Patent Description:
The present invention relates to biopsy devices, and, more particularly, to a biopsy device having a probe for measuring tissue impedance.

A biopsy may be performed on a patient to help in determining whether the tissue in a region of interest includes cancerous cells. One biopsy technique involves inserting a biopsy probe into the tissue region of interest to capture one or more tissue samples from the region. Such a biopsy technique often utilizes a sharp probe to penetrate tissue adjacent to, or in, the tissue region of interest, after which a tissue sample is collected. Efforts continue in the art to improve the ability of the biopsy device to monitor the tissue penetration aspects of collecting a tissue sample.

What is needed in the art is a biopsy apparatus having a biopsy probe for measuring tissue impedance, to facilitate tissue type determination and/or penetration depth measurements. <CIT> discloses a biopsy sampling device having a trocar with sampling opening, an outer needle with four or more electrodes on it, an impedance measuring apparatus coupled to drive current through a first and second electrode, while measuring voltages through a third and fourth electrodes to measure an impedance of tissue adjacent to the electrodes, the inner trocar with 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 sample opening. This publication shows a device as defined in the preamble of claim <NUM>.

The present invention provides a biopsy apparatus having a biopsy probe for measuring tissue impedance to facilitate tissue type determination and/or penetration depth measurements. The present invention is directed to the impedance measuring probe for use in a biopsy apparatus according to claim <NUM>. The dependent claims refer to preferred embodiments.

The invention, according to claim <NUM>, is directed to an impedance measuring probe for use in a biopsy apparatus. The impedance measuring probe includes a metal elongate member having a longitudinal axis, an elongate surface, a proximal end, a distal end, a proximal end portion that extends distally from the proximal end, and a distal end portion that extends proximally from the distal end. The elongate surface has a recessed longitudinal channel having a radial depth that longitudinally extends from the proximal end portion into the distal end portion. A plurality of conductive wire electrodes (<NUM>), each conductive wire electrode of the plurality of conductive wire electrodes having a connection end (<NUM>-<NUM>) and a sensing end (<NUM>-<NUM>), each conductive wire electrode (<NUM>) of the plurality of conductive wire electrodes located in and extends along the recessed longitudinal channel (<NUM>-<NUM>), the connection end (<NUM>-<NUM>) extending from the proximal end portion (<NUM>-<NUM>) of the metal elongate member (<NUM>) and the sensing end (<NUM>-<NUM>) being located at the distal end portion (<NUM>-<NUM>) of the metal elongate member (<NUM>); and an insulation material (<NUM>) disposed in the recessed longitudinal channel (<NUM>-<NUM>) of the metal elongate member (<NUM>) and around the conductive wire electrodes (<NUM>) so as to electrically insulate the conductive wire electrodes (<NUM>), and with the sensing end (<NUM>-<NUM>) of the conductive wire electrode (<NUM>) being exposed at the distal end portion (<NUM>-<NUM>) of the metal elongate member (<NUM>).

The disclosure is directed to a biopsy apparatus. The biopsy apparatus includes a biopsy driver having a housing that carries a controller circuit and a motor. The controller circuit is electrically and communicatively coupled to the motor. The motor has a motor shaft. An elongate metal stylet has an elongate surface, a proximal end, a distal end, a proximal end portion that extends distally from the proximal end, and a distal end portion that extends proximally from the distal end. The proximal end portion is drivably coupled to the motor shaft of the motor. The elongate surface has a plurality of recessed longitudinal channels that extends from the proximal end portion and into the distal end portion. Each recessed longitudinal channel of the plurality of recessed longitudinal channels has a radial depth. At least one conductive wire electrode is positioned in each channel of the plurality of recessed longitudinal channels, wherein each conductive wire electrode is located in and extends along a respective recessed longitudinal channel of the plurality of recessed longitudinal channels. Each conductive wire electrode has a connection end that extends from the proximal end portion of the elongate metal stylet and has a sensing end that is located in the distal end portion of the elongate metal stylet. The connection end is electrically connected to the controller circuit. Insulation material is disposed in the plurality of recessed longitudinal channels of the elongate metal stylet and around each respective conductive wire electrode so as to electrically insulate each respective conductive wire electrode. The sensing end of each respective conductive wire electrode is exposed at the distal end portion of the elongate metal stylet.

The disclosure, in another form not citing all features of claim <NUM>, is directed to an impedance measuring probe arrangement for use with a biopsy apparatus. The impedance measuring probe includes a tubular member having a tubular side wall that has a first proximal end, a first distal end, and a first distal end portion that extends proximally from the first distal end. The tubular side wall defines a lumen. An elongate metal stylet is positioned in the lumen. The elongate metal stylet has a second proximal end, a second distal end and a second distal end portion that extends proximally from the second distal end. At least one recessed longitudinal channel is formed in one of, or both of, the tubular side wall of the tubular member and the elongate metal stylet, wherein each recessed longitudinal channel extends along a longitudinal extent of one of the tubular side wall of the tubular member and the elongate metal stylet. At least one conductive wire electrode is positioned in each recessed longitudinal channel. The conductive wire electrode is electrically insulated from the tubular member and the elongate metal stylet by insulation material. Each conductive wire electrode has a connection end and a sensing end.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

Referring now to the drawings, and more particularly to <FIG>, there is shown a biopsy apparatus <NUM> which generally includes a biopsy driver <NUM> and a probe arrangement <NUM>. In the present embodiment, probe arrangement <NUM> may include an elongate stylet <NUM> and an elongate coaxial cannula <NUM>. In some applications, however, elongate stylet <NUM> may be used without coaxial cannula <NUM>. In accordance with an aspect of the present invention, at least one component of probe arrangement <NUM> (e.g., the stylet, the cannula, or both the stylet and the cannula) may be configured to serve as an impedance measuring probe.

Referring also to <FIG>, biopsy driver <NUM> has a housing <NUM> that carries, e.g., contains, a user interface <NUM>, a controller circuit <NUM>, and a motor <NUM>. Controller circuit <NUM> is electrically and communicatively coupled to each of user interface <NUM> and motor <NUM>, e.g., by wires and/or circuit traces. User interface <NUM> may be, for example, a touch input LCD display screen. Motor <NUM> may be, for example, a direct current (DC) motor having a motor shaft <NUM>-<NUM> that is drivably coupled to elongate stylet <NUM> to rotate elongate stylet <NUM>. Controller circuit <NUM> is configured to be electrically and communicatively coupled to the impedance measuring probe, e.g., at least one component of probe arrangement <NUM>, as more fully described below.

As shown in <FIG>, controller circuit <NUM> includes a processor circuit <NUM>, an analog-to-digital (A/D) converter circuit <NUM>, and a pulse width modulation (PWM) circuit <NUM>. Processor circuit <NUM> is electrically and communicatively coupled to A/D converter circuit <NUM>, PWM circuit <NUM>, and user interface <NUM>, e.g., by wires and/or circuit traces. Controller circuit <NUM> may be formed as one or more Application Specific Integrated Circuits (ASIC).

A/D converter circuit <NUM> includes multiple impedance input ports <NUM>, which are grouped into two subsets, namely: impedance input ports ZIN-A, ZIN-B. ZIN-X and impedance input ports ZIN-<NUM>, ZIN-<NUM>. Impedance input ports ZIN-A, ZIN-B. ZIN-X may be used, for example, to receive impedance inputs for tissue impedance/composition determinations. Impedance input ports ZIN-<NUM>, ZIN-<NUM>. ZIN-N may be used, for example, to receive impedance inputs for probe penetration depth determinations. Respective connection ends from the impedance measuring probe (e.g., at least one component of probe arrangement <NUM>) are connected to the impedance input ports, either directly or via a resistive voltage divider arrangement.

Processor circuit <NUM> includes, for example, a microprocessor <NUM>-<NUM>, a non-transitory electronic memory circuit <NUM>-<NUM>, and associated circuitry, such as an input/output interface, clock, buffers, etc. Memory circuit <NUM>-<NUM> is a non-transitory electronic memory that may include volatile memory, such as random access memory (RAM), and nonvolatile memory, such as read only memory (ROM), electronically erasable programmable ROM (EEPROM), NOR flash memory, NAND flash memory, etc..

Processor circuit <NUM> is configured via software and/or firmware residing in memory circuit <NUM>-<NUM> to execute program instructions to perform functions associated with reading the impedance at each of the multiple impedance input ports <NUM> of A/D converter circuit <NUM>, and processing the various impedance inputs to generate user data, such as tissue type, to be displayed at user interface <NUM>, and to generate motor control signals, which are supplied to PWM circuit <NUM>. PWM circuit <NUM> converts the motor control signals supplied by processor circuit <NUM> into PWM signals which are supplied to motor <NUM> for controlling the revolutions-per-minute (RPMs) of motor shaft <NUM>-<NUM> of motor <NUM>.

In the embodiment depicted in <FIG>, elongate stylet <NUM> is configured as an impedance measuring probe and coaxial cannula <NUM> is a passive guide component.

Referring particularly to <FIG>, coaxial cannula <NUM> includes an elongate tubular member (cannula) <NUM> and a hub <NUM>. The elongate tubular member <NUM> has a tubular side wall <NUM>, and may be formed from metal, such as stainless steel. Hub <NUM> may be formed from plastic, such as a rigid polymer. Tubular side wall <NUM> has a proximal end <NUM>-<NUM>, a distal end <NUM>-<NUM>, a proximal end portion <NUM>-<NUM>, and a lumen <NUM>-<NUM>. Proximal end portion <NUM>-<NUM> extends distally from proximal end <NUM>-<NUM>. Hub <NUM> is fixedly attached, e.g., by adhesive, to proximal end portion <NUM>-<NUM> of tubular side wall <NUM>. Hub <NUM> may serve as a user handhold and as a mounting feature for attachment to housing <NUM> of biopsy driver <NUM>. Lumen <NUM>-<NUM> is sized to slidably receive elongate stylet <NUM>. As shown in <FIG>, elongate stylet <NUM> may be removably positioned in lumen <NUM>-<NUM>.

Referring particularly to <FIG>, in the present embodiment, elongate stylet <NUM> is a solid elongate member made of metal, e.g., stainless steel, having a longitudinal axis <NUM>-<NUM>, a proximal end <NUM>-<NUM>, a distal end <NUM>-<NUM>, a proximal end portion <NUM>-<NUM> that extends distally from proximal end <NUM>-<NUM>, e.g., a distance of one to three centimeters (cm), and a distal end portion <NUM>-<NUM> that extends proximally from distal end <NUM>-<NUM>, e.g., a distance of one to five centimeters (cm). Distal end portion <NUM>-<NUM> includes a tapered tip portion <NUM>-<NUM>, and distal end <NUM>-<NUM> is a sharp tip of the tapered tip portion <NUM>-<NUM> which is used to create a hole in tissue, e.g., dense tissue, such as bone. Elongate stylet <NUM> also includes an outer elongate surface <NUM>. Proximal end portion <NUM>-<NUM> is configured to be drivably coupled to motor shaft <NUM>-<NUM> of motor <NUM> (see also <FIG>).

In accordance with an aspect of the present invention, outer elongate surface <NUM> has at least one longitudinal channel <NUM>-<NUM>, and in the present embodiment, outer elongate surface <NUM> has a plurality of recessed longitudinal channels <NUM>, individually identified as longitudinal channel <NUM>-<NUM>, longitudinal channel <NUM>-<NUM>, longitudinal channel <NUM>-<NUM>, and longitudinal channel <NUM>-<NUM>. Each of the plurality of recessed longitudinal channels <NUM> extends from proximal end portion <NUM>-<NUM> and into distal end portion <NUM>-<NUM>, and with each recessed longitudinal channel <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> having a radial depth, i.e., a depth in the direction toward longitudinal axis <NUM>-<NUM> that extends along the lengthwise extent of elongate stylet <NUM>. The plurality of recessed longitudinal channels <NUM> may be formed, for example, by cutting the surface, or formed during a casting/molding process.

A plurality of conductive wire electrodes <NUM> is located in and extends along the plurality of recessed longitudinal channels <NUM>. In the present example, each recessed longitudinal channel <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> receives a respective conductive wire electrode <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>. However, it is contemplated that in some implementations one or more of the plurality of recessed longitudinal channels <NUM> may carry multiple conductive wire electrodes. Conductive wire electrode <NUM>-<NUM> has a lengthwise extent between a connection end <NUM>-<NUM> and a sensing end <NUM>-<NUM>. Conductive wire electrode <NUM>-<NUM> has a lengthwise extent between a connection end <NUM>-<NUM> and a sensing end <NUM>-<NUM>. Conductive wire electrode <NUM>-<NUM> has a lengthwise extent between a connection end <NUM>-<NUM> and a sensing end <NUM>-<NUM>. Conductive wire electrode <NUM>-<NUM> has a lengthwise extent between a connection end <NUM>-<NUM> and a sensing end <NUM>-<NUM>.

Each of connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, and connection end <NUM>-<NUM> extends from proximal end portion <NUM>-<NUM> of elongate stylet <NUM>, and each is respectively electrically and communicatively coupled to one of the multiple impedance input ports <NUM> of A/D converter circuit <NUM> of controller circuit <NUM>, e.g., one of impedance input ports ZIN-A, ZIN-B. ZIN-X and/or impedance input ports ZIN-<NUM>, ZIN-<NUM>. ZIN-N (see also <FIG>). Each of sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, and sensing end <NUM>-<NUM> is located at distal end portion <NUM>-<NUM> of elongate stylet <NUM>. In the present embodiment, sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, and sensing end <NUM>-<NUM> are located at distal end portion <NUM>-<NUM> of elongate stylet <NUM>, and are positioned in a circumferential arrangement at the distal end portion <NUM>-<NUM> of elongate stylet <NUM> near the distal tip at distal end <NUM>-<NUM> of elongate stylet <NUM>, with the circumferential arrangement configured to provide tissue impedance information.

An insulation material <NUM>, such as a non-conductive polymer, e.g., silicone rubber, is disposed in each recessed longitudinal channel <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> and around the respective conductive wire electrode <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> so as to electrically insulate the respective conductive wire electrode <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> from elongate stylet <NUM>, and from coaxial cannula <NUM> when elongate stylet <NUM> is inserted into coaxial cannula <NUM>. Insulation material <NUM> encapsulates a lengthwise portion of the conductive wire electrode between the connection end and the sensing end, with the respective ends being free of insulation material to allow electrical contact or connection.

In the present embodiment, insulation material <NUM> fills each recessed longitudinal channel of the plurality of recessed longitudinal channels <NUM>. The distal extent of insulation material <NUM> terminates prior to covering sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, and sensing end <NUM>-<NUM> of the plurality of conductive wire electrodes <NUM>, such that sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, and sensing end <NUM>-<NUM> are exposed at distal end portion <NUM>-<NUM> of elongate stylet <NUM>. Likewise, the proximal extent of insulation material <NUM> terminates prior to covering connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, and connection end <NUM>-<NUM> of the plurality of conductive wire electrodes <NUM>, such that connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, and connection end <NUM>-<NUM> are exposed and available for connection to A/D converter circuit <NUM> of controller circuit <NUM>.

<FIG> shows an alternative elongate stylet <NUM> configured as an impedance measuring probe, which may be substituted for elongate stylet <NUM> of probe arrangement <NUM>. Elongate stylet <NUM> may be in the form of a solid elongate member made from metal, e.g., stainless steel, having a longitudinal axis <NUM>-<NUM>, a proximal end <NUM>-<NUM>, a distal end <NUM>-<NUM>, a proximal end portion <NUM>-<NUM> that extends distally from proximal end <NUM>-<NUM>, e.g., a distance of one to three centimeters (cm), and a distal end portion <NUM>-<NUM> that extends proximally from distal end <NUM>-<NUM>, e.g., a distance of one to five centimeters (cm). Elongate stylet <NUM> also includes an outer elongate surface <NUM>. Proximal end portion <NUM>-<NUM> is configured to be drivably coupled to motor shaft <NUM>-<NUM> of motor <NUM> (see also <FIG>). Distal end portion <NUM>-<NUM> includes a tapered tip portion <NUM>-<NUM>, and distal end <NUM>-<NUM> is a sharp tip of the tapered tip portion <NUM>-<NUM> which is used to create a hole in tissue, e.g., dense tissue, such as bone.

In accordance with an aspect of the present invention, elongate surface <NUM> has a plurality of recessed longitudinal channels <NUM>, individually identified as longitudinal channel <NUM>-<NUM>, longitudinal channel <NUM>-<NUM>, longitudinal channel <NUM>-<NUM>, and longitudinal channel <NUM>-<NUM>. Each of the plurality of recessed longitudinal channels <NUM> extends from proximal end portion <NUM>-<NUM> and into distal end portion <NUM>-<NUM>, and with each recessed longitudinal channel <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> having a radial depth, i.e., a depth in a direction toward longitudinal axis <NUM>-<NUM> that extends along the lengthwise extent of elongate stylet <NUM>.

A plurality of conductive wire electrodes <NUM> is located in and extends along the plurality of recessed longitudinal channels <NUM>. In the present example, recessed longitudinal channel <NUM>-<NUM> receives conductive wire electrodes <NUM>-<NUM>, <NUM>-<NUM>; recessed longitudinal channel <NUM>-<NUM> receives conductive wire electrodes, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>; recessed longitudinal channel <NUM>-<NUM> receives conductive wire electrode <NUM>-<NUM>; and, recessed longitudinal channel <NUM>-<NUM> receives conductive wire electrode <NUM>-<NUM>.

Conductive wire electrode <NUM>-<NUM> has a lengthwise extent between a connection end <NUM>-<NUM> and a sensing end <NUM>-<NUM>. Conductive wire electrode <NUM>-<NUM> has a lengthwise extent between a connection end <NUM>-<NUM> and a sensing end <NUM>-<NUM>. Conductive wire electrode <NUM>-<NUM> has a lengthwise extent between a connection end <NUM>-<NUM> and a sensing end <NUM>-<NUM>. Conductive wire electrode <NUM>-<NUM> has a lengthwise extent between a connection end <NUM>-<NUM> and a sensing end <NUM>-<NUM>. Conductive wire electrode <NUM>-<NUM> has a lengthwise extent between a connection end <NUM>-<NUM> and a sensing end <NUM>-<NUM>. Conductive wire electrode <NUM>-<NUM> has a lengthwise extent between a connection end <NUM>-<NUM> and a sensing end <NUM>-<NUM>. Conductive wire electrode <NUM>-<NUM> has a lengthwise extent between a connection end <NUM>-<NUM> and a sensing end <NUM>-<NUM>. Conductive wire electrode <NUM>-<NUM> has a lengthwise extent between a connection end <NUM>-<NUM> and a sensing end <NUM>-<NUM>. Conductive wire electrode <NUM>-<NUM> has a lengthwise extent between a connection end <NUM>-<NUM> and a sensing end <NUM>-<NUM>.

Each of connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, and connection end <NUM>-<NUM> extends from proximal end portion <NUM>-<NUM> of elongate stylet <NUM>, and each is respectively electrically and communicatively coupled to one of the multiple impedance input ports <NUM> of A/D converter circuit <NUM> of controller circuit <NUM>, e.g., one of impedance input ports ZIN-A, ZIN-B. ZIN-X and/or impedance input ports ZIN-<NUM>, ZIN-<NUM>.

More particularly, connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, and connection end <NUM>-<NUM> are electrically and communicatively connected to impedance input ports ZIN-A, ZIN-B. ZIN-X of A/D converter circuit <NUM> of controller circuit <NUM> and receive impedance inputs for tissue impedance/composition determinations from sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, and sensing end <NUM>-<NUM>. A circumferential arrangement of sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, and sensing end <NUM>-<NUM> is located at distal end portion <NUM>-<NUM> of elongate stylet <NUM> near distal end <NUM>-<NUM> having the sharp distal tip. This circumferential arrangement of sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, and sensing end <NUM>-<NUM>, alone or in combination with sensing end <NUM>-<NUM> positioned near distal end <NUM>-<NUM>, provides tissue impedance information to the controller circuit <NUM>.

Connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, and connection end <NUM>-<NUM> are electrically and communicatively connected to impedance input ports ZIN-<NUM>, ZIN-<NUM>. ZIN-N of A/D converter circuit <NUM> of controller circuit <NUM> (see also <FIG>) and receive impedance inputs for probe penetration depth determinations from sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, and sensing end <NUM>-<NUM>. A longitudinally spaced arrangement of sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, and sensing end <NUM>-<NUM> is located along distal end portion <NUM>-<NUM> of elongate stylet <NUM> to provide penetration depth information to controller circuit <NUM>.

Optionally, a longitudinally spaced arrangement of multiple circumferential metallic bands <NUM> may be located along a lengthwise extent of distal end portion <NUM>-<NUM> of elongate stylet <NUM> to expand the sensing area of a defined subset of the plurality of conductive wire electrodes <NUM>. In the present embodiment, the multiple circumferential metallic bands <NUM> include a circumferential metallic band <NUM>-<NUM>, a circumferential metallic band <NUM>-<NUM>, a circumferential metallic band <NUM>-<NUM>, a circumferential metallic band <NUM>-<NUM>, and a circumferential metallic band <NUM>-<NUM>. Each of the multiple circumferential metallic bands <NUM> surround distal end portion <NUM>-<NUM> of elongate stylet <NUM>, with insulation material interposed between each of the multiple circumferential metallic bands <NUM> and elongate stylet <NUM>. In the present embodiment, circumferential metallic band <NUM>-<NUM>, circumferential metallic band <NUM>-<NUM>, circumferential metallic band <NUM>-<NUM>, circumferential metallic band <NUM>-<NUM>, and circumferential metallic band <NUM>-<NUM> are respectively electrically connected to the longitudinally spaced arrangement of sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, and sensing end <NUM>-<NUM> of conductive wire electrodes, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> to provide penetration depth information to controller circuit <NUM>.

<FIG> show an alternative configuration of a coaxial cannula that is configured as an impedance measuring probe, wherein the coaxial cannula includes one or more conductive wire electrodes. In particular, there is shown a coaxial cannula <NUM> having a hub <NUM> and a tubular member <NUM>. Hub <NUM> may be formed from plastic, e.g., a rigid polymer. Tubular member (cannula) <NUM> is an elongate tubular structure having a tubular side wall <NUM>, and may be formed from metal, such as stainless steel. Tubular side wall <NUM> has a proximal end <NUM>-<NUM>, a distal end <NUM>-<NUM>, a proximal end portion <NUM>-<NUM>, a lumen <NUM>-<NUM>, a distal end portion <NUM>-<NUM>, an elongate interior surface <NUM>, and an elongate exterior surface <NUM>. Proximal end portion <NUM>-<NUM> extends distally from proximal end <NUM>-<NUM>. Hub <NUM> is fixedly attached, e.g., by adhesive, to proximal end portion <NUM>-<NUM> of tubular side wall <NUM>. Hub <NUM> may serve as a user handhold and as a mounting feature for attachment to housing <NUM> of biopsy driver <NUM>. Lumen <NUM>-<NUM> is sized to slidably receive a stylet, such as one of elongate stylet <NUM> and elongate stylet <NUM>, or alternatively, a passive stylet that may not include any conductive wire electrodes.

In accordance with an aspect of the present invention, elongate exterior surface <NUM> has at least one longitudinal channel <NUM>-<NUM>, and in the present embodiment, elongate exterior surface <NUM> has a plurality of recessed longitudinal channels <NUM>, individually identified as longitudinal channel <NUM>-<NUM>, longitudinal channel <NUM>-<NUM>, longitudinal channel <NUM>-<NUM>, and longitudinal channel <NUM>-<NUM>. Each of the plurality of recessed longitudinal channels <NUM> extends from proximal end portion <NUM>-<NUM> and into distal end portion <NUM>-<NUM>, and with each recessed longitudinal channel <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> having a radial depth, i.e., a depth in the direction toward lumen <NUM>-<NUM> that extends along the lengthwise extent of coaxial cannula <NUM>.

Each of connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, and connection end <NUM>-<NUM> extends from proximal end portion <NUM>-<NUM> of tubular side wall <NUM>, and each is respectively electrically and communicatively coupled to one of the multiple impedance input ports <NUM> of A/D converter circuit <NUM> of controller circuit <NUM>, e.g., one of impedance input ports ZIN-A, ZIN-B. ZIN-X and/or impedance input ports ZIN-<NUM>, ZIN-<NUM>. Each of sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, and sensing end <NUM>-<NUM> is located at distal end portion <NUM>-<NUM> of coaxial cannula <NUM>.

Insulation material <NUM>, such as a non-conductive polymer, e.g., silicone rubber, is disposed in each recessed longitudinal channel <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> and around the respective conductive wire electrode <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> so as to electrically insulate the respective conductive wire electrode <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> from tubular member <NUM> of coaxial cannula <NUM>, and from any elongate stylet (e.g., elongate stylet <NUM> or elongate stylet <NUM>) that is inserted into coaxial cannula <NUM>. Insulation material <NUM> encapsulates a lengthwise portion of the conductive wire electrode between the connection end and the sensing end, with the respective ends being free of insulation material to allow electrical contact or connection.

In the present embodiment, insulation material <NUM> fills each recessed longitudinal channel of the plurality of recessed longitudinal channels <NUM>. The distal extent of insulation material <NUM> terminates prior to covering sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, and sensing end <NUM>-<NUM> of the plurality of conductive wire electrodes <NUM>, such that sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, sensing end <NUM>-<NUM>, and sensing end <NUM>-<NUM> are exposed at distal end portion <NUM>-<NUM> of coaxial cannula <NUM>. Likewise, the proximal extent of insulation material <NUM> terminates prior to covering connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, and connection end <NUM>-<NUM> of the plurality of conductive wire electrodes <NUM>, such that connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, connection end <NUM>-<NUM>, and connection end <NUM>-<NUM> are exposed and available for connection to A/D converter circuit <NUM> of controller circuit <NUM> (see also <FIG>).

<FIG> shows an alternative recessed channel arrangement in tubular member <NUM> of coaxial cannula <NUM>, wherein elongate interior surface <NUM> has the plurality of recessed longitudinal channels <NUM>, and wherein each recessed longitudinal channel <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> receives the respective conductive wire electrode <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>. Again, insulation material <NUM>, such as a non-conductive polymer, e.g., silicone rubber, is disposed in each recessed longitudinal channel <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> and around the respective conductive wire electrode <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> so as to electrically insulate the respective conductive wire electrode <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> from tubular member <NUM> of coaxial cannula <NUM>, and from any elongate stylet (e.g., elongate stylet <NUM> or elongate stylet <NUM>) that is inserted into coaxial cannula <NUM>.

Further, it is contemplated that each of the elongate interior surface <NUM> and the elongate exterior surface <NUM> of tubular member <NUM> may have one or more of the plurality of recessed longitudinal channels <NUM> and one or more of the plurality of conductive wire electrodes <NUM>.

Further, it is contemplated that each of elongate stylet <NUM> and elongate stylet <NUM> may be formed from a tubular member, such as tubular member <NUM> having any of the arrangements of the plurality of recessed longitudinal channels <NUM> described above for receiving one or more conductive wire electrodes.

In all embodiments, impedance may be measured between any two electrode sensing ends of two corresponding conductive wire electrodes, or alternatively, between a sensing end of a conductive wire electrode and a metal conductor serving as an electrical common electrical path, such as the metal elongate member, e.g., one of the elongate stylet or the tubular member of the coaxial cannula, or an electrode sensing end of a conductive wire electrode predefined to serve as a common electrical path, e.g., sensing end <NUM>-<NUM>.

Further, in all embodiments, alternatively or supplemental to the above, it is contemplated that insulation material may be applied to, or formed on, the respective conductive wire electrode prior to insertion into a respective recessed longitudinal channel of the impedance measuring probe.

As used herein, "near" is a relative modifier intended to indicate permissible variation from the characteristic so modified. To the extent that a specific interpretation is required, for purposes of the present invention, "near" may mean less than <NUM> from the referenced structure.

The following items also relate to the invention:
Disclosed is an impedance measuring probe for use in a biopsy apparatus. The impedance measuring probe includes an elongate member, e.g., metal, having a longitudinal axis, an elongate surface, a proximal end, a distal end, a proximal end portion that extends distally from the proximal end, and a distal end portion that extends proximally from the distal end. The elongate surface has a recessed longitudinal channel having a radial depth that longitudinally extends from the proximal end portion into the distal end portion. A conductive wire electrode, having a connection end and a sensing end, is located in and extends along the recessed longitudinal channel. The connection end extends from the proximal end portion of the elongate member and the sensing end is located at the distal end portion of the elongate member. An insulation material is disposed in the recessed longitudinal channel of the elongate member and around the conductive wire electrode so as to electrically insulate the conductive wire electrode. The sensing end of the conductive wire electrode is exposed at the distal end portion of the elongate member. The impedance measuring probe may be configured to measure the impedance at the sensing end of the conductive wire.

Optionally, the elongate member may be a solid metal stylet having an outer surface, wherein the outer surface of the stylet is the elongate surface having the recessed longitudinal channel.

Also, optionally, the elongate member may be a tubular member having a tubular side wall that defines a lumen, an exterior surface, and an interior surface, wherein the exterior surface is the elongate surface having the recessed longitudinal channel.

Also, optionally, the elongate member may be a tubular member having a tubular side wall that defines a lumen and an interior surface, wherein the interior surface is the elongate surface having the recessed longitudinal channel.

In all of the configurations of the impedance measuring probe, the insulation material may fill the recessed longitudinal channel.

In an embodiment, a plurality of conductive wire electrodes may be located in and extends along the recessed longitudinal channel, wherein the insulation material electrically insulates the plurality of conductive wire electrodes from one another and from the metal elongate member. Each conductive wire electrode of the plurality of conductive wire electrodes has a connection end and a sensing end, with the connection end extending from the proximal end portion of the metal elongate member and the sensing end being located at the distal end portion of the metal elongate member.

In another embodiment, the elongate member has a plurality of recessed longitudinal channels that extend from the proximal end portion and into the distal end portion. Each conductive wire electrode of a plurality of conductive wire electrodes may be located in and extends along a respective recessed longitudinal channel of the plurality of recessed longitudinal channels, with each conductive wire electrode of the plurality of conductive wire electrodes having a connection end extending from the proximal end portion of the metal elongate member and a sensing end located in the distal end portion of the elongate member. Insulation material is disposed in the plurality of recessed longitudinal channels of the elongate member and around a respective conductive wire electrode of the plurality of conductive wire electrodes so as to electrically insulate the respective conductive wire electrode. The sensing end of each respective conductive wire electrode of the plurality of conductive wire electrodes is exposed at the distal end portion of the elongate member.

A circumferential arrangement of multiple sensing ends may be located at the distal end portion of the elongate member near a distal tip of the elongate member. The circumferential arrangement of the multiple sensing ends may be configured to provide tissue impedance information.

Optionally, a longitudinally spaced arrangement of multiple sensing ends may be located along the distal end portion of the elongate member. The longitudinally spaced arrangement of multiple sensing ends may be configured to provide penetration depth information.

Optionally, a longitudinally spaced arrangement of multiple circumferential metallic bands may surround the distal end portion of the metal elongate member, with insulation material interposed between the multiple circumferential metallic bands and the metal elongate member. The multiple circumferential metallic bands may be respectively electrically connected to the longitudinally spaced arrangement of multiple sensing ends.

In all embodiments, the elongate member may be one of a solid stylet and a tubular member having a tubular side wall. In all embodiments having a plurality of conductive wire electrodes, four conductive wire electrodes may be provided and/or the conductive wire electrodes may equidistantly be spaced along the circumference, optionally with an angle of <NUM>° relative to each other.

Also disclosed is a biopsy apparatus. The biopsy apparatus includes a biopsy driver having a housing that carries a controller circuit and a motor. The controller circuit is electrically and communicatively coupled to the motor. The motor has a motor shaft. An elongate stylet, i.e. metal, has an elongate surface, a proximal end, a distal end, a proximal end portion that extends distally from the proximal end, and a distal end portion that extends proximally from the distal end. The proximal end portion is drivably coupled to the motor shaft of the motor. The elongate surface has a plurality of recessed longitudinal channels that extends from the proximal end portion and into the distal end portion. Each recessed longitudinal channel of the plurality of recessed longitudinal channels has a radial depth. At least one conductive wire electrode is positioned in each channel of the plurality of recessed longitudinal channels, wherein each conductive wire electrode is located in and extends along a respective recessed longitudinal channel of the plurality of recessed longitudinal channels. Each conductive wire electrode has a connection end that extends from the proximal end portion of the elongate stylet and has a sensing end that is located in the distal end portion of the elongate stylet. The connection end is electrically connected to the controller circuit. Insulation material is disposed in the plurality of recessed longitudinal channels of the elongate stylet and around each respective conductive wire electrode so as to electrically insulate each respective conductive wire electrode. The sensing end of each respective conductive wire electrode is exposed at the distal end portion of the elongate stylet. The impedance measuring probe may be configured to measure the impedance at the sensing end of the conductive wire. In the embodiments having a plurality of conductive wire electrodes, four conductive wire electrodes may be provided and/or the conductive wire electrodes may equidistantly be spaced along the circumference, optionally with an angle of <NUM>° relative to each other.

Optionally, a circumferential arrangement of multiple sensing ends may located at the distal end portion of the elongate metal stylet near the distal tip. The circumferential arrangement of the multiple sensing ends may be configured to provide tissue impedance information to the controller circuit.

Also, optionally, a longitudinally spaced arrangement of multiple sensing ends may be located along the distal end portion of the elongate metal stylet. The longitudinally spaced arrangement of multiple sensing ends may be configured to provide penetration depth information to the controller circuit.

As a further option, a longitudinally spaced arrangement of multiple circumferential metallic bands may surround the distal end portion of the elongate metal stylet, with insulation material interposed between the multiple circumferential metallic bands and the elongate metal stylet. The multiple circumferential metallic bands may be respectively electrically connected to the longitudinally spaced arrangement of multiple sensing ends.

The biopsy apparatus may further include a coaxial cannula having a hub and a tubular member, the tubular member having a tubular side wall having a proximal end, a distal end, and a distal end portion that extends proximally from the distal end, and the side wall defining a lumen. The elongate metal stylet may be positioned in the lumen. The tubular member may have at least one recessed longitudinal channel formed in the tubular side wall that extends along a longitudinal extent of the tubular side wall of the tubular member. In this example, at least one additional conductive wire electrode may be positioned in each recessed longitudinal channel of the tubular member, and each additional conductive wire electrode may be electrically insulated from the tubular member by insulation material, and each additional conductive wire electrode has a connection end electrically connected to the controller circuit and an exposed sensing end.

Also disclosed is impedance measuring probe arrangement for use with a biopsy apparatus. The impedance measuring probe includes a tubular member having a tubular side wall that has a first proximal end, a first distal end, and a first distal end portion that extends proximally from the first distal end. The tubular side wall defines a lumen. An elongate stylet, i.e. metal, is positioned in the lumen. The elongate stylet has a second proximal end, a second distal end and a second distal end portion that extends proximally from the second distal end. At least one recessed longitudinal channel is formed in one of, or both of, the tubular side wall of the tubular member and the elongate stylet, wherein each recessed longitudinal channel extends along a longitudinal extent of one of the tubular side wall of the tubular member and the elongate stylet. At least one conductive wire electrode is positioned in each recessed longitudinal channel. The conductive wire electrode is electrically insulated from the tubular member and the elongate stylet by insulation material. Each conductive wire electrode has a connection end and a sensing end. The impedance measuring probe may be configured to measure the impedance at the sensing end of the conductive wire.

The tubular side wall may define an exterior surface and an interior surface, wherein a respective recessed longitudinal channel may be located on at least one of the exterior surface and the interior surface.

Optionally, the tubular side wall of the tubular member may have a plurality of recessed longitudinal channels and a plurality of conductive wire electrodes. Each recessed longitudinal channel of the plurality of recessed longitudinal channels has positioned therein at least one conductive wire electrode of the plurality of conductive wire electrodes, with each conductive wire electrode of the plurality of conductive wire electrodes having a connection end extending from the first proximal end portion of the tubular side wall configured for connection to a controller circuit of the biopsy apparatus and having a sensing end located in the first distal end portion of the tubular side wall. Insulation material is disposed in the plurality of recessed longitudinal channels of the tubular side wall and around each respective conductive wire electrode of the plurality of conductive wire electrodes so as to electrically insulate each respective conductive wire electrode, and wherein the sensing end of each respective conductive wire electrode of the plurality of conductive wire electrodes is exposed at the first distal end portion of the tubular side wall.

Optionally, a circumferential arrangement of multiple sensing ends may be located at the first distal end portion of the tubular side wall. The circumferential arrangement of the multiple sensing ends may be configured to provide tissue impedance information to the controller circuit.

Also, optionally, the elongate metal stylet may have a plurality of recessed longitudinal channels, and a plurality of conductive wire electrodes. Each recessed longitudinal channel of the plurality of recessed longitudinal channels has positioned therein at least one conductive wire electrode of the plurality of conductive wire electrodes, with each conductive wire electrode of the plurality of conductive wire electrodes having a connection end extending from the second proximal end portion of the elongate metal stylet configured for connection to a controller circuit of the biopsy apparatus and having a sensing end located in the second distal end portion of the elongate metal stylet. Insulation material is disposed in the plurality of recessed longitudinal channels of the tubular side wall and around each respective conductive wire electrode of the plurality of conductive wire electrodes so as to electrically insulate each respective conductive wire electrode, and wherein the sensing end of each respective conductive wire electrode of the plurality of conductive wire electrodes is exposed at the second distal end portion of the elongate metal stylet.

Optionally, a circumferential arrangement of multiple sensing ends may be located at the second distal end portion of the elongate metal stylet. The circumferential arrangement of the multiple sensing ends may be configured to provide tissue impedance information to the controller circuit.

Also, optionally, a longitudinally spaced arrangement of multiple sensing ends may be located along the second distal end portion of the metal elongate member. The longitudinally spaced arrangement of multiple sensing ends may be configured to provide penetration depth information to the controller circuit. In all embodiments having a plurality of conductive wire electrodes, four conductive wire electrodes may be provided and/or the conductive wire electrodes may equidistantly be spaced along the circumference, optionally with an angle of <NUM>° relative to each other.

Claim 1:
An impedance measuring probe for use in a biopsy apparatus (<NUM>), comprising:
a metal elongate member (<NUM>) having a longitudinal axis (<NUM>-<NUM>), an elongate surface (<NUM>), a proximal end (<NUM>-<NUM>), a distal end (<NUM>-<NUM>), a proximal end portion (<NUM>-<NUM>) that extends distally from the proximal end (<NUM>-<NUM>), and a distal end portion (<NUM>-<NUM>) that extends proximally from the distal end (<NUM>-<NUM>), the impedance measuring probe characterized by:
the elongate surface (<NUM>) having a recessed longitudinal channel (<NUM>-<NUM>) having a radial depth that longitudinally extends from the proximal end portion (<NUM>-<NUM>) into the distal end portion (<NUM>-<NUM>);
a plurality of conductive wire electrodes (<NUM>), each conductive wire electrode of the plurality of conductive wire electrodes having a connection end (<NUM>-<NUM>) and a sensing end (<NUM>-<NUM>), each conductive wire electrode (<NUM>) of the plurality of conductive wire electrodes located in and extends along the recessed longitudinal channel (<NUM>-<NUM>), the connection end (<NUM>-<NUM>) extending from the proximal end portion (<NUM>-<NUM>) of the metal elongate member (<NUM>) and the sensing end (<NUM>-<NUM>) being located at the distal end portion (<NUM>-<NUM>) of the metal elongate member (<NUM>); and
an insulation material (<NUM>) disposed in the recessed longitudinal channel (<NUM>-<NUM>) of the metal elongate member (<NUM>) and around the conductive wire electrodes (<NUM>) so as to electrically insulate the conductive wire electrodes (<NUM>), and with the sensing end (<NUM>-<NUM>) of the conductive wire electrode (<NUM>) being exposed at the distal end portion (<NUM>-<NUM>) of the metal elongate member (<NUM>).