A novel asymmetric pneumatic endoscope device for achieving pre-bending

Abstract

This invention discloses a novel asymmetric pneumatic endoscope device for pre-bending, comprising: a housing with a diameter of 12 mm and a bending angle of 120° when stationary; a main body and rings disposed on the housing, the rings being connected to the main body, and sixteen rings being disposed; a reinforcing chamber disposed on the inner side of the main body; a driving chamber disposed between the reinforcing chamber and the housing; and a free central cavity disposed between the reinforcing chamber and the driving chamber. This device, by using a non-expandable housing for the pre-bending flexible endoscope, eliminates the need for a sheath to prevent radial expansion. Since the rings are connected to the main body running along the outer arc of the bending actuator, these rings are further apart along the outer arc and closer together along the inner arc. Therefore, when the actuator is compressed, the main body will inhibit the extension of the module, while the rings will limit radial expansion. The reinforced housing allows the endoscope to bend from a stationary position and straighten during the bending actuation.

Description

Technical Field

[0001] This invention relates to the field of endoscopy technology, and in particular to a novel asymmetric pneumatic endoscope device that achieves pre-bending. Background Art

[0002] Most minimally invasive surgeries require endoscopic visual feedback. Currently, commonly used endoscopes include rigid and flexible types. Rigid endoscopes, due to their limited movement, are difficult to safely move around healthy organs to the surgical target and are often used for surgical targets close to the incision point. Furthermore, their rigidity requires surgeons to apply additional force during surgery and can amplify camera tremors, resulting in unstable imaging. Flexible endoscopes offer the necessary maneuverability but lack the adjustable rigidity required for surgical procedures. Another disadvantage of flexible endoscopes is positioning; due to the lack of depth sensing and field of view stability, the camera cannot provide sufficient information to determine the position of the distal tip or other insertion tubes, making it difficult to track within the image. Flexible endoscopes are a rapidly developing research area, using flexible and compatible materials. This compatibility makes them ideal for endoscopes that require bending, deformation, and insertion depth without damaging their surroundings. Additionally, their inherent MRI compatibility, achieved through pneumatic actuation, allows for endoscope positioning during surgery.

[0003] Pneumatic bending actuators rely on the pressure within the chamber, resulting in the required actuation having radial expansion. Currently, advanced flexible pneumatic endoscopes are upright and encased in a sheath to prevent radial expansion. As the internal chamber is pressurized, the endoscope module bends from a straight position. However, since air must first fill the chamber before bending, the relationship between pneumatic pressure and bending is non-linear. Furthermore, its frictional interaction with the sheath triggers actuation behavior that affects the endoscope's performance. Traditional flexible endoscopes suffer from dead zones and non-linear actuation behavior, and this highly non-linear behavior leads to low actuator sensitivity, accuracy, and repeatability. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a novel asymmetric pneumatic endoscope device that achieves pre-bending, in order to solve the technical problem that in the prior art, soft pneumatic endoscopes need to be wrapped in a sheath to prevent radial expansion and that the relationship between pneumatic pressure and bending is nonlinear as the soft pneumatic endoscope bends from a straight line as the internal chamber is pressurized.

[0005] To achieve the above objectives, the present invention provides a novel asymmetric pneumatic endoscope device for pre-bending, comprising: a housing with a diameter of 12 mm and a bending angle of 120° when the housing is stationary; a main body and rings are provided on the housing, the rings being connected to the main body, and sixteen rings being provided; a reinforcing chamber is provided on the inner side of the main body; a driving chamber is provided between the reinforcing chamber and the housing; and a free central cavity is provided between the reinforcing chamber and the driving chamber.

[0006] Furthermore, the diameter of the free central cavity is 4.5 mm.

[0007] Furthermore, the cross-sectional area of ​​the reinforcing chamber is not greater than the cross-sectional area of ​​the driving chamber.

[0008] Furthermore, the cross-sectional area of ​​the drive chamber is half the cross-sectional area of ​​the endoscope.

[0009] Furthermore, the width of the main trunk is 1.5 mm.

[0010] Furthermore, the outer shell is not expandable.

[0011] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a novel asymmetric pneumatic endoscope device for pre-bending, which eliminates the need for a sheath to prevent radial expansion by setting a non-expandable shell for the pre-bending soft endoscope. Since the rings are connected to the main body running along the outer arc of the bending actuator, these rings are further apart along the outer arc and closer together along the inner arc. Therefore, when the actuator is compressed, the main body will inhibit the extension of the module, while the rings will limit radial expansion. The reinforced shell allows the endoscope to bend and straighten when driven from a standstill. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of the present invention;

[0013] Figure 2 This is a cross-sectional view of point A in this invention;

[0014] Figure 3 Figure showing the effect of different drive chamber cross-sectional areas on the performance of a novel pre-bent endoscope using finite element analysis;

[0015] Figure 4 Figure showing the effect of different numbers of rings on the performance of a novel pre-bent endoscope using finite element analysis.

[0016] Figure 5 Figure showing the effect of different trunk widths on the performance of a novel pre-bent endoscope using finite element analysis;

[0017] Figure 6A diagram of the experimental setup for characterizing the motion of an endoscope;

[0018] Explanation of reference numerals in the attached drawings: 1-outer shell, 2-main trunk, 3-ring, 4-reinforced chamber, 5-drive chamber, 6-free central cavity. Detailed Implementation

[0019] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0020] Please see Figure 1 A preferred embodiment of the present invention provides a novel asymmetric pneumatic endoscope device for achieving pre-bending, comprising: a housing 1 with a diameter of 12 mm and a bending angle of 120° when stationary; a main shaft 2 and rings 3 disposed on the housing 1, the rings 3 being connected to the main shaft 2, and sixteen rings 3 being disposed thereon; a reinforcing chamber 4 disposed on the inner side of the main shaft 2; a driving chamber 5 disposed between the reinforcing chamber 4 and the housing 1; and a free central cavity 6 disposed between the reinforcing chamber 4 and the driving chamber 5; the diameter of the free central cavity 6 being 4.5 mm; the cross-sectional area of ​​the reinforcing chamber 4 being no greater than the cross-sectional area of ​​the driving chamber 5; the cross-sectional area of ​​the driving chamber 5 being half the cross-sectional area of ​​the endoscope; the width of the main shaft 2 being 1.5 mm; and the housing 1 being non-expandable. The pre-bending flexible endoscope is based on a single-chamber shell reinforced flexible pneumatic actuator. The main body of the endoscope consists of a drive chamber 5, a reinforcing chamber 4, and a free central cavity 6 with a diameter of 4.5 mm. The endoscope is encased in a non-expandable shell 1 consisting of a main shaft 2 and rings 3. The shell 1 is reinforced similarly to the rings 3 used in bending pneumatic actuators, which are connected to the main shaft 2 running along the outer arc of the bending actuator. Therefore, the distance between these rings 3 is farther along the outer arc and closer along the inner arc. When the actuator is pressurized, the main shaft 2 will inhibit the expansion of the module, while the rings 3 will limit radial expansion. The reinforcement of the shell 1 allows the endoscope to bend until it becomes straight. The reinforcing chamber 4 is located next to the main shaft 2, and the variable reinforcement mechanism is a laminar flow disturbance, which is affected by the available space and the required force output. The drive chamber 5 is opposite the main shaft 2, and this radial structure is chosen to limit radial expansion by placing the drive chamber 5 along the inner arc. Parts of the endoscope are not completely covered by the reinforcement of the shell 1, and additional sheaths are used to limit excessive radial expansion.

[0021] Example 1:

[0022] This embodiment provides a single-chamber shell-based enhanced soft pneumatic actuator. (See reference...) Figure 1-2The endoscope's main body consists of a drive chamber 5, a reinforcing chamber 4, and a free central cavity 6 with a diameter of 4.5 mm. It is enclosed in a non-extendable outer shell 1, which consists of a main shaft 2 and a ring 3. The design of the outer shell 1 is similar to the ring used in a bending pneumatic actuator, and the ring 3 is connected to the main shaft 2, which extends along the outer arc of the bending actuator. The endoscope has a bending angle of 120° when at rest, and the pre-bending design has a diameter of 12 mm. The reinforcing chamber 4 is located next to the main shaft 2, while the drive chamber 5 is opposite to the main shaft 2. This radial structure is chosen to limit radial expansion by placing the drive chamber along the inner arc.

[0023] Example 2:

[0024] This embodiment provides a finite element model of an endoscope to evaluate design aspects of an endoscope module; the endoscope is modeled using COMSOL Multiphysics 5.5, incorporating solid mechanics (body), membrane (trunk), and truss (ring); the modeled endoscope consists only of a drive chamber with a reinforcing chamber and a free central lumen modeled as "filled" to represent the endoscope's state in clinical use; such as Figure 3-5 As shown, through finite element analysis, the effects of several design parameters, such as the cross-sectional area of ​​the drive chamber 5, the number of rings 3, and the width of the main trunk 2, on the performance of the novel pre-bent endoscope were determined. Figure 3 It was shown that the cross-sectional area is proportional to the bending moment, with the maximum cross-sectional area exhibiting the greatest bending stress sensitivity; however, the large drive chamber 5 limits the space available for implementing the reinforcement mechanism, so a cross-sectional area of ​​1 / 2 of the endoscope circumference was chosen; the expansion during drive decreases with increasing number of rings 3, and the maximum bending angle increases with increasing number of rings 3; Figure 4 The results show that all designs initially exhibit similar motion curves, with deviations only appearing after the model stiffness decreases due to the ballooning effect; while the design's bending performance increases, its maximum bending is affected; expansion weakens the actuator wall by reducing its thickness; due to manufacturing constraints, the design selects a maximum of 16 rings; the main trunk 2 extends along the outer arc of the endoscope, and because it is defined as a non-stretchable material, a larger main trunk 2 width increases the model's stiffness, thus suppressing bending performance; as... Figure 5 As shown, a trunk width of 1.5 mm is used because it contributes very little to the overall stiffness and has the greatest bending sensitivity to pressure.

[0025] Example 2:

[0026] To further illustrate the beneficial effects that the present invention can achieve, a series of experiments were conducted.

[0027] The manufacturing process of the endoscope is divided into three stages: elastomer molding, shell reinforcement, and outer sheath; the elastomer molding uses Ecoflex 00-30 with two cavities to manufacture the body of the endoscope. Laminar flow cardboard is stacked and inserted into the reinforcement chamber 4; the non-expandable shell 1 is manufactured using a thin, laser-cut sheet of plastic with a thickness of 0.3 mm.

[0028] Figure 6 An experimental setup for characterizing the motion of a fully fabricated endoscope was demonstrated, using an NDI Aurora position sensor to measure the endoscope's bending performance under pressure. The endoscope was placed on an Aurora desktop field generator, with the position sensor connected to the endoscope's tip along the outer arc and parallel to the main shaft 2; the flexible endoscope module was driven by gradually increasing and then decreasing the pressure from 0 to 0.6 bar; during this process, the input pressure and tip orientation were measured over four increasing and decreasing drive cycles; the results showed that the advantage of bending the endoscope is that the nonlinear start-up transient is reduced and moved out of the center of the operating range; by starting from the bending position, the angle of the endoscope approaching a straight configuration can be better controlled.

[0029] From the above description, it can be seen that the embodiments of the present invention achieve the following technical effects: By reducing and moving the transient out-of-operation range during activation, the flexibility of the endoscope is improved, thereby enhancing the controllability of small angles in near-straight configurations; the non-expandable housing 1 of the pre-bent soft endoscope, since the rings 3 are connected to the main body 2 running along the outer arc of the bending actuator, these rings 3 are further apart along the outer arc and closer together along the inner arc; therefore, when the actuator is compressed, the main body 2 will inhibit the extension of the module, while the rings 3 will limit radial expansion; the reinforced housing 1 allows the endoscope to... The curved endoscope straightens when driven from a stationary position; the nonlinear start-up transient of the curved endoscope has been reduced and moved out of the center of the working range; by starting from a curved position, the angle at which the endoscope approaches a straight configuration can be controlled more precisely; some parts of the endoscope are not completely covered by the housing reinforcement, and excessive radial expansion is limited by the use of additional sheaths; this strengthens the module by increasing stiffness and significantly reducing the probability of mechanical failure due to expansion and rupture under high pressure; the curved endoscope has only two pneumatic chambers, which can reduce the size of the endoscope for surgical applications.

[0030] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A novel asymmetric pneumatic endoscope device for achieving pre-bending, characterized in that, include: The outer shell (1) has a diameter of 12 mm and a bending angle of 120° when stationary. The outer shell (1) is provided with a main body (2) and a ring (3). The ring (3) is connected to the main body (2), and there are sixteen rings (3). A reinforcing chamber (4) is provided on the inner side of the main body (2). A driving chamber (5) is provided between the reinforcing chamber (4) and the outer shell (1). The driving chamber (5) is opposite to the main body (2). A free central cavity (6) is provided between the reinforcing chamber (4) and the driving chamber (5). The diameter of the free central cavity (6) is 4.5 mm; The cross-sectional area of ​​the reinforcing chamber (4) is not greater than the cross-sectional area of ​​the driving chamber (5); The cross-sectional area of ​​the drive chamber (5) is 1 / 2 of the cross-sectional area of ​​the endoscope; The width of the main stem (2) is 1.5 mm; The outer shell (1) is not expandable.

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