Abstract:
A portable biological signal measurement/transmission system includes: a body unit; and at least one biological signal processing unit detachably connected to the body unit, and including a signal processor which processes a biological signal, the biological signal processing unit including a first transmitter which transmits the biological signal to the body unit when the biological signal processing unit is connected to the body unit.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a portable biological signal measurement/transmission system which includes at least one of a plurality of sensors for measuring a plurality of biological signals such as ECG, SpO2, and NIBP and which transmits biological signal information measured by the sensor to a monitoring device. 
         [0002]    JP-T-2008-526443 discloses a related-art patient monitoring device which measures biological signals. The related-art patient monitoring device is shown in  FIGS. 13 to 16 . Referring to  FIG. 13 , the patient monitoring device  20  is defined by a housing  24  that receives input from a plurality of sensors, each forming part of physiologic sensor assemblies  28 ,  32  and  36 , in this instance ECG, SpO2 and NIBP (non-invasive blood pressure) assemblies. The housing  24  includes a display  88  for vital sign numerics, waveforms and other patient data, as well as a user interface  92 , shown in  FIG. 14 , that permits operation of the monitoring device  20 . 
         [0003]    Referring to  FIG. 13 , the display  88  is provided on a front facing side of the housing  24 , as well as a plurality of adjacent actable buttons defining the user interface  92 . The display  88  is a quarter (QVGA) color display, and the size of the display  88  is approximately 3.5 inches (measured diagonally). More particularly, the display  88  is an LCD having a pixel count of  240  by  320 . The display  88  preferably includes a backlight (not shown) to improve readability of the display under low ambient light conditions. 
         [0004]    As to the profile of the device  20 , the size of the housing  24  is approximately 5.3 inches in height, 7.5 inches in width, and 2.0 inches in depth. In spite of the lightweight design, however, the monitoring device  20  is extremely durable and rugged in which the device is equipped to handle various loads that may be encountered in a patient-related setting. For example, the housing  24  includes a center or intermediate rubberized bladder  26  disposed between a front housing half and a rear housing half that is disposed peripherally therebetween about the device housing  24  in order to assist in cushioning the monitoring device  20  from impact or shock loads and to retain the interior of the device from dust or other contaminants . To further assist in cushioning the monitoring device  20 , each of the corners of the housing  24  are curved to provide an effective contour. A battery compartment (not shown) is also formed within the housing  24 , the cover of the battery compartment being essentially flush with the rear facing side  61  of the housing such the compartment does not protrude from the overall profile of the monitoring device  20 . The rear facing side  61  of the housing  24  further includes a set of rubberized pads or feet  58 , enabling the monitoring device  20  to be placed on a flat surface, as needed. In addition, each of the buttons included in the user interface  92  is elastomerized to aid in the overall durability and ruggedness of the monitoring device  20 , the buttons being positioned so as not to overly protrude from the facing surface  84  of the housing  24  and allowing the device to maintain a relatively compact profile. 
         [0005]    The compact profile of the device housing  24  enables the monitoring device  20  to be patient wearable. A pair of tabs  132 , shown in  FIG. 13 , provided on opposing lateral sides of the device housing  24  enable the monitoring device  20  to be secured to a patient-wearable harness  135  or alternatively a strap  137  can be attached to the side tabs  132  permitting hand-held and portable operation of the monitoring device  20 . The strap  137  can be used additionally for transport operations along with a transport belt  139  with respect to a gurney  138  or other transport apparatus. Otherwise and as noted above, the monitoring device  20  can be suitably positioned upon a table or other flat surface using the rubberized pads  58  provided on the rear facing side  61  of the device housing  24 . 
         [0006]    In addition to being compact and durable, the monitoring device  20  is extremely lightweight. The entire assemblage shown in  FIG. 13  weighs approximately two pounds. 
         [0007]    As noted above, a plurality of physiologic sensor assemblies are tethered to the housing  24 , including an ECG sensor assembly  28 , an SpO2 sensor assembly  32  and an NIBP sensor assembly  36 , respectively, the sensor assemblies being shown in  FIG. 13  only for the sake of clarity. 
         [0008]    A brief treatment of each tethered physiologic sensor assembly  28 ,  32 ,  36  is now provided for the sake of completeness. More particularly and in brief, the SpO2 sensor assembly  32  is used to noninvasively measure oxygen saturation of arteriolar hemoglobin of a peripheral measurement site of a patient, such as the wrist, a finger, a toe, forehead, earlobe or other area. Reusable or disposable sensor probes can be used. In this instance, a finger clamp  60  is shown in  FIG. 13 , the clamp having a light emitter and a light detector that can be used to detect pulse/heart rate as well as blood oxygen saturation through pulse oximetry. The finger clamp  60  is tethered by means of a cable  64  extending to a pinned connector that mates with a corresponding female connecting port  44 ,  FIG. 15 , that is provided on the exterior of the device housing  24 . 
         [0009]    In brief, the ECG sensor or monitoring assembly  28  includes a lead wire assembly, in which either a three-lead or a five-lead ECG can be utilized. More particularly and by way of example, the herein pictured ECG sensor assembly  28  of  FIG. 13  comprises a set of lead wires  68 , each having electrodes  70  at the ends thereof to permit attachment to the body of a patient, the lead wire assembly including a harness  71  that is attached to a connection cable  72  having a connector which is matingly attachable to the connection port  40  of the device housing  24 . The ECG sensor assembly  28  is further utilized herein with respect to a respiration channel of the monitoring device  20  in order to determine the rate or absence (apnea) of respiration effort through the determination of ac impedance between selected terminals of ECG electrodes  70 , thereby determining the respiration rate of a patient using impedance pneumography based upon movements of the chest wall using a designated reference lead wire. Heart rate is detected for the device  20  using the ECG sensor assembly  28 . 
         [0010]    The ECG sensor assembly  32  creates a waveform (ECG vector) for each lead and further includes a QRS detector that can be adjusted depending upon the patient mode selected. The ECG sensor assembly  28  is further configured to determine heart/pulse rate, if selected, as well as mark pacer spikes in the resulting ECG waveforms byway of a pacer detection circuit. The ECG sensor assembly  28  further includes selectable notch filters of 50 Hz and 100 Hz, 60 Hz and 120 Hz, respectively. 
         [0011]    In brief, the NIBP sensor assembly  36  indirectly measures arterial pressure using an inflatable cuff or sleeve  76 , which is attached to the limb (arm or leg) of a patient (not shown). The remaining end of a connected hose  80  includes an attachment end that can be screwed into a fitted air connector fitting  48  that is provided on the top facing side of the housing  24 . The air connector fitting  48  is connected to a pump (not shown) disposed within the monitoring device housing  24  in order to selectively inflate and deflate the cuff  76  to a specified pressure, depending on the type of patient, using the oscillometric method. Pressure changes are detected by means of circuitry in order to determine systolic, diastolic and mean arterial pressure (MAP). The NIBP sensor assembly  36  is capable of performing manual, automatic and a turbo mode of operation. The assembly  36  can also be equipped, when ECG is also being monitored, with a motion artifact filter if ECG is also being monitored. The filter employs a software algorithm that can be used to automatically synchronize the process of NIBP measurement to the occurrences of the R-wave of the ECG waveform, thereby increasing accuracy in cases of extreme artifact and diminished pulses. An example of a suitable NIBP artifact filter is described in U.S. Pat. No. 6,405,076. Examples of NIBP and ECG sensor assemblies useful for incorporation into the monitoring device  20  are manufactured by Welch Allyn Inc., of Skaneateles Falls, N.Y., among others. With regard to each, the form of sensor assembly can be varied depending on the type of patient, (i.e., adult, pediatric, neonatal) by selective attachment to the connection ports  40 ,  48  that are provided on the monitoring device  20 . Each of the foregoing sensor assemblies further includes electrosurgery interference suppression. As noted, pulse rate can be detected from either the SpO2 or the NIBP channels of the monitoring device  20 . 
         [0012]    It is contemplated, however, that other means for connecting the above noted sensor assemblies  28 ,  32  to the monitoring device  20  other than through the connection ports  40 ,  44 , including wireless means, such as for example, IR, optical, RF, and other nontethered connections could also be employed. It should be further noted that the number of types of physiologic sensor assemblies used with the device  20  can be varied. 
         [0013]    Referring to  FIGS. 13 and 16 , each of the above physiologic sensor assemblies  28 ,  32 ,  36  are internally connected electrically to a CPU  174  that is contained within the housing  24  of the monitoring device  20 . Signal processing for each of the physiologic sensor assemblies  28 ,  32 ,  36  is performed internally through resident processing circuitry, for example, the SpO2 sensor assembly  32  utilizes the Nellcor Puritan MP506 architecture while the NIBP sensor assembly  36  is based upon a design, such as those used in the Micropaq and Propaq vital signs monitors, including, for example, an NIBP Module, Part 007-0090-01, manufactured and sold by Welch Allyn, Inc. Though not shown in  FIG. 16 , the resident circuitry for each of the sensor assemblies  28 ,  32 ,  36  are all integrated into a single logic board in which the ECG and respiration parameters utilize a common processor, such as a Motorola MPC 823 processor of the CPU  174 . Despite being integrated into a single logic board, the remaining physiologic parameters (SpO2 and NIBP) are implemented in a more modular fashion, and utilize their own processors. 
         [0014]    Still referring to the schematic diagram of  FIG. 16 , the contained battery pack  170  is interconnected to the CPU  174 , the latter including a microprocessor, memory, and resident circuitry, in which each are connected to the tethered sensor assemblies  28 ,  32 ,  36  in order to enable processing storage and selective display of the signals provided therefrom as well as perform power conversion between the charging circuit of an optional charging cradle  140  and the contained battery pack, including circuitry to prevent overcharging of the contained battery pack  170  (i.e., 12 volts to 5 volts). The CPU  174  includes available volatile and non-volatile storage for patient data, in the form of Flash memory and SRAM, though other form as are also possible, the CPU  174  being further connected to the display  88 . As noted above, the CPU  174  is presented on a single logic board along with the processors for the physiologic sensor assemblies  28 ,  32 ,  36 . The CPU  174  is intended to handle device-specific aspects, such as alarm limits, display generation, and enabling and disabling of certain features, in which the physiologic sensor assemblies  28 ,  32 ,  36  predominantly only relate data for use by the CPU  174 . It should be noted that portions of the processing function, for example, the ECG processing algorithms, can also reside in CPU  174 , though this can be varied appropriately depending, for example, on the extent of processing power required or packaging concerns. The CPU  174 , predominantly controls the operation of the device  20 , including patient modes, pressures, voltages and the like, as a factory default setting, or either through the user interface  92 , a remote monitoring station  184 , shown in  FIG. 16 , and/or a connected PC  192 , shown in  FIG. 16 . 
         [0015]    In addition to the preceding, the monitoring device  20  as schematically represented in  FIG. 16  further optionally includes a wireless radio card/transceiver  180 , enabling bi-directional wireless communication with at least one remote monitoring station  184 , such as, for example, the Acuity Monitoring Station manufactured and sold by Welch Allyn Inc., using the radio card as inserted in an internal PCMCIA expansion slot (not shown). The radio card  180  is an IEEE802.11 compliant radio card that connects to an antenna  182  that is also disposed within the housing  24  of the monitoring device  20  for transmission over a 2.4 GHz frequency hopping spread spectrum (FHSS) wireless local area network (WLAN) using access points  186 . Additional details relating to an exemplary wireless interconnection, including networking therewith, is described in U.S. Pat. No. 6,544,174. 
         [0016]    As most clearly shown in  FIG. 14 , a lower or bottom facing surface  120  of the device housing  24  includes a latching member  124 , shown in  FIG. 14 , as well as an electrical port  128 , shown in  FIG. 14 , each of which are used in conjunction with an optional charging cradle  140 . As previously noted, the battery pack  170 , only shown schematically in  FIG. 16 , is contained in the rear of the device housing  24  within a rear compartment (not shown). The battery pack  170  provides portable power for the monitoring device  20  in which the battery life is dependent upon certain operational modes of the device. The battery pack  170  is rechargeable by means of charging circuitry contained within the optional charging cradle  140 . The battery pack  170  includes at least one rechargeable lithium-ion battery, such as those manufactured by Sanyo Corporation. In this instance, the battery pack  170  includes two rechargeable batteries. The monitoring device  20  is capable of operation in a stand-alone mode using the contained battery  170  as a power source, the battery having an average runtime of up to approximately 24 hours, depending on the usage of the device. 
         [0017]    In the related-art patient monitoring device disclosed in JP-T-2008-526443, the ECG, SpO2, and NIBP sensor assemblies are individually disposed, the plurality of sensor assemblies are connected to the patient monitoring device through the connector, and all signal processing (for example, signal amplification, AD conversion, and filtering) of biological signal information measured by the ECG, SpO2, and NIBP sensor assemblies are conducted by the CPU in the patient monitoring device. 
         [0018]    Therefore, the related-art patient monitoring device must be provided with a function to process biological signal information measured by the ECG, SpO2, and NIBP sensor assemblies. This limitation causes the following disadvantages; the process burden of the CPU mounted on the patient monitoring device is large, a dedicated device is required for various combinations of parameters, and the patient monitoring device is expensive and bulky so that the patient cannot move around while carrying the patient monitoring device. Furthermore, the measurable parameters are fixed by the design of the patient monitoring device. In the case of a related-art patient monitoring device such as described above, for example, when only ECG monitoring is applied to a non-severe patient, a hospital has to use an over-specified device for this patient which can measure all of the ECG, SpO2, and NIBP parameters. Thereby, it causes a problem in efficiency of apparatus management and operation. 
       SUMMARY 
       [0019]    It is therefore an object of the invention to provide a biological signal measurement/transmission system, which is economical and portable and in which a biological signal processing unit including a signal processing portion that performs processing (for example, signal amplification, AD conversion, and filtering) on measurement data such as ECG, SpO2, and NIBP data, is configured so as to be separable from a body unit, whereby the burden of signal processing in the body unit is reduced so that a small data processing terminal or the like having a high versatility can be employed as the body unit, and further in which a signal processing unit corresponding to a single or plurality of sensor devices can be selectively connected to the body unit depending on the use required by the user, whereby it is possible to realize a less wasteful system which corresponds to the use. 
         [0020]    In order to achieve the object, according to the invention, there is provided a portable biological signal measurement/transmission system comprising: a body unit; and at least one biological signal processing unit detachably connected to the body unit, and including a signal processor which processes a biological signal, the biological signal processing unit including a first transmitter which transmits the biological signal to the body unit when the biological signal processing unit is connected to the body unit. 
         [0021]    The biological signal processing unit may include a connector to which a measuring sensor which measures the biological signal is to be connected. 
         [0022]    The signal processor may perform at least one of a signal amplifying process, a filtering process, and an AD converting process on the biological signal. 
         [0023]    The body unit may include a second transmitter which wirelessly transmits the biological signal, which is received from the biological signal processing unit, to a biological signal remote monitoring device or a patient monitoring device. 
         [0024]    The body unit may include: a battery portion; a storage portion which stores the biological signal, which is received from the biological signal processing unit; an analyzing portion which analyzes the biological signal; a displaying portion which displays the biological signal and the processed data; and an alarm generating portion which generates an alarm related to the biological signal. 
         [0025]    The body unit may be connected to a cradle unit that charges a battery portion of the body unit, and when the body unit is connected to the cradle unit, the biological signal is transmitted to a biological signal remote monitoring device or a patient monitoring device through the cradle unit. 
         [0026]    The cradle unit may include a body temperature probe which performs a spot or continuous measurement of a body temperature. 
         [0027]    The biological signal may include at least one of ECG data, SpO2 data, and NIBP data. 
         [0028]    In order to achieve the object, according to the invention, there is also provided a biological signal processing unit comprising: a signal processor which processes a biological signal; an attaching unit which attaches the biological signal processing unit to a patient; and a nurse call switch, wherein the biological signal processing unit is detachably connected to a body unit. 
         [0029]    The attaching unit may be a clip which is attachable to clothes of the patient. 
         [0030]    The biological signal may include at least one of ECG data, SpO2 data, and NIBP data. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]      FIG. 1  is a block diagram showing the whole configuration of a portable biological signal measurement/transmission system of the invention. 
           [0032]      FIG. 2  is a perspective view showing a body unit and a biological signal processing unit in a first embodiment of the invention. 
           [0033]      FIG. 3  is a view of an example in which an NIBP measuring unit is fixedly connected to a biological signal processing unit. 
           [0034]      FIG. 4  is a view of an example in which a biological signal processing unit is specialized to a measurement of ECG. 
           [0035]      FIG. 5  is a view showing the rear side of the biological signal processing unit. 
           [0036]      FIG. 6  is a perspective view showing a body unit and a biological signal processing unit in a second embodiment of the invention. 
           [0037]      FIG. 7  is a view of an example in which an NIBP measuring unit is fixedly connected to a biological signal processing unit. 
           [0038]      FIG. 8  is a view of a connection cable through which a body unit and a biological signal processing unit are connected to each other. 
           [0039]      FIG. 9  is a view of an example in which a biological signal processing unit is specialized to a measurement of ECG. 
           [0040]      FIG. 10  is a view showing a state where the body unit is connected to a cradle unit. 
           [0041]      FIG. 11  is a view showing the body unit which is fixed to a bed of the patient in the state where the body unit is connected to the cradle unit. 
           [0042]      FIG. 12  is a view showing the body unit which is fixed to an intravenous pole near a bed of the patient in the state where the body unit is connected to the cradle unit. 
           [0043]      FIG. 13  is a front view of a related-art patient monitoring device. 
           [0044]      FIG. 14  is a front perspective view of the related-art patient monitoring device of  FIG. 13 . 
           [0045]      FIG. 15  is a vertical front view of the related-art patient monitoring device of  FIGS. 13 and 14 . 
           [0046]      FIG. 16  is a schematic block diagram of a patient monitoring system including the related-art patient monitoring device of  FIGS. 13 to 15  and a charging cradle. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0047]    The whole configuration of the portable biological signal measurement/transmission system of the invention will be described with reference to  FIG. 1 .  FIG. 1  is a block diagram showing the whole configuration of the portable biological signal measurement/transmission system of the invention. In  FIG. 1 , the reference numeral  1  denotes a body unit which includes a processing unit (CPU)  1   a , a first receiving portion  1   b , a displaying portion  1   c , a second transmitting portion  1   d , a battery  1   e , an alarm generating portion  1   f , a user interface  1   g , a storage portion  1   h , and an arrhythmia analyzing portion  1   i.    
         [0048]    The reference numeral  2  denotes a biological signal processing unit which includes a signal processing portion (CPU)  2   a  and a first transmitting portion  2   b.  The reference numeral  3  denotes a cradle unit which charges the battery of the body unit  1 . The cradle unit  3  includes a power supplying portion  3   a,  a second receiving portion  3   b,  and a third transmitting portion  3   c.  The reference numeral  4  denotes a biological signal measuring sensor which includes an ECG (electrocardiogram) measuring sensor  4   a,  an SpO2 measuring sensor  4   b,  an NIBP measuring sensor  4   c,  and other sensors (not shown). The reference numeral  5  denotes a biological signal remote monitoring device or patient monitoring device which is placed in a nurse&#39;s station or the like. 
         [0049]    Preferably, when connected to the cradle unit  3 , the body unit  1  may transmit a biological signal received from the biological signal processing unit  2 , by means of wired transmission to the biological signal remote monitoring device  5  through the third transmitting portion  3   c  of the cradle unit  3 , and, when not connected to the cradle unit  3 , the body unit  1  may transmit the biological signal by means of wireless transmission to the biological signal remote monitoring device  5  through the second transmitting portion  1   d  in the body unit. 
         [0050]    Furthermore, the body unit  1  can store the biological signal received from the biological signal processing unit  2 , in the storage portion  1   h , and the stored data may be preferably referenced on the displaying portion  1   c . In the case where a transmission failure occurs and the biological signal cannot be transmitted to the biological signal remote monitoring device  5 , particularly, the biological signal is stored in the storage portion  1   h , and hence there is an advantage that data can be prevented from being lost. 
         [0051]    Next, the components of the portable biological signal measurement/transmission system of the invention will be described with reference to  FIGS. 2 to 10 .  FIG. 2  is a perspective view showing in detail the body unit  1  and the biological signal processing unit  2  in a first embodiment of the invention. In  FIG. 2 ,  1  denotes the body unit, and  1   c  denotes the displaying portion which uses a color LED, and which is preferably configured as a touch panel. The reference numeral  1   f  in the upper side denotes an alarm indicator which is configured by an LCD, and which emits color light that is different depending on the kind of the alarm, and  1   f  in the lower side denotes an alarm speaker which notifies a sound alarm that is different depending on the kind of the alarm. The reference numeral  1   j  denotes a record key, and  1   k  denotes an alarm cancel key. 
         [0052]    In  FIG. 2 ,  2  denotes the biological signal processing unit,  2   f  denotes a nurse call key (nurse call switch),  2   c  denotes a connector for connection with the ECG measuring sensor,  2   d  denotes a connector for connection with the SpO2 measuring sensor, and  2   g  denotes a connection cable for connection with the body unit. In the biological signal processing unit  2  in the figure, the measurement objects are the ECG and the SpO2. 
         [0053]    Next, a modification of the biological signal processing unit  2  of  FIG. 2  will be described with reference to  FIG. 3 . The biological signal processing unit  2  of  FIG. 3  shows an example in which the NIBP measuring unit  4   c  is already fixedly connected to the biological signal processing unit  2 , and, in addition to a measurement of NIBP, measurements of ECG and SpO2 can be selected as required. 
         [0054]    Next, another modification of the biological signal processing unit  2  of  FIG. 2  will be described with reference to  FIG. 4 . The biological signal processing unit  2  of  FIG. 4  is specialized to the measurement of ECG, and used in the case where only the measurement of ECG is required. Although  FIG. 4  shows the case where the biological signal processing unit  2  can be used only in the measurement of ECG, it is obvious that the biological signal processing unit  2  may be specialized to another measurement object or the measurement of SpO2 or NIBP. 
         [0055]    Next, a configuration example of the biological signal processing unit  2  of  FIG. 2  will be described with reference to  FIG. 5 .  FIG. 5  shows the rear side of the biological signal processing unit  2 . The configuration of the rear side is common to the biological signal processing units  2  of  FIGS. 2 to 4 . As shown in the figure, a clip  2   h  which functions as an attaching unit for attaching the biological signal processing unit  2  to clothes or the like of the patient is disposed in the rear side of the biological signal processing unit  2 . As the attaching unit, any unit other than a clip may be used as far as the unit can fix the biological signal processing unit  2  to clothes or the like of the patient. 
         [0056]    In a related-art patient monitoring device, a cable which extends from a sensor assembly is connected directly to a body unit. When the sensor assembly is to be attached to the patient, therefore, it is difficult to lay the cable, and the difficulty may cause the so-called spaghetti syndrome. In the invention, by contrast, a cable which extends from a sensor assembly is not connected directly to the body unit  1 , but once connected to the biological signal processing unit  2  which can be placed in the vicinity of the body of the patient. Therefore, the cable can be shortened, and, when the sensor assembly is to be attached to the patient, the cable can be easily laid. Moreover, the clip  2   h  is disposed in the biological signal processing unit  2 , and cables and the like can be housed in the vicinity of the body of the patient. Therefore, it can be said that cable laying is further facilitated. 
         [0057]    In the invention, the functions, which, in a related-art patient monitoring device, are concentrated into a so-called monitoring device, are dispersed between the body unit  1  and the biological signal processing unit  2 , and hence the body unit  1  can be miniaturized and lightened. When the patient is to move, therefore, the body unit can be easily carried. Moreover, a larger battery can be mounted, and long term monitoring is enabled. 
         [0058]      FIG. 6  is a perspective view showing in detail a body unit and a biological signal processing unit in a second embodiment of the invention. In  FIG. 6 ,  1  denotes the body unit, and  1   c  denotes a displaying portion which uses a color LED, and which is preferably configured as a touch panel. The reference numeral  1   f  in the upper side denotes an alarm indicator which is configured by an LCD, and which emits color light that is different depending on the kind of the alarm, and  1   f  in the lower side denotes an alarm speaker which notifies a sound alarm that is different depending on the kind of the alarm. The reference numeral  1   j  denotes a record key, and  1   k  denotes an alarm cancel key. 
         [0059]    In  FIG. 6 ,  2  denotes the biological signal processing unit,  2   f  denotes a nurse call key (nurse call switch),  2   c  denotes a connector for connection with the ECG measuring sensor,  2   d  denotes a connector for connection with the SpO2 measuring sensor, and  2   g  denotes a connection cable for connection with the body unit  1 . In the biological signal processing unit  2  in the figure, the measurement objects are the ECG and the SpO2. The biological signal processing unit  2  of  FIG. 6  is different from that of  FIG. 2  in that the connection cable  2   g  for connection with the body unit  1  is configured so as to be separable also from the biological signal processing unit  2 . When this configuration is employed, the biological signal processing unit  2  can be used while its kind is selected depending on the patient. Therefore, wasteful functionality can be reduced. 
         [0060]    Next, a modification of the biological signal processing unit  2  of  FIG. 3  will be described with reference to  FIG. 7 . The biological signal processing unit  2  of  FIG. 7  shows an example in which the NIBP measuring unit  4   c  is already fixedly connected to the biological signal processing unit  2 , and, in addition to a measurement of NIBP, measurements of ECG and SpO2 can be selected as required. The biological signal processing unit  2  of  FIG. 7  is different from that of  FIG. 3  in that the connection cable  2   g  for connection with the body unit is configured so as to be separable also from the biological signal processing unit  2 . When this configuration is employed, the biological signal processing unit  2  can be used while its kind is selected depending on the patient. Therefore, wasteful functionality can be reduced. 
         [0061]    Next, the connection cable  2   g  which is used in the biological signal processing units  2  of  FIGS. 6 and 7  will be described with reference to  FIG. 8 . The connection cable of  FIG. 8  connects between the body unit  1  and the the biological signal processing unit  2 , and can be applied to any kind of biological signal processing unit. 
         [0062]    Next, a modification of the biological signal processing unit  2  of  FIG. 4  will be described with reference to  FIG. 9 . The biological signal processing unit  2  of  FIG. 9  is specialized to the measurement of ECG, and used in the case where only the measurement of ECG is required. The biological signal processing unit  2  of  FIG. 9  is different from that of  FIG. 4  in that the connection cable  2   g  for connection with the body unit  1  is configured so as to be separable also from the biological signal processing unit  2 . When this configuration is employed, the biological signal processing unit  2  can be used while its kind is selected depending on the patient. Therefore, wasteful functionality can be reduced. Although  FIG. 9  shows the case where the biological signal processing unit  2  is specialized to the measurement of ECG, it is obvious that the biological signal processing unit  2  may be specialized to the measurement of SpO2 or NIBP. The measurement objects of the biological signal processing unit  2  are not limited to ECG, SpO2, and NIBP, and the biological signal processing unit  2  may be configured so as to be expandable to measure other measurement objects such as Temp (body temperature) and CO2 (concentration of expiratory carbon dioxide). 
         [0063]      FIG. 10  is a view showing a state where the body unit  1  is connected to the cradle unit  3 . The cradle unit  3  is fixed to an intravenous pole  6 . In this state, the battery  1   e  of the body unit  1  is charged by the power supplying portion  3   a  of the cradle unit  3 . Measurement data are transmitted from the second transmitting portion  1   d  of the body unit  1  to the biological signal remote monitoring device  5  through the second receiving portion  3   b  and third transmitting portion  3   c  of the cradle unit  3 . 
         [0064]      FIGS. 11 and 12  show examples in which the body unit  1  is fixed in the state where the body unit  1  is connected to the cradle unit  3 . In  FIG. 11 , the body unit  1  is fixed to a part of the head side of a bed of the patient by a fixing device  6   a , and, in  FIG. 12 , the body unit  1  is fixed to an intravenous pole  6  for the patient by a mounting device  6   b.  Preferably, the cradle unit  3  has a structure which enables the structure to be disposed in the vicinity of the patient. Alternatively, the cradle unit  3  may have a structure which includes a body temperature measuring probe that allows a nurse to perform a spot or continuous measurement of the body temperature on the patient. Data which are related to the body temperature, and which are measure by the probe may be displayed on the displaying portion  1   c , and, transmitted to the biological signal remote monitoring device or the patient monitoring device  5  through the cradle unit  3 . 
         [0065]    As in the biological signal processing unit  2  shown in  FIGS. 2 to 4  (or  FIGS. 6 to 8 ), the system of the invention is configured by one of the group of a plurality of kinds of biological signal units, and the body unit  1 , or the invention is a so-called combination invention. The configuration which is common to all the embodiments, and which is important is that the group of biological signal units has a common interface, and each of the biological signal units  2  are attachable and detachable to and from the body unit  1 . According to the configuration, simply by replacing the biological signal processing unit  2  with another one, the user can select the parameter to be measured. Although, in the embodiments, the connection example in which the biological signal processing unit  2  is connected with the wire to the body unit  1  has been described, the invention is not limited to wired-connection. 
         [0066]    As described above, unlike the related art, it is not required to respectively prepare patient monitoring devices for parameters to be measured. It is simply necessary that the common body unit is prepared, and an adequate one of the biological signal processing units is connected to the body unit depending on the use. Therefore, not only the cost, but also the expandability, the maintainability, and the efficiency of the apparatus management can be remarkably improved. 
         [0067]    According to an aspect of the invention, the biological signal processing unit which processes measurement data such as ECG, SpO2, and NIBP data, and which corresponds to a single or plurality of sensor devices is separable from the body unit constituting the portable biological signal measurement/transmission system. Therefore, the user can select a measuring sensor in accordance with the necessity in measurement of a biological signal of the patient. Consequently, the cost can be reduced, the maintainability can be improved, and the efficiency of the apparatus management can be enhanced. 
         [0068]    Since a part of functionality of a related-art patient monitoring device is separated to the biological signal processing unit, furthermore, a small data processing terminal or the like having a high versatility can be used as the body unit, so that the cost of the body unit can be reduced and the patient can move around while carrying the body unit.