The present invention relates to endoseopic surgery training apparatus particularly, but not exclusively, laparoscopic training apparatus.

Surgeons performing operations using endoseopes. for example laparoscopic surgeons, require skills different fro those required in traditional surgery. In performing a laparoscopic operation a surgeon will have to manipulate fibre-optic light sources and/or endoseopes as well as his/her miniaturised operating instruments whilst referring to an enlarged television image of the part of the body on which the operation is being performed. Often the tools may be of specialised design (e.g curved needles) or may have pivoting parts that require skill and dexterity to manipulate. The spatial motor skills required to perform such operations unish need practice and honing before competent real operations can be conducted. However, since the equipment used to perform laparoscopy comprises a video camera with Iaparoscope, a processor and a television it is generally not economically viable to make it available for training purposes or to have a second set of equipment available for the same purpose. Accordingly there is a demand for relatively cheap laparoscopic training apparatus that simulates the conditions under which laparoscopy is performed.

According to the present invention there is provided endoseopic surgery training apparatus comprising a work surface positioned between first and second opposed reflective surfaces and a screen adjacent said work surface, wherein the reflective surfaces are arranged such that an image of the work surface is reflected by said first reflective surface to said second reflective surface so that an image of the work surface corresponding to the same orientation as the work surface can be viewed in the second reflective surface from a position behind the screen in which a direct view of the work surface is obscured by the screen.

The apparatus thus enables a user to view a workpiece on the work surface and the ends of his tools or instruments around the workpiece, through the second reflective surface thus simulating the view he would see on a television screen if endoseopic equipment is used. The image is in the correct orientation as compared to

the actual workpiece as would be the case when viewing the endoscope television screen.

Conveniently the screen has apertures through w hich operating tools or instruments may be inserted to reach the work surface.

The first and second reflective surfaces are preferably planar and concave mirrors respectively. The concave mirror provides an enlarged image for the user to view to simulate the enlarged view that would be provided by an endoscope television screen.

The first reflective surface be mounted on screen and the second reflective surface may be mounted on a wall opposite the screen.

Preferably the orientation of the reflective surfaces are adjustable to ensure that a desired image desired is reflected to user ^' s eye.

The work surface may be mounted on a base that supports the screen and the opposite wall.

Preferably the work surface is moveable between different positions on the base and releasable fixing means may be provided to secure it relative to base during use.

The screen and opposite wall may be collapsible and preferably the base has side walls so that they are collapsible into the base to form a box. Preferably the screen and opposite wall are pivotally connected to the base. In addition the work surface may be collapsible and stowable in the box.

Support means may be provided to ensure w all and screen remain in upright configuration during use.

A securing strap or web may conveniently be provided on the box to releasably secure the apparatus in the collapsed coniiguration and/or to be used as a handle.

A specific embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a laparoscopic trainer in a collapsed configuration.

Figure 2 is a perspective view of the laparoscopic trainer of figure 1 shown in an erect configuration.

Figure 3 is a cut away view in the direction of arrow Λ in figure 2.

Referring now to the drawings, a laparoscopic trainer being an example of the present invention is shown in a collapsed box configuration for storage purposes (figure 1) and an erect configuration in which it is used (figures 2 and 3).

The trainer comprises a box base 1 over which a box lid 2 fits in a snug relationship. The lid has a pair of opposed side walls 3 that are tapered at one open end 4 and bridged at the other an end wall 5. The base 1 has side walls 5 which taper downwardly at both ends 7 to meet with end w alls 8 that are of reduced height. Pins 9 that pass through apertures in the side walls 3.6 of the lid 2 and base 1 pivotalh connect the base 1 to the lid 2 at one end so that it can be moved through 90 degrees between a stowed position in which it receives the base 1 (figure 1 ) and an upright configuration as shown in figures 2 and 3.

Pivotally connected to the base 1 at the opposite end to the lid 2 the lid is a screen 10. The screen 10 is of the same shape as the lid 2 but slightly smaller in dimension so that it may be enclosed, in the collapsed configuration, by the box formed by the base 1 and lid 2. It is pivotal in the same way as the lid 2 between a collapsed position (figure 1 ) and an upright position as shown in figures 2 and 3.

Mounted on the inside of the lid 2 is a planar rectangular mirror 1 1 . On the equivalent surface of the screen 10 there is hingedly mounted a concave round mirror 12. The concave mirror 12 is fitted in a frame 13 the bottom edge 14 of which is connected to the screen by means of a hinge (not shown) so as to permit it to tilt relative to the upright. Between the rear of the mirror frame 13 and the screen 10 there are fitted restraining straps 15 that limit the degree of tilt of the mirror 12 to the upright.

Below and between the two mirrors 1 1 , 12 there is a platform 16 is supported on the base 1. The platform 16 comprises a planar work surface 1 7 that is parallel to the bottom surface of the base 1. The work surface 17 is supported at one end by an

integral web 18 and at the other by a ledge 19 defined on the screen 10. The platform 16 may be moveable between different positions relative to the supporting base 1 .

The screen 10 has two parallel elongate vertical slits 20 on each side and below the concave mirror 12. Bach slit 20 comprises an aperture in the screen that is lined with a vertically slitted foam-like material. The foam-like material is resiliently flexible so that in use a surgeon may pass his/her tools through the slits at a selected angle without being able to see through the apertures.

The apparatus is provided with rigid elongate supports panels 21 that are designed to support the screen 1 in the upright position. One end of each panel 21 has a taper 22 that is complementary to tapers (hidden ) on side walls 23 of the screen 1 0 . In the erect configuration of the apparatus the support panels 21 are placed inside the base 1 adjacent the side walls 6 of the base 1 so that the tapered part 22 of each panel 21 wedges under the tapered part on the respective side wall 23 of the screen 10. In this position the screen 10 is prevented from pivoting towards the base 1 by the presence of the panels 21.

In use a trainee will practice a surgical operation or manoeuvre on a workpiece placed on the platform work surface 1 7. The trainee stands behind the screen 10 with the apparatus in front of him in a position where his direct view of the workpiece is obscured by the screen 10 but his direct view of the planar mirror 1 1 is not. By adjusting the tilt of the concave mirror 12 the trainee will be able to see an image of the workpiece in the planar mirror 1 1 by looking over the screen 10. The operation or manoeuvre is performed on the workpiece by inserting tools (not shown) through the slits 20 in the screen 10 and presenting them to the workpiece whilst looking in the planar mirror 1 1. The tools may be inserted at selected angles to the screen to enable the trainee to practice manipulating the tools under different conditions. The image seen by the trainee will be in the correct orientation thereby assisting him to manipulate the tools in the correct direction. Since the concave mirror 12 provides an enlarged image of the workpiece the view in the planar mirror 1 1 simulates the image that would be seen on the television when using laparoscopic equipment.

Suitable workpieces can be selected to enable practice of general manipulative skills or particular techniques. The work surface 1 7 may be covered with a cork or foam layer so that manoeuvres involving sewing or pinning to the surface items such as fabric can be practised.

Ends of the side walls 6 of the base 1 and lid arc tapered at 7 and 24 to permit the latter to be pivoted into the storage configuration when the apparatus is on a flat surface without clashing with the surface or interference between the parts of the apparatus. Similar tapers (hidden) arc present on the side walls 23 of the screen 10.

In the storage configuration the lid overlies the screen 10 and base 1 and may be releasably secured to the base by means of ^" a strap 25 that slips over the base 1 as shown in figure 1. The strap may also be used as a carrying handle.

The outersurface of the screen 10 may be provided with a ring 26 by which it may be pivoted out of the base 1 into the upright position.

It will be understood that while the above apparatus has been described in relation to laparoscopy it will have application to any surgery in which endoseopic devices are used and the surgeon performs the operation by reference to an image on a screen.