Multi-functional dissection knife

Abstract

The present invention provides a dissection knife adapted for connection with a flexible manipulator. In one embodiment, said dissection knife comprises a) a ball-head-type knife (20) comprising a hollow tube (22) and a spherical tip (23); b) a needle knife (21) comprising a free end and a fixed end; wherein said free end is inserted through said hollow tube (22); c) a channel (24), wherein said fixed end of the needle knife is connected and said spherical tip of the ball-head-type knife contacts when retracted; and d) a tendon-sheath mechanism (32) for retracting or extending said ball-head-type knife to expose or hide said needle knife (21) respectively.

Description

MULTI-FUNCTIONAL DISSECTION KNIFEFIELD OF THE INVENTION

[0001] This patent application generally relates to surgical devices in minimally invasive surgery (MIS), in particular, a multi-functional dissection knife to perform procedures of an Endoscopic Submucosal Dissection (ESD).BACKGROUND OF THE INVENTION

[0002] For patients suffering from early stage gastric and colorectal cancers, endoscopic surgeries are usually performed. These less incisive procedures remove pre-malignant and cancers in the Gastrointestinal (GI) tract. Some commonly known advanced endoscopic procedures are Endoscopic Mucosal Resection (EMR) and Endoscopic Submucosal Dissection (ESD). ESD associated with a larger and deeper lesion of dissection down to the submucosal layer, which increase the rate of complete removal of the GI tumors that grow from the mucosal layer, proceeds less chance of local recurrence compared to EMR, thereby are usually required.

[0003] ESD generally involves six steps: marginal marking around the lesion, submucosal injection to elevate the lesion from the muscle layer, circumferential incision surrounding mucosa of the lesion, subsequent dissection of the tissues of the submucosa beneath and removing the lesion. ESD is a demanding surgical process associated with a high risk of complications such as perforation and bleeding. Therefore, a combination of electrocauteries specialized for different tasks is usually used to prevent major complications.

[0004] Electrocautery used to perform incision can be characterized to needle-type knife and ball-head-type knife. A needle-type knife has a smaller contact area at the tip than that of a ball- head-type knife, providing greater current density, incision precision and ability, thereby increasing is favored in tasks such as marking and when significant submucosal fibrosis presents. A ball-head-type knife with a ball made of insulated material at the tip to prevent gastric wall perforation, is often used in dissection process instead. Adapted to the idea that both types of electrocauteries may be necessary for an ESD, this multi-functional dissection knife combine them in a single device.

[0005] Tendon-sheath (TS) mechanism is adapted to control the translation between two types of knives. Like other cable drive mechanisms, TS mechanism is able to transmit force through a narrow, torturous channel. The sheath minimizes the friction experienced by the tendon and acts as a force turning device that eliminates the unwanted coupling movements of the flexible manipulator while transmitting actuating for to the distal end device.SUMMARY OF THE INVENTION

[0006] The present invention provides a dissection knife adapted for connection with a flexible manipulator. In one embodiment, said dissection knife comprises a) a ball-head-type knife (20) comprising a hollow tube (22) and a spherical tip (23); b) a needle knife (21)comprising a free end and a fixed end; wherein said free end is inserted through said hollow tube (22); c) a channel (24), wherein said fixed end of the needle knife is connected and said spherical tip of the ball-head-type knife contacts when retracted; and d) a tendon-sheath mechanism (32) for retracting or extending said ball-head-type knife to expose or hide said needle knife (21) respectively.

[0007] The present invention provides a method for using said dissection knife of this invention. In one embodiment, said method comprises the steps of: a) providing said dissection knife to a site to be dissected; b) connecting said dissection knife with electricity; and c) conducting dissection by: i) contacting said site with said ball-head-type knife; or ii) retracting said ball-head-type knife to expose said needle knife and contacting said site with said needle knife.

[0008] The foregoing and other aspects and advantages of the invention will appear from the following description. In the description, reference is made to the accompanying drawings that form a part hereof, and in which there is shown by way of illustration a preferred embodiment of the invention. Such embodiment does not necessarily represent the full scope of the invention, however, and reference is therefore made to the claims and herein for interpreting the scope of the invention.BRIEF DESCRIPTION OF THE FIGURES

[0009] The embodiments of the present disclose will be described below with drawings, for purposes of illustration and not limitation. Same or liked parts share the same reference number across the figures.

[0010] FIG. 1 is a schematic diagram illustrating multi-functional dissection knife embedded in a flexible manipulator which combines and translates between a needle knife and ball-head-type knife.

[0011] FIG. 2 is a schematic diagram illustrating the cross-sectional area of the multifunctional dissection knife.DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention provides a dissection knife adapted for connection with a flexible manipulator. In one embodiment, said dissection knife comprises a) a ball-head-type knife (20) comprising a hollow tube (22) and a spherical tip (23); b) a needle knife (21) comprising a free end and a fixed end; wherein said free end is inserted through said hollow tube (22); c) a channel (24), wherein said fixed end of the needle knife is connected and said spherical tip of the ball-head-type knife contacts when retracted; and d) a tendon-sheath mechanism (32) for retracting or extending said ball-head-type knife to expose or hide said needle knife (21) respectively.

[0013] In one embodiment, said spherical tip is made of an insulated material.

[0014] In one embodiment, said dissection knife further comprising a non-conductive catheter 25 or / and a knife holder 26.

[0015] In one embodiment, said tendon-sheath mechanism (32) provides push-pull translational motion.

[0016] In one embodiment, said tendon-sheath mechanism (32) comprises tendon (32) and coil sheath (33).

[0017] In one embodiment, said flexible manipulator comprises a continuum structure (1) controlled by two pairs of pull-pull configured tendons (31).

[0018] In one embodiment, said needle knife (21) is made of a metal wire.

[0019] In one embodiment, said hollow tube (22) comprises a first section, a second section and a third section; wherein said first section (221) is for wrapping around said needle knife; said second section (222) is for a turning part of said needle knife to transit through; said third section (223) is for connecting said tendon-sheath mechanism (32).

[0020] The present invention provides a method for using said dissection knife of this invention. In one embodiment, said method comprises the steps of: a) providing said dissection knife to a site to be dissected; b) connecting said dissection knife with electricity; and c) conducting dissection by: i) contacting said site with said ball-head-type knife; or ii) retracting said ball-head-type knife to expose said needle knife and contacting said site with said needle knife.

[0021] In one embodiment, said site is a site for endoscopic submucosal dissection.

[0022] This invention provides a method for applying a flexible manipulator with a fusion of two distinct dissectors in an endoscopic submucosal dissection (ESD). In one embodiment, said method comprises: a) Performing dissection procedures with aid of a needle knife 21 and a ball-head-type knife 20 that are connected to electricity and, b) Alternating the use of the needle knife 21 and the ball-head-type knife 20 of the multi-functional dissection knife 2 by controlling the push-pull configured TS mechanism 32 when necessary, during the ESD.

[0023] The present invention discloses a multi-functional dissection knife specified for the procedures of Endoscopic Submucosal Dissection (ESD). Marking and dissecting can be performed with dexterity at once with this manipulator. The multi-functional dissection knife is embedded in a flexible manipulator which combines and translates between a needle knife and a ball-head knife by a push-pull tendon-sheath mechanism. In one embodiment, a multifunctional dissection knife 2 comprises a needle knife 21, a ball-head- type knife 20 with a hollow metal tube 22 and a sphere tip 23, a channel 24, a non-conductive catheter 25, a knife holder 26 and a push-pull configured tendon 32.

[0024] In one embodiment, the hollow tube 22 of the ball-head-type knife 20, wrapping around the needle knife 21, translate along to fully cover or uncover the needle knife 21.

[0025] In one embodiment, the translational range of the ball-head-type knife 20 is defined by two stoppers which are a section of the hollow tube 223 and the sphere tip 23. When theball-head-type knife 20 is fully extended, a section of the hollow tube 223 collides with the turning section of the needle knife 211 and, when the ball-head-type knife 20 is fully retracted, the sphere tip 23 collides with the channel 24.

[0026] In one embodiment, the push-full tendon 32 is connected to the hollow tube 223. The push-pull translational motion of the tendon 32, relative to the sheath 33 channeled through the continuum structure 1, drives the multi-functional dissection knife 2.EXAMPLE

[0027] The multi-functional dissection knife is embedded in a flexible manipulator which combines and translates between a needle knife and a ball-head knife by a push-pull tendonsheath mechanism.

[0028] FIG. 1 shows the complete assembly of the multi-functional dissection knife which embedded in a flexible manipulator. It comprises two types of knives 2, a continuum structure of flexible manipulator 1 and tendon-and-sheath (TS) mechanisms 3 for actuation. The multifunctional dissection knife 2 with one degree of freedom (DOF) may comprise two operation mode - needle knife 21 mode and ball-head-type knife 20 mode to interchange during an endoscopic submucosal dissection (ESD). The multi-functional dissection knife 2 is controlled by a push-pull configured tendon 32 with coil sheath 33 and the continuum structure 1 is manoeuvred with two pairs of pull-pull configured tendons 31. The assembly 100 is held together by the metal coated tendons 31 that pass through the continuum structure 1 and a part of the multi-functional dissection knife 2 with metal anchors 34.

[0029] FIG. 2 illustrates the cross-sectional areas of the multi-functional dissection knife in needle knife 21 mode and ball-head-type knife 20 mode. The multi-functional dissection knife comprises a needle knife 21 made of metal wire, a ball-head-type knife 20 with a hollow metal tube 22 and a sphere tip 23 made of insulated material, a channel 24 where the needle knife 21 is attached to, a non-conductive catheter 25, a knife holder 26 and a push-pull configured tendon 32. The hollow metal tube may comprise three sections: a hollow tube 221 that wraps around the needle knife for dissection, a segment arc section 222 where the tube is cut out for the turning part of the needle knife to transit through and a connector section 223 that combine the tube segment and the tendon. To define the translational range of the ball-head-type knife 20, the sphere tip 23 and the connector section 223 act as the upper and lower stoppers respectively. Specifically, when the tendon 32 is pulled that the sphere tip 23 collides with the channel 24, the ball-head-type knife 20 is fully retracted and the needle knife 21 is at its longest length; when the tendon 32 is pushed that the connector section 223 collides with the turning section 211 of the needle knife 21, the ball-head-type knife 20 is fully extended at its longest length and the needle knife 21 should be fully hidden inside the hollow tube 221.

Claims

What is claimed is:

1. A dissection knife adapted for connection with a flexible manipulator, comprising: a. A ball-head-type knife (20) comprising a hollow tube (22) and a spherical tip (23); b. A needle knife (21) comprising a free end and a fixed end; wherein said free end is inserted through said hollow tube (22); c. A channel (24), wherein said fixed end of the needle knife is connected and said spherical tip of the ball-head-type knife contacts when retracted; and d. A tendon-sheath mechanism (32) for retracting or extending said ball-head-type knife to expose or hide said needle knife (21) respectively.

2. The dissection knife of claim 1, wherein said spherical tip is made of an insulated material.

3. The dissection knife of claim 1 , further comprising a non-conductive catheter 25 or / and a knife holder 26.

4. The dissection knife of claim 1 , wherein said tendon-sheath mechanism (32) provides push-pull translational motion.

5. The dissection knife of claim 1, wherein said tendon-sheath mechanism (32) comprises tendon (32) and coil sheath (33).

6. The dissection knife of claim 1, wherein said flexible manipulator comprises a continuum structure (1) controlled by two pairs of pull-pull configured tendons (31).

7. The dissection knife of claim 1, wherein said needle knife (21) is made of a metal wire.

8. The dissection knife of claim 1, wherein hollow tube (22) comprises a first section, a second section and a third section; wherein said first section (221) is for wrapping around said needle knife; said second section (222) is for a turning part of said needle knife to transit through; said third section (223) is for connecting said tendon-sheath mechanism (32).

9. A method for using said dissection knife of claim 1, comprising the steps of: a. Providing said dissection knife to a site to be dissected; b. Connecting said dissection knife with electricity; andc. Conducting dissection by: i. Contacting said site with said ball-head-type knife; or ii. Retracting said ball-head-type knife to expose said needle knife and contacting said site with said needle knife.

10. The method of claim 9, wherein said site is a site for endoscopic submucosal dissection.

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