Abstract:
A first detector is provided with a cuff adapted to be placed on an upper arm of a subject to detect noninvasive blood pressure of the subject. At least one second detector is adapted to be placed on a part of the subject to detect at least one vital sign of the subject. A single main body is detachably provided on the cuff while being connected with the first detector and the at least one second detector. A display is provided on the main body and operable to display the non-invasive blood pressure and the at least one vital sign as measurement data. A transmitter is provided in the main body and operable to transmit the measurement data to a receiver placed in a remote location.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a vital sign telemeter serving as patient monitor for respectively determining and monitoring vital signals (vital signs), such as an electrocardiograph, respiration, blood pressure, body temperature, and oxygen saturation (SpO2) in blood, of a patient in a serious condition in an ICU, CCU, or an emergency room, a patient undergoing an operation, or a patient being in an emergency transportation, or a patient whose condition can change suddenly. 
     Nowadays, a vital sign telemeter of this type must be capable of simultaneous measurement of a number of measurement items (parameters); and a vital sign telemeter which is configured to be able to measure electrocardiogram, a respiration curve, body temperature, oxygen saturation (SpO2) in blood, non-invasive blood pressure (NIBP), or the like, as the first parameters has been proposed and put into practice. Furthermore, as functional configurations for a vital sign telemeter of this kind, the following are important: being compact, lightweight, and easily attachable to a patient (living body); display of processing results of vital sign data is easily viewed so that conditions of a patient can be recognized; capable of being operated for a long time with stability; providing highly reliable data and alarm; convenient to handle and operate; and the like. 
     There is known a vital sign telemeter, which is configured so as to measure vital signals (vital signs) constituted of a number of parameters; e.g., an electrocardiogram, impedance respiration, oxygen saturation (SpO2) in blood, and non-invasive blood pressure (NIBP); to receive the signals, and to process and display the signals as required vital sign data, has a large configuration, and has complicated signal wiring of sensors for measurement of the respective parameters. Accordingly, difficulty is encountered when a patient walks while wearing such a vital sign telemeter attached to an upper arm thereof, which poses restrictions on the patients activities. Namely, the vital sign telemeter has a drawback of sacrificing the patient&#39;s QOL (quality of life). 
     Furthermore, as equipment for measurement of a single vital signal as found in a blood pressure monitor, there is known equipment in which a cuff for measurement of blood pressure and a device configured to process a measured vital signal, thereby displaying the vital signal, are integrated to be attached to an upper arm of a patient or the like. However, as described hitherto, there has been neither suggested nor embodied a vital sign telemeter in which a detector, a processor and a display for vital signals constituted of a number of parameters as required vital signals are integrated, and configured to be attached to an upper arm of a patient, or the like, to thus enable monitoring of the patient at the patient&#39;s side or from a remote site in an easy and convenient manner. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the invention to provide a vital sign telemeter capable of being attached onto an upper arm of a patient while integrating a detector, a processor and a display for plural kinds of vital signs including at least blood pressure into a single unit. 
     It is also an object of the invention to provide a vital sign telemeter capable of executing safety operation even when a single fault condition in connection with the blood pressure measurement (specifically defined by IEC 60601-2-30 Ed. 2.0:1999 (en)) is established. 
     It is also an object of the invention to provide a vital sign telemeter which is convenient in handling so as to reduce the burden on a patient caused by applying the vital sign telemeter even if the above requirements are satisfied. 
     In order to achieve the above objects, according to the invention, there is provided a vital sign telemeter, comprising:
         a first detector, comprising a cuff adapted to be placed on an upper arm of a subject to detect non-invasive blood pressure of the subject;   at least one second detector, adapted to be placed on a part of the subject to detect at least one vital sign of the subject;   a single main body, detachably provided on the cuff while being connected with the first detector and the at least one second detector;   a display, provided on the main body and operable to display the non-invasive blood pressure and the at least one vital sign as measurement data; and   a transmitter, provided in the main body and operable to transmit the measurement data to a receiver placed in a remote location.       

     Preferably, at least one of the first detector and the at least one second detector is detachably connected to the main body. 
     Preferably, the at least one second detector includes at least one of: a plurality of electrodes, adapted to be attached on at least one of a chest and a limb of the subject to detect at least one of electrocardiogram and respiration of the subject; a sensor, adapted to be attached on a finger of the subject to detect oxygen saturation in blood of the subject; and a sensor, adapted to be attached on a face of the subject to detect a concentration of carbon dioxide in gas expired through nostrils of the subject. 
     With the above configuration, since the detectors for obtaining plural kinds of vital signs and the display for displaying the detected vital signs as the measurement data are integrated into the single main body attached on the cuff placed on the upper arm of the subject, it is convenient to handle so as to reduce burdens on the subject caused by applying the vital sign telemeter. 
     In addition, since the first detector and the at least one second detector are used as consumable components, it is advantageous that these consumable components can be replaced conveniently, and handling is easy. 
     Here, it is preferable that the display is so configured as to simultaneously display, as the measurement data, the noninvasive blood pressure, the oxygen saturation in blood, pulse rate, pulse wave, and an interval between periodic activation of the first detector. 
     Preferably, a face of the main body to be faced the upper arm is curved. 
     Preferably, a retainer detachably retains the main body on the cuff, and a cover sheet is provided on the cuff and configured to securely surround the main body retained on the cuff. 
     In this case, the maintenance of the main body can be facilitated by configuring the cuff and the main body detachably; and in that the patient&#39;s unusual feeling by applying the vital sign telemeter as medical equipment can be lessened by improving the fitting sense of the cuff. 
     Here, it is preferable that the retainer is disposed between the cuff and a face of the main body facing the upper arm so as to extend in a first direction which is perpendicular to a winding direction of the cuff; and a width of the retainer in a second direction which is perpendicular to the first direction is narrower than a width of the main body in the second direction. 
     In this case, since a gap is not allowed between the cuff and the arm, not only the cuff can be securely wound even around a thin arm, but also fitting feeling to the patient is enhanced; and since excess inflation of the cuff is eliminated, amplitude of a blood pressure signal is enlarged, whereby performance of blood pressure measurement can be enhanced. 
     Preferably, a first switch is adjacent to the display and adapted to be actuated to activate or deactivate the first detector; and a second switch is adjacent to the display and adapted to be actuated to determine an interval between periodic activation of the first detector. 
     Preferably, the transmitter transmits the measurement data in a wireless manner. 
     Preferably, a safety controller deflates the cuff when the first detector falls into a single fault condition which results in a failure in inflating operation of the cuff. 
     According to the invention, there is provided a telemeting method, comprising steps of:
         providing a first detector comprising a cuff adapted to be placed on an upper arm of a subject;   providing at least one second detector adapted to be placed on a part of the subject;   connecting the first detector and the at least one second detector to a single main body which is detachably provided on the cuff;   detecting non-invasive blood pressure of the subject through the first detector;   detecting at least one vital sign of the subject through the second detector;   displaying the non-invasive blood pressure and the at least one vital sign on a display provided on the main body, as measurement data; and   transmitting the measurement data to a receiver placed in a remote location.       

     According to the invention, there is also provided a telemeting system, comprising:
         a first detector, comprising a cuff adapted to be placed on an upper arm of a subject to detect non-invasive blood pressure of the subject;   a second detector, adapted to be placed on a finger of the subject to detect oxygen saturation in blood of the subject;   a single main body, detachably provided on the cuff while being connected with the first detector and the second detector;   a receiver, placed in a remote location from the main body and provided with an indicator; and   a transmitter, provided in the main body and operable to transmit the non-invasive blood pressure and the oxygen saturation in blood as measurement data to the receiver, wherein:   the transmitter transmits information indicating that the measurement data for the oxygen saturation is unreliable at least while the first detector detects the non-invasive blood pressure, to the receiver; and   the indicator indicates that the measurement data for the oxygen saturation received from the transmitter is unreliable when the receiver receives the information.       

     With the above configuration, since it is easily indicated that the SpO2 value obtained during the NIBP measurement is unreliable, the reliability of the vital sign telemeter can be enhanced. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above objects and advantages of the present invention will become more apparent by describing in detail preferred exemplary embodiments thereof with reference to the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of a vital sign telemeter according to a first embodiment of the invention, showing a state that the telemeter is attached onto a patients body; 
         FIG. 2  is a block diagram showing the system configuration of the vital sign telemeter; 
         FIG. 3  is a perspective view of the vital sign telemeter showing a state that the telemeter is separated from a cuff; 
         FIG. 4  is a top perspective view of the vital sign telemeter and connectors to be connected thereto; 
         FIG. 5  is a bottom perspective view of the vital sign telemeter and detectors to be connected thereto; 
         FIG. 6  is a perspective view of the cuff, showing a state before a retainer is attached; 
         FIG. 7  is a perspective view of the cuff, showing a state after the retainer is attached; 
         FIG. 8  is a plan view of the cuff shown in  FIG. 7 ; 
         FIG. 9  is a perspective view of the vital sign telemeter and the cuff showing a state before the vital sign telemeter is attached on the cuff; 
         FIG. 10  is a vertical section view showing an engagement structure between the vital sign telemeter and the retainer; 
         FIG. 11  is a perspective view of the vital sign telemeter and the cuff showing a state after the vital sign telemeter is attached on the cuff; 
         FIG. 12A  is a schematic view showing an applied state of the cuff to a patient a thin arm; 
         FIG. 12B  is a schematic view showing an applied state of the cuff to a patient having a thick arm; 
         FIG. 13  is an enlarged view of a display of the vital sign telemeter; 
         FIGS. 14 and 15  are enlarged views showing examples of contents displayed in the display; 
         FIG. 16  is a flowchart of a measuring operation program for vital signals executed by the vital sign telemeter; 
         FIG. 17  is a flowchart showing of a safety control action program executed by the vital sign telemeter; 
         FIGS. 18A and 18B  are flowcharts showing a program for performing communication control executed between the vital sign telemeter and a receiver; 
         FIG. 19  is a perspective view of the receiver, and 
         FIG. 20  is a perspective view of a vital sign telemeter according to a second embodiment of the invention, showing a state that the telemeter is attached onto a patient&#39;s body. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 
       FIG. 1  shows a vital sign telemeter  10  according to one embodiment of the invention comprises: a blood pressure detector  22  for detecting blood pressure by a cuff  20  placed around an upper arm of a patient P; an electrocardiogram and respiration detector  24  for detecting an electrocardiogram and respiration by attaching a plurality of electrodes  23   a ,  23   b ,  23   c  on a chest and/or a limb of the patient P; an SpO2 detector  26  for detecting oxygen saturation (SpO2) in blood by attaching a sensor probe  25  on a finger of the patient P; a main body  40  having a display  42  for processing and displaying vital signals detected and measured with use of the respective detector  22 ,  24 ,  26 , and a transmitter (unillustrated) for transmitting the vital signals to a remote location in a wireless manner. 
     The main body  40  of the vital sign telemeter  10  is configured so that the main body  40  is detachably integrated with the cuff  20 ; and so that electrode lead wires  27   a ,  27   b ,  27   c  for use in connecting the main body  40  with the respective electrodes  23   a ,  23   b ,  23   c  of the electrocardiogram and respiration detector  24 , and a sensor probe lead wire  28  for use in connecting the main body  40  with the sensor probe  25  of the SpO2 detector  26  are detachably connected to the main body  40 . Meanwhile, in  FIG. 1 , the main body  40  integrated with the cuff  20  is provided with a retainer  51  for use of securely retaining the main body  40  on the shoulder of the patient P, as required. 
       FIG. 2  shows a system configuration of the main body  40  of the vital sign telemeter  10 . More specifically, reference numeral  60  denotes a main controller,  62  denotes a battery power source, and  64  denotes an auxiliary controller. The main controller  60  is connected to a display controller  66  serving as the display  42  and to a transmission controller  68  serving as the transmitter, respectively, and is also connected to the auxiliary controller  64 . The display controller  66  and the transmission controller  68  are set to process vital signals detected by the detector  22 ,  24 ,  26  so as to display or transmit the vital signals. 
     In the vital sign telemeter  10 , a inflator  70 , a first deflator  71  and a first pressure detector  72 , and a second deflator  73  and a second pressure detector  74  are respectively connected to the cuff  20  serving as the blood pressure detector. Herein, the inflator  70  and the first deflator  71  are controlled by the main controller  60 , and blood pressure detected by the first pressure detector  72  is input to the main controller  60  by way of a multiplexer  75  and an A/D converter  76 . The second deflator  73  is controlled by the auxiliary controller  64 , and blood pressure detected by the second pressure detector  74  is input to the auxiliary controller  64  by way of an AND converter  77 . 
     Vital signals detected by the respective electrodes  23   a ,  23   b ,  23   c  serving as the electrocardiogram and respiration detector  24  are input to the main controller  60  by way of an amplifier  80 , a respiration detector  81 , the multiplexer  75 , and the A/D converter  76 . The vital signals detected by the respective electrodes  23   a ,  23   c  are supplied with timing signals for detection of impedance respiration, by the main controller  60  by way of a respiration exciter output  82 . 
     Furthermore, in a sensor  25  constituted of a light-emitting element  25   a  and a light-receiving element  25   b  serving as the SpO2 detector  26 , the light-emitting element  25   a  is subject to light emission control by the main controller  60  by way of a light emission controller  83 . A signal detected by the light-receiving element  25   b  is measured as oxygen saturation (SpO2) in blood by an SpO2 detector  84 , and input into the main controller  60  by way of the multiplexer  75  and the A/D converter  76 . 
       FIG. 3  is a view showing, in a separated state, the cuff  20  and the main body  40  of the vital sign telemeter  10 . Herein, as shown in  FIGS. 3 to 5 , the main body  40  has the display  42  at the upper center of the front face thereof, and a battery storage section  44  at the lower center of the front face. The back face of the main body  40  is formed into a curved shape so as to fit an upper arm of a patient during attachment. The display  42  comprises an LCD panel. In the vicinity of the display  42 , there is provided an NIBP measurement adjuster  43  including a measurement start/stop switch  43   a  and a measurement interval setting switch  43   b . A cover  45  is detachably provided on the battery storage section  44  (see  FIG. 4 ). 
     On the top face of the main body  40 , a power switch  46 , a connector  47  for measurement of electrocardiogram and respiration, and a connector  48  for measurement of NIBP are provided. A connector  53  provided with electrode lead wires  27   a ,  27   b ,  27   c  for measurement of the electrocardiogram and respiration can be detachably connected to the connector  47 , and a connector  52   a  provided with a cuff hose  52  can be detachably connected to the connector  48  (see  FIGS. 4 and 5 ). A connector  49  for measurement of oxygen saturation (SpO2) in blood is provided on the bottom face of the main body  40 . A connector  54  provided with a sensor probe lead wire  28  for measurement of SpO2 can be detachably connected to the connector  49  (see  FIG. 5 ). 
     Furthermore, a slit  55   a  is provided on the top face of the main body  40 , and a slit  55   b  is provided on the bottom face of the main body  40 . The slits  55   a ,  55   b  are for engagement with a retainer  32 , which will be described later, for use when the main body  40  is attached to the cuff  20  (see  FIGS. 4 and 5 ). 
     As shown in  FIGS. 6 and 7 , the retainer  32  is attached to a portion of the cuff  20  placed around an upper arm of a patient, in order to retain the main body  40  of the vital sign telemeter  10  on the cuff  20 . As shown in  FIG. 6 , slits  33   a ,  33   b  are provided on the cuff  20 , and the retainer  32  having engagement sections  32   a ,  32   b  on both ends is attached to the cuff  20  through the slits  33   a ,  33   b . As the result, attachment of the retainer  32  to the cuff  20  can be carried out in a convenient manner. 
     A sheet cover  30  for covering the main body  40  in an attached state is provided at a position corresponding to the position where the retainer  32  is provided. The sheet cover  30  comprises a cover body  30   a  with one end thereof being fixed on the cuff  20 , and a fitting piece  30   b  with one end thereof being fixed to the cuff  20 . On the cover body  30   a , there is provided a window  31  for allowing visual check of the display  42  in a case where the main body  40  is covered. Hook-and-loop fasteners F are provided on the other end of the cover body  30   a  and that of the fitting piece  30   b , whereby the cover body  30   a  and the fitting piece  30   b  can be joined to and separated from each other. 
     A size adjustment ring  29  is provided at one end  20   a  of the cuff  20 . Accordingly, by passing the size adjustment ring  29  through the other end  20   b  of the cuff  20 , a length of the cuff  20  placed around an upper arm of a patient can be adjusted as required. For this reason, another hook-and-loop fastener F for the purpose of fixedly connecting the other end  20   b  of the cuff  20  which has passed though the size adjustment ring  29  is provided on the inner face of the other end  20   b  of the cuff  20  as required. 
     Accordingly, the cuff  20  configured as has been described can be attached to an upper arm of a patient by being formed into a ring-shape as shown in  FIG. 8 ; and allows mounting of the main body  40  of the vital sign telemeter  10  by being provided with the retainer  32  and the sheet cover  30 . 
     Next, how to attach the main body  40  of the vital sign telemeter  10  onto the cuff  20  will be explained with reference to  FIGS. 9 and 11 . In this embodiment, the back face of the main body  40  formed into a curved shape is butted against the retainer  32  which is attached to the cuff  20  shown in hitherto described  FIGS. 5 and 6 , and the engagement sections  32   a ,  32   b  of the retainer  32  are engaged with the slits  55   a ,  55   b  (see  FIGS. 4 and 5 ) provided on the top face and the bottom face of the main body  40  (see  FIGS. 9 and 10 ). Thereafter, the front face of the main body  40  is covered with the sheet cover  30  in a surrounding manner, and fixed by the hook-and-loop fasteners F as required.  FIG. 11 , shows a state that the assembly of the vital sign telemeter  10  is completed. 
       FIG. 12A  shows an applied state of the cuff  20  attached to a patient having a thin arm.  FIG. 12B  shows an applied state of the cuff  20  attached to a patient having a thick arm. As shown in the drawings, the cuff  20  can be applied in such a manner as to fit an arm of each patient in terms of size, by adjusting the turning-up length of the other end  20   b  of the cuff, which is the length to be turned up after passing through the size adjustment ring  29 . 
       FIG. 13  shows an example display of the main body  40  of the vital sign telemeter  10 . More specifically, the display  42  can display a systolic blood pressure “SYS 120 mmHg”, a diastolic blood pressure “DIA 60 mmHg”, a mean blood pressure “MEAN (70) mmHg”, an SpO2 value “% SpO2 97”, a pulse rate “PR 80”, measurement interval “5 min”, and others, such as a bar graph indicating the pulse wave, marks for indicating the electrode removal, the residual amount of the battery, and the error condition or the like. 
     Meanwhile, the NIBP measurement can be started and stopped arbitrarily, by operating the measurement start/stop switch  43   a  in compliance with contents appearing on the display  42 . In addition, intervals of the NIBP measurement can be set to a desired value, by operating the measurement interval setting switch  43   b  in sequence of; e.g., “manual-5 minutes-10 minutes-30 minutes-60 minutes, etc.,” to thus select any one. 
       FIG. 14  shows an example display of the display  42  in a case where the cuff  20  is inflated manually.  FIG. 15  shows an example of the display  42  in a case where the measurement is completed. More specifically,  FIG. 14  shows a case where a cuff pressure “CUFF (180) mmHg” is displayed; and  FIG. 15  shows a case where a systolic blood pressure “SYS 128 mmHg”, a diastolic blood pressure “DIA 60 mmHg”, and a mean blood pressure “MEAN (80) mmHg” are respectively displayed. 
       FIG. 16  is a flowchart of measuring operation program for performing measurement of respective vital signals with use of the vital sign telemeter  10  attached to a patient. Hereinafter, operations of a measurement program will be described in connection with the system configuration of the vital sign telemeter  10  shown in  FIG. 2 . 
     For starting measurement of the respective vital signals of a patient the power switch  46  of the vital sign telemeter  10  is turned on (step S 1 ). Subsequently, initialization and zero-calibration of NIBP measurement are performed (step S 2 ), and the measurement start/stop switch  43   a  is operated. At this time, when measurement start by the measurement start/stop switch  43   a  is determined (step S 3 ), a pump action of the inflator  70  for supplying air pressure to the cuff  20  is started, and solenoid valves of the deflators  71 ,  73  are closed (step S 4 ). Thereafter, whether or not the pressure of the cuff  20  has settled in a prescribed pressure is determined (step- 5 ). When the pressure has settled in the prescribed pressure, pump action of the inflator  70  is stopped (step S 7 ). When the pressure has not settled in the prescribed pressure, whether or not the pressure exceeds a threshold pressure which has been set in advance is determined (step S 6 ). When the pressure has not exceeded the threshold pressure, reach for the prescribed pressure is rechecked; and when the pressure has exceeded the same, error processing ERR is executed. 
     When the pressure of the cuff  20  reaches the prescribed pressure and the pump action is stopped, whether or not the inflating time period is no greater than a prescribed value is determined (step S 8 ). When the inflating time period is no greater than the prescribed value, the solenoid valves of the deflators  71 ,  73  are opened for a prescribed time period, thereby exhausting air in the cuff  20  (step S 9 ). When the inflating time period exceeds the prescribed value, the error processing ERR is executed. 
     Next, whether or not two pulse beats have been detected is determined (step S 10 ). When detected, pulse pressure data detected at this time is stored (step S 12 ). When the two pulse beats have not been detected, whether or not the time period spent for the detection is no greater than a prescribed value for pulse wave detection is determined (step S 11 ). When the time period is no greater than the prescribed value, the pulse is rechecked; and when the time period has exceeded the prescribed value, the error processing ERR is executed. 
     When the pulse pressure data is stored in step S 12 , whether or not the time period spent for the measurement is no greater than a prescribed value is determined (step S 13 ). When the time period is no greater than the prescribed value, whether or not blood pressure can be computed is determined (step S 14 ). When it is determined that the blood pressure can be computed, the maximum value of the pulse pressure amplitude is obtained (step S 15 ). 
     When the time period spent for the measurement exceeds the prescribed value, the error processing ERR is executed; and when it is determined that the blood pressure cannot be computed, the routine is returned to step S 9 , thereby repeating the process to step S 14 . 
     Here, a pressure value of the cuff  20  when the pulse pressure has the maximum value is set as a mean blood pressure (step S 16 ). A pressure value of the cuff  20  higher than the value corresponding to the mean blood pressure when the pulse pressure has a half value of the maximum value is set as a systolic blood pressure (step S 17 ). A pressure value of the cuff  20  lower than the value corresponding to the mean blood pressure when the pulse pressure has a half value of the maximum value is set as a diastolic blood pressure (step S 18 ). Thereafter, whether or not the systolic blood pressure has been computed is determined (step S 19 ). When computed, the solenoid valves of the deflators  71 ,  73  are opened (step S 20 ); and computation result of the blood pressure values is displayed on the display  42  (step S 21 ), thereby terminating a single measurement. When the systolic blood pressure has failed in computation, the routine is returned to the step S 4 , thereby repeating the processing to step S 19 . 
     The error processing ERR is executed such that description of the error is displayed on the display  42  (step S 22 ); pump action of the inflator  70  is stopped (step S 23 ); and the solenoid valves of the deflators  71 ,  73  are opened (step S 24 ), thereby terminating the measurement (step S 25 ). Subsequent blood pressure measurement is performed by repeating the routine from step S 2  to step S 25  after a prescribed interval. 
       FIG. 17  shows a flowchart of a safety control action program executed when the vital sign telemeter  10  attached to a patient to measure NIBP falls into a single fault condition as specified in IEC 60601-2-30 Ed. 2.0:1999 (en). Concretely, the single fault condition is defined as any single defect which: a) results in a failure of an adjuster for pressure of the cuff; b) prevents deflation of the cuff within the prescribed time period; and c) results in a failure of the timing for inflating the cuff. 
     Hereinafter, details of the safety control action program will be described on the basis of a relation with the system configuration of the vital sign telemeter  10  shown in  FIG. 2 . 
     In  FIG. 17 , for starting measurement of the respective vital signals of a patient by the vital sign telemeter  10 , the power switch  46  is turned on (step S 31 ). Subsequently, initialization and zero calibration of NIBP measurement is performed (step S 32 ). Thereafter, whether or not the measurement start/stop switch  43   a  is operated, or whether or not the blood pressure is being measured with a prescribed measurement interval is determined (step S 33 ). When the blood pressure is being measured, the second pressure detector  74  determines whether or not a state where the cuff pressure is 300 mmHg or higher is continued for 15 seconds or longer is detected (step S 34 ). Incidentally, when the blood pressure is not being measured, the solenoid valve of the second deflator  73  is opened (step S 38 ), thereby terminating the measurement. At this time, when the above state is detected at step S 34 , in order to avert a danger, the solenoid valve of the second deflator  73  is opened (step S 38 ), thereby terminating the measurement immediately. 
     When the above state is not detected at step S 34 , the second pressure detector  74  determines whether or not the cuff pressure has reached 330 mmHg or higher is detected (step S 35 ). When the above state is detected at step S 35 , in order to avert a danger, the solenoid valve of the second deflator  73  is opened (step S 38 ), thereby terminating the measurement immediately. 
     On the other hand, when the above state is not detected at step S 35 , the second pressure detector  74  determines whether or not a state where the cuff pressure is 15 mmHg or higher continues for 180 seconds or longer is detected (step S 36 ). At this time, when the above state is detected at step S 36 , in order to avert a danger, the solenoid valve of the second deflator  73  is opened (step S 38 ), thereby terminating the measurement. When the above state is not detected at step S 36 , the blood pressure measurement is performed by the second pressure detector  74  while closing the solenoid valve of the second deflator  73  (step S 37 ). In this case, the main controller  60  drives the inflator  70  to measure blood pressure with the first pressure detector  72 . At the same time, the main controller  60  sends a signal indicating that the blood pressure measurement is now performed to the auxiliary controller  64 , thereby the auxiliary controller  64  recognizes that the blood pressure measurement is executed by the main controller  60 . 
       FIGS. 18A and 18B  are flowcharts of a communication control program for controlling transmission of vital signals measured by attaching the vital sign telemeter  10  to a patient; and for controlling receipt of the vital signals at a remote location. Hereinafter, details of the communication control program will be described on the basis of a relation with the system configuration of the vital sign telemeter  10  shown in  FIG. 2 . 
     For starting transmission control in the transmission controller  68 , as shown in  FIG. 18A , the power switch  46  is turned on (step S 41 ). Electrocardiogram waveform data, pulse waveform data, respiratory waveform data obtained by the electrocardiogram and respiration detector  24 , and SpO2 data obtained by the SpO2 detector  26  are then respectively transmitted to a receiver (step S 42 ). Subsequently, when it is detected measurement start by the actuation of the measurement start/stop switch  43   a  (step S 43 ), a pump action of an inflator  70  for supplying air to the cuff  20  is started, and solenoid valves of the deflators  71 ,  73  are closed, whereby NIBP measurement is started (step S 44 ). Upon start of the NIBP measurement, a measurement flag indicating that the blood pressure is being measured is transmitted to the receiver (step S 45 ). 
     During the period during which blood pressure is being measured, whether or not an error has been found is determined (step S 46 ). When no error has been found, data obtained by the NIBP measurement are transmitted to the receiver (step S 47 ). Thereafter, transmission of the measurement flag is stopped, and a completion flag indicating that the blood pressure measurement is completed is transmitted to the receiver (step S 48 ). In addition, when an error has been found during the period during which blood pressure is being measured, an error flag is transmitted to the receiver (step S 49 ). 
     By the way, since the blood flow is stopped by the inflated cuff  20 , the measured SpO2 value may be unreliable during the NIBP measurement. Accordingly, in this embodiment, the main controller  60  causes the transmission controller  68  to transmit information indicating that the measured SpO2 value is unreliable while the NIBP measurement is performed. In addition, the measured SpO2 value may be unreliable until the blood flow stopped by the inflated cuff restores to the normal condition after the deflation of the cuff. Accordingly, in this embodiment, the main controller  60  determines whether the SpO2 value is reliable or not after the NIBP measurement is finished. For example, it is judged whether a prescribed time period is elapsed after the completion of the NIBP measurement. When it is determined that the measured SpO2 value is reliable, the main controller  60  causes the transmission controller  68  to transmit information indicating that the measured SpO2 value is reliable. 
     Thereafter, a timer is activated to count a prescribed measurement interval (e.g., 5 minutes) (step S 50 ). When the prescribed interval is expired, the routine is returned to step S 44 , thereby repeating the control actions to step S 50 . 
     On the other hand, for starting receiving control with the receiver, the power switch is turned on (step S 61 ) as shown in  FIG. 18B . Upon the activation, whether or not the respective data from the transmission controller  68  have been received is determined (step S 62 ). When the transmission data have been received, the respective received data are displayed (step S 63 ). Subsequently, when the transmission data have failed in receiving or after the respective received data have been displayed respectively, whether or not the measurement flag transmitted from the transmission controller  68  has been received is determined (step S 64 ). When the measurement flag has been received, display indicating that blood pressure is being measured is performed, and display of SpO2 value is erased, whereby an alarm about receiving processing of the SpO2 value is cancelled.  FIG. 19  shows a monitor screen of a vital sign data receiver  90  as a display example in the receiver. 
     Meanwhile, the receiver  90  determines whether the information indicating that the measured SpO2 value is unreliable is received from the transmission controller  68 . When it is determined that the information is received, the receiver  90  holds the measured SpO2 value (e.g., 97%) at the moment that the information is received. 
     In addition, an indication that the measured SpO2 value is unreliable due to the NIBP measurement is performed on the display of the receiver  90 . For example, the numerical value which has been displayed is deleted; a symbol “-” or the like is displayed instead of the numerical value which has been displayed; the displayed numerical value is caused to blink or the color of the displayed numerical value is change with a message that the displayed SpO2 value is unreliable. Namely, even if the measured SpO2 value or the measured pulse rate decrease, the receiver  90  judges that such changes are caused by the NIBP measurement, and will not generate an alarm or the like indicating the serious decrease of the SpO2 value. 
     When the receiver  90  receives the information indicating that the measured SpO2 value is reliable, the holding of the measured SpO2 value is canceled and the displayed numerical value is updated by the latest measured SpO2 value. The display of the measured SpO2 value is continued in a real time manner after then. 
     There may be configured such that the holding of the measured SpO2 value is effected when the receiver  90  receives a flag indicating the initiation of the NIBP measurement. 
     Thereafter, whether NIBP measurement data from the transmission controller  68  have been received or not, or whether an error flag has been received during the NIBP measurement is determined (step S 67 ). When the NIBP measurement data have been received, the received blood pressure value is displayed (step S 68 ). When the error flag has been received, display indicating the NIBP measurement fault is performed (step S 69 ). Subsequently, whether or not the completion flag from the transmission controller  68  has been received is determined (step S 70 ). When the completion flag has been received, an SpO2 value is displayed, and an alarm indicating receiving processing of SpO2 value is enabled (step S 71 ). The routine is returned to step S 62 , thereby repeating the control actions to step S 71 . 
     The preferred embodiment of the invention has hitherto been described. However, it should be understood that the invention is not limited thereto, and may variously be modified, altered, and changed within the scope of the invention. For example, the measured parameter may include a concentration of carbon dioxide in gas expired through nostrils, electroencephalogram and electromyogram of the subject. In a case where the concentration of carbon dioxide in gas expired through nostrils is measured, as shown in  FIG. 20 , a carbon dioxide sensor  95  is placed below the nostrils of the patient P and signals indicating the concentration of carbon dioxide are transmitted to the vital sign telemeter  10  via a lead wire  96  connecting the main body  40  and the carbon dioxide sensor  95 .