the embodiments of this invention will be described with reference to the drawings described above . fig1 is a perspective view of a pulse wave detection device as a first embodiment of this invention . the pulse wave detection device 1 includes a pressure sensing unit 2 , which is in contact with a detection portion of a subject &# 39 ; s body ( such as the palm side of a wrist ) during detection , an air bag 3 , which presses the pressure sensing unit 2 on the detection portion , a clip portion 4 , which covers the air bag 3 from the outside , and a band 5 , which is used as a cuff for mounting the device on the wrist . this band 5 carries or contains the pressure sensing unit 2 , the air bag 3 , and the clip portion 4 . the clip portion 4 , as shown in fig2 includes a cylindrical clip base 4 a with an opening along its longitudinal direction , and a plate 4 b , which extends from one end of the clip base 4 a and bends toward the central axis of the cylinder of the cylindrical clip base 4 a . the clip base 4 a is covered by the band 5 , while the plate 4 b is exposed without any cover . the portion of the plate 4 b next to the clip base 4 a is a simple extension of the surface of the cylinder of the clip base 4 a , but the top portion of the plate 4 b is bent toward the central axis of the cylinder of the clip base 4 a . surface fasteners 6 , 7 are mounted on both ends of the band 5 so that the band 5 is fastened when the device is worn on a wrist . this pulse wave detection device has a main body 1 a , which includes the pressure sensing unit 2 , air bag 3 , clip base 4 a and the portion of the band 5 which carries or contains the aforementioned components of the device . the plate 4 b extends from the clip base 4 a toward the distal end of the hand of the subject wearing the pulse wave detection device 1 . the configuration of this embodiment , as well as of the other embodiments of this invention described below , makes it easier to mount the device on a wrist because of the unitary combination of the main body 1 a and the device for restricting the movement of a hand ( plate 4 b ), and yet ensures an accurate and stable detection of pulse wave . [ 0042 ] fig3 is a perspective view of a pulse wave detection device of a second embodiment of this invention , and fig4 is a cross - sectional view of the device shown in fig3 through the plane indicated by the arrow in fig3 . the portion denoted by reference numeral 4 c corresponds to the clip base 4 a of the first embodiment shown in fig1 and forms a casing for the main body 1 a of the pulse wave detection device . a plate 4 b extends from the casing 4 c toward the distal end of a hand wearing the pulse wave detection device and bends toward back side of the hand . the size and the shape of the plate 4 b are essentially the same as the plate shown in fig1 and 2 . one end of a band 5 a is fixed to the casing 4 c of the main body 1 a through an axis 8 of the casing 4 c , and the other end of the band 5 a has a surface fastener 7 , which engages with a surface fastener 9 mounted on the casing 4 c . the pulse wave detection device of the second embodiment is mounted on a wrist of a subject so that the plate 4 b is , as shown in fig5 in direct contact with the palm ( a ) side of the hand through a proper adjustment of the band 5 a and the fasteners 7 , 9 . the rotation of the wrist joint is restricted during detection , since the main body 1 a and the plate 4 b hinder the movement of the hand relative to the wrist portion . similarly , the pulse wave detection device of the first embodiment shown in fig1 should be mounted on the wrist of a subject so that the plate 4 b is in direct contact with the palm side of the subject &# 39 ; s hand . [ 0044 ] fig6 is a schematic view of a pulse wave detection device of a third embodiment of this invention . a plate 4 b extends from the main body 1 a toward the distal end of the hand , and bends toward the back ( b ) side of the hand . although it is not shown in fig6 plate 4 b is connected to and supported by the main body 1 a . the pulse wave detection device of the third embodiment is mounted on the wrist so that the plate 4 b is in direct contact with the back side of the hand . [ 0045 ] fig7 is a schematic view of a pulse wave detection device of a fourth embodiment of this invention . this device has two plates 4 b 1 , 4 b 2 , extending toward the distal end of the hand . plate 4 b 1 on the back ( b ) side of the hand extends from the band 5 a , and 4 b 2 on the palm ( a ) side extends from the main body 1 a . the device is mounted on the wrist so that plate 4 b 1 is in direct contact with the back side of the hand and plate 4 b 2 is in direct contact with the palm of the hand . this configuration ensures more stable detection of the pulse wave because the movement of the hand is restricted by the two plates 4 b 1 , 4 b 2 on both sides of the hand . [ 0046 ] fig8 is a schematic view of a pulse wave detection device of a fifth embodiment of this invention . this device includes a band 10 , which is connected to the plate 4 b at its distal end and is used for tying the palm or fingers to the plate 4 b , in addition to the band 5 a used for mounting the device on the wrist . when a subject wears the device of the fifth embodiment on his or her wrist , the subject or another person first temporarily mounts the main body la of the pulse wave detection device on the wrist so that the plate 4 b is in direct contact with the palm ( a ) of the hand on which the band 5 a is mounted , then adjusts the position of the plate 4 b relative to the hand , ties the palm or fingers to the plate 4 b using the band 10 , and finally tightly mounts the device on the wrist . in this fifth embodiment , the movement of the hand and the rotation of the wrist joint are further restricted because the hand is tied to the plate 4 b using the belt 10 . [ 0047 ] fig9 is a schematic view of a pulse wave detection device of a sixth embodiment of this invention . this device includes a marking 11 for positioning the fingers , which is formed on the upper surface of the plate 4 b at its distal end . the plate 4 b extends from the main body 1 a and has the marking along the center line of the plate 4 b . when the marking 11 coincides with the center line of the middle finger of the hand , as shown in fig9 the pressure sensing unit 2 is placed at or near the artery of the wrist for pulse wave detection . this configuration ensures pulse wave detection of high accuracy by adjusting the mounting of the main body 1 a with the band 5 a so that the marking 11 lies on the line running through the center of the middle finger . [ 0048 ] fig1 is a schematic view of a pulse wave detection device of a seventh embodiment of this invention . as in the case of the fifth embodiment , this device includes a band 10 which is connected to the plate 4 b at its distal end and is used for tying the palm or fingers to the plate 4 b , in addition to the band 5 a used for mounting the device on the wrist . similarly , the movement of the hand and thus the rotation of the wrist joint are further restricted with the hand being fixed to the plate 4 b . in this embodiment , one end of the band 10 is fixed on the upper surface of the plate 4 b at its distal end . a marking 11 is formed for the alignment of the middle finger , and serves the same purpose as the marking 11 of the sixth embodiment shown in fig9 . as shown in fig1 , the band 10 of the seventh embodiment has a hole 12 for receiving the thumb when the band 10 is wrapped around the hand for tying it to the plate 4 b . when a subject of detection wears this device , he or she first puts the main body 1 a on the wrist so that the plate 4 b is in direct contact with the palm ( a ) of the hand , puts the thumb through the hole 12 , grabs the plate 4 b with the thumb through the hole 12 , and adjusts the alignment between the marking 11 and the middle finger so that a proper positioning of the device relative to the hand is secured by fastening the two bands 5 a , 10 . this configuration of the seventh embodiment ensures a reliable mounting of the pulse wave detection device even when the subject of detection wears the device by itself . as one modification of the embodiments ( 1 - 7 ) described above , the plate 4 b and clip base 4 a may be formed as two separate parts and integrally combined through a slide mechanism and fixation by a screw or other fastening structure . in this configuration , it is possible to adjust the length of the plate 4 b in accordance with the size of the hand of a subject of detection . [ 0051 ] fig1 is a perspective view of a pulse wave detection device of a eighth embodiment of this invention , and the fig1 is a perspective view of the device shown in fig1 cut along a direction parallel to the longitudinal direction of the device . [ 0052 ] fig1 shows a pulse wave detection device in which batteries 21 , a display unit 22 , an operation unit 23 , a circuit board 24 and a compressed air manipulation system 25 including a pump and a pressure control valve are consolidated within the main body 1 a . in this configuration , the size and weight of the main body 1 a inevitably increase and thus result in a difficulty of mounting the device on the wrist because of an improper weight balance of the device and a high center of gravity position of the device . the portion indicated by the thick line in fig1 is the core of the device housing only the pressure sensing unit 2 and a pressurizing unit such as an air bag 3 . the eighth embodiment of this invention shown in fig1 and 12 is intended to solve the difficulty described in conjunction with the pulse wave detection device shown in fig1 . in the eighth embodiment , the plate 4 b of the clip portion 4 is formed as a casing having a storage area 26 for storing batteries 21 , a circuit board 24 and a compressed air manipulation system 25 . an operation unit 23 is formed on the top surface of the plate 4 b . the plate 4 b of this embodiment may be the plate 4 b of the second embodiment or any other embodiment described above . a display unit 22 is formed on the top surface of the main body 1 , though it may be formed on the top surface of the plate 4 b as well . this configuration reduces the size and weight of the main body 1 a by disposing in the plate 4 b all or a part of the components of the device described above , including the butteries 21 , the display unit 22 , the operation unit 23 , the circuit board 24 and the compressed air manipulation system 25 . as a result , the ease of mounting the device on a wrist improves because of the improved weight balance of the device . [ 0055 ] fig1 shows common components of blood pressure monitors described below as embodiments of this invention . a wrist blood pressure monitor 100 e includes a main body 101 containing a control device for controlling the blood pressure detection , and a cuff 102 for mounting the main body 101 on a wrist . the main body 101 has a display unit 103 and a start switch 104 on its top surface , and , as shown in fig1 , contains a pressure sensing unit 220 , a pump 222 for compressing the air , a deflation valve 224 and a cpu for controlling these components of the blood pressure monitor . the cuff 102 is a band 110 which has an air bag 109 therein for receiving compressed air sent form the pump 222 contained in the main body 101 and for pressurizing the artery of wrist during blood pressure detection . the band also has a surface fastener 111 for fastening the band 110 around the wrist . in the blood pressure detection , the pressure sensing unit 220 does not directly touch the wrist for detecting the pulse wave of the artery as is the case with the pulse wave detection device described above . rather , the pressure sensing unit 220 of the blood pressure monitor is placed between the air bag 109 and the deflation valve 224 . for measuring blood pressure , the air bag 109 is first filled with compressed air from the pump 222 for pressurizing the wrist portion until the artery is closed , the pumping is then stopped , and the deflation valve 224 is controlled by the cpu for slowly deflating the air bag 109 . during the release of the air from the air bag 109 , the pressure sensing unit 220 detects the pressure of the air bag 109 , which is a combination of the air pressure and pressure due to the pulse wave . the cpu derives the pulse wave component from the total pressure measured , and finds a maximum blood pressure when the pulse wave appears and a minimum blood pressure when the pulse wave disappears . as a modification , it is also possible to find the maximum and minimum blood pressure during the pressurization of the air bag 109 in a converse fashion . [ 0058 ] fig1 shows a cross - sectional view of the blood pressure monitor 100 e of fig1 , which is mounted on a wrist and has the air bag 109 filled with the compressed air for the detection . the main body 101 of the blood pressure monitor 100 e contains a pump 222 for generating the compressed air , a deflation valve 224 , and a pressure sensing unit 220 . the band 110 is fastened so that the air bag 109 is placed over the radialis 205 of the wrist portion for properly pressurizing the radialis 205 during detection . also shown in the figure are the radius 202 on the thumb side of the cross section , the ulna 203 on the little finger side , flexor digitorum profundus 204 a , palmaris longus 204 b , flexor digitorum superficialis 206 a , flexor carpi ulnaris 206 b , and the ulnaris 207 . if a hand is bent toward its palm side , as shown in fig1 , the tendons of the wrist move toward the skin as shown in fig1 . especially , the palmaris longus 204 b and the flexor carpi ulnaris 206 b rise in a large amount enough to push the skin upward . on the other hand , the radialis 205 and the ulnaris 207 are pushed down into the muscles . as a result , when a hand is bent toward its palm side during blood pressure detection , it is difficult to properly apply the pressure of the air bag 109 to the radialis 205 or the ulnaris 207 because of the tendons rising toward the skin . accordingly , accurate detection of blood pressure is not achieved . the following embodiments of this invention are directed to solving the aforementioned problem . fig1 is a schematic side view of a blood pressure monitor 100 a mounted on a wrist as a ninth embodiment of this invention , and fig1 is a schematic side view of the blood pressure monitor 100 a in which the main body of the device is moved toward the distal end of the hand . the wrist blood pressure monitor 100 a of the ninth embodiment has a main body 101 which is slidably mounted on a cuff 102 . the mechanism for moving the main body 101 toward the distal end of the hand ( the direction of the arrow s in fig1 ) is a slide rail 101 a provided between the main body 101 and the cuff 102 . it is also possible to use other slide mechanism known in the art including linear bearings to replace the slide rail 101 a as a means for moving the main body 101 in this embodiment . the main body 101 , when moved toward the distal end of the hand as shown in fig1 , serves as a regulating portion for restricting the movement of the hand . the range of motion of the hand is smaller when the main body 101 is moved ( a 2 in fig1 ) than it is when the main body 101 is positioned on the cuff ( a 1 in fig1 ). as a result , more accurate application of the air bag pressure to the artery is achieved when the main body is moved toward the distal end and thus prevents the hand from bending toward its palm side enough to allow the tendons to hinder blood pressure detection , for example . [ 0064 ] fig2 is a schematic side view of a blood pressure monitor 100 b mounted on a wrist as a tenth embodiment of the invention , and fig2 is a schematic plan view of the blood pressure monitor 100 b of fig2 mounted on the wrist of a subject . the wrist blood pressure monitor 100 b of the tenth embodiment has a guide portion 120 extending toward the distal end of the hand . this guide portion 120 may be made of a plastic material such as abs or polypropylene , and may be connected to either the main body 101 or the cuff 102 . the guide portion 120 serves as a regulating portion for restricting the movement of the hand . as a result , more accurate application of the air bag pressure to the artery is achieved because the guide portion 120 prevents the hand from bending toward its palm side enough to allow the tendons to hinder detection . the guide portion 120 may be detachably mounted on the blood pressure monitor 100 b , or it may be retractable into the blood pressure monitor 100 b itself . either configuration improves the handling of the blood pressure monitor 100 b during its mounting on and detaching from the wrist . [ 0067 ] fig2 is a schematic plan view of a blood pressure monitor 100 c mounted on a wrist as an eleventh embodiment of the invention , and fig2 is a schematic plan view of the device of fig2 in which a guide portion 120 is extended toward the distal end of the hand . the wrist blood pressure monitor 100 c of the eleventh embodiment has a guide portion 120 which is the same as the guide portion 120 of the tenth embodiment . however , the guide portion 120 of the eleventh embodiment is extended toward the distal end of the hand based on a slide mechanism in synchronization with the slide movement of the main body 101 toward the distal end . the slide mechanism of the ninth embodiment may be used in the eleventh embodiment . the blood pressure monitor 100 c also has a switching mechanism which activates the blood pressure monitor 100 c when the main body 101 is moved toward the distal end of the hand . the switching mechanism may be based on a pair of a detent and a projection formed between main body 101 and slide mechanism 101 a . the engagement of the detent and the projection , for example , switches on the blood pressure monitor 100 c , and disengagement of the detent and projection switches off the device . alternatively , the engagement may switch off the device and the disengagement switch on the device . other switching mechanisms known in the art may be applied to this embodiment . the guide portion 120 , which extends toward the distal end of the hand in synchronization with the slide movement of the main body 101 , serves as a regulating portion for restricting the movement of the hand . as a result , more accurate application of the air bag pressure to the artery is achieved because the guide portion 120 prevents the hand from bending toward its palm side enough to allow the tendons to hinder the detection . furthermore , the blood pressure monitor 100 c of the eleventh embodiment , which is switched on for the detection only when the main body 101 is moved toward the distal end of the hand , ensures that the regulating portion for restricting the movement of the hand ( the main body 101 or the guide portion 120 ) is always in place during the detection of blood pressure . in addition , this configuration eliminates the need for a start switch mounted on the top surface of the main body 101 , and thus makes it possible to have a larger display unit on the top surface of the main body 101 for better display of the information on the display unit , including measured blood pressure values . although the wrist blood pressure monitor of the eleventh embodiment has both the slide mechanism for the guide portion 120 in synchronization with the slide movement of the main body 101 and the switching mechanism in synchronization with the same movement , each of the two mechanisms may be provided separately for a blood pressure monitor . [ 0072 ] fig2 is a schematic side view of a blood pressure monitor 100 d mounted on a wrist as a twelfth embodiment of the invention , and fig2 is a schematic side view of the blood pressure monitor 100 d of fig2 in which a guide portion is rotated out toward the distal end of the hand . fig2 is a schematic plan view of the blood pressure monitor 100 d of fig2 . the main body 101 of the wrist blood pressure monitor 100 d of the eleventh embodiment can be rotated out toward the distal end of the hand from the cuff 102 . the rotating mechanism of the twelfth embodiment is a rotation axis 130 provided between the main body 101 and the cuff 102 . as shown in fig2 , the main body 101 is swung around the rotation axis 130 in the direction of r shown in the figure . the main body 101 , when rotated out toward the distal end of the hand as shown in fig2 , serves as a regulating portion for restricting the movement of the hand . the range of motion of the hand is smaller when the main body 101 is rotated out ( a 2 in fig2 ) than it is when the main body 101 is positioned on the cuff ( al in fig2 ). as a result , more accurate application of the air bag pressure to the artery is achieved when the main body is moved toward the distal end and prevents the hand from bending toward its palm side enough to allow the tendons to hinder the detection . the features described above of the embodiments of the blood pressure monitor of this invention may be selectively combined to provide a wrist blood pressure monitor . furthermore , although the whole main body is moved toward the distal end in the above embodiments , only a portion of the main body may be moved and a similar effect may be obtained for restricting the movement of the hand . although the embodiments are divided into those of a pulse wave detection device and those of a blood pressure monitor , the features described for the pulse wave detection device may be applicable to the blood pressure meter , and those for the blood pressure meter may be applicable to the pulse wave detection device , as long as the features meet the requirements of restricting the movement of hand of a particular device . for example , the plate for restricting the movement of hand of the first embodiment as a pulse wave detection device of this invention may be detachably mounted on the main body for the ease of mounting the device on the wrist , or may be extended toward the distal end of the hand for a better restriction of the movement of hand . likewise , a wrist blood pressure meter may have a plate extending from the main body for properly restricting the movement of hand for an accurate detection . the above is a detailed description of particular embodiments of this invention . it is recognized that departures from the disclosed embodiments may be made within the scope of the invention and that obvious modifications will occur to a person skilled in the art . the full scope of the invention is set out in the claims that follow and their equivalents . accordingly , the claims and specification should not be construed to narrow the full scope of protection to which the invention is entitled .
a vital sign detection device is mounted on the wrist of a subject for measurement of vital sign such as pulse wave and blood pressure and has a regulating portion for restricting the movement of the hand during a measurement . the regulating portion extends from a main body of the device toward the distal end of the hand , and may be a plate integral with the main body or the main body itself moved toward the distal end . when the device is used for the detection of pulse waves , the plate may have a band for tying the hand to the plate for preventing rotation of the wrist joint . when the device is used for the measurement of blood pressure , the main body of the device , which is slidably or rotatably transported toward the distal end , may suppress the movement of hand enough to prevent the rise of wrist tendons from hindering the measurement .