Patent Publication Number: US-11647912-B2

Title: Blood pressure measuring device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a Continuation Application of PCT application No. PCT/JP2018/046231, filed Dec. 17, 2018, which was published under PCT Article 21(2) in Japanese. 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2017-253040, filed Dec. 28, 2017, the entire contents of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     Field 
     The present invention relates to a blood pressure measuring device for the measurement of blood pressure. 
     Description of the Related Art 
     In recent years, a blood pressure measuring device for the use of blood pressure measurement has been utilized not only in medical facilities but also in households as a means to confirm health condition. A blood pressure measuring device measures blood pressure by detecting vibrations of an arterial wall, by, for example, wrapping a cuff around an upper arm, a wrist, or the like of a living body, inflating and deflating the cuff, and detecting the pressure of the cuff with the use of a pressure sensor. 
     For example, a so-called “integrated-type blood pressure measuring device”, in which a cuff and a device main body that supplies a fluid to the cuff are integrally formed, is known as the above-described blood pressure measuring device. In recent years, such an integrated-type blood pressure measuring device has faced requirements to be downsized to a wearable device that can be worn on a wrist. Therefore, the cuff used in the blood pressure measuring device has also faced downsizing requirements. 
     Such a blood pressure measuring device has a drawback in that the accuracy of the results of blood pressure measurement decreases when wrinkles, folds, or the like are generated in the cuff whose pressure is to be detected using a pressure sensor.  FIG.  23    shows an example of a cross-sectional image in which a blood pressure measuring device is worn on a wrist and a cuff is inflated. In the example shown in  FIG.  23   , when the blood pressure measuring device is worn on the wrist, wrinkles and folds are generated in the cuff so as to form a deep groove, and may divide the inner space of the cuff, as indicated by a portion X. In particular, as the cuff becomes smaller due to the downsizing of the blood pressure measuring device, the accuracy of the results of measurement of blood pressure may decrease. 
     A wearable device does not only pose problems when used for blood pressure measurement. It also poses problems when used, for example, as a biological information measuring device for the measurement of a pulse, etc., in that it cannot accurately measure a pulse. Accordingly, a technique in which an air cushion is provided to each of a first and second strap, in order to adjust a force of pulling a main body portion when the straps are wound around a measurement site, is known as a biological information measuring device capable of accurately measuring biological information such as a pulse, as disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2016-073338. Jpn. Pat. Appln. KOKAI Publication No. 2016-073338 discloses a technique for a biological information measuring device in which a pressure detector is provided in a range of a main body portion, where each force by which each strap pulls the main body portion affects the main body portion, a CPU adjusts the pulling force of each strap by an adjustment amount based on each pressure detected by the pressure detector and a relationship between the two pressures, and detection of a biological signal is commenced after the adjustment. 
     SUMMARY 
     The biological information measuring device disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2016-073338 is configured to detect biological information such as a pulse by receiving, at a light receiver, a reflection light reflected from a measurement target among the lights emitted from a light emitter. Therefore, the biological information measuring device is allowed to adjust the pulling force of each strap by adjusting the air cushion provided to each strap. 
     In the blood pressure measuring device, however, when the cuff is brought into close contact with a wrist by adjusting the pulling force of each strap, the cuff is partially pressed against the wrist, the device main body, and the like, and wrinkles or folds are likely to be generated in the cuff. 
     There are two arteries in the wrist, and a tendon between them; therefore, in the case of measuring blood pressure by compressing the region of the wrist where the arteries are present using the cuff, the pressure distribution of the tissues around the arteries varies when the region is compressed by the cuff. If the pressure distribution varies, correct pressure cannot be measured, and the extent of error in measurement results may increase. 
     As such, a technique that can suppress the generation of wrinkles, folds, and the like in a cuff is required of a blood pressure measuring device that measures blood pressure at a wrist. 
     According to one aspect, there is provided a blood pressure measuring device including: a holder configured to be mounted on a wrist of a living body and come into contact with a portion of the wrist at least between a dorsal side and a palmar side; a sensing cuff provided on a side of the holder nearer to the living body and arranged in a region of the wrist where arteries exist; and a cuff provided on a side of the holder nearer to the living body and arranged on the dorsal side of the wrist. 
     In this aspect, the “portion of the wrist at least between a dorsal side and a palmar side” refers to a region which is on a lateral side of the wrist between the dorsal side and the palmar side, and is located in a direction perpendicular to the direction of gravity when the arm is extended forward with the back of the hand facing upward and the palm of the hand facing downward. Furthermore, the “portion of the wrist at least between a dorsal side and a palmar side” means a region of the wrist located on an outer side of the radius and the ulna in the direction in which the radius and the ulna are aligned. Also, the region of the wrist where arteries exist includes a region on the palmar side of the wrist where exists the tendon approximately in the center, and covers two arteries adjacent to the tendon in the circumferential direction of the wrist. 
     The sensing cuff and the cuff are wrapped around the wrist when blood pressure is measured, and are inflated when a fluid is supplied thereto. Also, the sensing cuff and the cuff of this aspect include a bag-shaped structure such as an air bag. 
     According to this aspect, when the cuff is inflated in a state where the holder is in contact with the portion of the wrist between the dorsal side and the palmar side, the skin of the wrist in the region touched by the holder is pulled by the cuff together with the holder. Since the skin of the wrist on the palmar side is pulled thereby, sagging of the skin of the wrist on the palmar side, and the like are reduced, and the sensing cuff comes into close contact on its surface. As a result, it is not only possible to reduce variations in the pressure distribution of the region compressed by the sensing cuff that occur when the wrist is compressed, but also to suppress the generation of wrinkles and folds in the sensing cuff. 
     There is provided the blood pressure measuring device according to the above aspect, including a device main body, and a pressing cuff configured to press the sensing cuff, wherein the holder includes a strap provided to the device main body and a curler that is configured to bend along a circumferential direction of the wrist, has one end and another end separated from each other, and is configured to be fixed to the device main body to face the strap, wherein the pressing cuff and the sensing cuff are arranged in a position facing a region of the curler where the arteries exist. 
     According to this aspect, the blood pressure measuring device can prevent the sensing cuff from being wrinkled or folded by pressing the sensing cuff with the pressing cuff, and can reliably bring the strap and the curler as holders or the curler into contact with the portion of the wrist between the dorsal side and the palmar side by tightening the wrist with the strap and pressing the curler. 
     There is provided the blood pressure measuring device according to the above aspect, further including a back plate extending in a circumferential direction of the wrist, wherein the pressing cuff is provided on a side of the curler nearer to the living body, the back plate is provided on a side of the pressing cuff nearer to the living body, and the sensing cuff is provided on a side of the back plate nearer to the living body. 
     According to this aspect, since the back plate extending in the circumferential direction of the wrist is provided between the pressing cuff and the sensing cuff, the back plate transmits a pressing force from the pressing cuff to the sensing cuff in accordance with the shape of the wrist, thereby suppressing the generation of wrinkles and folds in the sensing cuff. 
     There is provided the blood pressure measuring device according to the above aspect, further including a flat plate provided between the curler and the pressing cuff and arranged in a region of the wrist where a tendon exists. 
     According to this aspect, the flat plate between the curler and the pressing cuff can press all three of the tendon of the wrist, the pressing cuff and the sensing cuff in the region where the tendon exists. Therefore, as the sensing cuff is pressed by the tendon, the generation of wrinkles and folds in the sensing cuff can be suppressed. 
     There is provided the blood pressure measuring device according to the above aspect, wherein the thickness of the cuff in a direction of inflating from the curler toward the wrist is larger than those of the pressing cuff and the sensing cuff. 
     According to this aspect, the strap and the curler deform in a direction in which the strap and the curler come into contact with the wrist by making the thickness of the cuff in the inflating direction be larger than those of the pressing cuff and the sensing cuff. Therefore, the strap and the curler come into close contact with the portion of the wrist between the dorsal side and the palmar side, and the skin of the wrist between the dorsal side and the palmar side is pulled. Thus, the skin of the wrist on the palmar side facing the sensing cuff is stretched, and the strap and the curler on the palmar side are pulled. As a result, the sensing cuff is in suitably close contact with the surface of the wrist on the palmar side, making it possible to further suppress the generation of wrinkles and folds in the sensing cuff. 
     The present invention can provide a blood pressure measuring device capable of suppressing the generation of wrinkles and folds in a sensing cuff. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of a configuration of a blood pressure measuring device according to a first embodiment of the present invention. 
         FIG.  2    is a perspective view of a configuration of the blood pressure measuring device. 
         FIG.  3    is an exploded view of a configuration of the blood pressure measuring device. 
         FIG.  4    is an explanatory diagram showing a state in which the blood pressure measuring device is worn on a wrist. 
         FIG.  5    is a block diagram showing a configuration of the blood pressure measuring device. 
         FIG.  6    is a perspective view of a configuration of a device main body and a curler of the blood pressure measuring device. 
         FIG.  7    is a perspective view of a configuration of the device main body of the blood pressure measuring device. 
         FIG.  8    is a plan view of an internal configuration of the device main body. 
         FIG.  9    is a plan view of an internal configuration of the device main body. 
         FIG.  10    is a plan view of a configuration of a cuff structure of the blood pressure measuring device. 
         FIG.  11    is a plan view of another configuration of the cuff structure of the blood pressure measuring device. 
         FIG.  12    is a cross-sectional view of configurations of a strap, the curler, and the cuff structure of the blood pressure measuring device. 
         FIG.  13    is a cross-sectional view of configurations of the curler and the cuff structure of the blood pressure measuring device. 
         FIG.  14    is an explanatory diagram showing a configuration of the blood pressure measuring device in which the blood pressure measuring device is worn on a wrist and the cuff structure is inflated. 
         FIG.  15    is a cross-sectional diagram schematically showing a configuration of the blood pressure measuring device in which the blood pressure measuring device is worn on a wrist and the cuff structure is inflated. 
         FIG.  16    is a flowchart showing an example of the use of the blood pressure measuring device. 
         FIG.  17    is a perspective diagram showing an example in which the blood pressure measuring device is worn on a wrist. 
         FIG.  18    is a perspective diagram showing an example in which the blood pressure measuring device is worn on a wrist. 
         FIG.  19    is a perspective diagram showing an example in which the blood pressure measuring device is worn on a wrist. 
         FIG.  20    is a plan view of a configuration of a cuff structure according to a second embodiment of the present invention in a state of being worn on a wrist. 
         FIG.  21    is a cross-sectional view of configurations of the strap, the curler, and the cuff structure of the blood pressure measuring device. 
         FIG.  22    is a cross-sectional diagram schematically showing a configuration of the blood pressure measuring device in which the blood pressure measuring device is worn on a wrist and the cuff structure is inflated. 
         FIG.  23    is a cross-sectional image showing an example in which a conventional blood pressure measuring device is worn on a wrist and a cuff is inflated. 
     
    
    
     DETAILED DESCRIPTION 
     First Embodiment 
     Hereinafter, an example of a blood pressure measuring device  1  according to a first embodiment of the present invention will be described with reference to  FIGS.  1  to  15   . 
       FIG.  1    is a perspective view of a configuration of the blood pressure measuring device  1  according to the first embodiment of the present invention with a strap  4  closed.  FIG.  2    is a perspective view of a configuration of the blood pressure measuring device  1  with the strap  4  opened.  FIG.  3    is an exploded view of a configuration of the blood pressure measuring device  1 .  FIG.  4    is an explanatory diagram showing a state in which the blood pressure measuring device  1  is worn on a wrist.  FIG.  5    is a block diagram showing a configuration of the blood pressure measuring device  1 .  FIG.  6    is a perspective view of configurations of a device main body  3  and a curler  5  of the blood pressure measuring device  1 .  FIG.  7    is a perspective view of a configuration of the device main body  3  of the blood pressure measuring device  1 , as viewed from a back cover  35  side.  FIGS.  8  and  9    are plan views of an internal configuration of the device main body  3 , as viewed from a windshield  32  side and the back cover  35  side, respectively.  FIG.  10    is a plan view of a configuration of a cuff structure  6  of the blood pressure measuring device  1 , as viewed from a sensing cuff  73  side.  FIG.  11    is a plan view of another configuration example of the cuff structure  6 , as viewed from the sensing cuff  73  side. 
       FIG.  12    is a cross-sectional diagram schematically showing configurations of the strap  4 , the curler  5 , and the cuff structure  6  of the blood pressure measuring device  1  taken along line XII-XII in  FIG.  10   .  FIG.  13    is a cross-sectional diagram schematically showing configurations of the curler  5  and the cuff structure  6  of the blood pressure measuring device  1  taken along line XIII-XIII in  FIG.  10   .  FIGS.  14  and  15    are explanatory diagrams respectively showing a configuration of the blood pressure measuring device  1 , in which the blood pressure measuring device  1  is worn on a wrist and the cuff structure  6  is inflated to measure blood pressure.  FIG.  15    is a cross-sectional view of a configuration of the blood pressure measuring device  1  when measuring blood pressure, taken along line XV-XV in  FIG.  10   . In  FIG.  12   , the strap  4 , the curler  5 , and the cuff structure  6  are schematically shown in a linear shape for convenience of explanation; however, these components are in a bent shape when provided in the blood pressure measuring device  1 . 
     The blood pressure measuring device  1  is an electronic blood pressure measuring device that is worn on a living body. In the present embodiment, an electronic blood pressure measuring device in the form of a wearable device worn on a wrist  200  of a living body will be described. As shown in  FIGS.  1  to  13   , the blood pressure measuring device  1  includes: the device main body  3 ; the strap  4 ; the curler  5 ; the cuff structure  6  with a pressing cuff  71 , a sensing cuff  73 , and a pulling cuff  74  that is fluidly continuous with the pressing cuff  71 ; and a fluid circuit  7 . In the present embodiment, the pulling cuff  74  is an example of the “cuff” of the present invention. 
     As shown in  FIGS.  1  to  13   , the device main body  3  includes a case  11 , a display  12 , an operation unit  13 , a pump  14 , a flow passage section  15 , an on-off valve  16 , a pressure sensor  17 , a power supply unit  18 , a vibration motor  19 , and a control substrate  20 . The device main body  3  is a supply device that supplies a fluid to the pressing cuff  71  by using the pump  14 , the on-off valve  16 , the pressure sensor  17 , the control substrate  20 , and the like. 
     The case  11  includes an outer case  31 ; a windshield  32  that covers an upper opening of the outer case  31 ; a base  33  provided in a lower part of the inside of the outer case  31 ; a flow passage cover  34  that covers a part of a back surface of the base  33 ; and a back cover  35  that covers a lower side of the outer case  31 . The case  11  also includes a flow passage tube  36  constituting a part of the fluid circuit  7 . 
     The outer case  31  is formed in a cylindrical shape. The outer case  31  includes: pairs of lugs  31   a  provided at symmetrical positions in the circumferential direction of the outer peripheral surface; and a spring rod  31   b  respectively provided between the paired lugs  31   a . The windshield  32  is a circular glass plate. 
     The base  33  holds the display  12 , the operation unit  13 , the pump  14 , the on-off valve  16 , the pressure sensor  17 , the power supply unit  18 , the vibration motor  19 , and the control substrate  20 . The base  33  forms a part of the flow passage section  15 . 
     The flow passage cover  34  is fixed to a back surface of the base  33 , which is an outer surface of the base  33  on the back cover  35  side. A groove is provided in one or both of the base  33  and the flow passage cover  34 , thereby forming a part of the flow passage section  15 . 
     The back cover  35  covers an end of the outer case  31  on the living body side. The back cover  35  is fixed to an end of the outer case  31  or the base  33  on the living body side by, for example, four screws  35   a  or the like. 
     The flow passage tube  36  forms a part of the flow passage section  15 . The flow passage tube  36  connects, for example, the on-off valve  16  and a part of the base  33  constituting the flow passage section  15 . 
     The display  12  is disposed on the base  33  of the outer case  31  and directly below the windshield  32 . The display  12  is electrically connected to the control substrate  20 . The display  12  is, for example, a liquid crystal display or an organic electroluminescence display. The display  12  displays various kinds of information including date and time, and measurement results of blood pressure values, such as systolic blood pressure and diastolic blood pressure, a heart rate, and the like. 
     The operation unit  13  is configured to allow a user to input a command. For example, the operation unit  13  includes: a plurality of buttons  41  provided to the case  11 ; a sensor  42  that detects an operation of the buttons  41 ; and a touch panel  43  provided to the display  12  or the windshield  32 . The operation unit  13  is operated by a user to convert a command into an electric signal. The sensor  42  and the touch panel  43  are electrically connected to the control substrate  20  and output an electric signal to the control substrate  20 . 
     For example, three buttons  41  are provided. The buttons  41  are supported by the base  33  and protrude from the outer peripheral surface of the outer case  31 . The plurality of buttons  41  and the plurality of sensors  42  are supported by the base  33 . For example, the touch panel  43  is provided integrally to the windshield  32 . 
     The pump  14  is, for example, a piezoelectric pump. The pump  14  compresses the air and supplies the compressed air to the cuff structure  6  via the flow passage section  15 . The pump  14  is electrically connected to the controller  55 . 
     The flow passage section  15  is an air flow passage formed of a groove or the like provided in the flow passage cover  34  that covers the back cover  35  side of the base  33  and the main surface of the base  33  on the back cover  35  side. The flow passage section  15  forms a flow passage leading from the pump  14  to the pressing cuff  71  and the pulling cuff  74 , and a flow passage leading from the pump  14  to the sensing cuff  73 . The flow passage section  15  also forms a flow passage leading from the pressing cuff  71  and the pulling cuff  74  to the atmosphere, and a flow passage leading from the sensing cuff  73  to the atmosphere. The flow passage cover  34  includes a connected portion  34   a  to which the pressing cuff  71  and the sensing cuff  73  or the pulling cuff  74  and the sensing cuff  73  are connected. The connected portion  34   a  is, for example, a cylindrical nozzle provided to the flow passage cover  34 . 
     The on-off valve  16  opens and closes a part of the flow passage section  15 . For example, a plurality of on-off valves  16  are provided, and selectively open and close the flow passage leading from the pump  14  to the pressing cuff  71  and the pulling cuff  74 ; the flow passage leading from the pump  14  to the sensing cuff  73 ; the flow passage leading from the pressing cuff  71  and the pulling cuff  74  to the atmosphere; and the flow passage leading from the sensing cuff  73  to the atmosphere, depending on the combination of the opening and closing of the on-off valves  16 . For example, two on-off valves  16  are used. 
     The pressure sensor  17  detects the pressure of the pressing cuff  71 , the sensing cuff  73 , and the pulling cuff  74 . The pressure sensor  17  is electrically connected to the control substrate  20 . The pressure sensor  17  is electrically connected to the control substrate  20 , converts the detected pressure into an electric signal, and outputs the electric signal to the control substrate  20 . For example, the pressure sensor  17  is provided in the flow passage leading from the pump  14  to the pressing cuff  71  and the pulling cuff  74 , and the flow passage leading from the pump  14  to the sensing cuff  73 . Since these flow passages are continuous with the pressing cuff  71 , the sensing cuff  73 , and the pulling cuff  74 , the pressures in these flow passages become the pressures in the internal spaces of the pressing cuff  71 , the sensing cuff  73 , and the pulling cuff  74 . 
     The power supply unit  18  is, for example, a secondary battery such as a lithium ion battery. The power supply unit  18  is electrically connected to the control substrate  20 . The power supply unit  18  supplies power to the control substrate  20 . 
     As shown in  FIGS.  5  and  8   , the control substrate  20  includes, for example, a substrate  51 , an acceleration sensor  52 , a communication unit  53 , a storage  54 , and a controller  55 . The control substrate  20  is configured by mounting the acceleration sensor  52 , the communication unit  53 , the storage  54 , and the controller  55  on the substrate  51 . 
     The substrate  51  is fixed to the base  33  of the case  11  by a screw or the like. 
     The acceleration sensor  52  is, for example, a three-axis acceleration sensor. The acceleration sensor  52  outputs, to the controller  55 , acceleration signals representing accelerations of the device main body  3  in three directions that are orthogonal to one another. For example, the acceleration sensor  52  is used to measure the amount of activity of the living body wearing the blood pressure measuring device  1  based on the detected accelerations. 
     The communication unit  53  is configured to be able to transmit and receive information to and from an external device in a wireless or wired manner. For example, the communication unit  53  transmits information controlled by the controller  55  and information such as measured blood pressure values, pulse, and the like to an external device via a network, and receives a program for software update, etc., from the external device via the network to transmit the program, etc., to the controller. 
     In the present embodiment, the network is, for example, the Internet, but is not limited thereto. The network may be a network such as a local area network (LAN) provided in a hospital, or direct communication with an external device using, for example, a cable having a terminal of a predetermined standard such as a USB may be adopted. Therefore, the communication unit  53  may include a plurality of wireless antennas, micro USB connectors, and the like. 
     The storage  54  stores in advance program data for controlling the entire blood pressure measuring device  1  and the fluid circuit  7 , setting data for the setting of various functions of the blood pressure measuring device  1 , calculation data for the calculation of blood pressure values and a pulse from a pressure measured by the pressure sensor  17 , and the like. The storage  54  also stores information such as measured blood pressure values and pulse. 
     The controller  55  is formed of one or more CPUs, and controls the operation of the entire blood pressure measuring device  1  and the operation of the fluid circuit  7 . The controller  55  is electrically connected to the display  12 , the operation unit  13 , the pump  14 , the on-off valves  16 , and the pressure sensors  17 , and supplies electric power. Also, the controller  55  controls the operations of the display  12 , the pump  14 , and the on-off valves  16  based on the electric signals output from the operation unit  13  and the pressure sensor  17 . 
     For example, the controller  55  includes a main CPU  56  that controls the operation of the entire blood pressure measuring device  1  and a sub-CPU  57  that controls the operation of the fluid circuit  7 , as shown in  FIG.  5   . For example, when a command to measure blood pressure is input from the operation unit  13 , the sub-CPU  57  drives the pump  14  and the on-off valves  16  to send compressed air to the pressing cuff  71  and the sensing cuff  73 . 
     The sub-CPU  57  also controls the driving and stoppage of the pump  14  and the opening and closing of the on-off valves  16  based on the electric signal output from the pressure sensor  17 , selectively sends compressed air to the pressing cuff  71  and the sensing cuff  73 , and selectively depressurizes the pressing cuff  71  and the sensing cuff  73 . The main CPU  56  obtains measurement results of blood pressure values, such as systolic blood pressure and diastolic blood pressure, a heart rate, and the like from the electric signal output from the pressure sensor  17 , and outputs an image signal corresponding to the measurement results to the display  12 . 
     As shown in  FIGS.  1  to  3   , the strap  4  includes a first strap  61  provided to one of the pairs of lugs  31   a  and the spring rod  31   b , and a second strap  62  provided to the other pair of lugs  31   a  and the spring rod  31   b . The strap  4  is wrapped around the wrist  200  via the curler  5 . 
     The first strap  61  is a so-called “parent” and is formed in a band shape. The first strap  61  includes a first hole  61   a  provided at one end and perpendicular to the longitudinal direction of the first strap  61 , a second hole  61   b  provided at the other end and perpendicular to the longitudinal direction of the first strap  61 , and a buckle  61   c  provided in the second hole  61   b . The first hole  61   a  has an inner diameter so that the spring rod  31   b  can be inserted thereinto and the first strap  61  can rotate with respect to the spring rod  31   b . That is, the first hole  61   a  is disposed between the paired lugs  31   a  and at the spring rod  31   b , so that the first strap  61  is rotatably held by the outer case  31 . 
     The second hole  61   b  is provided at a distal end of the first strap  61 . The buckle  61   c  includes a rectangular frame-shaped body  61   d  and a prodding stick  61   e  rotatably attached to the frame-shaped body  61   d . One side of the frame-shaped body  61   d  to which the prodding stick  61   e  is attached is inserted into the second hole  61   b , so that the frame-shaped body  61   d  is rotatably attached with respect to the first strap  61 . 
     The second strap  62  is a so-called “pointed end”, and formed in a band shape having a width that allows the second strap  62  to be inserted into the frame-shaped body  61   d . The second strap  62  includes a plurality of small holes  62   a  into which the prodding stick  61   e  is inserted. The second strap  62  also includes a third hole  62   b  provided at one end of the second strap  62  and perpendicular to the longitudinal direction of the second strap  62 . The third hole  62   b  has an inner diameter so that the spring rod  31   b  can be inserted thereinto and that the second strap  62  can rotate with respect to the spring rod  31   b . That is, the third hole  62   b  is disposed between the paired lugs  31   a  and at the spring rod  31   b , so that the second strap  62  is rotatably held by the outer case  31 . 
     The strap  4  described above forms an annular shape along the circumferential direction of the wrist  200  together with the outer case  31  as the second strap  62  is inserted into the frame-shaped body  61   d  and the prodding stick  61   e  is inserted into the small hole  62   a , thereby integrally connecting the first strap  61  and the second strap  62  to each other. 
     The curler  5  is made of a resin material. The curler  5  is formed in a band shape bent along the circumferential direction of the wrist. For example, one end and the other end of the curler  5  are separated from each other, and an outer surface of the curler  5  on the side of one end is fixed to the back cover  35  of the device main body  3 . One end of the curler  5  protrudes from the device main body  3 , and one end and the other end of the curler  5  are adjacent to each other. 
     As a specific example, the curler  5  has a shape bent along the circumferential direction of the wrist  200 , for example, in a side view from a direction perpendicular to the circumferential direction of the wrist, in other words, the longitudinal direction of the wrist, as shown in  FIGS.  1  to  3    and  FIG.  6   . For example, the curler  5  extends from the device main body  3  to the palmar side of the wrist  200  through the dorsal side of the wrist  200  and one side of the wrist  200 , and extends to the other side of the wrist  200 . That is, the curler  5  bends along the circumferential direction of the wrist and thereby extends over most parts of the wrist  200  in the circumferential direction of the wrist  200 , and both ends of the curler  5  are separated from each other by a predetermined interval. 
     The curler  5  has a hardness encompassing both flexibility and shape-retaining capability. The “flexibility” means that the curler  5  deforms in the radial direction when an external force is applied to the curler  5 , and means that when the curler  5  is pressed by the strap  4 , for example, the curler  5  deforms so as to approach the wrist, conform to the shape of the wrist, or trace the shape of the wrist, as viewed from a side of the curler  5 . The “shape-retaining capability” means that the curler  5  can maintain a pre-formed shape when no external force is applied thereto; and in the present embodiment, it means that the curler  5  can maintain a shape bent along the circumferential direction of the wrist. The curler  5  is made of a resin material. For example, the curler  5  is made of polypropylene and has a thickness of about 1 mm. The curler  5  holds the cuff structure  6  along the inner surface shape of the curler  5 . 
     As shown in  FIGS.  1  to  4  and  10  to  15   , the cuff structure  6  includes the pressing cuff  71 , the back plate  72 , the sensing cuff  73 , the pulling cuff  74 , and the flat plate  75 . 
     The cuff structure  6  is fixed to the curler  5 . The cuff structure  6  is configured so that the pressing cuff  71 , the back plate  72 , the sensing cuff  73 , and the flat plate  75  are stacked on the curler  5 , and that the pulling cuff  74  is disposed on the curler  5  in a manner that is separated from the pressing cuff  71 , the back plate  72 , the sensing cuff  73 , and the flat plate  75 . 
     As a specific example, the cuff structure  6  is configured so that the pressing cuff  71 , the back plate  72 , the sensing cuff  73 , the pulling cuff  74 , and the flat plate  75  are disposed on the inner surface of the curler  5 . The cuff structure  6  is configured so that the flat plate  75 , the pressing cuff  71 , the back plate  72 , and the sensing cuff  73  are stacked on the inner surface of the curler  5  on the palmar side of the wrist  200  in the mentioned order from the inner surface of the curler  5  toward the living body side, to be fixed. Also, the cuff structure  6  is configured so that the pulling cuff  74  is disposed on the inner surface of the curler  5  on the dorsal side of the wrist  200 . Each member of the cuff structure  6  is fixed to a member adjacent thereto by a double-sided tape, an adhesive, or the like. 
     The pressing cuff  71  is fluidly connected to the pump  14  via the flow passage section  15 . The pressing cuff  71  is inflated to press the back plate  72  and the sensing cuff  73  toward the living body. The pressing cuff  71  includes a plurality of, for example, two layers of air bags  81 . 
     The air bag  81  is a bag-shaped structure. Since the blood pressure measuring device  1  is configured to use the air with the pump  14  in the present embodiment, an air bag will be described. However, when a fluid other than the air is used, the bag-shaped structure may be a fluid bag such as a liquid bag. The plurality of air bags  81  are stacked and fluidly communicate with each other in the stacking direction. 
     The two layers of air bags  81  are formed in a rectangular shape elongated in one direction. The air bag  81  is formed by, for example, combining two sheet members  86  elongated in one direction and welding the edges thereof by heat. As a specific example, the two layers of air bags  81  include, from the living body side: a first sheet member  86   a ; a second sheet member  86   b  forming the first layer of air bag  81  with the first sheet member  86   a ; a third sheet member  86   c  integrally bonded to the second sheet member  86   b ; and a fourth sheet member  86   d  forming the second layer of air bag  81  with the third sheet member  86   c , as shown in  FIGS.  10  to  12   . 
     The first sheet member  86   a  and the second sheet member  86   b  form the air bag  81  by the welding of the peripheral edges of the four sides of the sheet members. The second sheet member  86   b  and the third sheet member  86   c  are disposed to face each other, and each include a plurality of openings  86   b   1  and  86   c   1  that fluidly connect the two air bags  81 . The fourth sheet member  86   d  has an adhesive layer or a double-sided tape on the outer surface thereof on the flat plate  75  side, and is attached to the flat plate  75  by the adhesive layer or the double-sided tape. 
     The third sheet member  86   c  and the fourth sheet member  86   d  form the air bag  81  by the welding of the peripheral edges of the four sides of the sheet members. 
     The back plate  72  is attached to the outer surface of the first sheet member  86   a  of the pressing cuff  71  by an adhesive layer, a double-sided tape, or the like. The back plate  72  is made of a resin material and formed in a plate shape. For example, the back plate  72  is made of polypropylene and formed in a plate shape having a thickness of about 1 mm. The back plate  72  has shape traceability. 
     The “shape traceability” refers to a function that allows the back plate  72  to deform so as to trace the shape of a contacted portion of the wrist.  200  to be placed; the “contacted portion of the wrist  200 ” refers to a region that comes into contact with the back plate  72 ; and the “contact” includes both direct and indirect contact. 
     For example, the back plate  72  includes a plurality of grooves  72   a  on both main surfaces of the back plate  72  at positions facing each other and at equal distances in the longitudinal direction of the back plate  72 . As a result, the portion of the back plate  72  having the grooves  72   a  is thinner than the portion of the back plate  72  without the grooves  72   a , and is thus easily deformed. Accordingly, the back plate  72  has shape traceability of deforming in accordance with the shape of the wrist  200  and extending in the circumferential direction of the wrist. The back plate  72  is formed to have a length covering the palmar side of the wrist  200 . The back plate  72  transmits the pressing force from the pressing cuff  71  to the main surface of the sensing cuff  73  on the back plate  72  side, in a state of conforming to the shape of the wrist  200 . 
     The sensing cuff  73  is fixed to the main surface of the back plate  72  on the living body side. As shown in  FIG.  14   , the sensing cuff  73  directly contacts the region of the wrist  200  where arteries  210  exist. The arteries  210  are a radial artery and an ulnar artery. The sensing cuff  73  is formed in the same shape as that of the back plate  72  or in a shape smaller than that of the back plate  72 , in the longitudinal direction and the width direction of the back plate  72 . The sensing cuff  73  is inflated to compress a region of the wrist  200  on the palmar side where the arteries  210  exist. The sensing cuff  73  is pressed toward the living body by the inflated pressing cuff  71  via the back plate  72 . 
     As a specific example, the sensing cuff  73  includes one air bag  91 , a tube  92  communicating with the air bag  91 , and a connector  93  provided at a distal end of the tube  92 . The sensing cuff  73  is configured so that one of the main surfaces of the air bag  91  is fixed to the back plate  72 . For example, the sensing cuff  73  is attached to the main surface of the back plate  72  on the living body side by a double-sided tape, an adhesive layer, or the like. 
     The air bag  91  is a bag-shaped structure. Since the blood pressure measuring device  1  is configured to use the air with the pump  14  in the present embodiment, an air bag will be described. However, when a fluid other than the air is used, the bag-shaped structure may be a liquid bag or the like. A plurality of air bags  91  described above are stacked and fluidly communicate with each other in the stacking direction. 
     The air bag  91  is formed in a rectangular shape elongated in one direction. The air bag  91  is formed by, for example, combining two sheet members elongated in one direction and the welding of the edges thereof by heat. As a specific example, the air bag  91  includes a fifth sheet member  96   a  and a sixth sheet member  96   b  from the living body side, as shown in  FIGS.  10  and  12   . 
     For example, the fifth sheet member  96   a  and the sixth sheet member  96   b  are configured so that the tube  92  fluidly continuous with the internal space of the air bag  91  is disposed on one side of the fifth sheet member  96   a  and the sixth sheet member  96   b , and is fixed by welding. For example, the fifth sheet member  96   a  and the sixth sheet member  96   b  form the air bag  91  by the welding of the peripheral edges of the four sides of the sheet members with the tube  92  disposed between the fifth sheet member  96   a  and the sixth sheet member  96   b , thereby integrally welding the tube  92  thereto. 
     The tube  92  is provided at one end in the longitudinal direction of the air bag  91 . As a specific example, the tube  92  is provided at an end of the air bag  91  close to the device main body  3 . The tube  92  includes a connector  93  at its distal end. The tube  92  forms a flow passage between the device main body  3  and the air bag  91  in the fluid circuit  7 . The connector  93  is connected to the connected portion  34   a  of the flow passage cover  34 . The connector  93  is, for example, a nipple. 
     The pulling cuff  74  is an example of the cuff. The pulling cuff  74  is fluidly connected to the pump  14  via the flow passage section  15 . The pulling cuff  74  is inflated to press the curler  5  away from the wrist  200 , thereby pulling the strap  4  and the curler  5  toward the dorsal side of the wrist  200 . The pulling cuff  74  includes a plurality of, for example, six layers of air bags  101 , a tube  102  communicating with the air bags  101 , and a connector  103  provided at a distal end of the tube  102 . 
     The pulling cuff  74  is configured so that in the inflation direction, that is, in the direction in which the curler  5  and the wrist  200  face each other in the present embodiment, the thickness of the pulling cuff  74  at the time of inflation is larger than the thickness of the pressing cuff  71  in the inflation direction at the time of inflation and the thickness of the sensing cuff  73  in the inflation direction at the time of inflation. That is, the air bag  101  of the pulling cuff  74  has a layer structure larger in the number of layers than the air bag  81  of the pressing cuff  71  and the air bag  91  of the sensing cuff  73 , and the thickness of the pulling cuff  74  when inflated from the curler  5  toward the wrist  200  is larger than those of the pressing cuff  71  and the sensing cuff  73 . 
     The air bag  101  is a bag-shaped structure. Since the blood pressure measuring device  1  is configured to use the air with the pump  14  in the present embodiment, an air bag will be described. However, when a fluid other than the air is used, the bag-shaped structure may be a fluid bag such as a liquid bag. The plurality of air bags  101  are stacked and fluidly communicate with each other in the stacking direction. 
     The six layers of air bags  101  are formed in a rectangular shape elongated in one direction. The air bag  101  is formed by, for example, combining two sheet members  106  elongated in one direction and welding the edges thereof by heat. As a specific example, the six layers of air bags  101  include, from the living body side: a seventh sheet member  106   a ; an eighth sheet member  106   b ; a ninth sheet member  106   c ; a tenth sheet member  106   d ; an eleventh sheet member  106   e ; a twelfth sheet member  106   f ; a thirteenth sheet member  106   g ; a fourteenth sheet member  106   h ; a fifteenth sheet member  106   i ; a sixteenth sheet member  106   j ; a seventeenth sheet member  106   k ; and an eighteenth sheet member  106   l , as shown in  FIG.  13   . The six layers of air bags  101  are integrally formed by bonding the respective sheet members  106  by a double-sided tape, an adhesive, welding, or the like. 
     The seventh sheet member  106   a  and the eighth sheet member  106   b  form the first layer of air bag  101  by the welding of the peripheral edges of the four sides of the sheet members. The eighth sheet member  106   b  and the ninth sheet member  106   c  are disposed to face each other and integrally bonded. The eighth sheet member  106   b  and the ninth sheet member  106   c  include a plurality of openings  106   b   1  and  106   c   1  that fluidly connect adjacent air bags  101 . The ninth sheet member  106   c  and the tenth sheet member  106   d  form the second layer of air bag  101  by the welding of the peripheral edges of the four sides of the sheet members. 
     The tenth sheet member  106   d  and the eleventh sheet member  106   e  are disposed to face each other and integrally bonded. The tenth sheet member  106   d  and the eleventh sheet member  106   e  include a plurality of openings  106   d   1  and  106   e   1  that fluidly connect adjacent air bags  101 . The eleventh sheet member  106   e  and the twelfth sheet member  106   f  form the third layer of air bag  101  by the welding of the peripheral edges of the four sides of the sheet members. 
     The twelfth sheet member  106   f  and the thirteenth sheet member  106   g  are disposed to face each other and integrally bonded. The twelfth sheet member  106   f  and the thirteenth sheet member  106   g  include a plurality of openings  106   f   1  and  106   g   1  that fluidly connect adjacent air bags  101 . The thirteenth sheet member  106   g  and the fourteenth sheet member  106   h  form the fourth layer of air bag  101  by the welding of the peripheral edges of the four sides of the sheet members. 
     The fourteenth sheet member  106   h  and the fifteenth sheet member  106   i  are disposed to face each other and integrally bonded. The fourteenth sheet member  106   h  and the fifteenth sheet member  106   i  include a plurality of openings  106   h   1  and  106   i   1  that fluidly connect adjacent air bags  101 . The fifteenth sheet member  106   i  and the sixteenth sheet member  106   j  form the fifth layer of air bag  101  by the welding of the peripheral edges of the four sides of the sheet members. 
     The sixteenth sheet member  106   j  and the seventeenth sheet member  106   k  are disposed to face each other and integrally bonded. The sixteenth sheet member  106   j  and the seventeenth sheet member  106   k  include a plurality of openings  106   j   1  and  106   k   1  that fluidly connect adjacent air bags  101 . The seventeenth sheet member  106   k  and the eighteenth sheet member  106   l  form the sixth layer of air bag  101  by the welding of the peripheral edges of the sheet members to form a rectangular frame shape. Also, for example, the tube  102  fluidly continuous with the internal space of the air bag  101  is disposed on one side of the seventeenth sheet member  106   k  and the eighteenth sheet member  106   l , and is fixed by welding. For example, the seventeenth sheet member  106   k  and the eighteenth sheet member  106   l  form the air bag  101  by welding the peripheral edges of the sheet members to form a rectangular frame shape, with the tube  102  disposed between the seventeenth sheet member  106   k  and the eighteenth sheet member  106   l , thereby integrally welding the tube  102  thereto. 
     For example, the sixth layer of air bag  101  is integrally formed with the second layer of air bag  81  of the pressing cuff  71 . That is, the seventeenth sheet member  106   k  is integrally formed with the third sheet member  86   c , and the eighteenth sheet member  106   l  is integrally formed with the fourth sheet member  86   d.    
     More specifically, the third sheet member  86   c  and the seventeenth sheet member  106   k  form a rectangular sheet member elongated in one direction, and the eighteenth sheet member  106   l  and the fourth sheet member  86   d  form a rectangular sheet member elongated in one direction. These sheet members are overlapped with each other. One end side is welded in a manner to form a rectangular frame shape without welding a part of the side on the other end side, thereby forming the second layer of air bag  81  of the pressing cuff  71 ; and the other end side is welded in a manner to form a rectangular frame shape without welding a part of the side on one end side, thereby forming the sixth layer of air bag  101  of the pulling cuff  74 . Since a part of the sides of the second layer of air bag  81  and the sixth layer of air bag  101  opposed to each other is not welded, the second layer of air bag  81  and the sixth layer of air bag  101  are fluidly continuous with each other. 
     The tube  102  is connected to one of the six layers of air bags  101 , and is provided at one end in the longitudinal direction of the air bag  101 . As a specific example, the tube  102  is provided at an end on the curler  5  side of the six layers of air bags  101  and close to the device main body  3 . The tube  102  includes a connector  103  at its distal end. The tube  102  forms a flow passage between the device main body  3  and the air bag  101  in the fluid circuit  7 . The connector  103  is connected to the connected portion  34   a  of the flow passage cover  34 . The connector  103  is, for example, a nipple. 
     In the present embodiment, the configuration has been described in which a part of the pulling cuff  74  is integrally formed with the pressing cuff  71  so that the pulling cuff  74  is fluidly continuous with the pressing cuff  71 ; however, the present invention is not limited thereto. For example, the pulling cuff  74  may be formed separately from the pressing cuff  71  and be fluidly discontinuous with the pressing cuff  71 , as shown in  FIG.  11   . In such a configuration, the pulling cuff  74  may be further provided with a tube  82  and a connector  83  in a manner similar to the pressing cuff  71  and the sensing cuff  73 , and a flow passage for supplying a fluid to the pulling cuff  74 , a check valve, and a pressure sensor may be connected in the fluid circuit  7 . 
     The sheet members  86 ,  96 , and  106  forming the pressing cuff  71 , the sensing cuff  73 , and the pulling cuff  74  are made of a thermoplastic elastomer. For example, thermoplastic polyurethane resin (hereinafter referred to as “TPU”), vinyl chloride resin, ethylene-vinyl acetate resin, thermoplastic polystyrene resin, thermoplastic polyolefin resin, thermoplastic polyester resin, and thermoplastic polyamide resin may be used as the thermoplastic elastomer forming the sheet members  86 ,  96 , and  106 . TPU is preferably used as the thermoplastic elastomer. The sheet member may have a single-layer structure or a multi-layer structure. 
     The sheet members  86 ,  96 , and  106  are not limited to the thermoplastic elastomer, and may be a thermosetting elastomer such as silicone or a combination of a thermoplastic elastomer (for example, TPU) and a thermosetting elastomer (for example, silicone). 
     When a thermoplastic elastomer is used for the sheet members  86 ,  96 , and  106 , a molding method such as T-die extrusion molding or injection molding is adopted, and when a thermosetting elastomer is used for the sheet members  86 ,  96 , and  106 , a molding method such as mold casting molding is adopted. The sheet members are molded by the molding method and thereafter sized into a predetermined shape. Then, the sized pieces are bonded by adhesion, welding, or the like to form the bag-shaped structures  81 ,  91 , and  101 . As a bonding method, a high-frequency welder or laser welding is used when a thermoplastic elastomer is used, and a molecular adhesive is used when a thermosetting elastomer is used. 
     The flat plate  75  is provided so as to face a region of the wrist  200  where the tendon  220  exists, and is formed of a material having a hardness capable of indirectly pressing the tendon  220  via the sensing cuff  73  or the like. The flat plate  75  is formed of, for example, polypropylene. The flat plate  75  is fixed, by an adhesive, a double-sided tape, or the like, at a position on the inner surface of the curler  5  and facing the region of the wrist  200  where the tendon  220  exists. The flat plate  75  includes, for example, a first plate member  75   a  fixed to the curler  5  and a second plate member  75   b  fixed to the first plate member  75   a  and to which the fourth sheet member  86   d  is fixed. 
     The fluid circuit  7  is formed of the case  11 , the pump  14 , the flow passage section  15 , the on-off valve  16 , the pressure sensor  17 , the pressing cuff  71 , the sensing cuff  73 , and the pulling cuff  74 . Hereinafter, a specific example of the fluid circuit  7  will be described in which the two on-off valves  16  used in the fluid circuit  7  are referred to as a “first on-off valve  16 A” and a “second on-off valve  16 B”, and the two pressure sensors  17  used in the fluid circuit  7  are referred to as a “first pressure sensor  17 A” and a “second pressure sensor  17 B”. 
     As shown in  FIG.  5   , the fluid circuit  7  includes, for example, a first flow passage  7   a  which continues from the pump  14  to the pressing cuff  71  and the pulling cuff  74 , a second flow passage  7   b  which is formed by branching a middle portion of the first flow passage  7   a  and continues from the pump  14  to the sensing cuff  73 , and a third flow passage  7   c  which connects the first flow passage  7   a  and the atmosphere. The first flow passage  7   a  includes the first pressure sensor  17 A. The first on-off valve  16 A is provided between the first flow passage  7   a  and the second flow passage  7   b . The second flow passage  7   b  includes the second pressure sensor  17 B. The second on-off valve  16 B is provided between the first flow passage  7   a  and the third flow passage  7   c.    
     In the fluid circuit  7  described above, when the first on-off valve  16 A and the second on-off valve  16 B are closed, only the first flow passage  7   a  is connected to the pump  14 , and the pump  14  and the pressing cuff  71  are fluidly connected. In the fluid circuit  7 , when the first on-off valve  16 A is opened and the second on-off valve  16 B is closed, the first flow passage  7   a  and the second flow passage  7   b  are connected, and the pump  14  and the pulling cuff  74 , the pulling cuff  74  and the pressing cuff  71 , and the pump  14  and the sensing cuff  73  are fluidly connected. In the fluid circuit  7 , when the first on-off valve  16 A is closed and the second on-off valve  16 B is closed, the first flow passage  7   a  and the third flow passage  7   c  are connected, and the pressing cuff  71 , the pulling cuff  74 , and the atmosphere are fluidly connected. In the fluid circuit  7 , when the first on-off valve  16 A and the second on-off valve  16 B are opened, the first flow passage  7   a , the second flow passage  7   b , and the third flow passage  7   c  are connected, and the pressing cuff  71 , the sensing cuff  73 , the pulling cuff  74 , and the atmosphere are fluidly connected. 
     Next, an example of measurement of blood pressure values using the blood pressure measuring device  1  will be described with reference to  FIGS.  16  to  19   .  FIG.  16    is a flowchart showing an example of blood pressure measurement using the blood pressure measuring device  1 , and shows both the operation of a user and the operation of the controller  55 .  FIGS.  17  to  19    show an example in which the user wears the blood pressure measuring device  1  on the wrist  200 . 
     First, the user wears the blood pressure measuring device  1  on the wrist  200  (step ST 1 ). As a specific example, the user, for example, inserts one of the wrists  200  into the curler  5 , as shown in  FIG.  17   . 
     At this time, since the device main body  3  and the sensing cuff  73  are disposed at positions of the curler  5  opposed to each other in the blood pressure measuring device  1 , the sensing cuff  73  is disposed in a region of the wrist  200  on the palmar side where the arteries  210  exist. Thus, the device main body  3  and the pulling cuff  74  are disposed on the dorsal side of the wrist  200 . Next, the user passes the second strap  62  through the frame-shaped body  61   d  of the buckle  61   c  of the first strap  61  using the hand opposite to the hand on which the blood pressure measuring device  1  is placed, as shown in  FIG.  18   . Then, the user pulls the second strap  62 , brings the member on the inner peripheral surface side of the curler  5 , that is, the cuff structure  6 , into close contact with the wrist  200 , and inserts the prodding stick  61   e  into the small hole  62   a . As a result, the first strap  61  and the second strap  62  are connected, and the blood pressure measuring device  1  is worn on the wrist  200 , as shown in  FIG.  19   . 
     Next, the user operates the operation unit  13  to input a command corresponding to initiation of measurement of blood pressure values. The operation unit  13  in which the input operation of the command has been performed outputs an electric signal corresponding to initiation of measurement to the controller  55  (step ST 2 ). Upon receiving the electric signal, the controller  55 , for example, opens the first on-off valve  16 A and closes the second on-off valve  16 B, drives the pump  14 , and supplies compressed air to the pressing cuff  71 , the sensing cuff  73 , and the pulling cuff  74  through the first flow passage  7   a  and the second flow passage  7   b  (step ST 3 ). Thereby, the pressing cuff  71 , the sensing cuff  73 , and the pulling cuff  74  start to inflate. 
     The first pressure sensor  17 A and the second pressure sensor  17 B detect the pressures of the pressing cuff  71 , the sensing cuff  73 , and the pulling cuff  74 , and output electric signals corresponding to the detected pressures to the controller  55  (step ST 4 ). Based on the received electric signals, the controller  55  determines whether or not the pressures in the internal spaces of the pressing cuff  71 , the sensing cuff  73 , and the pulling cuff  74  reach a predetermined pressure for measuring blood pressure (step ST 5 ). For example, when the internal pressures of the pressing cuff  71  and the pulling cuff  74  do not reach the predetermined pressure and the internal pressure of the sensing cuff  73  reaches the predetermined pressure, the controller  55  closes the first on-off valve  16 A and supplies compressed air through the first flow passage  7   a.    
     When the internal pressures of the pressing cuff  71  and the pulling cuff  74  and the internal pressure of the sensing cuff  73  all reach the predetermined pressure, the controller  55  stops driving the pump  14  (YES in step ST 5 ). At this time, the pressing cuff  71  and the pulling cuff  74  are sufficiently inflated, and the inflated pressing cuff  71  presses the back plate  72 , as shown in  FIGS.  14  and  15   . Since the pulling cuff  74  presses the curler  5  in a direction away from the wrist  200 , the strap  4 , the curler  5 , and the device main body  3  move in a direction away from the wrist  200 , and as a result, the pressing cuff  71 , the back plate  72 , the sensing cuff  73 , and the flat plate  75  are pulled toward the wrist  200 . In addition, when the strap  4 , the curler  5 , and the device main body  3  move in a direction away from the wrist  200  due to the inflation of the pulling cuff  74 , the strap  4 , the curler  5 , and the device main body  3  move with the strap  4  and the curler  5  moving toward both sides of the wrist  200  to be in close contact with both sides of the wrist  200 . Therefore, the strap  4  and the curler  5  in close contact with the skin of the wrist  200  pull the skin on both sides of the wrist  200  toward the dorsal side. The curler  5  may be configured to indirectly contact the skin of the wrist  200  via the sheet members  86  and  106 , for example, as long as it can pull the skin of the wrist  200 . 
     Further, the sensing cuff  73  is supplied with a predetermined amount of air so that the internal pressure thereof becomes a pressure required for measuring blood pressure, becomes inflated, and is then pressed toward the wrist  200  by the back plate  72  pressed by the pressing cuff  71 . Therefore, the sensing cuff  73  presses the arteries  210  in the wrist  200  to occlude the arteries  210 , as shown in  FIG.  15   . 
     For example, the controller  55  controls the second on-off valve  16 B to repeatedly open and close the second on-off valve  16 B or adjust the opening degree of the second on-off valve  16 B, thereby increasing the pressure in the internal space of the pressing cuff  71 . Based on the electric signal output from the second pressure sensor  17 B in the pressurization process, the controller  55  obtains measurement results of blood pressure values, such as systolic blood pressure and diastolic blood pressure, a heart rate, and the like (step ST 6 ). The controller  55  outputs an image signal corresponding to the obtained measurement results to the display  12 . After the blood pressure measurement is completed, the controller  55  opens the first on-off valve  16 A and the second on-off valve  16 B. 
     Upon receiving the image signal, the display  12  displays the measurement results on a screen (step ST 7 ). The user checks the measurement results by viewing the display  12 . After the measurement is completed, the user removes the prodding stick  61   e  from the small hole  62   a , removes the second strap  62  from the frame-shaped body  61   d , and removes the wrist  200  from the curler  5 , thereby removing the blood pressure measuring device  1  from the wrist  200 . 
     In the blood pressure measuring device  1  according to the embodiment configured as described above, the pulling cuff  74  on the dorsal side of the curler  5  is inflated in a state where the strap  4  and the curler  5  as holders are in contact with the skin on both sides of the wrist  200  between the dorsal side and the palmar side. Therefore, in the blood pressure measuring device  1 , when the pulling cuff  74  is inflated in a state where the strap  4  and the curler  5  are in contact with the skin on both sides of the wrist  200 , the skin of the wrist  200  in the region contacted by the strap  4  and the curler  5  is pulled by the pulling cuff  74  together with the strap  4  and the curler  5 . Since the skin of the wrist  200  on the palmar side of the wrist  200  is pulled thereby, sagging of the skin on the palmar side of the wrist  200 , and the like are reduced, and the sensing cuff  73  comes into close contact with the skin on the palmar side of the wrist  200  on its surface. As a result, the blood pressure measuring device  1  can reduce variations in the pressure distribution of the region compressed by the sensing cuff  73  when the wrist  200  is compressed, and can also suppress the generation of wrinkles and folds in the sensing cuff  73 . 
     The blood pressure measuring device  1  can prevent the sensing cuff  73  from being wrinkled or folded by pressing the sensing cuff  73  with the pressing cuff  71 . Also, since the blood pressure measuring device  1  is configured to tighten the wrist  200  with the strap  4  and press the curler  5 , the strap  4  and the curler  5  as holders or the curler  5  come reliably into contact with both sides of the wrist  200 , therefore allowing the skin on both sides of the wrist  200  to be reliably pulled toward the dorsal side by the pulling cuff  74 . 
     Further, since the back plate  72  extending in the circumferential direction of the wrist is arranged between the pressing cuff  71  and the sensing cuff  73 , the back plate  72  transmits a pressing force from the pressing cuff  71  to the sensing cuff  73  in accordance with the shape of the wrist  200 , thereby suppressing the generation of wrinkles and folds in the sensing cuff  73 . 
     Since the flat plate  75  is provided between the curler  5  and the pressing cuff  71 , the flat plate  75  can press the pressing cuff  71 , the back plate  72 , and the sensing cuff  73  in the region of the wrist  200  where the tendon  220  exists, when the curler  5  is pulled toward the wrist  200  by the pulling cuff  74 . Accordingly, the blood pressure measuring device  1  can suppress the generation of wrinkles and folds in the sensing cuff  73  by pressing the sensing cuff  73  with the tendon  220 . 
     The blood pressure measuring device  1  is configured so that the thickness of the pulling cuff  74  in the inflation direction at the time of inflation is larger than the thickness of the pressing cuff  71  in the inflation direction at the time of inflation and the thickness of the sensing cuff  73  in the inflation direction at the time of inflation. With this configuration, when the pulling cuff  74  is inflated, it is possible to increase the amount of deformation of the strap  4  and the curler  5  in a direction in which the strap  4  and the curler  5  are in contact with both sides of the wrist  200 , when the strap  4  and the curler  5  are deformed in a direction away from the wrist  200 . As a result, the strap  4  and the curler  5  are in close contact with the portion of the wrist  200  between the dorsal side and the palmar side, and the skin on both sides of the wrist  200  between the dorsal side and the palmar side can be more reliably pulled toward the dorsal side. As a result, the skin of the wrist  200  on the palmar side facing the sensing cuff  73  is stretched, and the strap  4  and the curler  5  on the palmar side are pulled toward the wrist  200 . Accordingly, the sensing cuff  73  is in suitably close contact with the surface of the skin in the region on the palmar side of the wrist  200  where the arteries  210  exist, and it is possible to further suppress the generation of wrinkles and folds in the sensing cuff  73 . 
     As described above, according to the blood pressure measuring device  1  of the present embodiment, it is possible to suppress the generation of wrinkles and folds in the sensing cuff  73  by providing the pulling cuff  74  at a position facing the sensing cuff  73  of the curler  5 . 
     Second Embodiment 
     Next, a second embodiment of the blood pressure measuring device  1  will be described with reference to  FIGS.  20  to  22   . The blood pressure measuring device  1  does not include the flat plate  75  in the cuff structure  6 . That is, the configuration of the second embodiment is achieved by removing the flat plate  75  from the configuration of the blood pressure measuring device  1  of the first embodiment described above. Therefore, part of the configuration of the present embodiment identical to that of the blood pressure measuring device  1  of the first embodiment will be described using the same reference numerals, and the descriptions and figures thereof will be omitted as appropriate. 
     The blood pressure measuring device  1  according to the second embodiment exhibits the same effects as those of the blood pressure measuring device  1  according to the first embodiment, except those exhibited by the flat plate  75 , and can suppress the generation of wrinkles and folds in the sensing cuff  73  by providing the pulling cuff  74  at a position facing the sensing cuff  73  of the curler  5 . 
     The present invention is not limited to the embodiments described above. In the example described above, the blood pressure measuring device  1  includes the strap  4  and the curler  5  as holders. However, only the strap  4  may be provided, or the strap  4  and the curler  5  may be integrally formed. Also, the blood pressure measuring device  1  may be configured so that both the strap  4  and the curler  5  or only the curler  5  come(s) into contact with the wrist  200  at the time of blood pressure measurement. The curler  5  includes a member on the inner surface of the curler  5 . That is, the blood pressure measuring device  1  may be configured so that the strap  4 , the curler  5  or the member on the inner surface of the curler  5  can pull the skin of the wrist  200  when the pulling cuff  74  is inflated. 
     For example, in the blood pressure measuring device  1 , the timing of opening and closing the first on-off valve  16 A and the second on-off valve  16 B at the time of blood pressure measurement can be suitably set. The example in which the blood pressure measuring device  1  calculates blood pressure based on a pressure measured in the process of pressurizing the pressing cuff  71  is described above; however, the present invention is not limited thereto. The blood pressure measuring device  1  may calculate blood pressure in the depressurization process or calculate blood pressure in both the pressurization process and the depressurization process. 
     Also, the above-described example shows the configuration of the pressing cuff  71  in which the air bag  81  is formed of each sheet member  86 ; however, the present invention is not limited thereto. For example, the air bag  81  may further include another configuration in order to control deformation or inflation of the pressing cuff  71 . 
     Furthermore, in the above-described example, the back plate  72  includes the plurality of grooves  72   a ; however, the present invention is not limited thereto. For example, the number, depth, and the like of the grooves  72   a  of the back plate  72  can be suitably set in order to control the ease of deformation and the like, and the back plate  72  may include a member that suppresses deformation. 
     That is, the above-described embodiments are merely examples of the present invention in all respects. It goes without saying that various improvements and modifications can be made without departing from the scope of the present invention. In other words, in the implementation of the present invention, a specific configuration according to the embodiment may be adopted as appropriate. 
     REFERENCE SIGNS LIST 
     
         
         
           
               1 . Blood pressure measuring device 
               3 . Device main body 
               4 . Strap 
               5 . Curler 
               6 . Cuff structure 
               7 . Fluid circuit 
               7   a . First flow passage 
               7   b . Second flow passage 
               7   c . Third flow passage 
               11 . Case 
               12 . Display 
               13 . Operation unit 
               14 . Pump 
               15 . Flow passage section 
               16 . On-off valve 
               16 A. First on-off valve 
               16 B. Second on-off valve 
               17 . Pressure sensor 
               17 A. First pressure sensor 
               17 B. Second pressure sensor 
               18 . Power supply unit 
               19 . Vibration motor 
               20 . Control substrate 
               31 . Outer case 
               31   a . Lug 
               31   b . Spring rod 
               32 . Windshield 
               33 . Base 
               34 . Flow passage cover 
               34   a . Connected portion 
               35 . Back cover 
               35   a . Screw 
               36 . Flow passage tube 
               41 . Button 
               42 . Sensor 
               43 . Touch panel 
               51 . Substrate 
               52 . Acceleration sensor 
               53 . Communication unit 
               54 . Storage 
               55 . Controller 
               61 . First strap 
               61   a . First hole 
               61   b . Second hole 
               61   c . Buckle 
               61   d . Frame-shaped body 
               61   e . Prodding stick 
               62 . Second strap 
               62   a . Small hole 
               71 . Pressing cuff 
               72 . Back plate 
               72   a . Groove 
               73 . Sensing cuff 
               74 . Pulling cuff (cuff) 
               75 . Flat plate 
               75   a . First plate member 
               75   b . Second plate member 
               81 . Air bag 
               82 . Tube 
               83 . Connector 
               86 . Sheet member 
               86   a . First sheet member 
               86   b . Second sheet member 
               86   b   1 . Opening 
               86   c . Third sheet member 
               86   c   1 . Opening 
               86   d . Fourth sheet member 
               91 . Air bag 
               92 . Tube 
               93 . Connector 
               96 . Sheet member 
               96   a . Fifth sheet member 
               96   b . Sixth sheet member 
               101 . Air bag 
               102 . Tube 
               103 . Connector 
               106 . Sheet member 
               106   a . Seventh sheet member 
               106   b . Eighth sheet member 
               106   b   1 . Opening 
               106   c . Ninth sheet member 
               106   c   1 . Opening 
               106   d . Tenth sheet member 
               106   d   1 . Opening 
               106   e . Eleventh sheet member 
               106   e   1 . Opening 
               106   f . Twelfth sheet member 
               106   f   1 . Opening 
               106   g . Thirteenth sheet member 
               106   g   1 . Opening 
               106   h . Fourteenth sheet member 
               106   h   1 . Opening 
               106   i . Fifteenth sheet member 
               106   i   1 . Opening 
               106   j . Sixteenth sheet member 
               106   j   1 . Opening 
               106   k . Seventeenth sheet member 
               106   k   1 . Opening 
               1061 . Eighteenth sheet member 
               200 . Wrist 
               210 . Artery 
               220 . Tendon