Detector and localizer for low energy radiation emissions

• US 4,893,013 A
• Filed: 09/23/1988
• Issued: 01/09/1990
• Est. Priority Date: 03/17/1987
• Status: Expired due to Fees

• Current Assignee: Neoprobe Corporation Columbus
• Original Assignee: Neoprobe Corporation
• Inventors: Denen, Dennis J., Thurston, Marlin O., Ramsey, Raymond C.
• Primary Examiner(s): Hannaher, Constantine
• Application Number:
  US07/248,920
• Time in Patent Office: 473 Days
• Field of Search: 128/659, 128/654, 250/370.07, 250/370.01, 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 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 a resilient compressible shock cushion layer located at one face of the crystal in conjunction with a biasing surface. Additionally, an elastomeric retainer is positioned over the assemblage of crystal, cup, and shock cushion layer to form a sub-assembly for retention within the device. A dead air space is developed between the forward facing window of the probe and the crystal remaining assemblage.

Claims

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

a housing having interior walls defining an interior cavity and first portion having sidewalls formed of select gamma radiation attenuating material and exhibiting an electrical shielding effect and extending to a forward opening positionable proximate said source, and a hand graspable second portion extending from said first portion;

window means for permitting transmission of gamma radiation of energy level at least as low as 27 kev through said forward opening while blocking the passage of light;

blocking means formed of material selected for attenuating gamma radiation of said predetermined energy levels, having an outer surface, supportable within said housing and having a portion extensible within said housing first portion to a base support surface;

elastomeric means intermediate said housing and said blocking means for retaining said blocking means spaced from said housing interior wall;

electrically insulative support means mounted upon said blocking means base support surface and having a mounting surface positioned outwardly from said base support surface;

a resiliently compressible shock cushion layer positioned in adjacency over said insulative support means and having an outwardly disposed surface;

a gamma radiation responsive crystal having a rearwardly disposed surface positioned in adjacency with said shock cushion layer and having a forwardly disposed surface;

grounding means for electrically grounding said crystal forwardly disposed surface;

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

elastomeric retainer means positioned over the assemblage of said support means, said shock cushion layer, and said crystal for effecting their compressed mutual association;

retaining means for positioning said housing first position over said assemblage and said blocking means portion such that said crystal forwardly disposed surface is spaced from said window means an amount establishing a dead air space therebetween.

2. The instrument of claim 1 in which said elastomeric retainer means is a thin sheath mountable over said assemblage.

3. The instrument of claim 1 in which said resiliently compressible shock cushion layer is a non-woven polytetrafluoraethylene cloth.

4. The instrument of claim 1 in which said elastomeric means is a layer of rubber epoxy adhesive.

5. The instrument of claim 1 including a disposable, sterile, thin polymeric cover positionable over said housing for isolating said housing from contaminants and presenting a sterile instrument exterior for surgery.