MULTIPLE-ELECTRODE ELECTRICAL IMPEDANCE SENSING BIOPSY SAMPLING DEVICE AND METHOD

摘要

A biopsy sampling device has a trocar with sampling opening, an outer needle with 4 or more electrodes on it, an impedance measuring apparatus coupled to drive current through a first and a second electrode, while measuring voltages through a third and fourth electrodes to measure an impedance of tissue adjacent to the electrodes, the inner trocar within the central cavity of the outer needle such that its sharpened tip and sampling opening can protrude from an end of the outer needle and be removed to capture a sample in the sampling opening. In an embodiment, the electrodes are formed by inking an insulating tubular structure with a conductive ink. In an alternative embodiment, the electrodes are formed by winding conductive metal strips about an insulating tubular structure. In both embodiments, the metal strips or conductive ink is coated with an insulator in a central portion of the sampling device.

主权项

1. A biopsy sampling device comprising:
an inner trocar having a sharpened tip and a sampling opening; an outer needle having a central cavity, the outer needle formed of a material selected from the group consisting of insulators and metal coated with an insulator; at least a first, a second, a third, and a fourth electrical conductor formed on an insulating layer on the outer needle, the conductors forming a first, a second, a third, and a fourth electrode; an insulating coating formed over at least a central portion of the electrical conductors, an impedance measuring apparatus coupled to drive current through a first and a second selected electrode of the electrodes, and measure voltages through a third and fourth selected electrode of the electrodes to measure an impedance of tissue adjacent to the electrodes; an inner trocar slideably engaged within the central cavity of the outer needle such that its sharpened tip and sampling opening may protrude from an end of the outer needle; wherein the inner trocar is adapted to be removed from the outer needle after positioning it with tip and sampling opening protruding from the end of the outer needle and thereby capture a sample in the sampling opening; wherein the impedance measurement apparatus for measuring an alternating current impedance at at least one frequency between one hundred and ten million hertz.