Abstract: The magnetic shield preferably encloses circuitry connected to equipment in a high magnetic field (e.g., two transformers of a gas flow transducer in an MRI suite). The magnetic shield is preferably oriented so that its long axis is aligned with the axis of maximum magnetic sensitivity of the enclosed circuitry. The shield shunts external magnetic flux around the enclosed circuitry to protect the circuitry from saturation in the high magnetic field. The shield is preferably made from hot rolled low carbon steel which has relatively low permeability and saturates slowly. The physical size and construction of the shield reduces magnetic flux within the shield with a minimal amount of iron. In another embodiment, a magnetic field sensor is mounted within the shield to measure the magnetic field affecting the enclosed circuitry. The sensor is coupled to an external circuit which indicates when the magnetic flux is strong enough to affect the operation of the enclosed circuitry.

Abstract: The magnetic shield preferably encloses circuitry connected to equipment in a high magnetic field (e.g., two transformers of a gas flow transducer in an MRI suite). The magnetic shield is preferably oriented so that its long axis is aligned with the axis of maximum magnetic sensitivity of the enclosed circuitry. The shield shunts external magnetic flux around the enclosed circuitry to protect the circuitry from saturation in the high magnetic field. The shield is preferably made from hot rolled low carbon steel which has relatively low permeability and saturates slowly. The physical size and construction of the shield reduces magnetic flux within the shield with a minimal amount of iron. In another embodiment, a magnetic field sensor is mounted within the shield to measure the magnetic field affecting the enclosed circuitry. The sensor is coupled to an external circuit which indicates when the magnetic flux is strong enough to affect the operation of the enclosed circuitry.

Abstract: A laryngoscope constructed of materials including metal components having very low magnetic susceptibilities is described. The battery powering the laryngoscope lamp is a lithium battery also constructed of materials having low magnetic susceptibilities. The battery further includes a unique terminal configuration that prevents the inadvertent use of other batteries, including non-magnetic batteries, in the laryngoscope. A unique lamp retaining mechanism provides for quick and easy replacement of the lamp.

Abstract: A penlight constructed of materials including metal components having very low magnetic susceptibilities is described. The battery powering the penlight lamp is a lithium battery also constructed of materials having low magnetic susceptibilities. The penlight is particularly useful in the vicinity of the strong magnetic field of an MRI scanner.

Abstract: A laryngoscope constructed of materials including metal components having very low magnetic susceptibilities is described. The battery powering the laryngoscope lamp is a lithium battery also constructed of materials having low magnetic susceptibilities. The battery further includes a unique terminal configuration that prevents the inadvertent use of other batteries, including non-magnetic batteries, in the laryngoscope. A unique lamp retaining mechanism provides for quick and easy replacement of the lamp.

Abstract: A new duplicating carving machine that will allow individuals to easily and accurately carve wooden propellers, musical instruments, sculpture or other items. The invention has a unique and rigid carving mechanism, having a stylus and motorized cutter mounted upon a rigid "U"-shaped frame, combined with a simple and accurate alignment system, in which the U-frame pivots upon a transverse bar which is aligned upon side rails in the manner of a T-square, enabling the duplicator to easily and accurately carve a propeller or other item from a three-dimensional master. The duplicating carver of the invention is very simple to set up and operate, and includes a novel brake mechanism to stabilize the cutting motion. The average craftsman will be able to quickly and precisely shape a workpiece--any design from violin faces, electric guitar bodies or scroll work on cabinet doors, to airplane propellers, to name only a few. Only sanding is required to achieve the finished shape.

Abstract: There is provided a propulsion unit that is incorporated in an endoscope or borescope. Advancement of the insertion tube through a passageway is attained by a series of washers or similar members that can be mounted on the insertion tube of the borescope and can independently move coaxially with respect to the insertion tube. When the tube is passed into a passageway, the washers contact the walls. A drive motor that is associated with the insertion tube axially reciprocates the washers and transmits the axial motion to the insertion tube. The rate of movement of the washers is nonuniform and washer movements are phased such that at any point in time more washers are moving in one direction than in the opposite direction. The resultant frictional forces are such that net forward motion of the tube is achieved.

Abstract: An instrument for penetrating a small opening for closely examining an interior target. The instrument has a narrow needle probe that forms an image of the target and carries it into a main housing. In the housing, a miniature solid-state imager receives the image and forms a video signal that is transmitted, through a long flexible conduit, to a video monitor. The probe is formed of a steel tubular sleeve containing a self-focusing rod lens. A fiber optic bundle surrounds the rod lens to carry illumination to the end of the sleeve for illuminating the target area. A guide tube can be affixed on the sleeve to guide a tool into the target area.

Abstract: A video hysteroscope has an elongated flexible insertion tube containing a video imager head at its distal end, with a channel for a surgical laser fiber and a saline channel which emits a continuous stream of saline solution distally from the head. The articulation section is kept as short as possible, and is limited to a maximum deflection of about 30 degrees to match the geometry of the uterus.

Abstract: A steering section for an endoscope or borescope employs a plurality of steering cables that pass through peripheral bores of axially aligned flat washers. Spacer beads are strung on the cables between the washers to define hinge points for the bending of the steering section. The spacer beads are tapered beads having a relatively wide base and relatively small, flat nose surface. A through-passage in the bead has a relatively narrow nose portion with a small clearance with respect to the steering cable, and a tapered or countersunk portion that expands basewards and prevents the spacer bead from binding the cable.

Abstract: A steering section for an endoscope or borescope employs a plurality of steering cables that pass through peripheral bores of axially aligned flat washers. Pairs of beads are strung on the cables between the washers to define hinge points for the bending of the steering section. Each pair of beads include a spherical-nose ball bead and a countersunk socket bead. A through-passage in the ball bead has a relatively narrow nose portion with a small clearance with respect to the steering cable, and a tapered or countersunk portion that expands basewards and prevents the spacer bead from binding the cable. The axial bores in the washers are tapered out fore and aft from a relatively narrow waist portion so that the cable touches the washer only at a single point. Limiter beads of about half the thickness of the spacing between washers limit the bending of the steering section.

Abstract: A self-adjusting mechanism ensures that the collective force on the steering cables of an endoscope or borescope is limited or relieved when a predetermined force is reached. The mechanism includes a frame, a slider that moves on the frame and restrains the proximal ends of the steering cable sheaths, and springs that bias the slider distally. The springs can be preloaded by employing a stop member to limit the distal movement of the slider.

Abstract: In a cable-steerable endoscope or borescope, in which opposing cables are displaced to deflect the tip of the endoscope or borescope, a self-adjusting mechanism in the control section ensures a maximal differential force and a minimal total force is applied to the two steering cables. The self-adjusting mechanism has a frame that is affixed within the control section and a slider that is slidably disposed on the frame. First and second arms project outwardly from the slider and engage ends of the cable sheaths for the steering cables. The slider has a structure that engages the frame when there is no force on one steering cable to lock the slider against sliding motion, but which permits the slider to move proximally on the frame when there are forces applied on both steering cables.