METHOD AND SYSTEM FOR ACQUIRING ATTITUDE OF ACETABULUM AND FEMORAL HEAD IN REAL TIME DURING HIP JOINT REPLACEMENT PROCEDURE

• US 20150289890A1
• Filed: 10/08/2012
• Published: 10/15/2015
• Est. Priority Date: 05/14/2012
• Status: Active Grant

• Current Assignee: Tsinghua University
• Original Assignee: Tsinghua University
• Inventors: Chen, Hong, Wang, Zhihua, Zhou, Yixin, Su, Shaojie, Sun, Tianjia, Gao, Jiyang, Jiang, Hanjun
• Granted Patent: US 10,034,779 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61F 2/3609 Femoral heads or necks; Connections of endoprosthetic heads or necks to endoprosthetic femoral shafts A61F2/3601 takes precedence
• CPC Class Codes: A61F 2/4657 Measuring instruments used for implanting artificial joints for surgical instruments A61B90/06
• CPC Class Codes: A61F 2/4684 Trial or dummy prostheses
• CPC Class Codes: A61F 2002/30668 Means for transferring electromagnetic energy to implants
• CPC Class Codes: A61F 2002/4666 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61F 2002/4668 for measuring angles

Abstract

A method and system for acquiring the attitudes of an acetabulum and a femoral head in real time during an artificial hip joint replacement procedure; during hip joint replacement, a pressure sensor and/or a touch sensor are disposed at each pressure point concerned for a femoral head prosthesis test mould, forming a sensor array (1); the sensor array (1) acquires the contact and stress conditions between the femoral head prosthesis test mould and the acetabulum, and sends out a signal; and a receiving terminal receives and displays the signal on a display module, and acquires the simulated attitudes of the acetabulum and the femoral head. The system comprises a sensor array (1), a necessary peripheral circuit, and a signal receiving and display device for receiving and displaying the signal sent by the peripheral circuit. The present invention can accurately simulate the presented attitude of the femoral head prosthesis during hip joint replacement procedure, so that a doctor can intuitively see the position and movement condition of the femoral head prosthesis during the procedure, thus improving the success rate and curative effect of the hip joint replacement procedure.

Claims

1. A method for acquiring relative pose in real time between an acetabulum and a femoral head in hip replacement, the method comprising:

a) disposing pressure sensors and/or touch sensors at pressure-concerning positions in the hip replacement on a femoral head trial whereby forming a sensor array;

b) acquiring signals of interactive contacts and forces between the femoral head trial and the acetabulum by the sensor array, and transmitting the signals wirelessly; and

c) receiving the signals by a wireless receiver and displaying the signals by a display module whereby simulating relative pose between the acetabulum and the femoral head in real time.

2. The method of claim 1, further comprising:

disposing an image sensor inside the femoral head trial which is configured to acquire position information of the femoral head trial and transmit the position information of the femoral head trial to the display module.

3. The method of claim 2, wherein patterns are previously designed on an inner side of the acetabulum;

and images of the patterns on the inner side of the acetabulum is acquired by the image sensor, whereby obtaining the position information of the femoral head trial.

4. A system for acquiring relative pose in real time between an acetabulum and a femoral head in hip replacement according to the method of claim 1, the system comprising:

a) the sensor array, the sensor array comprising a plurality of pressure sensors and/or touch sensors, the pressure sensors and/or the touch sensors being disposed on the concerned pressure points in the hip replacement on the femoral head trial;

b) a peripheral circuit, being configured to process and transmit the signals acquired by the sensor array; and

c) a signal receiving displaying device, being configured to receive and display signals transmitted from the external circuit.

5. The system of claim 4, wherein the sensor array further comprises an image sensor disposed inside the femoral head template.

6. The system of claim 4 or 5, wherein the peripheral circuit comprises:

a) a signal amplifier, being connected to an output of the sensor array and realizing amplification and analog-digital conversion of the signals from the sensors;

b) a first microprocessor, being connected to an output of the signal amplifier, controlling the sensor array and the signal amplifier operating normally, conducting parallel-series conversion on the digital signals of the sensors, and packing the digital signals; and

c) a first wireless transceiver, being connected to an output of the first microprocessor and sending out the packed data; and

the signal receiving displaying device comprises;

d) a second wireless transceiver for receiving the data transmitted from the first wireless transceiver;

e) a second microprocessor for receiving the data from the second wireless transceiver and processing the digital signals of the sensors into a form convenient for operators to observe; and

f) a display module, being connected to the second microprocessor for displaying the result of the second microprocessor.

7. The system of claim 4 or 5, wherein the external circuit comprises:

a) a signal amplification module, being connected to an output of the sensor array and realizing amplification and digital-analog conversion of the signals from the sensors; and

b) a first microprocessor, being connected to an output of the signal amplification module, controlling normal operation of the sensor array and the signal amplification module, conducting series/parallel processing on the digital signals of the sensors, and packing and transmitting the signals; and

the signal receiving displaying device comprises;

c) a second microprocessor for connecting to an signal output end of the first microprocessor and processing the digital signals of the sensors into a form convenient for observation of an operator; and

d) a display module, being connected to the second microprocessor for displaying a processing result of the second microprocessor.

8. The system of claim 4 or 5, wherein a permanent magnet can be added on the acetabulum, and a single-axis or multi-axis magnetometer is mounted in the femoral head trial, whereby measuring a relative angle between the acetabulum and the femoral head.

9. The system of claim 4 or 5, wherein

one end of the femoral head trial is a hemispherical shell;

and holes are distributed on the hemispherical shell of the femoral head trial for mounting pressure sensors or touch sensors and ground wires.

10. The system of claim 9, wherein distribution of the mounting holes on the hemispherical shell is as follows.

11. The system of claim 9, wherein

one of the pressure/touch sensors or touch sensors is disposed in the mounting hole on a top-center of the hemispherical shell, and others are disposed on the hemispherical shell at 5 circles surrounding the center;

downward from the top-center of the hemispherical shell, a first circle is formed by eight evenly distributed mounting holes where four pressure/touch sensors and four ground points are alternately disposed; and

for a second circle to a fifth circle downward from the top-center of the hemispherical shell, each circle is provided with twelve pressure/touch sensors and adjacent pressure/touch sensors are spaced at a center angle of 30°

; and

twelve ground points are alternately arranged among the pressure/touch sensors on a fourth circle.

12. The system of claim 9, wherein

a bottom part of the femoral head trial is a hemispherical shell connected to a hollow stem;

a plurality of contact points are distributed symmetrically on the flank of the stem; and

an auxiliary sensor is disposed at each contact point and is connected to an alarm device via the peripheral circuit.