Abstract: Induction heating from an induction coil (108) is used to separate a metal medical sharp (144) from its holder (142) by applying a high-frequency oscillating magnetic field that excites eddy currents and resistance heating in the sharp. The heated metal sharp melts the adhesive or plastic securing the sharp to its holder. The use of induction heating is advantageous in that it does not require direct contact between the electrical circuit and the sharp or its holder. The heating can also act to sterilize the sharp and thereby render it less hazardous at the same time that it separates the sharp from its holder. The induction coil can have a stepped or conical shape to concentrate the RF energy at the interface between the metal sharp and its holder.

Abstract: Various disclosed resistivity imaging tools and methods provide a high-resolution electrode configuration for imaging in oil-based imaging in oil-based muds. Some tool embodiments have a sensing surface that comprises: a measurement electrode, a focus electrode surrounding the measurement electrode, and a return electrode surrounding the focus electrode. The sensing surface can be provided on an extendable sensor pad or on the wall-contacting portion of a stabilizer. Some method embodiments include measuring the measurement electrode current while driving a voltage signal between the measurement electrode and the return electrode. The voltage signal may simultaneously or sequentially provide energy at different frequencies. The resistivity measurements are combined with tool position and orientation measurements to form a borehole wall image.

Abstract: Various disclosed resistivity imaging tools and methods provide a high-resolution electrode configuration for imaging in oil-based imaging in oil-based muds. Some tool embodiments have a sensing surface that comprises: a measurement electrode, a focus electrode surrounding the measurement electrode, and a return electrode surrounding the focus electrode. The sensing surface can be provided on an extendable sensor pad or on the wall-contacting portion of a stabilizer. Some method embodiments include measuring the measurement electrode current while driving a voltage signal between the measurement electrode and the return electrode. The voltage signal may simultaneously or sequentially provide energy at different frequencies. The resistivity measurements are combined with tool position and orientation measurements to form a borehole wall image.