Abstract: A surgical instrument is provided for performing operations on joints, comprising an elongated hollow body; an elongated tube fixedly connected at one end to the body and adapted for insertion into a joint at a selected location; a manipulator shaft axially movable in the tube and in the body; a substantially planar cutting member on one end of the shaft; and member manipulatable by the fingers to move the shaft between a first position in which the cutting member is withdrawn within the tube and a second position in which the cutting member is extended beyond the end of the tube; the tube having a rounded closed end with a slot therethrough through which the cutting member is extended and withdrawn and effective to guide the cutting member during such movement and to restrain the cutting member against rotation during such movement and while cutting.

Abstract: A surgical instrument is provided for engaging a bony part of the human body and guiding a drill bit into a specific location in the bony part comprising, in combination, a pair of lever arms pivotably attached at a point intermediate their ends; locking means for locking the arms together in a fixed position with respect to each other; means on each arm on the same side of the pivot attachment for manipulating the arms in a swinging movement about the pivot; each arm on the other side of the pivot attachment being shaped so that the pair of arms can embrace the bony part during an operation; one of the arms carrying on one end on said other side a guide head having at least one through passage to guide a drill bit and the other arm carrying at one end on the said side an engagement head, the inner facing surfaces of the guide head and engagement head being shaped to fixedly engage said bony part, the through passage in the guide head being aligned along an axis which in the operating position of the instrume

Abstract: A cannula is provided for administration of a fluid from two separate sources of supply, such as from an infusion fluid container and an injection syringe, comprising, in combination, a housing, a fluid flow passage therethrough having two fluid inlets and one fluid outlet, one of the fluid inlets being shaped to receive delivery means of an injection device for delivery of fluid to the cannula fluid flow passage, and having a check valve therein compelling flow therethrough only in the inward direction, and means in the one inlet positioned to accept any impact of the delivery means when inserted in the one inlet, and inhibit impact injury to the check valve upon such insertion.

Abstract: A separating and filtering device for effecting sealed separation of blood into a light phase and a heavy phase within a tubular fluid sample container comprising a cup-shaped piston having a closed bottom and a permeable side wall. The piston has axially spaced first and second sealing lips adapted to sealingly engage with the inner surface of the tubular container, and the first sealing lip is deflectable to permit passage of the lighter phase past this sealing lip on movement of the cup-shaped piston downwardly, through the lighter phase, while preventing the heavier phase from such passage.

Abstract: An electrosurgical apparatus having a diathermy current generator connected to an active electrode and a two-segment inactive electrode in surface engagement with the patient includes a test and control device automatically sensing the sum of the contact impedances of the two inactive electrode segments and inhibiting the passage of the diathermy current through the patient if the sensed impedance value is too high or too low. The sensing of the contact impedances is effected at intervals during periods when no diathermy current flows and is accomplished by means of alternating current.