Patent Publication Number: US-2021177274-A1

Title: Measurement device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is the U.S. national stage application filed pursuant to 35 U.S.C. 365(c) and 120 as a continuation of International Patent Application No. PCT/JP2019/029024, filed Jul. 24, 2019, which application claims priority from Japanese Patent Application No. 2018-154490, filed Aug. 21, 2018, which applications are incorporated herein by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     Aspects of the present invention relate to, for example, a measurement device configured to measure an electrocardiogram reading and blood pressure of a user. 
     BACKGROUND ART 
     For example, for diagnosis or treatment of a cardiovascular disease, a patient may be required by a physician to periodically measure an electrocardiogram readings and blood pressure at home (for example, after wake-up and before bedtime on a daily basis). It is important to remember to measure an electrocardiogram reading and blood pressure, and a patient uses a schedule management application installed in a user terminal device such as a smartphone to output an alert at time for measurement. Additionally, there is a measurement device such as a blood pressure monitor including an alert function to output an alert at time for measurement (see Patent Document 1, for example). 
     CITATION LIST 
     Patent Literature 
     Patent Document 1: JP 2006-26210 A 
     SUMMARY OF INVENTION 
     Technical Problem 
     In the case described above, despite measuring one of an electrocardiogram reading and blood pressure in response to the alert, a patient may forget to measure either electrocardiogram readings or blood pressure. 
     In view of the above-described circumstances, an object of the present invention is to provide a measurement device that can prevent a user from forgetting, after measuring one of an electrocardiogram reading and blood pressure, to measure the other of an electrocardiogram reading and blood pressure. 
     Solution to Problem 
     The present invention adopts the following configurations to solve the above-described problems. 
     A measurement device according to an aspect includes an electrocardiogram measurement unit configured to measure an electrocardiogram reading of a user, a blood pressure measurement unit configured to measure blood pressure of the user, a measurement end detection unit configured to detect an end of electrocardiogram measurement by the electrocardiogram measurement unit, a notification unit configured to output a message notifying that the blood pressure measurement is to be performed, in response to the measurement end detection unit that has detected the end of the electrocardiogram measurement, and a blood pressure measurement control unit configured to start blood pressure measurement by the blood pressure measurement unit in response to the measurement end detection unit that has detected the end of the electrocardiogram measurement. 
     According to the above-described configuration, the blood pressure measurement starts after the end of the electrocardiogram measurement without the user instructing the start of the blood pressure measurement. Thus, the user can be prevented from forgetting to perform the blood pressure measurement after the electrocardiogram measurement. Further, the measurement device can independently measure both an electrocardiogram and blood pressure, and is thus highly convenient for the user. 
     In the aspect described above, the measurement device includes a notification unit configured to notify that the blood pressure measurement is to be performed, in response to the measurement end detection unit that has detected the end of the electrocardiogram measurement. 
     According to the above-described configuration, the user can recognize the start of the blood pressure measurement and prepare for the blood pressure measurement. For example, in response to the notification, the user takes posture appropriate for the blood pressure measurement. 
     In an aspect, the measurement device may further include a posture detection unit configured to detect that the user is in posture appropriate for the blood pressure measurement, and the blood pressure measurement control unit starts the blood pressure measurement in response to the measurement end detection unit that has detected the end of the electrocardiogram measurement and the posture detection unit that has detected that the user is in posture appropriate for the blood pressure measurement. 
     According to the above-described configuration, the blood pressure measurement can be performed while the user is in posture appropriate for the blood pressure measurement. As a result, a highly reliable blood pressure measurement value can be obtained. 
     In an aspect, the measurement device may further include an instruction unit configured to instruct the user to assume posture appropriate for the blood pressure measurement, when the posture detection unit does not detect that the user is in posture appropriate for the blood pressure measurement, before a predetermined period of time has elapsed since the end of the electrocardiogram measurement. 
     According to the above-described configuration, the user can more securely perform the blood pressure measurement in a state where the user is in posture appropriate for the blood pressure measurement. As a result, a highly reliable blood pressure measurement value can be obtained more securely. 
     A measurement device according to an aspect includes an electrocardiogram measurement unit configured to measure an electrocardiogram reading of a user, a blood pressure measurement unit configured to measure blood pressure of the user, a measurement end detection unit configured to detect an end of blood pressure measurement by the blood pressure measurement unit, a notification unit configured to output a message notifying that the electrocardiogram measurement is to be performed, in response to the measurement end detection unit that has detected the end of the blood pressure measurement, and an electrocardiogram measurement control unit configured to start electrocardiogram measurement by the electrocardiogram measurement unit in response to the measurement end detection unit that has detected the end of the blood pressure measurement. 
     According to the above-described configuration, the electrocardiogram measurement starts after the end of the blood pressure measurement, without the user instructing the start of the electrocardiogram measurement. Thus, the user can be prevented from forgetting to perform the electrocardiogram measurement after the blood pressure measurement. Further, the measurement device can independently measure both an electrocardiogram and blood pressure, and is thus highly convenient for the user. 
     In the aspect described above, the measurement device includes a notification unit configured to notify that the electrocardiogram measurement is to be performed, in response to the measurement end detection unit that has detected the end of the blood pressure measurement. 
     According to the above-described configuration, the user can recognize the start of the electrocardiogram measurement and prepare for the electrocardiogram measurement. For example, in response to the notification, the user brings a hand that is not attached to the measurement device into contact with an electrode for the electrocardiogram measurement. 
     In an aspect, the measurement device may further include an attachment member configured to be attached to the user, and the electrocardiogram measurement unit includes a first electrode provided in a surface of a side that comes into contact with the user of the attachment member, a second electrode provided in a surface of a side that does not come into contact with the user of the attachment member, and an electrocardiogram generation unit configured to generate the electrocardiogram based on a potential difference between the first electrode and the second electrode, and the measurement device further includes a contact detection unit configured to detect contact of the user with the second electrode, and an instruction unit configured to instruct the user to come into contact with the second electrode, when the contact detection unit does not detect the contact of the user with the second electrode, before a predetermined time period has elapsed since the end of the blood pressure measurement. 
     According to the above-described configuration, the electrocardiogram measurement can be performed more securely. 
     Advantageous Effects of Invention 
     According to the present invention, a measurement device that can prevent a user from forgetting, after measuring one of an electrocardiogram and blood pressure, to measure the other of an electrocardiogram and blood pressure. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a view illustrating a measurement device according to an embodiment. 
         FIG. 2  is a perspective view illustrating appearance of a measurement device according to a first embodiment. 
         FIG. 3  is a cross-sectional view of the measurement device according to the first embodiment. 
         FIG. 4  is a view illustrating a hardware configuration of a control system of the measurement device according to the first embodiment. 
         FIG. 5  is a view illustrating a software configuration of the measurement device according to the first embodiment. 
         FIG. 6  is a view illustrating posture appropriate for pressure measurement. 
         FIG. 7  is a flowchart illustrating a processing procedure of performing blood pressure measurement after electrocardiogram measurement according to the first embodiment. 
         FIG. 8  is a flowchart illustrating a processing procedure of blood pressure measurement by an oscillometric method according to the first embodiment. 
         FIG. 9  is a view illustrating relationship between cuff pressure and a pulse wave signal in blood pressure measurement by the oscillometric method. 
         FIG. 10  is a view illustrating a software configuration of a measurement device according to a second embodiment. 
         FIG. 11  is a flowchart illustrating a processing procedure of performing electrocardiogram measurement after blood pressure measurement according to the second embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, embodiments of the present invention will be described with reference to the drawings. 
     Application Example 
     With reference to  FIG. 1 , an example of a scene where the present invention is applied will be described.  FIG. 1  illustrates a measurement device  10  according to an embodiment. The measurement device  10  is a wearable device and is attached to the left wrist of a user in the example of  FIG. 1 . The measurement device  10  includes a belt portion  20 , an electrocardiogram measurement unit  30 , a blood pressure measurement unit  40 , a measurement end detection unit  50 , and a blood pressure measurement control unit  60 . 
     The belt portion  20  is a member wrapped around a left wrist  70  of the user and is used to attach the measurement device  10  to the left wrist  70  of the user. The belt portion  20  includes an inner circumferential surface and an outer circumferential surface  21 . The inner circumferential surface refers to a portion of a front surface of the belt portion  20  that faces the left wrist  70  of the user in a state where the measurement device  10  is attached to the left wrist  70  of the user. The outer circumferential surface  21  refers to a portion of the front surface of the belt portion  20  other than the inner circumferential surface. In other words, the inner circumferential surface is a surface of a side that comes into contact with the user in a state where the measurement device  10  is attached to the left wrist  70  of the user, and the outer circumferential surface  21  is a surface of a side that does not come into contact with the user in a state where the measurement device  10  is attached to the left wrist  70  of the user. The belt portion  20  is an example of an attachment member attached to the user. 
     The electrocardiogram measurement unit  30  is provided in the belt portion  20 , and measures an electrocardiogram of the user. The electrocardiogram is a waveform signal that represents electrical activity of a heart of the user. In the present embodiment, the electrocardiogram measurement unit  30  uses an induction method referred to as first induction. That is, the electrocardiogram measurement unit  30  measures an electrocardiogram based on a potential difference occurring between both upper limbs. The electrocardiogram measurement unit  30  includes an electrode  31 , an electrode  32 , and an electrocardiogram generation unit  33 . The electrode  31  is provided in the inner circumferential surface of the belt portion  20  and comes into contact with the left wrist  70  of the user in a state where the measurement device  10  is attached to the left wrist  70  of the user. The electrode  32  is provided in the outer circumferential surface  21  of the belt portion  20  and does not come into contact with the left wrist  70  of the user in a state where the measurement device  10  is attached to the left wrist  70  of the user. In measuring an electrocardiogram, the user touches the electrode  32  with a right hand (for example, an index finger of the right hand). Accordingly, a state where the electrode  31  is disposed in a left upper limb of the user and the electrode  32  is disposed in a right upper limb of the user is generated. The electrocardiogram generation unit  33  generates an electrocardiogram based on a potential difference between the electrode  31  and the electrode  32 . 
     The blood pressure measurement unit  40  is provided in the belt portion  20  and measures blood pressure of the user. The blood pressure measurement unit  40  includes a pressing cuff that presses the left wrist  70  based on supply of air, and performs blood pressure measurement based on the oscillometric method or the Korotkoff method. 
     The measurement end detection unit  50  detects the end of measurement by the electrocardiogram measurement unit  30 . For diagnosis or treatment of a cardiovascular disease, data of an electrocardiogram for a predetermined period of time (for example, 30 seconds) may be required. The measurement end detection unit  50  determines the end of the measurement by the electrocardiogram measurement unit  30  when data of an electrocardiogram for a predetermined period of time is acquired. In other words, the measurement end detection unit  50  determines the end of the measurement by the electrocardiogram measurement unit  30  when a predetermined period of time has elapsed since the contact of the right hand of the user with the electrode  32 . 
     The blood pressure measurement control unit  60  controls the blood pressure measurement unit  40 . The blood pressure measurement control unit  60  starts measurement by the blood pressure measurement unit  40  in response to the measurement end detection unit  50  that has detected the end of the measurement by the electrocardiogram measurement unit  30 . 
     In the measurement device  10  including the configuration described above, after electrocardiogram measurement, blood pressure measurement is performed without the user inputting, to the measurement device  10 , an instruction to measure blood pressure. Accordingly, the user is prevented from forgetting to measure blood pressure after electrocardiogram measurement. Further, the measurement device  10  can independently measure both an electrocardiogram and blood pressure, and is thus highly convenient for the user. 
     Note that the measurement device  10  may be configured to perform electrocardiogram measurement after blood pressure measurement. Additionally, the measurement device  10  may be configured such that operating modes can be switched among an operating mode in which blood pressure measurement is performed after electrocardiogram measurement, an operating mode in which electrocardiogram measurement is performed after blood pressure measurement, an operating mode in which electrocardiogram measurement is performed, and an operating mode in which blood pressure measurement is performed. 
     Hereinafter, a measurement device according to an embodiment will be described in detail. A first embodiment relates to a measurement device configured to perform blood pressure measurement after electrocardiogram measurement, and a second embodiment relates to a measurement device configured to perform electrocardiogram measurement after blood pressure measurement. 
     First Embodiment 
     Configuration Example 
     Hardware Configuration 
     An example of a hardware configuration of a measurement device  100  according to the first embodiment will be described with reference to  FIGS. 2 to 4 . 
       FIG. 2  is a perspective view illustrating appearance of the measurement device  100 . As illustrated in  FIG. 2 , the measurement device  100  is a wristwatch device. The measurement device  100  is designed to be attached to a left wrist of a user. The measurement device  100  includes a belt portion  120 , a display device  106 , an input device  107 , an electrode  131 , and an electrode  132 . The belt portion  120  includes a belt  121 , a body  123 , and a three fold buckle  124 . 
     The belt  121  refers to a band-like member wrapped around and attached to the left wrist of the user and may also be referred to as another name such as a “band.” The belt  121  includes an inner circumferential surface  121 A and an outer circumferential surface  121 B. The inner circumferential surface  121 A is a front surface that faces the left wrist of the user in a state where the measurement device  100  is attached to the user (hereinafter, simply referred to as an “attachment state”), and the outer circumferential surface  121 B is a front surface opposite to the inner circumferential surface  121 A. The width of the belt  121  is set to approximately 30 mm in this example. The width is a dimension in the width direction of the belt  121 . The width direction of the belt  121  corresponds to the longitudinal direction of the left wrist indicated by an arrow Y. 
     The body  123  is integrally molded at an end portion  121 E in the circumferential direction of the belt  121 . Note that the belt  121  and the body  123  may be formed separately, and the body  123  may be attached to the belt  121  by an engagement member (for example, a hinge). In this example, a portion of the belt  121  in which the body  123  is disposed is expected to be positioned in a surface of a back side of the left wrist in the attachment state. The body  123  is formed to be thin and compact not to interfere with daily activity of the user. In this example, the body  123  has a profile of a truncated quadrangular pyramid shape protruding outward from the belt  121 . 
     The display device  106  is provided in a top surface  123 A of the body  123 . The input device  107  is provided along a side surface  123 F of the body  123 . The display device  106  and the input device  107  will be described below. 
     A bottom surface  123 B of the body  123  is connected to the other end portion  121 F in the circumferential direction of the belt  121  by the buckle  124 . The buckle  124  includes a first plate-like member  125 , a second plate-like member  126 , a connecting rod  127 , a connecting rod  128 , and a fixing portion  129 . The second plate-like member  126  is disposed in an inner circumferential side with respect to the first plate-like member  125 . One end portion  125 E of the first plate-like member  25  is freely rotatably attached to the body  123  via the connecting rod  127  extending along the width direction of the belt  121 . The other end portion  125 F of the first plate-like member  125  is freely rotatably attached to one end portion  126 F of the second plate-like member  126  via the connecting rod  128  extending along the width direction of the belt  121 . The other end portion  126 E of the second plate-like member  126  is fixed to the end portion  121 F of the belt  121  by the fixing portion  129 . Note that an attachment position of the fixing portion  129  with respect to the circumferential direction of the belt  121  is variably set in advance in accordance with the circumferential length of the left wrist of the user. Accordingly, the belt  121  is generally constituted in a substantially annular shape, and the bottom surface  123 B of the body  123  and the end portion  121 F of the belt  121  can be opened and closed in a direction indicated by an arrow B by the buckle  124 . 
     The electrode  131  is provided in the inner circumferential surface  121 A of the belt  121  between the end portion  121 E and the end portion  121 F of the belt  121 . The electrode  131  has, for example, a plate-like shape or a sheet-like shape. In this example, the electrode  131  has a shape that is long in the circumferential direction of the belt  121 . Accordingly, the electrode  131  securely comes into contact with the left wrist of the user in the attachment state. Note that the electrode  131  may be disposed in an inner circumferential surface  126 A of the second plate-like member  126  of the buckle  124 . 
     The electrode  132  is provided in the top surface  123 A of the body  123 . Accordingly, the electrode  132  does not come into contact with the left wrist of the user in the attachment state. Note that the electrode  132  may be provided in the outer circumferential surface  121 B of the belt  121 . 
     When the measurement device  100  is attached to the left wrist of the user, the user passes a left hand through the belt  121  in a direction indicated by an arrow A, in a state where the buckle  124  is opened to increase the diameter of a ring of the belt  121 . In a state where the body  123  is positioned in the surface of the back side of the left wrist, the user closes and fixes the buckle  124 . In this way, the user attaches the measurement device  100  to the left wrist. 
       FIG. 3  illustrates a cross-section of the measurement device  100  in the attachment state. As illustrated in  FIG. 3 , the belt  121  includes a band-like body  122  and a pressing cuff  141  attached along an inner circumferential surface of the band-like body  122 . In this example, the band-like body  122  is formed of a plastic material, and has flexibility with respect to the thickness direction, and is substantially non-stretchable with respect to the circumferential direction. In this example, the pressing cuff  141  is constituted as a fluid bag by causing two stretchable polyurethane sheets to face each other in the thickness direction and welding circumferential edges of the two stretchable polyurethane sheets. The electrode  131  is disposed in an inner circumferential surface of the pressing cuff  141 . The inner circumferential surface of the pressing cuff  141  is the inner circumferential surface  121 A of the belt  121 . 
       FIG. 4  illustrates a hardware configuration of a control system of the measurement device  100 . As illustrated in  FIG. 4 , in addition to the display device  106 , the input device  107 , and the electrode  132 , the body  123  of the measurement device  100  is provided with a control unit  101 , a storage unit  105 , an acceleration sensor  108 , a speaker  109 , a communication interface  110 , a battery  111 , a signal processing circuit  133 , a pressure sensor  142 , a pump  143 , a valve  144 , an oscillation circuit  145 , a pump drive circuit  146 , and a valve drive circuit  147 . The electrode  131  and the pressure cuff  141  are provided in the belt  121 . 
     The control unit  101  includes a Central Processing Unit (CPU)  102 , a Random 
     Access Memory (RAM)  103 , a Read Only Memory (ROM)  104 , and the like and controls each component. For example, the storage unit  105  is an auxiliary storage device such as a semiconductor memory (for example, a flash memory), and non-transitorily stores a program executed by the control unit  101 , settings data necessary for executing the program, measurement data of an electrocardiogram, measurement data of blood pressure, and the like. A storage medium provided in the storage unit  105  is a medium that accumulates information such as a recorded program by an electrical, magnetic, optical, mechanical, or chemical action such that a computer, other devices, a machine, or the like can read the information such as the recorded program. Note that at least a portion or all of the program may be stored in the ROM  104 . 
     The display device  106  is controlled by the control unit  101  and displays information such as blood pressure measurement results. The display device  106  is an organic Electro-Luminescence (EL) display, for example. The organic EL display may also be referred to as an Organic Light Emitting Diode (OLED) display. Note that the display device  106  may be a display device of a different system, such as a liquid crystal display (LCD) device, for example. 
     The input device  107  enables the user to input an instruction to the measurement device  100 . The input device  107  receives an operation by the user, for example, an operation corresponding to an instruction to start measurement. The input device  107  includes, for example, a plurality of push buttons. Note that the input device  107  may be a touch panel provided on a screen of the display device  106 . 
     The acceleration sensor  108  is, for example, a triaxial acceleration sensor and outputs an acceleration signal representing acceleration in three directions orthogonal to one another. The speaker  109  is supplied with an audio signal from the control unit  101  and converts the audio signal into sound. 
     The communication interface  110  is an interface for communicating with an external device. The communication interface  110  includes, for example, a short-range wireless module such as a Bluetooth (trade name) module or a Bluetooth Low Energy (BLE) module and directly communicates with a terminal device (for example, a smartphone) possessed by the user. The communication interface  110  may include, instead of or in addition to the short-range wireless module, other wireless module such as a wireless Local Area Network (LAN) module. The communication interface  110  communicates with an external device via a communication network such as the Internet by using a wireless LAN module. Additionally, the communication unit  110  may include a terminal such as a micro Universal Serial Bus (USB) connector and may communicate with an external device via a cable such as a USB cable. 
     The battery  111  supplies power to each component housed in the body  123 . The battery  111  is a rechargeable battery, for example. 
     The signal processing circuit  133  includes an instrumentation amplifier  134 , a low pass filter (LPF)  135 , an amplifier  136 , and an analog-to-digital converter (ADC)  137 . The instrumentation amplifier  134  includes two input terminals, and the electrode  131  and the electrode  132  are respectively connected to the input terminals. The instrumentation amplifier  134  differentially amplifies potential of the electrode  131  and potential of the electrode  132 , and generates a potential difference signal in accordance with a potential difference between the electrode  131  and the electrode  132 . The instrumentation amplifier  134  is an example of a potential difference signal generation unit that generates a potential difference signal representing a potential difference between the electrode  131  and the electrode  132 . The potential difference signal is filtered by the LPF  135  and amplified by the amplifier  136  and converted to a digital signal by the ADC  137 . The LPF  135  is an example of a filter for removing noise incorporated in a potential difference signal. The control unit  101  acquires, as an electrocardiogram, a potential difference signal output from the signal processing circuit  133  by a time series. 
     The pump  143  and the valve  144  are connected to the pressing cuff  141  via a pipe  149 , and the pressure sensor  142  is connected to the pressing cuff  141  via a pipe  148 . Note that the pipes  148  and  149  may be a common single pipe. The pump  143  is, for example, a piezoelectric pump and supplies air as fluid to the pressing cuff  141  through the pipe  148  to increase pressure inside the pressing cuff  141 . The pump drive circuit  146  is controlled by the control unit  101  and drives the pump  143 . The valve drive circuit  147  is controlled by the control unit  101  and drives the valve  144 . In a state where the valve  144  is opened, the pressing cuff  141  is in communication with atmosphere. The valve  144  includes a function of a check valve and prevents air from flowing into the pressing cuff  141  through the valve  144 . 
     The pressure sensor  142  is, for example, a piezoresistive pressure sensor, detects pressure inside the pressing cuff  141  (hereinafter, also referred to as cuff pressure), and outputs an electrical signal representing the cuff pressure. The cuff pressure is, for example, pressure based on atmospheric pressure as a reference. The oscillation circuit  145  oscillates based on the electrical signal from the pressure sensor  142  and outputs, to the control unit  101 , a frequency signal having a frequency in accordance with the electrical signal. An output of the pressure sensor  142  is used to control pressure of the pressing cuff  141  and to calculate a blood pressure value (including systolic blood pressure (SBP) and diastolic blood pressure (DBP)) by the oscillometric method. 
     Note that, with respect to a specific hardware configuration of the measurement device  100 , a component can be omitted, replaced, or added as appropriate in accordance with embodiments. For example, the control unit  101  may include a plurality of processors. Additionally, instead of the acceleration sensor  108  or in addition to the acceleration sensor  108 , the measurement device  100  may include an angular velocity sensor. An output of the angular velocity sensor can be used to detect whether the user is in posture appropriate for blood pressure measurement. 
     Software Configuration 
     An example of a software configuration of the measurement device  100  will be described with reference to  FIG. 5 . In the example of  FIG. 5 , the measurement device  100  includes an input unit  151 , a display control unit  152 , an electrocardiogram measurement control unit  153 , an electrocardiogram acquisition unit  154 , a blood pressure measurement control unit  155 , a blood pressure value calculation unit  156 , a measurement end detection unit  157 , a posture detection unit  158 , a notification unit  159 , an instruction unit  160 , an electrocardiogram storage unit  171 , and a blood pressure value storage unit  172 . The control unit  101  of the measurement device  100  executes a program stored in the storage unit  105  to cause the input unit  151 , the display control unit  152 , the electrocardiogram measurement control unit  153 , the electrocardiogram acquisition unit  154 , the blood pressure measurement control unit  155 , the blood pressure value calculation unit  156 , the measurement end detection unit  157 , the posture detection unit  158 , the notification unit  159 , and the instruction unit  160  to execute processing described below. When the control unit  101  executes the program, the control unit  101  unfolds the program in the RAM  103 . Then, the control unit  101  causes the CPU  102  to interpret and execute the program unfolded in the RAM  103  to control each component. The electrocardiogram storage unit  171  and the blood pressure value storage unit  172  are provided in the storage unit  105 . 
     The input unit  151  receives an input from the user. The input unit  151  receives, from the input device  107 , an operation signal corresponding to an operation performed by the user on the input device  107  and determines contents of an instruction input by the user based on the operation signal. The instruction is, for example, an instruction to start electrocardiogram measurement, an instruction to start blood pressure measurement, an instruction to suspend electrocardiogram measurement, an instruction to suspend blood pressure measurement, an instruction to browse a history of measurement results, or the like. For example, in a case where the user instructs the start of electrocardiogram measurement, the input unit  151  gives the electrocardiogram measurement control unit  153  a measurement start instruction signal instructing the start of the measurement. In a case where the user instructs suspension of measurement during blood pressure measurement, the input unit  151  gives the blood pressure measurement control unit  155  a measurement end instruction signal instructing the suspension of the measurement. 
     The display control unit  152  controls the display device  106  and causes the display device  106  to display information. For example, the display control unit  152  receives a message from the notification unit  159  and causes the display device  106  to display the message. The display control unit  152  receives a message from the instruction unit  160  and causes the display device  106  to display the message. After blood pressure measurement, the display control unit  152  causes the display device  106  to display measurement results of blood pressure. 
     The electrocardiogram measurement control unit  153  controls an operation associated with electrocardiogram measurement. The electrocardiogram measurement control unit  153  drives the signal processing circuit  133  to perform electrocardiogram measurement. For example, when the electrocardiogram measurement control unit  153  receives a measurement start instruction signal from the input unit  151 , the electrocardiogram measurement control unit  153  drives the signal processing circuit  133 . The electrocardiogram acquisition unit  154  acquires, as an electrocardiogram, a potential difference signal output from the signal processing circuit  133  by a time series, and stores the electrocardiogram in the electrocardiogram storage unit  171  in association with time information. 
     The blood pressure measurement control unit  155  controls an operation associated with blood pressure measurement. The blood pressure measurement control unit  155  controls the pump drive circuit  146  and the valve drive circuit  147  to perform blood pressure measurement by the oscillometric method. The blood pressure measurement control unit  155  brings the valve  144  into a closed state via the valve drive circuit  147  and drives the pump  143  via the pump drive circuit  146 . Accordingly, supply of air to the pressing cuff  141  starts. The pressing cuff  141  is inflated, and compresses the left wrist of the user. When calculation of a blood pressure value by the blood pressure value calculation unit  156  is completed, the blood pressure measurement control unit  155  stops the pump  143  via the pump drive circuit  146  and brings the valve  144  into an open state via the valve drive circuit  147 . Accordingly, air is discharged from the pressing cuff  141 . The blood pressure measurement control unit  155  monitors cuff pressure by using the pressure sensor  142 . In a case where cuff pressure exceeds an upper pressure limit before the calculation of a blood pressure value by the blood pressure value calculation unit  156  is completed, the blood pressure measurement control unit  155  stops the pump  143  via the pump drive circuit  146  and brings the valve  144  into the open state via the valve drive circuit  147 . The upper pressure limit is predetermined from the viewpoint of safety. The upper pressure limit is determined to be 300 mmHg, for example. 
     In a pressurizing process of supplying air to the pressing cuff  141 , the blood pressure value calculation unit  156  calculates a blood pressure value by the oscillometric method based on a pressure signal output from the pressure sensor  142 . The blood pressure value includes systolic blood pressure (SBP) and diastolic blood pressure (DBP), but is not limited to these. The blood pressure value calculation unit  156  causes the blood pressure value storage unit  172  to store a calculated blood pressure value in association with time information. The blood pressure value calculation unit  156  can calculate a pulse rate together with a blood pressure value. 
     The measurement end detection unit  157  detects the end of electrocardiogram measurement. For example, the measurement end detection unit  157  measures time having elapsed since the start of electrocardiogram measurement. The start of electrocardiogram measurement is, for example, timing at which the right hand of the user comes into contact with the electrode  132 . The contact of the right hand of the user with the electrode  132  can be detected based on, for example, a potential difference signal output from the signal processing circuit  133 . The measurement end detection unit  157  determines the end of electrocardiogram measurement when a predetermined period of time (for example, 30 seconds) has elapsed since the start of electrocardiogram measurement. The measurement end detection unit  157  gives the electrocardiogram measurement control unit  153 , the blood pressure measurement control unit  155 , the posture detection unit  158 , the notification unit  159 , and the instruction unit  160  a notification signal notifying of the end of electrocardiogram measurement. When the electrocardiogram measurement control unit  153  receives the notification signal from the measurement end detection unit  157 , the electrocardiogram measurement control unit  153  stops the signal processing circuit  133 . Accordingly, an electrocardiogram for a predetermined period of time is recorded. 
     Note that the measurement end detection unit  157  may determine the end of electrocardiogram measurement when the user releases the right hand from the electrode  132  after a predetermined period of time has elapsed since the start of electrocardiogram measurement. In this case, the measurement end detection unit  157  may notify the user that a predetermined period of time has elapsed since the start of electrocardiogram measurement. Additionally, when the measurement end detection unit  157  detects the end of electrocardiogram measurement, the measurement end detection unit  157  may give the notification signal to the blood pressure measurement control unit  155 , the posture detection unit  158 , the notification unit  159 , and the instruction unit  160 , and when the user releases the right hand from the electrode  132 , the measurement end detection unit  157  may provide the notification signal to the electrocardiogram measurement control unit  153 . In these cases, an electrocardiogram for a period of time from the contact of the right hand of the user with the electrode  132  to the release of the right hand from the electrode  132  is recorded. 
     The posture detection unit  158  detects, based on the acceleration signal output from the acceleration sensor  108 , that the user is in posture appropriate for blood pressure measurement. The posture appropriate for blood pressure measurement is, for example, posture as illustrated in  FIG. 6  in which the left wrist that is a target measurement site is at the same height as the height of a heart. As described above, in the attachment state, the body  123  is positioned in the surface of the back side of the left wrist. Thus, whether the user is in posture appropriate for blood pressure measurement can be determined by detecting movement or inclination of the body  123  of the measurement device  100  based on the acceleration signal. Again with reference to  FIG. 5 , when the posture detection unit  158  detects that the user is in posture appropriate for blood pressure measurement, the posture detection unit  158  gives the blood pressure measurement control unit  155  and the instruction unit  160  a detection signal representing that the user is in posture appropriate for blood pressure measurement. When the blood pressure measurement control unit  155  receives the detection signal from the posture detection unit  158 , the blood pressure measurement control unit  155  starts blood pressure measurement. In other words, the blood pressure measurement control unit  155  starts blood pressure measurement in response to the measurement end detection unit  157  that has detected the end of electrocardiogram measurement and in response to the posture detection unit  158  that has detected that the user is in posture appropriate for blood pressure measurement. 
     Generally, it is known that a measurement value of blood pressure deviates from an original value in accordance with a difference in the height between the heart and the target measurement site (the left wrist in this example). For example, in a case where the height of the target measurement site relative to the heart as a reference is 10 cm, a blood pressure difference of approximately 8 mmHg occurs. No blood pressure difference occurs in the measurement performed in posture in which the left wrist is at the same height as the height of the heart, and thus a highly reliable measurement value can be obtained. 
     In response to the measurement end detection unit  157  that has detected the end of electrocardiogram measurement, the notification unit  159  notifies the user that blood pressure measurement is to be performed. The notification unit  159 , for example, emits alert sound via the speaker  109 , and also causes the display device  106  to display a message “Electrocardiogram measurement has ended. Next, blood pressure measurement will start.” The notification unit  159  gives a message to the display control unit  152 , and the display control unit  152  causes the display device  106  to display the message. The message may be voice-synthesized and may be output via the speaker  109 . 
     When the posture detection unit  158  does not detect that the user is in posture appropriate for blood pressure measurement, before a predetermined period of time (for example, 15 seconds) has elapsed since the end of electrocardiogram measurement, the instruction unit  160  instructs the user to assume posture appropriate for blood pressure measurement. The instruction unit  160  receives a notification signal from the measurement end detection unit  157 , and measures time having elapsed since the end of electrocardiogram measurement. In a case where the instruction unit  160  does not receive a detection signal from the posture detection unit  158  before the predetermined period of time has elapsed since the end of electrocardiogram measurement, the instruction unit  160  instructs the user. The instruction unit  160 , for example, emits alert sound via the speaker  109 , and also causes the display device  106  to display a message “Assume posture for blood pressure measurement”. The instruction unit  160  gives a message to the display control unit  152 , and the display control unit  152  causes the display device  106  to display the message. The message may be voice-synthesized and may be output via the speaker  109 . 
     Note that, in the present embodiment, the example where any of functions of the measurement device  100  is realized by a general-purpose processor is described. However, a portion or all of the functions may be realized by one or more dedicated processors. 
     Operation Example 
     Measurement of Electrocardiogram and Blood Pressure 
       FIG. 7  illustrates an operation flow performed when the measurement device  100  performs blood pressure measurement after electrocardiogram measurement. 
     At step S 11  of  FIG. 7 , the control unit  101  of the measurement device  100  measures an electrocardiogram of the user. For example, when the user instructs the start of electrocardiogram measurement through the input device  107 , the control unit  101  operates as the electrocardiogram measurement control unit  153  to drive the signal processing circuit  133 . At this time, the control unit  101  may operate as the display control unit  152  to cause the display device  106  to display a message that prompts the user to touch the electrode with the right hand. Then, the control unit  101  operates as the electrocardiogram acquisition unit  154 , and acquires, as an electrocardiogram, a potential difference signal based on a potential difference between the electrode  131  and the electrode  132  and output from the signal processing circuit  133  by a time series. 
     At step S 12 , the control unit  101  operates as the measurement end detection unit  157  to detect the end of the measurement of the electrocardiogram. For example, when a predetermined period of time (for example, 30 seconds) has elapsed since the start of electrocardiogram measurement, the control unit  101  determines the end of electrocardiogram measurement, and then stops the signal processing circuit  133 . 
     At step S 13 , the control unit  101  operates as the notification unit  159  to notify the user that blood pressure measurement is to be performed. For example, the control unit  101  emits alert sound via the speaker  109  and/or causes the display device  106  to display a message representing that blood pressure measurement is to be performed. 
     At step S 14 , the control unit  101  operates as the posture detection unit  158  and determines whether the user is in posture appropriate for blood pressure measurement. In a case where the user does not assume posture appropriate for blood pressure measurement before a predetermined period of time (for example, 15 seconds) has elapsed since the end of electrocardiogram measurement, the processing proceeds to step S 15 . At step S 15 , the control unit  101  operates as the instruction unit  160  to instruct the user to assume posture appropriate for blood pressure measurement. For example, the control unit  101  emits alert sound through the speaker  109 , and also causes the display device  106  to display a message that prompts the user to assume posture appropriate for blood pressure measurement. 
     At step S 16 , the control unit  101  operates as the posture detection unit  158  to determine whether the user is in posture appropriate for blood pressure measurement. In a case where the user does not assume posture appropriate for blood pressure measurement before a predetermined period of time (for example, 10 seconds) has elapsed since the notification, the processing ends without performing blood pressure measurement. 
     In a case where, at step S 14  or S 16 , the control unit  101  detects that the user is in posture appropriate for blood pressure measurement, the processing proceeds to step S 17 . At step S 17 , the control unit  101  operates as the blood pressure measurement control unit  155  and the blood pressure value calculation unit  156  to measure blood pressure of the user. The blood pressure measurement will be described below with reference to  FIG. 8 . 
     In this way, the measurement device  100  executes blood pressure measurement after electrocardiogram measurement. 
     Blood Pressure Measurement by Oscillometric Method 
       FIG. 8  illustrates an operation flow performed when the measurement device  100  performs blood pressure measurement by the oscillometric method. The control unit  101  starts blood pressure measurement by the oscillometric method in response to, for example, the user taking posture appropriate for blood pressure measurement or in response to the user instructing the start of blood pressure measurement via the input device  107 . 
     At step S 21  of  FIG. 8 , the control unit  101  operates as the blood pressure measurement control unit  155  to perform initialization for blood pressure measurement. For example, the control unit  101  initializes a memory region for processing. Further, the control unit  101  opens the valve  144  via the valve drive circuit  147 . Accordingly, air inside the pressing cuff  141  is discharged. Subsequently, the control unit  101  sets a current output value of the pressure sensor  142  as a reference value for cuff pressure. 
     At step S 22 , the control unit  101  operates as the blood pressure measurement control unit  151  to perform control of pressurizing the pressing cuff  141 . For example, the control unit  101  closes the valve  144  via the valve drive circuit  147  and drives the pump  143  via the pump drive circuit  146 . Accordingly, air is supplied to the pressing cuff  141  to inflate the pressing cuff  141 , and also cuff pressure Pc gradually increases as illustrated in  FIG. 9 . The control unit  101  monitors the cuff pressure Pc by the pressure sensor  142  and acquires a pulse wave signal Pm representing a variable component of arterial volume. 
     At step S 23  of  FIG. 8 , the control unit  101  operates as the blood pressure value calculation unit  156  and attempts to calculate a blood pressure value (systolic blood pressure and diastolic blood pressure) based on the pulse wave signal Pm acquired at this point of time. In a case where a blood pressure value cannot be calculated yet due to lack of data at this point of time (No at step S 24 ), the processing at steps S 22  and S 24  is repeated as long as the cuff pressure Pc does not reach an upper pressure limit. 
     When a blood pressure value can be calculated (Yes at step S 24 ), at step S 25 , the control unit  101  operates as the blood pressure measurement control unit  155 , stops the pump  143  via the pump drive circuit  146 , and opens the valve  144  via the valve drive circuit  147 . Accordingly, air inside the pressing cuff  141  is discharged. At step S 26 , the control unit  101  causes the display device  106  to display blood pressure measurement results and also records the blood pressure measurement results in the storage unit  105 . 
     Note that the processing procedure illustrated in  FIG. 7  or  FIG. 8  is merely an example and the processing procedure can be changed appropriately. For example, in a case where, at step S 15  of  FIG. 7 , the user does not assume posture appropriate for blood pressure measurement before a predetermined period of time has elapsed since the instruction, the control unit  101  may instruct again. Even in a case where, at step S 14  or S 16 , the user does not assume posture appropriate for blood pressure measurement, the control unit  101  may measure blood pressure of the user. In this case, for example, the control unit  101  may add, to the blood pressure measurement results, information representing that the user has not been in posture appropriate for blood pressure measurement. Additionally, the calculation of a blood pressure value is executed in the pressurizing process in which air is supplied to the pressing cuff  141 , but may be executed in the depressurizing process in which air inside the pressing cuff  141  is discharged. 
     Effects 
     The measurement device  100  according to the first embodiment determines whether electrocardiogram measurement has ended, and in a case where it is determined that electrocardiogram measurement has ended, the measurement device  100  determines whether the user is in posture appropriate for blood pressure measurement, and in a case where it is determined that the user is in posture appropriate for blood pressure measurement, the measurement device  100  performs blood pressure measurement. Thus, blood pressure measurement is performed after the end of electrocardiogram measurement without the user instructing the start of blood pressure measurement. Accordingly, the user can be prevented from forgetting to measure blood pressure after electrocardiogram measurement. Further, since an electrocardiograph and a blood pressure monitor are integrated, both an electrocardiogram and blood pressure can be measured simply by attaching one device, and this is highly convenient for the user. Since blood pressure measurement is performed in a state where the user is in posture appropriate for blood pressure measurement, reliability of a blood pressure measurement value is very high. 
     In response to the end of electrocardiogram measurement, the measurement device  100  notifies the user that blood pressure measurement is to be performed. Accordingly, the user can recognize the start of blood pressure measurement to assume posture appropriate for blood pressure measurement. When the user does not assume posture appropriate for blood pressure measurement after the notification, the measurement device  100  instructs the user to assume posture appropriate for blood pressure measurement. Accordingly, the user can perform blood pressure measurement in posture appropriate for blood pressure measurement. As a result, a highly reliable blood pressure measurement value can be obtained. 
     Second Embodiment 
     Configuration Example 
     Hardware Configuration 
     A measurement device according to the second embodiment can include a hardware configuration similar to the hardware configuration of the measurement device  100  according to the first embodiment (illustrated in  FIGS. 2 to 4 ). Specifically, the measurement device according to the second embodiment includes a control unit  101  including a CPU  102 , a RAM  103 , a ROM  104 , and the like, a storage unit  105 , a display device  106 , an input device  107 , an acceleration sensor  108 , a speaker  109 , a communication interface  110 , a battery  111 , a belt portion  120 , an electrode  131 , an electrode  132 , a signal processing circuit  133 , a pressure sensor  142 , a pump  143 , a valve  144 , an oscillation circuit  145 , a pump drive circuit  146 , and a valve drive circuit  147 . These components are described above with reference to  FIGS. 2 to 4 , and thus description of the components will be omitted. 
     Software Configuration 
     An example of a software configuration of a measurement device  200  according to the second embodiment will be described with reference to  FIG. 10 . In the example of  FIG. 10 , the measurement device  200  includes an input unit  251 , a display control unit  252 , an electrocardiogram measurement control unit  253 , an electrocardiogram acquisition unit  254 , a blood pressure measurement control unit  255 , a blood pressure value calculation unit  256 , a measurement end detection unit  257 , a posture detection unit  258 , a notification unit  259 , an instruction unit  260 , a contact detection unit  261 , an electrocardiogram storage unit  271 , and a blood pressure value storage unit  272 . The control unit  101  of the measurement device  200  executes a program stored in the storage unit  105  to cause the input unit  251 , the display control unit  252 , the electrocardiogram measurement control unit  253 , the electrocardiogram acquisition unit  254 , the blood pressure measurement control unit  255 , the blood pressure value calculation unit  256 , the measurement end detection unit  257 , the posture detection unit  258 , the notification unit  259 , the instruction unit  260 , and the contact detection unit  261  to execute processing described below. When the control unit  101  executes the program, the control unit  101  unfolds the program in the RAM  103 . Then, the control unit  101  causes the CPU  102  to interpret and execute the program unfolded in the RAM  103  to control each component. The electrocardiogram storage unit  271  and the blood pressure value storage unit  272  are realized by the storage unit  105 . 
     The input unit  251  receives an input from a user. For example, in a case where the user instructs the start of blood pressure measurement by operating the input device  107 , the input unit  251  gives a measurement start instruction signal to the blood pressure measurement control unit  255  and the posture detection unit  258 . In a case where the user instructs suspension of measurement during electrocardiogram measurement, the input unit  251  gives a measurement end instruction signal to the electrocardiogram measurement control unit  253 . 
     The display control unit  252  controls the display device  106 . For example, the display control unit  252  receives a message from the notification unit  259  and causes the display device  106  to display the message. The display control unit  252  receives a message from the instruction unit  260  and causes the display device  106  to display the message. After blood pressure measurement, the display control unit  252  causes the display device  106  to display blood pressure measurement results. 
     The electrocardiogram measurement control unit  253  controls an operation associated with electrocardiogram measurement. The electrocardiogram measurement control unit  253  drives the signal processing circuit  133  to perform electrocardiogram measurement. The electrocardiogram acquisition unit  254  acquires, as an electrocardiogram, a potential difference signal output from the signal processing circuit  133  by a time series, and stores the electrocardiogram in the electrocardiogram storage unit  271  in association with time information. 
     As with the posture detection unit  158  ( FIG. 5 ) of the first embodiment, the posture detection unit  258  detects that the user is in posture appropriate for blood pressure measurement. When the posture detection unit  258  detects that the user is in posture appropriate for blood pressure measurement, the posture detection unit  258  gives the blood pressure measurement control unit  255  a detection signal representing that the user is in posture appropriate for blood pressure measurement. 
     The blood pressure measurement control unit  255  controls an operation associated with blood pressure measurement. The blood pressure measurement control unit  255  controls the pump drive circuit  146  and the valve drive circuit  147  to perform blood pressure measurement by the oscillometric method. For example, when the blood pressure measurement control unit  255  receives a measurement start instruction signal from the input unit  251 , the blood pressure measurement control unit  255  starts blood pressure measurement. Specifically, the blood pressure measurement control unit  255  performs initialization for blood pressure measurement. Then, when the blood pressure measurement control unit  255  receives the detection signal from the posture detection unit  258 , the blood pressure measurement control unit  255  brings the valve  144  into a closed state via the valve drive circuit  147  and drives the pump  143  via the pump drive circuit  146 . As with the blood pressure measurement control unit  155  ( FIG. 5 ) of the first embodiment, the blood pressure measurement control unit  255  performs blood pressure measurement. Thus, specific description of blood pressure measurement will be omitted. The blood pressure value calculation unit  256  calculates a blood pressure value by a method similar to the method of the blood pressure value calculation unit  156  ( FIG. 5 ) of the first embodiment, and causes the blood pressure value storage unit  272  to store a calculated blood pressure value in association with time information. 
     The measurement end detection unit  257  detects the end of blood pressure measurement. For example, when cuff pressure becomes below a pressure threshold (for example, 10 mmHg) after the blood pressure value calculation unit  256  calculates a blood pressure value, the measurement end detection unit  257  determines the end of blood pressure measurement. When the blood pressure value calculation unit  256  can calculate a blood pressure value, the measurement end detection unit  257  may determine the end of blood pressure measurement. The measurement end detection unit  257  gives the electrocardiogram measurement control unit  253 , the notification unit  259 , the instruction unit  260 , and the contact detection unit  261  a notification signal notifying the end of blood pressure measurement. When the electrocardiogram measurement control unit  253  receives the notification signal from the measurement end detection unit  257 , the electrocardiogram measurement control unit  253  drives the signal processing circuit  133 . 
     When the notification unit  259  receives the notification signal from the measurement end detection unit  257 , that is, in response to the measurement end detection unit  257  that has detected the end of blood pressure measurement, the notification unit  259  notifies the user that electrocardiogram measurement is to be performed. The notification unit  259 , for example, emits alert sound via the speaker  109 , and also causes the display device  106  to display a message “Blood pressure measurement has ended. Next, electrocardiogram measurement will start.” The notification unit  259  gives a message to the display control unit  252 , and the display control unit  252  causes the display device  106  to display the message. The message may be voice-synthesized and may be output via the speaker  109 . 
     The contact detection unit  261  detects contact of the user (specifically, a right hand of the user) with the electrode  132 . The contact of the user with the electrode  132  can be detected based on, for example, a potential difference signal output from the signal processing circuit  133 . The contact detection unit  261  gives the electrocardiogram measurement control unit  253  and the instruction unit  260  a detection signal representing the contact of the user with the electrode  132 . 
     When the contact detection unit  261  does not detect the contact of the user with the electrode  132  before a predetermined period of time ( 15  seconds, for example) has elapsed since the detection of the end of blood pressure measurement by the measurement end detection unit  257 , the instruction unit  260  instructs the user to touch the electrode  132  with the right hand. The instruction unit  260  receives a notification signal from the measurement end detection unit  257 , and measures time having elapsed since the end of electrocardiogram measurement. In a case where the instruction unit  260  does not receive the detection signal from the contact detection unit  261  before a predetermined period of time has elapsed since the end of blood pressure measurement, the instruction unit  260  instructs the user. The instruction unit  260 , for example, emits alert sound via the speaker  109 , and also causes the display device  106  to display a message “Touch electrode with right hand finger.” Specifically, the instruction unit  260  gives a message to the display control unit  252 , and the display control unit  252  causes the display device  106  to display the message. The message may be voice-synthesized and may be output via the speaker  109 . 
     Note that, in the present embodiment, the example where any of functions of the measurement device  200  is realized by a general-purpose processor. However, a portion or all of the functions may be realized by one or more dedicated processors. 
     Operation Example 
       FIG. 11  illustrates an operation flow performed when the measurement device  200  performs electrocardiogram measurement after blood pressure measurement. 
     At step S 31  of  FIG. 11 , the control unit  101  of the measurement device  200  measures blood pressure of the user. For example, when the user instructs the start of measurement through the input device  107 , the control unit  101  operates as the posture detection unit  158  to determine whether the user is in posture appropriate for blood pressure measurement. When the user takes posture appropriate for blood pressure measurement, the control unit  101  operates as the blood pressure measurement control unit  255  to control the pump drive circuit  146  and the valve drive circuit  147  to perform blood pressure measurement by the oscillometric method. 
     At step S 32 , the control unit  101  operates as the measurement end detection unit  257  to detect the end of blood pressure measurement. For example, after the control unit  101  calculates a blood pressure value, the control unit  101  stops the pump  143  via the pump drive circuit  146  and opens the valve  144  via the valve drive circuit  147 . Accordingly, air is discharged from a pressing cuff  141 . When cuff pressure becomes below a pressure threshold (for example,  10  mmHg), the control unit  101  determines the end of blood pressure measurement. 
     At step S 33 , the control unit  101  operates as the notification unit  259  to notify the user that electrocardiogram measurement is to be performed. For example, the control unit  101  emits alert sound via the speaker  109  and/or causes the display device  106  to display a message representing that electrocardiogram measurement is to be performed. At step S 34 , the control unit  101  operates as the electrocardiogram measurement control unit  253  to drive the signal processing circuit  133 . 
     At step S 35 , the control unit  101  operates as the contact detection unit  261  to determine whether the right hand of the user has come into contact with the electrode  132 . In a case where the right hand of the user does not come into contact with the electrode  132  before a predetermined period of time (for example, 15 seconds) has elapsed since the end of blood pressure measurement, the processing proceeds to step S 36 . At step S 36 , the control unit  101  operates as the instruction unit  260  to instruct the user to touch the electrode  132  with the right hand. For example, the control unit  101  emits alert sound through the speaker and also causes the display device  106  to display a message prompting the user to touch the electrode  132  with the right hand. 
     At step S 37 , the control unit  101  operates as the contact detection unit  261  to determine whether the right hand of the user has come into contact with the electrode  132 . In a case where the right hand of the user does not come into contact with the electrode  132  before a predetermined period of time (for example,  10  seconds) has elapsed since the notification, the processing proceeds to step S 39 . At step S 39 , the control unit  101  operates as the electrocardiogram measurement control unit  253  to stop the signal processing circuit  133 . In this case, the processing ends without performing electrocardiogram measurement. 
     In a case where, at step S 35  or S 37 , the control unit  101  detects the contact of the right hand of the user with the electrode  132 , the processing proceeds to step S 38 . At step S 38 , the control unit  101  operates as the electrocardiogram acquisition unit  254  to acquire an electrocardiogram of the user. After measurement of an electrocardiogram is performed for a predetermined period of time (for example, 30 seconds), at step S 39 , the control unit  101  operates as the electrocardiogram measurement control unit  253  to stop the signal processing circuit  133 . 
     In this way, the measurement device  200  executes blood pressure measurement after electrocardiogram measurement. 
     Note that the processing procedure illustrated in  FIG. 11  is merely an example and the processing procedure can be changed appropriately. For example, in a case where the right hand of the user does not come into contact with the electrode  132  before a predetermined period of time has elapsed since the notification at step S 36  of  FIG. 11 , the control unit  101  may notify again. The processing at step S 34  may be executed before the processing at step S 33 . 
     Effects 
     The measurement device  200  according to the second embodiment determines whether blood pressure measurement has ended, and in a case where it is determined that blood pressure measurement has ended, the measurement device  200  performs electrocardiogram measurement. Thus, electrocardiogram measurement is performed after the end of blood pressure measurement without the user instructing the start of electrocardiogram measurement. Accordingly, the user can be prevented from forgetting to perform electrocardiogram measurement after blood pressure measurement. Further, since an electrocardiograph and a blood pressure monitor are integrated, both an electrocardiogram and blood pressure can be measured simply by attaching one device, and this is highly convenient for the user. 
     In response to the end of blood pressure measurement, the measurement device  200  notifies the user that electrocardiogram measurement is to be performed. Accordingly, the user can recognize the start of electrocardiogram measurement to touch the electrode  132  with the right hand. When the user does not touch the electrode  132  after the notification, the measurement device  200  instructs the user to touch the electrode  132  with the right hand. Accordingly, electrocardiogram measurement can be performed more securely. 
     Modified Examples 
     Note that the invention is not limited to the embodiments described above. 
     For example, in the measurement device  100  according to the first embodiment, the posture detection unit  158  may be removed. In a case where the posture detection unit  158  is removed, the blood pressure measurement control unit  155  starts blood pressure measurement in response to the measurement end detection unit  157  that has detected the end of electrocardiogram measurement. The measurement device  100  may further include a height detection unit that detects the height of a target measurement site relative to a heart as a reference, and a blood pressure measurement value may be corrected based on the height detected by the height detection unit. Additionally, after the user has taken posture appropriate for blood pressure measurement, the user may also press a button for starting blood pressure measurement. Similarly, in the measurement device  200  according to the second embodiment, the posture detection unit  258  may be removed. 
     The target measurement site is not limited to a wrist. The target measurement site may be any site in an upper limb such as an upper arm. The upper arm is positioned at approximately the same height as the height of the heart. Thus, in a case where the target measurement site is the upper arm, the user need not take such posture as illustrated in  FIG. 6  during blood pressure measurement. Thus, in the measurement device  100  according to the first embodiment, the posture detection unit  158 , the notification unit  159 , and the instruction unit  160  may be removed. Further, there is also no need to correct a blood pressure measurement value. 
     In short, the present invention is not limited to the embodiments described above as they are, and the component can be modified and embodied without departing from the gist of the present invention in a practical phase. Additionally, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiments described above. For example, some components may be omitted from all the components described in the embodiments. Further, the components of the different embodiments may be combined appropriately. 
     Supplementary Notes 
     A portion or all of the embodiments can be described as described in the following supplementary notes in addition to the scope of the claims, but is not limited to the supplementary notes. 
     Supplementary Note 1 
     A measurement device ( 10 ) including
         an electrocardiogram measurement unit ( 30 ) configured to measure an electrocardiogram reading of a user,   a blood pressure measurement unit ( 40 ) configured to measure blood pressure of the user,   a measurement end detection unit ( 50 ) configured to detect an end of electrocardiogram measurement by the electrocardiogram measurement unit, and a blood pressure measurement control unit ( 60 ) configured to start blood pressure measurement by the blood pressure measurement unit in response to the measurement end detection unit that has detected the end of the electrocardiogram measurement.       

     Supplementary Note 2 
     A measurement device ( 200 ) including
         an electrocardiogram measurement unit ( 30 ) configured to measure an electrocardiogram reading of a user,   a blood pressure measurement unit ( 40 ) configured to measure blood pressure of the user,   a measurement end detection unit ( 257 ) configured to detect an end of blood pressure measurement by the blood pressure measurement unit, and   an electrocardiogram measurement control unit ( 253 ) configured to start electrocardiogram measurement by the electrocardiogram measurement unit in response to the measurement end detection unit that has detected the end of the blood pressure measurement.       

     REFERENCE LIST 
       10  Measurement device 
       20  Belt portion 
       21  Outer circumferential surface 
       30  Electrocardiogram measurement unit 
       31  Electrode 
       32  Electrode 
       33  Electrocardiogram generation unit 
       40  Blood pressure measurement unit 
       50  Measurement end detection unit 
       60  Blood pressure measurement control unit 
       100  Measurement device 
       101  Control unit 
       102  CPU 
       103  RAM 
       104  ROM 
       105  Storage unit 
       106  Display device 
       107  Input device 
       108  Acceleration sensor 
       109  Speaker 
       110  Communication interface 
       111  Battery 
       120  Belt portion 
       121  Belt 
       122  Band-like body 
       123  Body 
       124  Three fold buckle 
       125  First plate-like member 
       126  Second plate-like member 
       127 ,  128  Connecting rod 
       129  Fixing portion 
       131  Electrode 
       132  Electrode 
       133  Signal processing circuit 
       134  Instrumentation amplifier 
       135  Low pass filter 
       136  Amplifier 
       137  Analog-to-digital converter 
       141  Pressing cuff 
       142  Pressure sensor 
       143  Pump 
       144  Valve 
       145  Oscillation circuit 
       146  Pump drive circuit 
       147  Valve drive circuit 
       148 ,  149  Pipe 
       151  Input unit 
       152  Display control unit 
       153  Electrocardiogram measurement control unit 
       154  Electrocardiogram acquisition unit 
       155  Blood pressure measurement control unit 
       156  Blood pressure value calculation unit 
       157  Measurement end detection unit 
       158  Posture detection unit 
       159  Notification unit 
       160  Instruction unit 
       171  Electrocardiogram storage unit 
       172  Blood pressure value storage unit 
       200  Measurement device 
       251  Input unit 
       252  Display control unit 
       253  Electrocardiogram measurement control unit 
       254  Electrocardiogram acquisition unit 
       255  Blood pressure measurement control unit 
       256  Blood pressure value calculation unit 
       257  Measurement end detection unit 
       258  Posture detection unit 
       259  Notification unit 
       260  Instruction unit 
       261  Contact detection unit 
       271  Electrocardiogram storage unit 
       272  Blood pressure value storage unit