WO2007116399A2

WO2007116399A2 - Grasping tool

Info

Publication number: WO2007116399A2
Application number: PCT/IL2007/000443
Authority: WO
Inventors: Zvi Zlotnik; Andrey Bogomolov
Original assignee: Bynet Electronics
Priority date: 2006-04-10
Filing date: 2007-04-10
Publication date: 2007-10-18
Also published as: WO2007116399A3

Abstract

A grasping tool device for delicately grasping tissue comprising: a plurality of electro-osmotic pumps, each electro-osmotic pump comprises a first and a second chambers separated by a first membrane so that when placed in contact with the tissue and when subjected to electric field force liquid in the first chamber to move to the second chamber, inducing sub-pressure in the first chamber and causing at least one second membrane to retract, thus effectively grasping the tissue. The electro-osmotic pumps are mounted on a support and connected to a control unit.

Description

GRASPING TOOL

FIELD OF THE INVENTION

[0001] The present invention relates to a grasping tool. More particularly it relates to a grasping tool incorporating one or more electro-kinetic pumps or other electrical devices which causes flow of a fluid from a first chamber to a second chamber, imparting sub-atmospheric pressure in the first chamber and facilitating gripping of an object. The present invention, although applicable in many areas has a special appeal in the medical field.

BACKGROUND OF THE INVENTION

[0002] In surgical operations, and especially in minimally invasive medical procedures it is many times desired to move aside, lift, lower, or fix in position an organ or limb (hereinafter generally referred to as "organ"). At the same time it is important to control and monitor the level of fixation of the organ, and insure that the pressure applied on the organ does not cause any harm, as in many cases internal organs are covered with very delicate and sensitive membranes. When the medical procedure is ended the organ must sometimes be placed in its original position. The vulnerability of internal organs lends itself to injuries and complications, resulting in prolonged hospitalizations, repeated medical procedures, injuries and even deaths, all of which could have been avoided had there been a more delicate grasper than conventional ones.

[0003] Various clamps, graspers and fixators are known in the art, and are widely used in operating rooms. These are various kinds of adaptations of mechanical pliers, tongs, tweezers and the like. These tools were originally designed to hold or fix objects with rough surfaces, and their adaptation to the medical world seems inadequate in many cases where delicate tissue is at stake. It is very difficult, if not impossible, to hold, fix, distract or otherwise engage tissue using these tools without harming that tissue. [0004] It is a main object of the present invention to provide a grasping tool that can delicately hold sensitive or delicate objects, and in particularly tissue and organs, and manipulate them without causing damage.

[0005] Another object of the present invention is to provide such grasping tool that can be incorporated with a robotic arm to participate in medical procedures.

[0006] Other objects and advantages of the present invention will become apparent after reading the resent specification and consulting the accompanying drawings.

SUMMARY OF THE INVENTION

[0007] There is thus provided, in accordance with some preferred embodiments of the present invention, a grasping tool device for delicately grasping tissue, the device comprising:

[0008] at least one of a plurality of electro-osmotic pumps, each electro-osmotic pump comprises a first and a second chambers separated by a first membrane so that when placed in contact with the tissue and when subjected to electric field force liquid in the first chamber to move to the second chamber, inducing sub-pressure in the first chamber and causing at least one second membrane to retract, thus effectively grasping the tissue, said at least one of a plurality of electro-osmotic pumps being mounted on a support and connected to a control unit.

[0009] Furthermore, in accordance with some preferred embodiments of the present invention, said at least one of a plurality of electro-osmotic pumps comprises at least one of a plurality of electro-kinetic pumps.

[0010] Furthermore, in accordance with some preferred embodiments of the present invention, the support comprises at least one arm.

[0011] Furthermore, in accordance with some preferred embodiments of the present invention, the arm comprises a robotic arm.

[0012] Furthermore, in accordance with some preferred embodiments of the present invention, the arm is made from elastic material, adapted to be influenced by actuation of said at least one of a plurality of electro-osmotic pumps, so that is bends upon activation of said at least one of a plurality of electro-osmotic pumps in a predetermined direction.

[0013] Furthermore, in accordance with some preferred embodiments of the present invention, at least some of the pumps comprise more than one second membrane.

[0014] Furthermore, in accordance with some preferred embodiments of the present invention, the device is further provided with a monitor.

[0015] Furthermore, in accordance with some preferred embodiments of the present invention, the device is incorporated in a catheter.

[0016] Furthermore, in accordance with some preferred embodiments of the present invention, said at least one arm comprises a plurality of arms, each arm having a first end and a second end, the arm made from elastic material, adapted to be influenced by actuation of said at least one of a plurality of electro-osmotic pumps, so that is bends upon activation of said at least one of a plurality of electro-osmotic pumps in a predetermined direction, each arm coupled at the first end to the catheter the second end remaining free.

[0017] Furthermore, in accordance with some preferred embodiments of the present invention, there is provided a method for delicately grasping tissue comprising:

[0018] providing at least one of a plurality of electro-osmotic pumps, each electro- osmotic pump comprising a first and a second chambers separated by a first membrane;

[0019] placing the device in contact with the tissue and subjecting it to electric field which forces liquid in the first chamber to move to the second chamber, inducing sub- pressure in the first chamber and causing at least one second membrane to retract,

[0020] thereby effectively grasping the tissue, said at least one of a plurality of electro- osmotic pumps being mounted on a support and connected to a control unit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to better understand the present invention, and appreciate its practical applications, the following Figures are provided and referenced hereafter. It should be noted that the Figures are given as examples only and in no way limit the scope of the invention. Like components are denoted by like reference numerals.

[0022] Fig. 1 illustrates a grasping tool in accordance with some preferred embodiments of the present invention.

[0023] Fig. 2a illustrates a suction cell of a grasping tool in accordance with a preferred embodiment of the present invention, before applying a grasping force on a tissue.

[0024] Fig. 2b illustrates a suction cell of a grasping tool in accordance with a preferred embodiment of the present invention, applying a grasping force on a tissue.

[0025] Fig. 2c illustrates a suction cell of a grasping tool in accordance with a preferred embodiment of the present invention, after the grasping force is ceased.

[0026] Fig. 3 a illustrates a double suction cell of a grasping tool in accordance with a preferred embodiment of the present invention, before applying a grasping force on a tissue.

[0027] Fig. 3b illustrates a double suction cell of a grasping tool in accordance with a preferred embodiment of the present invention, applying a grasping force on a tissue.

[0028] Figure 4a illustrates a grasping tool, according to another preferred embodiment of the present invention, incorporated in a catheter, in a cramped state.

[0029] Fig. 4b illustrates the grasping tool shown in Fig. 4a, in a deployed state.

[0030] Fig. 5a illustrates an arm of a grasping tool, according to a preferred embodiment of the present invention, in a slack state.

[0031] Fig. 5b illustrates an arm of the grasping tool shown in Fig. 5a, in a twisted state.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0032] A main aspect of the present invention is the provision of a grasping tool particularly useful in medical procedures and especially in minimally invasive procedures.

[0033] Another aspect of the present invention is the provision of a grasping tool that employs vacuum forces for holding an organ, instead of applying direct mechanical contact with the organ, thus avoiding or greatly reducing the risk of direct hit and subsequent mechanical damage.

[0034] Another aspect of the present invention is the provision of a grasping tool that may readily be used in minimally invasive procedures.

[0035] Yet another aspect of the present invention is the provision of a grasping tool that may, in some preferred embodiments, be incorporated with a robotic arm, or with other automated device.

[0036] The grasping tool of the present invention employs one or more electro-kinetic pumps. Electro-kinetic pumps are devices that comprise fluid confined to a cavity ^• having an opening that is covered with a membrane. When subjected to electric field the membrane is pulled inwardly, thus creating a suction force at the opening. In electroosmotic flow mobile ions in the charge double layer are driven by the applied electrical field, the moving ions will drag the bulk fluid through viscous forces, resulting in electroosmotic flow.

[0037] An electro-osmotic pump comprises a first and a second chambers separated by a first membrane so that when placed in contact with the tissue and when subjected to electric field force liquid in the first chamber to move to the second chamber, inducing sub-pressure in the first chamber and causing a second membrane to retract, thus effectively grasping the tissue.

[0038] The pumps are operated electrically using wires or wirelessly.

[0039] The electro-osmotic pumps can be operated continuously or intermittently. When more than one pump is used, in some preferred embodiments of the present invention, pumps may be operated separately in a predetermined order, in order to reduce local damage to the tissue. For example, when an arm with several pumps is used to grasp tissue, the pumps can be actuated in a sequence, one or more actuated for a certain period of time and replaced by one or more other pumps for another period of time, so that the tissue remains grasped, preventing local damage to the tissue. [0040] A control unit can monitor the sub-pressure values each pump exerts on the tissue at a given time and ensure that a predetermined threshold is not passed. [0041] A grasping tool device, according to the present invention can be used for a variety of tasks, some of which include: fixation, distraction (moving tissue to another desired position). The grasping tool of the present invention can be incorporated with a robot.

[0042] Reference is now made to the accompanying figures.

[0043] Fig. 1 illustrates a grasping tool in accordance with some preferred embodiments of the present invention. The grasping tool 10 generally comprises one or more suction caps 14 comprising electro-kinetic pumps. The suction caps 14 are mounted on an arm 12 and are electrically connected 26 to control unit 24. The control unit 24 is responsible for actuating and operating the suction caps 14, by applying or cutting off electric fields at the suction caps as appropriate. When the suction cap 14 is coupled to an organ and an electric field is applied on the liquid 16 inside the suction cap .14 it causes the membrane 18 to retract, generating a suction force at opening 20 that causes the suction cap to hold the organ. The arm 12 may be moved or held in position causing the organ to be moved or fixed in position. The arm may be coupled to a mechanical maneuvering actuator 22, and it may also be equipped with a monitor for displaying relevant information. The device is powered by a power unit 23 (for example, batteries or main electric supply).

[0044] Fig. 2a illustrates a suction cell of a grasping tool in accordance with a preferred embodiment of the present invention, before applying a grasping force on a tissue 30.

[0045] Fig. 2b illustrates a suction cell of a grasping tool in accordance with a preferred embodiment of the present invention, applying a grasping force on a tissue 30. As an electric field is applied on the suction cap the membrane 18 concaves exerting suction force on the organ 30, effectively holding it.

[0046] Fig. 2c illustrates a suction cell of a grasping tool in accordance with a preferred embodiment of the present invention, after the grasping force is ceased. The membrane regains its original position and the suction force stops releasing the organ from the grip of the grasping tool.

[0047] In some preferred embodiments of the present invention the suction caps may be each controlled separately. The suction force applied by the suction caps is substantially linear with respect to the electric field applied on the electro-kinetic pump. This facilitates fine-tuning of the grasping force.

[0048] The grasping tool of the present invention may be incorporated with a robotic arm, so as to allow automated operation or remote control.

[0049] Fig. 3a illustrates a double suction cell of a grasping tool in accordance with a preferred embodiment of the present invention, before applying a grasping force on a tissue. Partition 19 divides the cell into two suction cups covered with membranes 18.

[0050] Fig. 3b illustrates a double suction cell of a grasping tool in accordance with a preferred embodiment of the present invention, applying a grasping force on a tissue.

[0051] Figure 4a illustrates a grasping tool 40, according to another preferred embodiment of the present invention, incorporated in a catheter, in a cramped state. Catheter 42 is provided with a number of arms 44 coupled to the catheter at one of their ends - the end which is further from the catheter front tip 48. Each arm comprises several suction caps 46. A remote control transmitter 50 communicates with the device through receiver 43 incorporated in the catheter, so that the operator can remotely operate the device.

[0052] Fig. 4b illustrates the grasping tool shown in Fig. 4a, in a deployed state. Deployment of the arms 44 is achieved when the suction caps are activated (see Fig. 5a and Fig. 5b and explanation hereinafter).

[0053] Fig. 5a illustrates an arm 44 of a grasping tool (for example, the one shown in Fig. 4a), according to a preferred embodiment of the present invention, in a slack state. [0054] Fig. 5b illustrates an arm of the grasping tool shown in Fig. 5a, in a twisted state. The arm is made from elastic material, and when electrically activated, and as a result of the changes in pressures within the chambers of the electro-kinetic pumps the arm bends or curls in a predetermined direction. This facilitates deployment of the arms encircling the catheter tip 48.

[0055] It should be clear that the description of the embodiments and attached Figures set forth in this specification serves only for a better understanding of the invention, without limiting its scope. [0056] It should also be clear that a person skilled in the art, after reading the present specification could make adjustments or amendments to the attached Figures and above described embodiments that would still be covered by the present invention.

Claims

1. A grasping tool device for delicately grasping tissue, the device comprising: at least one of a plurality of electro-osmotic pumps, each electro-osmotic pump comprises a first and a second chambers separated by a first membrane so that when placed in contact with the tissue and when subjected to electric field force liquid in the first chamber to move to the second chamber, inducing sub-pressure in the first chamber and causing at least one second membrane to retract, thus effectively grasping the tissue, said at least one of a plurality of electro-osmotic pumps being mounted on a support and connected to a control unit.

2. The device as claimed in claim 1, wherein said at least one of a plurality of electro-osmotic pumps comprises at least one of a plurality of electro-kinetic pumps.

3. The device as claimed in claim 1, wherein the support comprises at least one arm.

4. The device as claimed in claim 3, wherein the arm comprises a robotic arm.

5. The device as claimed in claim 3, wherein the arm is made from elastic material, adapted to be influenced by actuation of said at least one of a plurality of electro- osmotic pumps, so that is bends upon activation of said at least one of a plurality of electro-osmotic pumps in a predetermined direction.

6. The device as claimed in claim 1, wherein at least some of the pumps comprise more than one second membrane.

7. The device as claimed in claim 1, further provided with a monitor.

8. The device as claimed in claim 1, incorporated in a catheter.

9. The device as claimed in claim 8, wherein said at least one arm comprises a plurality of arms, each arm having a first end and a second end, the arm made from elastic material, adapted to be influenced by actuation of said at least one of a plurality of electro-osmotic pumps, so that is bends upon activation of said at least one of a plurality of electro-osmotic pumps in a predetermined direction, each arm coupled at the first end to the catheter the second end remaining free.

10. A method for delicately grasping tissue comprising: providing at least one of a plurality of electro-osmotic pumps, each electro-osmotic pump comprising a first and a second chambers separated by a first membrane; placing the device in contact with the tissue and subjecting it to electric field which forces liquid in the first chamber to move to the second chamber, inducing sub-pressure in the first chamber and causing at least one second membrane to retract, thereby effectively grasping the tissue, said at least one of a plurality of electro-osmotic pumps being mounted on a support and connected to a control unit.

11. The method as claimed in claim 10, wherein said at least one of a plurality of electro-osmotic pumps comprises at least one of a plurality of electro-kinetic pumps.

12. The method as claimed in claim 10, wherein the support comprises at least one arm.

13. The method as claimed in claim 12, wherein the arm comprises a robotic arm.

14. The method as claimed in claim 12, wherein the arm is made from elastic material, adapted to be influenced by actuation of said at least one of a plurality of electro-osmotic pumps, so that is bends upon activation of said at least one of a plurality of electro-osmotic pumps in a predetermined direction.

15. The method as claimed in claim 10, wherein at least some of the pumps comprise more than one second membrane.

16. The method as claimed in claim 10, further comprising incorporating the device in a catheter.

17. The method as claimed in claim 16, wherein said at least one arm comprises a plurality of arms, each arm having a first end and a second end, the arm made from elastic material, adapted to be influenced by actuation of said at least one of a plurality of electro-osmotic pumps, so that is bends upon activation of said at least one of a plurality of electro-osmotic pumps in a predetermined direction, each arm coupled at the first end to the catheter the second end remaining free.