A pressure measurement device, preparation method, and pressure measurement equipment

Abstract

The present invention relates to the technical field of medical devices applied to artificial knee joint replacement surgery, and discloses a pressure measurement device, a preparation method and a pressure measurement equipment. Among them, the pressure measurement device is used to measure the pressure between artificial knee joint prostheses, and includes a substrate, a plurality of sensing units arranged on the surface of the substrate, and a packaging layer covering the sensing units. The substrate is arranged between the femoral component and the tibial component. The sensing units are arranged on one side of the substrate facing the femoral component, and at least can cover the area where the surface of the substrate contacts the bicondyles of the femoral component. The sensing unit includes a bottom electrode layer, a piezoelectric material layer and a top electrode layer arranged in a direction away from the substrate. The sensing unit is configured to convert the pressure applied by the femoral component to the surface of the substrate into an electrical signal and transmit it to an external signal processing device for analysis and processing to determine the pressure information on the surface of the substrate.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices applied to artificial knee joint replacement surgery, and particularly relates to a pressure measurement device, a preparation method and a pressure measurement equipment. Background Art

[0002] With the increasing aging of the population, the number of patients suffering from knee joint diseases has been on the rise in recent years. Knee joint diseases can cause discomfort such as knee joint pain, swelling, and reduced range of motion, seriously affecting the daily life of patients. Artificial knee joint replacement surgery is a relatively effective method for treating knee joint diseases at present, which can relieve the pain of patients and improve the quality of life of patients.

[0003] When performing artificial knee joint replacement, a tibial spacer needs to be set between the tibial component and the femoral component of the knee joint prosthesis. The force on the upper surface of the tibial spacer between the medial condyle and the lateral condyle of the femoral component is often unbalanced. During the operation, doctors often adjust the tightness of the ligaments on both sides of the knee joint to adjust the force balance, so that the force is reasonable after the artificial knee joint is implanted into the human body and the quality of life of patients after surgery is improved.

[0004] In the prior art, doctors cannot accurately obtain the force condition between knee joint prostheses. Doctors usually insert their fingers into both sides of the knee joint cavity and adjust the tightness of the ligaments based on experience, which brings certain risks and unstable factors to artificial knee joint replacement surgery. Once the adjustment is improper, it will affect the postoperative rehabilitation of patients. Summary of the Invention

[0005] The present invention provides a pressure measurement device, a preparation method and a pressure measurement equipment to solve the problem in the prior art that in artificial knee joint replacement surgery, the force condition between knee joint prostheses cannot be accurately obtained, and thus the guarantee for ligament adjustment cannot be provided.

[0006] In a first aspect, an embodiment of the present invention provides a pressure measurement device. The pressure measurement device is used to measure the pressure between artificial knee joint prostheses, and includes a substrate, a plurality of sensing units arranged on the surface of the substrate, and a packaging layer covering the sensing units. The substrate is arranged between the femoral component and the tibial component. The plurality of sensing units are arranged on the side of the substrate facing the femoral component, and the plurality of sensing units can at least cover the area where the surface of the substrate contacts the bicondyles of the femoral component. The sensing unit includes a bottom electrode layer, a piezoelectric material layer, and a top electrode layer arranged in a direction away from the substrate. The sensing unit is configured to convert the pressure applied by the femoral component to the surface of the substrate into an electrical signal and transmit it to an external signal processing device for analysis and processing to determine the pressure information on the surface of the substrate.

[0007] In the above embodiments, the sensing unit is integrated on the substrate. When subjected to the pressure applied by the femoral component, it can output an electrical signal using the piezoelectric effect. After being analyzed and processed by the signal processing device, the electrical signal is converted into pressure information. In this way, the doctor can adjust the tightness of the knee ligament according to the obtained pressure information, so that the tibial spacer is evenly stressed, avoiding local friction and ensuring the patient's postoperative rehabilitation. In addition, the sensing unit does not require a power supply for driving during operation and has the characteristics of small size and thin thickness. It can collect the pressure information of the double-condyle irregular and uneven curved surface of the femoral component and can adapt to the special service environment of the knee joint.

[0008] Optionally, a plurality of the sensing units are distributed in an array on the surface of the substrate.

[0009] In the above embodiment, by arranging the sensing units in an array on the surface of the substrate, the density of the sensing units on the surface of the substrate is increased, and the sensitivity is improved.

[0010] Optionally, a plurality of the sensing units include a first group of sensing units and a second group of sensing units. The first group of sensing units is arranged in a first area on the surface of the substrate, and the second group of sensing units is arranged in a second area on the surface of the substrate. The first area corresponds to the medial condyle of the femoral component, the second area corresponds to the lateral condyle of the femoral component, and a transition area is provided between the first area and the second area.

[0011] Optionally, the encapsulation layer covers at least the top surface of the sensing unit facing away from the substrate and the side surface of the sensing unit.

[0012] In the above embodiment, the top surface and the side surface of the sensing unit both have exposed electrode materials. By making the encapsulation layer cover at least the top surface and the side surface of the sensing unit, it can play an insulating and protective role and can avoid being affected by the moisture inside the knee joint.

[0013] Optionally, the encapsulation layers of a plurality of the sensing units are connected to form an integral structure.

[0014] Optionally, the piezoelectric material layer is a thin film structure formed by one or a mixture of both inorganic piezoelectric materials and organic piezoelectric materials.

[0015] Optionally, the piezoelectric material layer is a thin film structure formed by sputtering an inorganic piezoelectric material, or the piezoelectric material layer is a thin film structure formed by electrospinning an organic piezoelectric material.

[0016] Optionally, the substrate is a thin film structure and is configured to be pasted on the tibial spacer in the artificial knee joint prosthesis.

[0017] In the above embodiments, the substrate is a thin film structure. During the operation, the substrate can be pasted onto the tibial spacer in the artificial knee joint prosthesis, and the signal transmission channel between the sensing unit and the signal processing device is connected. Thus, the pressure information applied by the two condyles of the femoral component to the tibial spacer can be measured, and the tightness of the ligaments on both sides of the knee joint can be adjusted according to the measured pressure information. After the adjustment is completed, the substrate can be peeled off from the tibial spacer, which is convenient to use. Moreover, the substrate can adapt to tibial spacers produced by different manufacturers and has strong adaptability.

[0018] Optionally, the sum of the thicknesses of the substrate and the sensing unit is not greater than 1.0 mm.

[0019] In the above embodiments, the total thickness of the substrate and the sensing unit can be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, etc. During the operation, when the tightness of the ligaments on both sides of the knee joint is adjusted according to the measured pressure information, the substrate can be peeled off from the tibial spacer. Since the total thickness of the substrate and the sensing unit is relatively thin, it will not affect the fit between the femoral component and the tibial spacer after peeling.

[0020] Optionally, the pressure measuring device further includes a protective film, and the protective film is detachably disposed on the surfaces of the substrate and the encapsulation layer.

[0021] In the above embodiments, the protective film can protect the surfaces of the substrate and the encapsulation layer during the transportation and storage stages of the pressure measuring device, and prevent impurities such as dust in the air from adhering to the surfaces and causing pollution.

[0022] Optionally, the substrate has the same shape and size as the tibial spacer in the artificial knee joint prosthesis.

[0023] In the above embodiments, the sensing unit is integrated on a substrate having the same shape and size as the tibial spacer. During the adjustment of the ligaments on both sides of the knee joint, the substrate is temporarily placed at the position of the tibial spacer, so as to collect the pressure information applied by the femoral component to the surface of the substrate through the sensing unit, providing data support for the adjustment of the ligaments. After the adjustment is completed, the substrate is taken out, and then the tibial spacer is installed between the femoral component and the tibial component.

[0024] In a second aspect, an embodiment of the present invention further provides a preparation method for the pressure measuring device according to any one of the above technical solutions. The preparation method includes:

[0025] Prepare a substrate, and block a part of the surface of the substrate through an occluder to form an occlusion area and a plurality of exposed areas on the surface of the substrate;

[0026] Successively prepare a bottom electrode layer, a piezoelectric material layer, and a top electrode layer on the exposed areas;

[0027] A packaging layer is prepared on the surface of the top electrode layer.

[0028] In the above embodiments, when a part of the surface of the substrate is shielded by an occluder, sensing units can be formed in multiple other exposed areas. In this way, the sensing units are distributed at different positions on the substrate and are spaced apart from each other, and they can be unaffected by internal stress. At the same time, the sensing units do not require power supply during operation and have the characteristics of small size and thin thickness. They can collect the pressure information of the double-condyle irregular and uneven curved surface of the femoral component and can adapt to the special service environment of the knee joint.

[0029] Optionally, the step of shielding a part of the surface of the substrate by an occluder to form a shielding area and multiple exposed areas on the surface of the substrate specifically includes:

[0030] Attach cross-set tapes on the surface of the substrate. The part covered by the tapes forms the shielding area, and the part not covered by the tapes forms the exposed areas.

[0031] In a third aspect, an embodiment of the present invention further provides a pressure measurement device. The pressure measurement device includes the pressure measurement device described in any one of the above technical solutions, and further includes a signal processing device and a display device. The signal processing device is connected to the sensing unit and is configured to determine the pressure information on the surface of the substrate according to the electrical signal output by the sensing unit;

[0032] The display device is connected to the signal processing device and is used to display the pressure information on the surface of the substrate.

[0033] In the above embodiments, when the sensing units distributed on the surface of the substrate are subjected to the pressure applied by the femoral component, they can output electrical signals by using the piezoelectric effect. After the signal processing device determines the pressure information on the surface of the substrate according to the electrical signals output by the sensing units, it can be transmitted to the display device, so that the pressure information on the surface of the substrate is displayed in real time on the screen through the display device, which is convenient for doctors to view and assist doctors in ligament adjustment. Description of the Drawings

[0034] Figure 1 It is a schematic diagram of the position in the knee joint during the use of the pressure measurement device provided by the embodiment of the present invention;

[0035] Figure 2 It is a schematic diagram of the distribution of the sensing units on the surface of the substrate in the pressure measurement device provided by the embodiment of the present invention;

[0036] Figure 3 It is a partial cross-sectional view of a pressure measurement device provided by the embodiment of the present invention;

[0037] Figure 4 A partial cross-sectional view of another pressure measurement device provided by an embodiment of the present invention;

[0038] Figure 5 A preparation flow chart of the pressure measurement device provided by an embodiment of the present invention;

[0039] Figure 6 A schematic diagram of the composition of the pressure measurement device provided by an embodiment of the present invention.

[0040] Reference numerals:

[0041] 10 - Pressure measurement device; 11 - Substrate; 111 - First region; 112 - Second region; 113 - Third region; 12 - Sensing unit; 12a - First group of sensing units; 12b - Second group of sensing units; 121 - Bottom electrode layer; 122 - Piezoelectric material layer; 123 - Top electrode layer; 13 - Encapsulation layer; 14 - Protective film; 20 - Femoral component; 201 - Medial condyle; 202 - Lateral condyle; 30 - Tibial component; 40 - Signal processing device; 50 - Display device. Detailed implementation manners

[0042] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0043] An embodiment of the present invention provides a pressure measurement device to solve the problem in the prior art that in artificial knee joint replacement surgery, the force condition between knee joint prostheses cannot be accurately obtained, and thus the guarantee for ligament adjustment cannot be provided.

[0044] Such as Figure 1 、 Figure 2 、 Figure 3 、 Figure 4As shown, the pressure measurement device 10 is used to measure the pressure between artificial knee joint prostheses, and includes a base body 11, a plurality of sensing units 12 arranged on the surface of the base body 11, and a packaging layer 13 covering the sensing units 12. The base body 11 is arranged between the femoral component 20 and the tibial component 30. The sensing units 12 are arranged on one side of the base body 11 facing the femoral component 20, and at least can cover the area where the surface of the base body 11 contacts the bicondyles of the femoral component 20. The sensing unit 12 includes a bottom electrode layer 121, a piezoelectric material layer 122, and a top electrode layer 123 arranged in the direction away from the base body 11. The sensing unit 12 is configured to convert the pressure applied by the femoral component 20 to the surface of the base body 11 into an electrical signal, and transmit it to an external signal processing device for analysis and processing to determine the pressure information on the surface of the base body 11.

[0045] Specifically, in the pressure measurement device 10, a plurality of sensing units 12 are arranged on the surface of the base body 11. These sensing units 12 can at least cover the area where the surface of the base body 11 contacts the bicondyles of the femoral component 20. The sensing unit 12 includes a piezoelectric material, and the piezoelectric material has a piezoelectric effect, that is, when the crystal is subjected to an external force in a certain fixed direction, an electropolarization phenomenon will occur inside, and at the same time, opposite charges will be generated on two certain surfaces. When the external force is removed, the crystal returns to the uncharged state, and the amount of charge generated by the crystal under the action of the force is proportional to the magnitude of the external force. That is to say, when the sensing unit 12 is subjected to the pressure applied by the femoral component 20, it can output an electrical signal by using the piezoelectric effect of the piezoelectric material. The stronger the electrical signal, the greater the pressure received. On the contrary, the weaker the electrical signal, the smaller the pressure received. The electrical signal can be converted into pressure information through the analysis and processing of the signal processing device. This pressure information includes the magnitude of the pressure and the distribution of the pressure. That is to say, it is determined which part of the tibial spacer is under pressure and how large the pressure is, etc. In this way, the doctor can adjust the tightness of the knee ligament according to the obtained pressure information, so that the tibial spacer is evenly stressed, avoid excessive local friction, and ensure the postoperative rehabilitation of the patient.

[0046] The sensing units 12 are distributed at different positions on the base body 11, and are spaced from each other and not affected by internal stress. The sensing unit 12 specifically includes a bottom electrode layer 121, a piezoelectric material layer 122, and a top electrode layer 123. Since the piezoelectric material has a piezoelectric effect, the sensing unit 12 does not require a power supply for driving during operation. Moreover, the bottom electrode layer 121, the piezoelectric material layer 122, and the top electrode layer 123 are all ultra-thin film layers, which makes the sensing unit 12 have the characteristics of small volume and thin thickness, and can collect the pressure information of the irregular and uneven curved surfaces of the bicondyles of the femoral component 20, so as to adapt to the special service environment of the knee joint.

[0047] Optionally, the electrode materials that can be used for the bottom electrode layer 121 and the top electrode layer 123 can be any one of copper (Cu), silver (Ag), gold (Au), platinum (Pt), and palladium (Pd). The electrode materials are required to have low resistance and no ferromagnetism, and specifically, can be deposited on the surface of the substrate 11 by sputtering or evaporation.

[0048] The piezoelectric material layer 122 can use inorganic piezoelectric materials, organic piezoelectric materials, or a mixture of both. Among them, inorganic piezoelectric materials have a higher piezoelectric coefficient. The inorganic piezoelectric material can be any one of zinc oxide (ZnO), barium titanate (BaTiO 3 ), lead zirconate titanate (Pb(Zr,Ti)O 3 ), gallium nitride (GaN), zinc stannate (ZnSnO 3 ), sodium niobate (NaNbO 3 ), potassium niobate (KNbO 3 ), lithium niobate (KNbO 3 ), bismuth ferrite (BiFeO 3 ), and specifically, the inorganic piezoelectric material can be formed on the surface of the bottom electrode layer 121 through a sputtering process.

[0049] Organic piezoelectric materials can withstand large deformations and are flexible. The organic piezoelectric material can be any one of polyvinylidene fluoride (PVDF), the PVDF derivative PVDF-TrFE, and P(VDF / TFE). Specifically, the organic piezoelectric material can be formed on the surface of the bottom electrode layer 121 by an electrospinning process.

[0050] After the piezoelectric material is prepared, high-voltage polarization is performed to enhance its piezoelectric coefficient and piezoelectric performance.

[0051] A packaging layer 13 is also provided on the surface of the sensing unit 12. The packaging layer 13 can specifically be a Parylene coating, as shown in Figure 3 、 Figure 4 . The packaging layer 13 covers at least the top surface of the sensing unit 12 facing away from the substrate 11 and the side surface of the sensing unit 12. This is because the top surface and the side surface of the sensing unit 12 both have exposed electrode materials. By making the packaging layer 13 cover at least the top surface and the side surface of the sensing unit 12, it can play an insulating and protective role, and can also avoid being affected by the moisture inside the knee joint.

[0052] Each sensing unit 12 can have an independent packaging layer 13, or alternatively, the packaging layers 13 of multiple sensing units 12 can be connected to form an integrated structure. For the latter case, it can simplify the preparation process and improve the flatness of the surface of the substrate 11.

[0053] The sensing unit 12 can at least cover the area on the surface of the base body 11 that comes into contact with the femoral component 20. The sensing units 12 can be randomly arranged on the surface of the base body 11 or arranged according to certain rules. For example, one sensing unit 12 can be taken as the center, and the sensing units 12 can be radially dispersed around this sensing unit 12. Or, as Figure 2 shown, they can also be arranged in an array on the surface of the base body 11. Specifically, multiple sensing units 12 form multiple rows and columns on the surface of the base body 11, which increases the density of the sensing units 12 on the surface of the base body 11 and improves the sensitivity.

[0054] Continuing to refer to Figure 2 , the multiple sensing units 12 include a first group of sensing units 12a and a second group of sensing units 12b. The first group of sensing units 12a is arranged in a first area 111 on the surface of the base body 11, and the second group of sensing units 12b is arranged in a second area 112 on the surface of the base body 11. The first area 111 corresponds to the medial condyle 201 of the femoral component 20, and the second area 112 corresponds to the lateral condyle 202 of the femoral component 20. A transition area 113 is provided between the first area 111 and the second area 112.

[0055] The first group of sensing units 12a can be arranged in an array or in other forms in the first area 111. Similarly, the second group of sensing units 12b can be arranged in an array or in other forms in the second area 112. During the operation, it is possible to judge whether the bicondylar forces of the femoral component 20 are balanced according to the pressure information collected by the first group of sensing units 12a and the second group of sensing units 12b.

[0056] The transition area 113 is located between the first area 111 and the second area 112, and no sensing unit 12 is provided in the transition area 113. In the case where the base body 11 described below is a thin film structure, when the base body 11 is pasted on the surface of the tibial spacer in the artificial knee joint prosthesis, the transition area 113 can be caused to have a certain degree of wrinkling, so that the first area 111 corresponds to the medial condyle 201 of the femoral component 20, and the second area 112 corresponds to the lateral condyle 202 of the femoral component 20.

[0057] In some embodiments, the base body 11 is a thin film structure, and the base body 11 is configured to be pasted on the surface of the tibial spacer in the artificial knee joint prosthesis.

[0058] During the operation, the substrate 11 can be pasted onto the tibial spacer in the artificial knee joint prosthesis, and the signal transmission channel between the sensing unit 12 and the signal processing device can be connected, so that the pressure information applied by the bicondyles of the femoral component 20 to the tibial spacer can be measured, and the tightness of the ligaments on both sides of the knee joint can be adjusted according to the measured pressure information. After the adjustment is completed, the substrate 11 can be peeled off the tibial spacer. It is convenient to use, safe and hygienic, and will not cause cross-contamination. Moreover, the substrate 11 is a thin film structure and has flexibility, so it can be applied to tibial spacers with different structures produced by different manufacturers, having strong adaptability.

[0059] The surface of the tibial spacer facing the femoral component may not be a flat surface, and the corresponding part between the bicondyles of the femoral component is higher, while the transition region 113 in the middle of the substrate 11 can adapt to the structure of this tibial spacer.

[0060] In addition, the overall thickness of the substrate 11 and the sensing unit 12 is relatively thin. After adjusting the tightness of the ligaments on both sides of the knee joint and peeling the substrate 11 from the surface of the tibial spacer, it will not affect the fit between the femoral component 20 and the tibial spacer.

[0061] Optionally, the sum of the thicknesses of the sensing unit 12 is not greater than 1.0 mm. For example, it can be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, etc.

[0062] As Figure 4 shown, the pressure measuring device 10 further includes a protective film 14, and the protective film 14 is detachably disposed on the surfaces of the substrate 11 and the encapsulation layer 13. The protective film 14 can protect the surfaces of the substrate 11 and the encapsulation layer 13 during the transportation and storage stages of the pressure measuring device 10, avoiding the attachment of impurities such as dust in the air and causing contamination.

[0063] In other embodiments, the substrate 11 has the same shape and size as the tibial spacer in the artificial knee joint prosthesis. At this time, the sensing unit 12 is integrated on the substrate 11 having the same shape and size as the tibial spacer. During the adjustment of the ligaments on both sides of the knee joint, the substrate 11 is temporarily placed between the femoral component 20 and the tibial component 30, that is, the position of the tibial spacer, so as to collect the pressure information applied by the femoral component 20 to the surface of the substrate 11 through the sensing unit 12, providing data support for the adjustment of the ligaments. After the adjustment is completed, the substrate 11 is taken out, and then the tibial spacer is installed between the femoral component 20 and the tibial component 30. Since the substrate 11 has the same shape and size as the tibial spacer in the artificial knee joint prosthesis, and the sensing unit 12 is also an ultra-thin structure, the force-bearing situation of the substrate 11 is the same as that of the tibial spacer.

[0064] After the sensing unit 12 is integrated on the surface of the substrate 11, the position of the sensing unit 12 on the surface of the substrate 11 is relatively fixed. Thus, the pressure distribution on the surface of the substrate 11 can be accurately obtained according to the position information of the sensing unit 12 and the collected pressure information.

[0065] In addition, the substrate 11 can be a hollow structure, and the space inside the substrate 11 can be used to arrange components such as wire harnesses, so as to transmit the electrical signals generated by the sensing unit 12 to the external signal processing device 40.

[0066] Based on the same inventive concept, as Figure 5 shown, an embodiment of the present invention further provides a preparation method of the pressure measurement device 10 of any one of the above technical solutions. The preparation method includes:

[0067] Step S101: Prepare the substrate 11, where the substrate 11 can be a thin film structure or a three-dimensional structure having the same shape and size as the tibial spacer;

[0068] Step S102: Block a part of the surface area of the substrate 11 with an occlusion object to form an occlusion area and a plurality of exposed areas on the surface of the substrate 11;

[0069] Step S103: Sequentially prepare a bottom electrode layer 121, a piezoelectric material layer 122, and a top electrode layer 123 in the exposed areas;

[0070] Step S104: Prepare an encapsulation layer 13 on the surface of the top electrode layer 123.

[0071] Optionally, in step S102, blocking a part of the surface area of the substrate 11 with an occlusion object to form an occlusion area and a plurality of exposed areas on the surface of the substrate 11 specifically includes:

[0072] Attach cross-set tapes to the surface of the substrate 11. The covered part forms an occlusion area, and the uncovered part forms an exposed area.

[0073] That is to say, tapes can be used as the occlusion object to form a horizontal and vertical cross-shaped network structure on the surface of the substrate 11, so as to form a plurality of exposed areas, and these exposed areas are arranged in an array. In this way, in the exposed areas, a sensing unit 12 with a bottom electrode layer 121, a voltage material layer, and a top electrode layer 123 can be formed. After removing the occlusion object, an encapsulation layer 13 is formed on the surface of the substrate 11, so that the encapsulation layer 13 covers the top surface and side surfaces of the sensing unit 12.

[0074] Optionally, the material of the tape is polyimide.

[0075] The preparation process also includes other process steps, such as polarizing the piezoelectric material and setting wires for transmitting electrical signals when preparing the bottom electrode layer 121 and the top electrode layer 123, which will not be described in detail here.

[0076] The preparation process of the pressure measuring device 10 is now specifically described using the following embodiment, including:

[0077] According to the number and size of the required sensing units 12, polyimide tape is used to divide them and cover the parts where no deposition is performed. For example, polyimide tape with a width of 5 mm is used to divide the surface of the substrate 11 into a square array with a side length of 1 cm in a horizontal and vertical staggered manner;

[0078] The bottom electrode layer 121 is prepared by depositing a gold (Au) target material by direct current magnetron sputtering, with a power of 100-150 W and a time of 10-15 min. The thickness of the prepared bottom electrode layer 121 is 100-200 nm.

[0079] The piezoelectric material layer 122 is prepared by magnetron sputtering a barium titanate (BaTiO3) target material at a power of 50-100 W for 10-30 min. The thickness of the prepared piezoelectric material layer 122 is 100-200 nm.

[0080] A gold (Au) target is deposited on the surface of the piezoelectric material layer 122 by direct current magnetron sputtering to prepare a top electrode layer 123; the power is 100-150W, the time is 10-15min, and the thickness of the prepared top electrode layer 123 is 100-200nm;

[0081] The polyimide tape is removed, and the surface of the substrate 11 is encapsulated with parylene;

[0082] The piezoelectric material layer 122 is polarized with a polarization electric field strength of 1 kV / cm-10 kV / cm for 15-30 min.

[0083] Finally, the sensing unit 12 is connected to the outside to perform a performance test.

[0084] Based on the same technical concept, the embodiment of the present invention also provides a pressure measurement device, such as Figure 6 As shown, the measuring device includes the pressure measuring device 10 in any of the above-mentioned technical solutions, and also includes a signal processing device 40 and a display device 50. The signal processing device 40 is connected to the sensor unit 12 and is configured to determine the pressure information on the surface of the substrate 11 according to the electrical signal output by the sensor unit 12; the display device 50 is connected to the signal processing device 40 and is used to display the pressure information on the surface of the substrate 11.

[0085] When the sensing unit 12 distributed on the surface of the substrate 11 is subjected to the pressure applied by the femoral component 20, it can output an electrical signal by utilizing the piezoelectric effect. After the signal processing device 40 determines the pressure information on the surface of the substrate 11 according to the electrical signal output by the sensing unit 12, it can be transmitted to the display device 50, so that the pressure information on the surface of the substrate 11 is displayed in real time on the screen through the display device 50, thereby facilitating the doctor's viewing and assisting the doctor in ligament adjustment.

[0086] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these changes and modifications therein.

Claims

1. A pressure measurement device, characterized in that, for measuring the pressure between artificial knee joint prostheses, including a substrate, a plurality of sensing units disposed on the surface of the substrate, and a packaging layer covering the sensing units, the substrate is disposed between a femoral component and a tibial component, and the plurality of sensing units are disposed on one side of the substrate facing the femoral component, and the plurality of sensing units can at least cover the area where the surface of the substrate contacts the bicondyles of the femoral component. The sensing unit includes a bottom electrode layer, a piezoelectric material layer, and a top electrode layer disposed in a direction away from the substrate. The sensing unit is configured to convert the pressure applied by the femoral component to the surface of the substrate into an electrical signal and transmit it to an external signal processing device for analysis and processing to determine the pressure information on the surface of the substrate; the piezoelectric material layer is a thin film structure formed by sputtering an inorganic piezoelectric material, or the piezoelectric material layer is a thin film structure formed by electrospinning an organic piezoelectric material; the thickness of the bottom electrode layer is 100 - 200 nm, the thickness of the piezoelectric material layer is 100 - 200 nm, the thickness of the top electrode layer is 100 - 200 nm, and the sum of the thicknesses of the substrate and the sensing unit is not greater than 1.0 mm; the plurality of sensing units include a first group of sensing units and a second group of sensing units. The first group of sensing units is disposed in a first area on the surface of the substrate, and the second group of sensing units is disposed in a second area on the surface of the substrate. The first area corresponds to the medial condyle of the femoral component, the second area corresponds to the lateral condyle of the femoral component, and a transition area is provided between the first area and the second area; the substrate is a thin film structure and is configured to be pasted on a tibial spacer in an artificial knee joint prosthesis.

2. The pressure measurement device according to claim 1, characterized in that, the plurality of sensing units are arranged in an array on the surface of the substrate.

3. The pressure measurement device according to claim 1 or 2, characterized in that, the packaging layer covers at least the top surface of the sensing unit facing away from the substrate and the side surface of the sensing unit.

4. The pressure measurement device according to claim 3, characterized in that, the packaging layers of the plurality of sensing units are connected to form an integral structure.

5. The pressure measurement device according to claim 1 or 2, characterized in that, the piezoelectric material layer is a thin film structure formed by one or a mixture of both an inorganic piezoelectric material and an organic piezoelectric material.

6. The pressure measurement device according to claim 1 or 2, characterized in that, the pressure measurement device further includes a protective film, and the protective film is detachably disposed on the surfaces of the substrate and the packaging layer.

7. The pressure measurement device according to claim 1 or 2, characterized in that, the substrate has the same shape and size as the tibial spacer in the artificial knee joint prosthesis.

8. A preparation method of the pressure measurement device according to any one of claims 1 to 7, characterized in that, comprising: Prepare a substrate, and cover a partial area of the surface of the substrate with an occluder to form an occluded area and a plurality of exposed areas on the surface of the substrate; Successively prepare a bottom electrode layer, a piezoelectric material layer, and a top electrode layer in the exposed areas; Prepare a packaging layer on the surface of the top electrode layer; Successively prepare a bottom electrode layer, a piezoelectric material layer, and a top electrode layer in the exposed areas, specifically including: Deposit a gold target by DC magnetron sputtering to prepare the bottom electrode layer, and the thickness of the prepared bottom electrode layer is 100-200 nm; deposit a barium titanate target by radio magnetron sputtering to prepare the piezoelectric material layer, and the thickness of the prepared piezoelectric material layer is 100-200 nm; deposit a gold target on the surface of the piezoelectric material layer by DC magnetron sputtering to prepare the top electrode layer, and the thickness of the prepared top electrode layer is 100-200 nm.

9. The preparation method according to claim 8, wherein, the covering a partial area of the surface of the substrate with an occluder to form an occluded area and a plurality of exposed areas on the surface of the substrate specifically includes: Attach cross-set tapes on the surface of the substrate, the covered part by the tapes forms the occluded area, and the uncovered part by the tapes forms the exposed areas.

10. A pressure measurement device, wherein, it includes the pressure measurement device according to any one of claims 1 to 7, and further includes a signal processing device and a display device. The signal processing device is connected to the sensing unit and is configured to determine the pressure information on the surface of the substrate according to the electrical signal output by the sensing unit; The display device is connected to the signal processing device and is used to display the pressure information on the surface of the substrate.

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