Dynamic monitoring system and monitoring method for patella motion trail during knee joint flexion

Abstract

The invention discloses a dynamic monitoring system and monitoring method for a patella motion trail during knee joint flexion, and the system comprises a flexible carrier, a data processor, and a plurality of pressure sensors which are uniformly distributed at one side of the flexible carrier. The flexible carrier is used for being attached to or bound to the knee joint, the side, provided with the pressure sensors, of the flexible carrier is attached to the knee joint, and the multiple pressure sensors are electrically connected with the data processor; therefore, the flexible carrier on which the pressure sensors are uniformly distributed can be worn on the knee joint, and when the knee joint moves from an upright state to a knee bending state, the plurality of pressure sensors can monitor pressure data values at the moment; and the data processor is used for calculating pressure data values monitored by the plurality of pressure sensors so as to obtain patella motion trail data at the knee joint.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sports biomechanics, and particularly relates to a patellar motion trajectory dynamic monitoring system and method during knee flexion. BACKGROUND

[0002] The patella slides up and down along the femoral trochlear groove during knee flexion and extension, and abnormal patellar motion trajectory is an important biomechanical feature of various knee diseases (such as patellofemoral pain, patellar subluxation, and poor mechanical recovery after anterior cruciate ligament surgery). At present, the measurement of the patellar motion trajectory mainly relies on MRI and biplane X-ray. These methods are not only high in cost and strong in dependence on site and personnel, but also cannot be used for dynamic and portable daily monitoring. At present, there is no solution with wearability, mobility and continuous monitoring of the patellar trajectory.

[0003] During the process of squatting, the knee joint gradually flexes from near the extension position (0°) to 90°, and the patella, as the force transmission structure of the knee extensor group, presents the following typical motion characteristics in the process: (1) vertical downward sliding: the patella slides downward along the femoral trochlear groove, and the motion amplitude gradually increases with the increase of the knee flexion angle. (2) slight medial and lateral deviation: especially in people with muscle imbalance or structural abnormalities, the patella may deviate outward or inward, resulting in an asymmetric trajectory. (3) rotation tilt: the rotation or tilt of the patella around the vertical axis is more obvious when the knee flexion angle exceeds 60°.

[0004] During the flexion and extension of the knee joint, the patella is located at the front of the knee joint and is the bony landmark that first contacts the anterior structure. Especially during knee flexion, the patella slides downward along the femoral trochlear groove, and the changes in its position, posture and trajectory will produce clear pressure change transmission to the outside world through the subcutaneous tissue. SUMMARY

[0005] To solve the above technical problems, one of the purposes of the present application is to provide a knee joint flexion patellar motion trajectory dynamic monitoring system which is simple in structure and convenient to wear.

[0006] To achieve the above purpose, the technical scheme of the present application is as follows: a knee joint flexion patellar motion trajectory dynamic monitoring system, comprising a flexible carrier, a data processor and a plurality of pressure sensors evenly distributed on one side of the flexible carrier, the flexible carrier is used to be attached or bound at the knee joint, and the side of the flexible carrier provided with the pressure sensors is used to be attached to the knee joint, and the plurality of pressure sensors are electrically connected with the data processor.

[0007] The beneficial effects of the above technical solution are that the flexible carrier with the pressure sensors uniformly distributed can be worn at the knee joint, and when the knee joint moves from the upright state to the bent state, the plurality of pressure sensors can monitor the pressure data values, and the data processor calculates the pressure data values monitored by the plurality of pressure sensors to obtain the patella movement trajectory data at the knee joint.

[0008] In the above technical solution, the flexible carrier is rectangular, and the plurality of pressure sensors are distributed in a matrix on one side of the flexible carrier.

[0009] The beneficial effects of the above technical solution are that the pressure sensors are distributed in a matrix on the corresponding side of the flexible carrier, so as to facilitate the calibration of the coordinates of each pressure sensor.

[0010] In the above technical solution, the spacing between the two adjacent pressure sensors in the same row is less than or equal to 3mm.

[0011] The beneficial effects of the above technical solution are that the pressure sensors in the same row on the flexible carrier are densely distributed, which is beneficial to improve the monitoring accuracy.

[0012] In the above technical solution, the spacing between the two adjacent pressure sensors in the same column is less than or equal to 3mm.

[0013] The beneficial effects of the above technical solution are that the pressure sensors in the same column on the flexible carrier are densely distributed, which is beneficial to improve the monitoring accuracy.

[0014] In the above technical solution, the spacing between the two adjacent pressure sensors in the same row is consistent with the spacing between the two adjacent pressure sensors in the same column.

[0015] The beneficial effects of the above technical solution are that the row and column spacings of the pressure sensors on the flexible carrier are consistent, which is more beneficial to calibrate the coordinates of the pressure sensors.

[0016] In the above technical solution, the flexible carrier is a silica gel sheet, a latex sheet, or a rubber sheet.

[0017] The beneficial effects of the above technical solution are that the flexible carrier is comfortable to wear.

[0018] In the above technical solution, the two sides of the flexible carrier are provided with straps.

[0019] The beneficial effects of the above technical solution are that the flexible carrier is worn at the knee joint in a binding manner.

[0020] The technical scheme further comprises a Bluetooth module arranged on the side of the flexible carrier away from the pressure sensor, and the Bluetooth module is used for being communicatively connected with the data processor.

[0021] The technical scheme has the beneficial effect that the data monitored by the pressure sensor can be wirelessly transmitted to the data processor for data processing.

[0022] The data processor is a smart phone or a computer.

[0023] The technical scheme has the beneficial effect of simple structure and good processing performance.

[0024] The second object of the present application is to provide a monitoring method for calculating the patellar trajectory when the knee joint is flexed.

[0025] To achieve the above object, the technical scheme of the present application is as follows: a monitoring method for the patellar trajectory dynamic monitoring system for the knee joint when the knee joint is flexed, comprising the following steps:

[0026] comprising the following steps:

[0027] Step 1: wearing the flexible carrier (1) at the knee joint;

[0028] Step 2: recording the basic pressure value of each pressure sensor (3) in the state of straightening the knee joint;

[0029] Step 3: completing the flexion action, collecting the flexion pressure value of each pressure sensor (3), calculating the difference between the flexion pressure value and the basic pressure value, and obtaining the pressure change value Pi;

[0030] Step 4: calculating the overall pressure centroid coordinates (X c ,Y c ) of each pressure sensor (3) and the pressure change value Pi;

[0031] wherein, The trajectory formed by the change of the centroid coordinates over time is the relative motion trajectory estimation curve of the patella.

[0032] The technical scheme has the beneficial effect that when the knee joint is flexed, the trajectory change of the patella can be indirectly obtained by detecting the dynamic change data of the pressure distribution through the multiple pressure sensors on the flexible carrier. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a schematic view of the patellar trajectory dynamic monitoring system for the knee joint when the knee joint is flexed according to Embodiment 1 of the present application;

[0034] Figure 2 is a schematic diagram of the flexible carrier in Example 1 of the present invention, facing away from the pressure sensor;

[0035] Figure 3 This is a schematic diagram of the wearing portion being worn at the knee joint in Example 1 of the present invention;

[0036] Figure 4 Schematic diagram of the trajectory of patella movement when the knee joint is bent in Example 2 of the present invention.

[0037] In the figure: 1 flexible carrier; 2 data processor; 3 pressure sensor; 4 strap; 5 Bluetooth module; 6 power module; 7 control module. DETAILED DESCRIPTION

[0038] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention. The following paragraphs describe the present invention in more detail by way of example with reference to the accompanying drawings. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the drawings are all in a very simplified form and are not in exact proportions. They are only used to facilitate and clearly illustrate the purpose of the embodiments of the present invention.

[0039] Example 1

[0040] like Figure 1 and Figure 3 As shown, this embodiment provides a dynamic monitoring system for the movement trajectory of the patella during knee flexion, including a flexible carrier 1, a data processor 2 and a plurality of pressure sensors 3 evenly distributed on one side of the flexible carrier 1, the flexible carrier 1 is used to be attached or tied to the knee joint, and the side of the flexible carrier 1 provided with the pressure sensors 3 is used to fit with the knee joint, and the plurality of pressure sensors 3 are electrically connected to the data processor 2, so that the flexible carrier evenly distributed with the pressure sensors can be worn at the knee joint, and when the knee joint moves from an upright state to a flexed state, the plurality of pressure sensors can monitor the pressure data values, and the data processor calculates the pressure data values ​​monitored by the plurality of pressure sensors to obtain the patella movement trajectory data at the knee joint.

[0041] In the above technical solution, the flexible carrier 1 is rectangular, and the multiple pressure sensors 3 are distributed in a matrix on one side of the flexible carrier 1, so that the pressure sensors are distributed in a matrix on the corresponding sides of the flexible carrier, so as to facilitate the calibration of the coordinates of each pressure sensor.

[0042] In the above technical solution, the distance between two adjacent pressure sensors 3 in the same row is less than or equal to 3 mm (can be 1 mm, 2 mm or 3 mm), so that the pressure sensors in the same row on the flexible carrier are distributed more densely, which is conducive to improving the monitoring accuracy.

[0043] In the above technical solution, the distance between two adjacent pressure sensors 3 in the same column is less than or equal to 3 mm (can be 1 mm, 2 mm or 3 mm), so that the pressure sensors in the same column on the flexible carrier are distributed more densely, which is conducive to improving the monitoring accuracy.

[0044] In the above technical solution, the spacing between two adjacent pressure sensors 3 in the same row is consistent with the spacing between two adjacent pressure sensors 3 in the same column, so that the row and column spacing of the pressure sensors on the flexible carrier is consistent, which is more conducive to calibrating the coordinates of the pressure sensors.

[0045] The flexible carrier 1 in the above technical solution is a silicone sheet, a latex sheet or a rubber sheet, which makes the flexible carrier more comfortable to wear.

[0046] In the above technical solution, the flexible carrier 1 is provided with straps 4 on both sides, so that the flexible carrier is worn at the knee joint in a binding manner when worn.

[0047] The above technical solution also includes a Bluetooth module 5 arranged on the side of the flexible carrier 1 away from the pressure sensor 3, and the Bluetooth module 5 is used to communicate with the data processor 2, so that the data monitored by the pressure sensor can be transmitted wirelessly to the data processor for data processing.

[0048] The data processor 2 in the above technical solution is a smart phone or a computer, which has a simple structure and good processing performance.

[0049] like Figure 2 As shown, in this embodiment, a power module and a control module may be disposed on the side of the flexible carrier facing away from the pressure sensor. The power module may be a button battery pack, and the control module may be a microcontroller chip, such as an STM32 series microcontroller chip. In this embodiment, the multiple pressure sensors, Bluetooth modules, and power modules are all electrically connected to the control module. A power switch may be disposed at the electrical connection between the power module and the control module.

[0050] The dynamic monitoring system for the patellar movement trajectory during knee flexion described in this embodiment includes a wearable part and a data processing part. The wearable part includes a flexible carrier and a pressure sensor, a Bluetooth module, a power module and a control module arranged thereon, and the data processing part is a data processor (the data processor can be installed with a corresponding APP program to process the data monitored by the pressure sensor).

[0051] Example 2

[0052] like Figure 4 As shown, this embodiment provides a monitoring method of the patellar motion trajectory dynamic monitoring system during knee flexion as described above, comprising the following steps:

[0053] Step 1: Wear the flexible carrier 1 on the knee joint;

[0054] Step 2: Record the basic pressure value of each pressure sensor 3 when the knee joint is extended;

[0055] Step 3: Complete the knee flexion movement, collect the knee flexion pressure value of each pressure sensor 3, calculate the difference between the knee flexion pressure value and the basic pressure value, and thus obtain the pressure change value Pi;

[0056] Step 4: Calculate the overall pressure centroid coordinates (Xc, Yc) by weighting the position (xi, yi) of each pressure sensor 3 and the pressure change value Pi.

[0057] in,

[0058] The trajectory formed by the change of the centroid coordinates over time is the estimated curve of the relative motion trajectory of the patella. In this way, when the knee joint is flexed, the trajectory change of the patella can be indirectly obtained by detecting the dynamic change data of the pressure distribution through multiple pressure sensors on the flexible carrier (where i is the index number of a single sensor unit in the pressure sensor array, c itself is meaningless, Pi represents the pressure value detected by the sensor unit in real time, (xi, yi) are the position coordinates of the sensor unit in the plane coordinate system of the sensor array, and (Xc, Yc) represent the overall pressure centroid coordinates calculated based on the weighted pressure of all sensor units).

[0059] This embodiment deeply integrates a flexible two-dimensional pressure sensor array with a patellar motion trajectory monitoring algorithm to form a new, non-invasive, low-cost trajectory reconstruction platform. Its technological innovations are reflected in:

[0060] The positioning target is clearly focused on "patellar trajectory": different from general knee motion monitoring devices, it focuses on "reconstructing the trajectory of the patella in the femoral trochlear groove". The target is clearly focused and its function targets the clinical pain points of current sports injury mechanism assessment.

[0061] The high-density pressure sensor array covers the possible movement area of ​​the patella: the use of a large-area flexible matrix sensing area rather than a point or ring layout greatly improves the tolerance to patellar deviation and trajectory analysis accuracy.

[0062] Dynamic pressure center estimation and trajectory generation algorithm innovation: through pressure center calculation, combined with dynamic correction of knee angle, output time continuous, spatial accurate two-dimensional patellar motion trajectory.

[0063] The above is only the preferred embodiment of the present application, and does not limit the present application in any form; those skilled in the art can easily implement the present application according to the drawings shown in the specification and the above description; however, those skilled in the art can make some changes, modifications and equivalent changes within the scope of the technical solutions of the present application by using the above disclosed technical content, which are equivalent embodiments of the present application; at the same time, any equivalent changes, modifications and evolution of the above embodiments according to the essential technology of the present application are still within the protection scope of the technical solutions of the present application.

Claims

1. A dynamic monitoring system for patellar motion trajectory during knee flexion, characterized in that: The invention comprises a flexible carrier (1), a data processor (2), and a plurality of pressure sensors (3) uniformly distributed on one side of the flexible carrier (1); the flexible carrier (1) is used to be attached to or tied to the knee joint, and the side of the flexible carrier (1) provided with the pressure sensors (3) is used to be attached to the knee joint; the plurality of pressure sensors (3) are all electrically connected to the data processor (2).

2. The system for dynamic monitoring of patellar motion trajectory during knee flexion according to claim 1, characterized in that: The flexible carrier (1) is rectangular, and the plurality of pressure sensors (3) are distributed in a matrix on one side of the flexible carrier (1).

3. The system for dynamically monitoring the movement trajectory of the patella during knee flexion according to claim 2, characterized in that: The distance between two adjacent pressure sensors (3) in the same row is less than or equal to 3 mm.

4. The system for dynamically monitoring the patellar motion trajectory during knee flexion according to claim 2, characterized in that: The distance between two adjacent pressure sensors (3) in the same row is less than or equal to 3 mm.

5. The system for dynamically monitoring the movement trajectory of the patella during knee flexion according to claim 2, characterized in that: The spacing between two adjacent pressure sensors (3) in the same row is consistent with the spacing between two adjacent pressure sensors (3) in the same column.

6. The system for dynamically monitoring the movement trajectory of the patella during knee flexion according to claim 1, characterized in that: The flexible carrier (1) is a silicone sheet, a latex sheet or a rubber sheet.

7. The system for dynamically monitoring the movement trajectory of the patella during knee flexion according to claim 1, characterized in that: Binding straps (4) are provided on both sides of the flexible carrier (1).

8. The system for dynamically monitoring the movement trajectory of the patella during knee flexion according to any one of claims 1 to 7, characterized in that: It also includes a Bluetooth module (5) arranged on a side of the flexible carrier (1) away from the pressure sensor (3), and the Bluetooth module (5) is used for communication connection with the data processor (2).

9. The system for dynamically monitoring the movement trajectory of the patella during knee flexion according to any one of claims 1 to 7, characterized in that: The data processor (2) is a smart phone or a computer.

10. A monitoring method of a patellar motion trajectory dynamic monitoring system during knee flexion according to any one of claims 1 to 9, characterized in that: The steps include: Step 1: Wear the flexible carrier (1) on the knee joint; Step 2: Record the basic pressure value of each pressure sensor (3) when the knee joint is extended; Step 3: Complete the knee flexion movement, collect the knee flexion pressure value of each pressure sensor (3), calculate the difference between the knee flexion pressure value and the basic pressure value, and thus obtain the pressure change value Pi; Step 4: The position (xi, yi) of each pressure sensor (3) and the pressure change value Pi are weighted to obtain the overall pressure centroid coordinates (X c ,Y c ), in, The trajectory formed by the change of the center of mass coordinates over time is the relative motion trajectory estimation curve of the patella.

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