NovaScan

Breast Cancer Detection using Impedance Spectroscopy.

NovaScan Inc. of Milwaukee Wisconsin is currently investigating the efficacy of impedance spectroscopy in the detection of early stage breast cancer. Voith Consulting, LLC has assisted this effort by developing electronic hardware and firmware used in laboratory and clinical devices.

Early work resulted in a proof of concept apparatus shown above (click photo to enlarge). The two central pieces are a water filled tank with electrode plates on both sides and a specially developed 16 channel impedance data acquisition system.

A later unit was developed with 256 platinum electrodes in a 16 x 16 grid suitable for clinical testing on human subjects. An opposing plate (not shown) generates a low voltage signal at varying frequencies between 1 KHz and 1 MHz allowing the impedance spectrum of the intervening tissue to be inferred. The device is battery powered and coupled to a computer via fiber optic cable.

The internal electronic assembly consists of 6 printed circuits in addition to the sensor plate. It is designed so that the first stage trans-resistance amplifier for each sensor is located directly below the sensor and each is laid out identically to limit the sensor to sensor variation as much as possible. The photograph shows the electronic stack powered by a bench power supply. The sensor amplifiers are on the bottom most circuit with multiplexers and phase detectors making up the center 4 boards. The Processor, signal generators and A to D converters are on the top.