Systems for limiting movement of control mechanisms

Abstract

To provide locking mechanisms for medical devices, such as, devices for locking articulation movement control knobs of endoscopes.SOLUTION: An assembly may have an axle. Rotation of the axle may cause deflection of a portion of a medical device. A collet may have an opening. The axle may extend through the longitudinal opening. An actuator may be configured to interact with the collet. A first configuration of the collet may permit rotation of the axle relative to the collet and a second configuration of the collet may inhibit rotation of the axle relative to the collet.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention generally relates to systems for restricting the movement of a control mechanism. More particularly, the present invention relates to a locking mechanism for a medical device, such as an apparatus for locking an articulation control knob of an endoscope.

Background Art

[0002] The handle of a medical device, such as an endoscope, may include a control mechanism, such as a knob. Such a control mechanism can be used, for example, to cause the sheath of the medical device to articulate. During a procedure, the operator may desire to limit the articulation of the sheath. For example, the operator may desire to limit the articulation when the sheath is being inserted into the patient or while the procedure is being performed. Thus, there is a need for a locking mechanism.

Summary of the Invention

[0003] The assembly may have a shaft. Rotation of the shaft can cause deflection of a portion of the medical device. The collet may have an opening. The shaft may extend through the longitudinal opening. The actuator may be configured to interact with the collet. A first form of the collet may allow rotation of the shaft relative to the collet, and a second form of the collet may prevent rotation of the shaft relative to the collet.

[0004] Any of the assemblies described in this specification may have any of the following features. The actuator may comprise a protrusion. The collet may comprise a tab. The protrusion may interact with the tab to shift the collet from a first form to a second form. The protrusion may be a first protrusion. The actuator may further comprise a second protrusion and a third protrusion. The tab may be a first tab. The collet may further comprise a second tab and a third tab. The second protrusion and the third protrusion may interact with the second tab and the third tab respectively to shift the collet from a first form to a second form. A notch in the collet may define a portion of the tab having a reduced length compared to an adjacent portion of the tab. The tab may have a first portion and a second portion. The first portion may be less flexible than the second portion. In the first form, the protrusion may interact with the first portion. In the second form, the protrusion may interact with the second portion. The second portion may have a greater thickness than the first portion along a radial direction. When the collet is in the first form, the tab may be biased to a rest position. The radially inner surface of the tab may be radially aligned with an adjacent portion of the collet or may protrude radially outward from an adjacent portion of the collet. The collet may be shifted from a first form to a second form by rotation of the actuator. The actuator may comprise a lever. The actuator may comprise a washer-like portion. The lever may extend radially outward from the washer-like portion. The collet may comprise a sleeve and a flange extending circumferentially around at least a portion of the sleeve. The collet may be provided with a stop configured to prevent a part of the actuator from moving past the stop. The actuator may be located radially outside the collet. Rotation of the actuator may shift the collet from a first form to a second form. When the collet is in the second form, the flexible tab of the collet may apply a frictional force to the shaft.

[0005] In another example, the assembly can include a collet having a flexible tab and an actuator, the actuator having a protrusion extending radially inwardly from a surface of the actuator. The protrusion can interact with the tab to transition the collet from a first configuration to a second configuration. In the first configuration of the collet, the shaft can be rotatable to deflect a portion of the medical device. In the second configuration of the collet, the shaft can be rendered non-rotatable due to frictional forces applied to the shaft from the tab.

[0006] Any of the assemblies described herein may include any of the following features. The actuator may comprise a washer-like portion. The protrusion may extend from an inner surface of the washer-like portion. The tab may be radially aligned with an adjacent portion of the collet or biased to a rest position protruding radially outwardly from an adjacent portion of the collet.

[0007] In another example, the assembly may include a shaft. Rotation of the shaft can cause deflection of a sheath of the medical device. The collet may have a sleeve portion. The shaft may extend through a central opening of the sleeve portion. The sleeve portion may have a flexible tab. The actuator may have a washer-like portion radially outward of the sleeve portion. The actuator may comprise a protrusion extending radially inwardly from an inner surface of the washer-like portion. The protrusion may be adjacent to at least a portion of the tab.

[0008] Any of the assemblies described herein may have any of the following features. The actuator can rotate relative to the collet such that the protrusion applies a radially inward force to the tab.

[0009] It should be understood that both the foregoing summary and the following detailed description are exemplary and explanatory only and are not restrictive of the claimed invention. As used herein, the terms "comprises," "comprising," or other variations thereof are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but also other elements not expressly listed or inherent to such process, method, article, or apparatus. The term "exemplary" is used in the sense of "example" rather than "ideal." The term "about" or "substantially" can be understood to refer to a range of + / - 10%. As used herein, the term "proximal" means in the direction closer to the operator, and the term "distal" means in the direction farther from the operator. Although an endoscope is referenced herein, references to an endoscope or endoscopic examination should not be construed as limiting the possible applications of the disclosed locking mechanism and other aspects. For example, the disclosed aspects may be used with a duodenoscope, bronchoscope, gastroscope, ureteroscope, colonoscope, catheter, diagnostic or therapeutic tool or device, or other types of medical devices.

[0010] Incorporated herein by reference and constituting a part of this specification, the accompanying drawings illustrate examples of the present disclosure and are helpful in explaining the principles of the present disclosure together with the description.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6A

Figure 6B

Figure 7

DETAILED DESCRIPTION OF THE INVENTION

[0012] The handle of an endoscope or other medical device (e.g., the operating portion of an endoscope) may include components used by an operator when performing a procedure with the endoscope. As described above, during a procedure, a medical professional may desire to limit the articulation of the distal end of the endoscope with a complex locking mechanism or additional device. Known medical devices may include a locking mechanism for preventing the articulation of a sheath and maintaining the position or orientation of the distal end of the medical device. Such a locking mechanism may include a number of components, which can contribute to a high manufacturing cost of the medical device. Problems associated with the assembly of a multi-component locking mechanism can also result in the disposal of medical devices that are improperly assembled after manufacture and prior to distribution, contributing to waste.

[0013] Referring now to FIG. 1, the handle 210 of the endoscope 200 may include a steering component or assembly that can be used to deflect the distal end 222 of the sheath 220 of the endoscope 200. The steering component may include a knob, lever, or other mechanism used to control the steering assembly. For example, one or more steering knobs 230 or levers may be used to articulate the sheath 220 in the up / down and left / right directions. The endoscope handle may also include a mechanism for preventing or restricting unwanted articulation of the sheath (e.g., during insertion or between other portions of a medical procedure). For example, the handle may include one or more brake assemblies 10 (see FIG. 2) that prevent or otherwise restrict articulation of the sheath. The brake assembly 10 may include an actuator such as a lever 32. The brake assembly 10 may be coaxial with the knob 230, for example, on the shaft 41. The lever 32 may be manufactured from a molded plastic material, or other materials such as metal or a combination of materials. The brake assembly 10 may also include a collet that can interact with the lever. In a first form of locking, the shaft of the steering assembly may rotate relatively freely with respect to the collet. In a second form of locking, the collet may be tightened around the shaft so that the shaft cannot rotate relative to the collet, or so that an increased amount of force is required to rotate it, e.g., an amount of force that would not be exerted in the normal course by a user of the device. Alternatively, tightening of the collet around the shaft may increase the amount of force required to rotate the shaft while still allowing rotation around the shaft (increasing the resistance to articulation).

[0014] Figure 2 shows an exemplary brake assembly 10. The brake assembly 10 may include an actuator 12 and a collet 14. By forming an assembly of two components, the locking mechanism for the endoscope can be simplified, thereby reducing the cost and complexity of manufacturing and / or assembly. The actuator 12 may include a washer-like portion or washer 20 that may have an inner surface 22 and an outer surface 24. The outer surface 24 may have a smooth annular shape or any other suitable shape. The inner surface 22 may have one or more protrusions 30 that are located more radially inward than adjacent portions of the inner surface 22. As shown in FIGS. 2-5, the inner surface 22 may have three protrusions 30. Alternatively, the inner surface 22 may have any suitable number of protrusions 30. Using more protrusions 30 may make it possible to increase the braking surface. The number of protrusions may match the corresponding features of the collet 14 described below. The protrusion 30 may have a radially innermost surface having a curved concave shape. Alternatively, the protrusion 30 may be flat, pointed, convexly curved, or have other shapes and may be keyed to the collet 14 as described below.

[0015] The lever 32 may extend radially outward from the outer surface 24 of the washer 20. The lever 32 may be configured to be contacted by a user of the endoscope to rotate the actuator 12. As shown in FIG. 2, the lever 32 may be cantilevered such that the radially outermost portion 34 of the lever 32 can be displaced axially from the plane defined by the washer 20. The cantilevered shape of the lever 32 may facilitate rotation of the actuator 12 when a user applies a force to the lever 32. The lever 32 may alternatively be another type of actuating mechanism such as a knob, a rotating mechanism, a slider, a screw, or other mechanism.

[0016] The collet 14 can have a sleeve 40 and a flange 42. The sleeve 40 can have a cross-section with different shapes such as a circular cross-section or an elliptical cross-section. The shape of the sleeve 40 can be complementary to the shape of the shaft 41 of the steering assembly, and the sleeve 40 extends around the shaft 41. The collet 14 can be composed of a compressible material such as plastic. The use of a compressible material can be useful when the tolerances are low or to limit friction. Additionally or alternatively, the collet 14 can be composed of a flexible material such that the tabs 50 are elastically deformed as described in more detail below and have a shape memory function.

[0017] As shown in FIGS. 2-3, the flange 42 can extend only over a portion around the outer peripheral surface of the sleeve 40. For example, the flange 42 can extend over half or approximately half around the outer peripheral surface of the sleeve 40. The flange 42 can include a ridge 44 at the radially outer peripheral edge of the flange 42. The ridge 44 can help restrain one or more components (not shown) of the steering assembly. The ridge 44 can include one or more holes 46, and the holes 46 can be used to fix the collet 14 to the handle of the endoscope or a part of the steering assembly so that the collet 14 cannot rotate relative to the handle portion of the endoscope. The collet 14 can be fixed directly or indirectly to the handle.

[0018] The sleeve 40 can include a longitudinal opening 48 that extends from the axially inner surface of the collet 14 to the axially outer surface of the collet 14. In this specification, the axially inner direction of the collet 14 can be the direction approaching the flange 42. The axially outer direction of the collet 14 can be the direction away from the flange 42. Referring particularly to FIG. 3, the sleeve 40 can include one or more tabs 50.

[0019] The tab 50 can be radially inset with respect to the outer surface 52 of the collet 14. For example, as shown in FIGS. 1-4, the collet 14 can have three tabs 50. The tab 50 can be formed by a notch 54 or a cutout on the collet 14, particularly as shown in FIGS. 3-5. For example, the notch 54 can be L-shaped having an axial component and a circumferential component. The number of tabs 50 can be made equal to the number of protrusions 30 of the actuator 12. Some portions of the tab 50 (such as the side surface of the tab 50 bounded by the notch 54 and the outermost axial side surface) may not be directly connected to the remainder of the collet 14 and can define a free end. Instead, the tab 50 may be formed without the notch 54, but can be defined by multiple portions of the collet 14 having relatively thinner walls and relatively thicker walls. Other portions of the tab 50 (such as other side surfaces of the tab 50) can be directly fixed to the remainder of the collet 14 and can define a fixed end. As particularly shown with respect to FIG. 3, the tab 50 can have at least two free ends including an axially outer free end 60 and a radially free end 62. The axially outer free end 60 can be the outermost axial side surface of the collet 14. The radially free end 62 can be parallel to the longitudinal axis of the sleeve 40. The tab 50 can have a radially fixed end 64. The fourth, axially inner end 66 of the tab 50 can have a fixed portion 68 and a free portion 66. The tab 50 can have a notch 72. The notch 72 can be a groove or indentation on the outermost surface of the tab 50 / collet 14 in the axial direction. The notch 72 can be approximately midway between the radially free end 62 and the radially fixed end 64. The portion of the notch 72 closest to the fixed portion 64 can be circumferentially aligned with the confluence point of the fixed portion 68 and the free portion 66.

[0020] The material of the free end / side portion, as well as the notch 72 and the tab 50, can impart flexibility to the tab 50 to move radially inward and radially outward toward and away from the opening 48. The portion of the tab 50 adjacent to the notch 72 may have increased flexibility compared to other portions of the tab 50. For example, a radially inward force exerted on the portion of the tab 50 near the radially free end 62 can have a greater effect on the tab 50 due to the notch 72 than it would if the notch 72 were not present. The tab 50 can be more easily displaced the closer it is to the radially free end 62 and can have less flexibility the closer it is to the radially fixed end 64. In particular, the tab 50 can have less flexibility in the region of the tab 50 near the fixed portion 68.

[0021] The tab 50 can be configured to bias such that the radially free end 62 of the tab 50 projects radially outward from the inner surface 80 of the sleeve 40. The tab 50 is biased radially outward to the rest position shown in FIG. 4 but is compressible in the radially inward direction. For example, the inner surface of the tab 50 can project radially outward relative to an adjacent portion of the inner surface 80 of the sleeve 40. Alternatively, the tab 50 can be biased such that at the rest position, the inner surface of the tab 50 is aligned or substantially aligned with the inner surface 80, and the tab 50 can be compressible in the radially inward direction.

[0022] As shown in FIGS. 2, 4, and 5, the inner circumferential surface of the washer 20 can have a shape complementary to the outer surface 52 of the sleeve 40. The protrusion 30 of the actuator 12 can interact with the tab 50 of the collet 14, as will be described later.

[0023] FIG. 4 shows the brake assembly 10 in the first unlocking configuration. In the first configuration, the protrusion 30 may be adjacent to and radially outside of a first portion 90 of the tab 50 near the radially fixed end 64. FIG. 6A shows a detailed enlarged perspective view of a portion of the brake assembly 10 in the first unlocking configuration. Thus, the protrusion 30 cannot interact with a second portion 92 of the tab 50 near the radially free end 62, and for example, due to the curvature of the tab 50, i.e., its inherent bias, the second portion 92 can project radially outward to the rest position. Instead, the second portion 92 may be aligned with the inner surface 80 of the sleeve 40 in the first configuration. Since the first portion 90 is close to the radially fixed end 64, the protrusion 30 cannot exert on the first portion 90 a force sufficient to push the first portion 90 into frictional interference with the shaft 41. For example, FIG. 6A shows a gap between the second portion 92 and the shaft 41. The fixed portion 68 of the axially inner end 66 may prevent the radially inward displacement of the first portion 90 by the protrusion 30 in the first configuration. In the first configuration, since the protrusion 30 does not exert a radially inward force on the shaft 41 via the tab 50, the shaft 41 may be rotatable relatively freely with respect to the collet 14.

[0024] Figures 5 and 6B show the brake assembly 10 in a second lock configuration. In the second configuration, the protrusion 30 can interact with a second portion 92. The second portion 92 can be thicker than other portions of the tab 50 along the radial direction of the collet 14 so as to facilitate interaction with the protrusion 30 in the second configuration. Since the second portion 92 has three free sides, namely, the free portion 66 of the axially outer free end 60, the radially free end 62, and the axially inner end 66 of the tab 50, and due to the material of the collet 14, the protrusion 30 can exert a force to displace the second portion 92 radially inward. For example, the protrusion 30 can have an interference of 0.0025 to 0.38 millimeters (0.0001 to 0.015 inches), including an interference of 0.025 to 0.18 millimeters (0.001 to 0.007 inches) with the tab 50 (for example, when the components of the brake assembly 10 are formed of polycarbonate). In the rest position, the radially free end 62 can extend past the radially inner end of the protrusion 30 radially outward. For example, the radially free end can protrude 0.025 to 1.3 millimeters (0.001 inch to 0.050 inches), including 0.051 to 0.51 millimeters (0.002 inches to 0.020 inches). The protrusion of the radially free end 62 can help hold the protrusion 30 (and / or the entire actuator 12) in a desired position when the brake assembly 10 is in the first configuration so that the protrusion 30 (and / or the entire actuator 12) does not move or rattle. The above numerical values are merely exemplary and can vary depending on the material used to form the components of the brake assembly 10.

[0025] Thus, in the second configuration, the protrusion 30 exerts a radially inward force on the tab 50. Due to the flexibility of the tab 50, the second portion 92 can be bent or displaced such that the second portion 92 is located radially inward of the inner surface 80 of the sleeve 40. The position of the first portion 90 can be the same or substantially the same in the first and second configurations. Alternatively, the first portion 90 may also be displaced relative to the first configuration in the second configuration, for example, radially inward. In the second configuration, the second portion 92 of each tab 50 can be compressed against the shaft 41. Interference between the actuator 12 (e.g., the protrusion 30 of the actuator 12), the tab 50, and the shaft 41 can cause friction. The frictional force between the tab 50 and the shaft 41 can prevent the shaft 41 from rotating relative to the collet 14. The friction generated can also hold the actuator 12 in the second configuration of the brake assembly 10. The tab 50 can be formed from a material that increases the frictional force. For example, the tab 50 may have a textured surface to increase the surface area and / or may be provided with a coating to increase the frictional force. Additionally or alternatively, the surface of the shaft 41 may be textured or provided with a coating to increase the friction.

[0026] The actuator 12 can be rotatably movable between the first and second configurations by the lever 32. For example, when the brake assembly 10 is in the first configuration, the actuator 12 can be moved counterclockwise to transition the brake assembly 10 to the second configuration. When the brake assembly 10 is in the second configuration, the actuator 12 can be moved clockwise to transition the brake assembly 10 to the first configuration. The tab 50 can be elastically flexible. When the brake assembly 10 is transitioned from the second configuration to the first configuration, the tab 50 can transition to a rest configuration (protruding radially outward from or aligning with the inner surface 80), and as a result, the collet 14 no longer prevents rotation of the shaft 41.

[0027] The materials of the collet 14 and the actuator 12 can be selected to minimize the force that should be exerted on the lever 32 by the operator when shifting the collet 14 from the first form to the second form. The flexibility of the tab 50, the compressibility of the material of the collet 14, the elasticity of the actuator 12 / lever 32, the amount of interference between the collet 14 and the actuator 12, and / or the radially protruding distance of the tab 50 all affect the force required to operate the lever 32. For example, both the collet 14 and the actuator 12 can be composed of high-strength plastic and / or polycarbonate materials. The collet 14 and / or the actuator 12 can be formed by molding, additive manufacturing or other manufacturing methods.

[0028] The sleeve 40 can include a first step 100 on one radial side of the tab 50 and a second step 102 on another radial side of the tab 50. For example, the first step 100 can be adjacent to the radially fixed end 64, and the second step 102 can be adjacent to the radially free end 62 and / or the notch 54. The second step 102 can be adjacent to the notch 54 on the side opposite to the radially free end 62 of the notch 54. The first step 100 and the second step 102 can act to limit the movement of the actuator 12 beyond the desired range of movement. When the brake assembly 10 transitions from the first form to the second form, the second step 102 can act as a stop to prevent the protrusion 30 from moving past the second step 102, such that the protrusion 30 engages the second portion 92. When the brake assembly transitions from the second form to the first form, the first step 100 can act as a stop to prevent the protrusion 30 from moving past the first step 100, such that the protrusion 30 is adjacent to the first portion 90.

[0029] The collet 14 may have interference features, such as surface features that provide resistance to the user-rotatable knob 230 when the brake assembly 10 is in the first configuration. The interference features may provide increased interference when the brake assembly 10 is in the second configuration. The interference features may affect how quickly the knob 230 can be rotated and thus how quickly the distal end 222 returns to the straight configuration. The interference features may include raised portions, protrusions, projecting portions, or other suitable features on the collet 14. Alternatively, such interference features may be disposed on a part of the actuator 12.

[0030] It will be understood that the above elements are merely exemplary. For example, as described above, various numbers of protrusions 30 may be used. In addition to or instead of utilizing a frictional relationship to impede movement between the collet 14 and the actuator 12, one or more mechanical features may be used. For example, the collet 14 and the actuator 12 may have mating features that align the collet 14 and the actuator 12 at selected positions. Such features may enable a user to engage the brake assembly 10 at a selected position or in a selected increment.

[0031] FIG. 7 shows another collet 100 that can be used with actuator 12. Collet 100 may have any of the features of collet 14 described above. Collet 100 may have one or more tabs 150 that extend axially. Notch 172 may define the end of tab 150. Notch 172 may have any of the features of notch 72. Notch 72 may extend only partially through tab 50 axially, while notch 172 may extend along the entire length of tab 150 from the proximally axially portion to the distally axially portion of tab 150. Collet 100 and / or collet 14 may use a combination of tab 50 and / or tab 150. Tab 150 may have three free ends and one fixed end. For example, tab 150 may have a first free radially fixed end 152, a second free radial end 154, and a free axial end 156. Free axial end 156 may be the axially most distal end of collet 100. Tab 50 may have a radially fixed end 160. Except for the orientation of tab 150, collet 100 may function in the same manner as collet 14 as described above with respect to FIGS. 1-6.

[0032] While the principles of the present disclosure have been described in connection with exemplary examples for specific applications, it should be understood that the present disclosure is not limited thereto. Those skilled in the art who can utilize the teachings provided herein will recognize that all additional changes, applications, aspects, and equivalent substitutions are within the scope of the examples described herein. Accordingly, the invention should not be regarded as limited by the foregoing description.

Claims

1. a shaft, rotation of which causes deflection of a portion of the medical device; and a collet having an opening, the axis extending through the longitudinal opening; an actuator configured to interact with the collet; An assembly, wherein a first configuration of the collet permits rotation of the shaft relative to the collet and a second configuration of the collet prevents rotation of the shaft relative to the collet.

2. The assembly of claim 1 , wherein the actuator comprises a protrusion and the collet comprises a tab, the protrusion interacting with the tab to transition the collet from a first configuration to a second configuration.

3. 3. The assembly of claim 2, wherein the protrusion is a first protrusion, the actuator further comprises a second protrusion and a third protrusion, the tab is a first tab, and the collet further comprises a second tab and a third tab, the second protrusion and the third protrusion interacting with the second tab and the third tab, respectively, to transition the collet from the first configuration to the second configuration.

4. 4. The assembly of claim 2 or 3, wherein a notch in the collet defines a portion of the tab having a reduced length compared to adjacent portions of the tab.

5. An assembly according to any one of claims 2 to 4, wherein the tab has a first portion and a second portion, the first portion being less flexible than the second portion.

6. The assembly of claim 5 , wherein in a first configuration, the protrusion interacts with a first portion and in a second configuration, the protrusion interacts with a second portion.

7. 7. An assembly according to claim 5 or 6, wherein the second portion has a greater thickness along a radial direction than the first portion.

8. An assembly as claimed in any one of claims 2 to 7, wherein when the collet is in a first configuration, the tabs are biased to a rest position such that a radially inner surface of the tab is radially aligned with or projects radially outwardly from an adjacent portion of the collet.

9. An assembly according to any preceding claim, wherein the collet is transitioned from a first configuration to a second configuration by rotation of the actuator.

10. An assembly according to any preceding claim, wherein the actuator comprises a lever.

11. The assembly of claim 10 , wherein the actuator comprises a washer-like portion, the lever extending radially outward from the washer-like portion.

12. An assembly according to any preceding claim, wherein the collet comprises a sleeve and a flange extending circumferentially around at least a portion of the sleeve.

13. An assembly according to any preceding claim, wherein the collet comprises a stop configured to prevent movement of a portion of the actuator past the stop.

14. An assembly according to any preceding claim, wherein the actuator is located radially outward of the collet, and rotation of the actuator transitions the collet from a first configuration to a second configuration.

15. The assembly of claim 14 , wherein a flexible tab of the collet exerts a frictional force against the shaft when the collet is in the second configuration.

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