JP6882073B2 - Biological signal recording device and its control method - Google Patents

Description

The present invention relates to a biological signal recording device and a control method thereof, and more particularly to a biological signal recording device for recording a plurality of types of biological signal data and a control method thereof.

Biological signal recording devices such as a Holta electrocardiograph and a portable sleep evaluation device (Patent Document 1) are known. These biological signal recording devices measure a plurality of types of biological signals over a long period of time, and record the data (biological signal data) and analysis results in a recording medium such as a built-in memory or a memory card.

Japanese Unexamined Patent Publication No. 2014-008159

The conventional biological signal recording device has a configuration in which each type of data to be recorded is recorded at a specific address in the built-in memory, and is not compatible with a generally used file system. Therefore, a dedicated application was required to read and refer to the data recorded in the built-in memory with an external device such as a personal computer. This is because management information needs to be updated during data recording in order to be compatible with the file system, but the NAND flash memory, which is often used as internal memory, cannot overwrite data. This is because a large amount of resources (for example, a large-capacity buffer memory) are required to achieve both high-speed data recording and management information update at the same time.

On the other hand, in a biometric signal recording device that can record data on a recording medium used in a general device such as a memory card, a format that can be handled as a data file by an external device after recording in the built-in memory is completed (file). Data was being copied to a memory card (in a format compatible with the system).

The present invention has been made in view of such problems of the prior art, and a main object thereof is to provide a biological signal recording device capable of recording biological signal data at high speed on a recording medium and a control method thereof. ..

The above-mentioned object is a biometric signal recording device that sequentially records biometric signal data obtained by measurement on a recording medium, and has a control means for controlling recording of the biometric signal data on the recording medium, and the recording medium is data. It is a recording medium whose data cannot be updated by overwriting, and the control means is a data area for storing the biometric signal data for the scheduled recording time and the biometric signal data for the scheduled recording time in the data area. A data file having a file management information area in which the file management information data corresponding to the stored state is recorded is generated before the start of recording the biometric signal data, and the biometric signal data is data without updating the file management information. It is achieved by a biometric signal recorder, characterized in that it sequentially records in a region.

With such a configuration, according to the present invention, it is possible to provide a biological signal recording device capable of recording biological signal data on a recording medium at high speed and a control method thereof.

It is a figure which shows the functional composition example of the portable sleep evaluation apparatus as an example of the biological signal recording apparatus which concerns on embodiment of this invention. It is a figure which shows the structural example of the biological signal data file recorded by the portable sleep evaluation apparatus which concerns on embodiment of this invention. It is a flowchart for demonstrating the operation example of the portable sleep evaluation apparatus which concerns on embodiment of this invention.

Hereinafter, the present invention will be described in detail with reference to the drawings based on an exemplary embodiment.
FIG. 1 is a block diagram showing a functional configuration example of a portable sleep evaluation device (hereinafter, simply referred to as a sleep evaluation device) 100 as an example of the biological signal recording device according to the embodiment of the present invention. The sleep evaluation device described here is a so-called simple polygraph inspection device, which measures a biological signal for evaluating the sleep of a subject and records biological signal data. In the present specification, the biological signal means a signal representing a state or activity of a living body. Biological signals include signals that are directly detected as electrical signals such as electrocardiogram signals and myocardial signals, and biological conditions and activities such as body temperature, respiratory waveforms, pulse waves, and snorting that can be handled by the device using sensors. Includes the converted signal.

(Constitution)
In the sleep evaluation device 100 according to the present embodiment, the SpO ₂ sensor 101 is a transmission type sensor that measures the arterial oxygen saturation (SpO ₂ ), for example, with the fingertips of a subject. The cannula 102 has an opening near the nostrils of the subject and is used to detect the nasal breathing waveform and snoring sound of the subject by the connected pressure sensor 106. The chest / abdominal sensor 103 is a sensor for detecting the respiratory effort movement of the subject.

The electrocardiogram electrode 104 is, for example, an electrode for detecting a unipolar or bipolar two-channel electrocardiogram signal. The accelerometer 105 is a sensor for determining the body position of the subject (for example, right lateral decubitus position, left lateral decubitus position, supine position, prone position, and standing position) and detecting body movement.

The memory 107 is a memory used by the control unit 110 for work, and is used, for example, as a buffer for temporarily storing measured biological signal data and as a video memory of the display unit 108. The non-volatile memory 113 is a non-removable built-in recording medium for recording the measured biological signal data, and is a NAND flash memory in the present embodiment. The display unit 108 has, for example, a liquid crystal display (LCD) and displays an operating status of the device, measurement waveforms, user information, GUI, and the like.

The control unit 110 includes, for example, one or more programmable processors (hereinafter, CPU), a rewritable ROM, and a RAM. The control unit 110 controls the operation of each part of the sleep evaluation device 100 by loading the program stored in the ROM into the RAM and executing it in the CPU, and realizes the function of the sleep evaluation device 100. In addition to the program executed by the CPU, various setting values, GUI data, etc. are stored in the ROM. The CPU may read the program stored in the non-volatile memory 113 into the memory 107 and execute the program.

The control unit 110 determines the total recordable time, recorded time and / or remaining recordable time of the sleep evaluation device 100, maximum recordable time per time, maximum recordable number of times, recorded number of times and / or remaining recordable number of times. The value related to the recording operation such as is held in the RAM or the memory 107 in the control unit 110, and is updated in accordance with the recording operation.

The input unit 109 is a general term for input devices used by users (medical personnel and subjects) to input various instructions and settings. The input unit 109 is an input device that does not require physical operation, such as an input device that requires physical operation such as a switch, a button, a dial, and a touch panel, as well as an input device that recognizes an instruction by voice recognition. Equipment can be included. The instruction input through the input unit 109 is detected by the control unit 110, and the control unit 110 executes an operation according to the instruction.

It should be noted that a sounding means such as a speaker may be provided so as to notify the user of the operating state of the device, the occurrence of an error, the operation procedure, etc. by voice or the like.

According to the control of the control unit 110, the recording unit 111 records the measured biological signal data on a memory card (MC) 1110 which is an example of a detachable recording medium, and reads out the data recorded on the memory card 1110. .. As will be described later, the sleep evaluation device 100 of the present embodiment can record the measured biological signal data in both the non-volatile memory 113 and the memory card 1110. The memory card 1110 uses a NAND flash memory.

The external I / F 112 is an interface for wired or wireless communication with an external device such as a personal computer. There are no particular restrictions on the types of external devices that can be connected and the communication protocol with the external devices.
The power supply unit 114 has a primary battery or a secondary battery, and supplies power to each unit including the control unit 110. The control unit 110 can measure the power supply voltage (battery voltage) of the power supply unit 114.

(Recording operation)
Next, the operation of recording the biological signal data in the sleep evaluation device of the present embodiment will be described. Since the purpose of this section is to explain the overall operation during recording, various sensors 101, 103 to 105 and a cannula 102 are attached to a predetermined part of the subject in advance, and the recording start condition is satisfied. It is assumed that the above is satisfied.

When the recording start instruction is input from the input unit 109, the control unit 110 writes the recording start date and time in the memory 107, and starts the measurement of the biological signal and the recording operation of the biological signal data. The control unit 110 applies predetermined processing such as A / D conversion and filter processing to the biological signals obtained from various sensors 101, 103 to 106 to generate biological signal data. The control unit 110 sequentially writes the generated biological signal data to the memory 107.

The pressure sensor 106 connected to the cannula 102 converts airflow from the nasal cannula or oral and nasal cannula into an electrical signal. The control unit 110 applies amplification processing and filtering processing to this electric signal, and displays the signal obtained from the pressure sensor 106 as a signal indicating a change in mask pressure depending on a frequency component, a signal indicating a respiratory waveform, and a tracheal sound (sniffing). Separate into signals. If the cannula is a nasal cannula, a nasal breathing waveform can be obtained, and if the cannula is a nasal cannula having an opening near the mouth, a nasal breathing waveform can be obtained.

For example, the control unit 110 obtains a signal amplified by applying a low-pass filter having a cutoff frequency of about 500 Hz with respect to the electric signal obtained from the pressure sensor 106 as a basic signal. Then, the control unit 110 obtains a signal to which a low-pass filter having a cutoff frequency of 2 to 3 Hz is further applied to the basic signal as a mask pressure signal. Further, the control unit 110 obtains a signal obtained by applying a high-pass filter having a cutoff frequency of 0.01 to 0.1 Hz and a low-pass filter having a cutoff frequency of 2 to 3 Hz to the basic signal as a breathing signal. Further, the control unit 110 obtains a signal obtained by applying a high-pass filter having a cutoff frequency of 0.01 to 0.1 Hz and a low-pass filter having a cutoff frequency of 150 to 200 Hz to the basic signal as a tracheal sound signal. These are examples of methods for separating various signals from the signal of the pressure sensor 106, and the frequency characteristics of the filter may be changed or other methods may be used.

Further, the control unit 110 outputs a respiratory-related signal of a signal indicating a change in mask pressure (mask pressure signal), a signal indicating a respiratory waveform (respiratory signal), and a signal indicating tracheal sound (sniffing) (tracheal sound signal), respectively. Convert the voltage value to the pressure value [cm H ₂ O] and record it.
In addition, the respiratory effort waveform is obtained from the chest / abdominal sensor. Although the suprasternal notch waveform is not measured in this embodiment, it may be configured to acquire the suprasternal notch waveform.

The control unit 110 sequentially writes the biological signal data to the memory 107 and analyzes the biological signal data. In the analysis process, the presence or absence of apnea or hypopnea section, duration and frequency, position and its change, _{presence or absence of decrease of SpO 2 by} a predetermined percentage (for example, 2 to 4%) or more, duration and frequency, pulse rate (maximum) , Minimum, average) and so on. For example, the control unit 110 indicates that apnea is a state in which breathing is stopped for 10 seconds or more, hypopnea is a state in which ventilation is clearly reduced (a state in which the amplitude of normal breathing is reduced by 30% or more is 10 seconds or more), and SpO ₂ Can be detected as a state in which is reduced by 3 to 4% or more. Since the analysis process can be performed by using a known method, further details will be omitted. The analysis process of the biological signal data may be executed by an external device.

The control unit 110 records the biological signal data stored in the memory 107 as a data file in the non-volatile memory 113 in a predetermined order for each predetermined unit time (first time). When the recording to the memory card 1110 is set, the control unit 110 also supplies the biological signal data to the recording unit 111, and records the biological signal data as a data file on the memory card 1110 as well. The control unit 110 also records the analysis result data in the non-volatile memory 113 (more memory card 1110 depending on the setting) every time the biological signal data for a predetermined time (second time) longer than the first time is recorded. ). The control unit 110 records biological signal data and analysis result data in the non-volatile memory 113 and the memory card 1110 as data files of the same format.

The control unit 110 can also display that recording is being performed on the display unit 108 during recording, a recording time, a scheduled recording end date and time, an attached state of a sensor or the like, a part of measured values, and the like.

The control unit 110 continuously executes the above-mentioned measurement processing, analysis processing, and recording processing until it is determined that the recording end condition is satisfied. When the control unit 110 reaches, for example, the set automatic recording end time (for example, 8 hours), or detects the input of the recording end instruction through the input unit 109, the remaining recordable time becomes 0. In this case, it can be determined that the recording end condition is satisfied when the recorded time reaches the total recordable time or when an abnormality related to the device is detected.

(Data file structure)
Next, the structure of the data file used by the sleep evaluation device 100 of the present embodiment for recording the biological signal data and the data of the analysis result will be described with reference to FIG. The non-volatile memory 113 and the memory card 1110 on which the sleep evaluation device 100 records data are recording media on which the data cannot be overwritten. Therefore, in order to realize continuous data recording, it is necessary to have a mechanism that prevents data update as much as possible.

In this embodiment, a plurality of types of biological signal data are collectively recorded in one data file. Hereinafter, different types of biological signal data will be referred to as "parameters". In the example shown in FIG. 2, the case where six types of parameters A to F are recorded is shown, but the number of parameters is not limited.

In the present embodiment, the data area for recording the parameters for the scheduled recording time set in advance and the file management information data in the state where the parameters for the scheduled recording time are recorded in the data area before starting the recording. A data file having a file management information data area in which the data is recorded is generated. After that, the parameters are recorded in the data area. Writing to the data area
-Individual parameters are sequentially recorded repeatedly every first time (10 seconds in the example of FIG. 2) -Individual parameters are recorded for the second time (10 minutes in the example of FIG. 2) and recorded. This is performed by repeatedly executing the procedure of recording the management information data (partial management information data) related to the parameters for the second time.

In addition, the file management information data corresponding to the generated data file is recorded at the beginning of the data file. The file management information data is management information used by the file system, and includes data related to the following information.
-Data size for the first time for each size information parameter Total data size for all parameters for the first time (201 in FIG. 2)
Total data size of all parameters for the second time (202 in FIG. 2)
Total data size and file recording information for the scheduled recording time (recording start date and time, recording end date and time, device identification number)
It is necessary to update the file management information data during data recording by recording the file management information data in the state where the parameters for the scheduled recording time are recorded in the data area before starting the data recording in the data area. Absent.

In addition, the partial management information data includes data related to the following information.
-Recorded date and time information-Recording end date and time information-End factor Partial management information data is used to update file management information data after recording is completed, especially when the actual recording time of the data is shorter than the scheduled recording time.
The information shown here is merely an example, and other data may be included in the respective management information.

Although the area for recording the analysis result data is omitted in FIG. 2, when the analysis result data is recorded, it can be periodically recorded immediately before the partial management information data.

In the present embodiment, the file management information data is not updated until the recording is completed, while the partial management information data is periodically recorded. Therefore, even if the recording is completed before the recording for the scheduled recording time is completed, the file management is performed so that the valid parameters recorded before the last recorded partial management information data can be used normally. Information data can be updated.

(File recording operation)
Next, the file recording operation in the sleep evaluation device 100 of the present embodiment will be described with reference to the flowchart shown in FIG. The operation shown in the flowchart of FIG. 3 is executed when the recording start instruction is detected.
Although the recording medium described here is assumed to be the non-volatile memory 113 (built-in memory), the memory card 1110 can also be recorded by the same processing.

In S101 to S103, the control unit 110 generates a data file for recording the parameters for the scheduled recording time in the non-volatile memory 113.
First, in S101, the control unit 110 erases (erases) the entire area (data file area) of the non-volatile memory 113 used for recording the biological signal data.

Next, in S102, the control unit 110 secures a data area having a capacity of the set recording time (scheduled recording time) in the data file area. The size of the data area required for recording the parameters for the scheduled recording time is, for example, the size information per unit time stored in the ROM of the control unit 110, the size information of the partial management information data, and the data of the analysis result. It can be calculated based on the size information.

In S103, the control unit 110 records the above-mentioned file management information data at the beginning of the data file area. This file management information data has contents corresponding to a data file in a state in which recording for the scheduled recording time is normally completed. That is, before starting the recording, the file management information data is recorded in anticipation that the recording for the scheduled recording time will be completed normally. As a result, it is not necessary to update the file management information data when the recording for the scheduled recording time is actually completed normally.

In S105 to S115, the control unit 110 records the parameter and partial management information data.
In S105, the control unit 110 determines whether or not the above-mentioned recording end condition is satisfied, and if it is determined that the recording end condition is satisfied, the process proceeds to S117, and if it is not determined that the recording end condition is satisfied, the process proceeds to S107.

In S107, the control unit 110 stores the generated biological signal data (parameter) in the memory 107.
In S109, the control unit 110 determines whether or not the parameters for the first time have been accumulated in the memory 107, proceeds to S111 if it is determined to be accumulated, and processes to S105 if it is not determined to be accumulated. Return.

In S111, the control unit 110 records the first time for each parameter in the data area. Corresponds to the recording of the parameters Ax to Fx (x is 1, 2, ...) In FIG. Recording to the non-volatile memory 113 is performed for each writing unit (for example, page) of the non-volatile memory 113. The recording offset address of each parameter can be calculated based on the size information included in the file management information data.

In S113, the control unit 110 determines whether or not the recording of the parameters for the second time (for example, the parameters A-1 to Fn in the example of FIG. 2) has been recorded in the data area of the data file, and records the parameters. If it is determined that the data has been recorded, the process proceeds to S115, and if it is not determined that the data has been recorded, the process returns to S105.

In S115, the control unit 110 records the partial management information data in the data area of the data file, and returns the process to S105. When recording the analysis result data, record it before the partial management information data.

In S117, the control unit 110 updates the file management information data so as to match the actual recorded data, and ends the process. It is not necessary to update the file management information data when the recording ends after the automatic recording end time is reached. On the other hand, when the recording is completed due to the recording end instruction or abnormality of the subject, the control unit 110 updates the file management information data based on the last recorded partial management information data. For example, the recording end date and time included in the file management information data is updated based on the information regarding the recording date and time included in the partial management information data. As a result, a normal data file containing data from the start of recording to the last recorded partial management information data can be obtained.

As described above, in the present embodiment, before starting the recording of the biological signal data, a data file having a data area for storing the biological signal data for the scheduled recording time is generated. Then, in the data file, the file management information data corresponding to the state in which the biological signal data for the scheduled recording time is stored in the data area is recorded. In this way, by sequentially recording the biological signal data in the data file in which the data area for storing the biological signal data for the scheduled recording time is secured before the start of recording, the file management information data is recorded during the recording of the biological signal data. It is not necessary to update the data, and biological signal data can be recorded at high speed without using a large-capacity buffer memory. Therefore, in a biological signal recording device that executes measurement and recording in parallel, data can be recorded in the form of a data file.

(Other embodiments)
The biological signal recording device according to the present invention is realized as a program (application software) for causing a generally available general-purpose information processing device such as a smartphone or tablet terminal to execute the operation described with reference to FIG. You can also do it. Therefore, such a program and a storage medium (an optical recording medium such as a CD-ROM or DVD-ROM, a magnetic recording medium such as a magnetic disk, a semiconductor memory card, etc.) in which the program is stored also constitute the present invention. ..

100 ... Portable sleep evaluation device, 110 ... Control unit, 111 ... Recording unit, 1110 ... Memory card, 113 ... Non-volatile memory, 114 ... Power supply unit

Claims (11)

A biological signal recording device that sequentially records biological signal data on a recording medium.
It has a control means for controlling the recording of the biological signal data on the recording medium, and has
The control means
File management information that records the data area for storing the biometric signal data for the scheduled recording time and the file management information data corresponding to the state in which the biometric signal data for the scheduled recording time is stored in the data area. A data file having a data area is generated before the start of recording the biometric signal data.
The biological signal data is sequentially recorded in the data area without updating the file management information data.
A biological signal recording device characterized by this. The biological signal recording device according to claim 1, wherein the recording medium is a recording medium in which the data cannot be updated by overwriting the data. The control means 1 or 2 is characterized in that when the actual recording time of the biological signal data is shorter than the scheduled recording time, the file management information data is updated after the recording of the biological signal data is completed. The biological signal recording device according to. The control means
Every time the biological signal data for a predetermined time is recorded, the partial management information data related to the biological signal data for the predetermined time is recorded in the data area.
When the actual recording time of the biological signal data is shorter than the scheduled recording time, the file management information data is updated based on the last recorded partial management information data after the recording of the biological signal data is completed.
The biological signal recording device according to any one of claims 1 to 3, wherein the biological signal recording device is characterized. The biological signal recording device according to claim 4, wherein the file management information data includes size information of the biological signal data for the predetermined time. The partial management information data includes information regarding the recording date and time of the corresponding biological signal data.
4. The control means is characterized in that the recording end date and time included in the file management information data is updated based on the information regarding the recording date and time included in the partial management information data recorded last. Alternatively, the biological signal recording device according to claim 5. When the biological signal data is composed of a plurality of types of data, the control means sequentially records the plurality of types of data in the data area in a predetermined order for a predetermined unit time. The biological signal recording device according to any one of claims 1 to 6. The biological signal recording apparatus according to claim 7, wherein the file management information data includes information on the data size for the unit time for each of the plurality of types of data. The biological signal recording apparatus according to claim 7, wherein the file management information data includes information on the total data size of the plurality of types of data for the unit time. It is a control method of a biological signal recording device that sequentially records biological signal data on a recording medium.
File management information that records the data area for storing the biometric signal data for the scheduled recording time and the file management information data corresponding to the state in which the biometric signal data for the scheduled recording time is stored in the data area. A generation step of generating a data file having a data area before starting recording of the biometric signal data, and
A recording step of sequentially recording the biological signal data in the data area without updating the file management information data, and
A method for controlling a biological signal recording device. A program for causing a computer included in a biological signal recording device to function as a control means included in the biological signal recording device according to any one of claims 1 to 9.

Images