start condition is determined to have deviated (step S 309 , YES), the CPU  322  proceeds the processing to step S 314 . 
     [Step S 314 ] 
     In a case where in step S 309  described above, the measurement start condition is determined to have deviated (step S 309 , YES), the CPU  322  transmits a measurement stop command to the blood pressure monitor  200  through the communication interface  305 . 
     [Step S 315 ] 
     The CPU  322  then waits for a certain period of time, e.g., for the time required for normal blood pressure measurement. 
     [Step S 209 ] 
     The CPU  216  of the blood pressure monitor  200  determines, in step S 209  described above, whether the measurement stop command has been received from the information processing device  300 , as described above. For example, in a case where the measurement stop command is determined to have been received from the information processing device  300  based on the result of reception by the communication interface  209  that communicates with the information processing device  300  (step S 209 , YES), the CPU  216  advances the processing to step S 218 . 
     [Step S 218 ] 
     In step S 209  above, in a case where the measurement stop command is determined to have been received from the information processing device  300  (step S 209 , YES), the CPU  216  opens the valve  212  via the valve drive circuit  207  and evacuates the air in the fluid bag  203  of the cuff  202 . 
     [Step S 316 ] 
     After waiting for a certain period of time in step S 315  described above, the CPU  322  of the information processing device  300  determines whether the blood pressure value has been received from the blood pressure monitor  200  through the communication interface  305  or not. In a case where the blood pressure value is determined not to have been received (step S 316 , NO), the CPU  322  returns the processing to step S 302  described above. 
     In this way, when the measurement start condition deviates on the information processing device  300  side while the blood pressure monitor  200  is being pressurized, the pressure in the fluid bag  203  is not sufficient yet to enable the blood pressure to be measured using the blood pressure monitor  200 . Thus, the blood pressure measurement is discontinued. In a case where the blood pressure measurement is performed again, the processing may be repeated starting at step S 202  and at step S 302 . 
     [Step S 212 ] 
     As described above, the CPU  216  of the blood pressure monitor  200  determines, in step S 212  described above, whether the measurement stop command has been received from the information processing device  300  or not. For example, in a case where the measurement stop command is determined to have been received from the information processing device  300  based on the result of reception by the communication interface  209  that communicates with the information processing device  300  (step S 212 , YES), the CPU  216  advances the processing to step S 217 . 
     [Step S 217 ] 
     In step S 212  described above, in a case where the measurement stop command is determined to have been received from the information processing device  300  (step S 212 , YES), the CPU  216  determines whether compression at or above a predetermined pressure has continued for a certain period of time, for example, several seconds. For example, the CPU  216  makes this determination based on the back pressure detected by the pressure sensor  210  and indicated by a frequency signal input from the oscillation circuit  205 . The several seconds are illustrative and no such limitation is intended. In a case where the compression is determined not to have continued for the certain period of time (step S 217 , NO), the CPU  216  advances the processing to step S 213  described above. In a case where the compression is determined to have continued for the certain period of time (step S 217 , YES), the CPU  216  advances the processing to step S 218  described above. 
     [Step S 218 ] 
     In step S 217  described above, in a case where the compression is determined to have continued for the certain period of time (step S 217 , YES), the CPU  216  opens the valve  212  via the valve drive circuit  207  and evacuates the air in the fluid bag  203  of the cuff  202 . 
     In this way, when the measurement start condition deviates on the information processing device  300  side, in a case where the compression has continued at the blood pressure monitor  200  for the certain period of time, the CPU  216  of the blood pressure monitor  200  determines that the act of the deviation has been intentionally carried out by the subject corresponding to the operator of the information processing device  300  instead of operating the emergency stop button of the blood pressure monitor  200 . Thus, the CPU  216  immediately discontinues the blood pressure measurement and causes the fluid in the fluid bag  203  to be discharged. Thus, the safety of the blood pressure measurement can be ensured. 
     [Steps S 213  to S 216 ] 
     In contrast, in step S 217  described above, in a case where the compression is determined not to have continued for the certain period of time (step S 217 , NO), the CPU  216  advances the processing to step S 213  and executes the processing in steps S 213  to S 216  described above. Specifically, once the blood pressure value is calculated and determined, the blood pressure value calculated is transmitted to the information processing device  300  through the communication interface  209 , and the valve  212  is opened via the valve drive circuit  207  to evacuate the air in the fluid bag  203  of the cuff  202 . 
     [Step S 316 ] 
     After waiting for a certain period of time in step S 315  described above, the CPU  322  of the information processing device  300  determines whether the blood pressure value has been received from the blood pressure monitor  200  through the communication interface  305  or not. In a case where the blood pressure value is determined not to have been received (step S 316 , NO), the CPU  322  returns the processing to step S 302  described above. In a case where that the blood pressure value has been received (step S 316 , YES), the CPU  322  advances the processing to step S 311  above. 
     [Steps S 311  to S 313 ] 
     In step S 316  described above, in a case where the blood pressure value is determined to have been received (step S 316 , YES), the CPU  322  proceeds to step S 311  described above, and executes the processing in steps S 311  to S 313  described above. In other words, after the blood pressure value received is saved in the storage unit  302 , the end of the measurement is notified, and the measurement result is displayed on the display screen  316 . 
     In this way, when the measurement start condition deviates on the information processing device  300  side, in a case where the compression has not continued at the blood pressure monitor  200  for the certain period of time, the CPU  216  of the blood pressure monitor  200  can determine that the act of the deviation has been inadvertently carried out by the subject corresponding to the operator of the information processing device  300 , and continue the blood pressure measurement. 
     &lt;1-3&gt; Effect 
     According to the first embodiment described above, the blood pressure monitor  200  is caused to start the blood pressure measurement on condition that the subject corresponding to the operator of the information processing device  300  is prevented from viewing the display content of the display screen  316  of the display unit  315 . Thus, regardless of whatever content is caused to be displayed on the display screen  316  by an application program executed by the information processing device  300  in the background during the blood pressure measurement with the blood pressure monitor  200 , the subject is prevented from viewing the content. This prevents the subject from being upset by the display content or being subjected to a rise in blood pressure due to the display content. Consequently, even in a case where the information processing device  300  is used as a user interface for the blood pressure monitor  200 , accurate blood pressure measurement can be performed. 
     Note that, in the first embodiment, the measurement start condition is that the angle of the display screen  316  equals the measurement start angle at which the subject is prevented from viewing the display screen  316 , and this state is determined by the difference between the initial angle and the current angle of the display screen  316 . However, whether the angle of the display screen  316  equals the measurement start angle or not is not limited to this. For example, the determination may be made only by the current angle of the display screen  316 , that is, the direction in which the display screen  316  faces. For example, the situation in which the subject measures the blood pressure while lying down is exceptional, and thus the display screen  316  is unlikely to face in the gravitational direction during the blood pressure measurement. Thus, the measurement start angle may correspond to the state where the display screen  316  is at the angle at which the display screen  316  approximately faces the gravitational direction. 
     &lt;1-4&gt; Modified Examples 
     The measurement start conditions other than the measurement start angle will be described below as modified examples. 
     1-4-1 
       FIG. 8  is a flowchart illustrating an example of a processing procedure of measurement start determination processing in a first modified example of the first embodiment. 
     [Steps S 303 B to S 303 G] 
     In the first modified example, when the measurement start determination processing is started, the CPU  322  executes the processing in steps S 303 B to S 303 G described above without acquiring the initial angle of the display screen as in step S 303 A of the first embodiment. 
     [Step S 303 . 1 ] 
     In step S 303 D described above, in a case where the measurement preparation completion notification is determined to have been received from the blood pressure monitor  200  (step S 303 D, YES), the CPU  322  detects the brightness of the display screen  316 . For example, the CPU  322  detects the illuminance of the information processing device  300 , that is, the display screen  316 , in other words, brightness attributed to ambient light, based on the detection signal from the illuminance sensor  319  acquired via the input/output interface  308 . Alternatively, the CPU  322  can acquire an image from the front camera  311  via the image processing circuit  303 , and detect the brightness (illuminance) of the display screen  316  based on luminance information regarding the entire image. The brightness detected is stored in the RAM  323  or the storage unit  302 . 
     [Step S 303 K] 
     Then, the CPU  322  determines whether the brightness (illuminance) of the display screen  316  stored in the RAM  323  or the storage unit  302  is equal to or less than the predetermined measurement start brightness (illuminance) or not. The predetermined measurement start brightness (illuminance) is set to a brightness obtained when the display screen  316  is covered. This predetermined measurement start brightness (illuminance) is stored in the storage unit  302  in advance as a part of the blood pressure measurement application program. In a case where the brightness (illuminance) of the display screen  316  is not equal to or less than the predetermined measurement start brightness (illuminance) (step S 303 K, NO), the CPU  322  returns the processing to step S 303 J. In a case where the brightness (illuminance) of the display screen  316  is equal to or less than the predetermined measurement start brightness (illuminance) (step S 303 K, YES), the CPU  322  determines that the measurement start condition is satisfied, ends the measurement start determination process, and advances the processing to step S 304 . Thus, when the display screen  38  is covered, as described above in the application example, the CPU  322  can perform the processing of the determination unit  41  determining that the measurement start condition is satisfied. 
     In this way, the measurement start condition may be that the display screen  316  is covered. For example, in a case where the information processing device  300  is placed in a notebook type cover, closing the cover covers the display screen  316  to prevent the subject from viewing the display screen  316 . When the information processing device  300  is laid face down on a desk or the like, the display screen  316  is covered by a top plate of the desk. In a case where the measurement start condition is that the display screen  316  is covered, prevention of the subject from viewing the display content of the display screen  316  can be easily determined. 
     &lt;1-4-2&gt; Second Modified Example 
       FIG. 9  is a flowchart illustrating an example of a processing procedure of measurement start determination processing in a second modified example of the first embodiment. 
     [Step S 303 L] 
     In the second modified example, when the measurement start determination processing is started, the CPU  322  first captures an image using the front camera  311 , and stores the captured image in the RAM  323  or the storage unit  302  via the image processing circuit  303 . 
     [Step S 303 M] 
     Then, the CPU  322  performs known face detection processing on the image from the front camera  311  stored in the RAM  323  or the storage unit  302 . The program for the face detection processing may be stored in the storage unit  302  in advance as a part of the blood pressure measurement application program, or another application program may be utilized that is stored in the storage unit  302  for auto focus processing of the camera or face image processing, for example. 
     [Step S 303 N] 
     Then, the CPU  322  determines whether a face is detected in the image from the front camera  311  through the face detection processing in step S 303 M described above. In a case where a face is determined to have been detected (step S 303 N, YES), the CPU  322  advances the processing to step S 303 B described above. In a case where no face is determined to have been detected (step S 303 N, NO), the CPU  322  advances the processing to step S 303 F described above. 
     [Steps S 303 B to  5303 G] 
     Steps S 303 B to  5303 G are as described above in the first embodiment. However, in a case where in step S 303 N, no face is determined to have been detected (step S 303 N, NO) and where the processing proceeds to step S 303 F, transmission of the end of the inquiry in step S 303 G described above may be skipped. 
     [Step S 3030 ] 
     In step S 303 D described above, in a case where the measurement preparation completion notification is determined to have been received from the blood pressure monitor  200  (step S 303 D, YES), the CPU  322  captures an image again using the front camera  311 . The image from the front camera  311  is stored in the RAM  323  or storage unit  302  via the image processing circuit  303 . 
     [Step S 303 P] 
     Then, the CPU  322  performs known line-of-sight detection processing on the image from the front camera  311  stored in the RAM  323  or storage unit  302 . The program for the line-of-sight detection processing may be stored in the storage unit  302  in advance as a part of the blood pressure measurement application program, or another application program may be utilized that is stored in the storage unit  302  for character movement or character capturing in a game application program or key selection for a software keyboard based on the line of sight, for example. 
     [Step S 303 Q] 
     Then, the CPU  322  determines, through the face detection processing in step S 303 P, whether, in the image from the front camera  311 , the line of sight is directed toward the display screen  316 . Here, the position of the front camera  311  with respect to the display screen  316  is stored in advance in the ROM  324  or the storage unit  302 . Thus, the CPU  322  can easily determine whether the line of sight detected is directed toward the display screen  316 . In a case where the line of sight is determined to be directed toward the display screen  316  (step S 303 Q, YES), the CPU  322  returns the processing to step S 3030 . In a case where the line of sight is determined to be away from the display screen  316  (step S 303 Q, NO), the CPU  322  determines that the measurement start condition is satisfied, ends the measurement start determination processing, and advances the processing to step S 304 . Thus, the CPU  322  can execute the processing of the determination unit  41  in which the measurement start condition is determined to be satisfied when the line of sight of the operator is away from the display screen  38 , as described above in the application example. 
     In this way, the measurement start condition may be that the line of sight of the operator corresponding to the subject is away from the display screen  316 . When the operator performs the start operation, the operator views the display screen  316 . Thus, for example, in a case where the line of sight of the operator is detected by a known line-of-sight detection technique utilizing the front camera  311  and where the line of sight detected is away from the display screen, the operator can be determined to be prevented from viewing the display content of the display screen  316 . Thus, in the second modified example, the measurement start condition is that the line of sight of the operator is away from the display screen  316 . This allows the subject to be easily determined to be prevented from viewing the display content of the display screen  316 . 
     &lt;1-4-3&gt; Third Modified Example 
       FIG. 10  is a flowchart illustrating an example of a processing procedure of measurement start determination processing in a third modified example of the first embodiment. 
     [Steps S 303 B to S 303 G] 
     In the third modified example, when the measurement start determination processing is started, the CPU  322  performs the processing in steps S 303 B to S 303 G described above without acquiring the initial angle of the display screen as in step S 303 A of the first embodiment. 
     [Step S 303 R] 
     In step S 303 D described above, in a case where the measurement preparation completion notification is determined to have been received from the blood pressure monitor  200  (step S 303 D, YES), the CPU  322  captures an image using the rear camera  312 . The image from the rear camera  312  is stored in the RAM  323  or the storage unit  302  via the image processing circuit  303 . 
     [Step S 303 S] 
     Then, the CPU  322  performs known feature detection processing on the image from the rear camera  312  stored in the RAM  323  or the storage unit  302 . The feature detection processing is, for example, processing in which edge detection or the like is performed on the image and in which the shapes of objects included in the image, characters, and the like are detected. The program for the feature detection processing may be stored in the storage unit  302  in advance as a part of the blood pressure measurement application program, or another application program may be utilized that is stored in the storage unit  302 . The features detected are stored in the RAM  323  or the storage unit  302 . 
     [Step S 303 T] 
     Subsequently, the CPU  322  performs feature matching processing. This processing matches features stored in the RAM  323  or the storage unit  302  with feature information such as the shape of the blood pressure monitor  200  stored in advance in the storage unit  302  as a part of the blood pressure measurement application program, the logo of the product name, a model number string, and the like. For example, the storage unit  302  stores feature information regarding a plurality of types of blood pressure monitors  200 . The information may be optionally downloadable by the wireless communication interface  309  from an external device such as a server device via the communication network NW (Internet). When actual matching is performed, the processing time may be shortened by matching the features only with feature information corresponding to the blood pressure monitor  200  with which communication is established in step S 301 , from among feature information regarding the plurality of types of blood pressure monitors  200 . 
     [Step S 303 U] 
     Then, based on the results of the feature matching processing in step S 303 T described above, the CPU  322  determines whether the image from the rear camera  312  contains an image of the blood pressure monitor  200  with which communication is established in step S 301 . In a case where no image of the blood pressure monitor  200  with which communication is established is determined to be present (step S 303 T, NO), the CPU  322  returns the processing to step S 303 R described above. In a case where an image of the blood pressure monitor  200  with which communication is established is determined to be present (step S 303 T, YES), the CPU  322  ends the measurement start determination processing, and advances the processing to step S 304  described above. Thus, when the operation unit  33  receives the start operation, the CPU  322  can perform the processing of the determination unit  41  in which the measurement start condition is determined to be satisfied in a case where the blood pressure monitor  2  is present opposite to the display screen  38  with respect to the information processing device  3 , as described above in the application example. 
     In this way, the measurement start condition may be that the blood pressure monitor  200  is present at the rear surface, which is opposite to the display screen  316 . In a case where the operator operating the information processing device  300  differs from the subject of the blood pressure, the positional relationship between the subject and the information processing device  300  varies, and it is difficult to determine which orientation of the display screen  316  prevents the subject from viewing the display content of the display screen  316 . However, at least in a case where the blood pressure monitor  200  is present on the rear surface side of the information processing device  300  when the start operation is performed, the subject with the blood pressure monitor  200  is reliably located opposite to the display screen  316 , that is, the subject is prevented from viewing the display screen  316 . Thus, in the third modified example, the rear camera  312  is utilized to confirm the presence of the blood pressure monitor  200 , and the measurement start condition is that the blood pressure monitor  200  is present. This enables easy determination that the subject is prevented from viewing the display content of the display screen  316 . 
     &lt;1-4-4&gt; Fourth Modified Example 
       FIG. 11A  is a flowchart illustrating an example of a processing procedure of measurement start determination processing in a fourth modified example of the first embodiment. 
     [Steps S 303 B to S 303 G] 
     In the fourth modified example, when the measurement start determination processing is started, the CPU  322  performs the processing in steps S 303 B to S 303 G described above without acquiring the initial angle of the display screen as in step S 303 A of the first embodiment. 
     [Step S 303 V] 
     In step S 303 D described above, in a case where the measurement preparation completion notification is determined to have been received from the blood pressure monitor  200  (step S 303 D, YES), the CPU  322  causes the graphics controller  306  to reduce the brightness (luminance) of the display screen  316 . 
     [Step S 303 W] 
     Then, the CPU  322  determines whether the brightness (luminance) of the display screen  316  has been reduced to a predetermined brightness (luminance). The predetermined brightness (luminance) is set to a value at which the display content of the display screen  316  is invisible. For example, the predetermined brightness (luminance) is stored in the storage unit  302  in advance as a part of the blood pressure measurement application program. In a case where it is determined that the display screen  316  has not been reduced to a predetermined brightness (luminance) (step S 303 W, NO), the CPU  322  returns the processing to step S 303 V above. In a case wherein the brightness (luminance) of the display screen  316  is determined to have been reduced to a predetermined brightness (luminance) (step S 303 W, YES), the CPU  322  determines that the measurement start condition is satisfied, ends the measurement start determination processing, and advances the processing to step S 304 . Thus, the CPU  322  can execute the processing of the determination unit  41  in which, when the display screen  38  is dimmed enough to make the display content of the display screen  38  invisible, the measurement start condition is determined to be satisfied, as described above in the application example. 
     In this way, when the start operation is received, the display on the display screen  316  is gradually dimmed, and the measurement start condition may be that the display is dimmed enough to be invisible. Forcibly dimming the display screen  316  prevents the subject from viewing the display content of the display screen  316 . However, sudden erasure of the display screen may be mistaken for a failure or may surprise the subject, adversely affecting the blood pressure measurement. Thus, in the fourth modified example, the display on the display screen  316  is gradually dimmed. In a case where the measurement start condition is that the display screen  316  is dimmed enough to make the display content of the display screen  316  invisible, the subject can be easily determined to be prevented from viewing the display content of the display screen  316 . 
       FIG. 11B  is a flowchart illustrating another example of a processing procedure of measurement start determination processing in the fourth modified example of the first embodiment. 
     [Steps S 303 B to S 303 G] 
     When the measurement start determination processing is started, the CPU  322  performs the processing in steps S 303 B to S 303 G described above without acquiring the initial angle of the display screen as in step S 303 A of the first embodiment. 
     [Step S 303 X] 
     In step S 303 D described above, in a case where the measurement preparation completion notification is determined to have been received from the blood pressure monitor  200  (step S 303 D, YES), the CPU  322  causes the graphics controller  306  to activate any screen saver to display the screen saver on the display screen  316 . When the screen saver is displayed, the CPU  322  determines that the measurement start condition is satisfied, ends the measurement start determination processing, and advances the processing to step S 304 . Thus, the CPU  322  can perform the processing of the determination unit  41  in which, when the display on the display screen  38  changes to the state in which the subject is prevented from viewing the display content, the measurement start condition is determined to be satisfied, as described above in the application example. 
     In this way, when the start operation is received, the display on the display screen  316  may be switched to the screen saver. Displaying the screen saver on the display screen  316  ensures that the subject is prevented from viewing the display content of the display screen  316 . In this way, in a case where the measurement start condition is that the display on the display screen  316  changes to the state of a screen saver state in which display content of the display screen  316  is invisible, the subject can be easily determined to be prevented from viewing the display content of the display screen  316 . 
     &lt;2&gt; Second Embodiment 
     Now, a second embodiment will be described. 
     &lt;2-1&gt; Configuration and &lt;2-2&gt; Operation 
     A basic configuration and a basic operation of the biometric data measurement system according to the second embodiment are similar to the basic configuration and basic operation of the biometric data measurement system according to the first embodiment described above. Thus, descriptions of the matters described in the first embodiment are omitted, and items that can be easily inferred from the first embodiment described above are also omitted. 
     The present embodiment differs from the first embodiment described above in the processing procedure for the information processing device  300 .  FIG. 12  is a flowchart illustrating an example of a processing procedure for the information processing device  300  in accordance with a blood pressure measurement application program in the biometric data measurement system according to the second embodiment. For example, when the information processing device  300  is activated, the blood pressure measurement application program is executed in the background to start the processing procedure. 
     [Step S 351 ] 
     First, the CPU  322  of the information processing device  300  determines whether the current time clocked by a clock circuit  310  is a predetermined period of time before the measurement start date and time indicated by a measurement schedule stored in the storage unit  302 . The predetermined period of time is set to the time required for the subject to complete preparation of blood pressure measurement such as attachment of the cuff  202  of the blood pressure monitor  200 ; the set time is, for example, 3 minutes. The 3 minutes are illustrative and no such limitation is intended. For example, the predetermined period of time is stored in the storage unit  302  in advance as a part of the blood pressure measurement application program. In a case where the current time is determined not to be the predetermined period of time before the measurement start date and time or the measurement start date and time is determined not to be set (step S 351 , NO), the CPU  322  advances the processing to step S 352 . In a case where the current time is determined to be the predetermined period of time before the measurement start date and time (step S 351 , YES), the CPU  322  advances the processing to step S 358 . 
     [Step S 352 ] 
     In step S 351  described above, in a case where the current time is determined not to be the predetermined period of time before the measurement start date and time or the measurement start date and time is determined not to be set (step S 351 , NO), the CPU  322  determines whether the operator has performed a display instruction operation for an initial screen of the blood pressure measurement application program. The CPU  322  determines, for example, whether an activation icon for the blood pressure measurement application program on the display screen  316  has been operated or a specified operation of the running blood pressure measurement application program has been performed in a predetermined area such as a notification area in the display screen  316 , for example, based on coordinate data provided by the touch panel controller  307  in response to a touch operation of the touch panel  317 . In a case where the initial screen display instruction operation is determined not to have been performed (step S 352 , NO), the CPU  322  returns the processing to step S 351  described above. In a case where the initial screen display instruction operation is determined to have been performed (step S 352 , YES), the CPU  322  advances the processing to step S 353 . 
     [Step S 353 ] 
     In step S 352  described above, in a case where the initial screen display instruction operation is determined to have been performed (step S 352 , YES), the CPU  322  displays, on the display screen  316  via the graphics controller  306 , the initial screen of the blood pressure measurement application program including the icon  38 A for instructing the start of the blood pressure measurement. 
     [Step S 354 ] 
     Subsequently, the CPU  322  determines whether the start operation for the blood pressure measurement has been performed by the operator. For example, the CPU  322  determines, based on touch coordinates input from touch panel controller  307 , whether the location on the touch panel  317  corresponding to the icon  38 A for instructing the start of blood pressure measurement of touch panel  317  has been touched. In a case where the blood pressure measurement start operation is determined not to have been performed (step S 354 , NO), the CPU  322  advances the processing to step S 355 . In a case where the blood pressure measurement start operation is determined to have been performed (step S 354 , YES), the CPU  322  advances the processing to step S 356 . 
     [Step S 355 ] 
     In step S 354  described above, in a case where the blood pressure measurement start operation is determined not to have been performed (step S 354 , NO), the CPU  322  determines whether any other operation has been performed in the initial screen. In a case where no other operation is determined to have been performed (step S 355 , NO), the CPU  322  returns the processing to step S 354  described above. That is, in steps S 354  and S 355 , the CPU  322  waits for an operation from the operator. In a case where any other operation is determined to have been performed (step S 355 , YES), the CPU  322  advances the processing to step S 357 . 
     [Step S 356 ] 
     In step S 354  described above, in a case where the blood pressure measurement start operation is determined to have been performed (step S 354 , YES), the CPU  322  establishes near field communication with the blood pressure monitor  200  through the communication interface  305 . Subsequently, the CPU  322  advances the processing to step S 303  as described in the first embodiment. 
     [Step S 357 ] 
     In step S 355  described above, in a case where any other operation is determined to have been performed (step S 355 , YES), the CPU  322  executes other processing in accordance with the operation. Examples of the other processing may include, for example, setting of a measurement schedule such as measurement of the blood pressure at 7 o&#39;clock every morning, instruction to end display of the initial screen, instruction to end or prohibit of background execution of the blood pressure measurement application program, and the like. After the other processing ends, the CPU  322  returns the processing to step S 351  described above. 
     [Step S 358 ] 
     On the other hand, in step S 351  described above, in a case where the current time is the predetermined measurement start time before the measurement start date and time (step S 351 , YES), the CPU  322  outputs a measurement start time close-in message through the display screen  316  and/or the speaker  314 . For example, the CPU  322  causes the graphics controller  306  to display the characters of a measurement start time close-in message on the display screen  316  and causes the sound processing unit  304  to emit the voice of a measurement start time close-in message through the speaker  314 . For example, the content of the measurement start time close-in message is stored in the storage unit  302  in advance as a part of the blood pressure measurement application program. Note that even in a case where the information processing device  300  is in a sleep state, that is, even in a case where the operator is not using the information processing device  300 , the measurement start time close-in message is output to notify the operator corresponding to the subject that the blood pressure measurement date and time closes in. Thus, the CPU  322  can perform the processing of the notification unit  43  as described above in the application example. 
     [Step S 359 ] 
     Subsequently, the CPU  322  causes the graphics controller  306  to reduce the brightness (luminance) of the display screen  316 . 
     [Step S 360 ] 
     Then, the CPU  322  determines whether any operation has been performed by the operator. In a case where any operation is determined to have been performed (step S 360 , YES), the CPU  322  advances the processing to step S 353  described above. In a case where no operation is determined to have been performed (step S 360 , NO), the CPU  322  advances the processing to step S 361 . 
     [Step S 361 ] 
     In step S 360  described above, in a case where no operation is determined to have been operated (step S 360 , NO), the CPU  322  determines whether or not the current time clocked by the clock circuit  310  is past the measurement start date and time indicated by the measurement schedule stored in the storage unit  302 . In a case where the current time is determined to be past the measurement start date and time (step S 361 , YES), the CPU  322  advances the processing to step S 362 . In a case where the current time is determined not to be past the measurement start date and time (step S 361 , NO), the CPU  322  returns the processing to step S 359  described above. In this way, the display on the display screen  316  is gradually dimmed 
     Even in a case where the operator is executing an application program other than the blood pressure measurement application program, the processing in steps S 359  to S 361  inhibits the display and operation of this application program and divert the subject to the blood pressure measurement. However, in a case where the display is dimmed enough to make the display content completely unrecognizable, the operator may misinterpret the information processing device  300  as being in the sleep state. Thus, desirably, the display is dimmed such that the display content is recognizable to some degree to remind the operator that the blood pressure measurement date and time closes in. Then, when the operator performs some operation, regardless of the content of the operation, the processing can be shifted to step S 353  described above to display the initial screen of the blood pressure measurement application program. 
     [Step S 362 ] 
     In step S 361  described above, in a case where the current time is determined to be or be past the measurement start date and time (step S 361 , YES), the CPU  322  performs processing for establishing near field communication with the blood pressure monitor  200  through the communication interface  305 . 
     [Step S 363 ] 
     Subsequently, the CPU  322  determines whether communication with the blood pressure monitor  200  has successfully been established. In a case where a long time is required for the subject corresponding to the operator to power on the blood pressure monitor  200 , the communication establishment processing in step S 362  ends with no communication established. In a case where communication with the blood pressure monitor  200  is determined to have successfully been established (step S 363 , YES), the CPU  322  advances the processing to step S 365 . In a case where communication is determined not to have successfully been established (step S 363 , NO), the CPU  322  advances the processing to step S 364 . 
     [Step S 364 ] 
     In step S 363  described above, in a case where communication with the blood pressure monitor  200  is determined not to have successfully been established (step S 363 , NO), the CPU  322  determines whether a certain amount of time has elapsed. The certain amount of time is set shorter than the predetermined period of time in step S 351 , and set to, for example, 1 minute. The 1 minute is illustrative and not such limitation is intended. For example, the certain amount of time is stored in the storage unit  302  in advance as a part of the blood pressure measurement application program. In a case where the certain amount of time is determined not to have elapsed (step S 364 , NO), the CPU  322  returns the processing to step S 362  described above. In a case where the certain amount of time is determined to have elapsed (step S 364 , YES), the CPU  322  advances the processing to step S 366 . 
     [Step S 365 ] 
     In step S 363  described above, communication with blood pressure monitor  200  is determined to have successfully been established (step S 363 , YES), the CPU  322  causes the graphics controller  306  to recover the brightness (luminance) of display screen  316  to the original brightness. Subsequently, the CPU  322  advances the processing to step S 303  as described in the first embodiment. Specifically, establishment of communication with the blood pressure monitor  200  means that the subject has prepared for the blood pressure measurement. Thus, in this case, whether the measurement start operation has been performed or not is not determined, and processing is executed that is similar to the processing performed in a case where the measurement start operation has been executed. 
     [Step S 366 ] 
     In step S 364  described above, in a case where a certain period of time is determined to have elapsed with no communication with the blood pressure monitor  200  established (step S 364 , YES), the CPU  322  transitions the information processing device  300  into the sleep state. The CPU  322  then returns the processing to step S 351  described above. 
     &lt;2-3&gt; Effect 
     According to the second embodiment described above, in addition to the blood pressure measurement at any point in time instructed by the operator as in the first embodiment described above, blood pressure measurement according to the measurement schedule specified by the subject in advance may be performed. 
     In other words, in a case where a preset date and time closes in, for example, the CPU  322  outputs a measurement start time close-in message, and then gradually dims the display on the display screen  316 . Then, in a case where communication with the blood pressure monitor  200  is established within a certain period of time from the measurement start date and time, the display is recovered to the original state, and a determination of whether the measurement start condition is satisfied is started. In this way, notifying the subject that the measurement start date closes in can prompt the subject to measure the blood pressure at the preset date and time, and prevent the subject from forgetting to measure the blood pressure. Moreover, the display is gradually dimmed after the measurement start time close-in message is output, and thus even in a case where the subject is operating any other application program on the information processing device  300 , the operation is made difficult, allowing the subject to be diverted to the blood pressure measurement. 
     Note that, rather than outputting the measurement start time close-in message when the preset date and time closes in, a measurement start time arrival message may be output when the current time is or is past the preset date and time. In other words, instead of using, as a trigger, the time the predetermined period of time before the measurement start date, the measurement start date and time may be used as a trigger. In this case, the determination in step S 361  may be omitted. 
     Note that the embodiments have been described but that the present invention is not limited to the embodiments described above, and can be embodied by modifying the components in an implementation stage without departing from the gist thereof. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment described above. For example, some constituent elements may be omitted from the entire constituent elements shown in the embodiment. Furthermore, the constituent elements of different embodiments may be combined appropriately. 
     For example, the embodiments have been described taking, as an example, an electronic blood pressure monitor using a technique (oscillometric method) for compressing the blood vessel to detect a pulse wave. However, the present invention can be applied to, for example, blood pressure monitors using any techniques, such as a technique for continuously measuring the blood pressure of a measurer based on a pulse transit time (PTT), a technique for continuously measuring the blood pressure based on a pressure pulse wave (tonometry method), and a technique for detecting a pulse wave using a light emitting element. In a blood pressure monitor that does not use the oscillometric method, the measurement may be immediately discontinued, for example, when an emergency stop instruction is input or when a measurement stop command is received from the information processing device. The inquiry of whether the measurement preparation is complete can be omitted, the inquiry being made to the blood pressure monitor from the information processing device. 
     The whole or part of the embodiments described above can be described as, but not limited to, the following supplementary notes. 
     (Supplementary Note 1) 
     A method for causing a biometric data measurement device to measure biometric data, the method being executed by an information processing device including a processor, a memory, a communication unit connecting to a communication network, a display unit including a display screen displaying various pieces of information, a connection unit connecting to another device wirelessly or by wire, and an operation unit receiving a user operation, the method including the steps of: 
     the processor determining whether a measurement start condition is satisfied when the operation unit receives a measurement start operation for the biometric data measuring device, and
 
the processor transmitting a measurement start command to the biometric data measurement device via the connection unit in a case where the measurement start condition is satisfied,
 
wherein the measurement start condition includes prevention of the subject of the biometric data from viewing a display content of the display screen.
 
     (Supplementary Note 2) 
     The biometric data measurement system according to claim  1  or  2 , wherein the information processing apparatus further includes a speaker generating sound, and the control unit controls to output, through the speaker, music assisting in maintaining a resting state of the subject during measurement performed by the biometric data measurement system. 
     (Supplementary Note 3) 
     The biometric data measurement system according to claim  2 , wherein the measurement start angle is an angle exceeding a range of ±90 degrees with respect to the angle of the display screen when the operation unit receives the start operation. 
     (Supplementary Note 4) 
     The biometric data measurement system according to claim  10 , wherein, when the control unit gradually dims display on the display screen, in a case where the control unit is connected to the biometric data measurement device within a certain period of time, the control unit recovers the display on the display screen to an original state and then starts to determine whether the measurement start condition is satisfied. 
     (Supplementary Note 5) 
     The biometric data measurement system according to any one of claims  1  to  14 , wherein the control unit erases the display screen when the measurement start condition is satisfied. 
     (Supplementary Note 6) 
     A biometric data measurement program causing a processor to function as the control unit included in the information processing device according to any one of claims  1  to  15 . 
     REFERENCE SIGNS LIST 
     
         
           1  Biometric data measurement system 
           2 ,  200  Blood pressure monitor 
           3 ,  300  Information processing device 
           21 ,  201  Blood pressure monitor body 
           22 ,  202  Cuff 
           23  Blood pressure measurement unit 
           24 ,  203  Fluid bag 
           25  Detection unit 
           26  Blood pressure monitor connection unit 
           27  Blood pressure monitor control unit 
           28  Emergency stop button 
           31  Communication unit 
           32  Connection unit 
           33  Operation unit 
           33 A Operation button 
           33 B Touch sensor 
           34 ,  315  Display unit 
           35  Sensor 
           35 A,  311  Front camera 
           35 B,  319  Illuminance sensor 
           36  Notification unit 
           37 ,  204 ,  301  Control unit 
           38 ,  316  Display screen 
           38 A Icon 
           39 ,  314  Speaker 
           40  Vibration member 
           41  Determination unit 
           42  Operation guidance unit 
           43  Notification unit 
           44  Inquiry unit 
           205  Oscillation circuit 
           206  Pump drive circuit 
           207  Valve drive circuit 
           208 ,  308  Input/output interface 
           209 ,  305  Communication interface 
           210  Pressure sensor 
           211  Piezoelectric pump 
           212  Valve 
           213  Tubing 
           214  Cuff wrapping state detection unit 
           215  Power supply switch 
           216 ,  322  CPU 
           217 ,  323  RAM 
           218 ,  324  ROM 
           302  Storage unit 
           303  Image processing circuit 
           304  Sound processing unit 
           306  Graphics controller 
           307  Touch panel controller 
           309  Wireless communication interface 
           310  Clock circuit 
           312  Rear camera 
           313  Microphone 
           317  Touch panel 
           318  Acceleration sensor 
           320  Operation member 
           321  Vibrator