CN216675735U - A system for measuring the angle of the lower limb force line - Google Patents

Abstract

The utility model relates to the field of lower limb force line detection in orthopaedic clinics, and discloses a lower limb force line angle measurement system, comprising a knee joint fixing frame, an ankle joint fixing frame, a data processing center and a display module; the knee joint fixing frame comprises a knee joint fixing frame The joint elastic fixing body is provided with a sensing unit on both sides of the knee joint elastic fixing body; the ankle joint fixing frame includes an ankle joint elastic fixing body, and a sensing unit is respectively arranged on both sides of the ankle joint elastic fixing body; four The sensing units are respectively connected with the data processing center, and the data processing center is used for determining the lower limb force line and the included angle of the lower limb force line; the display module is connected with the data processing center for displaying the lower limb force line. It solves the problems that the existing device has complicated operation steps, needs to invasively fix the sensor to the bone, and is not suitable for the real-time determination of the force line during the operation.

Description

A system for measuring the angle of the lower limb force line

technical field

The utility model relates to the field of detection of lower limb force line in orthopaedic clinic, and discloses a measurement system for the angle of lower limb force line.

Background technique

Knee osteoarthritis is a chronic joint disease characterized by degeneration and loss of knee cartilage and bone regeneration of the joint edge and subchondral bone. The clinical manifestations are mainly knee joint pain, deformity, and dysfunction. It is treated by clinical surgery such as artificial knee replacement and high tibial osteotomy.

Whether it is the planning and implementation of knee replacement or high tibial osteotomy, as well as the evaluation of the later surgical effect, accurate judgment of lower limb alignment is an essential process. The lower limb force line refers to the line connecting the center point of the femoral head to the center point of the ankle joint. The normal force line of the lower limb should pass through the center point of the knee joint. During the operation, it is often necessary to constantly locate the lower limb force line of the human body, so as to adjust the varus angle of the knee joint of the human body. In the prior art, the surgeon usually holds both ends of the metal force line measuring rod, so that one end of the force line measuring member is aligned with the center point of the femoral head, and the other end is aligned with the center point of the ankle joint, and then the human body is observed through X-ray fluoroscopy. Whether the lower limb force line passes through the center point of the knee joint, so as to judge whether the angle of joint replacement or osteotomy is appropriate.

However, the measurement and positioning method of the doctor's hand-held force line measuring piece is affected by human factors such as the doctor's hand shaking, which may reduce the accuracy of the measurement. Using a fixed device to fix the force line measuring rod on the human body or operating table can improve the measurement accuracy, but intraoperative real-time fluoroscopy greatly increases the radiation dose received by doctors and patients, which affects their health.

In order to solve the above problems, the patent 201910599596 discloses a lower limb force line angle assessment and osteotomy device based on acceleration and gyroscope. The lower limb movement is monitored by the navigation device fixed on the bone, and the direction indicated by the navigation device is converted into the lower limb force. The angle of the line is further determined by the laser pointer to determine the angle of the target osteotomy. This kind of utility model solves the radiation dose problem caused by the problem of holding a metal measuring rod or a fixing rod to a certain extent, but it needs to fix the sensor to the bone with a steel nail, which can only be used in surgery and is invasive. , this method requires multiple measurements to complete the angle of the lower limb force line, the steps are cumbersome, and the operation time is increased. Crucially, such methods cannot precisely determine the center point location of the knee and ankle joints. Patent 201910884469 discloses a method of using CT image data to build a lower extremity skeletal model, and reconstructing a 3D model to determine the lower extremity force line. This method may be more accurate, but the operation process is cumbersome, requires resources such as CT, and is not suitable for Intraoperative real-time determination of the force line.

Utility model content

The purpose of the utility model is to provide a measurement system for the angle of the force line of the lower limb, which solves the problems that the existing device has complicated operation steps, needs to invasively fix the sensor to the bone, and is not suitable for the real-time determination of the force line during the operation.

The utility model is realized through the following technical solutions:

A measuring system for the angle of the lower limb line of force, comprising a knee joint fixation frame, an ankle joint fixation frame, a data processing center and a display module;

The knee joint fixing frame includes a knee joint elastic fixing body, one side of the knee joint elastic fixing body is provided with a knee joint inner sensing unit, and the other side is provided with a knee joint outer sensing unit;

The ankle joint fixing frame includes an ankle joint elastic fixing body, one side of the ankle joint elastic fixing body is provided with an ankle joint inner side sensing unit, and the other side is provided with an ankle joint outer side sensing unit;

The knee joint medial sensing unit, the knee lateral sensing unit, the ankle joint medial sensing unit and the ankle lateral sensing unit are respectively connected with the data processing center, and the data processing center is used to determine the lower limb force line and the included angle of the lower limb force line ;

The display module is connected with the data processing center for displaying the lower limb force line.

Further, the knee joint fixing frame also includes a knee joint inner body guard and a knee joint outer body guard, the knee joint inner body guard is connected to one side of the knee joint elastic fixing body, and the knee joint outer body guard is connected to the other side of the knee joint elastic fixing body. one side;

The knee joint inner side sensing unit is fixed on the knee joint inner protective body, and the knee joint outer side sensing unit is fixed on the knee joint outer protective body.

Further, the ankle joint fixing frame also includes an ankle joint inner protective body and an ankle joint outer protective body, the ankle joint inner protective body is connected to one side of the ankle joint elastic fixing body, and the ankle joint outer protective body is connected to the other side of the ankle joint elastic fixing body. one side;

The inner ankle joint sensing unit is fixed on the ankle joint inner protective body, and the ankle joint outer sensing unit is fixed on the ankle joint outer protective body.

Further, the sensing unit inside the knee joint, the sensing unit outside the knee joint, the sensing unit inside the ankle joint and the sensing unit outside the ankle joint all have built-in wireless communication modules, and the wireless communication modules are connected to the data processing center.

Further, the wireless communication module adopts an SPI wireless module.

Further, the models of the knee joint medial sensing unit, the knee joint lateral sensing unit, the ankle joint medial sensing unit and the ankle lateral sensing unit are MPU9250.

Compared with the prior art, the utility model has the following beneficial technical effects:

The utility model discloses a measuring system for the angle of the lower limb line of force, which comprises a knee joint fixing frame, an ankle joint fixing frame and a data processing center. There are sensing units, 4 sensing units are connected to the data processing center, and the data processing center performs fusion calculation on the received sensing unit data to obtain the femoral acetabular fossa-knee joint center line and the acetabular fossa-ankle The joint center is connected to obtain the angle and offset degree of the lower limb force line; the knee joint is fixed to the human knee joint, and the ankle joint is fixed to the human ankle joint. The positioning method improves the accuracy of the positioning of the lower limb force line, and avoids the problem that medical personnel need to bear high doses of X-ray radiation in the hand-held force line measuring piece; the lower limb force line angle measurement system of the present invention adopts paired The sensor is fixed on the knee joint and ankle joint, which facilitates accurate measurement of the center point of the human femoral head, the center point of the knee joint and the center point of the ankle joint during the movement process, which solves the problem that the existing equipment cannot accurately determine the center point of the knee joint and the ankle joint. The small sensing unit performs wireless data transmission, which eliminates the traditional complex measurement devices in the clinic, and is simple to operate and easy to use; the sensing unit is fixed on the outside of the joint, and the sensor does not need to be fixed to the bone by surgery, which solves the invasive problem of the previous device. ; The data processing center can receive the motion data of each positioning device in real time, calculate the required target joint center, and then calculate the real-time lower limb force line and lower limb force line offset angle, and obtain the angle that needs to be corrected by surgery. Advantages of real-time monitoring of lower extremity alignment during and after surgery.

Further, the devices for fixing the sensors are respectively the inner and outer protective bodies of the knee joint and the ankle joint, and the inner and outer protective bodies of the knee joint and the ankle joint are fixed to the lower limb through the bony protrusions of the knee joint and the ankle joint. The elastic fixing body of the fixing bracket can adjust the size of the bracket through manual control, so that the bracket can freely match the size of the lower limbs of different patients, and has the advantages of easy wearing, simple operation, and practical convenience.

Description of drawings

Fig. 1 is the structural representation of the measuring system of the lower limb force line angle of the present invention;

Fig. 2 is the schematic diagram of the knee joint fixing frame in the measuring system of the lower limb force line angle of the present invention;

Fig. 3 is the side view of Fig. 2;

Fig. 4 is the schematic diagram of the ankle joint fixing frame in the measuring system of the lower limb force line angle of the present invention;

Fig. 5 is the side view of Fig. 4;

6 is a schematic diagram of the angle of the lower limb force line of the present invention;

7 is a schematic diagram of the detection of the angle of the force line in the lower limb shaking process of the present invention;

FIG. 8 is a schematic diagram of the principle of the calculation flow of the lower limb force line of the present invention.

Among them: 1 is the knee joint elastic fixing body, 2 is the ankle joint elastic fixing body, 3 is the knee joint inner side sensing unit, 4 is the knee joint outer side sensing unit, 5 is the ankle joint inner side sensing unit, 6 is the outer side of the ankle joint Sensing unit, 7 is the spring, 8 is the knee joint inner protector, 9 is the knee joint outer protector, 10 is the center of the femoral head, 11 is the knee joint center, 12 is the ankle joint center; 13 is the ankle joint inner protector, 14 is the ankle joint outer protector.

Detailed ways

The present utility model will be further described in detail below with reference to specific embodiments, which are to explain rather than limit the present utility model.

As shown in FIG. 1 , the utility model discloses a measurement system for the angle of the lower limb force line, which includes a sensing unit, a knee joint fixing frame, an ankle joint fixing frame, a data processing center and a display module.

The sensing unit is used to monitor the motion of the thighs, calves and joints of the lower limbs, output raw data such as acceleration and angle, and output the data to the data processing center through the wireless transmission module integrated in the sensing unit;

The knee joint fixing frame includes a knee joint semi-wrapped elastic bracket with its own elasticity, namely the knee joint elastic fixing body 1, which is used to accurately fix the two sensing units at high positions on both sides of the knee joint. When the medical staff shakes the lower limbs, they can locate the center of the femoral head 10 and the center of the knee joint 11 by fusing the data of the two sensing units;

The ankle joint fixation frame includes an ankle joint semi-wrapped elastic support with its own elasticity, namely the ankle joint elastic fixation body 2, which is used to accurately fix the two sensing units at high positions on both sides of the joint. When the medical staff shakes the lower limbs, they can locate the center of the femoral head 10 and the center of the ankle joint 12 by fusing the data of the two sensing units;

The data processing center wirelessly receives the data of the sensing unit and performs fusion calculation to obtain the connection between the femoral acetabular fossa and the center of the knee joint, and the connection between the acetabular fossa and the center of the ankle joint, and calculate the angle and offset degree of the lower limb force line;

The display interface is used to display the lower limb force line in real time, which is convenient for real-time adjustment during surgery.

As shown in Fig. 2-3, the knee joint fixing frame includes a knee joint elastic fixing body 1, and a knee joint inner side sensing unit 3 is arranged on one side of the knee joint elastic fixing body 1, and a knee joint outer side sensing unit 3 is arranged on the other side. Unit 4; the knee joint fixing frame also includes a knee joint inner body 8 and a knee joint outer body 9, the knee joint inner body 8 is connected to one side of the knee joint elastically fixed body 1, and the knee joint outer body 9 is connected to the knee joint. The other side of the body 1 is fixed elastically by the joint; the inner knee joint sensing unit 3 is fixed on the knee joint inner body 8 , and the knee joint outer sensing unit 4 is fixed on the knee joint outer body 9 .

As shown in Figures 4-5, the ankle joint fixation frame includes an ankle joint elastic fixing body 2, and an ankle joint inner side sensing unit 5 is arranged on one side of the ankle joint elastic fixing body 2, and an ankle joint outer side sensing unit 5 is arranged on the other side. Unit 6. The ankle joint fixation frame also includes an inner ankle joint protector 13 and an outer ankle joint protector 14, the ankle joint inner protector 13 is connected to one side of the ankle joint elastically fixed body 2, and the ankle joint outer protector 14 is connected to the ankle joint elastically fixed body. On the other side of the body 2; the inner ankle joint sensing unit 5 is fixed on the ankle joint inner shield 13, and the ankle joint outer sensing unit 6 is fixed on the ankle joint outer shield 14.

As shown in FIGS. 3 and 5 , the elastic fixing body 1 of the knee joint and the elastic fixing body 2 of the ankle joint are provided with springs 7 to ensure that the lengths of the two fixing bodies can be adjusted according to the thickness of the legs of different patients.

The sensing unit is fixed on the knee joint fixing frame and the ankle joint fixing frame, the knee joint fixing frame is clamped at the knee joint, the sensing unit is fixed on the inner and outer high points of the knee joint and the ankle joint, and the lower limb of the patient is accelerated from rest by holding the patient. Movement, the sensing unit collects joint motion data, transmits the data to the processing center through the wireless transmission module, determines and calculates the angle between the two connecting lines, and determines the lower limb force line.

When measuring the alignment of the lower extremity, the patient's knee joint is in a straight state. The tester holds the patient's lower extremity and accelerates the motion from rest. The four sensing units collect the joint motion data and wirelessly transmit it to the data processing center to determine the femoral acetabular fossa-knee joint center respectively. The connection line, the acetabular fossa-ankle center connection line, calculate the angle between the two connection lines, and evaluate the force line state. It can be used for pre- and post-operative evaluation of orthopaedic surgery such as joint replacement or intraoperative correction of the force line. The system uses a small sensing unit for wireless data transmission, which eliminates the traditional complex measurement devices in the clinic, and is simple to operate and easy to use.

By arranging sensors in pairs on the knee joint and ankle joint respectively, the center point of the joint and the center point of the femoroacetabular fossa are accurately detected, and the line between the center of the femoral acetabular fossa and the knee joint and the line between the acetabular fossa and the center of the ankle joint are calculated. , calculate the angle and offset degree of lower limb line of force; multi-point arrangement of sensing units avoids the problem that the sensor must be directly fixed to the bone.

The knee joint medial sensing unit 3 and the knee joint lateral sensing unit 4 send the collected knee joint motion data to the data processing center, and the data processing center calculates the knee joint center 11; the ankle joint medial sensing unit 5 and the ankle joint lateral The sensing unit 6 sends the collected ankle joint motion data to the data processing center, and the data processing center calculates the ankle joint center 12 .

The specific process for the data processing center to determine the knee joint center 11 and the ankle joint center 12 is as follows:

First calculate the rotation radius of the 4 sensors;

Then a unified coordinate system is established with the rotation center as the origin, and the position of each sensor in this coordinate system is determined. The knee joint center 11 is obtained according to the positions of the knee joint inner sensing unit 3 and the knee joint outer sensing unit 4 under the coordinates; according to the positions of the ankle joint inner sensing unit 5 and the ankle outer sensing unit 6 under the coordinates Get the ankle center 12.

As shown in Figure 6-8, the line connecting the center of the knee joint 11 to the center of the femoral head 10 is the line connecting the femoral acetabular fossa and the center of the ankle joint, which is recorded as the first connecting line, and the distance L1 of the first connecting line is calculated; The line connecting the joint center 12 to the center 10 of the femoral head is the line connecting the acetabular fossa and the center of the ankle joint, which is denoted as the second connecting line, and the distance L2 of the second connecting line is calculated.

Projecting the knee joint center 11 onto the second connecting line, the femoral head center 10, the projection point of the knee joint center 11, and the ankle joint center 12 can determine a triangle, and calculate the distance L3 from the projection point of the knee joint center 11 to the second connecting line .

Calculate the angle β between the first connecting line and the second connecting line according to L1 and L3.

Claims (6)

1. A measuring system for lower limb force line angles is characterized by comprising a knee joint fixing frame, an ankle joint fixing frame, a data processing center and a display module;

the knee joint fixing frame comprises a knee joint elastic fixing body (1), wherein a knee joint inner side sensing unit (3) is arranged on one side of the knee joint elastic fixing body (1), and a knee joint outer side sensing unit (4) is arranged on the other side of the knee joint elastic fixing body;

the ankle joint fixing frame comprises an ankle joint elastic fixing body (2), wherein an ankle joint inner side sensing unit (5) is arranged on one side of the ankle joint elastic fixing body (2), and an ankle joint outer side sensing unit (6) is arranged on the other side of the ankle joint elastic fixing body;

the knee joint inner side sensing unit (3), the knee joint outer side sensing unit (4), the ankle joint inner side sensing unit (5) and the ankle joint outer side sensing unit (6) are respectively connected with a data processing center, and the data processing center is used for determining a lower limb force line and an included angle of the lower limb force line;

the display module is connected with the data processing center and used for displaying the lower limb force line.

2. The system for measuring the force line angle of the lower limbs according to claim 1, wherein the knee joint fixing frame further comprises a knee joint inner protecting body (8) and a knee joint outer protecting body (9), the knee joint inner protecting body (8) is connected to one side of the knee joint elastic fixing body (1), and the knee joint outer protecting body (9) is connected to the other side of the knee joint elastic fixing body (1);

the knee joint inner side sensing unit (3) is fixed on the knee joint inner protective body (8), and the knee joint outer side sensing unit (4) is fixed on the knee joint outer protective body (9).

3. The system for measuring the force line angle of the lower limbs according to claim 1, wherein the ankle joint fixing frame further comprises an ankle joint inner protecting body (13) and an ankle joint outer protecting body (14), the ankle joint inner protecting body (13) is connected to one side of the ankle joint elastic fixing body (2), and the ankle joint outer protecting body (14) is connected to the other side of the ankle joint elastic fixing body (2);

the ankle joint inner side sensing unit (5) is fixed on the ankle joint inner protecting body (13), and the ankle joint outer side sensing unit (6) is fixed on the ankle joint outer protecting body (14).

4. The system for measuring the force line angle of the lower limbs according to claim 1, wherein the knee joint inner side sensing unit (3), the knee joint outer side sensing unit (4), the ankle joint inner side sensing unit (5) and the ankle joint outer side sensing unit (6) are all internally provided with wireless communication modules, and the wireless communication modules are connected with the data processing center.

5. The system for measuring the angle of the lower limb line of force of claim 4, wherein the wireless communication module is an SPI wireless module.

6. The system for measuring the force line angle of the lower limbs according to claim 1, wherein the type of the knee joint inner side sensing unit (3), the knee joint outer side sensing unit (4), the ankle joint inner side sensing unit (5) and the ankle joint outer side sensing unit (6) is MPU 9250.

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