Patent Number: 041467965
Section: claims

1. An apparatus for determining the depth of a radiation source within a body of material and transforming the same into a signal for computer usage comprising: a. radiation source holder transporting the radiation source within the body;  b. plurality of switches having contacts which are fixed in relation to the movement of said radiation source transported by said radiation source holder;  c. trigger means for indicating the activation of any of said plurality of switches, corresponding to preselected depths of the radiation source within the body; and  d. means for indicating the activation of any of said plurality of switches, said indicating means producing a characteristic signal determinative of the activation of any of said plurality of switches which corresponds to the depth of the radiation source within a body and including detection means for distinguishing said characteristic signals and associating the same with the activation of any of said plurality of switches. 2. The device of claim 1 in which said trigger means produces a magnetic field and said switches are activated by said trigger means magnetic field. 3. The apparatus of claim 2 in which said trigger means is affixed to said radiation source holder and is movable therewith. 4. The apparatus of claim 3 in which said apparatus additionally includes means for guiding said radiation source holder within the body. 5. The device of claim 4 in which said guiding means interposes said trigger means and said plurality of switches. 6. The device of claim 1 in which said indicating means comprises a series of resistors electrically linked to a source of power, said plurality of switches connected to an electrical ground, each of said plurality of switches connected between each of said resistors, and said means for distinguishing said characteristic signals produced by the circuit formed by said ground, any of said plurality of switches, a selected number of said series of resistors and said power source. 7. The device of claim 6 in which said trigger means is affixed to said radiation source holder and is movable therewith. 8. The device of claim 7 in which said apparatus additionally includes means for guiding said radiation source holder within the body. 9. The device of claim 8 in which said guiding means interposes said trigger means and said plurality of switches. 10. The device of claim 9 in which said trigger means produces a magnetic field and said switches are activated by said trigger means magnetic field.