Patent Publication Number: US-2021161399-A1

Title: Measurement device, measurement method, and non-transitory recording medium recording measurement program

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/JP2019/029026, filed Jul. 24, 2019, which application claims priority from Japanese Patent Application No. 2018-155466, filed Aug. 22, 2018, which applications are incorporated herein by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     The invention relates to a measurement device and a measurement method that enable blood pressure measurement and electrocardiographic measurement, and a non-transitory recording medium in which a measurement program enabling blood pressure measurement and electrocardiographic measurement is recorded, for example. 
     BACKGROUND ART 
     Patent Document 1 discloses a blood pressure measurement device. The blood pressure measurement device detects a pulse wave signal of a patient using a pulse wave sensor and calculates blood pressure based on the detected pulse wave signal. 
     CITATION LIST 
     Patent Literature 
     Patent Document 1: JP 2015-77229 A 
     SUMMARY OF INVENTION 
     Technical Problem 
     On the other hand, there is a need for electrocardiographic measurement in addition to blood pressure measurement. In this type of measurement device, a pair of electrodes is provided as electrocardiographic measurement electrodes. In a case where either of the pair of electrodes is not in proper contact with a target measurement site of a user, useful electrocardiographic measurement results may not be obtained. 
     In light of the circumstances described above, an object of one aspect is to provide a measurement device, a measurement method, and a measurement program that can properly achieve blood pressure measurement and electrocardiographic measurement. 
     Solution to Problem 
     In order to solve the problems described above, the present invention adopts the following measures, for example. 
     That is, a measurement device according to an example of the present disclosure includes a pressure acquisition unit configured to acquire pressure information representing pressure in a pressing cuff, a cuff pressure control unit configured to control, based on the pressure information, the pressure in the pressing cuff during each of a pressurizing step of pressurizing the pressing cuff, a pressurized state maintaining step of maintaining the pressing cuff in a pressurized state after end of the pressurizing step, and a depressurizing step of depressurizing the pressing cuff after end of the pressurized state maintaining step, a blood pressure calculation unit configured to calculate a blood pressure of a user based on the pressure information, an electrocardiographic measurement unit configured to measure an electrocardiogram of the user during the pressurized state maintaining step, and a first electrode and a second electrode as a pair of electrocardiographic electrodes, and the cuff pressure control unit is configured to maintain the pressure in the pressing cuff during the pressurized state maintaining step at a pressure at the end of the pressurizing step, and the second electrode is disposed at a position where the second electrode contacts the skin at an attachment site of the user in a state where the pressing cuff is attached to the user. 
     According to the configuration described above, an electrocardiogram is measured during the pressurized state maintaining step provided between the pressurizing step and the depressurizing step for the pressing cuff. Here, during the pressurized state maintaining step, the pressing cuff is expanded to cause the electrocardiographic measurement electrode to reliably contact an attachment site of the user and sufficiently closely contact the attachment site. Accordingly, an electrocardiogram in a proper attachment state can be measured, and proper electrocardiographic measurement results can be obtained. 
     In the measurement device according to the above-described example, the cuff pressure control unit is configured to set a duration of the pressurized state maintaining step equal to or longer than a measurement time required to obtain an electrocardiographic waveform useful for diagnosis. 
     According to the above-described configuration, the electrocardiogram in the proper attachment state can be measured, and the electrocardiographic waveform useful for diagnosis can be reliably acquired. 
     In the measurement device according to the above-described example, the cuff pressure control unit is configured to maintain the pressure in the pressing cuff during the pressurized state maintaining step at a constant value. 
     In the measurement device according to the example above, the blood pressure calculation unit is configured to calculate the blood pressure of the user based on a fluctuation in pressure in the pressing cuff during the pressurizing step for the pressing cuff or the depressurizing step for the pressing cuff, the fluctuation being acquired from the pressure information. 
     In the measurement device according to the example described above, the electrocardiographic measurement unit includes an electrocardiographic detection information acquisition unit configured to acquire detection information representing a current value flowing through the heart of a user between a pair of electrocardiographic measurement electrodes, and a generation unit configured to generate an electrocardiographic waveform reflecting the detection information during the pressurized state maintaining step for the pressing cuff based on the detection information acquired by the electrocardiographic detection information acquisition unit. 
     In the measurement device according to the above-described example, the electrocardiographic detection information acquisition unit is configured to acquire the detection information during a period from the pressurizing step through the depressurizing step, and the generation unit is configured to generate an electrocardiographic waveform reflecting only the detection information that is acquired during the pressurized state maintaining step, from among the detection information being acquired. 
     According to the above-described configuration, electrocardiographic waveforms reflecting only the detection results obtained in the proper attachment state. 
     In the measurement device according to the above-described example, the electrocardiographic detection information acquisition unit is configured to acquire, as the detection information, only the current value during the pressurized state maintaining step. 
     According to the above-described configuration, electrocardiographic measurement is performed only in the proper attachment state to reduce a burden on a patient. 
     The measurement device according to the example described above further includes, as the electrocardiographic measurement electrodes, a first electrode disposed at a position where the first electrode does not contact the skin at an attachment site of the user in a state where the measurement device is attached to the user, a second electrode disposed at a position where the second electrode contacts the skin at the attachment site of the user in a state where the measurement device is attached to the user, and the electrocardiographic detection information acquisition unit is configured to detect, as the detection information, a current flowing through the heart of the user between the first electrode and the second electrode. 
     The measurement device according to the example described above further includes a body including a first surface provided with a display unit and a second surface corresponding to a rear surface with respect to the first surface, and the pressing cuff configured to externally compress the attachment site of the user by being pressurized in a state where the pressing cuff is attached to the user, and the first electrode is disposed on the first surface of the body and the second electrode is disposed on the second surface of the body. 
     In the measurement device according to the example described above, the second electrode is attached to the user, and in a state where the pressing cuff is pressurized, the second electrode is pressed by the pressing cuff to closely contact the attachment site of the user. 
     Advantageous Effects of Invention 
     According to the present invention, a measurement device and a measurement method that can properly measure blood pressure and an electrocardiogram, and a non-transitory recording medium in which a measurement program that can properly measure blood pressure and an electrocardiogram is recorded are provided. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a block diagram illustrating an example of the functional configuration of a measurement device according to an application example. 
         FIG. 2  is a schematic diagram illustrating a configuration of a blood pressure measurement system including the measurement device according to a first embodiment. 
         FIG. 3  is a block diagram illustrating an example of the hardware configuration of the measurement device according to the first embodiment. 
         FIG. 4  is a diagram illustrating an example of a configuration of the measurement device according to the first embodiment. 
         FIG. 5  is a block diagram illustrating an example of the functional configuration of a blood pressure measurement circuit as an example of the measurement device according to the first embodiment. 
         FIG. 6  is a flowchart illustrating an example of a processing procedure for electrocardiographic measurement using the blood pressure measurement system including the blood pressure measurement circuit as an example of the measurement device according to the first embodiment. 
         FIG. 7  is a schematic diagram illustrating an example of a state in which the measurement device according to the first embodiment is attached to an attachment site of a user and electrocardiographic measurement processing is not performed. 
         FIG. 8  is a schematic diagram illustrating an example of a state in which the measurement device according to the first embodiment is attached to the attachment site of the user and pressurization of the pressing cuff is stopped in the electrocardiographic measurement processing. 
         FIG. 9  is a diagram illustrating an example of acquired results for an electrocardiographic waveform from the blood pressure measurement circuit as an example of the measurement device according to the first embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Now, with reference to the drawings, embodiments are described. Note that, in the following description, constituent elements having the same function and configuration are denoted with a shared reference symbol. Further, when a plurality of constituent elements having a shared reference symbol are distinguished from one another, distinguishment is made by adding additional symbols following the shared reference symbol. Note that, when there is no particular need in distinguishing a plurality of constituent elements, the plurality of constituent elements are denoted only with a shared reference symbol without an additional symbol. 
     1. Application Example 
     First, with reference to  FIG. 1 , an example of a measurement device to which the present invention is applied will be described. 
     The blood pressure measurement device  1  is an example of a measurement device that can measure the blood pressure and electrocardiogram of a user. The blood pressure measurement device  1  is attached to an attachment site of the user. The attachment site is, for example, a wrist, an upper arm, or the like. The blood pressure measurement device  1  executes a side effect management process based on a side effect management program. The side effect management program is an example of an electrocardiographic measurement program. As illustrated in  FIG. 1 , the blood pressure measurement device  1  includes a pressure acquisition unit  2 , a pressing cuff control unit  3 , a blood pressure calculation unit  4 , an electrocardiographic measurement unit  5 , and an output unit  6 . 
     The pressure acquisition unit  2  acquires pressure information. The pressure information includes the pressure in the pressing cuff (cuff pressure). The pressure acquisition unit  2  acquires pressure information from a pressure sensor provided in the pressing cuff, for example. 
     The pressing cuff control unit  3  controls the state of the pressing cuff based on the pressure information. The pressing cuff control unit  3  controls the state of the pressing cuff, for example, by controlling driving of a pump supplying a fluid to the pressing cuff and an exhaust valve provided in the pressing cuff. The pressing cuff control unit  3  expands and pressurizes the pressing cuff, for example, by supplying a fluid from the pump to the pressing cuff. The pressing cuff control unit  3  contracts and depressurizes the pressing cuff, for example, by discharging the fluid from the pressing cuff. The pressing cuff control unit  3  is an example of a cuff pressure control unit. 
     The blood pressure calculation unit  4  calculates the blood pressure of the user based on the pressure information. For example, an oscillometric method is used for the calculation of the blood pressure performed by the blood pressure calculation unit  4 . The blood pressure calculation unit  4  calculates the blood pressure based on, for example, a fluctuation in pressure in the pressing cuff during the pressurizing step for the pressing cuff. The blood pressure calculation unit  4  may calculate the blood pressure based on a fluctuation in pressure in the pressing cuff during the depressurizing step for the pressing cuff. The blood pressure calculated by the blood pressure calculation unit  4  is a systolic blood pressure, a diastolic blood pressure, or other index. 
     The electrocardiographic measurement unit  5  measures an electrocardiogram of the user based on detection information. The detection information includes, for example, a current value flowing through the heart of the user between a pair of electrocardiographic measurement electrodes. The electrocardiographic measurement unit  5  generates an electrocardiographic waveform based on the detection information. 
     The electrocardiographic measurement unit  5  sets the pressurized state maintaining step between the pressurizing step for the pressing cuff and the depressurizing step for the pressing cuff. The electrocardiographic measurement unit  5  generates an electrocardiographic waveform generated based on the detection information during the pressurized state maintaining step as electrocardiographic information. 
     The pressurized state maintaining step starts after the end of the pressurizing step, and ends before the start of the depressurizing step. In other words, the electrocardiographic measurement unit  5  measures an electrocardiogram of the user from the time when the pressurization of the pressing cuff is stopped until the depressurization of the pressing cuff is started. The electrocardiographic measurement unit  5  maintains the pressure in the pressing cuff at a constant value during the pressurized state maintaining step. In other words, the electrocardiographic measurement unit  5  maintains the pressing cuff in a pressurized state during the pressurized state maintaining step. For example, during the pressurized state maintaining step, the electrocardiographic measurement unit  5  performs control to maintain the pressure in the pressing cuff to the pressure at the end of the pressurizing step. 
     The duration of the pressurized state maintaining step is set, for example, equal to or longer than to a measurement time required to obtain an electrocardiographic waveform useful for diagnosis. 
     In an example, the electrocardiographic measurement unit  5 , for example, acquires detection information during a period from the pressurizing step through the pressurized state maintaining step and the depressurizing step, and generates an electrocardiographic waveform reflecting only the detection information that is acquired during the pressurized state maintaining step, from among the acquired detection information. In another example, the electrocardiographic measurement unit  5 , for example, acquires only the detection information during the pressurized state maintaining step, and generates an electrocardiographic waveform reflecting the acquired detection information. 
     The output unit  6  outputs the blood pressure information calculated by the blood pressure calculation unit  4  and the electrocardiographic information generated by the electrocardiographic measurement unit  5 . In this way, blood pressure measurement results and electrocardiographic measurement results are displayed on the display device. 
     In blood pressure measurement and electrocardiographic measurement, the pressurizing step for the pressing cuff is started in a state where the blood pressure measurement device  1  is attached to the attachment site of the user. As the pressing cuff is pressurized, the pressing cuff is expanded to compress the attachment site of the user. Then, in a state where the attachment site of the user is sufficiently compressed by the pressing cuff, the pressurization of the pressing cuff is stopped, and the pressurizing step ends. In a state where the pressurization of the pressing cuff is stopped, the electrocardiographic measurement electrodes are pressurized from the outside toward the attachment site of the user by the pressing cuff being expanded, and thus the electrocardiographic measurement electrodes reliably contact the attachment site of the user and sufficiently closely contact the attachment site. In a state where the attachment site of the user is not sufficiently compressed by the pressing cuff, the electrocardiograph electrodes may not sufficiently closely contact the attachment site of the user. 
     With the configuration described above, electrocardiogram is measured during the pressurized state maintaining step in which the pressing cuff is maintained in the pressurized state. As described above, between the pressurizing step and the depressurizing step, the pressing cuff maintained being pressurized, and the pressing cuff is expanded to cause the electrocardiographic measurement electrodes to reliably contact the attachment site of the user and sufficiently closely contact the attachment site. Accordingly, the blood pressure measurement device  1  can measure an electrocardiogram in a proper attachment state. As a result, proper electrocardiographic measurement results can be obtained. 
     2. First Embodiment 
     A first embodiment of the measurement device according to the application example described above will be described below. In the following, a blood pressure measurement system including a blood pressure measurement device will be described below. 
     2.1 Overall Configuration Example 
       FIG. 2  is a diagram schematically illustrating an example of an application scenario of the blood pressure measurement system according to the present embodiment. The blood pressure measurement system according to the present embodiment is a system for displaying blood pressure measurement results, electrocardiographic measurement results, and other information on a display screen. 
     The blood pressure measurement system includes a blood pressure measurement device  10 . The blood pressure measurement device  10  is an example of the measurement device. In the example in  FIG. 2 , the blood pressure measurement system further includes a portable terminal  11 , a physician terminal  12 , and a server  13 . A plurality of the blood pressure measurement devices  10  and a plurality of the portable terminals  11  may be provided. In this case, the blood pressure measurement devices  10  and the portable terminals  11  are connected by near-field wireless communication or wired communication. The portable terminal  11  can be connected to a server  13  via a network NW. The portable terminal  11  may be further connected to the physician terminal  12  via the network NW. The physician terminal  12  and the server  13  can be connected via a network NW, such as the Internet. A plurality of the physician terminals  12  may be provided. For communication between the physician terminal  12  and the server  13 , near-field wireless communication or wired communication, which are not via the network NW, may be applied. Thus, the blood pressure measurement device  10  can be connected to the server  13  (and the physician terminal  12 ) via the portable terminal  11 . That is, the blood pressure measurement device  10  can communicate with the server  13  (and the physician terminal  12 ) via the portable terminal  11 . 
     The blood pressure measurement device  10  is a device that can be attached to any measurement location. The measurement location may be, for example, the wrist, the upper arm, or the like. The blood pressure measurement device  10  can measure a blood pressure value of the user at a measurement location. The blood pressure measurement device  10  can transmit the blood pressure information including the measurement results of the blood pressure value and the like to the portable terminal  11 . Additionally, the blood pressure measurement device  10  can measure the electrocardiographic waveform of the user. The blood pressure measurement device  10  can transmit, to the portable terminal  11 , the electrocardiographic information including the electrocardiographic waveform being measured. The blood pressure measurement device  10  includes a clock function and can transmit the blood pressure information and the electrocardiographic information to the portable terminal  11  in association with a measured date/time. 
     For example, the portable terminal  11  is a terminal that can be carried by the user. The portable terminal  11  receives the blood pressure information and the electrocardiographic information from the blood pressure measurement device  10 . The portable terminal  11  can save the received blood pressure information and electrocardiographic information along with the measured date/time, for example. Additionally, the portable terminal  11  can transfer the saved blood pressure information and electrocardiographic information to the server  13  in association with the measured date/time as appropriate. 
     The physician terminal  12  is a terminal operable by an administrator such as a physician. The administrator such as a physician, for example, provide medical consultation to the user to diagnose the medical condition of the user based on test data and the like. The physician terminal  12  can receive test data from a test device (not illustrated) or the like in a hospital, and present the test data to the administrator. The diagnosis information related to the user is input to the physician terminal  12  by an operation of the administrator. The physician terminal  12  can transmit the input diagnosis information to the server  13 . 
     The server  13  is a server computer that accumulates information transmitted from the portable terminal  11 , the physician terminal  12 , and the like. The accumulated information is stored as an electronic medical chart, for example. 
     2.2 Hardware Configuration Examples 
     Description will be given of an example of a hardware configuration and an example of structure of the blood pressure measurement device in the blood pressure measurement system according to the present embodiment. 
     2.2.1 Hardware Configuration Example of Blood Pressure Measurement Device 
     First, a hardware configuration example of the blood pressure measurement device  10  according to the present embodiment will be described.  FIG. 3  is a block diagram illustrating an example of the hardware configuration of the blood pressure measurement device  10  according to the present embodiment. As illustrated in  FIG. 3 , the blood pressure measurement device  10  according to the present embodiment includes a control unit  21 , a storage unit  22 , a communication unit  23 , an operation unit  24 , a display unit  25 , a pressing cuff  26 , a pump  27 , a pressure sensor  28 , a battery  29 , a first electrode  30 , a second electrode  31 , and a detection circuit  32 . The blood pressure measurement device  10  may further include an acceleration sensor and a temperature/humidity sensor. 
     The control unit  21  includes a central processing unit (CPU), a random-access memory (RAM), a read-only memory (ROM), and the like, and controls each constituent element in accordance with information processing. Additionally, the control unit  21  includes a clock (not illustrated), and has a function of acquiring a current date/time. The control unit  21  may have a function of displaying the acquired date/time on the display unit  25 . 
     The control unit  21  drives the pump  27  to expand and contract the pressing cuff  26 . In addition, the control unit  21  controls the opening and closing of the exhaust valve provided in the pressing cuff  26 . In addition, the control unit  21  supplies electrical energy from the battery  29  to each of the first electrode  30  and the second electrode  31 , and applies different voltages to the first electrode  30  and the second electrode  31 . In addition, the control unit  21  generates blood pressure information and electrocardiographic information based on the measurement results obtained by the pressure sensor  28  and the detection circuit  32 . The blood pressure information includes, for example, the blood pressure value and the like of the user. The electrocardiographic information includes an electrocardiographic waveform and the like. Each of the blood pressure information and the electrocardiographic information is associated with the measured date/time, which is based on the current date/time acquired by the clock. Additionally, each of the blood pressure information and the electrocardiographic information may further be associated with a device ID for uniquely identifying the blood pressure measurement device  10 . 
     In addition, the control unit  21  executes electrocardiographic measurement processing based on an electrocardiographic measurement program. The electrocardiographic measurement processing by the control unit  21  will be described below. The electrocardiographic measurement program is a program for causing the control unit  21  to execute the electrocardiographic measurement processing. The electrocardiograph measurement program is stored in the storage unit  22 , for example. The electrocardiographic measurement program is an example of the measurement program. 
     The storage unit  22  is, for example, an auxiliary storage device such as a solid state drive, for example. In a case where the blood pressure measurement device  10  is configured as a somewhat large device rather than a small device such as a watch type, the storage unit  22  may be a hard disk drive. The storage unit  22  stores programs executed by the control unit  21 , the blood pressure information, the electrocardiographic information, setting information, and the like. 
     The communication unit  23  is a communication interface configured to perform communication with the portable terminal  11 . The communication unit  23  transmits, to the portable terminal  11 , the blood pressure information, pulse information, the electrocardiographic information, and the like, for example. Near-field wireless communication such as Bluetooth (trade name), for example, can be applied to communication with the portable terminal  11  made by the communication unit  23 , but no such limitation is intended. For example, communication performed by the communication unit  23  may adopt communication via the network NW such as a local area network (LAN) or wired communication through use of a communication cable. 
     For example, the operation unit  24  includes a user interface such as a touch panel and an operation button. The operation unit  24  detects an operation performed by the user via the user interface, and outputs a signal indicating the content of the operation to the control unit  21 . 
     The display unit  25  includes, for example, a display screen (for example, a liquid crystal display (LCD), an electroluminescent (EL) display, or the like), an indicator, and the like. The display unit  25  displays information in accordance with a signal from the control unit  21 , and notifies the information to the user. The display unit  25  can display, for example, blood pressure values, electrocardiographic waves, and the like. The display unit  25  is an example of a display screen. 
     The pressing cuff  26  is, for example, a band-like air bag. The pressing cuff  26  is supplied with a fluid to externally compress the attachment site of the user. 
     The pump  27  is, for example, a piezoelectric pump. The pump  27  may supply the fluid to the pressing cuff  26 . The fluid supplied from the pump  27  to the pressing cuff  26  is, for example, air. An exhaust valve controllably opened and closed depending on the state of the pump  27  is attached to the pump  27 . The exhaust valve is closed in a case where the pump  27  is in an on state, sealing air within the pressing cuff  26 . On the other hand, the exhaust valve is opened in a case where the pump  27  is in an off state, discharging air in the pressing cuff  26  into the atmosphere. In addition, the exhaust valve includes the function of a check valve. Thus, backflow of air discharged from inside the pressing cuff  26  is prevented. 
     The pressure sensor  28  is, for example, a piezoresistive pressure sensor. The pressure sensor  28  detects the pressure in the pressing cuff  26  through a flexible tube. The pressure sensor  28  outputs detection results to the control unit  21 . 
     The control unit  21  calculates the blood pressure value of the user based on the pressure in the pressing cuff  26  detected by the pressure sensor  28 . The blood pressure value includes representative indices such as, for example, a systolic blood pressure and a diastolic blood pressure. At this time, the control unit  21  calculates the blood pressure of the user on the spot (non-continuously) for a predetermined period of time, for example, based on the detection results from the pressure sensor  28 . The control unit  21  generates time series data of the pressure value using the detection results from the pressure sensor  28 , and calculates the blood pressure of the user for a predetermined period of time based on time series data of the pressure value. Thus, the pressure sensor  28  is an example of a non-continuous measurement type blood pressure sensor. For example, the non-continuous measurement type blood pressure sensor may adopt a method of detecting a pulse wave by applying a pressure to a blood vessel using the pressing cuff  26  as a pressure sensor (oscillometric method). 
     The battery  29  is, for example, a rechargeable secondary battery. The battery  29  stores power to be supplied to each element mounted in the blood pressure measurement device  10 . The battery  29  supplies power to the control unit  21 , the storage unit  22 , the communication unit  23 , the operation unit  24 , the display  25 , the pressing cuff  26 , the pump  27 , the pressure sensor  28 , the battery  29 , the first electrode  30 , the second electrode  31 , and the detection circuit  32 . 
     The first electrode  30  and the second electrode  31  are electrodes used for measuring the electrocardiographic waveform. The first electrode  30  and the second electrode  31  function as electrodes having different potentials by being supplied with power from the battery  29 . In a state where each of the first electrode  30  and the second electrode  31  is in contact with the skin of the user, the power is supplied to each of the first electrode  30  and the second electrode  31 , and thus current flows through the heart of the user between the first electrode  30  and the second electrode  31 . Each of the first electrode  30  and the second electrode  31  is an example of the electrocardiographic measurement electrode. 
     The first electrode  30  is provided in a portion of the blood pressure measurement device  10  that is exposed to the outside in a state where the blood pressure measurement device  10  is attached to the user. Additionally, the first electrode  30  is positioned in a position where the first electrode  30  can be operated by a user in a state where the blood pressure measurement device  10  is attached to the attachment site. The first electrode  30  does not contact the skin at the attachment site of the user in a state where the blood pressure measurement device  10  is attached to the user. In electrocardiographic measurement, the user presses the first electrode  30  with a finger using an arm opposite to the arm to which the blood pressure measurement device  10  is attached. 
     The second electrode  31  is provided on the blood pressure measurement device  10  at a position facing the skin at the attachment site in a state where the blood pressure measurement device  10  is attached to the attachment site. The second electrode  31  is disposed at a position where the blood pressure measurement device  10  contacts the skin at the attachment site of the user in a state where the blood pressure measurement device  10  is attached to the user. 
     The detection circuit  32  detects a current flowing through the heart of the user between the first electrode  30  and the second electrode  31 . The detection circuit  32  outputs an electrical signal indicating a current value of the detected current to the control unit  21 . The set of the first electrode  30 , the second electrode  31 , and the detection circuit  32  is an example of an electrocardiographic sensor. The set of the first electrode  30  and the second electrode  31  is an example of the electrocardiograph measurement electrodes. 
     2.2.2 Structure Example of Blood Pressure Measurement Device 
     A structure example of the blood pressure measurement device  10  corresponding to the measurement device according to the present embodiment will be described.  FIG. 4  is a perspective view illustrating an example of the structure of the blood pressure measurement device  10 . In an example in  FIG. 4 , the blood pressure measurement device  10  is a wristwatch type wearable device attached to the wrist of the user. As illustrated in  FIG. 4 , the blood pressure measurement device  10  includes a body  41 , a belt  42 , a cuff unit  43 , a conductor  44 , and a conductor  45 . The wrist is an example of the attachment site. The conductor  44  and the conductor  45  function as electrocardiographic measurement electrodes. 
     The body  41  has, for example, a substantially short cylindrical shape. A pair of belts  42  are attached to the side surface of the body  41 . Each belt of the pair of belts  42  is attached at one end to the side surface of the body  41 . The pair of belts  42  are connected to the body  41  on opposite side surfaces of the body  41 . 
     The body  41  is configured such that a plurality of elements of the blood pressure measurement device  10  can be mounted in the body  41 . The body  41  includes, for example, the control unit  21 , the storage unit  22 , the communication unit  23 , the operation unit  24 , the display unit  25 , the battery  29 , the first electrode  30 , the second electrode  31 , and the detection circuit  32 . 
     The body  41  includes a front surface  41 A and a rear surface  41 B. The front surface  41 A and the rear surface  41 B face opposite each other. The blood pressure measurement device  10  is attached to the wrist of the user such that the front surface  41 A faces outward. In a state where the blood pressure measurement device  10  is attached to the wrist of the user, the rear surface  41 B faces inward and faces the skin at the wrist of the user. The front surface  41 A is an example of a first surface. The rear surface  41 B is an example of a second surface. 
     A display screen is provided on the front surface  41 A, for example. The front surface  41 A functions as the display unit  25 . The display screen is a liquid crystal display (LCD), for example. The display screen may be an organic electro luminescence (EL) display. Additionally, the display screen may include a light emitting diode (LED). It is sufficient that the display screen includes a function of displaying various types of information, and limitation to the above-described configuration is not intended. 
     A plurality of push buttons  46  are provided on the side surface of the body  41 . The push buttons  46  function as the operation unit  24 . The push buttons  46  are used to input various instructions for the blood pressure measurement device  10 . For example, one of the push buttons  46  is used to input an instruction to start blood pressure measurement. Additionally, for example, another one of the push buttons  46  is used to input an instruction to start blood pressure measurement and electrocardiographic measurement. 
     The blood pressure measurement device  10  may include, instead of the push buttons  46 , a pressure sensitive type (resistance type) or a proximity type (capacitance type) touch panel type switch, as the operation unit  24 . It is sufficient that the operation unit  24  includes a function of inputting various instructions for the blood pressure measurement device  10 , and limitation to the above-described configuration is not intended. 
     The belt  42  is configured such that the belt  42  can be externally wrapped around the wrist of the user. The belt  42  includes a first belt portion  47  and a second belt portion  48 . The first belt portion  47  and the second belt portion  48  are each formed in band-like shape. The first belt portion  47  and the second belt portion  48  are formed of, for example, a resin material and have flexibility. One end of the first belt portion  47  is pivotally connected to the side surface of the body  41 . A fastening member is attached to the other end of the first belt portion  47 . One end of the second belt portion  48  is pivotally connected to a portion of the side surface of the body  41  opposite to the portion to which the first belt portion  47  is connected. The first belt portion  47  and the second belt portion  48  are fastened together by engaging the second belt portion  48  with the fastening member of the first belt portion  47 . By fastening the first belt portion  47  and the second belt portion  48  together, the blood pressure measurement device  10  is attached to the wrist of the user. 
     The belt  42  includes an outward facing surface  42 A and an inward facing surface  42 B. The outward facing surface  42 A and the inward facing surface  42 B face opposite each other. In a state where the blood pressure measurement device  10  is attached to the wrist of the user, the outward facing surface  42 A of the belt  42  faces outward. Additionally, in a state where the blood pressure measurement device  10  is attached to the wrist of the user, the inward facing surface  42 B of the belt  42  faces inward. 
     The cuff unit  43  is a band-like air bag. The cuff unit  43  is pivotally attached at one end to the side surface of the body  41 . The cuff unit  43  is disposed facing the inward facing surface  42 B of the belt  42 . The other end of the cuff unit  43  is a free end. Thus, the cuff unit  43  is freely spaced apart from the inner circumferential surface of the belt  42 . In a state where the blood pressure measurement device  10  is attached to the wrist H of the user, the cuff unit  43  is extended between the inward facing surface  42 B of the belt  42  and the wrist of the user. 
     The cuff unit  43  functions as the pressing cuff  26 . The cuff unit  43  is connected to the pump  27  through a flexible tube, for example. The cuff unit  43  is supplied with a fluid from the body  41  through the flexible tube. The fluid is, for example, air. The cuff unit  43  is expanded when the cuff unit  43  is supplied with the fluid from the pump  27  of the body  41 . Additionally, the cuff unit  43  is contracted when the air is discharged from inside the cuff unit  43 . When the fluid is supplied to the cuff unit  43  in a state where the blood pressure measurement device  10  is attached, the expansion of the cuff unit  43  compresses the wrist of the user. 
     The cuff unit  43  includes the outward facing surface  43 A and the inward facing surface  43 B. The inward facing surface  43 B faces the side opposite to the side faced by the outward facing surface  43 A. The outward facing surface  43 A of the cuff unit  43  faces the inward facing surface  42 B of the belt  42 . The inward facing surface  43 B faces the skin of the wrist in a state where the blood pressure measurement device  10  is attached to the wrist. Specifically, a part of the inward facing surface  43 B forms a part of a portion of the pressure measurement device  10  that faces the skin at the attachment site in a state where the pressure measurement device  10  is attached to the attachment site. Thus, in an example in  FIG. 4 , in a state where the blood pressure measurement device  10  is attached, the rear surface  41 B of the body  41  and the inward facing surface  43 B of the cuff unit  43  face the skin of the wrist of the user. 
     The conductor  44  is attached to the front surface  41 A of the body  41 . The conductor  44  has electrical conductivity. The conductor  44  is electrically connected to the battery  29  inside the body  41 . When power from the battery  29  is supplied to the conductor  44 , the conductor  44  functions as the first electrode  30 . In a state where the blood pressure measurement device  10  is attached to the attachment site, the first electrode  30  may be disposed at a position where the first electrode  30  is exposed to the outside. Accordingly, the conductor  44  may be disposed, for example, on the side surface of the body  41 , the outward facing surface  42 A of the belt  42 , or the like. 
     The conductor  45  is attached to the rear surface  41 B of the body  41 . The conductor  45  has electrical conductivity. The conductor  45  is electrically connected to the battery  29  inside the body  41 . When power from the battery  29  is supplied to the conductor  45 , the conductor  45  functions as the second electrode  31 . In a state where the blood pressure measurement device  10  is attached to the attachment site, the second electrode  31  may be disposed at a position where the second electrode  31  faces the skin at the attachment site. Accordingly, the conductor  45  may be disposed on the inward facing surface  43 B of the cuff unit  43 , for example. 
     2.3 Functional Configuration Examples 
     Now, an example of a functional configuration of the blood pressure measurement system according to the present embodiment will be described. 
     2.3.1 Functional Configuration Example of Blood Pressure Measurement Device 
       FIG. 5  is a block diagram schematically illustrating an example of a functional configuration of the blood pressure measurement device  10  of the blood pressure measurement system according to the present embodiment. 
     The control unit  21  of the blood pressure measurement device  10  deploys the electrocardiographic measurement program stored in a non-volatile memory of the storage unit  22  into a volatile memory of the storage unit  22 . Then, by interpreting and executing the electrocardiography measurement program deployed into the volatile memory, the control unit  21  functions as a pressure acquisition unit  61 , a blood pressure calculation unit  62 , a pressing cuff control unit  63 , a power control unit  64 , a current acquisition unit  65 , an electrocardiographic waveform generation unit  66 , and the output section  67 . 
     The volatile memory of the storage unit  22  functions as a pressure information storage unit  71 , a detection information storage unit  72 , a blood pressure information storage unit  73 , an electrocardiographic information storage unit  74 , and a setting information storage unit  75 . 
     The pressure information storage unit  71  stores pressure information. The pressure information includes the pressure in the pressing cuff  26  detected by the pressure sensor  28 . 
     Detection information detected by the detection circuit  32  is stored in the detection information storage unit  72 . The detection information includes a current value flowing between the first electrode  30  and the second electrode  31 . 
     The blood pressure information storage unit  73  stores blood pressure information. The blood pressure information includes a blood pressure value. The blood pressure value is a systolic blood pressure, a diastolic blood pressure, or other index. The blood pressure information can also include a measured date/time and a measurement location for each blood pressure value. 
     The electrocardiographic information storage unit  74  stores electrocardiographic information. The electrocardiographic information includes electrocardiographic waveform display data and the like. 
     Pieces of setting information used in the electrocardiographic measurement processing are stored in the setting information storage unit  75 . The setting information includes a threshold value and the like used in the electrocardiographic measurement processing. 
     The pressure acquisition unit  61  acquires the pressure (cuff pressure) in the pressing cuff  26 . The pressure acquisition unit  61  acquires the pressure in the pressing cuff  26  from the pressure sensor  28 , for example. The pressure acquisition unit  61  stores the acquired pressure in the pressure information storage unit  71  of the storage unit  22  as pressure information. 
     The blood pressure calculation unit  62  calculates the blood pressure value based on the pressure information acquired by the pressure acquisition unit  61 . The blood pressure value is, for example, a systolic blood pressure, a diastolic blood pressure, or other index. The blood pressure calculation unit  62  uses the oscillometric method to calculate the blood pressure value based on a fluctuation in pressure during compression of the attachment site, i.e., from a fluctuation in pressure during the pressurizing step or the depressurizing step for the pressing cuff  26 . The blood pressure calculation unit  62  stores the calculated blood pressure value in the blood pressure information storage unit  73  of the storage unit  22  as blood pressure information. 
     The pressing cuff control unit  63  controls the state of the pressing cuff  26  based on the pressure information acquired by the pressure acquisition unit  61 . The pressing cuff control unit  63  controls the amount of fluid supplied to the pressing cuff  26 , for example, by controlling the driving of the pump  27 . The pressing cuff control unit  63  is an example of a cuff pressure control unit. 
     The power control unit  64  controls power supplied from the battery  29  to the first electrode  30  and the second electrode  31 . The power control unit  64  may control the power supplied to the first electrode  30  and the second electrode  31  based on the pressure information acquired by the pressure acquisition unit  61 . 
     The current acquisition unit  65  acquires detection information. The detection information includes, for example, the current value of the current detected by the detection circuit  32 . The current acquisition unit  65  stores the acquired detection information in the detection information storage unit  72  of the storage unit  22 . The current acquisition unit  65  is an example of an electrocardiographic detection information acquisition unit. The current acquisition unit  65  is an example of an electrocardiographic measurement unit. 
     The electrocardiographic waveform generation unit  66  generates the electrocardiographic waveform display data based on the pressure information acquired by the pressure acquisition unit  61  and the detection information acquired by the current acquisition unit  65 . The electrocardiographic waveform display data is image data to be displayed on the display unit  25 . The electrocardiographic waveform display data is stored in the electrocardiographic information storage unit  74  of the storage unit  22  as electrocardiographic information. The electrocardiographic waveform generation unit  66  is an example of a generation unit. Additionally, the electrocardiographic waveform generation unit  66  is an example of an electrocardiographic measurement unit. 
     The electrocardiographic waveform generation unit  66  sets an electrocardiographic measurement time. The electrocardiographic measurement time is the time between the end of the pressurizing step and the start of the depressurizing step for the pressing cuff  26  in the electrocardiographic measurement processing. Thus, the electrocardiographic waveform generation unit  66  sets the pressurized state maintaining step between the pressurizing step and the depressurizing step. The electrocardiographic measurement time is, for example, the measurement time required to obtain an electrocardiographic waveform useful for diagnosis. The electrocardiographic measurement time is, for example, 10 seconds. The electrocardiographic measurement time is an example of the duration of the pressurized state maintaining step. The electrocardiographic measurement time is stored in the setting information storage unit  75  of the storage unit  22 , for example. 
     The electrocardiographic waveform generation unit  66  acquires detection information during a period from the pressurizing step through the depressurizing step. The electrocardiographic waveform generation unit  66  determines, among the acquired detection results, the detection results that correspond to the pressurizing step and the depressurizing step to be noise. The electrocardiographic waveform generation unit  66  excludes the detection results determined to be noise, and generates the electrocardiographic waveform display data. Thus, for example, the detection results from the detection circuit  32  during the pressurizing step and the depressurizing step for the pressing cuff  26  are not reflected in the electrocardiographic waveform display data. Accordingly, the electrocardiographic waveform generation unit  66  generates the electrocardiographic waveform display data based only on the current value detected by the detection circuit  32  during the pressurized state maintaining step. 
     The output unit  67  outputs, to the display unit  25 , the blood pressure information calculated by the blood pressure calculation unit  62 , and causes the display unit  25  to display blood pressure measurement results. In addition, the output unit  67  outputs, to the display unit  25 , the electrocardiographic waveform display data generated by the electrocardiographic waveform generation unit  66 , and causes the display unit  25  to display electrocardiographic measurement results. 
     2.4 Operation Examples 
     Now, an operation example of the blood pressure measurement system according to the present embodiment will be described. 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. 
     2.4.1 Operation Example of Blood Pressure Measurement System 
       FIG. 6  is a flowchart illustrating an example of a procedure of processing by the control unit  21  of the blood pressure measurement device  10 , in electrocardiographic measurement using the blood pressure measurement system according to the present embodiment. The control unit  21  starts the electrocardiographic measurement processing based on, for example, the input of an instruction to start electrocardiographic measurement at the operation unit  24  of the blood pressure measurement device  10  in a state where the blood pressure measurement device  10  is attached to the attachment site of the user. In the electrocardiographic measurement processing, the blood pressure and electrocardiogram of the user are measured, and the blood pressure measurement results and the electrocardiographic measurement results are displayed on the display unit  25 . 
       FIGS. 7 and 8  are diagrams illustrating a state in which the blood pressure measurement device  10  illustrated in the example in  FIG. 4  is attached to the wrist H of the user.  FIG. 7  illustrates a state in which the pressing cuff  26  is not expanded in the electrocardiographic measurement processing.  FIG. 8  illustrates a state in which the pressing cuff  26  is expanded in the electrocardiographic measurement processing. The wrist H is an example of the attachment site. 
     In the electrocardiographic measurement processing, first, the control unit  21  starts supplying power to the first electrode  30  and the second electrode  31  (S 101 ). At this time, the control unit  21  may, for example, cause the display unit  25  to provide display prompting the user to perform an electrocardiographic measurement operation. The control unit  21  causes the display unit  25  to display, for example, “Start electrocardiographic measurement,” “Press measurement button,” or the like as display prompting the user to perform an electrocardiographic measurement operation. Instead of the display on the display unit  25 , a sound, a lighting display, or the like may be used to prompt the user to perform the electrocardiographic measurement operation. 
     In an electrocardiographic measurement operation, in a state where the blood pressure measurement device  10  is attached to the attachment site, the user causes the first electrode  30  to contact a finger of the arm to which the blood pressure measurement device  10  is not attached. By performing the electrocardiographic measurement operation in a state where the second electrode  31  is in proper contact with the skin at the attachment site of the user, a current flows between the first electrode  30  and the second electrode  31  through the heart of the user. The detection circuit  32  detects the current flowing between the first electrode  30  and the second electrode  31  and outputs to the control unit  21 . 
     Then, the control unit  21  determines whether the electrocardiographic measurement operation is performed by the user (S 102 ). By this way, the control unit  21  determines whether an operation for starting electrocardiographic measurement is performed. The control unit  21  waits until the electrocardiographic measurement operation is performed. For example, the control unit  21  determines that the electrocardiographic measurement operation is performed based on the current waveform detected by the detection circuit  32  exhibiting a predetermined behavior. 
     When the electrocardiographic measurement operation is performed (S 102 —Yes), the control unit  21  starts pressurizing the pressing cuff  26  (S 103 ). At this time, the control unit  21  starts pressurizing the pressing cuff  26  by starting supplying of air from the pump  27  to the pressing cuff  26 . This starts the pressurizing step of the pressing cuff  26 . 
     Then, the control unit  21  determines whether a pressure P detected by the pressure sensor  28  is equal to or higher than a first threshold value Pth 1  (S 104 ). In other words, the control unit  21  determines whether the pressure in the pressing cuff  26  is equal to or higher than a predetermined value. The first threshold value Pth 1  is a predetermined pressure value at the end of pressurization of the pressing cuff  26  in the blood pressure measurement. The first threshold value Pth 1  is stored in the setting information storage unit  75  of the storage unit  22 , for example. 
     In a case where the pressure P is lower than the first threshold value Pth 1  (S 104 —No), the control unit  21  repeats the determination in S 104 . In other words, the control unit  21  continues the pressurization of the pressing cuff  26  until the pressure in the pressing cuff  26  is equal to or higher than a predetermined value. In a case where the pressure P is equal to or higher than the first threshold value Pth 1  (S 104 —Yes), the control unit  21  determines that the wrist H of the user is sufficiently compressed by the pressing cuff  26 . Then, the control unit  21  stops pressurizing the pressing cuff  26  (S 105 ). At this time, the control unit  21  stops supplying air from the pump  27  to the pressing cuff  26 , thus stopping pressurization of the pressing cuff  26 . Accordingly, the pressurizing step for the pressing cuff  26  ends. 
     As illustrated in the example in  FIG. 7 , in a state where the cuff unit  43  is not expanded, the conductor  45  does not sufficiently closely contact the wrist H of the user. That is, in a state where the pressing cuff  26  is not sufficiently pressurized, the second electrode  31  does not sufficiently closely contact the attachment site of the user. With the cuff unit  43  pressurized, expansion of the cuff unit  43  causes the conductor  45  to be externally pressed inward against the skin at the wrist H of the user. This increases the contact strength with which the conductor  45  contacts the wrist H of the user. 
     As illustrated in the example in  FIG. 8 , in a case where the pressure P in the cuff unit  43  is equal to or higher than the first threshold value Pth 1 , the conductor  45  contacts the wrist H of the user with sufficient contact strength. In other words, in a state where the pressing cuff  26  is sufficiently pressurized, the second electrode  31  properly contacts the attachment site of the user. 
     Then, the control unit  21  sets, as a reference time TO, the time at which the pressure P is determined to be equal to or higher than the first threshold value Pth 1  (S 106 ). The reference time TO is the time when the pressurizing step for the pressing cuff  26  ends. The control unit  21  continuously acquires an elapsed time dT from the reference time TO. 
     Then, the control unit  21  determines whether the elapsed time dT is equal to or longer than a threshold value Tth (S 107 ). The threshold value Tth is an example of an electrocardiographic measurement time, and is an example of the duration of the pressurized state maintaining step. The threshold value Tth is stored in the setting information storage unit  75  of the storage unit  22 , for example. By determining whether the elapsed time dT is equal to or longer than the threshold value Tth, the control unit  21  determines whether or not the electrocardiographic measurement time has elapsed during the pressurized state maintaining step. During the pressurized state maintaining step, the state is maintained in which the second electrode  31  is in proper contact with the attachment site of the user. 
     In a case where the elapsed time dT is shorter than the threshold Tth (S 107 —No), the control unit  21  repeats the determination in S 107 . In other words, the control unit  21  waits until the electrocardiographic measurement time elapses during the pressurized state maintaining step. 
     In a case where the elapsed time dT is equal to or longer than the threshold value Tth (S 107 —Yes), the control unit  21  determines that the electrocardiographic measurement time has elapsed during the pressurized state maintaining step. Then, the control unit  21  starts the depressurization of the pressing cuff  26  (S 108 ). At this time, the control unit  21  starts the depressurization of the pressing cuff  26  by causing air to flow out of the pressing cuff  26 . This starts the depressurizing step for the pressing cuff  26 . As air flows out of the pressing cuff  26 , the pressing cuff  26  in the expanded state is contracted, and the compression, by the pressing cuff  26 , of the wrist H of the user is correspondingly relaxed. 
     Then, the control unit  21  determines whether the pressure P detected by the pressure sensor  28  is equal to or lower than a second threshold value Pth 2  (S 109 ). In other words, the control unit  21  determines whether the pressure in the pressing cuff  26  is equal to or lower than a predetermined value. The second threshold value Pth 2  is a predetermined pressure value at the end of depressurizing step for the pressing cuff  26  in the blood pressure measurement. The second threshold value Pth 2  is stored in the setting information storage unit  75  of the storage unit  22 , for example. 
     In a case where the pressure P is higher than the second threshold value Pth 2  (S 109 —No), the control unit  21  repeats the determination in S 109 . In other words, the control unit  21  continues the depressurization of the pressing cuff  26  until the pressure in the pressing cuff  26  is equal to or lower than the predetermined value. In a case where the pressure P is equal to or lower than the second threshold value Pth 2  (S 109 —Yes), the control unit  21  stops the depressurization of the pressing cuff  26  (S 110 ). At this time, the control unit  21  stops the depressurization of the pressing cuff  26  by stopping the flow of air out of the pressing cuff  26 . This ends the depressurizing step for the pressing cuff  26 . 
     Then, the control unit  21  calculates the blood pressure value based on the pressure P in the pressing cuff  26  detected by the pressure sensor  28  (S 111 ). The control unit  21  uses the oscillometric method to calculate the systolic blood pressure and the diastolic blood pressure based on, for example, a fluctuation in pressure P in the pressing cuff  26  obtained between S 103  and S 110 . The control unit  21  may calculate other index such as an average value or a representative value of the blood pressure based on the systolic blood pressure and the diastolic blood pressure. The control unit  21  stores the calculated blood pressure value in the blood pressure information storage unit  73  of the storage unit  22 . 
     Note that the blood pressure calculation processing in S 111  may be continuously performed during the period from the start of the pressurizing step for the pressing cuff  26  (S 103 ) until the end of the depressurizing process for the pressing cuff  26  (S 110 ). The blood pressure calculation processing in S 111  may be performed based only on the detection results for the pressure P in the pressing cuff  26  during the pressurizing step for the pressing cuff  26 , or may be performed based only on the detection results for the pressure P in the pressing cuff  26  during the depressurizing step for the pressing cuff  26 . 
     Then, the control unit  21  generates the electrocardiographic waveform display data (S 112 ). The control unit  21  generates the electrocardiographic waveform display data using only the detection results from the detection circuit  32  acquired during a period from the stoppage of pressurization of the pressing cuff  26  until the start of depressurization of the pressing cuff  26 . The control unit  21  determines that, among the detection results from the detection circuit  32  during the period from the start of pressurization (S 103 ) until the end of depressurization (S 111 ), the detection results corresponding to the pressurizing step and the depressurizing step for the pressing cuff  26  are noise, and generates the electrocardiographic waveform display data reflecting only the detection results during the pressurized state maintaining step. The control unit  21  stores the generated electrocardiographic waveform display data in the electrocardiographic information storage unit  74  of the storage unit  22  as electrocardiographic measurement results. 
     Then, the control unit  21  causes the display unit  25  to display the blood pressure measurement results and the electrocardiographic measurement results (S 113 ). The control unit  21  causes the display unit  25  to display, as the blood pressure measurement results, the systolic blood pressure and the diastolic blood pressure calculated during the calculation of the blood pressure (S 111 ). Additionally, the control unit  21  causes the display unit  25  to display, as the electrocardiographic measurement results, the electrocardiographic waveform display data generated in the generation of the electrocardiographic waveform display data (S 112 ). 
     2.5 Actions and Effects 
     Now, an example of actions and effects of the blood pressure measurement system according to the present embodiment will be described. 
       FIG. 9  is a diagram illustrating an example of detection results from the detection circuit  32  during the electrocardiographic measurement processing illustrated in the example in  FIG. 6 . In the example in  FIG. 9 , the detection results from the detection circuit  32  include an electrocardiographic waveform A. The horizontal axis of the electrocardiographic waveform A indicates time T. Additionally, the vertical axis of the electrocardiographic waveform A indicates current I. 
     The electrocardiographic waveform A includes a first region A 1 , a second region A 2 , and a third region A 3 . The first region A 1  is based on the detection results during the pressurizing step. The second region A 2  is based on the detection results during the pressurized state maintaining step. The third region A 3  is based on the detection results during the depressurizing step. 
     Here, as is known, in the electrocardiographic measurement, proper measurement results fail to be obtained when the electrodes are not in proper contact with the skin at the attachment site. For example, as illustrated in the example in  FIG. 7 , during the pressurizing and depressurizing steps for the pressing cuff  26 , the second electrode  31  may fail to contact the wrist H of the user with sufficient contact strength. Thus, as illustrated in the example in  FIG. 9 , an unstable fluctuation is observed in the electrocardiographic waveform (first region A 1 ) based on the detection results during the pressurizing step for the pressing cuff  26 , and the electrocardiographic waveform (third region A 3 ) based on the detection results of the depressurizing step for the pressing cuff  26 , and these electromagnetic waveforms are preferably considered to be noise. 
     On the other hand, in the electrocardiographic measurement, proper measurement results can be obtained in a state where the electrodes are in proper contact with the skin at the attachment site. For example, as illustrated in the example in  FIG. 8 , in a state where the pressing cuff  26  sufficiently pressurized during the blood pressure measurement, the second electrode  31  is pressed toward the wrist H of the user with sufficient contact strength. Thus, as illustrated in the example in  FIG. 9 , relatively high stability is observed in the electrocardiographic waveform (second region A 2 ) based on the detection results, for example, during the pressurized state maintaining step, i.e. during the period from the end of the pressurizing step before the start of the depressurizing step for the pressing cuff  26 , and this electromagnetic waveform can be used as proper detection results. 
     In the present embodiment, the pressurized state maintaining step is provided between the pressurizing step and the depressurizing step for the pressing cuff  26 . The electrocardiographic waveform display data is generated that reflects the detection results from the detection circuit  32  during the pressurized state maintaining step. In the pressurized state maintaining step, the detection results are acquired from the detection circuit  32  in a state where the second electrode  31  is properly pressed against the skin at the attachment site of the user due to expansion of the pressing cuff  26 . In other words, according to the present embodiment, the state can be generated in which the electrocardiograph measurement electrodes are in proper contact with the attachment site of the user, and the electrocardiographic measurement can be performed with the electrocardiograph measurement electrodes in proper contact with the attachment site of the user. 
     In addition, in the present embodiment, the detection results are acquired from the detection circuit  32  during the period from the pressurizing step through the depressurizing step for the pressing cuff  26 . In addition, among the acquired detection results, the detection results that correspond to the pressurizing step and the depressurizing step for the pressing cuff  26  are determined to be noise. Then, the electrocardiographic waveform display data is generated using only the detection results excluding the detection results that correspond to the pressurizing step and the depressurizing step for the pressing cuff  26 . Thus, the display unit displays, as electrocardiographic measurement results, only the electrocardiographic data reflecting the detection results during the pressurized state maintaining step. Consequently, according to the present embodiment, the electrocardiographic waveform can be displayed that reflects only the detection results obtained while the electrocardiographic waveform is stable, that is, only the electrocardiographic data useful for diagnosis. 
     2.6 Modified Example 
     Note that the electrocardiographic measurement may be performed only in a state where the second electrode  31  of the blood pressure measurement device  10  is in proper contact with the attachment site of the user. In this modified example, the control unit  21  starts pressurizing the pressing cuff  26  without the supply of power to the first electrode  30  and the second electrode  31  or detection by the detection circuit  32 , for example. Then, for example, after the pressurization of the pressing cuff  26  is stopped, the display unit  25  is caused to display the instruction to the user to perform the electrocardiographic measurement operation. Then, based on the execution of the electrocardiographic measurement operation, the supply of power to the first electrode  30  and the second electrode  31  is started to start the detection by the detection circuit  32 . Then, based on the elapse of the electrocardiographic measurement time from the input of the electrocardiographic measurement operation, the supply of power to the first electrode  30  and the second electrode  31  is stopped and the depressurization of the pressing cuff  26  is started. 
     In the present modified example, the electrocardiographic measurement is started after the pressurization of the pressing cuff  26  is stopped, and the depressurization of the pressing cuff  26  is started after the elapse of the electrocardiographic measurement time. Thus, the detection results are acquired from the detection circuit  32  only during the period from after the stoppage of pressurization of the pressing cuff  26  before the start of the depressurization of the pressing cuff  26 . Accordingly, the detection results are acquired from the detection circuit  32  only in a state where the second electrode  31  is properly pressed against the skin at the attachment site of the user due to expansion of the pressing cuff  26 . Consequently, the electrocardiographic waveform display data can be generated using only the detection results obtained in a state where the electrocardiographic waveform is stable. According to the present modified example, the current for the electrocardiographic measurement flows through the user only during the time when the proper electrocardiographic measurement results can be acquired. Thus, the proper electrocardiographic waveform can be exclusively and effectively acquired without unnecessary extension of the time for which the current is flowing through the body of the user. This enables a reduction in physical burden on the user. 
     3. Common Configurations of Embodiments and the Like 
     A measurement device ( 1 : 10 ) includes a pressure acquisition unit ( 2 : 61 ) configured to acquire pressure information representing pressure in a pressing cuff, a cuff pressure control unit ( 3 : 63 ) configured to control, based on the pressure information, the pressure in the pressing cuff during each of a pressurizing step of pressurizing the pressing cuff, a pressurized state maintaining step of maintaining the pressing cuff in a pressurized state after end of the pressurizing step, and a depressurizing step of depressurizing the pressing cuff after end of the pressurized state maintaining step, a blood pressure calculation unit ( 4 : 62 ) configured to calculate a blood pressure of a user based on the pressure information, and an electrocardiographic measurement unit ( 5 : 65 ,  66 ) configured to measure an electrocardiogram of the user during the pressurized state maintaining step. 
     Note that the present invention is not limited to the embodiment, and various modifications can be made in an implementation stage without departing from the gist. Further, embodiments may be carried out as appropriate in a combination, and combined effects can be obtained in such case. Further, the various inventions are included in the embodiment, and the various inventions may be extracted in accordance with combinations selected from the plurality of disclosed constituent elements. For example, in a case where the problem can be solved and the effects can be obtained even when some constituent elements are removed from the entire constituent elements given in the embodiment, the configuration obtained by removing the constituent elements may be extracted as an invention. 
     Supplementary Notes 
     A part or the entirety of the embodiment can be described as described in the following supplementary notes in addition to the scope of the claims, but the present invention is not limited thereto. 
     (Supplementary Note 1) 
     A measurement device including a hardware processor ( 21 ) and a memory ( 22 ), wherein the hardware processor ( 21 ) is configured to 
     acquire pressure information representing pressure in a pressing cuff and cause the memory ( 22 ) to store the pressure information being acquired,
 
control, based on the pressure information stored in the memory ( 22 ), the pressure in the pressing cuff during each of a pressurizing step of pressurizing the pressing cuff, a pressurized state maintaining step of maintaining the pressing cuff in a pressurized state after end of the pressurizing step, and a depressurizing step of depressurizing the pressing cuff after end of the pressurized state maintaining step,
 
calculate a blood pressure of a user based on the pressure information stored in the memory ( 22 ), and cause the memory ( 22 ) to store the blood pressure being calculated, and
 
measure an electrocardiogram of the user during the pressurized state maintaining step, and cause the memory ( 22 ) to store the electrocardiogram being measured.
 
     REFERENCE SIGNS LIST 
     
         
           1  Blood pressure measurement device 
           2  Pressure acquisition unit 
           3  Pressing cuff control unit 
           4  Blood pressure calculation unit 
           5  Electrocardiographic measurement unit 
           6  Output unit 
           10  Blood pressure measurement device 
           11  Portable terminal 
           12  Physician terminal 
           13  Server 
           21  Control unit 
           22  Storage unit 
           23  Communication unit 
           24  Operation unit 
           25  Display unit 
           26  Pressing cuff 
           27  Pump 
           18  Pressure sensor 
           29  Battery 
           30 ,  31  Electrode 
           32  Detection circuit 
           32  Body 
           41 A Front surface 
           41 B Rear surface 
           42  Belt 
           42 A Outward facing surface 
           42 B Inward facing surface 
           43  Cuff unit 
           43 A Outward facing surface 
           43 B Inward facing surface 
           44 ,  45  Conductor 
           46  Push button 
           47 ,  48  Belt portion 
           61  Pressure acquisition unit 
           62  Blood pressure calculation unit 
           63  Pressing cuff control unit 
           64  Power control unit 
           65  Current acquisition unit 
           66  Electrocardiographic waveform generation unit 
           67  Output unit 
           71  Pressure information storage unit 
           72  Detection information storage unit 
           73  Blood pressure information storage unit 
           74  Electrocardiographic information storage unit 
           75  Setting information storage unit 
         A Electrocardiographic waveform