Abstract: Methods and apparatus are provided for use in performing electrosurgery, wherein a power supply supplies an electrosurgical instrument with a low voltage power signal having a substantially constant peak-to-peak voltage that is independent of the load impedance and which has a crest factor near unity. A power supply is provided to supply a voltage waveform in accordance with the methods of the invention. A clipping circuit is also provided to permit practice of the methods using conventional electrosurgcial generators and previously known electrosurgical instruments, wherein the voltage amplitude and waveform is modified to the desired regime.

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.

Abstract: A hand-held gamma radiation probe is employed to locate radiation concentrations in animal tissue in conjunction with a control function providing an enhanced audio output particularly suited for cuing the user as to source position. The probe is positioned at a location on the animal body representing background radiation and a squelch low count rate is developed therefrom. The squelch low count rate is multiplied by a range factor to develop a squelch high count rate and frequencies are developed from a look-up frequency table from lowest to highest in correspondence with the developed high and low squelch count rates. Slew rate limiting of the count rates is provided by development of a squelch delta value representing the difference between the squelch high and low count rates divided by a time element. Selection of frequencies for audio output from the frequency table is limited by the value of the squelch delta value.

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 compressively restrained environment employing compliant yet conductive components which also serve to exhibit varying accoustical impedance to impinging microphonic effects. A preamplifier is incorporated within the probe device itself which employs an integrator stage front end combining a field effect transistor and bipolar device with a very small feedback capacitance of less than one picofarad. A bootstrap technique is utilized to enhance the amplification of the bipolar amplification stage. Pulse related signals outputted from the device are normalized and compared to produce pulse data which are analyzed. In one mode of operation a siren effect is employed to guide the surgeon towards emission sources.