JP5396636B2 - Wireless biological information sensing system - Google Patents

Description

  The present invention controls a large number of portable measuring instruments with a central unit via wireless communication, and without changing the hardware, the number of measuring units is maintained while maintaining the simultaneity among a plurality of measuring units. Alternatively, the present invention relates to a wireless biological information sensing system that can easily change the number of objects to be measured using it in a scalable manner.

  Portable measuring instruments that record biological information of waveforms such as body temperature, blood flow, heart sounds or electrocardiograms in real time are already well known. In such a portable measuring instrument, (1) a series of measured data is stored in the portable measuring instrument, and sent to a management device via a wired or wireless link in response to an output request from the outside, (2) One or a small number of measured data is temporarily stored in a portable measuring instrument, and each small number of data is sequentially transmitted to a management apparatus through a wireless link.

As disclosure corresponding to the above (2), for example, there are Patent Documents 1 to 3.
As shown in FIG. 14, the wireless electroencephalogram measurement system described in Patent Document 1 (Japanese Patent Publication No. 2003-533262) mainly includes a serial data communication helmet and a synthesis unit. The helmet consists of an electrode, an antenna, a data bus, a power cable, an input / output circuit (I / O) connected to the individual electrodes, and a power cable. The electrode is composed of a scalp contact portion and a signal amplifier, and an analog electric signal is output from the potential at the contact portion by a high input impedance amplifier. The amplifier is an operational amplifier capable of removing common-mode noise, and can remove electromagnetic noise floating in the measurement environment widely, such as power supply noise. These analog signals are connected to the synthesis unit for each electrode, subjected to waveform analysis processing by a digital signal processing circuit (DSP) through an analog-digital converter, and then diagnosed. The diagnosed result can be stored in the memory in the synthesis unit, and information can be exchanged with the host computer via the antenna attached to the serial communication helmet by the transmission / reception unit.

  Multi-channel analog signals are processed by the DSP by time division multiplexing. Multiplexers for time-sharing can be placed in the serial communication helmet, but those that are not integrated in the DSP become unstable due to control signal skew, etc., so they are placed on the DSP side. Yes.

  In the measurement of biological information such as brain waves disclosed in Patent Document 1, it is desirable to optimize the number of channels and the band according to the measurement purpose. However, this requires updating the processing circuit each time the number of channels is changed. This is because information on a plurality of electrodes is aggregated for each subject, data is digitized by a synthesis unit attached to the subject, and processing such as meaning is performed. Furthermore, as the number of channels increases, it is necessary to dramatically increase the size of the multiplexer and the processing speed of the DSP. As a result, additional devices such as a large-capacity battery pack and a fan for cooling a high-speed DSP are required. It was necessary. From another viewpoint, this means that there is an upper limit to the equipment that can be worn by the subject under a realistic measurement environment, and the scale of the number of measuring instruments to be used is limited.

  In addition, in the wireless biometric information sensor described in Patent Document 2 (Japanese Patent Laid-Open No. 2005-160983), transmission means for digitizing the sensor output and temporarily storing it or wirelessly transmitting it to another device is provided. It has a function (transmission / reception module) for receiving and transferring digitized sensor information from other sensor units.

  Note that the wireless biological information sensor shown in Document 2 is characterized by autonomous operation. For this reason, the expandability problem of the wireless electroencephalogram measurement system disclosed in Patent Document 1 is solved. However, it does not have a synchronous control function for sensing in accordance with an external control signal. For this reason, it is impossible to measure using a plurality of sensor units and obtain the correlation between the measured values, or to drive them synchronously and measure them completely simultaneously.

  Patent Document 3 (US Pat. No. 6,441,747) discloses a programmable wireless system for medical monitoring. It comprises a base unit and a plurality of wireless sensor programmable transceivers, each wirelessly programmable. This base unit controls the transceiver by performing registration, arrangement, data collection, transmission command issuance and the like using wireless technology. The biological information from the wireless transceiver is demodulated and supplied to the display monitor through a standard interface.

  In the wireless system disclosed in Patent Document 3, when a global time signal is transmitted from the base unit, each biosensor transmitter / receiver transfers the signals simultaneously acquired to the base unit. It is. Data collection is started when a collection command is transmitted from the base unit to the sensor. In addition, transmission of the collected data starts with a command from the base unit. Further, in order to utilize a plurality of sensors in a single frequency channel, time division multiplexing is performed, and the above wide-area time signal is used as a time reference in the wireless system.

  The present invention is the same as Patent Document 3 described above in that the measurement system includes an overall unit and a plurality of measurement units. However, the following points are clearly different. In other words, in the present invention, the central unit distributes a time reference, receives transmission signals from a plurality of measurement units, demodulates a biological signal, and stores, transmits, or displays the biological signal. Each measurement unit includes a sensor unit and a transmission / reception unit, receives the time reference, performs biological signal measurement according to the output of a signal generator that can be phase-synchronized with the distributed time reference, and Measurement data is transmitted wirelessly.

Special table 2003-533262 gazette JP 2005-160983 A US Pat. No. 6,441,747

  In the measurement system that records biological information of multiple freely moving specimens simultaneously in real time, the portable measuring instrument attached to the specimen as described above and the base that receives and integrates the measurement data from each portable measuring instrument It is desirable to connect the stations with wireless communication. Generally, in wireless communication, light or radio waves are used, but in the case of light, communication cannot be performed if the communication path is blocked by something, but in the case of radio waves, such a measurement system is rarely blocked. In many cases, wireless wireless communication is used.

  However, when transmitting radio waves indoors, for example, problems such as interfering radio waves from other electrical devices such as digital devices, and multipath fading due to reflections from reflectors such as indoor desks, lighting fixtures, and walls It is well known that occurs. When such a problem cannot be ignored, for example, in the invention described in Patent Document 3, communication between the base unit and the biosensor transceiver is interrupted, transmission of various commands and measurement data is interrupted, and data is lost. It can be easily predicted that this will occur.

  For this reason, it is a measurement system that can record biological information of a plurality of subjects that move freely in real time at the same time, and is a measurement system that uses wireless communication by radio waves, but it is difficult to cause data loss when operating indoors Is required.

  The present invention generally comprises a plurality of autonomously operating measurement units and a single or a plurality of central management devices (overall units) that include a transmission / reception unit and acquire sensor information by wireless communication with these measurement units. For example, in the measurement by monopolar induction, the measurement unit measures the potential of the scalp with reference to a common ground line. In this measurement unit, the measured potential value is converted into digital information via an analog-to-digital converter (ADC) via a high-impedance amplifier (usually an instrumentation amplifier) that prevents common-mode noise superposition, and then the measurement potential is measured. Data is processed by a micro processor (MPU) installed in the unit. The said measurement unit receives the signal used as a time reference via the provided radio | wireless transmission / reception part, and measures a biological signal according to this time reference. This data processing is processing for digitizing the measured value and transmitting it to the overall unit. In this transmission, frequency division multiplexing (FDM) or code division multiplexing (CDM) is used so as not to interfere with each other even when transmitting simultaneously.

  More specifically, the present invention is a wireless biological information sensing system that includes a central unit that distributes a time reference and a plurality of measurement units that receive the time reference. The overall unit receives transmission signals from the plurality of measurement units, demodulates the biological signals, and stores, transmits, or displays them. The measurement unit includes a sensor unit and a transmission / reception unit, performs biological signal measurement according to an output of a signal generator that can be phase-synchronized with a distributed time reference, and wirelessly transmits measurement data to the overall unit. is there. The measurement unit performs measurement simultaneously. That is, there is a period in which the sensor units of at least two measurement units are simultaneously in the measurement process.

  The time reference signal may be a signal generated from a periodic signal generated by a crystal oscillator. This crystal oscillator can be calibrated by an atomic clock that generates a standard time. Alternatively, a crystal oscillator synchronized with an atomic clock may be used. This atomic clock is, for example, the Cs133 microwave absorption line 9,192,631,770 Hz based on the definition of the second of the SI unit system established in 1967 (the resolution of the 1967 13th International Metrology Meeting). Used to generate a reference signal by drawing the vibration of the crystal oscillator into this. By using the crystal oscillator calibrated by the atomic clock in this way, accurate time management can be performed without compensating the accuracy of the individual clock for each apparatus.

  The wireless transmission is an electromagnetic wave transmission, and the reference signal can be transmitted by being superimposed on the electromagnetic wave. As electromagnetic waves, radio waves or light can be used, and signals can be superimposed by modulating them.

  The supervising unit stores a data processing unit for grouping measurement data received at intervals determined by the reference signal, and a measurement data grouped above with a time stamp based on the reference signal. And a storage unit.

  The overall unit may have an electrically rewritable table in which information for identifying each of the measurement units is described, and a filing system that groups the data of the measurement units according to the information.

  The measurement unit can be realized by using a phase locked loop circuit that synchronizes the internal time reference of the measurement unit with the distributed time reference.

  The phase-locked loop circuit may be provided with a voltage maintaining circuit that maintains an oscillation frequency immediately before being interrupted when the reference signal is interrupted, thereby providing a signal that meets the time reference. Can do.

  Each of the measurement units includes analog-digital (AD) conversion means for converting the detected analog biological signal into digital data for each period determined by the internal time reference in the sensor unit.

  Each of the analog-to-digital conversion means of the plurality of measurement units converts an analog biological signal into digital data within a time thread obtained by subdividing the cycle. Thus, measurement and AD conversion are completed within the above cycle.

  Each of the measurement units includes analog-to-digital conversion means for converting an analog biological signal detected at the same time into digital data for each period determined by the internal time reference in the sensor unit. In this method, simultaneous measurement is performed by a plurality of measurement units.

  In addition, by using the above multiple measurement units for multiple test objects, even when using a single integrated unit, different test items or subjects can be measured together, greatly simplifying the system Can be

  One or a plurality of measurement units can be attached to a plurality of inspection objects, respectively, and a time reference can be distributed to these measurement units from one integrated unit. Moreover, the measurement data from these measurement units can be received by the control unit.

  Furthermore, a wireless biological information sensing system comprising a stimulus generating means that operates in accordance with the time reference signal, wherein the stimulus from the stimulus generating means is given to the test object and the biological signal caused by the stimulus is measured It is. With this system, for example, the influence of some video on the subject can be converted into data using differences in biological signals.

  In order to give the stimulus from the stimulus generating means to the inspection object as described above, the stimulus generating means includes means for providing the measurement unit with a predetermined stimulus start time signal related to the start time of the stimulus. . This may be any signal transmission means. For example, signal transmission means such as light, radio waves, magnetic waves, and sound. Moreover, in order to receive such a signal, the said measurement unit is provided with the input means which inputs the said stimulus start time signal. For example, a photodiode, an antenna, a coil, a microphone, etc. and their signal processing means. The stimulation start time data input from this input means is transmitted to the overall unit together with the measurement data. The stimulus start time signal may be synchronized with the above stimulus or may be notified in advance.

  In order to simplify the apparatus, the stimulation start time signal may be provided to the measurement unit by the same presentation means as the stimulation presented to the subject by the stimulation generation means. For example, when a stimulus is given by a moving image, a signal based on a change in screen illuminance that is not noticed by the subject is presented 3 seconds before the stimulus. In addition, when a stimulus is given by sound, for example, the signal is presented as a non-audible sound immediately before the stimulus sound.

  For example, when measuring the responses of multiple subjects to a single event simultaneously as biological information of waveforms such as electroencephalograms, electromyograms, and electrocardiograms, even if subjects move around and are exposed to noise and fading, data It is possible to realize a measurement system in which it is difficult for omission to occur.

It is a block diagram which shows the wireless biometric information sensing system of this invention. A plurality of measurement units and a control unit, wherein the control unit transmits a time reference to the plurality of measurement units, receives and demodulates a signal transmitted from the measurement unit, and stores, transmits, or displays the time reference; To do. The measurement unit includes a sensor unit and a transmission / reception unit, performs biological signal measurement at a timing based on the distributed time reference, and wirelessly transmits measurement data to the overall unit. It is the block diagram of the (a) control unit of the wireless biological information sensing system of this invention, and the block diagram of the (b) measurement unit. The overall unit modulates the radio frequency carrier wave signal from the local oscillator with the signal from the time reference generator, and transmits it as a time reference signal radio wave from the antenna. The radio wave is received by the measurement unit and the time reference signal is demodulated. Other blocks are controlled using this time reference signal. The signal detected by the sensor electrode is converted from analog to digital, and the carrier wave is modulated by the generated digital signal and transmitted. The radio signal transmitted from the measurement unit is received by the overall unit, detected, decoded as necessary, and then displayed, stored, or transmitted through data processing. The example of a measurement unit provided with a transmission / reception antenna is shown. A radio signal received by the receiving antenna is branched into a synchronous oscillation circuit and a detection circuit. In the detection circuit, a clock component and a frequency slot component specific to each measurement unit are separated. A desired frequency band is selected from signals transmitted by frequency division multiplexing by using a filter capable of changing the filtering frequency in a programmable manner in the identification circuit. A synchronous oscillation (PLL) circuit generates a transmission signal synchronized with a carrier wave of a reception signal. (B) shows a measurement unit, and (a) shows an example in which a set of reference electrodes used in common with four sets of exploration electrodes connected thereto is mounted on the head. The probe electrode can be attached to any part of the head, but it is usually attached to the site defined by the international standard for electroencephalogram measurement. In addition, the four reference units are concentrated in the earlobe. An example of a receiving unit that is used as a part of the overall unit and in which measurement data is transmitted by the wavelength multiplexing method is shown. The received radio wave is detected by a detection circuit equipped with a programmable bandpass filter (PBPF), and a signal of a target measurement unit is selected. This PBPF can be changed in a programmable manner by a signal from the MPU. An example of a general unit configured by integrating a plurality of receiving units and a time reference unit that transmits a time reference signal through a USB bus is shown. It is a figure which shows the frequency management table | surface in the case of using the integrated unit of the structure shown in FIG. A plurality of receiving units are arranged in different frequency bands, and a plurality of measuring units are associated with each receiving unit. A dedicated frequency band is used for time reference. An example of embedding a time reference signal displayed on the time axis is shown. When a digital signal is transmitted from the central control unit to each unit, a synchronization word pattern is inserted and this period is used as a time reference. When individually controlling each measurement unit using the same frequency band, it is individually controlled by code division multiplexing. It is a block diagram which shows the example of the receiving unit used for the supervision unit shown in FIG. The received radio wave is detected by a detection circuit equipped with a programmable bandpass filter (PBPF), and the signal of the target measurement unit is selected. Radio waves modulated with digital signals are demodulated by synchronous detection. It is a schematic diagram which shows the wireless biometric information sensing system in the case of measuring biometric information by grouping a plurality of measurement units and attaching them to different subjects. In this system, the supervising unit registers the measurement unit, the subject to be worn, and the wearing place after wearing. It is a schematic diagram which shows the Example which uses a some measurement unit for a different object with respect to one control unit. It is a schematic diagram which shows the wireless biometric information sensing system using the audiovisual information control apparatus which controls the content by which the marker of a stimulus start was embedded. This audio-visual information control apparatus sets presentation conditions such as timing when a single intense stimulus or repeated minute stimulus of video or audio is presented to a subject or test animal. In addition, an audiovisual information display device that displays contents to a subject by visual, auditory, or both methods is used. Further, a stimulus marker detector that is installed in the vicinity of the audiovisual information display device and detects a stimulus point from display information is used. Information at the time of stimulation presented on the display device is detected. It is a figure which shows the example of the electroencephalogram acquired with the wireless biometric information sensing system of FIG. 1 is a block diagram showing a wireless electroencephalogram measurement system described in Patent Document 1. FIG.

  Embodiments of the present invention will be described below in detail with reference to the drawings. In the following description, devices having the same function or similar functions are denoted by the same reference numerals unless there is a special reason.

  As shown in FIG. 1, the present invention includes a plurality of autonomously operating measurement units 200 and a central unit that includes a transmission / reception unit and acquires sensor information by wireless communication with a plurality of these measurement units and functions as a central management device. 100. The overall unit 100 transmits time references to the plurality of measurement units 200 and receives and demodulates signals transmitted from the measurement units to store, transmit, or display them. The measurement unit includes a sensor unit and a transmission / reception unit, performs biological signal measurement at a timing according to the output of a signal generator that can be phase-synchronized with a distributed time reference, and wirelessly transmits measurement data to the central unit. To be sent. In the present invention, the sensor units of a plurality of measurement units are simultaneously operated to perform measurement at the same time.

  In order to realize this, the overall unit 100 modulates a radio wave carrier signal from the local oscillator 102 with a signal from the time reference generator 101 as schematically shown in FIG. The antenna 109 transmits the signal as a time reference signal radio wave. The modulator 103 can use any modulation method such as analog modulation or digital modulation. The circulator 108 is for sharing one antenna for reception and transmission.

  In the measurement unit 200 that has received the time reference signal radio wave, the time reference signal is demodulated from the time reference signal radio wave as shown in FIG. The demodulated time reference signal is converted into a frequency used when other blocks are controlled.

  The measurement unit 200 that has received the time reference signal radio wave amplifies the signal detected by the sensor electrode, performs signal processing as necessary to remove unnecessary components, and then performs an analog-digital (AD) converter 206. The carrier wave from the oscillator 210 is modulated with the generated digital signal and transmitted by the antenna 209.

  The radio wave transmitted from the measurement unit 200 is received by the overall unit 100, detected, decoded as necessary, and then displayed, stored, or transmitted through data processing.

  In order to obtain a higher-performance measuring unit, for example, the configuration shown in FIG. 3 may be used.

  First, the radio signal received by the receiving antenna is branched to the time reference signal demodulator 201 and the detection circuit 221. In the detection circuit 221, a clock component and a frequency slot component specific to each measurement unit (hereinafter, a specific component of the measurement unit) are separated. The identification circuit 222 for extracting the specific component of the measurement unit can select a desired frequency band from a signal transmitted by frequency division multiplexing by using a filter that can change the filtering frequency in a programmable manner. If the message is addressed to the measurement unit, the message is transmitted to the control unit 250 through the input / output (IO) circuit 223 and the internal bus 220. The control unit 250 is a computer including an arithmetic unit (MPU) 250 and a memory 251 and operates according to a clock signal from a system clock 252 of 10 MHz, for example.

  The time reference signal demodulator 201 is a synchronous oscillation (PLL) circuit, for example, and generates a transmission signal synchronized with the carrier wave of the reception signal. This is an output of an oscillation signal from a voltage controlled oscillator (VCO) 229, which is a local oscillator of the PLL circuit, to the identification circuit. The VCO used here is preferably a crystal oscillator composed of a high-Q oscillator circuit, a crystal oscillator calibrated by an atomic clock, or a crystal oscillator that refers to an atomic clock. In this VCO, the oscillation frequency can be set at an arbitrary position in a certain frequency band by the control voltage. The time reference signal demodulator 201 mixes the signal from the voltage-controlled oscillator (VCO) 229 and the received radio wave with a mixer (Mixer) 227, converts the frequency to a low frequency side, and converts it to a low frequency filter ( (LPF) 228 provides a frequency-dependent amplitude. The output of the low frequency filter (LPF) 228 is converted into a DC voltage by the amplifier / rectifier 230, and using this DC voltage, the frequency of the VCO 229 coincides with the carrier wave of the received radio wave or is determined in advance. The DC voltage is controlled for each measurement unit so that there is a difference. Here, by adding the output of the voltage generator 231 to the amplifier / rectifier 230, it is possible to synchronize the oscillation with respect to radio waves of different frequencies. Further, by maintaining the output of the voltage generator 231, the oscillation frequency can be maintained even when the radio wave is interrupted.

  In the initial state, even when there is a frequency difference between the oscillation frequency corresponding to the set voltage Vo and the received signal, the difference is compensated by the PLL circuit. As a result, the VCO automatically synchronizes with the carrier of the received signal and locks in phase with frequency. Once in the synchronized state, it is possible to change the VCO reference voltage V1 while maintaining this locked state.

  Further, the time reference signal demodulator 201 may be a phase locked loop (PLL) circuit configured by using a phase comparator, a loop filter, a voltage controlled oscillator, a frequency divider, and the like and used in a digital circuit.

  By using the signal from the VCO as a local time reference signal, the sampling timing can be determined strictly. At this time, when the sampling rate is lower than the time reference signal, the reference signal can be divided or a desired sampling-like timing signal can be generated by a PLL circuit using a frequency divider.

  The output of the amplifier / rectifier 230 is a demodulated signal of a modulated radio wave, and the output of the low frequency filter (LPF) 233 is an output of direct detection. The direct detection output is converted into a digital signal by the AD converter 234 and transmitted to the control unit 250 through the IO circuit 223 and the internal bus 220. In addition, this information is stored in the memory 251. When radio wave reception is interrupted, the stored information is transferred to the voltage generation circuit 231 through the internal bus 220 and the IO circuit 223. The voltage required to maintain the oscillation frequency is generated.

  The detection signal 260a is used for the detection of the biological signal, but the common-mode noise can be canceled by further taking the difference between them by the operational amplifier 237 using the reference electrode 260b. The output of the operational amplifier 237 is converted into a digital signal by the AD converter 236. At that time, the output of the VCO 229 is frequency-divided by the frequency divider 232 and used as a clock for the AD converter 236, or a timing signal at which the AD converter 236 outputs a digital signal. A digital signal output from the AD converter 236 is transmitted to the control unit 250 through the IO circuit 223 and the internal bus 220.

  The measurement data is temporarily stored in the memory as described above, but is transmitted in response to an instruction from the overall unit or from the control unit 250.

  FIG. 4 shows an example in which a set of reference electrodes used in common with four sets of measurement units and exploration electrodes connected thereto is mounted on the head. The probe electrode can be attached to any part of the head, but is usually attached to a site defined by an international standard for electroencephalogram measurement. The reference electrode is concentrated in the earlobe with all four units.

  The upper measurement unit shown in FIG. 4 is an autonomous unit. For example, in measurement by monopolar induction, the potential of the scalp is periodically measured with reference to a common ground line. In this measurement unit, the measured potential is converted into digital information via an analog-to-digital converter (ADC) via a high-impedance amplifier (usually an instrumentation amplifier) that prevents in-phase noise superposition. This digital information is processed by an ultra-compact processor (MPU) with electrodes. In this process, first, a timing signal and a synchronization signal from the overall unit are received and detected via a wireless transmission / reception unit provided in the measurement unit. Next, the sensor information digitized for each timing signal is transmitted to the host via the transmission / reception unit. The measurement data may be temporarily stored in a buffer such as a FIFO in order to minimize the time delay until the data is transmitted after the timing signal is detected. The ADC is triggered by an internal clock, which is sufficiently larger than the frequency of the external timing signal, and can always provide the latest information in real time according to the external timing trigger. Such an autonomous measurement unit and the control unit are linked wirelessly by frequency division multiplexing or code division multiplexing.

  FIG. 5A shows an example of a receiving portion (receiving unit) of the overall unit that receives a signal from the measurement unit. In the receiving unit shown in FIG. 5A, a high-speed arithmetic processing unit (CPU) is driven by a master clock, whereby all data and signal flows are time-controlled via a bus. (1) First, sampling timing is determined with reference to a clock, and timing signals corresponding to the timing are wirelessly distributed to each measurement unit simultaneously via the transmission / reception unit. (2) The measurement unit receives this timing signal and immediately transmits the sensor information to the overall unit. (3) In the overall unit that receives this, since these signals are frequency division multiplexed or code division multiplexed, parallel collective reception detection is performed. Data of each measurement unit separated by the demultiplexing unit (DEMUX) is buffered in a temporary memory such as a dual port memory (DPM). (4) As shown in FIG. 5B, the CPU accumulates the data accumulated in the DPM based on sensor channel information registered in advance. Further, data is accumulated by giving time information corresponding to the timing signal issued first. By doing in this way, the data of all the measurement units sampled at once can be collected and accumulated orderly.

  6 to 8 show examples applied to a case where a plurality of receiving units are used for one overall unit and measurement data is transmitted by the wavelength multiplexing method. FIG. 6 shows an example of a general unit in which a plurality of receiving units and one time reference unit that transmits a time reference signal are integrated by a USB bus. In the case of USB (Universal Serial Bus), it can be freely removed and attached. Therefore, if the frequency slot used for transmission / reception by each measurement unit and reception unit is managed by a computer (PC), the measurement unit and reception unit are set. Can be set flexibly.

  FIG. 7 shows a frequency management table in the case where the overall unit having the configuration shown in the block diagram of FIG. 6 is used. In this case, each receiving unit is arranged in a different frequency band, and a plurality of measurement units are associated with each receiving unit. The time reference has a dedicated frequency band.

  An example of embedding the time reference signal in this case is shown on the time axis of FIG. In this example, the word pattern and the time reference signal are interleaved. Further, when a digital signal is transmitted from the overall unit to each measurement unit, a synchronization word pattern can be inserted and this period can be used as a time reference. When individually controlling multiple measurement units that belong to the same frequency band (for example, when setting frequency slots individually), multiplex and transmit by code division multiplexing, select the target unit for demodulation, and individually It is possible to control.

  FIG. 9 shows an example of the receiving unit. The received radio wave is detected by a detection circuit 121 equipped with a programmable bandpass filter (PBPF), and a signal of a target measurement unit is selected. This PBPF can be changed in a programmable manner by a signal from the MPU. When the received radio wave is a PSK (Phase Shift Keying) modulated wave, ASK (Amplitude Shift Keying) modulated wave, or multilevel ASK modulation, the carrier wave component is extracted from the received radio wave by a PLL circuit in order to demodulate by synchronous detection. Then, the data can be demodulated by detecting the phase difference and the intensity by the identification circuit 122. The PLL circuit mixes the outputs of the detection circuit 121 and the VCO 129 with a mixer 127, extracts a component close to direct current with the low-frequency filter 128, and generates a voltage at the output of the low-frequency filter 128. The voltage from the circuit 131 is applied by the operational amplifier 130, the output is applied to the VCO 129, and the local oscillation signal generated by the VCO 129 is input to the mixer 127. The output of the identification circuit 122 is transmitted to the internal bus via the IO circuit 123a. Signals on the internal bus can be output to the USB via the IO circuit 124, stored in the memory 151, or digital signal processed by the MPU 150.

  All measurement units can form a network topology that is connected in parallel to the central unit. For this reason, the number of measurement units can be freely increased / decreased within the range of the maximum accommodation channel for one overall unit. As the number of measurement units increases, the calculation processing amount of the overall unit increases, but the processing capability of the unit itself mounted on the subject is constant. Since the processing performance of the overall unit is normally allowed up to the upper limit in facility management, the requirements for compactness and power saving imposed on the subject wearing device are not applied. For this reason, there is no increase in the burden on the subject due to the increase in the number of measurement units other than the increase in the number of unit mounting locations. For this reason, a measurement system can be designed freely according to the purpose of measurement. Moreover, since each measurement unit is equipped with a battery, there is no change in the continuous measurement possible time due to an increase in the units.

  Also, as shown in FIG. 10, a plurality of measurement units can be grouped and attached to different subjects. At this time, the overall unit registers the measurement unit, the subject to be mounted, and the mounting location after mounting. For this reason, it is not necessary to physically correspond the measuring unit to be attached to the subject. Therefore, it is possible to flexibly cope with an increase / decrease in the number of subjects and an increase / decrease in the number of wearing.

  At this time, since the specifications of the measurement unit are unique, it is possible to provide a large-scale biological information sensing system at low cost by manufacturing and storing a large number of measurement units. Furthermore, the case where an individual measurement unit fails can be dealt with by replacing the failed measurement unit without shutting down the entire system. For this reason, it is easy to construct a highly reliable measurement system by preparing a replacement measurement unit in advance.

  Naturally, by using multiple control units as described above, it is possible to measure using the total measurement unit of the measurement units associated with each unit, and it is easy to greatly increase the number of subjects and measurement points. It is.

  Moreover, although the said several measurement unit is used for several test object, the structural example in the case of using one integrated unit with respect to these is shown in FIG. In FIG. 11, four measurement units are used for each of subjects A and B, but a total of eight can be managed by one control unit. As described above, the advantage of being controlled by one control unit is that different test items or subjects can be measured in a lump, and the system can be greatly simplified.

  The wireless biological information sensing system of the present invention can also be used as a wireless multi-person electroencephalogram measurement system. In this case, the wireless biological information sensing system 300 includes stimulus generation means 310 that operates according to a time reference signal. An impulse-like stimulus from the stimulus generating means is simultaneously given to a plurality of subjects, and a biological signal caused by the stimulus is measured by the measurement unit 200 and compared.

  This is used when, for example, the difference in the influence of some stimulus on the sensibility such as video and sound on a plurality of subjects or test animals is converted into data by the difference in the biological signal. With this system, for example, the influence of some video on the subject can be converted into data using differences in biological signals.

  For this purpose, as shown in FIG. 12, (1) an audio-visual information control device 312 that controls content in which a stimulus start marker is embedded is used. The main purpose of this apparatus is to set presentation conditions such as timing when a single intense stimulus or repeated minute stimulus of video or audio is presented to a subject or test animal. Also, (2) an audiovisual information display device 311 that displays content to a subject by visual, auditory, or both methods is used. The audiovisual information display device is not limited to a normal image display device and sound source, and includes white or monochromatic illumination, an ultrasonic source and an ultra-low frequency source, a disturbance source and a noise source that interfere with audiovisual. The audiovisual information display device 311 and the audiovisual information control device 312 constitute the stimulus generating means 310. (3) A stimulus marker detector 330 that is installed near the audiovisual information display device and detects a stimulus point from display information is used. This becomes an input means for inputting a stimulus start time point signal. This is because the stimulus that is actually displayed to the subject is temporally different from the stimulus marker embedded in the content from the audiovisual information control device due to a circuit delay or the like, and it is desirable that the stimulus be placed near the subject There is also. By detecting the information on the stimulation points presented on the display device in the same space as the subject, it is possible to remove the influence of circuit delay, propagation delay, and the like. The stimulus start time signal may be a signal synchronized with the stimulus, or a signal for notifying the disclosure time of the stimulus.

  FIG. 13 shows an example of brain waves for four persons acquired by the wireless biological information sensing system 300 that simultaneously measures the brain waves of a large number of people. Since the stimulus start point is accurate, event-related potentials such as P300 (brain nerve reaction related to alerting) can be simultaneously acquired for a large number of people.

  When measuring the electroencephalograms and electrocardiograms of a large number of people at the same time, an electrocardiograph having the same basic configuration as the electroencephalograph can be used. However, since the potential corresponding to the electrocardiogram is about 100 times larger than that of the electroencephalogram, it may be difficult to use a measurement unit optimized with an electroencephalograph. In this case, a measurement unit corresponding to both electrocardiogram and electroencephalogram can be constructed by increasing the resolution of the ADC and simultaneously reducing the gain of the signal amplifier to give a margin in the dynamic range. It should be noted that the difference between the measurement bands of the electrocardiogram and the electroencephalogram can be compensated by subjecting the time series digital data accumulated after the data acquisition to a computational filtering calculation process.

  The present invention is not limited to this, and can be easily applied to examinations introduced into examinations for cardiovascular diseases in medical institutions such as 12-lead electrocardiography (12ECG). In this case, four measurement units for limb guidance and six measurement units for chest guidance are used for one subject.

100 General Unit 101 Time Reference Generator 102 Local Oscillator 103 Modulator 104 Memory 105 Data Processor 106 Decoder 107 Detector 108 Circulator 109 Antenna 200 Measurement Unit 201 Time Reference Signal Demodulator 202 Controller 203 Sensor Electrode 204 Detector 205 Amplifier 206 Analog-to-digital (AD) converter 207 Modulator 208 Circulator 209 Antenna 210 Oscillator 220 Internal bus 221 Detection circuit 222 Identification circuit 223 Input / output (IO) circuit 227 Mixer (Mixer)
229 Voltage controlled oscillator (VCO)
230 Amplifier / rectifier 231 Voltage generator 232 Frequency divider 234 AD converter 236 AD converter 237 Operational amplifier 250 Control unit 251 Memory 252 System clock 260a Search electrode 260b Reference electrode 300 Wireless biological information sensing system 310 Stimulus generating means 311 Audiovisual information Display device 312 Audiovisual information control device 330 Stimulus marker detector

Claims (2)

A headquarters unit that distributes time standards,
A plurality of measuring units for receiving the time reference;
The overall unit receives transmission signals from a plurality of the measurement units, demodulates a biological signal, and stores, transmits, or displays the biological signal.
The plurality of measurement units include a sensor unit and a transmission / reception unit, and simultaneously perform biological signal measurement according to the output of a signal generator that can be phase-synchronized with a distributed time reference, and use frequency division multiplexing or code division multiplexing. The measurement data is transmitted wirelessly to the central unit while avoiding interference with each other .
Furthermore, a stimulus generating means that operates according to the time reference signal,
Giving the stimulus from the stimulus generating means to the test object,
Each of the measurement units measures a biological signal caused by the stimulus,
The stimulus generating means includes means for providing the measurement unit with a predetermined stimulus start time signal related to the start time of the stimulus,
The wireless biological information sensing system, wherein the overall unit includes input means for inputting the stimulus start time signal, and records the stimulus start time data input from the input means together with the measurement data. The wireless biometric information sensing system according to claim 1, wherein the stimulus start time signal is provided to the overall unit by the same presentation means as the stimulus presented by the stimulus generation means to the subject.

Images