Detector and localizer for low energy radiation emissions

• US 5,070,878 A
• Filed: 09/08/1989
• Issued: 12/10/1991
• Est. Priority Date: 11/14/1988
• Status: Expired due to Fees

• Current Assignee: Neoprobe Corporation
• Original Assignee: Neoprobe Corporation
• Inventors: Denen, Dennis J.
• Primary Examiner(s): Howell, Kyle L.
• Assistant Examiner(s): Pfaffle, Krista M.
• Application Number:
  US07/404,403
• Time in Patent Office: 823 Days
• Field of Search: 128/653 R, 128/654, 128/659, 250/370.01, 250/370.07, 250/370.12, 250/370.13, 250/336.1
• US Class Current: 600/436
• 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 detector particularly suited for use in immuno-guided surgery capable of detecting very faint gamma emissions and thereby localizing cancerous tumor. The detector employs a hand manipular probe within which is contained a crystal such as cadmium telluride which is secured in a light-tight environment. A noise immune structuring of the probe and crystal combination includes the utilization of electrically conductive, compliant cushion layer located at one face of the crystal in conjunction with freely abutting biasing and ground contacts. A nylon, resilient retainer is positioned in tension over the assemblage of crystal, ground and biasing contacts and compliant layers to achieve a compressively retained assemblage. A dead air space is developed between the forward facing window of the probe and the crystal retaining assemblage.

Claims

1. An instrument for detecting and locating sources of radiation emission having predetermined energy levels, comprising:

a housing having a forwardly disposed portion;

a crystal mount positioned within said housing forwardly disposed portion, formed of material attenuating radiation of said predetermined energy levels and having a forwardly disposed crystal receiving cavity having sidewalls extending inwardly thereinto from a forwardly disposed opening;

a resilient, electrically insulate polymeric layer within said cavity having an outwardly disposed electrically insulative surface;

a radiation responsive crystal located within said cavity having a rearwardly disposed surface positioned facing said electrically insulative surface and having a side portion extending to a forwardly disposed surface;

biasing means extending within said cavity and having a bias contact adjacent said electrically insulative surface;

a first electrically conductive compliant member conformable with and in contacting adjacency between said crystal rearwardly surface and said bias contact;

a second electrically conductive compliant member conformable with and in contacting adjacency with said crystal forwardly disposed surface;

grounding means positioned in abutting adjacency with said second compliant member for electrically grounding said crystal forwardly disposed surface;

resilient retainer means positioned in tension over said grounding means, said second electrically conductive compliant member and said crystal forwardly disposed surface for compressively retaining components including said grounding means and said second compliant member against said crystal forwardly disposed surface and said rearwardly disposed surface against said first compliant member, and bias contact, and said resilient polymeric layer to an extent effective to provide a stabilization of the electrical contacts to said crystal derived from said basing means and said grounding means and to retain said components in a statically stable state; and

forward cover means positioned over and enclosing said crystal mount crystal receiving cavity, said crystal, said grounding means, and said resilient retainer means for permitting transmission of said radiation emission of said predetermined energy levels.

2. The instrument of claim 1 in which said electrical bias contact is in freely-abutting contact with said first electrically conductive compliant member.

3. The instrument of claim 1 in which said first electrically conductive compliant member is a carbon-filled non-woven polytetrafluoroethylene cloth.

4. The instrument of claim 1 in which said grounding means comprises an electrically conductive member extending over and in freely-abutting contact with said second electrically conductive compliant member.

5. The instrument of claim 1 in which said second electrically conductive compliant member is a carbon-filled, non-woven polytetrafluoroethylene cloth.

6. The instrument of claim 1 including a polymeric, low surface friction coating located over the outwardly disposed surface of said forward cover means.

7. The instrument of claim 1 including a disposable, sterile, thin polymeric cover positionable over said instrument for isolating the components thereof from contaminants and presenting a sterile instrument exterior for surgical utilization.

8. The instrument of claim 1 in which:

said grounding means comprises a wire lead electrically coupled with said housing and extending over and in freely-abutting contact with said second electrically conductive compliant member.

9. The instrument of claim 1 in which said grounding means comprises a wire lead fixed to and supported from said crystal mount and extending over and in freely-abutting contact with said second electrically conductive compliant member.

10. The instrument of claim 1 in which said resilient retainer means is a resilient web positioned in tension over said second electrically conductive compliant member and fixed in tension to said crystal mount.

11. The instrument of claim 1 in which said crystal mount crystal receiving cavity is configured having a depth at least coextensive with said crystal side portion so as to attenuate radiation otherwise incident thereon.

12. The instrument of claim 1 in which:

said bias contact is in freely-abutting contact with said first electrically conductive compliant member;

said grounding means comprises an electrically conductive member extending over and in freely-abutting contact with said second electrically conductive compliant member; and

said resilient retainer means is a resilient web positioned in tension over said grounding means and fixed to said crystal mount so as to effect a compressive retention of said grounding means against said second compliant member and said second compliant member against said crystal forwardly disposed surface.

13. The instrument of claim 12 in which said first and second electrically compliant members are carbon-filled, non-woven polytetrafluoroethylene cloth.

14. The instrument of claim 13 in which said resilient retainer means is a nylon web.

15. An instrument for detecting sources of radiation emissions, comprising:

a housing having a forwardly disposed portion;

a crystal mount positioned within said housing forwardly disposed portion having an electrically insulative forwardly disposed crystal supporting surface;

a radiation responsive crystal having a rearwardly disposed surface positioned facing said crystal mount crystal supporting surface and having a side portion extending to a forwardly disposed surface;

electrical biasing means having a bias contact at said crystal mount crystal supporting surface;

a first electrically conductive compliant cushioning member conformable with and in contacting adjacency between said crystal rearwardly disposed surface and said bias contact;

a second electrically conductive compliant cushioning member conformable with and in contacting adjacency with said crystal forwardly disposed surface;

grounding means positioned in adjacency with said second compliant member for electrically grounding said crystal forwardly disposed surface by electrical association therewith through said second compliant member;

a resilient web retainer positioned in tension over said grounding means and said second electrically conductive compliant cushioning member for compressibly retaining components including said grounding means, said second electrically conductive compliant cushioning member, and said crystal and said first electrically conductive compliant cushioning member upon said crystal mount supporting surface to an extent effective to provide a stabilization of the electrical contacts to said crystal derived from said biasing means and said grounding means and to retain said components in a statically stable state; and

a forward cover positioned over and in enclosing relationship with said crystal mount crystal supporting surface, said crystal, said grounding means, and said first and second electrically conductive compliant cushioning members for excluding external contaminants, and having a forwardly disposed window portion formed of material permitting substantial transmission of said radiation emissions to said crystal forwardly disposed surface, said window portion being spaced forwardly from said crystal to define a dead air space for enhancing the acoustic isolation of said crystal.

16. The instrument of claim 15 in which said crystal mount crystal supporting surface is within a crystal receiving cavity having sidewalls spaced from said crystal side portion to define a gap therebetween of dimension effective to avoid the generation of electrical noise phenomena, said crystal receiving cavity being configured a depth at least coextensive with said crystal side portion so as to attenuate radiation otherwise incident thereon.

17. The instrument of claim 15 in which said electrical biasing means is in freely abutting contact with said first electrically conductive compliant cushioning member.

18. The instrument of claim 15 in which said grounding means comprises an electrically conductive wire member extending over and in freely abutting contact with said second electrically conductive compliant cushioning member.

19. The instrument of claim 15 in which said first electrically conductive compliant cushioning member is a carbon-filled non-woven polytetrafluoroethylene cloth.

20. The instrument of claim 15 in which said second electrically conductive compliant cushioning member is a carbon-filled non-woven polytetrafluoroethylene cloth.

21. The instrument of claim 15 including a disposable, sterile, thin polymeric cover positionable over said instrument for isolating the components thereof from contaminants and presenting a sterile instrument exterior for surgical utilization.

22. The instrument of claim 15 in which said resilient retainer web is fixed in tension to said crystal mount.

23. The instrument of claim 15 in which said resilient retainer is a nylon web.

24. An instrument for detecting sources of gamma radiation emissions, comprising:

a housing having a forwardly disposed portion;

a crystal mount positioned within said housing forwardly disposed portion having an electrically insulative, forwardly disposed crystal supporting surface;

a gamma radiation responsive crystal having a rearwardly disposed surface positioned facing said crystal mount crystal supporting surface and having a side surface extending to a forwardly disposed surface;

compliant cushioning means for locating said cyrstal upon said crystal supporting surface with substantial immunity from externally induced vibration phenomena;

electrical biasing means for applying an electrical bias to said crystal rearwardly disposed surface;

grounding means for electrically grounding said crystal forwardly disposed surface;

a resilient web retainer positioned in tension over and compressively retaining components including said gamma radiation responsive crystal, said compliant cushioning means, said electrical biasing means and said grounding means for effecting the retention thereof in compression upon said crystal mount crystal supporting surface to an extent effective to provide a stabilization of electrical contacts to the crystal derived from said biasing means and said grounding means and to retain said components in a statically stable state; and

a foward cover positioned over and in enclosing relationship with said crystal mount crystal supporting surface, said crystal, said compliant cushioning means, and said grounding means for excluding external contaminants, and having a forwardly disposed window portion formed of material permitting substantial transmission of said gamma radiation to said crystal forwardly disposed surface, said window portion being spaced forwardly from said crystal to define a space enhancing the isolation of said crystal from externally induced vibration phenomena.

25. The instrument of claim 24 in which:

said compliant cushioning means is electrically conductive; and

said grounding means is configured to assert ground to said crystal forwardly disposed surface through said compliant cushioning means.

26. The instrument of claim 24 in which:

said compliant cushioning means is electrically conductive; and

said electrical biasing means is configured to apply said electrical bias to said crystal rearwardly disposed surface through said compliant cushioning means.

27. The instrument of claim 24 including a disposable, sterile, thin polymeric cover positionable over said instrument for isolating the components thereof from contaminants and presenting a sterile instrument exterior for surgical utilization.

28. The instrument of claim 24 in which said resilient retainer means is a nylon web.

29. The instrument of claim 24 in which said compliant cushioning means is a carbon-filled, non-woven polytetrafluoroethylene cloth.

30. An instrument for detecting and locating sources of radiation emission having predetermined energy levels, comprising:

a housing having a forwardly disposed portion;

a crystal mount positioned within said housing forwardly disposed portion, formed of material attenuating radiation of said predetermined energy levels and having a forwardly disposed crystal receiving cavity having a sidewall extending inwardly thereinto to an electrically insulative surface from a forwardly disposed opening.

a radiation responsive crystal located within said cavity having a rearwardly disposed surface positioned facing said electrically insulative surface and having a side portion extending to a forwardly disposed surface, said crystal side portion being spaced from said crystal receiving cavity sidewall a distance selected to effect a substantially non-contacting relationship therebetween;

biasing means extending within said cavity and having a bias contact adjacent said electrically insulative surface;

a first electrically conductive compliant member conformable with and in contacting adjacency between said crystal rearwardly disposed surface and said bias contact;

a second electrically conductive compliant member conformable with and in contacting adjacency with said crystal forwardly disposed surface;

grounding means positioned in abutting adjacency with said second compliant member for electrically ground said crystal forwardly disposed surface;

resilient retainer means positioned in tension over said grounding means, said second electrically conductive compliant member and said crystal forwardly disposed surface for compressively retaining said grounding means and said second compliant member against said crystal forwardly disposed surface and said rearwardly disposed surface against said first compliant member and said bias contact; and

forward cover means positioned over and enclosing said crystal mount, said crystal, said grounding means, and said resilient means for permitting transmission of said radiation emission of said predetermined energy levels.

31. The instrument of claim 30 in which said radiation responsive crystal side portion is spaced from said crystal receiving cavity sidewall a distance of about 0.005 inch.

32. The instrument of claim 30 including a disposable, sterile, thin polymeric cover positionable over said instrument for isolating the components thereof from contaminants and presenting a sterile instrument exterior for surgical utilization.

33. An instrument for detecting and locating sources of radiation emission having predetermined energy levels, comprising:

a housing having a forwardly disposed portion;

a crystal mount positioned within said housing forwardly disposed portion, formed of material attenuating radiation of said predetermined energy levels and having a forwardly disposed crystal receiving cavity having a sidewall extending thereinto to an electrically insulative surface from a forwardly disposed opening;

a radiation responsive crystal located within said cavity having a rearwardly disposed surface positioned facing said electrically insulative surface and having a side portion extending to a forwardly disposed surface, said crystal side portion being spaced from said crystal receiving cavity sidewall to define a gap therebetween effective to avoid the generation of electrical noise phenomena;

biasing means extending within said cavity and having a bias contact adjacent said electrically insulative surface;

a first electrically conductive compliant member conformable with and in contacting adjacency between said crystal rearwardly disposed surface and said bias contact;

a second electrically conductive compliant member conformable with and in contacting adjacency with said crystal forwardly disposed surface;

grounding means positioned in abutting adjacency with said second compliant member for electrically grounding said crystal forwardly disposed surface;

resilient retainer means positioned in tension over said grounding means, said second electrically conductive compliant member and said crystal forwardly disposed surface for compressively retaining said grounding means and said second compliant member against said crystal forwardly disposed surface and said rearwardly disposed surface against said first compliant member and said bias contact; and

forward cover means positioned over and enclosing said crystal mount, said crystal, said grounding means, and said resilient retainer means for permitting transmission of said radiation emissions of said predetermined energy levels.

34. An instrument for detecting sources of radiation emissions, comprising:

a housing having a forwardly disposed portion;

a crystal mount positioned within said housing forwardly disposed portion having a crystal receiving cavity with a sidewall extending inwardly thereinto to an electrically insulative forwardly disposed crystal supporting surface;

a radiation responsive crystal having a rearwardly disposed surface positioned facing said crystal mount crystal supporting surface and having a side portion extending to a forwardly disposed surface, said crystal side portion being spaced from said crystal receiving cavity sidewall to define a gap therebetween of dimension effective to avoid generation of noise phenomena;

electrical biasing means having a bias contact at said crystal mount crystal supporting surface;

a first electrically conductive compliant cushioning member conformable with and in contacting adjacency between said crystal rearwardly disposed surface and said bias contact; and

a second electrically conductive compliant cushioning member conformable with and in contacting adjacency between said crystal forwardly disposed surface;

grounding means positioned in adjacency with said second compliant member for electrically grounding said crystal forwardly disposed surface;

resilient retainer means positioned in tension over said second electrically conductive compliant cushioning member for compressibly retaining said second electrically conductive compliant cushioning member, said crystal and said first electrically conductive compliant cushioning member upon said crystal mount supporting surface; and

a forward cover positioned over and in enclosing relationship with said crystal mount crystal supporting surface, said crystal, and said first and second electrically compliant cushioning members for excluding external contaminants, and having a forwardly disposed window portion formed of material permitting substantial transmission of said radiation emissions to said crystal forwardly disposed surface, said window portion being spaced forwardly from said crystal to define a dead air space for enhancing the acoustic isolation of said crystal.

35. An instrument for detecting sources of gamma radiation emissions, comprising:

a housing having a forwardly disposed portion;

a crystal mount positioned within said housing forwardly disposed portion having a crystal receiving cavity with a sidewall extending inwardly thereinto to an electrically insulative, forwardly disposed crystal supporting surface.

a gamma radiation responsive crystal having a rearwardly disposed surface positioned facing said crystal mount crystal supporting surface and having a side surface extending to a forwardly disposed surface, said crystal side surfaces being spaced from said crystal receiving cavity sidewall to define a gap therebetween of dimension effective to avoid the generation of noise phenomena;

compliant cushioning means for locating said crystal upon said crystal supporting surface with substantial immunity from externally induced vibration phenomena;

electrical biasing means for applying an electrical bias to said crystal rearwardly disposed surface;

grounding means for electrically grounding said crystal forwardly disposed surface;

resilient retainer means positioned in tension over said gamma radiation responsive crystal, said compliant cushioning means, said electrical biasing means and said grounding means for effecting the retention thereof in compression upon said crystal mount crystal supporting surface; and

a forward cover positioned over and in enclosing relationship with said crystal mount crystal supporting surface, said crystal, said compliant cushioning means, and said grounding means for excluding external contaminants, and having a forwardly disposed window portion formed of material permitting substantial transmission of said gamma radiation to said crystal forwardly disposed surface, said window portion being spaced forwardly from said crystal to define a space enhancing the isolation of said crystal from externally induced vibration phenomena.

36. An instrument for detecting and locating sources of radiation emission having predetermined energy levels, comprising:

a housing having a forwardly disposed portion;

a crystal mount positioned within said housing forwardly disposed portion, formed of material attenuating radiation of said predetermined energy levels and having a forwardly disposed crystal receiving cavity having a sidewall extending inwardly thereinto to an electrically insulative surface from a forwardly disposed opening.

a radiation responsive crystal located within said cavity having a rearwardly disposed surface positioned facing said electrically insulative surface and having a side portion extending to a forwardly disposed surface, said crystal side portion being spaced from said crystal receiving cavity sidewall a distance of about 0.005 inch;

biasing means extending within said cavity and having a bias contact adjacent said electrically insulative surface;

a first electrically conductive compliant member conformable with and in contacting adjacency between said crystal rearwardly disposed surface and said bais contact;

a second electrically conductive compliant member conformable with and in contacting adjacency with said crystal forwardly disposed surface;

grounding means positioned in abutting adjacency with said second compliant member for electrically grounding said crystal forwardly disposed surface;

resilient retainer means positioned in tension over said grounding means, said second electrically conductive compliant member and said crystal forwardly disposed surface for compressively retaining said grounding means and said second compliant member against said crystal forwardly disposed surface and said rearwardly disposed surface against said first compliant member and said bais contact; and

forward cover means positioned over and enclosing said crystal mount, said crystal, said grounding means, and said resilient retainer means for permitting transmission of said radiation emission of said predetermined energy levels.

37. An instrument for detecting and locating sources of radiation emission having predetermined energy levels comprising:

a housing having a forwardly disposed portion;

a crystal mount positioned within said housing forwardly disposed portion, formed of material attenuating radiation of said predetermined energy levels and having a forwardly disposed crystal receiving cavity having sidewalls extending inwardly thereinto from a forwardly disposed opening;

a pliant, electrically insulative and cushioning polymeric layer within said cavity having an outwardly disposed electrically insulative surface;

a radiation responsive crystal located within said cavity having a rearwardly disposed surface positioned facing said electrically insulative surface and having a side portion extending to a forwardly disposed surface;

biasing means extending within said cavity and having a bias contact adjacent said electrically insulative surface;

a first electrically conductive compliant member conformable with and in contacting adjacency between said crystal rearwardly disposed surface and said bais contact;

a second electrically conductive compliant member conformable with and in contacting adjacency with said crystal forwardly disposed surface;

at least one thin grounding wire electrically coupled with said housing and extending over and in freely-abutting contact with said second electrically conductive compliant member.

a resilient retainer web positioned in tension over said grounding means, said second electrically conductive compliant member and said crystal forwardly disposed surface for compressively retaining components including said grounding wire and said second compliant member against said crystal forwardly disposed surface and said rearwardly disposed surface against said first compliant member, said bais contact, and said resilient polymeric layer to an extent effective to provide a stabilization of the electrical contacts to said crystal derived from said biasing means and said grounding means and to retain said components in a statically stable state; and

forward cover means positioned over and enclosing said cyrstal mount crystal receiving cavity, said crystal, said grounding wire and said resilient retainer web for permitting transmission of said radiation emission of said predetermined energy levels.

38. An instrument for detecting sources of gamma radiation emissions, comprising:

a housing having a forwardly disposed portion;

a crystal mount positioned within said housing forwardly disposed portion having an electrically insulative, forwardly disposed crystal supporting surface;

a gamma radiation responsive crystal having a rearwardly disposed surface positioned facing said crystal mount crystal supporting surface and having a side surface extending to a forwardly disposed surface;

compliant cushioning means for locating said crystal upon said crystal supporting surface with substantially immunity from externally induced vibration phenomena;

electrical biasing means for applying an electrical bias to said crystal rearwardly disposed surface;

a resilient nylon web retainer positioned in tension over and compressively retaining components including said gamma radiation responsive crystal, said compliant cushioning means, said electrical biasing means and said grounding means for effecting the retention thereof in compression upon said crystal mount crystal supporting surface to an extent effective to provide a stabilization of electrical contacts to the crystal derived from said biasing means and said grounding means and to retain said components in a statically stable state; and

a forward cover positioned over and in enclosing relationship with said crystal mount crystal supporting surface, said crystal, said compliant cushioning means, and said grounding means for excluding external contaminants, and having a forwardly disposed window portion formed of material permitting substantial transmission of said gamma radiation to said crystal forwardly disposed surface, said window portion being spaced forwardly from said crystal to define a space enhancing the isolation of said crystal from externally induced vibration phenomena.

39. An instrument for detecting sources of radiation emissions, comprising:

a housing having a forwardly disposed portion;

a crystal mount positioned within said housing forwardly disposed portion having an electrically insulative forwardly disposed crystal supporting surface;

a radiation responsive crystal having a rearwardly disposed surface positioned facing said crystal mount supporting surface and having a side portion extending to a forwardly disposed surface;

electrical biasing means having a bias contact at said crystal mount supporting surface;

a first electrically conductive compliant cushioning member conformable with and in contacting adjacency between said crystal rearwardly disposed surface and said bias contact;

a second electrically conductive compliant cushioning member conformable with and in contacting adjacency with said crystal forwardly disposed surface;

a plurality of thin grounding wires positioned in adjacency with said second compliant member for electrically grounding said crystal forwardly disposed surface by electrical association therewith through said second compliant member.

a resilient web retainer positioned in tension over said grounding wires and said second electrically conductive compliant cushioning member for compressibly retaining components including said grounding wires, said second electrically conductive compliant cushioning member, and said crystal and said first electrically conductive compliant cushioning member upon said crystal mount supporting surface to an extent effective to provide a stabilization of the electrical contacts to said crystal derived from said biasing means and said grounding wires and to retain said components in a statically stable state; and

a forward cover positioned over and in enclosing relationship with said crystal mount crystal supporting surface, said crystal, said grounding wires, and said first and second electrically conductive compliant cushioning members for excluding external contaminants, and having a forwardly disposed window portion formed of material permitting substantial transmission of said radiation emissions to said crystal forwardly disposed surface, said window portion being spaced forwardly from said crystal to define a dead air space for enhancing the acoustic isolation of said crystal.

40. An instrument for detecting and locating sources of radiation emission having predetermined energy levels, comprising:

a housing having a forwardly disposed portion;

a crystal mount positioned within said housing forwardly disposed portion, formed of material attenuating radiation of said predetermined energy levels and having a forwardly disposed crystal receiving cavity having sidewalls extending inwardly thereinto from a forwardly disposed opening;

a resilient, electrically insulative and cushioning polymeric layer within said cavity having an outwardly disposed electrically insulative surface;

a radiation responsive crystal located within said cavity having a rearwardly disposed surface positioned facing said electrically insulative surface and having a side portion extending to a forwardly disposed surface;

biasing means extending within said cavity and having a bias contact adjacent said electrically insulative surface;

a first electrically conductive compliant member formed of carbon-filled, non-woven polytetrafluoroethylene cloth conformable with and in contacting adjacency between said crystal rearwardly disposed surface and said bias contact;

a second electrically conductive compliant member formed of carbon-filled, non-wove polytetrafluoroethylene cloth conformable with and in contacting adjacency with said crystal forwardly disposed surface;

grounding means positioned in abutting adjacency over said second compliant member for electrically grounding said crystal forwardly disposed surface;

resilient retainer means positioned in tension over said grounding means, said second electrically conductive compliant member and said crystal forwardly disposed surface for compressively retaining components including said grounding means and said second compliant member against said crystal forwardly disposed surface and said rearwardly disposed surface against said first compliant member, said bias contact, and said resilient polymeric layer to an extent effective to provide a stabilization of the electrical contacts to said crystal derived from said biasing means and said grounding means and to retain said components in a statically stable state; and

forward cover means positioned over and enclosing said crystal mount crystal receiving cavity, said crystal, said grounding means, and said resilient retainer means for permitting transmission of said radiation emission of said predetermined energy levels.