Apparatus and system for detecting and locating photon emissions with remote switch control

• US 5,682,888 A
• Filed: 06/13/1996
• Issued: 11/04/1997
• Est. Priority Date: 06/13/1996
• Status: Expired due to Term

• Current Assignee: Devicor Medical Products Incorporated (Danaher Corporation)
• Original Assignee: Neoprobe Corporation
• Inventors: Thurston, Marlin O., Olson, Karl W.
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): MANTIS MERCADER, ELENI M
• Application Number:
  US08/662,600
• Time in Patent Office: 509 Days
• Field of Search: 128/659, 128/654, 128/653.1, 128/662.03, 250/370.13, 250/370.01, 250/336.1, 250/361 K, 310/338
• US Class Current: 600/436
• CPC Class Codes: A61B 2017/00119 alarm; indicating an abnormal situation
• CPC Class Codes: A61B 6/4258 for detecting non x-ray radiation, e.g. gamma radiation A61B6/037 takes precedence
• CPC Class Codes: G01T 1/161 Applications in the field of nuclear medicine, e.g. in vivo counting apparatus for radiation diagnosis A61B6/00

Abstract

A probe instrument which is formed having a unitary housing with indented switch actuating surfaces intended for surgical procedures employs internally disposed piezoelectric switching components within an elongate internally disposed switch receiving channel. The forward end of the instrument supports a crystal containing detector assembly with a preamplifier and associated leads which extend within a detector signal channel spaced from the switch receiving channel and protected therefrom by a shield wall. The piezoelectric components are held in preloaded association adjacent outwardly disposed switch actuating surfaces by a dual wedge switch support assembly. An elongate cable is permanently attached to the rearward end of the housing component through the utilization of a medical grade silicone seal and relief component.

Claims

1. An instrument for detecting and locating a source of radiation emissions emanating from tissue within a body comprising:

a housing with a hand graspable surface extending between forward and rearward ends, having a switch receiving channel formed therein, said switch receiving channel having a switch contact surface and an oppositely disposed load surface, at least one switch actuating surface formed into said housing hand grippable surface opposite said switch contact surface and spaced therefrom to define a predetermined switch wall thickness effective to inwardly transmit hand generated stress;

a detector assembly coupled in sealed relationship to said housing at said forward end and including a crystal detector responsive to said emissions to provide corresponding detector outputs;

a piezoelectric switch actuable in response to said hand generated stress to derive switch signals having a pressure responsive surface and an oppositely disposed support surface positioned within said switch receiving channel, said pressure responsive surface being located in abutting adjacency with said switch contact surface;

a switch support assembly having first and second wedges exhibiting predetermined slopes and having respective mutually contacting abutting surfaces and first and second substantially parallel outer surfaces spaced apart a loading distance derived by relative positioning between said first and second abutting surfaces, said switch support assembly being positioned within said switch receiving channel intermediate said load surface and said piezoelectric switch support surface, said loading distance being selected to preload said piezoelectric switch against said switch contact surface; and

a transmission assembly coupled with said housing at said rearward end for conveying signals corresponding with said detector outputs and said switch signals to an evaluation and control system.

2. The instrument of claim 1 in which:

said housing includes a detector signal channel extending rearwardly from said forward end; and

said detector assembly includes a preamplifier circuit electrically coupled with said crystal detector and said transmission assembly and positioned to extend within said detector signal channel.

3. The instrument of claim 2 in which said detector signal channel is spaced from said switch receiving channel a distance defining a shield wall.

4. The instrument of claim 1 in which:

said housing extends along a longitudinal axis between said forward and rearward ends;

said switch receiving channel extends along said axis;

said housing includes a detector signal channel extending along said axis and spaced from said switch receiving channel a distance defining a shield wall; and

said detector assembly includes a preamplifier circuit electrically coupled with said crystal detector and said transmission assembly and positioned to extend within said detector signal channel.

5. The instrument of claim 4 in which:

said detector assembly is mounted upon said housing at a predetermined angle with respect to said longitudinal axis; and

said preamplifier is circuit board mounted and said circuit board is connected to and extends from said detector assembly into said detector signal channel.

6. The instrument of claim 4 in which:

said housing is cylindrical and includes a forward cavity extending inwardly from said forward end in communication with said switch receiving channel and said detector signal channel; and

said first wedge first outer surface is attached to said piezoelectric switch support surface and extends into said forward cavity.

7. The instrument of claim 6 in which:

said housing includes a detector signal channel extending rearwardly from said forward end; and

said detector assembly includes a preamplifier circuit electrically coupled with said crystal detector and said transmission assembly and positioned to extend within said detector signal channel.

8. The instrument of claim 7 in which said detector signal channel is spaced from said switch receiving channel a distance defining a shield wall.

9. The instrument of claim 8 in which:

said first and second piezoelectric switches generate respective first and second switch voltage signals upon the actuation thereof; and

including first and second current deriving circuits mounted within said switch receiving channel and respectively responsive to said first and second switch voltage signals to derive respective first and second said switch signals at respective first and second current levels.

10. The instrument of claim 9 in which said housing includes a rearward cavity extending inwardly from said rearward end in communication with said switch receiving channel and said detector signal channel.

11. The instrument of claim 1 in which:

said housing is cylindrical and extends along a longitudinal axis;

first and second said piezoelectric switches are mounted within said switch receiving channel and are spaced apart a predetermined distance along said longitudinal axis;

said housing includes first and second said switch actuating surfaces spaced apart said predetermined distance and aligned with respective said first and second piezoelectric switches; and

said first and second switch actuating surfaces being substantially fiat, formed as an indenture within said housing surface and separated by a rib extending perpendicularly to said longitudinal axis.

12. The instrument of claim 11 in which said rib extends upwardly from said first and second switch actuating surfaces to a top surface located below said housing hand graspable surface.

13. The instrument of claim 1 in which said first and second wedges are substantially identically dimensioned.

14. The instrument of claim 13 in which said first and second wedge abutting surfaces are inclined at a said slope of about 2 degrees.

15. A system for detecting and locating a source of photon emissions emanating from tissue within a body, comprising:

a hand manipular probe including;

a housing with a hand graspable surface extending along an axis between forward and rearward ends having a switch receiving channel formed therein, said switch receiving channel extending along said axis, having a switch contact surface and an oppositely disposed load surface, a first switch actuating surface formed as an indentation into said housing hand grippable surface opposite said switch contact surface and spaced therefrom to define a predetermined switch wall thickness effective to inwardly transmit hand generated stress, and a detector signal channel extending along said axis;

a detector assembly coupled in sealed relationship to said housing at said forward end and including a crystal detector responsive to said emissions impinging thereon to provide corresponding detector outputs, an amplifier stage within said detector signal channel adjacent said detector, responsive to said detector outputs in the presence of an applied power supply to derive count outputs at an output line extending along said detector signal channel,

a piezoelectric switch actuable in response to hand generated stress to derive a switch voltage signal, having a pressure responsive surface and an oppositely disposed support surface, positioned within said switch receiving channel, said pressure responsive surface being located in abutting adjacency with said switch contact surface beneath said fast switch abutting surface,

a current deriving circuit positioned within said switch receiving channel, having an output coupled with said applied power supply and responsive to said switch voltage signal to impose a current signal of predetermined amplitude at said applied power supply,

a switch support assembly having fast and second wedges exhibiting predetermined slopes and having respective mutually contacting abutting surfaces and first and second substantially parallel outer surfaces spaced apart a loading distance derived by relative positioning between said first and second abutting surfaces, said switch support assembly being positioned within said switch receiving channel intermediate said load surface and said piezoelectric switch support surface, said loading distance being selected to preload said piezoelectric switch against said switch contact surface;

a control assembly located remotely from said probe, having at least one function selection switch actuable to derive a function input, a power supply network for deriving said applied power supply, an input network for receiving and evaluating said count outputs to derive count associated signals, an output component responsive to an applied output signal to generate a perceptible output, a processor responsive to said function input and said count associated outputs to derive a said output signal corresponding therewith, a monitoring amplifier stage responsive to current levels of said applied power supply for providing a monitor output corresponding therewith, and a level comparator circuit responsive to a said monitor output corresponding with the presence of said current signal to derive an emulating signal corresponding with said function input and effecting said processor derivation of said perceptible output; and

an elongate flexible connector assembly coupled between said probe and said control assembly for coupling said output line with said input network and for conveying said applied power supply from said power supply network to said amplifier stage of said probe.

16. The system of claim 15 in which said flexible connector assembly is permanently connected in sealed relationship with said probe housing rearward end.

17. The instrument of claim 15 in which:

said housing includes a detector signal channel extending rearwardly from said forward end;

said detector assembly includes a preamplifier circuit electrically coupled with said crystal detector and said transmission assembly and positioned to extend within said detector signal channel.

18. The instrument of claim 15 in which:

said housing is cylindrical and includes a forward cavity extending inwardly from said forward end in communication with said switch receiving channel and said detector signal channel; and

said first wedge first outer surface is attached to said piezoelectric switch support surface and extends into said forward cavity.