Fall risk determination device

Abstract

To provide a fall risk determination device capable of easily determining a risk of a user falling.SOLUTION: In a fall risk determination system 100, a fall risk determination device 10 connectable to a head-mounted display 40 for generating augmented reality and being worn by a user includes: a virtual object generation control unit 12 for generating and moving a virtual object; and a fall risk determination unit 14 for determining a fall risk of the user. The head-mounted display 40 includes: a movement amount acquisition unit 42 for acquiring the movement amount of the user; and a position information acquisition unit 44 for acquiring position information of the virtual object 70. The fall risk is determined on the basis of the difference between the movement amount corresponding to an extracted emission time and the movement amount corresponding to an extracted passage time.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a head-mounted display that generates augmented reality and is worn by a user, and a fall risk assessment device that can be connected to the head-mounted display. [Background technology]

[0002] Head-mounted displays (HMDs) are used for a variety of purposes, including medical diagnosis, treatment, and rehabilitation. The system shown in Patent Document 1 uses augmented reality to display specific images, enabling rehabilitation for higher brain dysfunction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7036327 Summary of the Invention [Problem to be solved by the invention]

[0004] However, although the above-mentioned system allows doctors and practitioners to grasp the rehabilitation status of a patient, it does not take into consideration the examination of the progress of the patient's condition.

[0005] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a fall risk assessment device that can easily assess the risk of a user falling. [Means for solving the problem]

[0006] A fall risk assessment device according to the present invention is a fall risk assessment device connectable to a head-mounted display that generates augmented reality and is worn by a user, the fall risk assessment device having a virtual object generation control unit that generates and moves a virtual object, and a fall risk assessment unit that assesses the user's fall risk, the head-mounted display having a movement amount acquisition unit that acquires the amount of movement of the user, and a position information acquisition unit that acquires position information of the virtual object, the virtual object generation control unit generates the virtual object and releases it to the user, and transmits the release time of the virtual object to the fall risk assessment unit, the movement amount acquisition unit calculates the acquired movement amount and the position information of the virtual object, The fall risk assessment unit transmits a movement amount acquisition time, which is the time when the movement amount was acquired, to the fall risk assessment unit, and the position information acquisition unit transmits the acquired position information and a position information acquisition time, which is the time when the position information was acquired, to the fall risk assessment unit, and the fall risk assessment unit extracts the movement amount corresponding to the release time and a passing time, which is the position information acquisition time, which corresponds to the position information at which the virtual object coincides with a reference line extending from the center of gravity of the user toward the shoulders, extracts the movement amount corresponding to the extracted passing time, and assesses the fall risk based on the difference between the movement amount corresponding to the extracted release time and the movement amount corresponding to the extracted passing time.

[0007] In the fall risk assessment device, the amount of movement when the user is stationary is a distance of movement of the user in the shoulder direction or an angle of rotation of the user.

[0008] In the fall risk assessment device, the amount of movement when the user is walking is a variation in the walking speed of the user.

[0009] The fall risk assessment device is characterized in that it has a database unit having a assessment table in which the fall risk is stored according to the amount of movement, and the fall risk assessment unit compares the amount of movement with the assessment table to assess the fall risk. [Effects of the Invention]

[0010] The fall risk assessment device of the present invention utilizes virtual reality to easily assess the risk of a user falling based on the amount of movement of the user when avoiding a virtual object. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an explanatory diagram of an overall schematic diagram of a fall risk assessment system according to an embodiment of the present invention; [Figure 2] 1 is an explanatory diagram of a fall risk determination system according to an embodiment of the present invention; [Figure 3] FIG. 3A is an explanatory diagram of a position information time table, and FIG. 3B is an explanatory diagram of a movement amount time table. [Figure 4] FIG. 4A is an explanatory diagram of a moving distance determination table, FIG. 4B is an explanatory diagram of a rotation angle determination table, and FIG. 4C is an explanatory diagram of a walking speed determination table. [Figure 5] 1 is an explanatory diagram of a processing procedure of a fall risk determination system according to an embodiment of the present invention; [Figure 6] FIG. 6A is an explanatory diagram of the display unit before the virtual object is released, and FIG. 6B is an explanatory diagram of the display unit after the virtual object is released. [Figure 7] This shows a case where the user moves and avoids the virtual object. FIG. 7A is an explanatory diagram when the virtual object is released, and FIG. 7B is an explanatory diagram when the user avoids the virtual object. [Figure 8] This is a case where the user rotates to avoid the virtual object. FIG. 8A is an explanatory diagram when the virtual object is released, and FIG. 8B is an explanatory diagram when the user avoids the virtual object. [Figure 9] This shows a case where a user avoids a virtual object while walking. FIG. 9A is an explanatory diagram showing when a virtual object is released, and FIG. 9B is an explanatory diagram showing when the user avoids the virtual object. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram of an overall schematic diagram of a fall risk assessment system 100 according to an embodiment of the present invention. FIG. 2 is an explanatory diagram of a fall risk assessment system 100 according to an embodiment of the present invention. FIG. 3A is an explanatory diagram of a position information time table 16, and FIG. 3B is an explanatory diagram of a movement amount time table 18. FIG. 4A is an explanatory diagram of a movement distance assessment table 22, FIG. 4B is an explanatory diagram of a rotation angle assessment table 24, and FIG. 4C is an explanatory diagram of a walking speed assessment table 26.

[0013] <Configuration of Fall Risk Assessment System 100> The fall risk assessment system 100 includes a fall risk assessment device 10 and a head-mounted display 40. The head-mounted display 40 has a function for generating augmented reality (AR) and is connectable to the fall risk assessment device 10. The head-mounted display 40 and the fall risk assessment device 10 can be connected either by wire or wirelessly.

[0014] The fall risk assessment device 10 includes a virtual object generation control unit 12, a fall risk assessment unit 14, a database unit 20, and an assessment communication unit 28, which are interconnected via a bus 30. The virtual object generation control unit 12 is a means having the function of generating and moving a virtual object 70. Here, the virtual object 70 is an object generated by computer graphics, and is displayed on the HMD communication unit 46 of the head-mounted display 40 in augmented reality.

[0015] The fall risk assessment unit 14 is a means for assessing the risk of a fall of the user 60. Here, the fall risk is a level that indicates the likelihood of the user 60 falling in daily life, expressed in multiple levels. For example, if the fall risk is expressed in three levels, the fall risk levels are fall risk 1, fall risk 2, and fall risk 3, with a higher fall risk level indicating a higher likelihood of falling in daily life. The fall risk assessment unit 14 also includes a position information time table 16 and a movement distance time table 18 (FIGS. 3A and 3B). The position information time table 16 indicates position information L acquired by the position information acquisition unit 44, which will be described later, and the position information acquisition time TL of the position information L. Here, the position information L refers to the position information of the virtual object 70. The position information acquisition time TL refers to the time when the position information of the virtual object 70 is acquired. In the position information time table 16, for example, a position information acquisition time TL1 is stored for the position information L1, and a position information acquisition time TLG is stored for the position information LG. Also, the movement amount time table 18 indicates a movement amount D acquired by a movement amount acquisition unit 42 (described later) and a movement amount acquisition time TD for the movement amount D. Here, the movement amount D refers to the movement amount of the head mounted display 40. Also, the movement amount acquisition time TD refers to the time when the movement amount of the head mounted display 40 is acquired. In the movement amount time table 18, for example, a movement amount acquisition time TD1 is stored for the movement amount D1, and a movement amount acquisition time TLG is stored for the movement amount DG.

[0016] The database unit 20 includes a movement distance determination table 22, a rotation angle determination table 24, and a walking speed determination table 26. The movement distance determination table 22, the rotation angle determination table 24, and the walking speed determination table 26 are determination tables that store fall risk levels corresponding to movement amounts. Specifically, the movement distance determination table 22 shows the relationship between the movement amount of the user 60 that occurs to avoid the virtual object 70 when the virtual object 70 approaches the user 60 and the fall risk level ( FIG. 4A ). In the movement distance determination table 22, the movement amount is the movement distance a. Specifically, if the movement distance a is 0 cm or more and less than 20 cm, the fall risk level is 1; if the movement distance a is 20 cm or more and less than 40 cm, the fall risk level is 2; and if the movement distance a is 40 cm or more, the fall risk level is 3.

[0017] The rotation angle determination table 24 shows the relationship between the rotation angle b of the user 60 and the fall risk level (FIG. 4B). In the database unit 20, the amount of movement is the rotation angle b. Specifically, if the rotation angle b is equal to or greater than 0 degrees and less than 30 degrees, it indicates a fall risk level of 1; if the rotation angle b is equal to or greater than 30 degrees and less than 60 degrees, it indicates a fall risk level of 2; and if the rotation angle b is equal to or greater than 60 degrees and less than 90 degrees, it indicates a fall risk level of 3.

[0018] The walking speed determination table 26 shows the relationship between the amount of change c in the walking speed of the user 60 and the risk of falling ( FIG. 4C ). Here, the amount of change c is the difference between the walking speed before and after the user 60's walking speed is decelerated. Specifically, if the amount of change c is 0 m / s or more and less than 0.3 m / s, the fall risk level is 1; if the amount of change c is 0.3 m / s or more and less than 0.6 m / s, the fall risk level is 2; and if the amount of change c is 60 degrees or more and less than 90 degrees, the fall risk level is 3.

[0019] The determination communication unit 28 is a means for communicating with the head mounted display 40.

[0020] The head-mounted display 40 includes a movement amount acquisition unit 42, a position information acquisition unit 44, an HMD communication unit 46, an imaging unit 48, a head tracking unit 50, an eye tracking unit 52, and a display unit 54, which are interconnected via a bus 56.

[0021] The movement amount acquisition unit 42 is a means for acquiring the amount of movement of the user 60 wearing the head mounted display 40. For example, it is configured with IMUs (Inertial Measurement Units) including an accelerometer, a gyroscope, and a magnetometer.

[0022] The position information acquisition unit 44 is a means for acquiring position information of the virtual object 70. For example, it is configured with a depth sensor including an infrared camera or the like.

[0023] The HMD communication unit 46 is a means for communicating with the fall risk assessment system 100. The imaging unit 48 is a means for the user 60 to view. It is composed of, for example, a camera. The head tracking unit 50 is a means for detecting the direction of the fall risk assessment device 10 worn by the user 60. The head tracking unit 50 includes a visible light camera. The eye tracking unit 52 is a means for detecting the viewing direction of the user 60. The eye tracking unit 52 includes an infrared camera. The display unit 54 is a means for superimposing a virtual object on the real object viewed by the user 60.

[0024] <Explanation of the operation of the fall risk assessment system 100> Next, the operation of the fall risk assessment system 100 will be described with reference to FIGS. 5 to 9. FIG. 5 is an explanatory diagram of the processing procedure of the fall risk assessment device 10 according to an embodiment of the present invention. FIG. 6 is an explanatory diagram, where FIG. 6A is an explanatory diagram of the display unit before a virtual object is released, and FIG. 6B is an explanatory diagram of the display unit after the virtual object is released. FIG. 7 shows a case where a user moves to avoid a virtual object, where FIG. 7A is an explanatory diagram of when the virtual object is released, and FIG. 7B is an explanatory diagram of when the user avoids the virtual object. FIG. 8 shows a case where a user rotates to avoid a virtual object, where FIG. 8A is an explanatory diagram of when the virtual object is released, and FIG. 8B is an explanatory diagram of when the user avoids the virtual object. FIG. 9 shows a case where a user avoids a virtual object while walking, where FIG. 9A is an explanatory diagram of when the virtual object is released, and FIG. 9B is an explanatory diagram of when the user avoids the virtual object.

[0025] A case will be described below in which a virtual object 70 is released toward the user 60, and the user 60 moves to the left or right to avoid a collision with the virtual object 70.

[0026] First, the virtual object generation control unit 12 generates a virtual object 70 and transmits it to the head-mounted display 40 via the determination communication unit 28 (step S1). In this state, an object 72 visible to the user 60 is displayed on the display unit 54 of the head-mounted display 40 via the imaging unit 48 (FIG. 6A). The display content displayed on the display unit 54 is controlled by the head tracking unit 50 according to the angle of the user 60's head, etc., and by the eye tracking unit 52 according to the user 60's line of sight.

[0027] In the head mounted display 40, the virtual object 70 is received via the HMD communication unit 46 and displayed on the display unit 54 as shown in FIG. 6B (step S2).

[0028] The virtual object generation control unit 12 generates a virtual object 70 and releases the virtual object 70 toward the user 60, and also transmits the release time TS (TDS) of the virtual object 70 to the fall risk determination unit 14 (step S3).

[0029] The movement amount acquisition unit 42 acquires the movement amount D of the head-mounted display 40, and transmits the acquired movement amount D and a movement amount acquisition time TD, which is the time when the movement amount D was acquired, to the fall risk determination unit 14 (step S4). In this case, the movement amount D is the movement distance.

[0030] The fall risk determination unit 14 receives the movement amount acquisition time TD and the movement amount D, and stores them in the movement amount time table 18 (step S5).

[0031] The position information acquisition unit 44 acquires the position information L of the virtual object 70, and transmits the acquired position information L and the position information acquisition time TL, which is the time when the position information was acquired, to the fall risk determination unit 14 (step S6).

[0032] The fall risk determination unit 14 receives the position information acquisition time TL and the position information L, and stores them in the position information time table 16 (step S7).

[0033] The fall risk determination unit 14 receives the release time TS, and compares it with the movement amount time table 18 to extract the movement amount D of the head mounted display 40 corresponding to the received release time TS (step S8). Here, it is assumed that the fall risk determination unit 14 acquires the release time TDS from the movement amount acquisition time TD, and extracts the movement amount DS as the movement amount D corresponding to the release time TDS.

[0034] The fall risk determination unit 14 extracts a passing time, which is a position information acquisition time, corresponding to the position information that coincides with the reference line 74 (step S9). Here, the reference line 74 is a virtual line along which the virtual object 70 extends from the center of gravity G of the user 60 in the shoulder direction, as shown in FIGS. 7A and 7B, and is a virtual line for obtaining the passing time when the virtual object 70 passes the user 60 as the user 60 avoids the virtual object 70. Furthermore, the fall risk determination unit 14 compares the position information time table 16 to obtain position information LG of the point where the virtual object 70 passes the reference line 74 from the position information L, and extracts a position information acquisition time TLG (passing time TLG), which is the passing time, as the position information acquisition time TL corresponding to the position information LG. Furthermore, the fall risk determination unit 14 extracts a movement amount DG as a movement amount D corresponding to the passing time TLG extracted from the movement amount time table 18.

[0035] The fall risk determination unit 14 determines the fall risk based on the difference d between the movement amount DS corresponding to the extracted release time TDS and the movement amount DG corresponding to the extracted passage time TLG (step S10). In this case, the user 60 moves to the left or right to avoid a collision with the virtual object 70, so the fall risk is determined from the movement distance determination table 22. For example, if the difference d=30 cm, i.e., the movement distance a=30 cm, the fall risk is 2.

[0036] Next, a case where a virtual object 70 is released toward the user 60, and the user 60 rotates to avoid a collision with the virtual object 70 will be described. In this case, steps S1 to S10 are basically the same as those in the case where the user 60 moves left or right to avoid a collision with the virtual object 70. In this case, the movement amount D becomes the rotation angle b in step S4. The rotation angle b is the angle at which a line extending in the longitudinal direction of the head-mounted display 40 in the posture of the user 60 before avoiding the virtual object 70 shown in FIG. 8A intersects with a line extending in the longitudinal direction of the head-mounted display 40 in the posture of the user 60 immediately after avoiding the virtual object 70 shown in FIG. 8B. In step S10, the fall risk determination unit 14 determines the fall risk for the rotation angle based on the difference d between the movement amount DS corresponding to the extracted release time TDS and the movement amount DG corresponding to the extracted passage time TLG. The fall risk determination unit 14 determines the fall risk based on the rotation angle determination table 24. For example, when the difference d=45 degrees, that is, the rotation angle b=45 degrees, the fall risk level is 2.

[0037] Next, a case where a virtual object 70 is released toward the user 60 and the user avoids the virtual object while walking will be described. In this case, steps S1 to S10 are basically the same as those for the case where the user 60 moves left or right to avoid a collision with the virtual object 70. In this case, in step S4, the amount of movement D is the amount of change in walking speed. In step S6, the walking speed when the virtual object 70 is released toward the user 60 is defined as VA ( FIG. 9A ), and the walking speed when the user 60 avoids the virtual object 70 is defined as VB ( FIG. 9B ). The fall risk determination unit 14 determines the fall risk of the walking speed based on the difference d = VB - VA between the amount of movement DS corresponding to the extracted release time TDS and the amount of movement DG corresponding to the extracted passage time TLG. The fall risk determination unit 14 determines the fall risk based on the walking speed determination table 26. For example, if the difference d=0.5 m / s, that is, the displacement c=0.5 m / s, the fall risk level is 2.

[0038] As described above, the fall risk assessment device is a fall risk assessment device connectable to a head-mounted display 40 that generates augmented reality and is worn by a user 60, and the fall risk assessment device has a virtual object generation control unit 12 that generates and moves a virtual object 70, and a fall risk assessment unit 14 that assesses the fall risk of the user 60, the head-mounted display 40 has a movement amount acquisition unit 42 that acquires the amount of movement of the user 60, and a position information acquisition unit 44 that acquires position information of the virtual object 70, the virtual object generation control unit 12 generates the virtual object 70 and releases it to the user 60, and transmits the release time of the virtual object 70 to the fall risk assessment unit 14, and the movement amount acquisition unit 42 The position information acquisition unit 44 transmits the acquired movement amount and a movement amount acquisition time, which is the time at which the movement amount was acquired, to the fall risk assessment unit 14, and the position information acquisition unit 44 transmits the acquired position information and a position information acquisition time, which is the time at which the position information was acquired, to the fall risk assessment unit 14, and the fall risk assessment unit 14 extracts the movement amount corresponding to the release time and the passing time, which is the position information acquisition time, which corresponds to the position information at which the virtual object 70 coincides with a reference line 74 extending from the center of gravity of the user 60 toward the shoulders, extracts the movement amount corresponding to the extracted passing time, and assesses the fall risk based on the difference between the movement amount corresponding to the extracted release time and the movement amount corresponding to the extracted passing time.

[0039] The fall risk assessment device 10 can easily assess the risk of the user falling based on the amount of movement of the user 60 when avoiding the virtual object 70, using virtual reality.

[0040] In the fall risk assessment device, the amount of movement when the user 60 is stationary is the distance of movement of the user 60 in the shoulder direction or the angle of rotation of the user 60.

[0041] In the fall risk assessment device, the amount of movement when the user 60 is walking is the amount of change in the walking speed of the user 60.

[0042] The fall risk assessment device has a database unit 20 having a assessment table in which the fall risk is stored according to the amount of movement, and the fall risk assessment unit 14 compares the amount of movement with the assessment table to assess the fall risk.

[0043] It should be noted that the present invention is not limited to the above-described embodiment, and various configurations can be adopted without departing from the gist of the present invention.

[0044] For example, in the above-described embodiment, the fall risk is determined based on either the movement distance or the rotation angle as the amount of movement, but this is not limited to this as long as the fall risk can be determined. Both the movement distance and the rotation angle may be obtained, and a fall risk based on the movement distance and a fall risk based on the rotation angle may be obtained, and the greater fall risk may be used as the determined fall risk for the user 60.

[0045] In the above-described embodiment, the fall risk is determined based on the difference in movement speed, which is the amount of displacement, as the amount of movement, but this is not limited to this as long as the fall risk can be determined. In addition to the difference in movement speed, both the movement distance and the rotation angle may be obtained, and a fall risk based on the movement distance, a fall risk based on the rotation angle, and a fall risk based on the amount of displacement may be obtained, and the highest fall risk may be used as the determined fall risk for user 60. [Explanation of symbols]

[0046] 10...Fall risk assessment device 12...Virtual object generation control unit 14...Fall risk assessment section 16...Location information time table 18...Movement time table 20...Database Department 22...Movement distance determination table 24...Rotation angle judgment table 26...Walking speed judgment table 28…Judgment communication department 30, 56... Bus 40...Head-mounted display 42...Movement amount acquisition section 44...Position information acquisition unit 46…HMD Communications Department 48...Photography Department 50...Head tracking unit 52...Eye tracking section 54...Display section 60…User 70...Virtual Objects 72...Object 74...Baseline 100...Fall risk assessment system

Claims

1. A fall risk assessment device that generates augmented reality and is connectable to a head-mounted display worn by a user, The fall risk assessment device includes: a virtual object generation control unit that generates and moves a virtual object; a fall risk determination unit for determining a fall risk of the user; and The head-mounted display includes: a movement amount acquisition unit that acquires the movement amount of the user; a position information acquisition unit that acquires position information of the virtual object; and the virtual object generation control unit generates the virtual object, releases it to the user, and transmits a release time of the virtual object to the fall risk determination unit; the movement amount acquisition unit transmits the acquired movement amount and a movement amount acquisition time, which is a time when the movement amount was acquired, to the fall risk determination unit; the location information acquisition unit transmits the acquired location information and a location information acquisition time, which is a time when the location information was acquired, to the fall risk assessment unit; The fall risk determination unit extracting the movement amount corresponding to the release time and a passage time which is the position information acquisition time corresponding to the position information at which the virtual object coincides with a reference line extending from the center of gravity of the user toward the shoulders, and extracting the movement amount corresponding to the extracted passage time; The fall risk is determined based on a difference between the movement amount corresponding to the extracted release time and the movement amount corresponding to the extracted passage time. A fall risk assessment device characterized by:

2. The fall risk assessment device according to claim 1, The amount of movement when the user is stationary is the distance the user has moved in the shoulder direction or the angle of rotation of the user. A fall risk assessment device characterized by:

3. The fall risk assessment device according to claim 1, The amount of movement when the user is walking is the amount of change in the walking speed of the user. A fall risk assessment device characterized by:

4. The fall risk assessment device according to claim 2 or 3, a database unit having a determination table in which a fall risk level is stored according to the amount of movement; The fall risk determination unit compares the amount of movement with the determination table to determine the fall risk. A fall risk assessment device characterized by:

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