Smartphone and virtual reality headset based cervical range of motion acquisition system

Abstract

A cervical activity acquisition system based on a smart phone and a virtual reality head-mounted device, comprising a VR head-mounted device (virtual reality head-mounted device), the VR head-mounted device clamps a smart phone, direction sensor data is acquired through a sensor API of an Android system and is converted into cervical activity data, an optimal adaptive global moving average line of the cervical activity data is extracted using an extreme point symmetry modal decomposition (ESMD) method, and cervical activity is calculated, so that the cervical activity can be continuously measured quickly and conveniently; the cervical activity acquisition system can be used for simple measurement of cervical activity, a plurality of indexes can be measured through one test, and has the advantages of high measurement efficiency and good operability.

Description

Technical Field

[0001] This invention belongs to the field of cervical spine mobility measurement technology, and specifically relates to a cervical spine mobility acquisition system based on a smartphone and a virtual reality headset. Background Technology

[0002] The cervical spine is the most flexible, has the highest frequency of movement, and bears the greatest weight in the human spine, making it an important component of the spine. With the fast pace of life, prolonged sitting and lack of activity make people prone to symptoms such as cervical spondylosis. Cervical spondylosis is a common disease that can induce many complications such as lower limb paralysis and dysphagia. In the diagnosis and treatment of cervical spondylosis, the measurement of cervical range of motion plays an important role and can be an integral part of the diagnosis of cervicogenic headache, radicular cervical spondylosis, and clinical assessment of cervical spine injury (Snodgrass SJ, Cleland JA, Haskins R, et al. The clinical utility of cervical range of motion in diagnosis, prognosis, and evaluating the effects of manipulation: a systematic review[J]. Physiotherapy, 2014, 100(4):290-304.).

[0003] There are various existing methods for obtaining cervical spine mobility, such as electric goniometers, cervical spine mobility compass measuring instruments, tape measure measurement, visual inspection, and X-ray measurement. However, these methods using tools and X-rays are expensive and have low measurement accuracy. The above measuring instruments and methods have some shortcomings in application, mainly in low measurement efficiency and poor operability. Even cervical spine mobility compass measuring instruments cannot simultaneously measure multiple cervical spine mobility indicators and are easily affected by the subject's own behavior or the operator's operation, leading to measurement errors.

[0004] Acquiring cervical spine mobility is of positive significance in helping doctors understand the degree of neck movement in patients and compare the effects before and after rehabilitation. Further research is needed on how to quickly and conveniently measure cervical spine mobility continuously. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention aims to provide a cervical spine mobility acquisition system based on a smartphone and a virtual reality head-mounted device, which can quickly and conveniently measure cervical spine mobility continuously, and has the advantages of high measurement efficiency and good operability.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A cervical spine mobility acquisition system based on a smartphone and a virtual reality headset includes a VR headset (virtual reality head-mounted device), with the VR headset holding the smartphone. The system acquires orientation sensor data through the sensor API of the Android system and converts it into cervical spine mobility data. The optimal adaptive global mean of the cervical spine mobility data is extracted using the extreme symmetric mode decomposition (ESMD) method, and the cervical spine mobility is calculated. This system enables rapid and convenient continuous measurement of cervical spine mobility.

[0008] The smartphone display side is kept relatively parallel to the human face, and the change in neck angle is equivalent to the change in phone angle. That is, the change in longitudinal tilt angle corresponds to lateral flexion, the change in transverse tilt angle corresponds to neck flexion and extension, and the change in azimuth angle corresponds to neck rotation.

[0009] The smartphone has a built-in gravity acceleration sensor and a geomagnetic field sensor. Its orientation sensing data is calculated using the accelerometer value and the geomagnetic field sensor value. By initializing the accelerometer sensor and the geomagnetic field sensor, the orientation sensing data of the smartphone is obtained, and then the changes in the phone's rotation angle, namely the tilt angle, pitch angle and azimuth angle, are obtained.

[0010] The Bluetooth remote control is used to start and stop the human neck movement angle test. At the end of the test, the timestamp and cervical spine movement data are recorded.

[0011] Before starting the human neck movement angle test, the human torso and head are perpendicular to the ground, and the torso and shoulders are kept still. The "zero setting" is adjusted as the initial position, which is used as a reference for subsequent tests.

[0012] The neck movement angle is displayed simultaneously on the left and right screens of the VR headset, showing the lateral flexion, extension, and rotation values ​​of the neck. Users can directly see the current changes in cervical spine mobility. The VR headset directly displays the current human neck movement angle values, records a complete set of neck flexion, extension, rotation, and lateral flexion movement data, processes the data to obtain the maximum and minimum values ​​of flexion, extension, rotation, and lateral flexion, reflects the range of neck movement, and comprehensively evaluates the human neck movement status.

[0013] The extreme point symmetric mode decomposition (ESMD) method was used to extract the trend term from the cervical spine mobility data. Based on the characteristics of the cervical spine mobility data, the maximum number of screening times and the number of remaining poles of the ESMD method were set to remove extreme measurement data of cervical spine mobility. The results were then statistically analyzed.

[0014] The beneficial effects of this invention are:

[0015] Based on Android, this invention system acquires information from the phone's orientation sensor, uses a VR headset as a clamping device, and uses a Bluetooth remote control to set the initial position. It can display real-time information on changes in cervical spine mobility and record and analyze cervical spine mobility data.

[0016] This invention provides a simple way to measure cervical spine mobility. Compared with traditional methods for measuring cervical spine mobility, this invention can measure multiple indicators in a single test, and has the advantages of continuous measurement and convenience. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the system test principle of the present invention.

[0018] Figure 2 This is a schematic diagram of the neck movement mode of the present invention.

[0019] Figure 3 This is a schematic diagram of how the device of the present invention is worn.

[0020] Figure 4 This is a schematic diagram showing the relationship between the mobile phone coordinate system and the head coordinate system of the present invention.

[0021] Figure 5 This is a flowchart of the testing process and data analysis of the present invention. Detailed Implementation

[0022] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0023] Reference Figure 1-2 A cervical spine mobility acquisition system based on a smartphone and a virtual reality headset includes a VR headset (virtual reality head-mounted device), which holds a smartphone and acquires orientation sensor data from the smartphone. The orientation sensor data is converted into cervical spine mobility data after angle conversion, adapting to the range of motion of the human neck, and realizing real-time display, recording, and processing of neck movement angles. The VR headset phone box serves as a clamping device, in which the smartphone is placed and fixed. The display side of the smartphone is kept relatively parallel to the human face. Changes in neck angle are equivalent to changes in phone angle, i.e., changes in the longitudinal tilt angle correspond to lateral flexion, changes in the transverse tilt angle correspond to neck flexion and extension, and changes in the azimuth angle correspond to neck rotation.

[0024] When the human head to torso is perpendicular to the ground, orientation data is acquired via a smartphone's API. This orientation data can be synthesized from accelerometer and geomagnetic field sensor data; azimuth angle Φ X The angle between the phone's Y-axis and the north direction of the Earth's magnetic field, i.e., the angle between the top of the phone and true north (0 to 360°); the tilt angle Φ Y The angle formed by the top or bottom of the phone tilting up relative to the horizontal plane (-90° to 90°); tilt angle Φ z The angle formed by the left or right side of the phone tilting up relative to the horizontal plane (-180° to 180°).

[0025] Reference Figure 3-4 Based on the fixed relative relationship between the phone's orientation sensor and the human body, the angle range is converted to adapt to the relative range of neck movement. The phone's posture changes maintain a fixed relative relationship with the human neck movement, meaning the phone's posture changes follow the human neck movement. Since the initial phone posture is with the phone's X-axis perpendicular to the ground, the directly acquired phone orientation sensor data does not match the initial human posture angle, thus requiring angle conversion. Taking the phone's tilt angle data when the X-axis is perpendicular to the ground as an example, the phone's tilt angle in this posture is -90°, and the range of the phone's tilt angle during neck flexion and extension is 0 to -180°. To adapt to the range of neck movement angle changes corresponding to the current human posture, the phone's tilt angle (-90°) in this posture is used as the zero point for neck flexion and extension. Adding 90° to the phone's tilt angle converts the neck movement angle during neck flexion and extension movements to -90° to 90°.

[0026] Reference Figure 1 , Figure 4 During initial position adjustment, the phone's X-axis should be kept perpendicular to the ground as much as possible. "Zero setting" sets the current flexion / extension, rotation, and lateral flexion values ​​to 0. As the neck flexes, extends, and rotates, the lateral flexion, extension, and rotation values ​​will have positive or negative values, corresponding to the two directions of neck movement: left / right flexion, forward / backward flexion / extension, and left / right rotation. To better display the neck movement angle to the tester in real time, based on the characteristics of the VR headset / phone box, the neck movement angle is displayed in a split-screen format (left and right).

[0027] Reference Figure 5 This invention relates to a cervical spine mobility acquisition system based on a smartphone and a virtual reality headset. It acquires information from the phone's built-in sensors, uses the VR headset as a clamping tool, and combines the phone's orientation sensors with the angular correspondence between human cervical spine mobility to convert orientation sensor data into human cervical spine mobility data. The program interface displays the human cervical spine mobility in real-time on a split-screen basis, allowing the user to directly see the current changes in cervical spine mobility. A Bluetooth remote control is used to start and stop the test, and a timestamp and cervical spine mobility data are recorded at the end of the test. To reduce the influence of sensor noise, the ESMD method is used to extract the optimal adaptive global moving average of the data, reducing jitter in the cervical spine mobility data. ESMD is a method that uses internal extreme point symmetric interpolation to decompose different modes while extracting an adaptive global moving average of the data; the extreme values ​​are calculated to obtain the cervical spine mobility.

[0028] Reference Figure 3-5A cervical spine mobility acquisition system based on smartphones and virtual reality headsets displays the same data (lateral flexion, flexion-extension, and rotation values) simultaneously, allowing test subjects to clearly see changes in neck movement angles. During the neck mobility test, the test subject first keeps their torso and head perpendicular to the ground, performing a "zero-position setting." In subsequent tests, the test subject must keep their torso and shoulders stationary. The test subject completes one cycle of neck flexion-extension, rotation, and lateral flexion, obtaining the maximum and minimum values ​​for each, reflecting the range of neck motion. Changes in neck movement angles can be recorded, exported, and analyzed to comprehensively assess the overall neck mobility status.

[0029] The above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also fall within the scope of the present invention, and the patent protection scope of the present invention should be defined by the claims.

Claims

1. A cervical spine mobility acquisition system based on a smartphone and a virtual reality headset, characterized in that: This includes a virtual reality headset (VR headset), which holds a smartphone. It acquires orientation sensor data through the Android system's sensor API and converts it into cervical spine mobility data. It uses the extreme point symmetric mode decomposition (ESMD) method to extract the optimal adaptive global average of the cervical spine mobility data and calculates the cervical spine mobility, enabling rapid and convenient continuous measurement of cervical spine mobility. The smartphone display side is kept relatively parallel to the human face, and the change in neck angle is equivalent to the change in phone angle. That is, the change in longitudinal tilt angle corresponds to lateral flexion, the change in transverse tilt angle corresponds to neck flexion and extension, and the change in azimuth angle corresponds to neck rotation. The cervical spine mobility is displayed simultaneously on the left and right screens of the VR headset, showing the lateral flexion, extension, and rotation values ​​of the neck. Users can directly see the current changes in cervical spine mobility. The VR headset also allows users to directly see the current human neck movement angle values, record a complete set of neck flexion, extension, rotation, and lateral flexion movement data, process the data to obtain the maximum and minimum values ​​of flexion, extension, rotation, and lateral flexion, reflect the range of neck movement, and comprehensively evaluate the human neck movement status. The pole-symmetric mode decomposition (ESMD) method was used to extract the trend term from the cervical spine mobility data. Based on the characteristics of the cervical spine mobility data, the maximum number of screening times and the number of remaining poles of the ESMD method were set to remove extreme measurement data of cervical spine mobility. The results were then statistically analyzed.

2. The system according to claim 1, characterized in that: The smartphone has a built-in gravity acceleration sensor and a geomagnetic field sensor. Its orientation sensing data is calculated using the accelerometer value and the geomagnetic field sensor value. By initializing the accelerometer sensor and the geomagnetic field sensor, the orientation sensing data of the smartphone is obtained, and then the changes in the phone's rotation angle, namely the tilt angle, pitch angle and azimuth angle, are obtained.

3. The system according to claim 1, characterized in that: The Bluetooth remote control is used to start and stop the human neck movement angle test. At the end of the test, the timestamp and cervical spine movement data are recorded.

4. The system according to claim 1, characterized in that: Before starting the human neck movement angle test, the human torso and head are perpendicular to the ground, and the torso and shoulders are kept still. The "zero position setting" is adjusted as the initial position, which is used as a reference for subsequent tests.

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