A disposable lens sheath for laparoscopy and its optimization method

Abstract

The present invention relates to a disposable lens sheath for a laparoscope and an optimization method thereof, including a rubber lens sheath cover and a sheath head. The length of the rubber lens sheath cover is less than the length of the laparoscope rod. One end of the rubber lens sheath cover is hermetically connected to the sheath head, and the sheath head is provided with a transparent lens adapted to the end cross-section of the laparoscope rod. The other end of the rubber lens sheath cover is open, and the inner diameter of the rubber lens sheath cover is less than the outer diameter of the laparoscope rod. The laparoscope rod can be inserted into the rubber lens sheath cover through the open end of the rubber lens sheath cover so that the end of the laparoscope rod abuts against the transparent lens.

Description

Technical Field

[0001] The present invention relates to the technology of medical devices, in particular to a disposable lens sheath for laparoscopy and an optimization method thereof. Background Art

[0002] As medical devices, laparoscopes and endoscopes need to insert the lens into the human body cavity during use and need to be disinfected before each use; when using the high-temperature and high-pressure sterilization method for disinfection, the high-temperature and high-pressure steam will cause the components of the endoscope to expand due to heat, resulting in the failure of the endoscope seal. The high-temperature steam will leak between the lens groups, resulting in a decrease in the image imaging quality, and seriously, it will cause the lens to be scrapped.

[0003] For example, the "medical endoscope capable of being repeatedly sterilized by high temperature and high pressure" disclosed in the Chinese patent document with the publication number CN106264428A includes a thin-walled endoscope catheter, a lighting unit, a lens group unit, a camera unit, and a video processing unit. The lighting unit, the lens group unit, and the camera unit are tightly bonded to the inner wall of the endoscope catheter through a high-temperature-resistant epoxy resin; it can be sterilized by high temperature and high pressure, realizing the repeated use of the endoscope system. For example, the "3D imaging endoscope capable of being repeatedly disinfected by high temperature and high pressure" disclosed in the Chinese patent document with the application number 202310794758.6 includes a lens body, a housing, and a lens. One end of the housing is connected to the lens body, and the other end is connected to the lens. The lens body is also provided with an optical fiber connector. The outer side of the lens is provided with an inclined surface, and a compression spring can tightly press the head of the imaging lens tube against the lens, so that the imaging lens tube is reliably installed and positioned in the lens body and the housing.

[0004] Although the endoscopes disclosed in the above patent documents reduce the impact of high-temperature disinfection and sterilization on the endoscope and improve the service life of the endoscope, there are still problems of incomplete disinfection leading to cross-infection and high use costs. Summary of the Invention

[0005] The purpose of the present invention is to provide a disposable lens sheath for laparoscopy and an optimization method thereof to solve the problems of incomplete disinfection and high use costs in the prior art.

[0006] To solve the above problems, the present invention provides a disposable lens sheath for laparoscopy, including a rubber lens sheath cover and a sheath head. The length of the rubber lens sheath cover is less than the length of the laparoscope rod. One end of the rubber lens sheath cover is hermetically connected to the sheath head, and the sheath head is provided with a transparent lens adapted to the end cross-section of the laparoscope rod; the other end of the rubber lens sheath cover is open, the inner diameter of the rubber lens sheath cover is less than the outer diameter of the laparoscope rod, and the laparoscope rod can be inserted into the rubber lens sheath cover through the open end of the rubber lens sheath cover so that the end of the laparoscope rod abuts against the transparent lens.

[0007] One disposable lens sheath for laparoscope provided by the present invention further has the following technical features:

[0008] Further, the outer diameter of the laparoscope rod = the inner diameter of the rubber lens sheath + d, and 1mm ≤ d ≤ 3mm.

[0009] Further, d = 2mm.

[0010] Further, before the laparoscope rod is inserted into the rubber lens sheath, a predetermined amount of physiological saline is injected into the rubber lens sheath through the open end of the rubber lens sheath to lubricate the inner wall of the rubber lens sheath.

[0011] Further, after the laparoscope rod is inserted into the rubber lens sheath, a 3mm to 15mm interval filled with the physiological saline is formed between the end of the laparoscope rod and the transparent lens.

[0012] Further, after the laparoscope rod is inserted into the rubber lens sheath, a 4mm to 10mm interval filled with the physiological saline is formed between the end of the laparoscope rod and the transparent lens.

[0013] The present invention also provides an optimization method for the disposable lens sheath for laparoscope, which calculates the deformation stress of rubber lens sheaths with different thicknesses to determine a suitable thickness of the rubber lens sheath, including the steps:

[0014] S10. Determine the outer diameter of the laparoscope rod and the inner diameter of the rubber lens sheath, and calculate the radial deformation amount of the rubber lens sheath after the laparoscope rod is inserted into the rubber lens sheath;

[0015] S20. According to the inner diameter of the rubber lens sheath and the radial deformation amount of the rubber lens sheath, use the hyperelastic model Neo-Hookean of nonlinear finite element analysis to calculate the maximum equivalent stress and the maximum equivalent elastic strain of the rubber lens sheaths with different thicknesses after deformation;

[0016] S30. Take the lens sheath thickness with the minimum maximum equivalent stress and the minimum maximum equivalent elastic strain after the deformation of the rubber lens sheath as the preferred lens sheath thickness.

[0017] Further, in the step S10, the outer diameter of the laparoscope rod is 10mm, the inner diameter of the rubber lens sheath is 8mm, and the radial deformation amount of the rubber lens sheath after the laparoscope rod is inserted into the rubber lens sheath is 1mm.

[0018] Further, it further includes step S40 of determining the length L of the laparoscopic rod wrapped by the rubber sheath after the laparoscopic rod is inserted into the rubber sheath, and verifying the acting force F (pull) for the rubber sheath to disengage from the laparoscopic rod according to the maximum equivalent stress σ corresponding to the preferred sheath thickness, the friction coefficient μ, the outer diameter D of the laparoscopic rod, and the length L of the laparoscopic rod wrapped by the rubber sheath.

[0019] Further, in step S40, F (pull) ≥ μ * σ * π * D * L.

[0020] The present invention has the following beneficial effects: For the disposable sheath for a laparoscope in this application, when using a laparoscope, the laparoscopic rod is inserted into the rubber sheath through the open end of the rubber sheath, and the end of the laparoscopic rod abuts against the transparent lens of the sheath head, and the transparent lens does not block the field of view at the end of the laparoscope; the laparoscopic rod is completely wrapped by the rubber sheath and does not contact the human body. After using the laparoscope, only this disposable sheath needs to be replaced, which can effectively avoid cross-infection caused by incomplete disinfection and sterilization of the laparoscope; it can effectively reduce the number of high-temperature and high-pressure disinfections and sterilizations of the laparoscope, improve the service life of the laparoscope, and reduce the use cost of the laparoscope; the rubber sheath made of rubber material has better affinity with the human body and can avoid the discomfort caused by the cold feeling when the metal laparoscopic rod contacts the patient's skin. Description of the Drawings

[0021] Figure 1 It is a structural schematic diagram of an existing laparoscope and endoscope;

[0022] Figure 2 It is a structural schematic diagram of the disposable sheath for a laparoscope according to an embodiment of the present invention;

[0023] Figure 3 It is another structural schematic diagram of the disposable sheath for a laparoscope according to an embodiment of the present invention;

[0024] Figure 4 It is for Figure 2 the structural schematic diagram when the disposable sheath for a laparoscope in

[0025] Figure 5 It is for Figure 3 the structural schematic diagram when the disposable sheath for a laparoscope in

[0026] Figure 6 It is the calculated values of the maximum equivalent stress and the maximum equivalent elastic strain corresponding to different sheath thicknesses;

[0027] Figure 7 It is a broken line graph of the relationship between the maximum equivalent stress and the sheath thickness;

[0028] Figure 8 It is a broken line graph showing the relationship between the maximum elastic strain and the thickness of the mirror sheath;

[0029] Figure 9 It is the distribution diagram of the equivalent elastic strain after the expansion deformation of the rubber mirror sheath when the thickness of the mirror sheath is 0.05mm;

[0030] Figure 10 It is the distribution diagram of the equivalent stress after the expansion deformation of the rubber mirror sheath when the thickness of the mirror sheath is 0.05mm;

[0031] Figure 11 It is the distribution diagram of the equivalent elastic strain after the expansion deformation of the rubber mirror sheath when the thickness of the mirror sheath is 0.10mm;

[0032] Figure 12 It is the distribution diagram of the equivalent stress after the expansion deformation of the rubber mirror sheath when the thickness of the mirror sheath is 0.10mm;

[0033] Figure 13 It is the distribution diagram of the equivalent elastic strain after the expansion deformation of the rubber mirror sheath when the thickness of the mirror sheath is 0.15mm;

[0034] Figure 14 It is the distribution diagram of the equivalent stress after the expansion deformation of the rubber mirror sheath when the thickness of the mirror sheath is 0.15mm;

[0035] Figure 15 It is the distribution diagram of the equivalent elastic strain after the expansion deformation of the rubber mirror sheath when the thickness of the mirror sheath is 0.20mm;

[0036] Figure 16 It is the distribution diagram of the equivalent stress after the expansion deformation of the rubber mirror sheath when the thickness of the mirror sheath is 0.20mm;

[0037] Figure 17 It is the distribution diagram of the equivalent elastic strain after the expansion deformation of the rubber mirror sheath when the thickness of the mirror sheath is 0.25mm;

[0038] Figure 18 It is the distribution diagram of the equivalent stress after the expansion deformation of the rubber mirror sheath when the thickness of the mirror sheath is 0.25mm;

[0039] Figure 19 It is the distribution diagram of the equivalent elastic strain after the expansion deformation of the rubber mirror sheath when the thickness of the mirror sheath is 0.30mm;

[0040] Figure 20 It is the distribution diagram of the equivalent stress after the expansion deformation of the rubber mirror sheath when the thickness of the mirror sheath is 0.35mm;

[0041] Figure 21 It is the schematic diagram of the static force between the rubber mirror sheath and the laparoscope rod, and the schematic diagram of the force when the rubber mirror sheath detaches from the laparoscope rod. Specific implementation method

[0042] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0043] As Figure 1 shown in the structural schematic diagram of the existing laparoscope and endoscope, the existing laparoscope and endoscope generally include

[0044] a lens body 101, a laparoscope rod 102 and a lens 103. One end of the laparoscope rod 102 is connected to the lens body 101, and the other end is connected to the lens 103. A fiber optic connector 104 is further provided on the lens body 101, and an inclined surface is provided on the outer side of the lens 103.

[0045] As Figures 2 to 3 shown in the embodiment of the disposable lens sheath for a laparoscope of the present invention, the disposable lens sheath for a laparoscope includes a rubber lens sheath sleeve 10 and a sheath head 20. The length of the rubber lens sheath sleeve 10 is less than the length of the laparoscope rod 102. One end of the rubber lens sheath sleeve 10 is hermetically connected to the sheath head 20, and the sheath head 20 is provided with a transparent lens adapted to the end face of the lens 103 at the end of the laparoscope rod 102; the other end of the rubber lens sheath sleeve 10 is open, and the inner diameter of the rubber lens sheath sleeve 10 is less than the outer diameter of the laparoscope rod 102. The laparoscope rod 102 can be inserted into the rubber lens sheath sleeve 10 through the open end of the rubber lens sheath sleeve, and the end of the laparoscope rod 102 abuts against the transparent lens. Preferably, the material of the rubber lens sheath sleeve 10 is silica gel; the inner diameter of the sheath head 20 is equal to the outer diameter of the laparoscope rod 102, and a connecting transition section is further provided at the end of the rubber lens sheath sleeve 10 connected to the sheath head 20, and the length of the connecting transition section is preferably 8 mm to 20 mm; the transparent lens of the sheath head is preferably made of glass.

[0046] For the disposable lens sheath for a laparoscope of the present application, when using a laparoscope, the laparoscope rod is inserted into the rubber lens sheath sleeve through the open end of the rubber lens sheath sleeve, and the end of the laparoscope rod abuts against the transparent lens of the sheath head. The transparent lens does not block the field of view at the end of the laparoscope; the laparoscope rod is completely wrapped by the rubber lens sheath sleeve and does not contact the human body. After the laparoscope is used, only this disposable lens sheath needs to be replaced, which can effectively avoid cross-infection caused by incomplete disinfection and sterilization of the laparoscope; it can effectively reduce the number of high-temperature and high-pressure disinfection and sterilization of the laparoscope, improve the service life of the laparoscope, and reduce the use cost of the laparoscope; the rubber lens sheath sleeve made of rubber has better affinity with the human body and can avoid the discomfort caused by the cold feeling when the metal laparoscope rod contacts the patient's skin.

[0047] In an embodiment of the present application, preferably, the outer diameter of the laparoscope rod = the inner diameter of the rubber sheath + d, where 1 mm ≤ d ≤ 3 mm, and preferably, d = 2 mm. When designed with such structural dimensions, after the laparoscope rod is inserted into the rubber sheath, the inner diameter of the rubber sheath expands radially by 2 mm, so that the resistance is small when the laparoscope rod is inserted into the rubber sheath, and after the laparoscope rod is inserted into the rubber sheath, it is tightly combined with the laparoscope rod and not easy to separate.

[0048] In an embodiment of the present application, preferably, before the laparoscope rod 102 is inserted into the rubber sheath 10, a predetermined amount of physiological saline is injected into the rubber sheath 10 through the open end of the rubber sheath 10 to lubricate the inner wall of the rubber sheath 10, thereby reducing the resistance when the laparoscope rod is inserted into the rubber sheath and facilitating the insertion of the laparoscope rod into the rubber sheath. Preferably, as Figure 4 、 Figure 5 shown, after the laparoscope rod 102 is inserted into the rubber sheath 10, a 3 mm to 15 mm interval 105 filled with physiological saline is formed between the end of the laparoscope rod 102 and the transparent lens of the sheath head 20; by setting the interval 105 and filling it with physiological saline, the cleanliness of the lens at the front end of the laparoscope rod 102 and the transparent lens of the sheath head 20 can be improved, making the laparoscope vision clear; it can also avoid hard contact between the lens at the front end of the laparoscope rod 102 and the transparent lens of the sheath head 20 and reduce wear.

[0049] In an embodiment of the present application, preferably, after the laparoscope rod 102 is inserted into the rubber sheath 10, a 4 mm to 10 mm interval 105 filled with physiological saline is formed between the end of the laparoscope rod 102 and the transparent lens of the sheath head 20.

[0050] The present invention also provides a method for optimizing a disposable sheath for a laparoscope, which calculates the deformation stress of rubber sheaths with different thicknesses to determine the preferred sheath thickness, including the steps of:

[0051] S10, determining the outer diameter of the laparoscope rod and the inner diameter of the rubber sheath, and calculating the radial deformation amount of the rubber sheath after the laparoscope rod is inserted into the rubber sheath;

[0052] S20, according to the inner diameter of the rubber sheath and the radial deformation amount of the rubber sheath, using the hyperelastic model Neo-Hookean of nonlinear finite element analysis to calculate the maximum equivalent stress and maximum equivalent elastic strain after deformation of rubber sheaths with different thicknesses;

[0053] S30, taking the sheath thickness with the minimum maximum equivalent stress and minimum maximum equivalent elastic strain after deformation of the rubber sheath as the preferred sheath thickness.

[0054] In the above-mentioned disposable trocar optimization method for laparoscopy, preferably, in step S10, the outer diameter of the laparoscope rod is 10 mm, the inner diameter of the rubber trocar sheath is 8 mm, and the radial deformation of the rubber trocar sheath after the laparoscope rod is inserted into the rubber trocar sheath is 1 mm.

[0055] Specifically, the Neo-Hookean model was proposed by the British mechanic Ronald Rivlin (1915 - 2005) in 1948. In this application, the hyperelastic model Neo-Hookean of nonlinear finite element analysis is used. To simplify the calculation, it is assumed that the silicone material of the rubber trocar sheath is an incompressible material. At this time, the Neo-Hookean model is a steady shear model, which can be used to approximately predict the mechanical behavior of rubber under 30% - 40% uniaxial tension and 80% - 90% pure shear. It is used for the deformation analysis of the rubber trocar sheath in this application, with simple settings, strong versatility, and small calculation amount.

[0056] As described above, in this application, the outer diameter of the laparoscope rod is 10 mm, the inner diameter of the rubber trocar sheath is 8 mm, and the radial deformation of the rubber trocar sheath after the laparoscope rod is inserted into the rubber trocar sheath is 1 mm; the maximum equivalent stress and maximum equivalent elastic strain after the deformation of the rubber trocar sheath are calculated by using the hyperelastic model Neo-Hookean of nonlinear finite element analysis when the trocar sheath thickness is 0.05 mm, 0.10 mm, 0.15 mm, 0.20 mm, 0.25 mm, and 0.30 mm. The calculation results are as Figure 6 shown; the broken line graph of the relationship between the maximum equivalent stress and the trocar sheath thickness is as Figure 7 shown, and the broken line graph of the relationship between the maximum elastic strain and the trocar sheath thickness is as Figure 8 shown. It can be Figure 6 , Figure 7 , Figure 8 seen that when the thickness of the rubber trocar sheath is 0.15 mm, the maximum equivalent stress and the maximum equivalent elastic strain after deformation are the smallest. Therefore, the preferred trocar sheath thickness is determined to be 0.15 mm.

[0057] In the above-mentioned disposable trocar optimization method for laparoscopy, preferably, it further includes step S40 of determining the length L of the laparoscope rod wrapped by the rubber trocar sheath after the laparoscope rod is inserted into the rubber trocar sheath, and verifying the acting force F (pull) for the rubber trocar sheath to disengage from the laparoscope rod according to the maximum equivalent stress σ, friction coefficient μ, outer diameter D of the laparoscope rod, and the length L of the laparoscope rod wrapped by the rubber trocar sheath corresponding to the preferred trocar sheath thickness. Preferably, in step S40, F (pull) ≥ μ * σ * π * D * L.

[0058] In the above-mentioned disposable mirror sheath optimization method for laparoscopy, for example: the outer diameter D of the laparoscope rod is 10 mm, the inner diameter of the rubber mirror sheath is 8 mm, and the radial deformation of the rubber mirror sheath after the laparoscope rod is inserted into the rubber mirror sheath is 1 mm; if the preferred mirror sheath thickness is determined to be 0.15 mm, the corresponding maximum equivalent stress σ is 0.020639 MPa; the material of the rubber mirror sheath is silica gel, and generally μ = 0.05 - 0.3, and μ = 0.1 is selected; the length L of the laparoscope rod 102 wrapped by the rubber mirror sheath 10 is 300 mm; as Figure 21 The static force diagram between the rubber mirror sheath and the laparoscope rod and the force diagram when the rubber mirror sheath disengages from the laparoscope rod are shown. F is the pressure exerted on the laparoscope rod, F N is the supporting force of the rubber mirror sheath after being subjected to pressure. The two are equal. When it is necessary to peel off the rubber mirror sheath, a certain amount of force F (pull) needs to be used to slowly remove the rubber mirror sheath. F (pull) needs to be greater than or equal to the friction force f between the rubber mirror sheath and the laparoscope rod,

[0059] where the friction force f = μ * F N ,

[0060] F N = F N = F =σ *S ,

[0061] where, S is the force-bearing area, S =π * D * L ,

[0062] Summarizing the above, F (pull) ≥ μ * σ * π * D * L;

[0063] In this embodiment of the present application,

[0064] μ * σ * π * D * L = 0.1 * 0.020639 MPa * 3.14 * 10 mm * 300 mm = 19.5 N;

[0065] That is, F (pull) ≥ 19.5 N, within a reasonable range.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A disposable mirror sheath optimization method for laparoscopy, characterized in that: Calculate the deformation stress of rubber mirror sheath covers with different thicknesses to determine the preferred mirror sheath thickness, including the steps of: S10, determine the outer diameter of the laparoscope rod and the inner diameter of the rubber mirror sheath cover, and calculate the radial deformation amount of the rubber mirror sheath cover after the laparoscope rod is inserted into the rubber mirror sheath cover; S20, according to the inner diameter of the rubber mirror sheath cover and the radial deformation amount of the rubber mirror sheath cover, use the hyperelastic model Neo-Hookean of nonlinear finite element analysis to calculate the maximum equivalent stress and the maximum equivalent elastic strain after deformation of the rubber mirror sheath cover with different thicknesses; S30, take the mirror sheath thickness with the minimum maximum equivalent stress and the minimum maximum equivalent elastic strain after deformation of the rubber mirror sheath cover as the preferred mirror sheath thickness.

2. The optimized method for disposable sheath according to claim 1, wherein: In step S10, the outer diameter of the laparoscope rod is 10 mm, the inner diameter of the rubber mirror sheath cover is 8 mm, and the radial deformation amount of the rubber mirror sheath cover after the laparoscope rod is inserted into the rubber mirror sheath cover is 1 mm.

3. The disposable sheath optimization method according to claim 1, wherein: It further includes step S40, determine the length L of the laparoscope rod wrapped by the rubber mirror sheath cover after the laparoscope rod is inserted into the rubber mirror sheath cover, and verify the acting force F (pull) for the rubber mirror sheath cover to separate from the laparoscope rod according to the maximum equivalent stress σ corresponding to the preferred mirror sheath thickness, the friction coefficient μ, the outer diameter D of the laparoscope rod, and the length L of the laparoscope rod wrapped by the rubber mirror sheath cover.

4. The disposable sheath optimization method according to claim 3, wherein: In step S40, F (pull) ≥ μ * σ * π * D * L.

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