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This paper experimentally deals with the measurement of the needle insertion force for breast. The experimental subjects were breast phantom, cow’s breast tissue, and human breast tissue. The needle insertion and force measurement device was used prototype biopsy robot that it was developed by National Cancer Center in Korea. The needle insertion force was measured and compared with various subjects and needle insertion speeds. As a result, the relationship between the needle insertion force and the needle insertion speed for various subjects was identified.

We built and tested a forward-looking polarimetric GPR which measured the scattering matrix of targets. The scattering matrix can be transformed to determine the polarizability angle, relative phase angle, and target magnitude. These quantities are invariant to rotations about the sensor-to-target axis. Measurements were made on dry sand without a target, sand with a buried polystyrene cylinder, and sand with a buried styrofoam cylinder. As frequency was swept the relative phase changed more rapidly when either cylinder was present compared to the sand alone. The relative phase may be a useful feature for detecting plastic objects and voids in sand.

The usefulness of ground penetrating radar to detect landmines has been limited because of low signal-to-clutter ratios which result in high false alarm rates. We describe a method using polarimetric radar to measure the polarizability angle, the relative phase, and the target magnitude. These three independent quantities are directly related to target shape and dimensions and are invariant with respect to rotation about the sensor-to-target axis. We built a forward-looking polarimetric ground penetrating radar and used it to collect data on an automobile disk brake rotor on the surface of dry sand and buried 1 in under the surface of the sand. Measurements were made over a frequency range of 1.35-2.14 GHz. We also performed a computer simulation using the Method of Moments of a target roughly shaped like the rotor. For the simulation and the measured data, the target magnitude exhibited an interference patterns from scattering centers at the edges. The computer simulation revealed that a target has characteristic frequencies marking transitions from reflection being dominated by one polarization state to reflection being dominated by the orthogonal polarization state. For the rotor in uneven ground the characteristic frequencies were found at the maxima of the polarizability angle. At these particular frequencies, the relative phase changes sign. The characteristic frequencies may be useful as a target signature.

The usefulness of ground penetrating radar to detect landmines has been limited because of low signal-to-clutter ratios which result in high false alarm rates. We describe a method using polarimetric radar to measure the polarizability angle, the relative phase, and the target magnitude. These three independent quantities are directly related to target shape and dimensions and are invariant to rotation about the sensor-to-target axis. Data collected on an automobile disk brake rotor over a frequency range of 1.35–2.14 GHz showed that the polarizability angle and the relative phase varied less with frequency when the rotor was buried than when laying on the surface. The target magnitude showed similarities to interference patterns from scattering centers at the edges of a cylinder.

We are studying the effects of electromagnetic fields on the stimulated bioluminescence of dinoflagellates. We use the dinoflagellate Pyrocystis fusiformis which emit a bright flash of blue light when disturbed. We placed a container of P. fusiformis between two electrodes. To stimulate a flash of bioluminescence, a wooden stick was dropped onto the assembly containing the electrodes and dinoflagellate container. Light emerging from the container was captured with a video camera and video images were uploaded to a laptop computer. The electrode voltage was varied between 0, 500, and 1,000 volts AC, corresponded approximately to electric field strengths of 0, 787 and 1,575 V/cm, and the frequency ranged from 5 to 20 kHz. At 4 to 6 hours into the night cycle, we dropped the stick once and then once again five minutes later. For fields of frequency 5 kHz we calculated the ratio of the amount of light emitted during the flash at 5 minutes divided by the light emitted at 0 minutes. There is an interesting trend, as the voltage increased, the ratio decreased. Using a one-factor analysis of variance (ANOVA) we concluded that the application of an electromagnetic field causes a statistically significant decrease in the stimulated bioluminescence of Pyrocystis fusiformis.