Abstract: There is provided a magnet system for generating a homogeneous magnetic field in a target region. The magnet system comprises: a first magnet formed from low temperature superconductor, LTS, material wound so as to define a central axis, the first magnet being arranged in use to generate a first magnetic field in the target region located upon the central axis, the first magnetic field having a first level of homogeneity; and a second magnet formed from high temperature superconductor, HTS, material and arranged in use to generate a second magnetic field in the target region, the second magnetic field having a second level of homogeneity.

Abstract: An electrosurgical apparatus for coagulating tissue comprises an elongated tube (6) having a tubular wall (13) and a proximal end and a distal end, and an elongate sheath (3) into which the tube (6) is inserted. The tube constites a conduit (11) though which ionisable gas can be supplied to the distal end of the tube. The tube includes one or more apertures (20) in the tube such that the ionisable gas is capable of exiting the tube in the region of the distal end of the tube. An intermediate sleeve (14) is provided into which the elongated tube (6) is inserted, and a tube handle (17) is attached to the proximal end of the tube. A sleeve handle (18) prevents the sleeve (14) from rotating, such that actuation of the handle (17) causes the flexible elongated tube to rotate within the intermediate sleeve (14).

Abstract: An electrode is for use in an electrosurgical probe, the electrode having two arms defining a longitudinal direction. The electrode also includes a loop depending from the two arms and defining a cutting area within the loop, and a vaporization member attached to one side of the loop. The vaporization member is such that it does not occlude the cutting area and yet presents a substantial profile when the electrode is moved in the longitudinal direction. The arrangement is such that when the electrode is moved in a first longitudinal direction, the loop is capable of resecting a sample of tissue. When the electrode is moved in the opposite longitudinal direction, the vaporization member is capable of vaporizing tissue adjacent thereto to form a groove therein.

Abstract: An electrosurgical instrument includes a pair of opposing first and second jaw members (5), (6) movable from a first open position in which the jaw members are disposed in a spaced relation relative to one another, to a second closed position in which the jaw members cooperate to grasp tissue therebetween. A first sealing electrode (7) is located on the first jaw member, and a second sealing electrode (8) is located on the second jaw member. A stationary flexible cutting electrode (11) is located adjacent the throat area constituted by the convergence of the first and second jaw members when in their open position. The electrical connections of the instrument are such that when the jaw members (5), (6) are in their closed position with tissue grasped therebetween, the instrument is capable of sealing the tissue by passing an electrosurgical current into the tissue from the first and second sealing electrodes (7), (8).

Abstract: An electrosurgical apparatus for coagulating tissue includes an elongated tube having a tubular wall and a proximal end and a distal end, and constituting a conduit though which ionisable gas can be supplied to the distal end of the tube. The tube includes one or more apertures in the tube such that the ionisable gas is capable of exiting the tube in the region of the distal end of the tube. A braided tubular component is associated with the wall of the tube, and is connected to a source of electrosurgical energy, such that the braided tubular component can form part of an electrode assembly for ionising the ionisable gas exiting the one or more apertures.

Abstract: An electrode is for use in an electrosurgical probe, the electrode having two arms defining a longitudinal direction. The electrode also includes a loop depending from the two arms and defining a cutting area within the loop, and a vaporisation member attached to one side of the loop. The vaporisation member is such that it does not occlude the cutting area and yet presents a substantial profile when the electrode is moved in the longitudinal direction. The arrangement is such that when the electrode is moved in a first longitudinal direction, the loop is capable of resecting a sample of tissue. When the electrode is moved in the opposite longitudinal direction, the vaporisation member is capable of vaporising tissue adjacent thereto to form a groove therein.

Abstract: A superconducting magnet system comprises a cryogenic vessel (1), a superconducting magnet (11) contained in an inner reservoir (16) within the vessel (1) to be cooled by liquid helium within the inner reservoir (16), and an outer reservoir (7) containing liquid helium and linked to the inner reservoir (16) by a feed tube (10) and a needle valve (9). In operation of the system current is supplied to the magnet (11) by a removable current lead (19) extending through the wall of the vessel (1) by way of a supply passage (17) in order to initiate superconducting current flow in the magnet. The supply of current to the magnet (11) is then stopped and the lead (19) is removed whilst the superconducting current flow persists in the magnet. After an extended period of superconducting current flow in the magnet (11) and without stopping such superconducting current flow, liquid helium at a temperature of about 4.

Abstract: A superconducting electromagnet apparatus comprises a main coil assembly (1) and a main current supply (5) energising and de-energising the main coil assembly (1), and for persisting the current flow in the main coil assembly (1) when a desired constant current level has been reached, in order to generate a central magnetic field of high homogeneity in a working volume. The apparatus further comprises a B0 shim coil assembly (2) comprising superconducting shim coils connected within a closed loop and arranged to magnetically couple with the main coil assembly (1) and an auxiliary current supply (6) for supplying current to the closed loop, and for persisting the current flow in the closed loop when a desired constant current level has been reached, in order to provide fine adjustment of the central magnetic field within the working volume without significantly degrading the homogeneity of the central magnetic field.

Abstract: A cryosurgical probe comprises a probe head operable to be cooled by the expansion of a refrigerant gas within the probe head; a probe handle having means for precooling the refrigerant gas; and a flexible catheter linking the probe handle and the probe head, the catheter defining a channel for carrying precooled refrigerant gas from the probe handle to the probe head.

Abstract: The device displays an hour hand and a minute hand on a twelve hour dial and comprises a layer of electro-optical material having on one face an inner ring of 10 sectorial plate electrodes B.sub.1 etc, each subtending an angle of 36.degree. and a corresponding outer ring of 10 plate electrodes B.sub.11 etc. On the other face there are sixty radial segments electrodes arranged in ten groups of six segments. Each group is opposed to a respective one of the ten plates. The segments are connected in six meandering circuits M.sub.1 to M.sub.6 so that, in proceeding one way round the dial, the segments of the said groups pertaining to the circuits M.sub.1 to M.sub.6 and then to the circuits M.sub.6 to M.sub.1 and so on in alternation round the dial.