JP5559019B2 - Wireless biological information sensor - Google Patents

Description

  The present invention relates to a wireless communication technique, and more particularly to a biological information transmission technique for continuously acquiring and transmitting biological information by a sensor.

Attention has been focused on a biological information sensor and a system for acquiring biological information continuously or intermittently by a sensor carried on a daily basis.
For example, Non-Patent Document 1 discloses a sensor that is carried on a daily basis and monitors biological information for the promotion and support of home medical care. The biometric information that is attracting attention is pulse, blood pressure, respiration, motion acceleration, blood oxygen saturation, etc., and the acquired information is registered in a portable sensor server that can be connected to the Internet line by wire or wirelessly. And sent to a server on the Internet. And finally, based on this information, doctors' diagnosis and services that can receive advice are mentioned.

A pulse wave is a wave generated when a change in blood pressure caused by contraction of the heart is transmitted to peripheral blood vessels, and is mainly caused by a change in arterial blood flow.
Pulse waves have been used in various ways, such as by calculating the pulse wave propagation velocity and calculating indices such as arrhythmia and other pulse diseases, and measuring the waveform period to calculate the pulse rate (heart rate). .
Furthermore, the pulse rate calculated from the pulse wave is considered to indicate the exercise load during exercise such as running, and the importance of continuous monitoring has been pointed out. Runners can exercise more safely by grasping their own pace while watching the pulse rate sequentially while running.

As a pulse wave measuring method, a photoelectric pulse wave measuring method is well known. For example, as shown in Non-Patent Document 2, the photoelectric pulse wave measurement method irradiates light on the blood vessel from the surface of the skin (for example, fingertip) from the light emitting element mounted on the pulse wave measurement device, The reflected light is measured by a light receiving element mounted in the same manner, and a pulse wave (volume pulse wave) is measured from the change in the amount of light.
The pulse wave measurement by the pulse wave measurement device is performed by the light emitting element that emits light to the measurement site and the light receiving element that receives the light reflected from the measurement site by a control device (microcomputer) mounted in the device. The process proceeds according to a predetermined processing flow such as a light receiving operation, a pulse wave information processing operation, and a pulse wave information display device (for example, a liquid crystal display).

The development of the wireless function unit responsible for wireless communication is not only in the development of hardware such as antennas and microcomputers, but also in various ways such as implementation of protocols in accordance with wireless communication standards, authentication of wireless communication standards, compliance with the Radio Law, etc. It takes time and development costs increase.
In order to reduce the development scale of the wireless function unit as much as possible in an apparatus having a function of wirelessly communicating data, in recent years, there is a high demand for adopting a product in which the core wireless function is modularized (integrated parts).

  As shown in Non-Patent Document 1 described above, attention is being paid to transmitting measured biological information by wireless communication from a measurement device that is carried and worn daily to a mobile phone or a mobile PC. Such data communication has been actively discussed in the Continua Health Alliance and others, and some have been determined as data communication standards using wireless communication systems such as Bluetooth (registered trademark) and Zigbee (registered trademark).

Itao et al., “Health Information System Using Wearable Sensors”, Information Processing Progressive Business Association, 2002 Results Report Imai et al., “Removal of body motion artifacts using acceleration sensor in photoelectric pulse wave measurement”, Biotechnology, vol.44, no.1, p.148-155, March 2006

A biological information sensor having a wireless communication function includes two sensors, a sensor unit that measures biological information and a wireless unit that wirelessly transmits biological information acquired by the sensor unit.
In order to continuously transmit biological information measured continuously, such as pulse waves, to an external device such as a portable sensor server, a mobile phone, or a mobile PC, the biological information measured by the sensor unit is transmitted to the wireless unit with good timing. Need to be passed. For this purpose, it is necessary to synchronize input / output of data related to biological information between the sensor unit and the wireless unit.

  In a biological information sensor in which a wireless unit carried by a wireless function module is mounted, there are two microcomputers: a sensor unit microcomputer (sensor microcomputer) and a wireless function module microcomputer (wireless microcomputer). Since wireless microcomputers are specialized in wireless communication and implemented as modules, those that are generally commercialized are low in cost but have low expandability, and the data with the sensor microcomputer of the biological information sensor is low. It cannot handle accurate synchronization for delivery.

For this reason, it is difficult to accurately synchronize between the sensor microcomputer and the wireless microcomputer. Therefore, it is difficult to continuously transmit biometric information data measured continuously without interruption.
In addition, in the wireless function module, in order to add a function for obtaining accurate synchronization for data exchange with the sensor microcomputer, there is a problem that the wireless microcomputer needs to be drastically modified and the development cost increases. .

  Based on the above circumstances, the present invention, in a biometric information sensor mounted with a wireless function module, in order to keep the development cost of the wireless function unit low, the data is bursted at regular intervals that are generally commercialized. It is an object of the present invention to provide a biological information transmission technique capable of continuously transmitting wireless information including pulse waves measured continuously on the premise of using a wireless module for transmission.

In order to achieve such an object, a wireless biological information sensor according to the present invention alternately selects a memory unit having two buffer memories and a buffer memory as a write destination from the memory units, and sequentially A sensor unit that writes the measured biological information to a buffer memory selected as a write destination and a buffer memory that is not selected as the write destination from among the memory units are alternately selected as a read-out buffer memory, and read. A wireless unit that reads out and wirelessly transmits the biological information from the buffer memory selected as a source at a speed faster than a speed at which the sensor unit writes the biological information, and the sensor unit includes all of the biological information Each time writing is completed, the buffer memory serving as the write destination from the memory unit The wireless unit suspends until the data storage time required for the sensor unit to write all of the biological information has elapsed from the previous switching selection after transmitting all the biological information. At the time when the data storage time has elapsed since the previous switching selection, the buffer memory serving as the reading source is alternately switched and selected from among the memory units .

Also, as the wireless unit, it may be provided with a plurality wireless unit different communication methods from each other.

According to the present invention, the biometric information is smoothly transferred from the sensor unit to the radio unit with a simple configuration without the buffer memory serving as the biometric information write destination and the buffer memory serving as the read source being balanced. Can do.
Therefore, it is possible to continuously wirelessly transmit biometric information such as continuously measured pulse waves without interruption without significantly changing the wireless module.

It is a block diagram which shows the structure of the wireless biometric information sensor concerning 1st Embodiment. It is explanatory drawing which shows the writing / reading operation | movement in a 1st state. It is explanatory drawing which shows the writing / reading operation | movement in a 2nd state. 6 is a timing chart showing write / read operations in a memory unit. It is an example of a monitor of pulse wave data. It is a signal waveform diagram showing the transmission operation and measurement operation of pulse wave data. It is a block diagram which shows the structure of the radio | wireless biometric information sensor concerning 2nd Embodiment.

Next, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
First, a wireless biological information sensor according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of the wireless biological information sensor according to the first embodiment.

  The wireless biological information sensor 100 is a sensor terminal device that is used as, for example, an exercise index measurement device or a medical device, and has a function of wirelessly transmitting biological information measured from a living body test unit to an external device 50 by wireless communication.

  In this embodiment, a plurality of buffer memories are provided in the wireless biometric information sensor 100, and the biometric information is sequentially measured and written to the buffer memory, and the biometric information is read from the buffer memory and transmitted wirelessly. One of the buffer memories is switched and selected as a biometric information write destination based on the selected selection order, and one of the buffer memories not selected as the write destination is selected as the biometric information read source based on the selection order. Are switched and selected.

  In the present invention, a case where the wireless biological information sensor 100 measures and transmits biological information composed of pulse wave data obtained by capturing a blood vessel volume change caused by blood inflow as a waveform from the body surface will be described as an example. It is not limited to. If the sensor element is changed, biological information such as acceleration, blood pressure, heart rate, body weight, body temperature, body fat, electrocardiogram, electromyogram, electroencephalogram, breathing, sweating, eye movement, saturated oxygen concentration, blood sugar, etc. are measured and transmitted. It is also possible to do.

  The wireless biological information sensor 100 includes a sensor unit 10, a memory unit 20, and a wireless unit 30 as main functional units. Here, a case where pulse waves are measured from a finger as biometric information and wirelessly transmitted will be described as an example.

The sensor unit 10 has a function of sequentially measuring biological information and writing it to the memory unit 20, and a sensor element 11, a processing circuit 12, and a sensor control unit 13 are provided as main circuit units.
The sensor element 11 is an element that measures biological information from a living body test part. Here, the sensor element 11 includes a light emitting element and a light receiving element. A light emitting element irradiates light to a living body test part. The irradiated light is scattered by the blood vessels in the living body test part. At this time, the light intensity of the scattered light changes in synchronization with the pulsation of the blood vessel. The light receiving element measures this change in light quantity.

The processing circuit 12 includes a signal processing circuit such as an A / D conversion circuit, and has a function of converting a measurement signal output from the sensor element 11 into biological information (data).
The sensor control unit 13 includes a control circuit such as a microcomputer that executes information processing by executing a program. Based on a predetermined selection order, the sensor control unit 13 stores one of the buffer memories 21 and 22 of the memory unit 20 as a living body. It has a function of switching and selecting as an information writing destination, and a function of writing biometric information output from the processing circuit 12 to the buffer memories 21 and 22 of the selected writing destination.

  The memory unit 20 includes a storage device such as a semiconductor memory, has a plurality of buffer memories 21 and 22, and has a function of temporarily storing biological information obtained by the sensor unit 10. Here, a case where two buffer memories 21 and 22 are provided will be described as an example.

The wireless unit 30 has a function of reading out biometric information from the memory unit 20 and wirelessly transmitting it, and a wireless module 31 is provided as a main circuit unit.
The wireless module 31 is a circuit unit that intermittently performs wireless communication using a general-purpose wireless communication method such as Bluetooth or Zigbee, and a wireless control unit 32 is provided as a main processing unit.

  The wireless control unit 32 includes a control circuit such as a microcomputer, and includes a control circuit such as a microcomputer that executes information processing by executing a program. The wireless control unit 32 serves as a write destination from the memory unit 20 based on a predetermined selection order. A function of switching and selecting any one of the unselected buffer memories as a reading source of the biological information, and reading the biological information from the selected reading source buffer memories 21 and 22 and wirelessly transmitting them to the external device 50 It has a function.

  In addition, the wireless biometric information sensor 100 includes a power supply unit that generates an operation power supply from a mounted secondary battery and supplies the operation power to each circuit unit, an operation input unit that detects a user operation, and an operation state LED Etc. are provided.

[Operation of First Embodiment]
Next, with reference to FIG. 2 and FIG. 3, operation | movement of the radio | wireless biometric information sensor 100 concerning this Embodiment is demonstrated. FIG. 2 is an explanatory diagram showing write / read operations in the first state. FIG. 3 is an explanatory diagram showing write / read operations in the second state.

  The sensor unit 10 drives the sensor element 11 and the processing circuit 12 in response to the activation of the wireless biometric information sensor 100 when the power is turned on, or in response to a measurement start operation by the user, and measures the biometric information from the living body test unit. Start the measurement operation.

  The sensor control unit 13 writes the biometric information in any one of the buffer memories 21 and 22 of the memory unit 20 based on a selection order determined in advance by its own memory or program in response to the start of the measurement operation. The switching is selected as the destination, and the biological information output from the processing circuit 12 is written into the buffer memory 21 or the buffer memory 22 of the selected writing destination.

  On the other hand, the radio control unit 32 of the radio unit 30 is not selected as a write destination from the memory unit 20 based on a selection order predetermined by its own memory or program according to the start of the measurement operation. One buffer memory 21 or buffer memory 22 is switched and selected as a biometric information reading source, and the biometric information is read from the selected reading source buffer memory 21 or buffer memory 22 and wirelessly transmitted.

  Therefore, when two buffer memories 21 and 22 are provided in the memory unit 20, one of the buffer memories is a write destination and the other buffer memory is a read source. In this case, since there are two buffer memories, the selection order is “buffer memory 21 → buffer memory 22”.

  That is, as shown in FIG. 2, in the first state in which the buffer memory 21 is selected as the write destination, the buffer memory 22 different from the buffer memory 21 is selected as the read source. Thereby, in the first state, the biological information is written to the buffer memory 21 by the sensor control unit 13, and the biological information is read from the buffer memory 22 by the wireless control unit 32.

  On the other hand, as shown in FIG. 3, in the second state in which the buffer memory 22 is selected as the write destination, the buffer memory 21 different from the buffer memory 22 is selected as the read source. Thereby, in the second state, the biological information is written to the buffer memory 22 by the sensor control unit 13, and the biological information is read from the buffer memory 21 by the wireless control unit 32.

  In this way, the first and second states transition based on the selection order, and the buffer memory that is the writing destination and the reading source of the biological information is switched and selected. For this reason, since it is possible to read out the biological information without waiting for the completion of writing of the biological information, it is possible to continuously wirelessly transmit the measured biological information while continuously measuring the biological information. .

  Here, the relationship between the wireless communication speed and the data storage speed derived from the state transition condition will be described with reference to FIG. FIG. 4 is a timing chart showing write / read operations in the memory unit. Here, the period from time T0 to time T1 corresponds to the first state in FIG. 2 described above, and the period from time T1 to time T2 corresponds to the second state in FIG. 3 described above. Thereafter, the first and second states are repeated.

  A state in which biometric information is written in all storage capacities, that is, a radio communication time TR required to read out all the biometric information from a memory-full memory buffer and wirelessly transmit it is defined as Q. When the communication speed is VR, TR = Q / VR. In this case, strictly speaking, the slower of the wireless communication speed and the memory buffer reading speed should be used as the VR, but in general, the wireless communication speed is much slower.

  On the other hand, the data storage time TW required to write biometric information to all of these storage capacities for a memory buffer with all the storage capacities is Q, and the sampling speed of biometric information is VW. In this case, TW = Q / VW. At this time, strictly speaking, the slower one of the sampling speed of the biological information and the writing speed of the memory buffer should be used as the VW, but in general, the sampling speed is much slower.

Here, the condition of the state transition for switching the buffer memory is that the biometric information is written by the sensor control unit 13 for one buffer memory and the memory becomes full, and the biometric data already stored by the wireless control unit 32 for the other buffer memory. All information is transmitted.
Therefore, when the wireless communication speed VR and the sampling speed VW are equal, the biological information is transferred smoothly.

On the other hand, since the measurement interval of biological information differs depending on the biological information to be measured, the sampling speed VW also changes. Further, the wireless communication speed VR also changes depending on the wireless communication method, the wireless communication environment, and the external device that is the communication partner. Furthermore, the radio communication speed VR and the sampling speed VW slightly change depending on the operation accuracy of the circuit.
Therefore, in many cases, the radio communication speed VR and the sampling speed VW are not equal, and therefore, the radio communication time TR and the data storage time TW are also different.

For this reason, it is necessary to exchange biological information in accordance with the longer time of the wireless communication time TR or the data storage time TW as the state transition interval switched by the buffer memory. That is, among the wireless communication processing by the wireless control unit 32 or the measurement processing by the sensor control unit 13, the one with the shorter processing time is temporarily stopped and it is necessary to wait for the one with the longer processing time.
However, when the biological information such as pulse wave data is measured in the wireless biological information sensor 100, it is required to continuously measure the biological information. Therefore, the measurement process in the sensor control unit 13 cannot be stopped. Therefore, in order to execute such an operation, the relationship between the wireless communication speed VR and the sampling speed VW needs to be VR> VW.

  Here, since the sampling speed VW is set in advance, the data storage time TW is known, and the sensor control unit 13 has completed the writing of the biological information to the selected buffer memory by the specified data amount. That is, when the data storage time TW has elapsed from the previous state transition, the next buffer memory is switched and selected.

  Therefore, after transmitting all the biological information stored in the buffer memory selected as the reading source, the wireless control unit 32 temporarily stops the process until the data storage time TW elapses from the previous state transition. Specifically, the data storage time TW may be measured with an internal timer of the radio control unit 32. Thereby, biometric information can be continuously delivered to the sensor control unit 13 and the wireless control unit 32 without adding a mechanism that synchronizes in real time.

  FIG. 5 is a monitor example of pulse wave data. Here, an example is shown in which the horizontal axis is time and the vertical axis is signal intensity, and pulse wave data transmitted by the wireless biological information sensor 100 according to the present embodiment is received and monitored by the external device 50. According to this, it can be seen that the pulse wave data indicating the expansion motion of the blood vessel according to the motion of the heart is wirelessly transmitted to the external device 50 with high accuracy without interruption.

  FIG. 6 is a signal waveform diagram showing a pulse wave data transmission operation and a measurement operation. Here, a monitoring result is shown in which a signal waveform indicating a transmission voltage that changes during transmission in the wireless module 31 and a signal waveform indicating a pulse wave measurement signal output from the sensor element 11 to the processing circuit 12 are simultaneously monitored. ing.

  In FIG. 6, a period during which the transmission voltage is greatly changed is a transmission period. During this transmission period, all pulse wave data in the buffer memory is read and wirelessly transmitted. Even during this transmission period, the pulse wave measurement signal continues without interruption, and it can be seen that the measurement processing by the sensor control unit 13 is executed in parallel with the wireless communication processing by the wireless control unit 32.

[Effect of the first embodiment]
As described above, in the present embodiment, a plurality of buffer memories 21 and 22 are provided in the memory unit 20, and the biological information is sequentially measured and written to the buffer memories 21 and 22 by the sensor unit 10, The wireless unit 30 reads biometric information from the buffer memories 21 and 22 and wirelessly transmits it to the external device 50. At this time, the sensor unit 10 selects one of the buffer memories 21 and 21 based on a predetermined selection order. 22 is selected as the biometric information writing destination, and the radio unit 30 switches and selects one of the buffer memories 21 and 22 not selected as the writing destination as the biometric information reading source based on the selection order. It is a thing.

As a result, the biometric information write destination buffer memory and the read source buffer memory smoothly transfer the biometric information from the sensor unit 10 to the radio unit 30 with a simple configuration without matching. be able to.
Therefore, it is possible to continuously wirelessly transmit biometric information including continuously measured pulse waves without interruption without significantly changing the wireless module 31.

  In this embodiment, the case where two buffer memories 21 and 22 are provided in the memory unit 20 and sequentially switched has been described as an example. However, the number of buffer memories is not limited to two, but three or more. These buffer memories may be controlled to be switched.

  In the present embodiment, the wireless unit 30 may read the biological information from the buffer memories 21 and 22 at a speed higher than the speed at which the sensor unit 10 writes the biological information to the buffer memories 21 and 22. Thereby, even when the wireless communication speed VR and the sampling speed VW are not equal, the biological information can be transferred stably.

[Second Embodiment]
Next, a wireless biological information sensor 100 according to a second embodiment of the present invention will be described with reference to FIG. FIG. 7 is a block diagram illustrating a configuration of the wireless biological information sensor according to the second embodiment.

In the first embodiment, the case where there is one external device 50 that is the transmission destination of the measured biological information has been described as an example. In the present embodiment, a case will be described in which measured biological information is transmitted to two external devices 50A and 50B.
As shown in FIG. 7, the wireless biological information sensor 100 according to the present embodiment includes a processing system A including a memory unit 20A and a wireless unit 30A, and a processing system B including a memory unit 20B and a wireless unit 30B. A plurality of sensors 10 are provided in parallel to the sensor unit 10.

Similarly to the memory unit 20 according to the first embodiment, the memory unit 20A includes two buffer memories 21A and 22A. Similarly, the memory unit 20B includes two buffer memories 21B and 22B. ing.
Similarly to the radio unit 30 according to the first embodiment, the radio unit 30A is provided with a radio module 31A having a radio control unit 32A, and the radio unit 30B is also a radio having a radio control unit 32B. A module 31B is provided. These wireless modules 31A and 31B have a function of performing wireless communication by respective individual wireless communication methods corresponding to the external devices 50A and 50B that are communication partners.

  Further, in the wireless biological information sensor 100 according to the present embodiment, the sensor unit 10 is provided as a common configuration for the processing systems A and B. Accordingly, the biological information measured by the sensor unit 10 in the same manner as in the first embodiment is written in both the memory units 20A and 20B.

  As for the writing of the biological information to the memory unit 20A by the sensor control unit 13 of the sensor unit 10, any one of the memory units 20A is selected based on a predetermined selection order as in the first embodiment. The two buffer memories 21A and 22A are switched and selected as the biometric information write destination, and the biometric information output from the processing circuit 12 is written to the selected write destination buffer memory 21A or buffer memory 22A.

  The same applies to the writing of the biological information to the memory unit 20B by the sensor control unit 13 of the sensor unit 10, and any one of the buffer memories 21B and 22B of the memory unit 20B is stored in the biological unit based on a predetermined selection order. The switch is selected as the information writing destination, and the biometric information output from the processing circuit 12 is written to the buffer memory 21B or the buffer memory 22B of the selected writing destination.

  Similarly to the first embodiment, the wireless control unit 32A of the wireless unit 30A uses any one buffer memory that is not selected as a write destination from among the memory units 20A based on a predetermined selection order. 21A or the buffer memory 22A is switched and selected as a biometric information read source, and the biometric information is read from the selected read source buffer memory 21A or buffer memory 22A and wirelessly transmitted to the external device 50A.

  Similarly, the radio control unit 32B of the radio unit 30B uses any one of the buffer memory 21B or the buffer memory 22B that is not selected as a writing destination from the memory unit 20B based on a predetermined selection order as biometric information. Is selected as a read source, and biometric information is read from the selected buffer memory 21B or buffer memory 22B, and wirelessly transmitted to the corresponding external device 50B.

[Effect of the second embodiment]
As described above, in the present embodiment, a plurality of processing systems including the memory unit 20 and the wireless unit 30 are provided in parallel to the sensor unit 10, and the memory unit 20 of each processing system is provided from the sensor unit 10. On the other hand, since the biological information is written in parallel, the biological information can be simultaneously transmitted to the plurality of external devices 50A and 50B in real time.
Further, the wireless module 30 of each processing system can select a wireless module 31 of an arbitrary wireless communication system, and simultaneously transmits biological information to the external devices 50A and 50B of different wireless communication systems in real time. It becomes possible.

[Extended embodiment]
The present invention has been described above with reference to the embodiments, but the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

  In the first embodiment described above, when the wireless unit 30 reads biological information from the buffer memories 21 and 22 at a speed higher than the speed at which the sensor unit 10 writes the biological information to the buffer memories 21 and 22, the wireless control unit The case where the state transition is performed by measuring the data storage time TW with 32 internal timers has been described as an example, but the present invention is not limited to this. For example, a switching signal generation unit that generates a switching signal for each data storage time TW may be provided separately, and state transition may be performed based on the switching signal from the switching signal generation unit. Further, this switching signal generation unit may be realized by the sensor control unit 13 using an internal timer.

  DESCRIPTION OF SYMBOLS 100 ... Wireless biometric information sensor, 10 ... Sensor part, 11 ... Sensor element, 12 ... Processing circuit, 13 ... Sensor control part, 20, 20A, 20B ... Memory part, 21, 21A, 21B, 22, 22A, 22B ... Buffer Memory, 30, 30A, 30B ... wireless unit, 31, 31A, 31B ... wireless module, 32, 32A, 32B ... wireless control unit, 33, 33A, 33B ... antenna, 50, 50A, 50B ... external device.

Claims (2)

A memory unit having two buffer memories;
A sensor unit that alternately switches and selects a buffer memory to be written from among the memory units, and sequentially writes the biological information measured to the buffer memory selected as the writing destination ,
A buffer memory that is not selected as the writing destination from among the memory units is alternately switched and selected as a reading source buffer memory, and from the buffer memory that is selected as the reading source, the sensor unit writes the biometric information at a speed higher than that. A wireless unit that reads out and wirelessly transmits the biological information at a high speed ,
The sensor unit alternately switches and selects the buffer memory to be the writing destination from the memory unit every time all writing of the biological information is completed ,
After transmitting all the biological information , the wireless unit pauses until the data storage time required for the sensor unit to write all of the biological information has elapsed from the previous switching selection, and The wireless biometric information sensor characterized by alternately switching and selecting the buffer memory to be the reading source from the memory unit when the data storage time has elapsed . The wireless biological information sensor according to claim 1 ,
A wireless biometric information sensor comprising a plurality of wireless units having different communication methods as the wireless unit.