Cryosurgical device

Реферат: 1438843 Refrigeration FRIGITRONICS OF CONN Inc 22 Aug 1973 [12 Sept 1972] 39869/73 Heading F4H [Also in Division A5] A cryosurgical device comprises an elongated sealed container 20 terminating at one end in a heat conducting tip 32, a liquefied refrigerant 51 partially filling the container 20 and being under superatmospheric pressure therein, an insulating housing 10a, 10b, 10c enclosing the container 20 and exposing the tip 32, and means for venting the container 20 to atmosphere to boil off the refrigerant 51 and cool the tip 32. The housing is further insulated by an air gap 36 around it. A cap 26 is crimped over the other end of the container 20 and seals a rubber diaphragm (30), Fig. 3 (not shown). A plunger 38 is mounted in the housing part 10a and carries a hollow needle 44. Depressing the plunger 38 pushes the needle 44 through a hole (28) in the cap 26 and the diaphragm (30) and the refrigerant 51 excapes through the needle 44, a hole 46 therein, porous packing 47 in the housing part 10a and holes 13, and cools the tip 32. Alternatively, a diaphragm (50), Fig. 4 (not shown) having a central enlargement (56) and an eccentric vent (60) is used. A plunger (64) is used to push the enlargement (56) inwardly so that the refrigerant (51) may escape through the vent (60). The plunger (64) has a detent (66) for engaging a shoulder (68) to retain the valve in the open position. A retractible ball-point pen type mechanism may alternatively be used to operate the plunger (64).