Periodontal pocket depth measurement device

Abstract

The present invention discloses a periodontal pocket depth measurement device. The device comprises: a laser transceiver control unit for generating original laser light; a probe having a detection end for probing into the bottom of the periodontal pocket; an integrated optical fiber probe arranged on the probe and connected to the laser transceiver control unit for converting the original laser light into a collimated line laser light, and converting part of the collimated line laser light into a measuring laser light and part of it into a reference laser light, the integrated optical fiber probe also being used to emit the measuring laser light to the detection end of the probe and reflect the reference laser light back to the laser transceiver control unit; an elastic membrane arranged at the end of the detection end of the probe and spaced apart from the integrated optical fiber probe for forming an interference laser light; the laser transceiver control unit is connected to a host computer and is also used to transmit the information of the reference laser light and the interference laser light to the host computer to calculate the depth of the periodontal pocket. The present invention solves the problem of large errors in the current manual measurement of the depth of the periodontal pocket.

Description

Technical Field

[0001] The present invention relates to the field of oral medical instruments, and in particular to a device for measuring the depth of a periodontal pocket. Background Art

[0002] Periodontal probing is an important method for basic oral health diagnosis. The measurement results of periodontal pocket depth and attachment level are currently the main methods for clinical evaluation of the degree of periodontal damage, and are also the clinical basis for judging changes in periodontal disease.

[0003] The results of periodontal pocket depth measurement are affected by many factors, such as the design of the probe used for measurement, the force used by the operator, tactile errors, and reading errors of the measurement results.

[0004] At present, the periodontal pocket depth is mainly measured by traditional manual measurement. The manual measurement process takes a long time, about 30 minutes, and requires at least two doctors to work together at the same time, which is time-consuming and labor-intensive, and the measurement results are prone to errors.

[0005] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0006] The embodiment of the present invention provides a periodontal pocket depth measurement device to at least solve the technical problem of large errors in the current manual periodontal pocket depth measurement.

[0007] According to one aspect of an embodiment of the present invention, a periodontal pocket depth measurement device is provided, the device comprising: a laser transceiver control unit for generating original laser light; a probe having a detection end for probing into the bottom of the periodontal pocket; an integrated fiber optic probe disposed on the probe and connected to the laser transceiver control unit, for converting the original laser light generated by the laser transceiver unit into collimated laser light, and converting a part of the collimated laser light into a measuring laser light and another part into a reference laser light, the integrated fiber optic probe being further configured to emit the measuring laser light to the detection end of the probe along an extension direction of the probe and to reflect the reference laser light back to the laser transceiver control unit; an elastic membrane disposed at the end of the detection end of the probe and spaced apart from the integrated fiber optic probe, for reflecting and / or scattering the measuring laser light to the integrated fiber optic probe to form an interference laser light; wherein the laser transceiver control unit is connected to a host computer, the laser transceiver control unit being further configured to receive the reference laser light and the interference laser light and to transmit information of the reference laser light and the interference laser light to the host computer to calculate the depth of the periodontal pocket.

[0008] Furthermore, the laser transceiver control unit includes: a tunable laser for generating the original laser; a control and signal processing unit connected to the tunable laser for controlling the working process of the tunable laser.

[0009] Furthermore, the laser transceiver control unit also includes: a photodetector, connected to the control and signal processing unit, for receiving the reference laser and the interference laser; wherein the control and signal processing unit is also used to control the working process of the tunable laser, and process the information of the reference laser and the interference laser and transmit it to the host computer.

[0010] Furthermore, the laser transceiver control unit further includes: an optical fiber splitter connected to both the tunable laser and the photodetector, for splitting the original laser generated by the tunable laser and the reference laser and interference laser received by the photodetector.

[0011] Furthermore, the above-mentioned integrated fiber optic probe includes: a lens component, which is used to convert the above-mentioned original laser generated by the above-mentioned laser transceiver unit into a collimated linear laser; wherein the above-mentioned lens component has a reference surface, a part of the above-mentioned collimated linear laser is transformed into the above-mentioned measurement laser after being transmitted through the above-mentioned reference surface, and another part of the above-mentioned collimated linear laser is transformed into the above-mentioned reference laser after being reflected through the above-mentioned reference surface.

[0012] Furthermore, the periodontal pocket depth measuring device also includes: a handle body, the laser transceiver control unit is arranged in the handle body; a spring sheet, one end of the spring sheet is connected to the handle body; wherein the probe also has a connecting end, the connecting end is an end opposite to the detection end, and the connecting end is connected to the other end of the spring sheet so that when the spring sheet is subjected to external force, the probe moves relative to the handle body along its extension direction.

[0013] Furthermore, the periodontal pocket depth measuring device further comprises: a connecting frame, through which the integrated optical fiber probe is connected to the handle body, and the integrated optical fiber probe and the probe can be relatively slidably arranged to remain stationary when the probe moves.

[0014] Furthermore, the periodontal pocket depth measuring device further comprises: a single-mode optical fiber, and the integrated optical fiber probe is connected to the laser transceiver control unit via the single-mode optical fiber.

[0015] Furthermore, the probe is a hollow tube structure, the inside of the probe has a hollow cavity extending along the extension direction of the probe, and the measuring laser is transmitted along the hollow cavity.

[0016] Furthermore, the end of the detection end of the probe has an opening communicating with the hollow cavity, and the elastic membrane is arranged on the opening of the detection end.

[0017] In an embodiment of the present invention, the periodontal pocket depth measuring device includes: a laser transceiver control unit, which is used to generate original laser; a probe, the probe has a detection end, and the detection end is used to probe into the bottom of the periodontal pocket; an integrated fiber optic probe, which is arranged on the probe and connected to the laser transceiver control unit, and is used to convert the original laser generated by the laser transceiver unit into a collimated linear laser, and convert a part of the collimated linear laser into a measuring laser and another part into a reference laser. The integrated fiber optic probe is also used to emit the measuring laser to the detection end of the probe along the extension direction of the probe and reflect the reference laser back to the laser transceiver control unit; an elastic membrane, which is arranged at the end of the detection end of the probe and is spaced apart from the integrated fiber optic probe, and is used to reflect and / or scatter the measuring laser to the integrated fiber optic probe to form an interference laser; wherein the laser transceiver control unit is connected to a host computer, and the laser transceiver control unit is also used to receive the reference laser and the interference laser and transmit the information of the reference laser and the interference laser to the host computer to calculate the depth of the periodontal pocket. The periodontal pocket depth measurement device in the embodiment of the present invention has a simple structure and is easy to operate, achieving the technical effect of improving the measurement accuracy and efficiency of periodontal pocket depth measurement, thereby solving the technical problem of large errors in the current manual periodontal pocket depth measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 is a schematic structural diagram of an optional periodontal pocket depth measuring device according to an embodiment of the present invention;

[0020] Figure 2 is a schematic structural diagram of an optional laser transceiver control unit according to an embodiment of the present invention;

[0021] Figure 3 is a schematic structural diagram of an optional integrated optical fiber probe according to an embodiment of the present invention;

[0022] The above drawings include the following reference numerals:

[0023] 10. Laser transceiver control unit; 11. Tunable laser; 12. Photodetector; 13. Fiber optic splitter; 14. Control and signal processing unit; 101. Measuring switch; 102. Power supply and USB interface; 103. Measuring laser; 104. Interference laser; 20. Probe; 30. Integrated fiber optic probe; 31. Lens component; 32. Reference surface; 40. Elastic membrane; 50. Host computer; 60. Handle body; 70. Spring sheet; 80. Connecting frame; 90. Single-mode optical fiber. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0025] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0026] According to an embodiment of the present invention, a structural embodiment of a periodontal pocket depth measuring device is provided.

[0027] Figure 1 is a schematic structural diagram of an optional periodontal pocket depth measuring device according to an embodiment of the present invention. Figure 1 As shown, the periodontal pocket depth measuring device comprises: a laser transceiver control unit (10) for generating original laser light; a probe (20), wherein the probe (20) has a detection end, and the detection end is used to detect the bottom of the periodontal pocket; an integrated optical fiber probe (30), which is arranged on the probe (20) and connected to the laser transceiver control unit (10), and is used to convert the original laser light generated by the laser transceiver unit (10) into collimated linear laser light, and convert a part of the collimated linear laser light into measurement laser light, and another part of the collimated linear laser light into reference laser light. The integrated optical fiber probe (30) is also used to convert the measurement laser light into reference laser light along the extension direction of the probe (20). The laser transceiver control unit (10) is configured to emit the reference laser to the detection end of the probe (20) and reflect the reference laser back to the laser transceiver control unit (10); the elastic membrane (40) is arranged at the end of the detection end of the probe (20) and is spaced apart from the integrated optical fiber probe (30), and is used to reflect and / or scatter the measurement laser to the integrated optical fiber probe (30) to form an interference laser; wherein the laser transceiver control unit (10) is connected to the host computer (50), and the laser transceiver control unit (10) is also used to receive the reference laser and the interference laser and transmit the information of the reference laser and the interference laser to the host computer (50) to calculate the depth of the periodontal pocket.

[0028] In an embodiment of the present invention, the periodontal pocket depth measuring device includes: a laser transceiver control unit, which is used to generate original laser; a probe, the probe has a detection end, and the detection end is used to probe into the bottom of the periodontal pocket; an integrated fiber optic probe, which is arranged on the probe and connected to the laser transceiver control unit, and is used to convert the original laser generated by the laser transceiver unit into a collimated linear laser, and convert a part of the collimated linear laser into a measuring laser and another part into a reference laser. The integrated fiber optic probe is also used to emit the measuring laser to the detection end of the probe along the extension direction of the probe and reflect the reference laser back to the laser transceiver control unit; an elastic membrane, which is arranged at the end of the detection end of the probe and is spaced apart from the integrated fiber optic probe, and is used to reflect and / or scatter the measuring laser to the integrated fiber optic probe to form an interference laser; wherein the laser transceiver control unit is connected to a host computer, and the laser transceiver control unit is also used to receive the reference laser and the interference laser and transmit the information of the reference laser and the interference laser to the host computer to calculate the depth of the periodontal pocket. The periodontal pocket depth measurement device in the embodiment of the present invention has a simple structure and is easy to operate, achieving the technical effect of improving the measurement accuracy and efficiency of periodontal pocket depth measurement, thereby solving the technical problem of large errors in the current manual periodontal pocket depth measurement.

[0029] Optionally, the periodontal pocket depth measurement device in the embodiment of the present invention has a simple and sophisticated structure, and ensures high measurement accuracy based on the laser interference principle. Compared with the traditional manual measurement method, it effectively improves the periodontal pocket depth measurement accuracy and can be widely used in the basic diagnosis of oral diseases such as periodontology, orthodontics, implants and prosthodontics.

[0030] Optionally, the probe (20) is a hollow tube made of titanium metal material. The probe (20) can be divided into a probe upper end and a probe lower end. The diameter of the probe lower end does not exceed 0.2 mm and has an opening. The opening is wrapped with an elastic membrane (40). The probe lower end and the probe upper end can be fastened and connected by an internal thread.

[0031] Alternatively, if Figure 1 As shown, the measurement switch (101) is used to start a depth measurement, and the power supply and USB interface (102) is used to control the power supply of the system and connect with the host computer (50).

[0032] Optionally, the elastic membrane (40) is adapted to reflect and scatter light to the distal end of the optical fiber, and the elastic membrane (40) is made of fluorinated ethylene propylene.

[0033] Optionally, the diameter of the integrated optical fiber probe (30) is generally no more than 1.8 mm. The integrated optical fiber probe (30) can slide up and down along the lower end of the probe (20).

[0034] Optionally, the laser transceiver control unit (10) is further used to receive the reference laser and the interference laser and transmit the information of the reference laser and the interference laser to the host computer (50) to calculate the depth of the periodontal pocket. The calculation process is as follows:

[0035] Assuming that the light intensities of the measuring laser and the reference laser are I1 and I2 respectively, the light intensity of the interference laser can be expressed by formula (1):

[0036]

[0037] in, and are the phases of the reference laser and the measurement laser respectively, then the phase difference between the two beams can be expressed by equation (2):

[0038]

[0039] Where: L is the optical path difference between the reference laser and the measurement laser, that is, twice the distance to be measured d; v is the optical frequency; c is the speed of light.

[0040] From equations (1) and (2), it can be seen that when the laser frequency v is linearly scanned without mode hopping, the interference light intensity signal I obtained by the photodetector is a periodic signal with a fixed frequency, and its frequency can be expressed by equation (3):

[0041]

[0042] Among them, Δv is the frequency scanning range, and Δt is the frequency scanning time.

[0043] From formula (3), we can know that after obtaining the frequency f of the interference signal, we can get the distance d to be measured:

[0044]

[0045] In summary, the distance d to be measured is the depth of the periodontal pocket calculated by the host computer (50).

[0046] Optionally, compared with the traditional manual measurement method, the present application has significant improvements in the structure and connection relationship of the measuring elements, is easy to operate, saves labor costs, and improves the measurement accuracy of the periodontal pocket depth.

[0047] Optionally, Figure 2 is a schematic diagram of the structure of an optional laser transceiver control unit according to an embodiment of the present invention, such as Figure 2 As shown, the laser transceiver control unit (10) comprises: a tunable laser (11) for generating original laser light; and a control and signal processing unit (14) connected to the tunable laser (11) for controlling the working process of the tunable laser (11).

[0048] Alternatively, if Figure 2 As shown, the laser transceiver control unit (10) also includes: a photodetector (12), which is connected to the control and signal processing unit (14) and is used to receive the reference laser and the interference laser; wherein the control and signal processing unit (14) is also used to control the working process of the tunable laser (11), and process the information of the reference laser and the interference laser and transmit it to the host computer (50).

[0049] Alternatively, if Figure 2 As shown, the laser transceiver control unit (10) further includes: an optical fiber splitter (13), which is connected to both the tunable laser (11) and the photodetector (12) and is used to split the original laser generated by the tunable laser (11) and the reference laser and interference laser received by the photodetector (12).

[0050] Optionally, the integrated optical fiber probe (30) includes a lens component (31) and a mechanical structure, and the mechanical structure is only used to fix the positions of the optical fiber and the lens component (31). The end face of the single-mode optical fiber (90) is fixed near the focal plane of the lens component (31), and the light emitted from the optical fiber core is converted into collimated light after passing through the lens component (31). One of the surfaces in the lens component (31) is made into a reference surface with a certain reflectivity. When the collimated light passes through the reference surface, part of the reflected light will be produced, and the reflected light will be coupled back into the optical fiber as the reference light (32). The remaining light will be reflected or scattered after reaching the elastic membrane (40) after passing through the probe (20). The part of the reflected or scattered light will be refocused after passing through the lens component (31) and coupled back into the optical fiber as the measuring light. The measuring light and the reference light will interfere in the optical fiber and be transmitted to the photodetector (12). The optical path difference can be calculated from the interference signal, and the optical path difference is the periodontal pocket depth to be measured.

[0051] Optionally, Figure 3 is a schematic diagram of the structure of an optional integrated optical fiber probe according to an embodiment of the present invention, such as Figure 3 As shown, the integrated optical fiber probe (30) includes: a lens component (31) for converting the original laser generated by the laser transceiver unit (10) into a collimated laser; wherein the lens component (31) has a reference surface (32), a part of the collimated laser is transmitted through the reference surface (32) and then converted into a measuring laser (103), and another part of the collimated laser is reflected through the reference surface (32) and then converted into a reference laser (104). It should be noted that the collimated laser is converted into two parallel collimated lights through the reference surface (32), thereby ensuring that the measuring laser (103) is a collimated laser.

[0052] Optionally, the periodontal pocket depth measuring device further comprises: a handle body (60), a laser transceiver control unit (10) being arranged in the handle body (60); a spring sheet (70), one end of which is connected to the handle body (60); wherein the probe (20) further comprises a connecting end, which is an end opposite to the detection end, and the connecting end is connected to the other end of the spring sheet (70) so that when the spring sheet (70) is subjected to an external force, the probe (20) moves relative to the handle body (60) along its extension direction. Specifically, the laser transceiver control unit (10) may be arranged in the cavity of the handle body (60).

[0053] Optionally, a spring sheet (70) is connected to the handle body (60), and the spring sheet (70) is used to generate a pressure of 10-15g on the probe (20).

[0054] Optionally, the periodontal pocket depth measuring device further comprises: a connecting frame (80), the integrated optical fiber probe (30) is connected to the handle body (60) via the connecting frame (80), and the integrated optical fiber probe (30) and the probe (20) are relatively slidably arranged so as to remain stationary when the probe (20) moves. The connecting frame (80) can ensure the mechanical stability of the integrated optical fiber probe (30).

[0055] Optionally, the periodontal pocket depth measuring device further comprises: a single-mode optical fiber (90), and the integrated optical fiber probe (30) is connected to the laser transceiver control unit (10) via the single-mode optical fiber (90). Specifically, one end of the single-mode optical fiber (90) is connected to the integrated optical fiber probe (30), and the other end is connected to the optical fiber splitter (13) in the laser transceiver control unit (10).

[0056] Optionally, the probe (20) is a hollow tube structure, and the probe (20) has a hollow cavity extending along the extension direction of the probe (20), and the measuring laser is transmitted along the hollow cavity.

[0057] Optionally, the end of the detection end of the probe (20) has an opening communicating with the hollow cavity, and the elastic membrane (40) is arranged on the opening of the detection end.

[0058] Optionally, in the process of using the periodontal pocket depth measuring device in the embodiment of the present invention, it is first necessary to connect the power supply and USB interface (102) to the power supply and the host computer (50), and the medical staff holds the handle body (60) with the right hand, and the right thumb can touch the measurement switch (101). The elastic membrane (40) is placed at the patient's periodontal pocket opening. At this time, the integrated optical fiber probe (30) and the elastic membrane (40) are at the same position, and the right index finger presses down the spring sheet (70), thereby generating a pressure of 10-15g. Under the pressure, the lower end of the probe (20) enters the patient's periodontal pocket. If the lower end of the probe (20) does not reach the detection position, the spring sheet (70) can be pressed again until the lower end of the probe (20) reaches the detection position. When the lower end of the probe (20) reaches the detection position, the right thumb presses the measurement switch (101), and at this time, the laser transceiver control unit (10) collects light interference information and transmits it to the host computer (50), and the depth of the patient's periodontal pocket can be obtained by calculating the reference light and the interference light. After all periodontal pockets of one patient have been detected, before detecting another patient, the lower end of the probe (20) can be twisted to replace the lower end of a new probe (20) (disposable), thereby preventing cross infection of oral diseases.

[0059] In an embodiment of the present invention, the periodontal pocket depth measuring device includes: a laser transceiver control unit, which is used to generate original laser; a probe, the probe has a detection end, and the detection end is used to probe into the bottom of the periodontal pocket; an integrated fiber optic probe, which is arranged on the probe and connected to the laser transceiver control unit, and is used to convert the original laser generated by the laser transceiver unit into a collimated linear laser, and convert a part of the collimated linear laser into a measuring laser and another part into a reference laser. The integrated fiber optic probe is also used to emit the measuring laser to the detection end of the probe along the extension direction of the probe and reflect the reference laser back to the laser transceiver control unit; an elastic membrane, which is arranged at the end of the detection end of the probe and is spaced apart from the integrated fiber optic probe, and is used to reflect and / or scatter the measuring laser to the integrated fiber optic probe to form an interference laser; wherein the laser transceiver control unit is connected to a host computer, and the laser transceiver control unit is also used to receive the reference laser and the interference laser and transmit the information of the reference laser and the interference laser to the host computer to calculate the depth of the periodontal pocket. The periodontal pocket depth measurement device in the embodiment of the present invention has a simple structure and is easy to operate, achieving the technical effect of improving the measurement accuracy and efficiency of periodontal pocket depth measurement, thereby solving the technical problem of large errors in the current manual periodontal pocket depth measurement.

[0060] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A periodontal pocket depth measuring device, characterized in that: include: A laser transceiver control unit (10), used for generating original laser light; A probe (20), the probe (20) having a detection end, the detection end being used to detect the bottom of the periodontal pocket; An integrated optical fiber probe (30) is arranged on the probe (20) and connected to the laser transceiver control unit (10), and is used to convert the original laser generated by the laser transceiver unit (10) into collimated linear laser, and to convert a part of the collimated linear laser into a measuring laser and another part into a reference laser. The integrated optical fiber probe (30) is also used to emit the measuring laser to the detection end of the probe (20) along the extension direction of the probe (30) and to reflect the reference laser back to the laser transceiver control unit (10); an elastic membrane (40), arranged at the end of the detection end of the probe (20) and spaced apart from the integrated optical fiber probe (30), and used for reflecting and / or scattering the measuring laser to the integrated optical fiber probe (30) to form interference laser; The laser transceiver control unit (10) is connected to a host computer (50), and the laser transceiver control unit (10) is also used to receive the reference laser and the interference laser and transmit information of the reference laser and the interference laser to the host computer (50) to calculate the depth of the periodontal pocket; The periodontal pocket depth measuring device also includes: A handle body (60), wherein the laser transceiver control unit (10) is arranged in the handle body (60); a spring sheet (70), one end of the spring sheet (70) being connected to the handle body (60); The probe (20) further comprises a connecting end, the connecting end being an end opposite to the detecting end, the connecting end being connected to the other end of the spring sheet (70) so that when the spring sheet (70) is acted upon by an external force, the probe (20) moves relative to the handle body (60) along its extension direction; The periodontal pocket depth measuring device also includes: A connecting frame (80), the integrated optical fiber probe (30) is connected to the handle body (60) via the connecting frame (80), and the integrated optical fiber probe (30) and the probe (20) are arranged to be relatively slidable so as to remain stationary when the probe (20) moves.

2. The periodontal pocket depth measuring device according to claim 1, characterized in that: The laser transceiver control unit (10) comprises: A tunable laser (11), used for generating the original laser; A control and signal processing unit (14) is connected to the tunable laser (11) and is used to control the working process of the tunable laser (11).

3. The periodontal pocket depth measuring device according to claim 2, characterized in that: The laser transceiver control unit (10) further comprises: A photodetector (12), connected to the control and signal processing unit (14), and used for receiving the reference laser and the interference laser; The control and signal processing unit (14) is also used to control the working process of the tunable laser (11), and to process the information of the reference laser and the interference laser and transmit it to the host computer (50).

4. The periodontal pocket depth measuring device according to claim 3, characterized in that: The laser transceiver control unit (10) further comprises: The optical fiber splitter (13) is connected to both the tunable laser (11) and the photodetector (12) and is used to split the original laser generated by the tunable laser (11) and the reference laser and interference laser received by the photodetector (12).

5. The periodontal pocket depth measuring device according to claim 1, characterized in that: The integrated optical fiber probe (30) comprises: A lens component (31) for converting the original laser light generated by the laser transceiver unit (10) into collimated linear laser light; The lens component (31) has a reference surface (32), a portion of the collimated line laser is transformed into the measuring laser after being transmitted through the reference surface (32), and another portion of the collimated line laser is transformed into the reference laser after being reflected through the reference surface (32).

6. The periodontal pocket depth measuring device according to claim 1, characterized in that: The periodontal pocket depth measuring device also includes: A single-mode optical fiber (90), wherein the integrated optical fiber probe (30) is connected to the laser transceiver control unit (10) via the single-mode optical fiber (90).

7. The periodontal pocket depth measuring device according to claim 1, characterized in that: The probe (20) is a hollow tube structure, and the inside of the probe (20) has a hollow cavity extending along the extension direction of the probe (20), and the measuring laser is transmitted along the hollow cavity.

8. The periodontal pocket depth measuring device according to claim 7, characterized in that: The end of the detection end of the probe (20) has an opening communicating with the hollow cavity, and the elastic membrane (40) is arranged on the opening of the detection end.

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