GB2138687A

GB2138687A - Method and apparatus for deflecting the tip of an endoscope

Info

Publication number: GB2138687A
Application number: GB08409168A
Authority: GB
Inventors: Walter P Siegmund
Original assignee: Warner Lambert Technologies Inc
Current assignee: Warner Lambert Technologies Inc
Priority date: 1983-04-29
Filing date: 1984-04-09
Publication date: 1984-10-31
Also published as: DE3415771A1; GB8409168D0; CA1222670A; JPS59225034A; FR2544978A1; GB2138687B

Abstract

An endoscope comprises a housing connected to a flexible shaft enclosed in a sheath terminating in an articulated tip, the sheath having a sufficient reaction to torque that a twisting moment at the housing end causes the tip of the sheath to rotate about the longitudinal axis on the shaft. A single pair of control cables are used to deflect the distal end of the endoscope whilst the sheath is rotated to the desired angular position. <IMAGE>

Description

SPECIFICATION Method and apparatus for deflecting the tip of an endoscope The present invention relates to endoscopes and relates in particular to those scopes having a shaft whose distal end or tip is articulated and deflectable under control of remotely located manually or automatically operated dials, levers or knobs.

Typical controls include pairs of wires or cables connected to rack and pinion sets or reels or drums where one end of each wire is connected internally to the scope tip and opposite ends are individual to a rack. In the use of drums or reels, pairs of wires are connected to the drums diametrically opposite one another. Rotation of a pinion or of a drum in oscillatory fashion operates to tension one wire while slacking the other wire of a given pair with the result that the articulated tip of the scope is deflected.

The language "rack and pinion set" is intended to denote two racks each mating with a single pinion so that oscillation of the pinion drives one rack in a first direction while the other rack is driven in the opposite direction.

Where it is desired to have capability to deflect a tip polydirectionally or universally, two pairs of cables are utilized; each pair of cables is individual to a rack and pinion set or to a drum, as the case may be.

The apparatus (which can be operated manually or automatically) for slacking and tensioning pairs of cables is a matter of engineering and design choice and, in the subsequent description and claims, the apparatus for slacking and tensioning pairs of cables may be referred to as "cable tensioning means".

One tensioning means deflects the tip in a first plane while the other deflects in a second plane perpendicular to the first plane and if one combines the action of both tensioning means, deflection of any desired angle can be achieved within the quadrants of the perpendicular planes.

A representative embodiment of a prior art endoscope disclosing tensioning means in the form of two pairs of cables and associated rack and pinion sets with control dials or knobs is disclosed and described in U.S. Patent No.

4,207,873 entitled ENDOSCOPE DEFLECTION CONTROL issued to Theodore A. Kruy on June 17, 1980, and assigned on its face to American Cystoscope Makers, Inc.

A primary feature of the present invention is to present a method and an apparatus for manipulating or deflecting the distal end or tip of an endoscope universally through all points on the periphery of a circle whose center falls on the longitudinal axis of a straight undeflected endoscope shaft using only one pair of cables or wires, i.e., one cable tensioning means.

Stated otherwise, it is a primary feature of the invention to provide a method and apparatus for deflecting an endoscope tip polydirectionally by means of a single pair of wires connected to a single rack and pinion set, a single drum or equivalent winding or reeling device.

A further feature of the invention is to provide simplified endoscope structure and operation permitting the operator additional freedom to manipulate manually other pertinent endoscope controls.

A further feature of the invention is to provide a method of deflecting the tip of the scope polydirectionally by rotating the scope sheath relative to the body of the scope.

The language "sheath" is intended to define a protective cover or armor which surrounds the cables and is a part of the scope shaft.

A further feature of the invention is the provision of a deflection control operable by the same hand which grasps the body of the scope.

A still further feature of the invention is that the improved scope disclosed and claimed lends itself to mounting upon a tripod in stable fashion so thai a camera may be incorporated facilitating photographing the particular area in which the scope can be operated from a remote location scope cna be operated from a remote location using electrically powered cables.

That is, deflection of the distal end of the scope can be accomplished while the scope housing remains fixed to a tripod and universal or polydirectional deflection is accomplished with a single pair of cables.

An apparatus embracing certain features of the invention may comprise an endoscope having a housing, a shaft having a sheath terminating in a tip, said tip being deflectable by a pair of cables within the sheath under the control of a cable tensioning means contained within the housing where oscillation of the tensioning means is effective to tension one cable and slack the other deflecting the tip, bearing means for coupling the sheath to the housing so that the sheath is rotatable relative to the housing, cable control means connected to said tensioning means for oscillating the tensioning means to deflect the tip in a given plane, and sheath control means for rotating the sheath relative to the housing to effect deflection of the tip polydirectionally in the manner of a universal joint.

A method incorporating principles of the invention and practiced by the operation of the above apparatus to deflect the tip or distal end of an endoscope polydirectionally utilizing a single pair of control cables manipulated by oscillation of a single control knob may comprise the steps of providing an endoscope including a head or housing connected to a flexible shaft protected by a sheath terminating in a tip, said sheath having a sufficient reaction to torque such that a twisting moment at the head end of the sheath will rotate the tip of the sheath proportionally about the longitudinal axis of the shaft, providing a bearing between the housing and the sheath so that the sheath and the housing are relatively rotatable, rotating the housing end of the sheath relative to the housing through a desired angle to impart proportional rotation to the distal end or tip thereof, and manipulating the control knob to deflect the distal end of the shaft while the shaft remains rotated at said desired angle.

Other features and advantages will become more apparent from an examination of the succeeding specification when read in conjunction with the appended drawings, in which: Fig. 1 is a perspective view of a prior art device showing a pair of control knobs or dials each actuating a separate pair of cables; Fig. 2 is an enlarged horizontal sectional view of Fig. 1 as observed in the plane represented by the line 2-2; Fig. 3 is a side view of a first embodiment of the invention showing a scope housing fitted with a pistol grip and lever for rotating the sheath relative to the housing; Fig. 4 is a side view showing an alternate embodiment suitable for mounting upon a tripod; and Fig. 5 is a side view of a further embodiment showing a pistol grip, deflection control lever, shaft rotator and focus wheel with parts broken away for clarity.

Referring now to the drawings, in particular Fig.

1, a prior art scope 10 includes a housing 1 1 fixed to shaft 12 terminating in a distal end or tip 13 deflectable to various dotted line positions 14 and 16 by manipulation of two deflection control dials 17 and 18 having individual coaxial shafts 19 and 21. Shaft 19 operates pinion and rack set 22 and shaft 21 operates pinion and rack set 23.

Thus, in the prior art device of Figs. 1 and 2, it is necessary to manipulate two rack and pinion sets 22 and 23 to obtain universal or polydirectional deflection of tip 13.

In contrast, a reference to Figs. 3 through 5 reveals that the device of the present invention accomplishes polydirectional deflection by means of a single rack and pinion set 24 shown schematically in Fig. 5.

The various embodiments of applicant's scope include a housing 26, rotatable coupling 27 (bearing means), shaft 28, sheath 30, deflection control 29 (cable control means), pistol grip 31 (no pistol grip in the Fig. 4 embodiment), focus wheel 32 (Fig. 5 embodiment only), sheath rotator 33 (sheath control means) and distal end or tip 34.

As is most apparent in Fig. 5, the housing 26 contains a single pair of racks 36 and 37 (tensioning means) each connected and individual to cables or wires 38 and 39. Mating pinion 41 drives the racks 36 and 37 in resposne to oscillation of deflection control 29 which, in the Fig. 5 embodiment, is finger lever 42. In the embodiments of Figs. 3 and 4, the deflection control is a dial 45.

The pinion 41, in turn, oscillates to tension or slack cables 38 and 39 to deflect the distal end or tip 34 in a single plane in a manner which is well known.

It is to be understood that the rack and pinion set disclosed is merely representative of cable tensioning means and it is entirely within the scope of the invention to use a drum or other equivalent winding and reeling devices to slack and tension a pair of cables, as desired.

In all embodiments of the invention, the sheath or casing 30 of the shaft 28 makes a rotatable connection with the housing 26 as at 46 and the sheath is provided with manually operable rotator means 33 for rotating the sheath relative to the housing defining a rotation lever 47 in Figs. 3 and 5 and a serrated cone 50 in Fig. 4.

Note that the Fig. 4 embodiment is formed with a flat 55 and a lug 60 to facilitate tripod mounting.

The cables 38 and 39 and other optical and mechanical instrumentalities normally contained within the sheath are loosely contained within the sheath and are fixed to the sheath only at the distal end or tip 34.

The sheath, usually constructed of polymeric materials suitably reinforced with metallic helical coils and braiding, provides sufficient rigidity and resistance to torsibnal loads such that rotation of the sheath adjacent the housing will result in proportional rotation of the tip 34.

Thus, the combined manipulation of the finger lever 42 or the dials 45, as the case may be, in combination with rotation of the sheath by grasping rotation lever 47 or serrated cone 50 effects universal or polydirectional deflection of tip 34 using only one rack and pinion set.

In summary, the method of obtaining universal or polydirectional deflection of the distal end of an endoscope using a single cable tensioning means is effected by providing a rotating joint between the scope housing and the sheath so that manipulation of the single cable tensioning means (a single pair of cables) in combination with rotation of the sheath provides infinite peripheral swing about the longitudinal axis of the scope shaft.

Claims

1. A method of deflecting the tip or distal end of an endoscope polydirectionally utilizing a single pair of control cables with cable tensioning means comprising the steps of: providing an endoscope including a housing connected to a flexible shaft enclosed in a sheath terminating in an articulated tip, said sheath having a sufficient reaction to torque such that a twisting moment at the housing end of the sheath will rotate the tip of the sheath proportionally about the longitudinal axis of the shaft, providing a bearing between the housing and the sheath so that the sheath and the housing are relatively rotatable, rotating the housing end of the sheath relative to the housing through a desired angle to impart proportional rotation to the distal end or tip, and actuating the tensioning means to deflect the distal end of the endoscope while the sheath is rotated to desired angular positions.

2. A method of deflecting variably the tip or distal end of an endoscope utilizing a single pair of cables with cable tensioning means actuated by oscillation of a single control knob comprising the steps of: providing an endoscope including a housing connected to a flexible shaft enclosed in a sheath terminating in an articulated tip, said sheath having a sufficient reaction to torque such that a twisting moment at the housing end of the sheath will rotate the tip of the sheath proportionally about the longitudinal axis of the shaft, providing a bearing between the housing and the sheath so that the sheath and the housing are relatively rotatable, rotating the housing end of the sheath relative to the housing through a desired angle to impart proporitonal rotation to the distal end or tip, and oscillating the control knob to deflect the distal end of the shaft while rotating the housing end of the sheath to effect variable deflection of the tip.

3. In an endoscope having a housing of the type having a shaft enclosed in a sheath terminating in a tip, said tip being deflectable by a pair of cables under the control of cable tensioning means contained within the housing where actuation of the tensioning means operates to tension one cable and slack the other deflecting the tip, the improvement comprising: bearing means for coupling the sheath to the housing so that the sheath is rotatable relative to the housing, cable control means for actuating the tensioning means to deflect the tip in a given plane, and sheath control means for rotating the sheath relative to the housing while actuating the cable control means to effect deflection of the tip polydirectionally in the manner of a universal joint.

4. The endoscope of Claim 3 in which stop means are formed at the junction of the housing and the sheath to limit the relative rotation between the sheath and the housing.

5. The endoscope of Claim 3 in which the housing is formed with a pistol grip.

6. The endoscope of Claim 5 in which the cable control means is a lever formed with a loop for receiving digits of a single hand grasping said pistol grip.

7. The endoscope of Claim 3 in which the sheath control means defines a pin projecting from said sheath adjacent the junction between the sheath and the housing.

8. The endoscope of Claim 3 in which the sheath control means defines a knurled grip formed on the sheath.

9. The endoscope of Claim 6 in which the housing supports a focus wheel positioned adjacent said pistol grip whereby the lever and the focus wheel are all freely manipulated manually by a single hand grasping the pistol grip.

10. In an endoscope having a housing connected to a shaft terminating in a tip, said tip being deflectable by a pair of cables under control of cable tensioning means contained within the housing where actuation of the tensioning means operates to tension one cable and slack the other deflecting the tip, the improvement comprising: cable control means for actuating said tensioning means accessible manually by the same hand by which one grasps the pistol grip.

11. The endoscope of Claim 10 in which the cable control means defines a lever formed with a loop for receiving digits of a single hand grasping said pistol grip.

12. An endoscope substantially as herein described with reference to the accompanying drawings.