No-motion state determination system, no-motion state determination method, and program

Abstract

A motionless state determination system, a motionless state determination method, and a program are provided that can stably determine, using a Doppler sensor, that a subject is not exhibiting expected motion. [Solution] A Doppler data acquisition unit 20 repeatedly acquires Doppler data indicating the measurement results by a Doppler sensor 12 provided facing the subject. A change rate calculation unit 22 calculates the change rate of the Doppler data value at each of a plurality of consecutive time points. A motionless state determination unit 26 determines that the subject is not exhibiting an expected motion based on the change rate at each of the plurality of time points.

Description

[Technical field]

[0001] The present invention relates to a motionless state determination system, a motionless state determination method, and a program, and more particularly to a system for determining whether a subject is not exhibiting a desired motion based on Doppler data. [Background technology]

[0002] Various systems are being considered that measure the respiration rate and heart rate of a subject based on Doppler data obtained by a Doppler sensor. As an example of such a system, Patent Document 1 describes a monitoring device that determines the respiration rate and heart rate in a non-contact manner using a microwave Doppler sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-134795 A Summary of the Invention [Problem to be solved by the invention]

[0004] The inventor is considering using a Doppler sensor to determine whether the subject is not performing the expected motion. Specifically, for example, the inventor is considering determining whether the subject is in an apneic state or has bradycardial arrhythmia. Here, it is considered to determine that the subject is not performing the expected motion when the amplitude of Doppler data, which is the measurement result by the Doppler sensor, is small.

[0005] However, for example, when the person being measured is located far away from the Doppler sensor, the amplitude of the Doppler data may become small. Therefore, when the above-mentioned judgment is performed, there is a risk of erroneously judging that the person being measured is not exhibiting the expected movement even though the person is actually exhibiting the expected movement. In addition, when the threshold value used to judge that the person being measured is not exhibiting the expected movement is not appropriate, there is a risk of erroneously judging that the person being measured is exhibiting the expected movement even though the person is not exhibiting the expected movement.

[0006] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a motionless state determination system, a motionless state determination method, and a program that can reliably determine whether a subject is not exhibiting expected movement using a Doppler sensor. [Means for solving the problem]

[0007] (1) The motionless state determination system of the present invention includes an acquisition means for repeatedly acquiring Doppler data indicating measurement results by a Doppler sensor provided toward the subject, a change rate calculation means for calculating a rate of change of the value of the Doppler data at each of a number of consecutive time points, and a motionless state determination means for determining that the subject is not exhibiting expected movement based on the rate of change at each of the number of time points.

[0008] (2) In the motionless state determination system described in (1), a time window change rate sum calculation means may be further included which calculates, for each of a plurality of time windows each including a first predetermined number of consecutive time points, the sum of the absolute values ​​of the change rates at each of the first predetermined number of time points included in the time window as a time window change rate sum corresponding to the time window, and the motionless state determination means may determine that the subject is not exhibiting an expected movement based on the average, sum, or variance of the time window change rate sums corresponding to each of a second predetermined number of consecutive time windows.

[0009] (3) In the motionless state determination system described in (1), the motionless state determination means may determine that the subject is not exhibiting an expected movement based on the average, sum, or variance of the absolute values ​​of the rate of change at each of the multiple time points.

[0010] (4) In the motionless state determination system described in (1), the motionless state determination means may determine that the subject is not exhibiting an expected movement based on the variance of the rate of change at each of the multiple time points.

[0011] (5) In the motionless state determination system described in any one of (1) to (4), the change rate calculation means may calculate a change rate of the Doppler data value at each of the multiple time points for each of the multiple Doppler sensors, and the motionless state determination means may determine that the subject is not exhibiting an expected movement based on the change rate calculated for each of the multiple Doppler sensors.

[0012] (6) The motionless state determination system described in (5) may further include an individual time window change rate sum calculation means for calculating, for each of a plurality of time windows each including a first predetermined number of consecutive time points for each of the plurality of Doppler sensors, a sum of the absolute values ​​of the change rates at each of the first predetermined number of time points included in the time window as an individual time window change rate sum corresponding to the time window, and a time window change rate sum calculation means for calculating, for each of the plurality of time windows, a sum of the individual time window change rate sums corresponding to the time window of each of the plurality of Doppler sensors as a time window change rate sum corresponding to the time window, and the motionless state determination means may determine that the subject is not exhibiting an expected movement based on an average, sum, or variance of the time window change rate sums corresponding to each of a second predetermined number of consecutive time windows.

[0013] (7) The motionless state determination system described in (5) may further include a time point change rate total calculation means for calculating, for each of the plurality of time points, the sum of the absolute values ​​of the change rates of each of the plurality of Doppler sensors as a time point change rate total corresponding to that time point, and a time window change rate total calculation means for calculating, for each of a plurality of time windows each including a first predetermined number of consecutive time points, the sum of the time point change rate totals at each of the first predetermined number of time points included in the time window as a time window change rate total corresponding to the time window, and the motionless state determination means may determine that the subject is not exhibiting an expected movement based on the average, sum, or variance of the time window change rate totals corresponding to each of a second predetermined number of consecutive time windows.

[0014] (8) In the motionless state determination system described in (5), the system may further include a time point change rate total calculation means for calculating, for each of the multiple time points, the sum of the absolute values ​​of the change rates of each of the multiple Doppler sensors as a time point change rate total corresponding to that time point, and the motionless state determination means may determine that the subject is not exhibiting an expected movement based on the average, sum, or variance of the time point change rate totals corresponding to each of the multiple time points.

[0015] (9) In the motionless state determination system described in (5), the system may further include a variance calculation means for calculating the variance of the rate of change of the Doppler data value at each of the multiple time points for each of the multiple Doppler sensors, and the motionless state determination means may determine that the subject is not exhibiting an expected movement based on the average or sum of the variances of the rate of change for each of the multiple Doppler sensors.

[0016] (10) In the motionless state determination system according to any one of (1) to (9), the motionless state determination means may determine whether the subject is in an apnea state.

[0017] (11) In the motionless state determination system according to any one of (1) to (10), the motionless state determination means may determine whether the subject has bradyarrhythmia.

[0018] (12) The motionless state determination method of the present invention includes the steps of repeatedly acquiring Doppler data indicating measurement results by a Doppler sensor provided toward the subject, calculating a rate of change of the value of the Doppler data at each of a number of consecutive points in time, and determining that the subject is not exhibiting an expected movement based on the rate of change at each of the number of points in time.

[0019] (13) A program according to the present invention is a program for causing a computer to execute the steps of repeatedly acquiring Doppler data indicating the results of measurement by a Doppler sensor provided facing a subject, calculating a rate of change in the value of the Doppler data at each of a plurality of consecutive time points, and determining that the subject is not exhibiting an expected movement based on the rate of change at each of the plurality of time points. This program may be stored in a computer-readable information storage medium. Effect of the Invention

[0020] According to the present invention, it is possible to stably determine, using a Doppler sensor, whether a subject is not exhibiting an expected movement. [Brief description of the drawings]

[0021] [Figure 1] 1 is a configuration diagram of a motionless state determination system according to an embodiment of the present invention. [Diagram 2] 1 is a functional block diagram of a signal processing device according to an embodiment of the present invention. [Diagram 3] 4 is a flowchart showing an example of a flow of processing performed in a signal processing device according to an embodiment of the present invention. FIG. [Figure 4] FIG. 2 is a diagram illustrating an example of a small time window and a large time window. [Figure 5A] FIG. 10 is a diagram illustrating an example of a change in the value of Doppler data. [Figure 5B] FIG. 10 is a diagram illustrating an example of a change in the value of Doppler data. [Figure 6A] FIG. 11 is a diagram illustrating an example of a change in the value of a judgment index. [Figure 6B] FIG. 11 is a diagram illustrating an example of a change in the value of a judgment index. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0023] Fig. 1 is a configuration diagram of a motionless state determination system 1 according to an embodiment of the present invention. As shown in the figure, the motionless state determination system 1 includes a signal processing device 10 and a Doppler sensor 12. As shown in Fig. 1, the Doppler sensor 12 is provided facing the subject.

[0024] 1, the Doppler sensor 12 is attached to the headboard of the bed 14. The motionless state determination system 1 according to this embodiment may include multiple Doppler sensors 12. The multiple Doppler sensors 12 may be provided symmetrically with respect to the center line of the bed 14 (a line passing through the center of the width of the bed 14 and extending in the length direction of the bed 14). The multiple Doppler sensors 12 may be provided aligned perpendicular to the length direction of the bed 14 (a direction along the center line of the bed 14). The multiple Doppler sensors 12 may be provided aligned in a row at equal intervals.

[0025] Doppler sensor 12 is provided so as to face the lengthwise direction (longitudinal direction) of bed 14, and emits microwaves in the lengthwise direction of bed 14. The microwaves are reflected by the chest of the person being measured sleeping on bed 14, and the reflected waves are received by Doppler sensor 12. Doppler sensor 12 generates a Doppler signal from the reflected waves that indicates chest movement associated with breathing, and outputs Doppler data that is a digitalized version of this Doppler signal. The microwaves emitted from Doppler sensor 12 have a slight difference in frequency, which prevents mutual interference.

[0026] The reflected wave is frequency shifted due to the Doppler effect, and by observing this, the breathing rate of the subject can be obtained. The reflected wave is detected by quadrature detection as a Doppler signal including an I signal, which is an in-phase component with the transmitted wave, and a Q signal, which is an orthogonal component, and output in digital form to the signal processing device 10. The Doppler signal input to the signal processing device 10 is time-series data, and indicates the amplitude (I component and Q component) at each time.

[0027] The signal processing device 10 may be configured by a known computer including, for example, a CPU, a memory, an input device and a display, and generates the respiration rate of the subject based on the Doppler signal output from the Doppler sensor 12.

[0028] 2 is a functional block diagram of a signal processing device 10 according to an embodiment of the present invention. As shown in the figure, the signal processing device 10 includes a Doppler data acquisition unit 20, a change rate calculation unit 22, a judgment index calculation unit 24, and a motionless state judgment unit 26. These functional blocks are realized by executing a signal processing program in the signal processing device 10, which is a computer. This signal processing program may be stored in various computer-readable information storage media such as a semiconductor memory and loaded from the medium to the signal processing device 10. Alternatively, it may be downloaded to the signal processing device 10 via a data communication line such as the Internet.

[0029] The Doppler data acquiring unit 20 repeatedly acquires Doppler data indicating the measurement results by the Doppler sensor 12 provided facing the subject, for example. Here, the Doppler data acquiring unit 20 may repeatedly acquire Doppler data indicating the measurement results by the Doppler sensor 12 from each of the multiple Doppler sensors 12. Here, the value of the Doppler data acquired by the Doppler data acquiring unit 20 may be a value obtained by performing pre-processing (data processing) such as cutting off the DC component, filtering, and various kinds of correction on the measurement result itself (raw data).

[0030] The change rate calculation unit 22 calculates, for example, the rate of change of the value of the Doppler data at each of a plurality of consecutive time points. Here, the change rate calculation unit 22 may calculate the rate of change of the value of the Doppler data at each of a plurality of consecutive time points for each of the plurality of Doppler sensors 12. The rate of change corresponds to, for example, the slope of a tangent in a graph of the value of the Doppler data. In this embodiment, the rate of change is calculated for each of the I data and the Q data.

[0031] For example, the latest Doppler data is acquired at 1 millisecond intervals, and the rate of change is determined at 10 millisecond intervals. In this case, the change rate calculation unit 22 may use the least squares method to calculate an approximation curve (which may be an approximation line) of the values ​​of the Doppler data from a predetermined time before a certain point in time (e.g., 5 milliseconds before) to a predetermined time after the point in time (e.g., 5 milliseconds after). Then, the change rate calculation unit 22 may determine the slope of the approximation curve (which may be an approximation line) at the point in time as the rate of change at the point in time.

[0032] The method of calculating the rate of change is not limited to the above. For example, a value may be calculated by subtracting the value of Doppler data a predetermined time (e.g., 1 millisecond) before a certain point in time from the value of Doppler data a predetermined time after the point in time. The calculated value may then be determined as the rate of change at the point in time. Alternatively, the calculated value may be divided by the time difference (e.g., 2 milliseconds) and determined as the rate of change at the point in time.

[0033] The judgment index calculation unit 24 calculates the value of the judgment index used to determine whether the subject is not performing the expected movement, for example, based on the rate of change calculated by the rate of change calculation unit 22. Here, an example of determining whether the subject is not performing the expected movement is determining whether the subject is in an apnea state. That is, the judgment index calculation unit 24 may calculate the value of the judgment index used to determine whether the subject is in an apnea state or not.

[0034] The motionless state determination unit 26 determines whether the subject is not moving as expected, for example, based on the rate of change in the value of the Doppler data at each of a plurality of consecutive time points. Here, the motionless state determination unit 26 may determine whether the subject is in an apnea state based on the rate of change in the value of the Doppler data at each of a plurality of consecutive time points. The motionless state determination unit 26 may also determine whether the subject is in an apnea state based on the rate of change in the value of the Doppler data at each of a plurality of consecutive time points calculated for each of the plurality of Doppler sensors 12. The motionless state determination unit 26 may also determine whether the subject is in an apnea state based on the value of the determination index calculated by the determination index calculation unit 24.

[0035] Here, an example of the flow of apnea state determination processing performed by the signal processing device 10 will be described with reference to a flow diagram shown in FIG.

[0036] First, the change rate calculation unit 22 calculates the change rate at each of a plurality of consecutive time points at a predetermined time interval (e.g., 10 millisecond intervals) for each of the plurality of Doppler sensors 12 (S101). Hereinafter, the time points at which the change rate is calculated will be referred to as the change rate calculation time points. In this embodiment, the change rate calculation time points are common to the plurality of Doppler sensors 12.

[0037] Then, for each of a plurality of small time windows SW (see FIG. 4) each including a first predetermined number (e.g., 10) of consecutive change rate calculation time points for each of the plurality of Doppler sensors 12, the determination index calculation unit 24 calculates the sum of the absolute values ​​of the change rates at each of the first predetermined number of change rate calculation time points included in the small time window SW as an individual time window change rate sum corresponding to the small time window SW (S102). Here, the sum of the absolute values ​​of the change rates of the I data and the Q data at each of the first predetermined number of change rate calculation time points included in the small time window SW may be calculated as the individual time window change rate sum corresponding to the small time window SW.

[0038] Then, for each of a second predetermined number (e.g., 100) of consecutive small time windows SW, the judgment index calculation unit 24 calculates the sum of the individual time window change rate sums corresponding to that small time window SW of each of the multiple Doppler sensors 12 as the time window change rate sum corresponding to that small time window SW (S103).

[0039] Then, the determination index calculation unit 24 calculates a value of a determination index used to determine whether or not the subject is in an apneic state (S104). In the process shown in S104, for example, the average, sum, or variance of the time window change rate totals corresponding to each of the second predetermined number of consecutive small time windows SW may be calculated as the value of the determination index corresponding to the large time window LW (see FIG. 4) including the second predetermined number of small time windows SW.

[0040] Fig. 4 shows a schematic diagram of 100 consecutive small time windows SW, SW(1) to SW(100). In this embodiment, the start timing of each small time window SW is shifted by the above-mentioned predetermined time (e.g., 10 milliseconds). As shown in Fig. 4, the time ranges covered by adjacent small time windows SW may overlap partially. Fig. 4 also shows a schematic diagram of a large time window LW including 100 consecutive small time windows SW.

[0041] Then, the motionless state determination unit 26 determines whether or not the subject is in an apneic state based on the value of the determination index calculated in the process shown in S104 (S105), and the process shown in this processing example is terminated.

[0042] In the process shown in S105, for example, if the value of the judgment index corresponding to the large time window LW calculated in the process shown in S104 is equal to or less than a predetermined threshold, it may be determined that the subject is in an apneic state during the period covered by the large time window LW.

[0043] In this embodiment, the length of the time range covered by the small time window SW may be equal to or longer than the duration of one breath. For example, the length of the time range covered by the small time window SW may be 3 seconds, 5 seconds, or the like.

[0044] Furthermore, although the first predetermined number and the second predetermined number in the above description are different, the first predetermined number and the second predetermined number may be the same.

[0045] In addition, in the process shown in S102, the judgment index calculation unit 24 may calculate the sum of the absolute values ​​of the change rates of each of the multiple Doppler sensors 12 for each of multiple consecutive change rate calculation points in time as the time point change rate total corresponding to that point in time.

[0046] Then, in the processing shown in S103, the judgment index calculation unit 24 may calculate, for each of a plurality of small time windows SW each including a first predetermined number (e.g., 10) of consecutive change rate judgment points, the sum of the point-in-time change rate sums at each of the first predetermined number of change rate judgment points included in the small time window SW as the time window change rate sum corresponding to the small time window SW.

[0047] Then, thereafter, the above-mentioned processes shown in S104 and S105 may be executed.

[0048] Furthermore, in this embodiment, it is not necessary to calculate the value of the judgment index corresponding to the large time window LW based on the time window change rate sum corresponding to the small time window SW.

[0049] For example, after the processing shown in S101, the judgment index calculation unit 24 may calculate the sum of the absolute values ​​of the change rates of each of the multiple Doppler sensors 12 for each of multiple consecutive (e.g., 100) change rate calculation points in time as the time point change rate total corresponding to that point in time.

[0050] Then, the judgment index calculation unit 24 may calculate the average, sum, or variance of the time-point change rate totals corresponding to each of the multiple (e.g., 100) change rate calculation time points as the judgment index value corresponding to a time window that includes the multiple change rate calculation time points.

[0051] Then, similarly to the process shown in S105, the motionless state determination unit 26 may determine whether or not the subject is in an apnea state based on the value of the determination index calculated in this manner. For example, when the value of the determination index corresponding to the time window is equal to or smaller than a predetermined threshold, it may be determined that the subject is in an apnea state during the period covered by the time window.

[0052] Furthermore, in this embodiment, it is not necessary to determine whether the person being measured is in an apneic state based on the absolute value of the rate of change.

[0053] For example, after the process shown in S101, the determination index calculation unit 24 may calculate, for each of the multiple Doppler sensors 12, the variance of the rate of change of the Doppler data value at each of multiple consecutive time points at which the rate of change is calculated.

[0054] Then, the judgment index calculation unit 24 may calculate the average or sum of the variances of the change rates in each of the multiple Doppler sensors 12 as the value of the judgment index corresponding to a time window that includes the multiple change rate calculation time points.

[0055] Then, similarly to the process shown in S105, the motionless state determination unit 26 may determine whether or not the subject is in an apnea state based on the value of the determination index calculated in this manner. For example, when the value of the determination index corresponding to the time window is equal to or smaller than a predetermined threshold, it may be determined that the subject is in an apnea state during the period covered by the time window.

[0056] In addition, when the motionless state determination system 1 according to this embodiment includes only one Doppler sensor 12, the rate of change of the value of that one Doppler sensor 12 at each of a number of consecutive change rate determination points may be calculated.

[0057] Then, for each of a plurality of small time windows SW each including a first predetermined number of consecutive change rate determination time points, the sum of the absolute values ​​of the change rates at each of the first predetermined number of change rate determination time points included in the small time window SW may be calculated as a time window change rate total corresponding to the small time window SW. Then, the average, sum, or variance of the time window change rate totals corresponding to each of a second predetermined number of consecutive small time windows SW may be calculated as a judgment index value corresponding to a large time window LW including the second predetermined number of small time windows SW. Then, based on the calculated judgment index value, it may be determined whether the subject is in an apneic state during a period covered by the large time window LW.

[0058] Alternatively, the average, sum, or variance of the absolute values ​​of the change rates at each of a plurality of consecutive change rate calculation time points may be calculated as the value of the judgment index corresponding to the time window including the plurality of change rate calculation time points. Then, based on the calculated judgment index value, it may be determined whether the subject is in an apneic state during the period covered by the time window.

[0059] Alternatively, the variance of the change rate at each of a plurality of consecutive change rate calculation time points may be calculated as a judgment index value corresponding to a time window including the plurality of change rate calculation time points. Then, based on the calculated judgment index value, it may be determined whether the subject is in an apneic state during a period covered by the time window.

[0060] 5A and 5B are diagrams showing an example of a change in the value of Doppler data. The horizontal axis represents date and time t, and the vertical axis represents the value x of Doppler data. It is assumed that the subject is not in an apneic state during period P1, and is in an apneic state during period P2.

[0061] In the situation shown in Fig. 5B, the amplitude of the Doppler data is smaller than that in the situation shown in Fig. 5A. For example, when the subject is located far away from the Doppler sensor 12, a situation occurs in which the amplitude of the Doppler data is small, as shown in Fig. 5B.

[0062] Here, for example, if a state in which the amplitude of the Doppler data is smaller than a predetermined threshold th1 (a state in which the value of the Doppler data is greater than -th1 and smaller than th1) continues for a predetermined period of time or more, it may be determined that the subject is in an apneic state.

[0063] In this determination, when the value of the Doppler data in period P2 is greater than threshold th1 as shown in Fig. 5A, the subject is determined not to be in an apneic state even though he or she is in an apneic state during period P2. Also, when the value of the Doppler data in period P1 is less than threshold th1 as shown in Fig. 5B, the subject is determined to be in an apneic state even though he or she is not in an apneic state during period P1.

[0064] In this way, the method of determining whether or not the subject is in an apneic state based on the amplitude of Doppler data cannot reliably determine whether or not the subject is in an apneic state.

[0065] 6A and 6B are diagrams showing an example of the change in the value of the judgment index based on the rate of change of the value of the Doppler data at each of a plurality of consecutive time points. The horizontal axis represents the date and time t, and the vertical axis represents the value y of the judgment index. As in the cases of FIGS. 5A and 5B, the subject is not in an apneic state during period P1, and is in an apneic state during period P2. The situation shown in FIG. 6B has a smaller amplitude of the Doppler data than the situation shown in FIG. 6A.

[0066] As shown in Figures 6A and 6B, when the subject is in an apneic state, the value y of the above-mentioned judgment index is approximately zero, regardless of the magnitude of the amplitude of the Doppler data when the subject is not in an apneic state.

[0067] Therefore, according to this embodiment, regardless of the amplitude of the Doppler data during period P1, a predetermined threshold th2 is appropriately set as shown in Figures 6A and 6B, and whether or not the subject is in an apneic state is determined based on whether or not the threshold th2 is exceeded, making it possible to stably determine whether or not the subject is in an apneic state regardless of the magnitude of the amplitude of the Doppler data during period P1.

[0068] The present invention is not limited to the above-described embodiment, and various modifications are possible.

[0069] For example, the present invention may be used to determine whether a subject has bradyarrhythmia.

[0070] In this case, the microwaves emitted from the Doppler sensor 12 may be reflected by the heart of the subject sleeping on the bed 14, and the reflected waves may be received by the Doppler sensor 12. Then, the signal processing device 10 may generate the heart rate of the subject based on the Doppler signal output from the Doppler sensor 12.

[0071] Then, the subject may be judged to have bradyarrhythmia or not by the same method as the method for judging whether the subject is in an apneic state as described above. In judging whether the subject is in a bradyarrhythmia or not, a time window (e.g., a time window of a different size) may be used different from the time window used to judge whether the subject is in an apneic state or not. In this case, the integral value of the spectrum obtained by performing a short-time Fourier transform (STFFT) on the value of the Doppler data used to judge whether the subject is in an apneic state or not may be used as the value of the Doppler data acquired by the Doppler data acquisition unit 20 in judging whether the subject is in a bradyarrhythmia or not. In this case, the judgment that the subject is in a bradyarrhythmia corresponds to an example of the judgment that the subject is not performing the expected movement. In this way, it is possible to stably judge whether the subject is in a bradyarrhythmia or not regardless of the magnitude of the amplitude of the Doppler data.

[0072] As described above, according to this embodiment, it is possible to stably determine, using the Doppler sensor 12, whether the subject is not exhibiting the expected movement (for example, whether the subject is in an apneic state, whether the subject is suffering from bradycardial arrhythmia, etc.).

[0073] In addition, in this embodiment, it may be determined whether the subject is in an apneic state and whether the subject has bradyarrhythmia. In addition, in this embodiment, when it is determined that the subject is in an apneic state, it may be determined whether the subject has bradyarrhythmia using the Doppler data used to determine whether the subject is in an apneic state. In this case, the integral value of the spectrum obtained by performing a short-time Fourier transform (STFFT) on the value of the Doppler data used to determine whether the subject is in an apneic state may be used as the value of the Doppler data acquired by the Doppler data acquisition unit 20 in determining whether the subject has bradyarrhythmia. Since there is a tendency that a subject with apnea syndrome is highly likely to also have bradyarrhythmia, this makes it possible to efficiently determine whether the subject has bradyarrhythmia. [Explanation of symbols]

[0074] 1 motionless state determination system, 10 signal processing device, 12 Doppler sensor, 14 bed, 20 Doppler data acquisition unit, 22 rate of change calculation unit, 24 determination index calculation unit, 26 motionless state determination unit.

Claims

1. an acquisition means for repeatedly acquiring Doppler data indicating a measurement result by a Doppler sensor provided facing the subject; a rate of change calculation means for calculating a rate of change of the value of the Doppler data at each of a plurality of consecutive time points; a time window change rate total calculation means for calculating, for each of a plurality of time windows each including a first predetermined number of consecutive time points, a total of absolute values ​​of the change rates at each of the first predetermined number of time points included in the time window as a time window change rate total corresponding to the time window; a motionless state determination means for determining that the subject is not performing a desired motion based on an average, a sum, or a variance of the time window change rate sums corresponding to each of the second predetermined number of consecutive time windows; A non-operating state determination system including:

2. The motionless state determination system according to claim 1, the change rate calculation means calculates a change rate of the value of the Doppler data at each of the plurality of time points for each of the plurality of Doppler sensors; The time window change rate total calculation means an individual time window change rate sum calculation means for calculating, for each of a plurality of time windows each including a first predetermined number of consecutive time points for each of the plurality of Doppler sensors, a sum of absolute values ​​of the change rates at each of the first predetermined number of time points included in the time window as an individual time window change rate sum corresponding to the time window; and a time window change rate total calculation means for calculating, for each of the plurality of time windows, a sum of the individual time window change rate totals corresponding to that time window of each of the plurality of Doppler sensors as a time window change rate total corresponding to that time window.

3. The motionless state determination system according to claim 1, the change rate calculation means calculates a change rate of the value of the Doppler data at each of the plurality of time points for each of the plurality of Doppler sensors; a time-point change rate total calculation means for calculating, for each of the plurality of time points, a sum of absolute values ​​of the change rates of the respective Doppler sensors as a time-point change rate total corresponding to the time point; the time window change rate total calculation means calculates, for each of a plurality of time windows each including a first predetermined number of consecutive time points, a sum of the time point change rate totals at each of the first predetermined number of time points included in the time window as a time window change rate total corresponding to the time window; Non-operating state determination system.

4. an acquisition means for repeatedly acquiring Doppler data indicating a measurement result by a Doppler sensor provided facing the subject; a rate of change calculation means for calculating a rate of change of the value of the Doppler data at each of a plurality of consecutive time points; a motionless state determination means for determining whether the subject is not performing a desired motion based on an average, a sum, or a variance of the absolute values ​​of the rate of change at each of the plurality of time points; A non-operating state determination system including:

5. The motionless state determination system according to claim 4, the change rate calculation means calculates a change rate of the value of the Doppler data at each of the plurality of time points for each of the plurality of Doppler sensors; a time-point change rate total calculation means for calculating, for each of the plurality of time points, a sum of absolute values ​​of the change rates of the respective plurality of Doppler sensors as a time-point change rate total corresponding to the time point; The motionless state determination means determines that the subject is not exhibiting an expected movement based on the average, sum, or variance of the total time-point change rates corresponding to each of the multiple time points.

6. an acquisition means for repeatedly acquiring Doppler data indicating a measurement result by a Doppler sensor provided facing the subject; a rate of change calculation means for calculating a rate of change of the value of the Doppler data at each of a plurality of consecutive time points; a motionless state determination means for determining whether the subject is not performing a desired motion based on the variance of the rate of change at each of the plurality of time points; A non-operating state determination system including:

7. 7. The motionless state determination system according to claim 6, the change rate calculation means calculates a change rate of the value of the Doppler data at each of the plurality of time points for each of the plurality of Doppler sensors; a variance calculation means for calculating a variance of a rate of change of the value of the Doppler data at each of the plurality of time points for each of the plurality of Doppler sensors; The motionless state determination means determines that the subject is not exhibiting an expected movement based on the average or sum of the variances of the change rates in each of the multiple Doppler sensors.

8. The motionless state determination system according to any one of claims 1 to 7, The motionless state determination means determines whether the subject is in an apnea state.

9. The motionless state determination system according to any one of claims 1 to 7, The motionless state determination means determines whether the subject has bradycardia arrhythmia.

10. A step in which a motionless state determination system repeatedly acquires Doppler data indicating a measurement result by a Doppler sensor provided facing the subject; a step of the motionless state determination system calculating a rate of change of the value of the Doppler data at each of a plurality of consecutive time points; a step in which the motionless state determination system calculates, for each of a plurality of time windows each including a first predetermined number of consecutive time points, a sum of absolute values ​​of the change rates at each of the first predetermined number of time points included in the time window as a time window change rate sum corresponding to the time window; a step of the motionless state determination system determining that the subject is not exhibiting a desired motion based on an average, a sum, or a variance of the time window change rate sums corresponding to each of the second predetermined number of consecutive time windows; A method for determining a motionless state, comprising:

11. A step in which a motionless state determination system repeatedly acquires Doppler data indicating a measurement result by a Doppler sensor provided facing the subject; a step of the motionless state determination system calculating a rate of change of the value of the Doppler data at each of a plurality of consecutive time points; The motionless state determination system determines that the subject is not performing a desired motion based on an average, a sum, or a variance of the absolute values ​​of the change rates at each of the multiple time points; A method for determining a motionless state, comprising:

12. A step in which a motionless state determination system repeatedly acquires Doppler data indicating a measurement result by a Doppler sensor provided facing the subject; a step of the motionless state determination system calculating a rate of change of the value of the Doppler data at each of a plurality of consecutive time points; a step of the motionless state determination system determining that the subject is not performing an expected motion based on a variance of the rate of change at each of the plurality of time points; A method for determining a motionless state, comprising:

13. Repeatedly acquiring Doppler data indicating a measurement result by a Doppler sensor provided facing the subject; calculating a rate of change of the value of the Doppler data at each of a plurality of consecutive time points; calculating, for each of a plurality of time windows each including a first predetermined number of consecutive time points, a sum of absolute values ​​of the change rates at each of the first predetermined number of time points included in the time window as a time window change rate sum corresponding to the time window; determining that the subject is not performing a desired movement based on an average, sum, or variance of the time window change rate sums corresponding to each of a second predetermined number of consecutive time windows; A program for causing a computer to execute the following.

14. Repeatedly acquiring Doppler data indicating a measurement result by a Doppler sensor provided facing the subject; calculating a rate of change of the value of the Doppler data at each of a plurality of consecutive time points; determining whether the subject is not performing an expected movement based on an average, a sum, or a variance of the absolute values ​​of the rate of change at each of the plurality of time points; A program for causing a computer to execute the following.

15. Repeatedly acquiring Doppler data indicating a measurement result by a Doppler sensor provided facing the subject; calculating a rate of change of the value of the Doppler data at each of a plurality of consecutive time points; determining whether the subject is not performing an expected movement based on a variance of the rate of change at each of the plurality of time points; A program for causing a computer to execute the following.

Images