GB2086792A - Gripping devices - Google Patents

Abstract

A device having a relatively high friction contact or gripping surface or surfaces providing a firm gripping action when in contact with other surfaces. Such surfaces may take the form complementary convex and concave portions or a plurality of rigid globules. Devices embodying the invention include surgical forceps, needle and blade holders, probes and polishers, where the globules may comprise tungsten carbide deposited on a titanium substrate. <IMAGE>

Description

SPECIFICATION Gripping devices This invention relates to devices (hereinafter referred to as a "device of the kind specified)" having a relatively high friction contact or gripping surface of surfaces which will provide a firm gripping action when in contact with other surfaces, as, for example, in the case of devices having co-operating jaws.

Devices, the subject of the present invention are particularly suitable for use in surgery, especially microsurgery including ophthalmology, and in these applications may take the form of, for example, a pair of forceps, a needle or blade holder, a probe or a polisher, or a combination of these instruments.

For convenience the invention will be described in respect of gripping devices such as forceps and needle or blade holders, though the invention is equally applicable to other surgical instruments as explained below.

In surgical procedures, particularly those which necessitate the use of extremely fine sutures, difficulty is often experienced in carrying out the final tying operation owing to fracture of the suture.

The fracture frequently occurs when pressure is applied by a pair of forceps used to hold the suture. Some fractures of sutures occur due to sharp edges on the sides of instruments such as forceps, but even with such instruments with rounded edges fractures do occur and in many cases the latter are due to a reduction in the tensile strength of the suture due to a change in the suture's cross-section, which is caused by pressure applied by the instrument to the suture.

Instruments as aforesaid have been made in which great care has been exercised to provide a hard smooth surface, and also particular attention has been paid to ensure that the surfaces holding the sutures meet accurately to give maximum surface contact to the suture and hence maximum friction with minimum possible applied pressure.

Other forms of surfaces of such instruments have been tried including those with grooves which are intended to provide a number of concentrated pressure points with a view to, on the one hand, gripping the suture more firmly and, on the other hand, not damaging it. Thin pieces of tungsten carbide have, for example, been brazed to the surfaces to ensure long life hardened surfaces, and, in the case of needle or blade holders, also to protect the surfaces from indentation caused by excessive pressure being applied to the holder when grasping a needle or blade, thus causing deformation of the surfaces.

In some surgical procedures, particularly in ophthalmology, substances are sometimes employed which have the "side" effect of reducing the surface friction of the suture and hence the need arises to grasp the suture even more firmly when drawing the edges of tissue together or in the actual tying operation, in the course of a surgical procedure.

With a view to reducing or eliminating the problem hereinbefore discussed and generally to improving gripping action, the present in vention provides in a first aspect thereof, a device of the kind specified in which the surface of the first jaw has a portion which is substantially concave over part of the width of the jaw in the direction of its application whilst the surface of a second jaw has a portion over part of its width in the same direction which has a convexity substantially complementary to the concavity of the surface of the first jaw.

Preferably, the jaws of the device are provided with a plurality of such portions juxtaposed in the direction of application or, for example, a suture.

The invention also provides, in a second aspect thereof, a device of the kind specified in which at least one of the gripping surfaces comprises a plurality of rigid globules.

The globules are preferably applied to the surfaces of the jaws of forceps, and needle and blade holders, and in the case of probes, to that part of the probe which is intended to contact the "probed object", for example, up to 2 cm from the tip of the surgical probe.

The area of abrasive "globule" surface on a polishing device, particularly surgical polishers will, of course, vary depending upon the shape and size of the device and the precise function it is designed to perform.

The globules may be substantially hemispherical and of fairly uniform diameter and mutual spacing, but both the size and configuration of the globules in any device may vary considerably in a random fashion.

Furthermore, it is to be understood that globules do not necessarily "stand alone" and frequently partially "run together" to form a continuous "rough" surface coating.

A typical material of the globules is tungsten carbide or preferably tungsten, which may, for example, be applied by electro-deposition to a substrate of the device consisting, for example, of titanium.

Typical sizes of substantially hemispherical globules are within the range 0.00125 mm to 0.0125 mm in diameter. A random mixture of all sizes on the contact or gripping surfaces of a device are believed to offer the best solution, and it has been shown that the jaws of forceps having such surfaces can markedly increase the gripping power exerted on, for example, a suture.

It is believed that this increase in gripping power is brought about, in the case of a suture, by it being forced around some of the projections defined by the globules, thus in creasing the area of contact between the surfaces and the suture, whereby much greater friction is provided with a lower pressure exerted on the cross-section of the suture than can be obtained by means previously proposed.

Various forms of device embodying the invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a cross-section of a pair of surgical forceps embodying the invention in the first aspect, and showing a suture in position therein; Figure 2 is a view, similar to Fig. 1, but showing a modification of the forceps of Fig.

1; Figure 3 is a fragmentary perspective view of the tip of one of the jaws of a pair of surgical forceps, needle or blade holder embo dying the invention in the second aspect; Figure 4 is a view similar to Fig. 3, but showing a modification thereof.

Figure 5 is a fragmentary perspective view of the tip of a surgical probe of circular cross section embodying the invention in the second aspect; and Figure 6 is a fragmentary perspective view of the tip of a flat blade surgical polisher embodying the invention in the second aspect.

Referring to Fig. 1, a first jaw 1 has a concave portion 2, and a second jaw 3 has a convex portion 4, complementary to the concave portion 2, so that, when the jaw 1 is closed on to the jaw 3, a suture 5 is firmly gripped therebetween.

In the forceps in accordance with Fig. 2, the gripping action exerted on a suture (not shown but intended to be placed between the jaws as shown in Fig. 1) is enhanced by the provision of two concave portions 2 in the jaw 1, and correspondingly two convex portions 4 projecting from the jaw 3 and (as in the forceps according to Fig. 1) complementary to the respective concave portions 2 with which they are adapted to cooperate.

In the case of the jaw 6 shown in Fig. 3, a plurality of tungsten carbide globules 7 have been electrodeposited on a titanium surface 8 of the jaw. The globules 7 are of substantially the same diameter, and a second jaw of the forceps, needle or blade holder (not shown but adapted to co-operate with the jaw shown) is of a configuration substantially identical to that of the jaw shown.

The jaw shown in Fig. 4 is substantially the same as that shown in Fig. 3, but in this case the globules 7 are of a random variety of sizes and smooth shapes, and also randomly spaced with respect to each other.

The end portion of the circular cross section probe shown in Fig. 5 may be treated as described above in respect of Figs. 3 or 4.

Unlike a conventional probe with smooth surface, the probe so treated is capable of exerting a gripping action on tissue which can be of considerable assistance during surgical investigation or manipulation.

in Ire some instances it has been found desirable to modify the outside jaw portion 9 of the forceps or holder (Figs. 3/4) in a similar fashion to the inside portion, so that with the jaws in the closed position, the instrument may also be used as a probe as described above.

The flat blade polisher shown in Fig. 6 may also be treated as described above in respect of Fig. 3 or 4. Preferably, however, three of the four sides of the blade carry globules of either a different size of a different range of sizes, so that each side has different frictional characteristics (abrasive properties). The fourth side of the blade is usually left untreated and smooth. Though a flat blade polisher has been shown and described, the above description may equally apply to a curved blade polisher.

It will be appreciated that, whilst the invention has been particularly described, by way of example, in its application to surgical instruments, its scope is not limited thereto and may be applied equally to other instruments where an improveå gripping action is required.

Claims (17)

1. A device of the kind specified in which he surface of a first jaw has a portion which is substantially concave over part of the width of the jaw in the direction of its application whilst the surface of a second jaw has a portion over part of its width in the same direction which has a convexity substantially complementary to concavity of the surface of the first jaw.

2. A device according to Claim 1 in which the jaws are provided with a plurality of portions juxtaposed in the direction of their application.

3. A device of the kind specified in which at least one of the gripping surfaces comprises a plurality of rigid globules.

4. A device according to Claim 3 in which the gripping surfaces are the jaws of a pair of forceps.

5. A device according to Claim 3 in which the gripping surfaces are the jaws of a needle or blade holder.

8. A device according to Claim 3 in which the gripping surface constitutes part of the probe.

7. A device according to Claim 3 in which the gripping surface constitutes part of a polisher.

8. A device according to any one of Claims 3 to 7 in which the globules are substantially hemisphencal and of fairly uniform diameter and mutual spacing.

9. A device according to any one of Claims 3 to 7 in which the size and configura tion of the globules vary considerably in a random fashion.

10. A device according to any one of Claims 3 to 9 in which the globules comprise tungsten.

11. A device according to any one of Claims 3 to 9 in which the globules comprise tungsten carbide.

12. A device according to any one of Claims 3 to 11 in which the size of the hemispherical globules lies within the range 0.00125 mm to 0.0125 mm in diameter.

13. A device according to any one of Claims 10 to 12 in which the globules are applied by electrodisposition to a substrate consisting of titanium.

14. A device of the kind specified substantially as hereinbefore described with refer- ence to Figs. 1 and 2 of the accompanying drawings.

15. A device of the kind specified substantially as hereinbefore described with refer- ence to Figs. 3 and 4 of the accompanying drawings.

16. A device of the kind specified substantially as hereinbefore described with refer- ence to Fig. 5 of the accompanying drawings.

17. A device of the kind specified substantially as hereinbefore described with reference to Fig. 6 of the accompanying drawings.