KR102255342B1 - Rehabilitation apparatus for improving vestibulo-ocular reflex based on virtual reality games and multiple bio-signal sensors - Google Patents

Abstract

The present invention relates to a virtual reality game and a complex bio-signal sensor-based, which uses an eye tracker attached or installed on a head-worn display device, and an inertial measurement sensor (IMU sensor). A sensing unit for sensing and notifying movement; When a VOR (Vestibulo-Ocular Reflex) function evaluation is requested, a VOR function evaluation unit that obtains a VOR gain by calculating and quantifying a head-to-eye movement ratio after configuring and providing a game for evaluating a VOR function; When a rehabilitation exercise is requested, a patient-customized control unit that determines a type and order of rehabilitation games and a rehabilitation level based on the patient's VOR gain; And a game for at least one of smooth follow-up exercise, intermittent exercise, VOR rehabilitation exercise, amplified VOR rehabilitation exercise, and suppression VOR rehabilitation exercise according to the type and sequence of the rehabilitation game, but the game difficulty is adjusted according to the rehabilitation level. It may include a rehabilitation game providing unit to determine.

Description

TECHNICAL FIELD [Rehabilitation apparatus for improving vestibulo-ocular reflex based on virtual reality games and multiple bio-signal sensors}

The present invention evaluates the vestibular-ocular reflex function using a head-worn display device, an eyetracker, and an inertial measurement sensor (IMU sensor, gyrosensor), and performs a rehabilitation exercise optimized for the vestibular-ocular reflex function in virtual reality. It relates to a vestibular-ocular reflex rehabilitation device based on a virtual reality game and a complex bio-signal sensor that can be played in a game manner.

The vestibular function can be expressed as vestibulo-ocular reflex (VOR), which, in brief, refers to a function that induces eye movement in the opposite direction in which the head rotates. Through VOR, animals, including humans, can continuously watch a specific point or object regardless of head movement.

When vestibular dysfunction occurs in which the function of the vestibular organs located in both inner ears is damaged due to various causes, an abnormality occurs in the VOR, and the phenomenon that the gaze cannot rotate in the opposite direction as the head rotates occurs. .

Such vestibular dysfunction can be improved through vestibular rehabilitation exercises composed of various gaze and head rotation exercises. However, the conventional vestibular rehabilitation exercise is composed of a program that simply repeats actions such as eye rotation, head rotation, etc., so that interest is easily reduced, and thus the actual trial rate is very low.

In the conventional vestibular rehabilitation exercise, the same program is configured and provided irrespective of the degree of reduction in vestibular function, so that customized treatment for each patient is impossible. In addition, there is a problem that the efficiency of treatment is deteriorated by continuously providing the same program without considering the vestibular function that improves through rehabilitation training and natural recovery process.

On the other hand, in order to measure the vestibular function, there is an inconvenience of visiting a hospital and performing an expensive vestibular function test, and since the vestibular function must be measured using a separate vestibular function measuring device, it is not possible to measure the vestibular function during rehabilitation exercise. There is a limit.

In addition, in order to evaluate the improvement of the function of visual function training, which is used as a sensory substitution method, it is necessary to visit a hospital and evaluate it through expensive existing measuring equipment. It has a limit to bear.

Korean Patent Publication 10-2016-0005519 (Publication date: January 15, 2016)

Accordingly, as to solve the above problems, the present invention is a virtual device that enables real-time evaluation of the patient's VOR function using a head-worn display device, an eye tracker, and an inertial measurement sensor (IMU sensor, gyrosensor). It is intended to provide a vestibular-ocular reflex rehabilitation device based on a real game and a complex bio-signal sensor.

In addition, it is intended to provide a virtual reality game that enables rehabilitation exercises optimized for the patient's VOR function to be performed in a virtual reality game method, and a vestibular-ocular reflex rehabilitation device based on a complex bio-signal sensor.

The object of the present invention is not limited to the above-mentioned object, and other objects not mentioned will be clearly understood by those of ordinary skill in the art from the following description.

As a means for solving the above problems, according to an embodiment of the present invention, in a virtual reality game and a vestibular-ocular reflex rehabilitation device based on a complex bio-signal sensor, an eye tracker attached or installed on a head-worn display device ), a sensing unit for sensing and notifying the movement of the patient's head and the eyeball using an inertial measurement sensor (IMU sensor); When a VOR (Vestibulo-Ocular Reflex) function evaluation is requested, a VOR function evaluation unit that obtains a VOR gain by calculating and quantifying a head-to-eye movement ratio after configuring and providing a game for evaluating a VOR function; When a rehabilitation exercise is requested, a patient-customized control unit determining a type and order of rehabilitation games and a rehabilitation level based on the patient's VOR gain; And a game for at least one of smooth follow-up exercise, intermittent exercise, VOR rehabilitation exercise, amplified VOR rehabilitation exercise, and suppression VOR rehabilitation exercise according to the type and sequence of the rehabilitation game, but the game difficulty is adjusted according to the rehabilitation level. It provides a virtual reality game-based vestibular-ocular reflex rehabilitation device including a rehabilitation game providing unit to determine.

The patient customized control unit may further include a function of adjusting the type and order of the rehabilitation game, and the rehabilitation level at any time in consideration of the game result of the rehabilitation game providing unit while the rehabilitation exercise is being performed.

The VOR function evaluation unit is characterized by inducing a VOR by constructing and providing a game that causes the head to rotate at a preset angle and speed by looking at the gaze target on the screen.

The rehabilitation game providing unit constructs and provides a game to track a gaze target in which the gaze moves smoothly at a predetermined speed when a smooth follow-up exercise is requested, and then calculates and analyzes the eye movement ratio to the gaze target to determine whether the game is cleared. It is characterized by determining.

The rehabilitation game providing unit constructs and provides a game to track a gaze target in which the gaze is instantaneously moved from one place to another when intermittent gaze movement is requested, and then calculates and analyzes the eye movement ratio to the gaze target to play the game. It is characterized in that it is determined whether or not to clear.

When a VOR rehabilitation exercise is requested, the rehabilitation game provider configures and provides a game in which only the head rotates at a preset angle and speed while fixing the gaze, and then calculates and analyzes the eye movement ratio to the gaze target to clear the game. Characterized in determining whether or not.

When amplified VOR rehabilitation exercise is requested, the rehabilitation game provider provides a game that causes head movement of a preset angle and speed, while the gaze target is rotated more than a certain rate compared to head rotation, thereby causing a larger range of eye movement. After composition and provision, it is characterized in determining whether to clear the game by calculating and analyzing the ratio of eye movement relative to the gaze target.

The rehabilitation game providing unit configures and provides a game that causes eye movement to suppress rotation of the head at a certain rate compared to the rotation of the head while inducing a head movement of a preset angle and speed when a suppression VOR rehabilitation movement is requested. After that, it is characterized in that it is determined whether or not to clear the game by calculating and analyzing the ratio of eye movement relative to the gaze target.

The rehabilitation game providing unit monitors the patient's degree of concentration, and further includes a function of additionally generating and providing information for alerting attention when the degree of concentration falls by more than a preset value.

The rehabilitation game providing unit may adjust the game difficulty through at least one of a movement speed of a gaze target, a rotation speed of a head, and a movement speed of a background screen.

The present invention makes it possible to more simply and easily evaluate the vestibular-eye reflex function of an individual patient using a head-worn display device, an eye tracker, and an inertial measurement sensor.

In addition, a virtual reality game type of vestibular rehabilitation can be performed, but the game difficulty can be adjusted at any time according to the VOR function, thereby enabling patient-specific and motivational vestibular rehabilitation exercises.

1 is a diagram illustrating a vestibular-ocular reflex rehabilitation apparatus based on a game method according to an embodiment of the present invention.
2 is a diagram showing a detailed configuration of a sensing unit according to an embodiment of the present invention.
3 is a diagram for describing a method of evaluating a VOR function according to an embodiment of the present invention.
4 is a view for explaining a method of providing a rehabilitation game according to an embodiment of the present invention.
5 is a diagram illustrating an example of a game screen for supporting a smooth follow-up exercise according to an embodiment of the present invention.
6 is a diagram illustrating an example of a game screen for supporting intermittent gaze movement according to an embodiment of the present invention.
7 is a diagram illustrating an example of a game screen for supporting VOR rehabilitation exercise according to an embodiment of the present invention.
8 is a diagram illustrating an example of a game screen for supporting an amplified VOR rehabilitation exercise according to an embodiment of the present invention.
9 is a view showing an example of a game screen for supporting the suppression VOR rehabilitation exercise according to an embodiment of the present invention.

Objects and effects of the present invention, and technical configurations for achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. In describing the present invention, if it is determined that a detailed description of a known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of the patient or operator.

However, the present invention is not limited to the embodiments disclosed below, and may be implemented in various different forms. The present embodiments are provided only to make the disclosure of the present invention complete, and to fully inform the scope of the invention to those skilled in the art to which the present invention pertains, and the present invention is defined by the scope of the claims. It just becomes. Therefore, the definition should be made based on the contents throughout the present specification.

1 is a diagram illustrating a vestibular-ocular reflex rehabilitation apparatus based on a game method according to an embodiment of the present invention.

As shown in FIG. 1, the vestibular function rehabilitation apparatus 100 of the present invention is a device that interlocks with a head-worn display device 200 capable of reproducing an image in a virtual reality method, and includes a sensing unit 110 and a VOR. (Vestibulo-Ocular Reflex) includes an evaluation unit 120, a patient custom control unit 130, and a rehabilitation game providing unit 140.

In this case, the head-worn display device 200 may be implemented as an HMD (Head Mounted Display) that covers the entire eye, a glasses-type display in which only a small display is applied near the user's eyes, and the like, which provides an image such as a game screen in a virtual reality method. By playing back, the patient can provide a sense of immersion as if they exist in the virtual reality world.

The sensing unit 110 includes a motion sensor 111 and a gaze tracker 112 attached or installed on a head-worn display device, and senses and outputs the movement of the patient's head and the eyeball through them.

When the VOR function evaluation is requested by the patient, the VOR function evaluation unit 120 fixes the gaze target in the center of the screen and plays a game that simultaneously induces the movement of the eyeball and the head through the game screen in which the background screen is rotated at an angle. Organize and provide. In addition, the VOR gain is obtained and stored by calculating and quantifying a head-to-eye movement ratio based on the sensing result of the sensing unit 110.

For reference, in actual daily life, the above-described head rotation and eye movement occur at the same time, and the rehabilitation movement that moves in various directions and speeds (angular velocity, angular acceleration) as well as the head rotation at the same time is difficult, but the most realistic form of rehabilitation movement is. do. For example, if the gaze target moves to the left while the head is moving to the right, the eye movement system must be activated in addition to VOR, so the weighting effect of the two functions can be seen. Conversely, if the gaze target is also moved to the right while the head is moving to the right, the VOR that moves the eyeball in the same direction against the head rotation must be suppressed. Thus, although it may seem simple, the two configurations are methods of evaluating and rehabilitation of completely different functions physiologically.

Accordingly, in the present invention, the head and the eyeball are simultaneously moved through the VOR function evaluation unit 120, and the VOR function is evaluated by comparing and analyzing the movement pattern at this time.

When a rehabilitation exercise is requested, the patient customized control unit 130 determines the type and order of the rehabilitation game of the patient, and the rehabilitation level based on the patient's VOR gain. In addition, while the rehabilitation exercise is being performed, the type and order of the rehabilitation game, and the rehabilitation level are adjusted at any time in consideration of the game result of the rehabilitation game providing unit 140.

The rehabilitation game providing unit 140 determines the type and order of rehabilitation games to be provided to the patient according to the type and order of the rehabilitation games determined by the patient customization control unit 130, and adjusts the game difficulty according to the rehabilitation level. At this time, the game difficulty is determined by at least one of the movement range of the screen including the head rotation, the gaze target, and the movement speed (i.e., at least one of angular speed and angular acceleration), and the gaze target or the background screen moves in proportion to the game difficulty. Allows range and movement speed to increase. That is, based on the patient's VOR gain and rehabilitation exercise history, the patient's condition is identified, and based on this, a rehabilitation game optimized for the patient's condition can be customized and provided.

For reference, vestibular rehabilitation exercises include a smooth pursuit that gently observes a moving target, a saccade that moves the gaze from one place to another quickly, and a size proportional to the head rotation. There is a VOR rehabilitation exercise (VOR) that induces eye movement at and speed and induces a specific target point to be observed.

Along with this, in order to increase the effect of VOR rehabilitation, an augmentation VOR rehabilitation mode that rotates the gaze target more than the size or speed of the head rotation in the opposite direction of rotation when the head rotation occurs. Conversely, such as head rotation. It includes a suppression VOR rehabilitation mode that limits the target movement in the opposite direction to the rotation when the head rotates to stably gaze at an object moving in the direction.

Accordingly, in the present invention, a game for at least one of smooth follow-up exercise, intermittent gaze exercise, VOR rehabilitation exercise, amplified VOR rehabilitation exercise, and suppressed VOR rehabilitation exercise can be selectively configured and provided according to the patient's VOR function and purpose.

In addition, the rehabilitation game providing unit 140 monitors the patient's concentration level, and when the concentration level falls by more than a preset value, additional information for attention ventilation can be generated and provided.

At this time, the patient's concentration may be inferred based on the visual target gaze frequency, gaze time, and eye closing pattern sensed through the gaze tracker 112, or from a change pattern of the game score (i.e., a sudden drop in game score). have. In addition, the information for alerting attention may be implemented and provided in a manner of changing the size, color, and shape (eg, change to a scary image or acquaintance photo) of a gaze target and a background screen, or a sound stimulation method.

As described above, the present invention increases the accuracy and efficiency of rehabilitation exercises and reduces manpower for the rehabilitation program.

2 is a diagram showing a detailed configuration of a sensing unit according to an embodiment of the present invention.

Referring to FIG. 2, the sensing unit 110 includes a motion sensor 111, a gaze tracker 112, and a synchronization unit 113.

The motion sensor 111 is implemented through at least one of an angular velocity sensor, an acceleration sensor, a gravity sensor, and a compass sensor, and senses and reports the movement of the user's head in three dimensions.

The gaze tracker 112 senses and reports eye movement (ie, gaze) based on the iris or pupil.

The synchronization unit 113 synchronizes and outputs the movement of the user's head and the movement of the eyeball based on time. This is to make it possible to compare the degree of movement of the user's head and the degree of eye movement based on the same time.

3 is a diagram illustrating a method of evaluating a VOR function according to an embodiment of the present invention.

If a patient or medical staff requests VOR function evaluation through the operation panel 150, the VOR function evaluation unit 120 induces a head rotation of a preset angle and speed (acceleration) as shown in Fig. 3(a). By configuring and providing a game screen in which the entire virtual reality (VR) screen including the visual target and the background screen rotates in the opposite direction of the head rotation, the patient has fixed his or her gaze to the gaze target. Induces head rotation in direction and speed.

When the VOR is in a normal state, the patient continues to look at the gaze target at the center of the screen while the gaze rotates in the same direction and size in the opposite direction to the head rotation direction as shown in FIG. 3B.

However, in the VOR or higher state, the patient cannot rotate his gaze as much as the head movement angle as shown in FIG. 3(c), and a predetermined deviation occurs between the eyeball movement angle and the head movement angle.

Accordingly, in the present invention, the movement angle and movement speed of the head and the eyeball are measured using the movement sensor 111 and the eye tracker 112, and whether the VOR function is abnormal based on the head-to-eye movement ratio (ie, VOR gain). Furthermore, let the VOR function determine the degree of anomaly. In particular, in the present invention, the VOR gain is determined by dividing the moving speed from the angular velocity and the angular acceleration, so that a more detailed VOR gain calculation operation can be performed.

[Equation 1]

delete

That is, if the VOR gain is close to “1” (for example, if it is 0.8 or more), the VOR is in a normal state, and the closer to “0”, the greater the degree of VOR abnormality is confirmed and notified.

In addition, when such rotational motion is performed in the left and right directions, the gain is measured close to normal on the side where the VOR function is normal, but if an abnormality occurs in the VOR function, the gain decreases. Therefore, by comparing the gains of the left and right rotational movements, it is possible to calculate the asymmetry of the vestibular-ocular reflex function, and based on this, it is possible to distinguish the side of the lesion where the VOR abnormality occurred. This is simply summarized in the equation as follows.

[Equation 2]

4 is a view for explaining a method of providing a rehabilitation game according to an embodiment of the present invention.

First, based on the VOR gain, the type, order, and game difficulty of the rehabilitation game to be provided to the patient are determined. That is, the patient state is inferred based on the VOR gain, and a rehabilitation schedule optimized for the patient state is determined and stored (S1).

If the current game to be provided to the patient is a smooth follow-up exercise game (S2), the rehabilitation game providing unit 140 constructs and provides a game screen in which the gaze target is smoothly moved at a predetermined speed, as shown in FIG. The gaze goal is continued to induce gaze tracking (S3).

Then, the eye movement angle is sensed using the gaze tracker 112 (S4).

Then, after comparing the eye movement angle and the gaze target movement angle, the eyeball movement ratio (Oculomotor gain) is calculated, and then the game is compared with a preset game target value (for example, 0.8) to determine whether the game is cleared ( S5).

The game is repeatedly provided until the patient clears the game, but if the patient clears the game, the rehabilitation schedule is updated to reflect the game result, and the next game to be provided is checked (S6).

Accordingly, if the game to be provided to the patient is a game for intermittent gaze exercise (S7), the rehabilitation game providing unit 140 constructs and provides a game screen to appear in another location as soon as the gaze target disappears from the existing location as shown in FIG. 6. While, inducing the patient to accurately observe each gaze target in turn (S8).

Then, the eye movement angle is sensed using the gaze tracker 112 (S9), the eye movement angle and the gaze target movement angle are compared and analyzed to calculate an eye movement ratio (Oculomotor gain) to the gaze target. Then, it is determined whether the game is cleared by comparing the eye movement ratio (Oculomotor gain) to the gaze target with a preset game target value (eg, 0.9) (S10).

[Equation 3]

When the patient clears the game, the patient proceeds to step S6, updates the rehabilitation schedule by reflecting the game progress result, and then proceeds to the next game (S6).

Accordingly, if the game to be provided to the patient is a VOR rehabilitation exercise game (S11), the rehabilitation game providing unit 140 configures and provides a game screen in which the gaze target rotates the head at a preset angle and speed, so that the patient gazes at his or her gaze. Is fixed to the gaze target, and induces the head to rotate (S12).

Then, the head movement angle and the eyeball movement angle are simultaneously sensed using the motion sensor 111 and the gaze tracker 112 (S13), and the ratio of the movement of the eyeball to the head is calculated by comparing and analyzing them. Then, it is determined whether or not the game is cleared by comparing it with a predetermined game target value (eg, 0.8) based on the ratio of eye movement to the head (S14).

Accordingly, when the patient clears the game, the rehabilitation schedule is updated to reflect the game progress result by entering step S6, but when all games are cleared, the rehabilitation level is raised by one level (S6). In other words, it is also possible to determine the rehabilitation level by considering the rehabilitation exercise history in addition to the VOR gain.

In addition, the method of providing a rehabilitation game of the present invention can additionally configure and provide a game for augmentation VOR rehabilitation mode and suppression VOR rehabilitation mode as shown in FIGS. 8 and 9. do.

First, as shown in FIG. 8, for augmentation VOR rehabilitation mode, a game screen is configured and provided in the same principle as VOR rehabilitation, but the degree of movement of the gaze target is amplified and provided.

In other words, while constructing and providing a game screen in which the gaze target is rotated at a certain ratio (1.1 times, 1.2 times, 1.5 times, etc.) in the opposite direction to the head rotation compared to the VOR rehabilitation exercise, the eyeball and head movements at this time are measured and analyzed. By doing so, it is possible to evaluate and rehabilitate VOR and visual motor functions.

On the other hand, as shown in FIG. 9, for suppression VOR rehabilitation mode, the game screen is configured and provided in the same principle as the VOR rehabilitation exercise, but the degree of movement of the gaze target is suppressed and provided.

In other words, by constructing and providing a game screen that reduces the size or speed at which the gaze target rotates in the opposite direction to the head rotation by a certain ratio (0.9 times, 0.8 times, 0.5 times, etc.), by measuring and analyzing the eyeball and head movement at this time. , VOR exercise and visual motor function are evaluated and rehabilitated.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

Claims (10)

In a virtual reality game and a complex bio-signal sensor-based vestibular-ocular reflex rehabilitation device,
A sensing unit for sensing and notifying the movement of the patient's head and the eye by using an eye tracker and an inertial measurement sensor attached or installed on a head-worn display device;
When a VOR (Vestibulo-Ocular Reflex) function evaluation is requested, a VOR function evaluation unit that obtains a VOR gain by calculating and quantifying a head-to-eye movement ratio after configuring and providing a game for evaluating a VOR function;
When a rehabilitation exercise is requested, a patient-customized control unit that determines a type and order of rehabilitation games and a rehabilitation level based on the patient's VOR gain; And
Depending on the type and order of the rehabilitation game, a game for at least one of smooth follow-up exercise, intermittent exercise, VOR rehabilitation exercise, amplified VOR rehabilitation exercise, and suppression VOR rehabilitation exercise is configured and provided, but the game difficulty is adjusted according to the rehabilitation level. It includes a rehabilitation game provider to determine,
The VOR function evaluation unit
Gaze is a virtual reality game-based vestibular-ocular reflex rehabilitation device, characterized in that by inducing VOR by constructing and providing a game that observes the gaze target of the screen and causes head rotation at a preset angle and speed. The method of claim 1, wherein the patient customized control unit
While the rehabilitation exercise is being performed, a virtual reality game-based vestibular-ocular rehabilitation rehabilitation further comprises a function of adjusting the type and order of the rehabilitation game and rehabilitation level at any time in consideration of the game result of the rehabilitation game provider. Device. delete The method of claim 1, wherein the rehabilitation game providing unit
When a smooth follow-up movement is requested, a game is configured and provided to track a gaze target, where the gaze moves smoothly at a predetermined speed, and then the game is determined whether or not to clear the game by calculating and analyzing the eye movement ratio to the gaze target. A virtual reality game-based vestibular-optic reflex rehabilitation device. The method of claim 1, wherein the rehabilitation game providing unit
When intermittent gaze movement is requested, the game is configured and provided to track gaze targets in which the gaze is teleported from one place to another, and then the ratio of eye movement relative to the gaze target is calculated and analyzed to determine whether to clear the game. A virtual reality game-based vestibular rehabilitation device, characterized in that. The method of claim 1, wherein the rehabilitation game providing unit
When a VOR rehabilitation exercise is requested, a game in which only the head is rotated at a preset angle and speed while the gaze is fixed, and then the ratio of eye movement relative to the gaze target is calculated and analyzed to determine whether to clear the game. A virtual reality game-based vestibular-ocular reflex rehabilitation device characterized by. The method of claim 1, wherein the rehabilitation game providing unit
When amplified VOR rehabilitation exercise is requested, a game that triggers a larger range of eye movement by causing the head movement of a preset angle and speed while the gaze target is rotated more than a certain percentage compared to the head rotation. , A virtual reality game-based vestibular-ocular reflex rehabilitation device, characterized in that determining whether to clear the game by calculating and analyzing the eye movement ratio relative to the gaze target. The method of claim 1, wherein the rehabilitation game providing unit
When a suppression VOR rehabilitation exercise is requested, a game that induces eye movement that suppresses the rotation of the head at a predetermined angle and speed while the gaze target is rotated at a certain rate less than the rotation of the head is constructed and provided, and then the gaze target A virtual reality game-based vestibular-ocular reflex rehabilitation device, characterized in that determining whether or not to clear the game by calculating and analyzing the ratio of eye movement. The method of claim 1, wherein the rehabilitation game providing unit
A virtual reality game-based vestibular-ocular rehabilitation rehabilitation device that monitors the patient's concentration, but further includes a function of generating and providing additional information for alerting attention when the concentration falls above a preset value. The method of claim 1, wherein the rehabilitation game providing unit
A virtual reality game-based vestibular-eye rehabilitation rehabilitation device, characterized in that the game difficulty is adjusted through at least one of a movement speed of a gaze target, a rotation speed of a head, and a movement speed of a background screen.

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