Detector and localizer for low energy radiation emissions

• US 5,151,598 A
• Filed: 12/18/1990
• Issued: 09/29/1992
• Est. Priority Date: 03/17/1987
• Status: Expired due to Term

• Current Assignee: Neoprobe Corporation
• Original Assignee: Neoprobe Corporation
• Inventors: Denen, Dennis J.
• Primary Examiner(s): Hannaher, Constantine
• Application Number:
  US07/629,271
• Time in Patent Office: 651 Days
• Field of Search: 128/659, 128/654, 250/370.13, 250/336.1
• US Class Current: 250/336.1
• CPC Class Codes: A61B 6/425 using detectors specially adapted to be used in the interior of the body
• CPC Class Codes: A61B 6/4258 for detecting non x-ray radiation, e.g. gamma radiation A61B6/037 takes precedence
• CPC Class Codes: A61B 6/4423 related to hygiene or sterilisation
• CPC Class Codes: G01T 1/161 Applications in the field of nuclear medicine, e.g. in vivo counting apparatus for radiation diagnosis A61B6/00
• CPC Class Codes: H03F 3/1935 with junction-FET devices

Abstract

A method for fabricating a hand manipular probe suited for use in immuno-guided surgery calling for the detection of very faint gamma emissions for the purpose of localizing cancerous tumor. The probe contains 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. With the method, dead air space is developed between the forward facing window of the probe and the crystal retaining assemblage.

Claims

1. The method of fabricating an instrument for detecting and locating sources of radiation emission having predetermined energy levels, comprising the steps of:

providing a housing having a forwardly disposed portion;

providing a crystal mount formed of material attenuating radiation of said predetermined energy levels and having a forwardly disposed crystal receiving cavity of predetermined depth having a sidewall extending inwardly thereinto to an electrically insulative surface from a forwardly disposed opening;

locating an electrical biasing contact within said cavity upon said insulative surface;

positioning a first electrically conductive compliant member within said cavity and over and in freely-abutting contact with said biasing contact;

providing a radiation responsive crystal having a rearwardly disposed surface and a side portion extending to a forwardly disposed surface;

positioning said rearwardly disposed surface of said radiation responsive crystal within said cavity upon said first electrically conductive compliant member;

positioning a second electrically conductive compliant member over said crystal forwardly disposed surface;

positioning a flexible grounding contact in freely-abutting contact over said second electrically conductive compliant member;

compressing the assemblage of said electrical biasing contact, said first compliant member, said crystal, said second compliant member, and said grounding contact by stretching a resilient retainer thereover;

mounting said compressed assemblage with said crystal mount upon said housing forwardly disposed portion; and

locating a radiation transmissive cap having a forwardly disposed radiation acceptance window over said compressed assemblage and crystal mount in a manner deriving a dead air space between said window and the forwardmost portion of said compressed assemblage.

2. The method of claim 1 including the step of molding a polymeric layer, in situ within said crystal mount receiving cavity with a male mold dimensioned in substantial correspondence with said crystal to provide said electrically insulative surface.

3. The method of claim 1 wherein said crystal mount is provided having a said forwardly disposed crystal receiving cavity wherein said sidewalls are spaced from said crystal side portion a distance selected to effect a substantially non-contacting relationship therebetween.

4. The method of claim 1 wherein said crystal mount is provided having a forwardly disposed crystal receiving cavity formed having said sidewall dimensioned to be spaced from said crystal side portion to define a gap therebetween effective to avoid the generation of electrical noise phenomena by said crystal.

5. The method of claim 4 including the step of molding a polymeric layer, in situ within said crystal mount receiving cavity with a male mold dimensioned in substantial correspondence with said crystal to provide said electrically insulative surface.

6. The method of fabricating an instrument for detecting and locating sources of radiation emission having predetermined energy levels, comprising the steps of:

providing a housing having a forwardly disposed portion;

providing a crystal mount formed of material attenuating radiation of said predetermined energy levels and having a forwardly disposed crystal receiving cavity of predetermined depth having a sidewall extending inwardly thereinto to an inner surface from a forwardly disposed opening;

molding a polymeric layer, in situ within said crystal mount receiving cavity with a male mold dimensioned in substantial correspondence with said crystal to provide an electrically insulative surface;

locating an electrical biasing contact within said cavity upon said insulative surface at said inner surface;

positioning a first electrically conductive compliant member within said cavity and over and in freely-abutting contact with said biasing contact;

providing a radiation responsive crystal having a rearwardly disposed surface and a side portion extending to a forwardly disposed surface;

positioning said reawardly disposed surface of said radiation responsive crystal within said cavity upon said first electrically conductive compliant member;

positioning a second electrically conductive compliant member over said crystal forwardly disposed surface;

positioning a flexible grounding contact in freely-abutting contact over said second electrically conductive compliant member;

compressing the assemblage of said electrical biasing contact, said first compliant member, said crystal, said second compliant member, and said grounding contact by stretching a resilient retainer thereover; and

mounting said compressed assemblage with said crystal mount upon said housing forwardly disposed portion.

7. The method of claim 6 including the step of locating a radiation transmissive cap over said compressed assemblage and crystal mount.

8. The method of fabricating an instrument for detecting and locating sources of radiation emission having predetermined energy levels, comprising the steps of:

providing a housing having a forwardly disposed portion;

providing a crystal mount formed of material attenuating radiation of said predetermined energy levels and having a forwardly disposed crystal receiving cavity of predetermined depth having a sidewall extending inwardly thereinto to an electrically insulative surface from a forwardly disposed opening;

locating an electrical biasing contact within said cavity upon said insulative surface;

positioning a first electrically conductive compliant member within said cavity and over and in freely-abutting contact with said biasing contact;

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

positioning said rearwardly disposed surface of said radiation responsive crystal within said cavity upon said first electrically conductive compliant member;

positioning a second electrically conductive compliant member over said crystal forwardly disposed surface;

positioning a flexible grounding contact in freely-abutting contact over said second electrically conductive compliant member;

compressing the assemblage of said electrical biasing contact, said first compliant member, said crystal, said second compliant member, and said grounding contact by stretching a resilient retainer thereover; and

mounting said compressed assemblage with said crystal mount upon said housing forwardly disposed portion.

9. The method of claim 8 including the step of locating a radiation transmissive cap over said compressed assemblage and crystal mount.

10. The method of claim 8 including the step of molding a polymeric layer, in situ within said crystal mount receiving cavity with a male mold dimensioned in substantial correspondence with said crystal to provide said electrically insulative surface.

11. The method of fabricating an instrument for detecting and locating sources of radiation emission having predetermined energy levels, comprising the steps of:

providing a housing having a forwardly disposed portion;

providing a radiation responsive crystal having a rearwardly disposed surface and a side portion extending to a forwardly disposed surface;

providing a crystal mount formed of material attenuating radiation of said predetermined energy levels and having a forwardly disposed crystal receiving cavity of predetermined depth for receiving said crystal, said cavity having a sidewall extending inwardly thereinto to an electrically insulative surface from a forwardly disposed opening, said cavity sidewall being dimensioned to be spaced from said crystal side portion to define a gap therebetween effective to avoid the generation of noise phenomena by said crystal;

locating an electrical biasing contact within said cavity upon said insulative surface;

positioning a first electrically conductive compliant member within said cavity and over and in freely-abutting contact with said biasing contact;

positioning said rearwardly disposed surface of said radiation responsive crystal within said cavity upon said first electrically conductive compliant member;

positioning a second electrically conductive compliant member over said crystal forwardly disposed surface;

positioning a flexible grounding contact in freely-abutting contact over said second electrically conductive compliant member;

compressing the assemblage of said electrical biasing contact, said first compliant member, said crystal, said second compliant member, and said grounding contact by stretching a resilient retainer thereover; and

mounting said compressed assemblage with said crystal mount upon said housing forwardly disposed portion.

12. The method of claim 11 including the step of locating a radiation transmissive cap over said compressed assemblage and crystal mount.

13. The method of claim 11 including the step of molding a polymeric layer, in situ within said crystal mount receiving cavity with a male mold dimensioned in substantial correspondence with said crystal to provide said electrically insulative surface.