US 5,441,050 A · Radiation responsive surgical instrument

Abstract

A crystal containing detector particularly suited for use in immunoguided surgery capable of detecting gamma emissions present at tumor sites. The instrument utilizes a cadmium-zinc-telluride detector crystal which may be retained within a finger mount positioned over the surgeon's finger. Within this mount there also is incorporated a first preamplification stage designed to accumulate charge signals from the detector as well as to drive a relatively short length of cable to a second preamplification stage located, for example, within a housing at the surgeon's upper arm. The small finger mounted probe may be moved between operative orientations at the underside of the tip of the finger to stand-by orientations at the top of the finger adjacent the knuckles. In an additional embodiment, the finger probe incorporates a sodium iodide crystal, the scintillations from which are transmitted via a short length of fiber optic cable to an upper arm mounted housing which contains a photomultiplier tube. Signals from the remote, arm-mounted housing then are transmitted via longer cabling or the like to a control console.

Claims22

Dependent claims

A surgical probe instrument for locating and differentiating tissue at which a locator is concentrated, comprising:

a finger mount having a support region and an oppositely disposed finger mount portion configured for slideable positioning and retention upon a portion of a finger of a surgeon, and a detector mount portion positioned at said support region having a crystal retainer comprised of materials attenuating radiation at predetermined energy levels less than about 150 Kev, said detector mount portion having a detector seat and sidewalls extending to a forward opening;
a crystal detector mounted at said detector seat for response to radiation impinging thereon only from said forward opening to provide a detector output;
a window transmissive of said radiation, mounted over said detector mount portion;
transmission means responsive to said detector output for providing a transmit pulsed output;
and
a control system coupled with said transmission means in a manner receiving said pulsed output for validating said transmit pulsed output with respect to said predetermined energy levels to identify valid pulses, said system computing the rate of said valid pulses and generating an audible output audibly perceptible to the surgeon at a frequency selected to correspond with said rate.

3 more elements

An instrument for detecting and locating sources of radiation emission at predetermined energy levels while within a surgical environment, comprising:

a housing having a forward support region;
a crystal retainer assembly supported by said forward support region;
a cadmium-zinc-telluride crystal having forwardly and rearwardly disposed faces, mounted by said crystal retainer assembly and having said Zn component alloyed with Cd and Te components in an amount effective to permit a substantial threshold-based avoidance of electrical noise, and generating a detector output in response to radiation emission;
transmission means for applying electrical ground to said crystal forward face and an electrical bias to said crystal rearward face and including a preamplifier for conveying and treating said detector output to provide a transmitted output, said preamplifier comprising:
a charge accumulating network coupled with said crystal and providing a charge-responsive voltage signal in response to said detector output,
a first voltage amplifier electrically coupled with said charge accumulating network for response to said charge responsive voltage signal to generate a first amplified voltage signal at an output;
a second voltage amplifier stage electrically coupled with said first voltage amplifier stage output for response to said first amplified voltage signal, providing a first bias point value dependent gain selected to produce a second amplified voltage signal, and first temperature responsive solid-state means for effecting a stabilization of said first bias point value under conditions of environmental temperature change;
a third voltage amplifier stage electrically coupled with said second voltage amplifier stage for response to said second amplified voltage signal, providing a second bias point value dependent gain selected to effect a predetermined amplification of said second amplified voltage signal, and second temperature responsive solid-state means for effecting a stabilization of said second bias point value under conditions of environmental temperature change;
and
control means responsive to said transmitted output for providing a perceptible output corresponding therewith.

7 more elements

Apparatus for determining the site of a locator within a patient, comprising:

a housing having a forward support region;
a crystal retainer assembly supported by said forward support region;
a cadmium telluride crystal having forwardly and rearwardly disposed faces mounted by said crystal retainer assembly and generating a detector output in response to radiation emitting at predetermined energy levels from said locator;
a grounding contact electrically coupled with said forwardly disposed surface;
an electrical biasing contact electrically coupled with said rearwardly disposed surface;
a pre-amplifier, including:
a charge accumulating network coupled with said electrical biasing contact and providing a charge-responsive voltage signal in response to said detector output,
a first voltage amplifier stage electrically coupled with said charge accumulating network for response to said charge responsive voltage signal for producing a first amplified voltage signal at an output,
a second voltage amplifier stage electrically coupled with said first voltage amplifier stage output for response to said first amplified voltage signal, providing a first bias point value dependent gain selected to derive a second amplified voltage signal, providing a first bias point value dependent gain selected to produce a second amplified voltage signal, and first temperature responsive solid-state means for effecting a stabilization of said first bias point value under conditions of environmental temperature change, and
a third voltage amplifier stage electrically coupled with said second voltage amplifier stage for response to said second amplified voltage signal, providing a second bias point value dependent gain selected to effect a predetermined amplification of said second amplified voltage signal to generate a third amplified voltage signal, and a second temperature responsive solid-state means for effecting a stabilization of said second bias point value under conditions of environmental temperature change;
and
a control circuit coupled with said third voltage amplifier stage for treating said third amplified voltage signal to generate an emission count based perceptible output.

9 more elements

Dependencies are inferred from the claim text.

Radiation responsive surgical instrument

Life of this patent

Radiation responsive surgical instrument

Life of this patent

Abstract

Claims22