Apparatus and method for automatic catheter threader

Abstract

A system for the automated threading of catheters with cables, wires or fluid conductors during their manufacture is presented. The system provides for a vacuum catheter sheath clamping and enlarging mechanism that facilitates the treading of catheters within very tight confines. The system also provides for rotating needle and or conductor pushing and pulling mechanisms to allow the rapid threading of the catheters with carefully controlled parameters. These pushing and pulling mechanisms are monitored through force, torque, and position sensors so that materials are not damaged during manufacture.

Description

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT

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RELATED APPLICATIONS

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BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the manufacture and assembly of catheters for use or as a part of medical devices. More specifically, the present invention relates to an apparatus and method by which some of the manufacturing procedures of catheters may be considerably sped up and made safer by automated operations.

2. Discussion of the Background

Catheters are flexible medical devices that are inserted into a human or animal body to perform different procedures, such as exploration, sampling, surgery, expansion, and connection of devices. Catheters must perform under conflicting considerations: they must be flexible enough to pass through veins and arteries, but stiff enough not to collapse under pressure. Catheters may also contain wires and fluid conductors that must be isolated from the subject body.

At present, very skilled persons in a very time consuming and costly process perform most catheter manufacture manually. Some of the operations performed on tubing and other flexible materials may be dangerous or hazardous to the persons, such as when a worker must present tubing to a clamping device that may nab the person's fingers. The present invention presents an apparatus and method by which some of the manufacturing procedures may be considerably sped up and made safer by automated operations.

Catheters, tubing, cables, wires, and filamentary materials are notoriously difficult to handle, and have been the focus of much research. See for example Robot Manipulation of Deformable Objects, Dominik Henrich and Heinz Wörn editors, ISBN 1-85233-250-6 Springer Verlag London Limited 2000; and Mechanics of Robotic Manipulation by Matthew T. Mason, ISBN 0-262-13396-2, The MIT Press, Cambridge, Mass. 2001. However, no systematic solution to the problem of threading catheters has been found in the literature. Some methods related to the problem at hand are found in the following patents, which are incorporated herein by reference:

• • A. U.S. Pat. No. 6,544,367, to Katzutoshi Fujimoto, and Lloyd Miller ('367);
  • B. U.S. Pat. No. 6,357,994, to Douglas L. St. Onge ('994);
  • C. U.S. Pat. No. 6,021,244 to Ronald O. Simpson ('244); and
  • D. U.S. Pat. No. 5,811,951 to Kar-Keung and David Young ('951).

U.S. Patent '244 teaches the process and apparatus to assemble fiber optic strands into sign components. This patent attacks the problem of handling fiber by maintaining the bulk of the fiber in roll and then inserting the individual strands into a holder. A specialized needle is used to insert the fiber strands into the holder.

U.S. Patent '367 describes an end-effector for applying tape materials to bundles of fibers. However, the patent does not teach how the fibers themselves are handled.

U.S. Patent '994 presents a multi purpose end-effector for a robotic arm that moves a workpiece through a multi station manufacturing operation. In this case the operation involves several steps in the manufacture of gears.

The following patents are pertinent to the topic of speeding up and making safer the manufacturing procedures of catheters by automated operations and are incorporated herein by reference:

A. U.S. Pat. No. 5,022,952 ('952).

B. U.S. Pat. No. 6,736,156 ('156)

B. U.S. Pat. No. 5,354,518 ('518)

C. U.S. Pat. No. 6,591,472 ('472).

Patent '952 to Milo M. Vaniglia presents a FIBER PLACEMENT-MACHINE for the placement of one or several rows of filamentary fiber material for the purpose of reinforcing composite materials.

Patent '156 to Scott A. Beals and Ronald D. Hammer for a METHOD FOR INSTALLING CABLE IN PRESSURIZED PIPELINES teaches the use of rollers and conveyors to introduce long sections of communications fiber optic cable into pressurized pipelines.

Patent '518 to Yosuke Okada and Yumiko Suzuki, for a METHOD FOR MANUFACURING A FIBERCOPIC CATHETER teaches the method of threading a catheter by heating expanding the catheter sheath by injecting internally a fluid under pressure.

Patent '472 to Michael S. Noone et al. for MULTIPLE SEGMENT CATHETER AND METHOD OF FABRICATION teaches how a cathether may be formed from extruding several layers of material over a mandrel.

While the aforementioned devices or methods in the prior art fulfill their respective, particular objectives and requirements, none of them, however, teach neither the apparatus nor methods by which to automate the threading of a catheter sheath with the wires, optical fibers or fluid conductors required for the operation of the catheter while in production. Thus, it can be appreciated that there is a continuing need for a new and improved method and apparatus for the threading of catheter sheaths that overcomes the deficiencies already noted in the prior art. In this regard, the present invention substantially fulfills this need.

In addition, none of the existing art, taken either simply or in combination teaches the use of the very principle of the automated threading of catheter sheaths. In this respect, the device according to the present invention substantially departs from the conventional concepts and designs of the prior art to fulfill the aforementioned needs.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a device to grasp a section of tubing material with rotating and force controlled means that will form the sheath or envelope of a catheter.

It is a further object of the present invention to provide the means to grasp a needle like object with rotating and force controlled means to accomplish the movement of said needle by pushing or pulling mechanisms.

It is another object of the present invention to measure the amount of rotation or movement of the grasping means for the tubing sheath and for the needle.

Another object of this invention is to provide the means to measure the rotational torque impressed to the shafts of both the grasping sections for the tubing sheaths and for the needle.

Another object of the present invention is to provide devices that will measure the force with which the tubing sheath and the needle are being grasped or pinched.

A further object of the present invention is to teach the method by which the grasping assemblies can be used to accomplish the object of this invention. Once the assembly already described grasps the tubing sheath, the mechanism grasping the needle is rotated, making the needle advance into the open sheath. The rotation of the advancement shaft is measured and monitored at all times. If a point is reached when maximum torque is being applied but not no substantial rotation is observed, indicating an obstruction, needle advancement is stopped. At this moment, the sheath grasp is slightly released, and the motor is reversed in direction. Insertion of the needle into the sheath is then re-attempted in order to complete the insertion.

In still another aspect of the present invention, an apparatus is provided to clamp, hold in place, and enlarge the diameter of a catheter sheath during manufacture.

It is a further object of the present invention to provide the means to control all the actions of the different mechanisms and actuators by means of an electronic microcomputer such that all the operations may be supervised and executed at the proper moment and sequence, and to the corresponding degree.

When the word “invention” is used in this specification, the word “invention” includes “inventions”, that is, the plural of “invention”. By stating “invention”, the Applicant does not in any way admit that the present application does not include more than one patentable and non-obviously distinct invention and Applicant maintains that the present application may include more than one patentable and non-obviously distinct invention.

Further, the purpose of the accompanying abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers, and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective of the apparatus of the present invention.

FIG. 2 is an end view of the puller or pusher mechanism.

FIG. 3 shows a view of the clamping and enlarging mechanism in its open position.

FIG. 4 presents an end view of the clamping and enlarging mechanism prior to pulling vacuum.

FIG. 5 is an end view of the clamping and enlarging mechanism after vacuum has been established and the catheter sheath is enlarged.

FIG. 6 shows details and how L-shaped bracket with force plate and C-shaped bracket are assembled.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, wherein like reference numerals designate the corresponding structure, part, or element, as the case may be, throughout the views, and particularly to FIGS. 1 and 5, the present invention, comprises a hinged vacuum clamp 34, having a lower part 32, and an upper part 33, a distal end, and a proximal end, wherein said vacuum clamp 34 encases a catheter sheath 23, and a needle 24 protrudes from the distal end of said vacuum clamp 34.

In the preferred embodiment of this invention, wires 31 to be threaded through the catheter sheath 23 are hooked on the needle 24. The apparatus of this invention further comprises a pusher assembly and puller assembly. The pusher and puller assembly is fully explained in FIG. 2.

In the preferred embodiment, the position of the needle 24 as to the vacuum clamp 34 is monitored by a laser light curtain transmitter 36 and receiver 37. A camera 38 is used to overlook the workspace. An Image processor 39 feeds the visual information captured by said camera 38 to an industrial computer 40, which then schedules movement through a plurality of motor controlling means 41. A sensor processor module 42 receives data from a plurality of position, rotation, force, and torque sensors, to ascertain the progress of the manufacturing step.

FIG. 2 shows an assembly of parts that are used to push or pull the needle 24 through the catheter sheath 23. Said pusher and puller assembly comprising a slider stage, having a base 10 provided with a two section screw 30, wherein one half of said two section screw is right handed, and the other half of said two section screw is left handed. The two-section screw is connected to slider plates 11 such that when the screw turns in one direction the slider plates 11 are drawn apart, and when the screw turns in the opposite direction the slider plates 11 come together. A sensor 12 measures the gap between the slider plates 11. The slider stage is driven by a motor 18 having control wires 25. L-shaped brackets 13 are fixedly connected to the slider plates 11. Force plates 14 having sensor wires 27 are affixed to the L-shaped brackets. A C-shaped bracket 15 is attached to each of the L-shaped brackets so that the assembly may slide relative to the L-shaped brackets and transmit any forces applied to the force plates 14 placed in between the L and C shape brackets. Controllable motors 19 having control wires 26 are mounted on each of the C-shaped brackets. A Rotary encoder 21 and a torque sensor 22 monitor the operation so that if high torque is measured with no movement, this indicates an obstruction and proper action must be taken. A plurality of rubberized wheels 20 come into contact with the needle 24 and tubing making it advance or retract. Shafts 17 sustain the vertical rotating assemblies. Stiffening brackets 35 maintain the rotary encoder 21 and torque sensor 22 in position.

FIG. 3 shows the vacuum clamp in the open position, with connected striations visible in both the lower part 32 and the upper part 33.

FIG. 4 shows an end view of the vacuum clamp in the closed position with catheter sheath 23 prior to the establishment of a vacuum through connections 34.

FIG. 5 is another end view of the vacuum clamp, this time after the establishment of a vacuum, pulling on the catheter sheath walls and enlarging its diameter to facilitate the insertion of the needle 24 and wires 31.

FIG. 6 shows details of how the L-shaped brackets and the C-shaped brackets come together with force measurement plates 14 sandwiched in between. Wires 27 protrude from the force plate.

Thus, there has been shown and described a catheter threader which fulfills all the objects and advantages sought therefor. The invention is not limited to the precise configuration described above. While the invention has been described as having a preferred design, it is understood that many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art without materially departing from the novel teachings and advantages of this invention after considering this specification together with the accompanying drawings. For example, the particular shapes and proportions of the elements of the invention may be varied as desired. Accordingly, all such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by this invention as defined in the following claims.

All of the patents recited herein, and in the Declaration attached hereto, if any, are hereby incorporated by reference as if set forth in their entirety herein. The details in such patents may be considered to be incorporable at Applicant's option, into the claims during prosecution as further limitations in the claims to patentably distinguish any amended claims from any applied prior art. The components disclosed in the various patents, patent applications, and publications, disclosed or incorporated by reference herein may be used in the embodiments of the present invention, as well as equivalents thereof.

All, or substantially all, of the components and methods of the various embodiments may be used with at least one embodiment or all of the embodiments, if more than one embodiment is described herein.

In the claims, means-plus-function clauses, if any, are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.

Claims

1. An apparatus for the automated threading of a catheter, comprising:

a) A clamping and enlarging means;

b) A needle or conductor pusher and puller assembly having a plurality of electric motors, a plurality of rollers connected to said motors, a plurality of sensors to ascertain the progress of the manufacturing step, and opening and closing means for gripping of materials;

c) a plurality of opening and closing means for gripping threading needles or conductors within said rollers;

d) a camera disposed to overlook the workspace;

e) an image processor means;

f) a plurality of electric motor controllers;

g) an industrial computer, wherein said image processor means feeds the visual information captured by said camera to the industrial computer to monitor the progress of the manufacturing step and wherein said computer schedules movement of the different parts of the apparatus through the plurality of motor controlling means; and

h) A computer based controller with stored program means to control the entire apparatus assembly and the sequence of operations.

2. The apparatus for the threading of catheters of claim 1, wherein said sensors comprise:

a) position sensors to detect the position of the threading needle and or conductors entering and emerging from the sheath to be threaded;

b) a sensor to measure the gap between the slider plates.

3. The apparatus for the threading of catheters of claim 1, said pusher and puller assembly further comprising:

a) a slider stage having a base provided with a two section screw and being driven by a motor having control wires; wherein one half of said two section screw is right handed and the other half of said two section screw is left handed;

b) a plurality of slider plates said two section screw being connected to said slider plates such that when the screw turns in one direction the slider plates are drawn apart, and when the screw turns in the opposite direction the slider plates come together;

c) a plurality of L-shaped brackets fixedly connected to the slider plates;

d) Force plates having sensor wires and being affixed to the L-shaped brackets;

e) A C-shaped bracket attached to each of the L-shaped brackets so that the assembly may slide relative to the L-shaped brackets and transmit any forces applied to the force placed in between the L and C-shaped brackets;

f) Controllable motors having control wires and being mounted on each of the C-shaped brackets;

g) A rotary encoder and a torque sensor to monitor the operation so that if high torque is measured with no movement this indicates an obstruction and proper action must be taken;

h) A plurality of rubberized wheels in contact with the needle and tubing making it advance or retract;

i) A plurality of shafts for sustaining the vertical rotating assemblies;

j) Stiffening brackets for maintaining the rotary encoder and torque sensor in position;

4. The apparatus for the threading of catheters of claim 1, wherein said clamping and enlarging means is supplied with vacuum means for straightening and facilitating the threading of cables, wires, or fluid conductors through the catheter sheath.

5. The apparatus for the threading of catheters of claim 4, wherein:

a) said clampling and enlarging means is a hinged vacuum clamp, having a lower part, and upper part, a distal end, and a proximal end; said distal end and said proximal end each having a protrusion through which a needle may be inserted;

b) said vacuum clamp is disposed so as to be able to encase and enlarge a catheter sheath device.

6. A method of using the apparatus for the threading of catheter of claim 1, comprising the steps of:

a) Clamping and enlarging the catheter sheath with the vacuum clamping means;

b) Passing a threading needle through the sheath by using the pusher and puller assembly;

c) Monitoring the pushing torque, rotational movement, and pinching forces with a supervisory and control microcomputer;

d) Monitoring the status of the manufacturing step with said supervisory and control computer and making decisions based on the information gathered by the sensors.

7. A clamp device for clamping and enlarging a catheter sheath, comprising:

a) A hinged clamp having a lower part, an upper part, a distal end, and a proximal end; said distal end and said proximal end each having a protrusion through which a needle may be inserted said clamp having vacuum means for straightening and facilitating the threading of cables, wires, or fluid conductors through the catheter sheath a hinged vacuum clamp; and

b) said clamp being disposed so as to be able to encase and enlarge a catheter sheath device.

8. The clamp device of claim 7, wherein said vacuum clamp includes connected striations visible in both the lower part and the upper part.