Support surface movement control device, support surface movement control method, and support equipment

Abstract

A support surface movement control device (30) that controls movement of a support surface (520) that supports the body of a user (U) comprises a movement control unit (34) that controls the movement of the support surface. The support surface includes an upper body support part (521) that supports the upper body of the user on the support surface. The movement control unit executes lowering control that moves the upper body support part in a direction in which an inclination angle of the upper body support part is reduced. The movement control unit intermittently reduces, in the lowering control, the inclination angle of the upper body support part at an interval greater than or equal to a respiratory cycle of the user.

Description

Support surface movement control device, support surface movement control method, and support equipment

[0001] This disclosure relates to a support surface movement control device, a support surface movement control method, and a support device.

[0002] Various devices such as beds, sofas, chairs, and wheelchairs are used as support devices for the human body. Furthermore, one type of support device known is one in which the support surface for the human body is movable. For example, in reclining beds, reclining sofas, and reclining chairs, the portion of the support surface that supports the human upper body is pivotable relative to the horizontal plane.

[0003] Regarding support devices in which the support surface is configured to be movable, it has been proposed that the movement of the support surface be controlled by a control device such as a computer. Patent Document 1 describes a bed device that includes a back-raising control unit for controlling the backrest and a back-lowering control unit for controlling the backrest.

[0004] Patent No. 5665411 specification

[0005] In conventional devices, when the support surface is moved according to the control of the control device, the sleep of the user on the support surface may be disturbed.

[0006] This disclosure aims to provide a support surface movement control device, a support surface movement control method, and a support device that suppress disturbance to the sleep of a user on the support surface due to the movement of the support surface.

[0007] A support surface movement control device is provided that controls the movement of a support surface that supports the body of a user, comprising a movement control unit that controls the movement of the support surface, wherein the support surface has an upper body support portion that supports the upper body of the user on the support surface, the movement control unit performs a downward control that moves the upper body support portion in a direction that reduces the inclination angle of the upper body support portion, and in the downward control, the movement control unit intermittently reduces the inclination angle of the upper body support portion at intervals longer than the user's breathing cycle.

[0008] A support device is provided that comprises a support surface for supporting the user's body and a support surface movement control device according to the first embodiment.

[0009] A third aspect of the present disclosure provides a support surface movement control method for controlling the movement of a support surface that supports the body of a user, wherein the support surface has an upper body support portion that supports the upper body of the user on the support surface, and the movement control unit performs a downward control to move the upper body support portion in a direction that reduces the inclination angle of the upper body support portion, wherein the movement control unit intermittently reduces the inclination angle of the upper body support portion at intervals greater than or equal to the user's breathing cycle in the downward control method.

[0010] According to this disclosure, a support surface movement control device, a support surface movement control method, and a support device are provided that suppress disturbance to the sleep of a user on the support surface due to the movement of the support surface.

[0011] Figures 1(a) to 1(c) are side views of a bed controlled by a bed base movement control device. In Figure 1(a), the first, second, third, and fourth bed bases are in a horizontal position. In Figure 1(b), the first bed base is in the backrest position, and the second, third, and fourth bed bases are in a horizontal position. In Figure 1(c), the first bed base is in the backrest position, the second bed base is in a horizontal position, and the third and fourth bed bases are in the knee-raised position. Figure 2 is a plan view showing the arrangement of load detectors on the bed. Figure 3 is a block diagram showing the configuration of a bed base movement control system according to an embodiment of this disclosure. Figure 4 is a flowchart of the process for acquiring biological information. Figure 5(a) is an explanatory diagram showing the vibration of the center of gravity in accordance with the user's breathing. Figure 5(b) is an explanatory diagram for explaining the method of drawing the respiratory waveform. Figure 6 is a flowchart of sleep onset movement control. Figure 7 is an explanatory diagram for explaining the control contents of the bed base movement control unit.

[0012] <Embodiment> The floor plate movement control system 100 (Figure 3) of the embodiment of the present disclosure will be described with reference to Figures 1 to 7, using the case in which the floor plate movement control system 100 is used for a bed 500 (Figure 1, an example of a "support device").

[0013] [Bed 500] As shown in Figures 1 and 2, the bed 500 controlled by the floorboard movement control system 100 has a base portion 510, a floorboard 520 (an example of a "support surface") supported by the base portion 510, and a movement mechanism 530 for moving the floorboard 520. In the following description, the long side direction (direction of the Y axis in Figure 2) and the short side direction (direction of the X axis in Figure 2) of the bed 500 and floorboard 520 will be referred to as the longitudinal direction and width direction of the bed 500 and floorboard 520, respectively.

[0014] The base portion 510 has a rectangular frame 511 in plan view and four legs 512 provided at the four corners of the frame 511.

[0015] The bed base 520 has four bed bases, a first bed base 521, a second bed base 522, a third bed base 523, and a fourth bed base 524, arranged in order from the head side of the bed 500 (the positive side in the Y-axis direction in Figure 2) along the longitudinal direction of the bed 500. As a guideline, the first bed base 521, the second bed base 522, the third bed base 523, and the fourth bed base 524 support the upper body, buttocks, thighs, and lower legs of the user U (Figure 2) on the bed base 520, respectively. The first bed base 521 is an example of an "upper body support section," and the third bed base 523 and the fourth bed base 524 are examples of "leg support sections."

[0016] The first bed plate 521 is located near the second bed plate 522 and is pivotable around an axis AX1 extending in the width direction of the bed 500. The second bed plate 522 is fixed to the base portion 510. The third bed plate 523 is located near the second bed plate 522 and is pivotable around an axis AX3 extending in the width direction of the bed 500. The fourth bed plate 524 is connected to the third bed plate 523, is located at the connection point with the third bed plate 523, and is pivotable around an axis AX4 extending in the width direction of the bed 500.

[0017] The moving mechanism 530 includes a first moving mechanism 531 for moving the first floor plate 521 and a second moving mechanism 532 for moving the third floor plate 523 and the fourth floor plate 524. In this embodiment, the first moving mechanism 531 and the second moving mechanism 532 are electric cylinders. However, the first moving mechanism 531 and the second moving mechanism 532 may be any actuator.

[0018] The operation of the first moving mechanism 531 causes the first floor plate 521 to pivot around axis AX1, displacing between a horizontal position where the top surface of the first floor plate 521 coincides with the horizontal plane (Figure 1(a)) and a maximum back-raised position where the top surface of the first floor plate 521 is inclined with respect to the horizontal plane (Figures 1(b) and 1(c)). The inclination angle α of the first floor plate 521 at the maximum back-raised position (i.e., the maximum value that the inclination angle α can take) is arbitrary, but as an example, it can be about 30 to 45 [°]. At the horizontal position, the top surface of the first floor plate 521 and the top surface of the second floor plate 522 are flush. That is, the inclination angle α is 0 [°]. In this disclosure and the present invention, "angle of inclination" means the angle (acute angle) made with respect to the horizontal plane.

[0019] The operation of the second movement mechanism 532 causes the third floor plate 523 to pivot around axis AX3. At this time, the fourth floor plate 524 pivots around axis AX4, moving vertically while maintaining a state in which the top surface of the fourth floor plate 524 coincides with the horizontal plane. As a result, the third floor plate 523 and the fourth floor plate 524 are displaced between a horizontal position in which the top surfaces of the third floor plate 523 and the fourth floor plate 524 coincide with the horizontal plane (Figures 1(a) and 1(b)), and the maximum knee-raising position in which the top surface of the third floor plate 523 is inclined with respect to the horizontal plane, the top surface of the fourth floor plate 524 coincides with the horizontal plane, and is located above the top surface of the second floor plate 522 (Figure 1(c)). In the horizontal position, the top surfaces of the third floor plate 523 and the fourth floor plate 524 are flush with the top surface of the second floor plate 522. The inclination angle β of the third floor plate 523 at the maximum knee-raising position (i.e., the maximum value that the inclination angle β can take) can be approximately 25 to 40°. In the horizontal position, the top surface of the third floor plate 523 and the top surface of the second floor plate 522 are flush. That is, the inclination angle β is 0°.

[0020] [Configuration of the floorboard movement control system 100] As shown in Figure 3, the floorboard movement control system 100 of this embodiment mainly comprises a load detection unit 10, a control unit (an example of a "support surface movement control device") 30, and a storage unit 40. The load detection unit 10 and the control unit 30 are connected via an A / D conversion unit 20. A display unit 50, a notification unit 60, and an input unit 70 are further connected to the control unit 30. The first movement mechanism 531 and the second movement mechanism 532 of the bed 500 are connected to the control unit 30.

[0021] The load detection unit 10 includes four load detectors 11, 12, 13, and 14. Each of the load detectors 11, 12, 13, and 14 is a load detector that detects a load using, for example, a beam-type load cell. Each of the load detectors 11, 12, 13, and 14 is connected to an A / D conversion unit 20 via wiring or wireless communication.

[0022] As shown in FIG. 2, the four load detectors 11 to 14 of the load detection unit 10 are respectively arranged below casters C1, C2, C3, and C4 attached to the lower ends of the four legs 512 of a bed 500.

[0023] The A / D conversion unit 20 includes an A / D converter that converts an analog signal from the load detection unit 10 into a digital signal, and is connected to the load detection unit 10 and a control unit 30 via wiring or wireless communication, respectively.

[0024] The control unit 30 is a dedicated or general-purpose computer, and has a center-of-gravity position calculation unit 31, a respiration information acquisition unit 32, a sleep determination unit 33, and a floor plate movement control unit 34 (an example of a "movement control unit") constructed therein. The respiration information acquisition unit 32 includes a respiration waveform acquisition unit 321, a respiration state determination unit 322, and a respiration cycle acquisition unit 323.

[0025] The storage unit 40 is a storage device that stores data used in the floor plate movement control system 100, and for example, a hard disk (magnetic disk) can be used. The display unit 50 is a monitor such as a liquid crystal monitor that displays information output from the control unit 30. The notification unit 60 includes a device that auditorily performs a predetermined notification based on information from the control unit 30, for example, a speaker. The input unit 70 is an interface for performing predetermined input to the control unit 30, and may be a keyboard and a mouse.

[0026] [Operation of Floor Plate Movement Control System 100] The floor plate movement control system 100 constantly acquires biological information of a user U on a bed 500. The floor plate movement control system 100 moves a floor plate 520 through control based on the acquired biological information.

[0027] [Acquisition of biological information] Acquisition of biological information is mainly executed by the respiratory information acquisition unit 32 and the sleep determination unit 33 of the control unit 30. The respiratory information acquisition unit 32 and the sleep determination unit 33 of the present embodiment continuously acquire the biological information of the user U on the bed 500 at a predetermined cycle. As shown in the flow chart of FIG. 4, the acquisition of biological information executed by the respiratory information acquisition unit 32 and the sleep determination unit 33 mainly includes a load detection step S11, a centroid position calculation step S12, a respiratory waveform acquisition step S13, a respiratory state determination step S14, a respiratory cycle acquisition step S15, and a sleep determination step S16.

[0028] In the load detection step S11, the load of the user U on the floor board 520 (the bed 500) is detected using the load detectors 11, 12, 13, and 14. The load of the user U on the floor board 520 is分散 applied to the load detectors 11 to 14 arranged under the four legs 512 of the bed 500, and is detected in a分散 manner by these detectors.

[0029] Each of the load detectors 11 to 14 detects a load (load change) and outputs it as an analog signal to the A / D conversion unit 20. The A / D conversion unit 20 converts the analog signal into a digital signal with a sampling cycle of, for example, 5 milliseconds, and outputs the digital signal (hereinafter referred to as "load signal") to the control unit 30. Hereinafter, the load signals obtained by digitally converting the analog signals output from the load detectors 11, 12, 13, and 14 in the A / D conversion unit 20 are respectively referred to as load signals １ , s ２ , s ３ , s ４ .

[0030] In the centroid position calculation step S12, the centroid position calculation unit 31 calculates the position of the centroid G of the user U based on the load signals s １ , s ２ , s ３ , s ４ .

[0031] For the position of the centroid G, let the position of the centroid G in the XY coordinates shown in FIG. 2 be (x, y), and let the coordinates of the load detectors 11, 12, 13, and 14 be respectively (X １ , Y １ ), (X ２ , Y ２ ), (X ３ , Y３ ), (X ４ , Y ４ ) and load signal s １ s ２ s ３ s ４ The partial load of user U, as shown by W, is １ , W ２ , W ３ , W ４ Therefore, it can be calculated using the following equations (Equation 1) and (Equation 2).

[0032]

[0033] In the respiratory waveform acquisition process S13, the respiratory waveform acquisition unit 321 acquires the load signal s １ ~s ４ Based on this, the respiratory waveform of user U is continuously acquired.

[0034] Human respiration occurs by moving the rib cage and diaphragm to expand and contract the lungs. During inhalation, when the lungs expand, the diaphragm moves downward, and the internal organs also move downward. Conversely, during exhalation, when the lungs contract, the diaphragm moves upward, and the internal organs also move upward. Along with this movement of the internal organs, the center of gravity G shifts slightly, and the direction of this movement is roughly in line with the direction of spinal extension (axis direction).

[0035] A "respiratory waveform" is a waveform that shows, for example, the vibration of a user's center of gravity in the direction of the user's body axis in response to their breathing, unfolded over time. One cycle of the respiratory waveform corresponds to one breath (exhalation and inhalation) by the user. The amplitude of the respiratory waveform is affected by the user's physique and breathing depth. Specifically, for example, the amplitude will be larger if the user is large or takes deep breaths, and smaller if the user is small or takes shallow breaths.

[0036] Specifically, the respiratory waveform acquisition unit 321 draws the respiratory waveform as follows.

[0037] As shown in Figure 5(a), the position of the user U's center of gravity G, calculated by the center of gravity position calculation unit 31, vibrates in the direction of the user U's body axis UA in accordance with the user U's breathing.

[0038] The respiratory waveform acquisition unit 321 plots the respiratory waveform BW (Figure 5(b)) on the vertical axis, with the direction of the body axis UA as the vertical axis and the time axis as the horizontal axis, by plotting the distance between the position of the center of gravity G projected onto the body axis UA at each time point and the center of vibration of the vibration corresponding to the respiration of the center of gravity G on the vertical axis.

[0039] Furthermore, the respiratory waveform acquisition unit 321 does not necessarily need to actually draw the respiratory waveform; it may simply acquire data that represents the respiratory waveform. Also, instead of the respiratory waveform BW based on the movement of the center of gravity G, the respiratory waveform acquisition unit 321 uses a load signal s as the waveform representing the user U's breathing. １ ~s ４ Alternatively, a signal in a frequency band corresponding to the user U's breathing frequency (for example, approximately 0.2 Hz to 0.33 Hz) may be separated from any one of the signals by filtering. In addition, the breathing waveform acquisition unit 321 may acquire any signal that shows vibrations corresponding to the user U's breathing as a waveform representing the user U's breathing.

[0040] In the respiratory state determination step S14, the respiratory state determination unit 322 determines whether the user U's respiratory state is expiratory or inspiratory based on the respiratory waveform BW. During the period when user U is exhaling, user U's respiratory state is expiratory. During the period when user U is inhaling, user U's respiratory state is inspiratory.

[0041] Specifically, the respiratory state determination unit 322 determines the respiratory state of user U based on the following principle, for example.

[0042] In the respiratory waveform BW shown in Figure 5(b), the positive peak pp appears when the user U's center of gravity G is located furthest towards the head. That is, when the positive peak pp appears in the respiratory waveform BW, the user U is in a state where exhalation has finished. On the other hand, the negative peak np appears when the user U's center of gravity G is located furthest towards the legs. That is, when the negative peak np appears in the respiratory waveform BW, the user U is in a state where inspiration has finished. Therefore, the respiratory state determination unit 322 can determine that the user U is in an inspiratory state during the period when the respiratory waveform BW moves from the positive peak pp to the negative peak np, i.e., the falling phase of the respiratory waveform BW, and that the user U is in an expiratory state during the period when the respiratory waveform BW moves from the negative peak np to the positive peak pp, i.e., the rising phase of the respiratory waveform BW.

[0043] Specifically, the respiratory state determination unit 322 performs the determination by, for example, the following steps. First, the respiratory state determination unit 322 continuously detects peaks in the respiratory waveform BW continuously acquired by the respiratory waveform acquisition unit 321, and sequentially identifies positive peaks pp and negative peaks np. Then, it determines that the user U's respiratory state is inspiratory during the period after a positive peak pp is identified on the respiratory waveform BW. Subsequently, it determines that the user U's respiratory state is expiratory during the period after a negative peak np is identified on the respiratory waveform BW. In this way, the respiratory state determination unit 322 switches the determination result based on the positive peaks pp and negative peaks np identified on the respiratory waveform BW.

[0044] Furthermore, the respiratory state determination unit 322 uses the load signal s instead of the respiratory waveform BW. １ ~s ４ Even when using a respiratory waveform obtained by filtering out a signal in the frequency band corresponding to the user U's breathing frequency from any one of the above, the user U's respiratory state can be determined by the same process.

[0045] In the respiratory cycle acquisition process S15, the respiratory cycle acquisition unit 323 acquires the user U's respiratory cycle RP based on the respiratory waveform BW. Specifically, the respiratory cycle RP is equal to, for example, the time from the start of exhalation to the start of the next exhalation, or the time from the start of inhalation to the start of the next inhalation.

[0046] Specifically, the respiratory cycle acquisition unit 323 calculates, for example, the interval between two adjacent positive peaks pp on the respiratory waveform BW and acquires the calculated value as the respiratory cycle RP. Alternatively, for M consecutive positive peaks pp on the respiratory waveform BW, the respiratory cycle acquisition unit 323 may acquire the respiratory cycle RP using the following formula, where D is the interval between the first and last peaks among the M positive peaks pp: (Formula 3) RP = D / (M - 1)

[0047] Furthermore, even when the respiratory cycle acquisition unit 323 uses a negative peak np instead of a positive peak pp, it can acquire the user U's respiratory cycle RP by the same process as described above. In addition, the respiratory cycle acquisition unit 323 can use a load signal s instead of the respiratory waveform BW. １ ~s ４ Even when using a respiratory waveform obtained by filtering out a signal in the frequency band corresponding to the user U's breathing frequency from any one of the above, the user U's respiratory cycle RP can be obtained by the same process.

[0048] In the sleep determination process S16, the sleep determination unit 33 determines whether the user U is asleep or awake.

[0049] The sleep determination unit 33 receives the load signal s according to (Equation 4) below. １ ~s ４ Standard deviation σ １ ~σ ４ The Activity Index (ACI), which is the time integral of the simple average, is calculated.

[0050] The integration time is 20 seconds here, but it is not limited to this. Standard deviation σ １ ~σ ４ Since it increases in response to the user U's body movements, the activity index ACI will be larger if the user U exhibits body movements that cause larger load changes over a longer period of time. In other words, the activity index ACI is a parameter that reflects both the magnitude of the body movement and the duration of the body movement.

[0051] The sleep determination unit 33 calculates the standard deviation σ at each sampling time in the past 20 seconds every 20 seconds. １ ~σ４ Using the value, a new activity index ACI is calculated. Then, the calculated activity index ACI and the threshold TH ＡＣＩ Based on a comparison with the above, it is determined whether user U is in a sleep state or a wakeful state. Specifically, for example, if the activity index ACI is at threshold TH ＡＣＩ If the value is smaller than this, it is determined that user U is in a sleep state. The sleep determination unit 333 may determine that user U is in a sleep state by any other method.

[0052] [Control of Bed Board Movement] In this embodiment, the control of the movement of the bed board 520 includes sleep-onset movement control. In sleep-onset movement control, the bed board movement control unit 34, as an example, moves the first bed board 521, which is in the maximum back-raised position, to a horizontal position, and moves the third bed board 523 and fourth bed board 524, which are in the maximum knee-raised position, to a horizontal position. This changes the shape of the bed board 520 from a shape suitable for the user U to fall asleep to a shape suitable for the user U to continue sleeping. In this embodiment, when the first bed board 521 is in the maximum back-raised position and the third bed board 523 and fourth bed board 524 are in the maximum knee-raised position, the inclination angle α is greater than the inclination angle β.

[0053] The sleep onset movement control will be explained using the flowchart in Figure 6. In Figure 6, step S21 is the start decision step, and step S22 is the descent control step (an example of "descent control").

[0054] In step S21 (start determination step), the floorboard movement control unit 34 determines whether or not the user U is in a sleep state. The floorboard movement control unit 34 refers to the latest determination result from the sleep determination step S16. If the floorboard movement control unit 34 determines that the user U is not in a sleep state (step S21: NO), it executes step S21 again.

[0055] If the floorboard movement control unit 34 determines that the user U is asleep (step S21: YES), it starts the lowering control process. That is, the floorboard movement control unit 34 activates the first movement mechanism 531 and the second movement mechanism 532 to move the first floorboard 521, the third floorboard 523 and the fourth floorboard 524 toward the horizontal position (step S22).

[0056] In step S22, the floor plate movement control unit 34 reduces the inclination angle α of the first floor plate 521 and the inclination angle β of the third floor plate 523 to 0° at a speed V [° / sec]. That is, it moves the first floor plate 521, the third floor plate 523 and the fourth floor plate 524 to a horizontal position.

[0057] In step S22, the floorboard movement control unit 34 intermittently reduces the inclination angle α of the first floorboard 521 at intervals equal to or greater than the user U's respiratory cycle RP, based on the determination result of the respiratory state determination unit 322 in the respiratory state determination step S14 and the respiratory cycle acquisition unit 323 acquired by the user U in the respiratory cycle acquisition step S15. In this disclosure and the present invention, the "interval" of the intermittent reduction of the inclination angle means the length of the period from the start of one reduction (start of movement) to the start of the next reduction (start of movement).

[0058] Several specific examples of the control performed by the floor plate movement control unit 34 in step S22 will be explained with reference to the timing charts TC1 to TC4 in Figure 7. In the timing charts TC1 to TC4 in Figure 7, the gray (or black) period indicates that the first floor plate 521 is moving toward the horizontal position, and the white period indicates that the first floor plate 521 is stopped. Also in Figure 7, the exhalation period EP indicates the period when the user U is in an exhaling state, and the inspiratory period IP indicates the period when the user U is in an inhaling state.

[0059] Specifically, for example, the bed base movement control unit 34 intermittently moves the first bed base 521 at intervals that are twice the respiratory cycle RP of the user U acquired by the respiratory cycle acquisition unit 323 during the expiratory period EP when the user U is in an expiratory state, thereby intermittently decreasing the inclination angle α of the first bed base 521 (Figure 7, timing chart TC1).

[0060] In this case, for example, the floorboard movement control unit 34 starts moving the first floorboard 521 at the timing when the user U's breathing state switches from an inhaling state to an exhaling state, based on the determination result of the breathing state determination unit 322 in the breathing state determination step S14. Then, the floorboard movement control unit 34 continues to drive the first movement mechanism 531 for a period P to move the first floorboard 521 toward a horizontal position, and then stops the first movement mechanism 531 to end the movement of the first floorboard 521. The floorboard movement control unit 34 completes the movement of the first floorboard 521 within the exhalation period EP.

[0061] The period P can be any length that is less than or equal to the length of the expiratory period EP. For example, the period P may be approximately 0.1 [s] to 1.0 [s]. Human respiration is typically 12 to 20 breaths per minute. Therefore, the respiratory cycle RP is usually approximately 3 [s] to 5 [s], and the lengths of the expiratory period EP and the inspiratory period IP are usually approximately 1.5 [s] to 2.5 [s], respectively.

[0062] The floorboard movement control unit 34 then initiates the movement of the first floorboard 521 and moves it toward a horizontal position over a period P at intervals that are twice the respiratory cycle RP of the user U, which is acquired by the respiratory cycle acquisition unit 323 in the respiratory cycle acquisition process S15. As an example, at the start of process S22, the floorboard movement control unit 34 acquires the latest value of the user U's respiratory cycle RP from the respiratory cycle acquisition unit 323. It then determines that twice this latest value is the length of the interval for intermittent movement. The floorboard movement control unit 34 uses the determined interval length until process S22 is completed. That is, from the start to the end of process S22, the floorboard movement control unit 34 periodically performs the intermittent movement of the first floorboard 521 at regular intervals.

[0063] As another specific example, the bed base movement control unit 34 intermittently moves the first bed base 521 at intervals equal to the respiratory cycle RP of the user U acquired by the respiratory cycle acquisition unit 323 during the expiratory period EP when the user U is in an expiratory state, thereby intermittently decreasing the inclination angle α of the first bed base 521 (Figure 7, timing chart TC2).

[0064] In this case, for example, the floorboard movement control unit 34 starts moving the first floorboard 521 at the timing when the user U's breathing state switches from an inhaling state to an exhaling state, based on the determination result of the breathing state determination unit 322 in the breathing state determination step S14. Then, the floorboard movement control unit 34 continues to drive the first movement mechanism 531 for a period P to move the first floorboard 521 toward a horizontal position, and then stops the first movement mechanism 531 to end the movement of the first floorboard 521.

[0065] Subsequently, the floorboard movement control unit 34 initiates the movement of the first floorboard 521 and moves it toward a horizontal position over a period P at intervals equal to the respiratory cycle RP of the user U acquired by the respiratory cycle acquisition unit 323 in the respiratory cycle acquisition process S15.

[0066] In addition, the floor plate movement control unit 34 may set the interval of intermittent movement of the first floor plate 521 to any natural number multiple of the user U's respiratory cycle RP acquired by the respiratory cycle acquisition unit 323. In this disclosure and the present invention, "an interval that is a natural number multiple of the user's respiratory cycle" includes an interval that is 1 times the user's respiratory cycle, i.e., an interval that is the same as the user's respiratory cycle. In this disclosure and the present invention, "natural number" does not include zero.

[0067] In this embodiment, the floorboard movement control unit 34 moves the third floorboard 523 and the fourth floorboard 524 simultaneously with the movement of the first floorboard 521. If the first floorboard 521 reaches the horizontal position before the third floorboard 523 and the fourth floorboard 524, the floorboard movement control unit 34 may move the third floorboard 523 and the fourth floorboard 524 in any manner. The floorboard movement control unit 34 terminates floorboard movement control when the first floorboard 521 and the third floorboard 523 and the fourth floorboard 524 have reached the horizontal position.

[0068] The advantageous effects of the floor plate movement control system 100 of this embodiment are summarized below.

[0069] In the lowering control process, the floorboard movement control unit 34 intermittently reduces the inclination angle α of the first floorboard 521 at intervals greater than or equal to the user U's respiratory cycle RP. Since the body of user U, who is in a sleeping state, moves in rhythm corresponding to user U's breathing, if the interval of intermittent movement of the first floorboard 521 is longer than or equal to the user U's respiratory cycle RP (i.e., equal to or longer than the respiratory cycle RP), user U will be less likely to feel the movement of the first floorboard 521. Therefore, disruption of user U's sleep due to the movement of the first floorboard 521 is suppressed.

[0070] The bed base movement control unit 34 reduces the inclination angle α of the first bed base 521 at intervals that are natural multiples of the user U's respiratory cycle RP during the lowering control. By making the interval of the intermittent movement of the first bed base 521 a natural multiple of the user U's respiratory cycle RP, the user U becomes less sensitive to the movement of the first bed base 521, and the disturbance of the user U's sleep caused by the movement of the first bed base 521 can be suppressed more effectively.

[0071] In the lowering control, the bed base movement control unit 34 determines the length of the interval between intermittent movements of the first bed base 521 based on the respiratory cycle RP of the user U acquired by the respiratory cycle acquisition unit 323. This allows for a more appropriate determination of the interval length based on the user U's current state, thereby better suppressing disturbances to the user U's sleep.

[0072] In lowering control, the bed base movement control unit 34 reduces the inclination angle α of the first bed base 521 during the expiratory period EP in which the user U is exhaling, based on the determination result of the respiratory state determination unit 322. The expiratory period EP in which the user U is exhaling is the period in which the user U's lungs contract, and the user U's center of gravity moves from the user U's ventral side to the user U's posterior side. By reducing the inclination angle α of the first bed base 521 in a manner that is similar to the movement of the user U from the user U's ventral side to the user U's posterior side during this period, the user U becomes less sensitive to the movement of the first bed base 521, and the disturbance of the user U's sleep due to the movement of the first bed base 521 can be suppressed more effectively.

[0073] <Modification> In the above embodiment, the following modified form can also be used.

[0074] In the above embodiment, the bed base movement control unit 34 periodically performs intermittent movement of the first bed base 521 at regular intervals from the start to the end of process S22. However, it is not limited to this. The bed base movement control unit 34 may update the interval of intermittent movement of the first bed base 521 based on the respiratory cycle RP value of the user U acquired by the respiratory cycle acquisition unit 323 during the execution of process S22. Specifically, for example, the bed base movement control unit 34 determines the interval of intermittent movement of the first bed base 521 based on the respiratory cycle RP of the user U acquired by the respiratory cycle acquisition unit 323 each time a predetermined period has elapsed. Then, until the predetermined period has elapsed again and the interval is determined again, the intermittent movement of the first bed base 521 is performed at the determined interval.

[0075] In the above embodiment, the bed base movement control unit 34 moves the first bed base 521 during the expiratory period EP, when the user U is in an expiratory state, but is not limited to this. The bed base movement control unit 34 can intermittently move the first bed base 521 during the inspiratory period IP, when the user U is in an inspiratory state, at intervals that are any natural number multiples of the respiratory cycle RP of the user U acquired by the respiratory cycle acquisition unit 323, thereby intermittently decreasing the inclination angle α of the first bed base 521.

[0076] Specifically, for example, as shown in the timing chart TC3 of Figure 7, the bed base movement control unit 34 starts moving the first bed base 521 at the timing when the user U's breathing state switches from exhalation to inhalation, based on the determination result of the breathing state determination unit 322 in the breathing state determination step S14. Then, the bed base movement control unit 34 continues to drive the first movement mechanism 531 for a period P to move the first bed base 521 toward the horizontal position, and then stops the first movement mechanism 531 to end the movement of the first bed base 521. The bed base movement control unit 34 ends the movement of the first bed base 521 within the inhalation period IP.

[0077] Subsequently, the floorboard movement control unit 34 initiates the movement of the first floorboard 521 and moves it toward a horizontal position over a period P at intervals that are twice the respiratory cycle RP of the user U acquired by the respiratory cycle acquisition unit 323 in the respiratory cycle acquisition process S15.

[0078] In the above embodiment, the bed base movement control unit 34 intermittently moves the first bed base 521 based on both the determination result of the respiratory state determination unit 322 and the respiratory cycle RP of the user U acquired by the respiratory cycle acquisition unit 323. However, it is not limited to this.

[0079] The bed base movement control unit 34 may intermittently move the first bed base 521 without using the respiratory cycle RP of the user U acquired by the respiratory cycle acquisition unit 323.

[0080] Specifically, for example, the bed base movement control unit 34, based on the determination result of the respiratory state determination unit 322, reduces the inclination angle α of the first bed base 521 for a period P each time the respiratory state determination unit 322 determines that the determination result has switched to an "expiratory state" twice. In this configuration as well, the first bed base 521 moves intermittently at the timings shown in the timing chart TC1 of Figure 7. Alternatively, the bed base movement control unit 34 reduces the inclination angle α of the first bed base 521 for a period P each time the respiratory state determination unit 322 determines that the determination result has switched to an "expiratory state". In this configuration as well, the first bed base 521 moves intermittently at the timings shown in the timing chart TC2 of Figure 7.

[0081] The bed base movement control unit 34 may intermittently move the first bed base 521 without using the determination result of the respiratory state determination unit 322.

[0082] Specifically, for example, the bed base movement control unit 34 reduces the inclination angle α of the first bed base 521 for a period P when the respiratory cycle acquisition unit 323 identifies a negative peak np, and thereafter reduces the inclination angle α over the period P at intervals that are twice the respiratory cycle RP of the user U acquired by the respiratory cycle acquisition unit 323. In this configuration as well, the first bed base 521 moves intermittently at the timings shown in the timing chart TC1 of Figure 7.

[0083] In addition, the floor plate movement control unit 34 can intermittently reduce the inclination angle α of the first floor plate 521 at any interval greater than or equal to the user U's respiratory cycle RP.

[0084] The interval at which the floorboard movement control unit 34 moves the inclination angle α of the first floorboard 521 does not have to be constant. The floorboard movement control unit 34 may reduce the inclination angle α of the first floorboard 521 irregularly. Specifically, for example, based on the determination result of the respiratory state determination unit 322, the floorboard movement control unit 34 may reduce the inclination angle α of the first floorboard 521 over a period P at any timing within the expiratory period EP when the user U's respiratory state is expiratory (Figure 7, timing chart TC4). In this case, the length of the interval between the start of one movement and the start of the next movement is greater than or equal to the user U's respiratory cycle RP, but it is not the same for all of them.

[0085] The bed base movement control unit 34 may move the first bed base 521 based on the user U's respiratory cycle RP, which has been acquired in advance, rather than the user U's respiratory cycle RP acquired by the respiratory cycle acquisition unit 323. The user U's respiratory cycle RP, which has been acquired in advance, may be stored in the storage unit 40, for example, or may be input via the input unit 70.

[0086] Specifically, for example, user U inputs the user U's respiratory cycle RP (e.g., the average value of past measurements, the latest measurement, etc.) and an arbitrary natural number N via the input unit 70, based on past measurements. In step S22 of the bed base movement control process, the bed base movement control unit 34 intermittently reduces the inclination angle α of the first bed base 521 at intervals of N times the input respiratory cycle RP. The smaller the natural number N, the shorter the time it takes for the first bed base 521 to move to the horizontal position. On the other hand, the larger the natural number N, the less frequently the first bed base 521 moves, and the better the disruption of user U's sleep due to the movement of the first bed base 521 can be suppressed.

[0087] In the above embodiment, the floor plate movement control unit 34 moves the third floor plate 523 and the fourth floor plate 524 simultaneously with the movement of the first floor plate 521, but is not limited to this. The floor plate movement control unit 34 can move the third floor plate 523 and the fourth floor plate 524 in any manner.

[0088] In the above embodiments and their variations, the interval of intermittent movement of the first bed base 521 is equal to or greater than the user U's respiratory cycle RP for the entire duration of step S22, that is, the entire duration of the movement of the first bed base 521 from the maximum back-raised position to the horizontal position. However, it is not limited to this. The bed base movement control unit 34 may only set the interval of intermittent movement of the first bed base 521 to be equal to or greater than the user U's respiratory cycle RP for a portion of the duration of step S22. In this case as well, disturbance to the user U's sleep due to the movement of the first bed base 521 can be suppressed during that period. In the present invention, the phrase "intermittently reduce the inclination angle of the upper body support at intervals equal to or greater than the user's respiratory cycle" means reducing the inclination angle of the upper body support at least n times at intervals equal to or greater than the user's respiratory cycle. n may be any natural number greater than or equal to 2. Specifically, for example, n may be 2, 3, 5, or 10.

[0089] In the sleep-inducing movement control performed by the floorboard movement control system 100 of the above embodiment, the floorboard movement control unit 34 determines whether or not the user U is in a sleep state in step S21 (start determination step), but is not limited to this. In step S21, the floorboard movement control unit 34 may determine whether or not the current time has reached the set time, and if it determines that the current time has reached the set time, it may execute step S22.

[0090] In the floorboard movement control system 100 of the above embodiment, the floorboard movement control unit 34 automatically starts the lowering control process of the floorboard 520 based on the determination result of step S21. In this specification and the present invention, "the control unit automatically starts the lowering control" means that the control unit autonomously starts the lowering control based on condition determination, etc. The control unit starting the lowering control of the floorboard based on a determination of whether or not a preset condition has been met (for example, a determination of whether or not a set time has been reached, a determination of whether or not the user's physical information and / or biometric information meets predetermined conditions) is included in "the control unit automatically starts the lowering control". On the other hand, the control unit starting the movement of the floorboard in response to an artificial start instruction from the user, etc. (for example, a start instruction entered via key input, voice input, touch panel input, etc.) is not included in "the control unit automatically starts the lowering control". Note that the floorboard movement control unit 34 is not limited to the mode in which it automatically starts the lowering control process of the floorboard 520.

[0091] In the floorboard movement control system 100 of the above embodiment, any biosignal acquisition unit that acquires the user U's biosignals (signals that fluctuate in accordance with the user U's biological activity) can be used instead of the load detection unit 10. Specifically, for example, a plurality of pressure sensors arranged in a matrix under the sheet can be used to acquire the fluctuations in the pressure applied by the user U to the floorboard 520 as biosignals. In this embodiment, the position of the user's center of gravity, the presence or absence of body movement, the user's breathing state (exhalation state, inhalation state), breathing cycle, etc., can be determined based on the output of the plurality of pressure sensors.

[0092] The floor plate movement control system 100 of the above embodiment does not necessarily need to include all of the load detectors 11 to 14; it may include only one of them. For example, if there are three load detectors, the position of the user U's center of gravity on the top surface of the floor plate 520 can be detected as long as they are not arranged in a straight line. Also, the load detectors do not necessarily need to be placed at the four corners of the bed; they can be placed at any position so as to be able to detect the load of the subject on the bed and its fluctuations. Furthermore, the load detectors 11 to 14 are not limited to load sensors using beam-type load cells; for example, force sensors can also be used.

[0093] In the above embodiment, the use of the floorboard movement control system 100 on a bed 500 was described as an example, but the use of the floorboard movement control system 100 is not limited to a bed 500. The floorboard movement control system 100 can be used as a support surface movement control system to control the movement of the support surface of any support device in which the support surface that supports the human body is configured to be movable, such as a bed, sofa, chair, or wheelchair. In this case, the support surface movement control system may be capable of performing downward control to move, for example, a backrest (an example of an "upper body support section"), a leg rest (an example of a "leg support section"), etc., in a direction that reduces the inclination angle.

[0094] As long as the features of the present invention are maintained, the present invention is not limited to the embodiments described above, and other forms conceivable within the scope of the technical idea of ​​the present invention are also included within the scope of the present invention.

[0095] 11, 12, 13, 14 Load detector; 30 Control unit; 31 Center of gravity position calculation unit; 32 Respiratory information acquisition unit; 321 Respiratory waveform acquisition unit; 322 Respiratory state determination unit; 323 Respiratory cycle acquisition unit; 33 Sleep determination unit; 34 Bed base movement control unit; 500 Bed; 520 Bed base

Claims

1. A support surface movement control device for controlling the movement of a support surface that supports the body of a user, comprising a movement control unit for controlling the movement of the support surface, wherein the support surface has an upper body support portion that supports the upper body of the user on the support surface, the movement control unit performs a downward control to move the upper body support portion in a direction that reduces the inclination angle of the upper body support portion, and the movement control unit intermittently reduces the inclination angle of the upper body support portion at intervals longer than the user's breathing cycle during the downward control.

2. The support surface movement control device according to claim 1, wherein the interval is a natural number multiple of the user's respiratory cycle.

3. The support surface movement control device according to claim 1 or 2, further comprising a respiratory cycle acquisition unit that acquires the user's respiratory cycle, wherein the movement control unit determines the interval based on the user's respiratory cycle acquired by the respiratory cycle acquisition unit.

4. The support surface movement control device according to any one of claims 1 to 3, wherein the movement control unit reduces the inclination angle of the upper body support during the period in which the user is exhaling during the downward control.

5. The support surface movement control device according to any one of claims 1 to 4, wherein the movement control unit automatically starts and executes the lowering control.

6. The support surface movement control device according to claim 5, further comprising a sleep determination unit that determines whether the user on the support surface is in a sleep state, wherein the movement control unit starts the downward control based on the sleep determination unit's determination that the user is in a sleep state.

7. A support device comprising a support surface for supporting the user's body and a support surface movement control device according to any one of claims 1 to 6.

8. A support surface movement control method for controlling the movement of a support surface that supports the body of a user, wherein the support surface has an upper body support portion that supports the upper body of the user on the support surface, and the movement control unit performs a downward control to move the upper body support portion in a direction that reduces the inclination angle of the upper body support portion, wherein the movement control unit intermittently reduces the inclination angle of the upper body support portion at intervals longer than the user's breathing cycle during the downward control.

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