Implantable pressure sensor based on corrugated structure optimization

Abstract

The invention relates to the field of implantable pressure sensors, and discloses a corrugated structure optimization-based implantable pressure sensor, which comprises a corrugated diaphragm, a pressure sensing diaphragm and a support base, the corrugated diaphragm is arranged on the upper side of the pressure sensing diaphragm, the pressure sensing diaphragm is arranged on the upper side of the supporting base, and a pressure sensing cavity is formed between the pressure sensing diaphragm and the supporting base; the corrugated diaphragm comprises a corrugated part and a flat part which are integrally formed, the corrugated part is a pressure sensing part, and the flat part is a joint part and is attached to the pressure sensing diaphragm; and the section curve of the corrugated part is a periodic sine curve and is concentrically and gradually distributed. By optimizing the corrugated structure, stress under dynamic pressure is effectively dispersed, stress concentration is relieved, the long-term anti-fatigue performance and measurement stability of the sensor are improved, and the requirements of implantable medical monitoring scenes are met.

Description

Technical Field

[0001] This invention relates to the field of implantable pressure sensor technology, and more specifically to an implantable pressure sensor based on corrugated structure optimization. Background Technology

[0002] Implantable pressure sensors, as core monitoring devices in the medical field, play an irreplaceable role in scenarios such as intracranial pressure monitoring and vascular hemodynamic assessment. Their measurement accuracy, long-term stability, and biocompatibility are directly related to the accuracy of disease diagnosis and the safety of treatment. With the development of minimally invasive medical technology, higher requirements have been placed on the miniaturization, fatigue resistance, and scenario adaptability of implantable pressure sensors. Especially in scenarios where they are subjected to long-term periodic dynamic loads (such as vasoconstriction and vasodilation of blood vessel walls and intracranial pressure fluctuations), the structural design of the sensor becomes a key factor affecting its performance and service life.

[0003] In existing technologies, some implantable pressure sensors have adopted corrugated diaphragms instead of traditional flat diaphragms to alleviate stress concentration problems. However, several technical defects still exist: First, the structural design of existing corrugated diaphragms is relatively simple, often employing symmetrical structures with uniform wave pitch and height. These designs are not optimized for the dynamic pressure characteristics of implantable applications, leading to uneven stress distribution. Under long-term cyclic loading, stress concentration can still occur at the center of the diaphragm and at the interface with the flat portion, causing fatigue fracture or interface delamination, severely affecting the long-term reliability of the sensor. Second, the bonding between the corrugated diaphragm and the pressure-sensing diaphragm relies heavily on simple adhesive fixation, lacking a positioning structure. After implantation, relative displacement can easily occur due to changes in body position, tissue friction, and other factors. First, the design of the corrugated diaphragm does not fully consider biocompatibility requirements, resulting in sharp edges and high frictional resistance with blood flow or surrounding tissues. Long-term implantation may induce thrombosis or tissue hyperplasia, increasing clinical risks. Second, the existing corrugated diaphragm has fixed structural parameters, making it difficult to simultaneously adapt to the measurement needs of different pressure ranges, such as intracranial hypotension (0-20 kPa) and vascular hypertension (10-200 kPa), resulting in poor scenario adaptability. Third, some corrugated diaphragms use symmetrical cross-sectional curves, which slows down the response to sudden changes in dynamic pressure and cannot accurately capture rapid pressure changes such as vasoconstriction, affecting the timeliness and accuracy of dynamic measurements.

[0004] The aforementioned problems result in short lifespan, unstable measurement accuracy, and limited clinical applicability of existing implantable pressure sensors in long-term dynamic pressure monitoring, which restricts their further application in the medical field. Summary of the Invention

[0005] To solve or at least partially solve the above-mentioned technical problems, the present invention provides an implantable pressure sensor based on corrugated structure optimization.

[0006] This invention provides an implantable pressure sensor based on a corrugated structure optimization, comprising: a corrugated diaphragm, a pressure-sensing diaphragm, and a support base; the corrugated diaphragm is disposed on the upper side of the pressure-sensing diaphragm; the pressure-sensing diaphragm is disposed on the upper side of the support base, and a pressure-sensing cavity is disposed between the two; The corrugated diaphragm includes an integrally formed corrugated portion and a flat portion. The corrugated portion is a pressure-sensitive portion, and the flat portion is a joint portion and is attached to the pressure-sensitive diaphragm. The cross-sectional curve of the corrugated part is a periodic sine curve, and the corrugated part is distributed in a concentric gradient.

[0007] Optionally, the wave pitch λ and wave height h of the corrugated part satisfy λ=3h~5h, and the wave height h is gradually set from the center of the corrugated part to the edge of 10μm~20μm.

[0008] Optionally, when the implantable pressure sensor is adapted for intracranial pressure measurement, the wave distance λ of the corrugated portion is 3h; when the implantable pressure sensor is adapted for vascular pressure measurement, the wave distance λ of the corrugated portion is 5h.

[0009] Optionally, the number of cycles of the corrugated portion is 3 to 8, and the number of cycles increases from the inside to the outside along the radial direction of the corrugated portion.

[0010] Optionally, the crests and troughs of the corrugated portion are provided with transition fillets, and the radius of the transition fillets is ≥5μm.

[0011] Optionally, the connection between the corrugated portion and the flat portion is provided with a gentle transition slope, the slope of which is 1:3.

[0012] Optionally, an annular positioning groove is provided on the side of the flat portion away from the corrugated portion, and the annular positioning groove is adapted to engage with the edge of the pressure-sensitive diaphragm.

[0013] Optionally, the flat portion is provided with radial reinforcing ribs on the side facing the pressure-sensitive diaphragm, and the reinforcing ribs extend radially along the corrugated portion and correspond one-to-one with the trough positions of the corrugated portion.

[0014] Optionally, the cross-sectional sinusoidal curve of the corrugated portion is asymmetrically arranged, with the arc length of the rising edge of the corrugated portion being greater than the arc length of the falling edge, and the radius of curvature of the rising edge being smaller than the radius of curvature of the falling edge.

[0015] Optionally, the outer edge of the corrugated portion is provided with an outwardly inclined smooth flange, the flange transitions to the upper surface of the flat portion at an obtuse angle, and the outer surface of the flange smoothly connects to the trough surface of the corrugated portion.

[0016] Compared with the prior art, the present invention achieves the following technical effects: The implantable pressure sensor based on the optimized corrugated structure of the present invention, by designing the corrugated part as a combination of a periodic sine curve and a concentric gradually distributed structure, makes the stress under pressure uniformly distributed along the radial direction of the corrugation, effectively alleviating the stress concentration problem of traditional flat diaphragms or single-structure corrugated diaphragms under dynamic pressure, and significantly improving the fatigue resistance and service life of the sensor under long-term cyclic loads (such as vascular pulsation and intracranial pressure fluctuations).

[0017] The rounded corners at the crests and troughs of the corrugated section, and the gentle slope design between the corrugated and flat sections, further eliminate stress abrupt changes at the structural interface, making deformation transmission smoother and avoiding the risk of interface peeling during long-term use. The setting of the asymmetric cross-section sine curve optimizes the response characteristics of dynamic pressure, which can quickly capture pressure abrupt change signals and buffer the stress release process, improving the accuracy and stability of dynamic measurement.

[0018] The annular positioning groove in the flat section enables accurate positioning and stable fit between the corrugated diaphragm and the pressure-sensitive diaphragm, preventing relative displacement caused by changes in body position or tissue friction after implantation, and ensuring the consistency of measurement signals. The corresponding setting of the radial reinforcing ribs and the troughs of the corrugated section enhances the deformation transmission efficiency, avoids signal distortion caused by slight external contact, and improves the sensor's anti-interference capability.

[0019] The smooth flange design of the outer edge of the corrugated part reduces the frictional resistance between the sensor and human tissue and blood flow, thereby reducing the risk of thrombosis or tissue hyperplasia after implantation and adapting to the biocompatibility requirements of implantation scenarios. The adaptive ratio of wave distance to wave height and the gradual distribution of the number of cycles enable the sensor to flexibly match different implantation scenarios such as intracranial hypotension and vascular hypertension, thus broadening the application range.

[0020] In summary, this invention improves the measurement accuracy, fatigue resistance, scene adaptability, and biocompatibility of implantable pressure sensors through various optimized designs of the corrugated structure, and solves the technical problems of traditional implantable pressure sensors being prone to failure under dynamic pressure environments, having poor measurement stability, and being only suitable for a limited range of scenarios. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of an implantable pressure sensor based on corrugated structure optimization according to an embodiment of the present invention. Figure 2 An exploded view of an implantable pressure sensor based on corrugated structure optimization according to an embodiment of the present invention; Figure 3 A cross-sectional view of the corrugated section structure of an implantable pressure sensor based on corrugated structure optimization according to an embodiment of the present invention; Figure 4This is a schematic diagram of the back structure of the flat portion of an implantable pressure sensor based on corrugated structure optimization according to an embodiment of the present invention. Figure 5 A cross-sectional view of the corrugated section structure of an implantable pressure sensor based on corrugated structure optimization according to an embodiment of the present invention; Figure 6 A cross-sectional view of the corrugated section structure of an implantable pressure sensor based on corrugated structure optimization according to an embodiment of the present invention; Figure 7 A cross-sectional view of the corrugated section structure of an implantable pressure sensor based on corrugated structure optimization according to an embodiment of the present invention; Figure 8 This is a top view of the corrugated section structure of an implantable pressure sensor based on corrugated structure optimization, according to an embodiment of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings, not all of them. Before discussing exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe operations (or steps) as sequential processes, many of these operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but may also have additional steps not included in the drawings. The process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0023] The technical solutions of the embodiments of the present invention will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0024] See Figures 1 to 8 This invention provides an implantable pressure sensor based on a corrugated structure optimization, comprising: a corrugated diaphragm 1, a pressure-sensing diaphragm 2, and a support base 3; the corrugated diaphragm 1 is disposed on the upper side of the pressure-sensing diaphragm 2; the pressure-sensing diaphragm 2 is disposed on the upper side of the support base 3, and a pressure-sensing cavity 4 is disposed between the two; The corrugated diaphragm 1 includes an integrally formed corrugated portion 11 and a flat portion 12. The corrugated portion 11 is a pressure-sensitive portion, and the flat portion 12 is a joint portion and is attached to the pressure-sensitive diaphragm 2. The cross-sectional curve of the corrugated part 11 is a periodic sine curve, and the corrugated part 11 is distributed in a concentric gradient.

[0025] In some embodiments, the wave pitch λ and wave height h of the corrugated portion 11 satisfy λ=3h~5h, and the wave height h is gradually set from the center of the corrugated portion 11 to the edge in a range of 10μm~20μm.

[0026] In some embodiments, when the implantable pressure sensor is adapted for intracranial pressure measurement, the wave pitch λ of the corrugated portion 11 is 3h; when the implantable pressure sensor is adapted for vascular pressure measurement, the wave pitch λ of the corrugated portion 11 is 5h.

[0027] In some embodiments, the number of cycles of the corrugated portion 11 is 3 to 8, and the number of cycles increases radially from the inside to the outside along the corrugated portion 11.

[0028] In some embodiments, the crests and troughs of the corrugated portion 11 are provided with transition fillets 112, and the radius of the transition fillets 112 is ≥5μm.

[0029] In some embodiments, the connection between the corrugated portion 11 and the flat portion 12 is provided with a gentle transition slope 113, the slope of which is 1:3.

[0030] In some embodiments, the flat portion 12 is provided with an annular positioning groove 121 on the side away from the corrugated portion 11, and the annular positioning groove 121 is adapted to engage with the edge of the pressure-sensitive diaphragm 2.

[0031] In some embodiments, the flat portion 12 is provided with radial reinforcing ribs 122 on the side facing the pressure-sensitive diaphragm 2. The reinforcing ribs 122 extend radially along the corrugated portion 11 and correspond one-to-one with the trough positions of the corrugated portion 11.

[0032] In some embodiments, the cross-sectional sinusoidal curve of the corrugated portion 11 is asymmetrically arranged, the arc length of the rising edge of the corrugated portion 11 is greater than the arc length of the falling edge, and the radius of curvature of the rising edge is smaller than the radius of curvature of the falling edge.

[0033] In some embodiments, the outer edge of the corrugated portion 11 is provided with an outwardly inclined smooth flange 111, the flange 111 transitions to the upper surface of the flat portion 12 at an obtuse angle, and the outer surface of the flange 111 smoothly connects to the trough surface of the corrugated portion 11.

[0034] See Figures 1 to 3An embodiment of the present invention provides an implantable pressure sensor based on a corrugated structure optimization, comprising: a corrugated diaphragm 1, a pressure-sensing diaphragm 2, and a support base 3; the corrugated diaphragm 1 is disposed on the upper side of the pressure-sensing diaphragm 2; the pressure-sensing diaphragm 2 is disposed on the upper side of the support base 3, and a pressure-sensing cavity 4 is disposed between the two; the corrugated diaphragm 1 includes an integrally formed corrugated portion 11 and a flat portion 12, the corrugated portion 11 being the pressure-sensing portion, and the flat portion 12 being the joint portion and attached to the pressure-sensing diaphragm 2; the cross-sectional curve of the corrugated portion 11 is a periodic sine curve, and the corrugated portion 11 is concentrically and gradually distributed.

[0035] The pressure-sensitive diaphragm 2 can be made of monocrystalline silicon, the support base 3 can be made of Pyrex glass, and the corrugated diaphragm 1 can be made of PDMS. The thickness of the pressure-sensitive diaphragm 2 can be 50 μm and the diameter can be 1500 μm. The thickness of the support base 3 can be 400 μm and the diameter can be 1500 μm. The height of the pressure-sensitive cavity 4 can be 50 μm and the diameter can be 1200 μm.

[0036] Example 1: In this embodiment, the implantable pressure sensor is adapted to intracranial pressure measurement scenarios, such as... Figures 3 to 4 As shown, the wave pitch λ and wave height h of the corrugated portion 11 satisfy λ=3h, and the wave height h gradually changes from 10μm to 15μm from the center to the edge of the corrugated portion 11 (15μm at the center and 10μm at the edge). The corrugated portion 11 has 3 cycles, and the number of cycles increases radially from the inside to the outside of the corrugated portion 11 (1 cycle on the inner side, 1 cycle in the middle, and 1 cycle on the outer side). This structural design can improve the response sensitivity of pressure signals under intracranial low-pressure static conditions, while dispersing the radial stress of the corrugated portion under pressure, avoiding measurement errors caused by excessive local deformation. It should be noted that, due to size limitations, the quantities and dimensions in the accompanying drawings of the embodiment of the invention may not be completely consistent with the textual specifications; only the structural features are simply illustrated.

[0037] The corrugated portion 11 has transition fillets 112 at both its crests and troughs, with a radius of 5 μm, effectively reducing stress concentration points under low intracranial pressure. The flat portion 12 has radial reinforcing ribs 122 on the side facing the pressure-sensitive diaphragm 2. These ribs extend radially along the corrugated portion 11 and correspond one-to-one with the troughs of the corrugated portion 11. The reinforcing ribs 122 have a width of 20 μm and a thickness consistent with the flat portion 12, enhancing the stability of deformation transmission in the corrugated portion 11 and preventing signal distortion caused by slight contact with intracranial tissue.

[0038] An annular positioning groove 121 is provided on the side of the flat part 12 away from the corrugated part 11. The annular positioning groove 121 has a width of 50μm and a depth of 20μm. It is adapted to and engaged with the edge of the pressure-sensitive diaphragm 2 to achieve accurate positioning of the corrugated diaphragm 1 and the pressure-sensitive diaphragm 2, and to prevent relative displacement caused by changes in body position after implantation.

[0039] During assembly, the pressure-sensitive diaphragm 2 is first connected to the support base 3 by anodizing to form a sealed pressure-sensitive cavity 4; then the flat part 12 of the corrugated diaphragm 1 is subjected to low-temperature plasma treatment, and then the annular positioning groove 121 is aligned with the edge of the pressure-sensitive diaphragm 2 and snapped in to complete the bonding and fixing.

[0040] Example 2: In this embodiment, the implantable pressure sensor is adapted to vascular pressure measurement scenarios, such as... Figure 5 As shown, the wave pitch λ and wave height h of the corrugated section 11 satisfy λ=5h, and the wave height h gradually changes from 15μm to 20μm from the center to the edge of the corrugated section 11 (20μm at the center and 15μm at the edge). The corrugated section 11 has 8 cycles, and the number of cycles increases radially from the inside to the outside of the corrugated section 11 (2 cycles on the inner side, 3 cycles in the middle, and 3 cycles on the outer side; the wave height and wave pitch are the same within the same cycle; due to size limitations, the complete 8 cycles are not shown in the figure), which adapts to the deformation requirements of cyclic high-pressure loads on blood vessels. This structural design can buffer the impact of cyclic loads under dynamic conditions of high-pressure blood vessels, improve the fatigue resistance of the corrugated section, and ensure the response speed and measurement stability of dynamic pressure signals.

[0041] The cross-sectional sinusoidal curve of the corrugated section 11 is asymmetrically arranged. The arc length of the rising edge of the corrugated section 11 is greater than that of the falling edge, and the radius of curvature of the rising edge (8μm) is smaller than that of the falling edge (12μm). This allows for rapid response to pressure changes during vasoconstriction and buffers stress release during vasodilation, thereby improving the response speed of dynamic pressure measurement.

[0042] The outer edge of the corrugated portion 11 is provided with an outwardly inclined smooth flange 111. The flange 111 transitions to the upper surface of the flat portion 12 at a 120° obtuse angle, and the outer surface of the flange 111 smoothly connects to the trough surface of the corrugated portion 11. The width of the flange 111 is 30μm, which can reduce the frictional resistance between the implantable pressure sensor and the blood flow after implantation in the blood vessel, and reduce the risk of thrombosis.

[0043] During assembly, the corrugated diaphragm 1 and the pressure-sensitive diaphragm 2 are attached in the same way as in Embodiment 1, with the smooth flange 111 facing the direction of blood flow to ensure that the impact force on the sensor during blood flow is evenly distributed to the corrugated part 11.

[0044] Example 3: In this embodiment, the implantable pressure sensor is adaptable to multiple scenarios, such as... Figure 6As shown, the wave pitch λ and wave height h of the corrugated section 11 satisfy λ=4h, and the wave height h gradually changes from 12μm to 18μm from the center to the edge of the corrugated section 11. The corrugated section 11 has 5 cycles, which are uniformly increased radially. This structural design can take into account the sensitivity and overload resistance requirements of medium-pressure conditions in multiple scenarios, making the corrugated section deformation more uniform and further extending the long-term working life of the sensor.

[0045] The connection between the corrugated part 11 and the flat part 12 is provided with a gentle transition slope 113. The slope of the transition slope 113 is 1:3 and the length of the transition area is 60μm. This allows the deformation of the corrugated part 11 to be smoothly transmitted to the flat part 12, avoiding sudden stress changes at the interface and improving the fatigue resistance of the implanted pressure sensor.

[0046] The radius of the fillet 112 at the transition between the crest and trough of the corrugated portion 11 is 8 μm. The radial reinforcing ribs 122 of the flat portion 12 correspond one-to-one with the five troughs of the corrugated portion 11. The width of the reinforcing ribs 122 is 15 μm, further optimizing the deformation transfer efficiency.

[0047] The implantable pressure sensor in this embodiment can be flexibly adapted to different implantation scenarios such as intracranial and vascular implantation by adjusting the ratio of wave distance to wave height. The combination design of transition slope 113 and reinforcing rib 122 significantly improves the service life of the implantable pressure sensor under long-term cyclic load.

[0048] Example 4: In this embodiment, as Figure 7 and Figure 8 As shown, the corrugated section 11 is a parallel corrugation extending in one direction, and the extension direction of the parallel corrugation is consistent with the sensor implantation direction (such as along the blood vessel axis). The wave pitch λ and wave height h of the corrugated section 11 satisfy λ=4h, and the wave height h is gradually set from 10μm to 20μm along the extension direction, with 6 cycles.

[0049] The radius of the fillet 112 at the transition between the crests and troughs of the corrugated portion 11 is 6 μm, and the connection between the corrugated portion 11 and the flat portion 12 is provided with a transition slope 113 of 1:3. This structure is suitable for scenarios where the implantation path is limited. The extension direction of the parallel corrugations is consistent with the implantation direction, which can reduce the scratching of surrounding tissues during implantation, while ensuring the accurate transmission of pressure along the implantation direction.

[0050] In the above embodiments, the concentric gradient distribution, asymmetric curve, reinforcing ribs, and flanged edges of the corrugated diaphragm 1 are all targeted optimizations of the corrugated structure, enabling the implantable pressure sensor to have a more uniform stress distribution, higher measurement accuracy, and longer service life in implantable scenarios. The gradient distribution and transition slope structure design of the corrugated part 11 effectively alleviates the stress concentration problem under dynamic pressure. The radial reinforcing ribs 122 and the annular positioning groove 121 improve the assembly accuracy and deformation transmission stability of the sensor, adapting to the usage requirements of different implantation scenarios.

[0051] The above description is merely a preferred embodiment of the present invention and the technical principles employed. The present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions that can be made by those skilled in the art will not depart from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention.

Claims

1. An implantable pressure sensor based on a corrugated structure optimization, characterized in that, include: A corrugated diaphragm, a pressure-sensitive diaphragm, and a supporting base; the corrugated diaphragm is disposed on the upper side of the pressure-sensitive diaphragm; the pressure-sensitive diaphragm is disposed on the upper side of the supporting base, and a pressure-sensitive cavity is provided between the two; The corrugated diaphragm includes an integrally formed corrugated portion and a flat portion. The corrugated portion is a pressure-sensitive portion, and the flat portion is a joint portion and is attached to the pressure-sensitive diaphragm. The cross-sectional curve of the corrugated part is a periodic sine curve, and the corrugated part is distributed in a concentric gradient.

2. The implantable pressure sensor as described in claim 1, characterized in that, The wave pitch λ and wave height h of the corrugated part satisfy λ=3h~5h, and the wave height h is gradually set from the center of the corrugated part to the edge of 10μm~20μm.

3. The implantable pressure sensor as described in claim 2, characterized in that, When the implantable pressure sensor is adapted for intracranial pressure measurement, the wave distance λ of the corrugated part is 3h; when the implantable pressure sensor is adapted for vascular pressure measurement, the wave distance λ of the corrugated part is 5h.

4. The implantable pressure sensor as described in claim 2, characterized in that, The number of cycles in the corrugated section is 3 to 8, and the number of cycles increases from the inside to the outside along the radial direction of the corrugated section.

5. The implantable pressure sensor as described in claim 1, characterized in that, The corrugated section has transition fillets at both the crests and troughs, and the radius of the transition fillets is ≥5μm.

6. The implantable pressure sensor as described in claim 1, characterized in that, The connection between the corrugated part and the flat part is provided with a gentle transition slope, the slope of which is 1:

3.

7. The implantable pressure sensor as described in claim 1, characterized in that, The flat portion is provided with an annular positioning groove on the side away from the corrugated portion, and the annular positioning groove is adapted to engage with the edge of the pressure-sensitive diaphragm.

8. The implantable pressure sensor as described in claim 1, characterized in that, The flat portion has radial reinforcing ribs on the side facing the pressure-sensitive diaphragm. The reinforcing ribs extend radially along the corrugated portion and correspond one-to-one with the troughs of the corrugated portion.

9. The implantable pressure sensor as described in claim 1, characterized in that, The cross-sectional sinusoidal curve of the corrugated part is asymmetrically arranged, with the arc length of the rising edge of the corrugated part being greater than the arc length of the falling edge, and the radius of curvature of the rising edge being smaller than the radius of curvature of the falling edge.

10. The implantable pressure sensor as described in claim 1, characterized in that, The outer edge of the corrugated portion is provided with a smooth flange that slopes outward. The flange transitions to the upper surface of the flat portion at an obtuse angle, and the outer surface of the flange smoothly connects to the trough surface of the corrugated portion.

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