Patent Description:
The present invention relates to biopsy devices for sampling tissue, and, more particularly, to a biopsy device having a hydraulic drive assembly.

A biopsy may be performed on a patient to help in determining whether the cells in a biopsied region are cancerous. One type of biopsy device for performing a biopsy includes a hand-held driver assembly having an electromechanical driver that is attachable to a disposable biopsy probe assembly. The biopsy device typically includes springloaded components that, when moved, intermittently contact other components, resulting in significant noise.

What is needed in the art is a biopsy device having a hydraulic drive assembly that operates in conjunction with electromechanical components to reduce or eliminate intermittent contact between movable components, thereby providing a noise reduction of the biopsy device.

<CIT> is considered the closest prior art and discloses an endoscopic apparatus having a distal end for insertion into a body of a patient and a proximal end that is held outside the body of the patient. The apparatus includes a proximal cylinder, disposed in a vicinity of the proximal end of the endoscopic apparatus. A proximal piston is slidably contained within the proximal cylinder. A distal cylinder is disposed in a vicinity of the distal end of the endoscopic apparatus, and a distal piston is slidably contained within the distal cylinder. A tube for containing a liquid is coupled between the proximal and distal cylinders. A tool (e.g., biopsy tool) is coupled to be actuated by displacement of the distal piston, so as to perform a mechanical action on tissue of the body or contents of the body, responsive to displacement of the distal piston.

According to the invention there is provided a biopsy device according to claim <NUM>.

The present invention provides a biopsy device having a hydraulic drive assembly that operates in conjunction with electromechanical components to reduce or eliminate intermittent contact between movable components, thereby providing a noise reduction of the biopsy device.

An example not according to the claims is directed to a biopsy device that includes a hydraulic drive assembly, a drive mechanism, and an elongate biopsy member. The hydraulic drive assembly includes a chamber housing configured to define a proximal chamber, a distal chamber, and a transition chamber. The transition chamber is interposed between the proximal chamber and the distal chamber, wherein the proximal chamber, the transition chamber, and the distal chamber collectively form a continuous passage in the chamber housing. The proximal chamber has a first transverse area and the distal chamber has a second transverse area, with the first transverse area being larger than the second transverse area. A drive piston is located in the proximal chamber and is configured to move in the proximal chamber. A driven piston is located in the distal chamber and is configured to move in the distal chamber. A cavity is defined in the chamber housing between the drive piston and the driven piston. A hydraulic fluid of a fixed quantity fills the cavity between the drive piston and the driven piston to establish a hydraulic connection between the drive piston and the driven piston. The drive mechanism is drivably connected to the drive piston. The drive mechanism is configured to move the drive piston in the proximal cylinder. The elongate biopsy member is connected to the driven piston.

Another example not according to the claims is directed to a biopsy device that includes a chamber housing configured to define a proximal cylinder, a distal cylinder, and a transition chamber interposed between the proximal cylinder and the distal cylinder. The chamber housing has a longitudinal axis with the proximal cylinder being separated from the distal cylinder by the transition chamber along the longitudinal axis. The proximal cylinder has a first diameter, and the distal cylinder has a second diameter, with the first diameter being larger than the second diameter. A drive piston is located in the proximal cylinder. A drive source has a motor coupled to a mechanical drive train. The mechanical drive train is connected to the drive piston. The drive source is configured to move the drive piston in the proximal cylinder along the longitudinal axis. A driven piston is located in the distal cylinder. The driven piston is configured to move in the distal cylinder along the longitudinal axis. A cavity is defined in the chamber housing between the drive piston and the driven piston, with the cavity including the transition chamber. A hydraulic fluid of a fixed quantity fills the cavity between the drive piston and the driven piston. A cannula is connected to the driven piston.

The invention is directed to a biopsy device that includes a chamber housing having a proximal chamber, a transition chamber, and a distal chamber that form a continuous passage in the chamber housing. The proximal chamber, the transition chamber, and the distal chamber are arranged along a longitudinal axis. The proximal chamber has a first cylindrical side wall that has a first proximal end and a first distal end. The transition chamber has a frustoconical side wall that has a base end and a narrowed end. The distal chamber has a second cylindrical side wall that has a second proximal end and a second distal end. The base end of the frustoconical side wall is joined to the first distal end of the first cylindrical side wall and the narrowed end of the frustoconical side wall is joined to the second proximal end of the second cylindrical side wall. A drive piston is located in the proximal chamber. A drive source is connected to the drive piston, and the drive source is configured to move the drive piston in the proximal chamber along the longitudinal axis. A driven piston is located in the distal chamber. The driven piston is configured to move in the distal chamber along the longitudinal axis. A cavity is defined in the chamber housing between the drive piston and the driven piston. A hydraulic fluid of a fixed quantity fills the cavity between the drive piston and the driven piston. An elongate biopsy member is connected to the driven piston. Due to the configuration of the proximal chamber, transition chamber and distal chamber, a displacement of the drive piston results in an amplified displacement of the driven piston.

An advantage of the present invention is that the hydraulic drive assembly, e.g., having the drive piston and driven piston arrangement, eliminates the need for a mechanism having propelling/retracting springs, as in a typical biopsy driver.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate at least one embodiment 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 device <NUM> which generally includes a driver assembly <NUM> and a disposable biopsy needle assembly <NUM>. In the present embodiment, driver assembly <NUM> may be reusable on multiple patients, whereas disposable biopsy needle assembly <NUM> is used only on a single patient. Alternatively, driver assembly <NUM> also may be disposable. As used herein, the term "disposable" refers to a device that is intended for use with one patient only and is discarded after use.

Disposable biopsy needle assembly <NUM> includes an elongate biopsy member <NUM> and a connector <NUM>. In the present embodiment, elongate biopsy member <NUM>, such as a cannula, has a lumen <NUM>-<NUM>, a beveled piercing tip portion <NUM>-<NUM> that defines an annular cutting edge <NUM>-<NUM>, and a piercing tip <NUM>-<NUM>. Those skilled in the art will recognize that elongate biopsy member <NUM> may have other tip configurations, such as blunted or forming a closed point, and may be used in conjunction with another coaxial cannula.

Connector <NUM> is fixedly attached to a proximal portion <NUM>-<NUM> of elongate biopsy member <NUM>. Connector <NUM> is configured for releasable attachment to a needle mount interface <NUM> of driver assembly <NUM> (see also <FIG>). Connector <NUM> may be, for example, a screw-type connector, a bayonet mount, a snap-fit connector, or other suitable mechanism used to releasably connect two components.

Referring to <FIG>, driver assembly <NUM> includes a handle housing <NUM>. Handle housing <NUM> includes a window <NUM> for accessing a user interface circuit <NUM>. User interface circuit <NUM> is configured to receive a user input and generate a user output signal. In the present embodiment, user interface circuit <NUM> may be a simple touch pad having a plurality of control buttons <NUM>, individually identified as needle extend button <NUM>-<NUM> and needle retract button <NUM>-<NUM>. Alternatively, it is contemplated that user interface circuit <NUM> may be a digital touch screen display.

Referring also to <FIG>, handle housing <NUM> includes an interior open space to contain an electrical control circuit <NUM>, an electrical power source <NUM>, an electromechanical drive mechanism <NUM>, and a hydraulic drive assembly <NUM>. Electrical control circuit <NUM> is electrically coupled to electrical power source <NUM> to receive electrical power therefrom. Electrical power source <NUM> may be, for example, a rechargeable battery sized to have electrical capacity sufficient to supply the electrical power requirements of electrical control circuit <NUM>, user interface circuit <NUM>, and electromechanical drive mechanism <NUM>. Those skilled in the art will recognize that user interface circuit <NUM> may receive power via electrical control circuit <NUM>, or alternatively, from electrical power source <NUM>. Likewise, those skilled in the art will recognize that electromechanical drive mechanism <NUM> may receive power via electrical control circuit <NUM>, or alternatively, from electrical power source <NUM>.

Electrical control circuit <NUM> includes a microcontroller <NUM>-<NUM>, a motor interface circuit <NUM>-<NUM>, and a sensor circuit <NUM>-<NUM>.

Microcontroller <NUM>-<NUM> includes a microprocessor, on-board non-transitory electronic memory, and component interface circuitry, as is known in the art. Microcontroller <NUM>-<NUM> is configured to execute program instructions to generate motor control signals to control the extension and retraction of disposable biopsy needle assembly <NUM>, based on the user output signal received from user interface circuit <NUM>.

Motor interface circuit <NUM>-<NUM> is communicatively coupled to microcontroller <NUM>-<NUM> to receive the motor control signals. Motor interface circuit <NUM>-<NUM> includes power interface circuitry to supply electrical power, which may be in the form of control signals, to electromechanical drive mechanism <NUM>.

Sensor circuit <NUM>-<NUM> may include, for example, an optical sensor, Hall-effect sensor, etc. that supplies a sensor output signal to microcontroller <NUM>-<NUM>. In particular, sensor circuit <NUM>-<NUM> is located to sense a movement of a moveable component of electromechanical drive mechanism <NUM>, such as a rotation of a drive gear or driven gear, as will be described in further detail below, and in turn to supply the sensor output signal corresponding to the sensed movement of the movable component of electromechanical drive mechanism <NUM> to microcontroller <NUM>-<NUM>.

Electromechanical drive mechanism <NUM> includes a motor <NUM> and a mechanical drive train <NUM>. Mechanical drive train <NUM> is coupled to receive rotary power from motor <NUM>. Motor <NUM> may be, for example, a stepper motor or a DC (direct current) motor. Motor <NUM> receives electrical power, which may be in the form of control signals, from motor interface circuit <NUM>-<NUM> of electrical control circuit <NUM>, and in turn provides rotary power to electromechanical drive mechanism <NUM> (see also <FIG>), as directed by electrical control circuit <NUM>. As will be further described below, electromechanical drive mechanism <NUM> is configured to convert the rotary power received from motor <NUM> into linear power, which is supplied to hydraulic drive assembly <NUM>.

<FIG> is a side view of hydraulic drive assembly <NUM>, which is connected to disposable biopsy needle assembly <NUM>. Hydraulic drive assembly <NUM> includes a chamber housing <NUM>. Chamber housing <NUM> is arranged along a longitudinal axis <NUM>.

Each of <FIG> shows a side view of the electromechanical drive mechanism <NUM> and the hydraulic drive assembly <NUM>, with hydraulic drive assembly <NUM> shown in cross-section along line <NUM>-<NUM> of <FIG>. Electromechanical drive mechanism <NUM>, serving as a drive source, is connected to hydraulic drive assembly <NUM>.

Electromechanical drive mechanism <NUM> includes motor <NUM> and mechanical drive train <NUM>. Motor <NUM> has a rotatable shaft <NUM>-<NUM>. Mechanical drive train <NUM> includes a drive gear <NUM>-<NUM>, a driven gear <NUM>-<NUM>, and a drive link member <NUM>-<NUM>. Drive gear <NUM>-<NUM> is fixedly attached to rotatable shaft <NUM>-<NUM> of motor <NUM>, such that drive gear <NUM>-<NUM> rotates in unison with the rotation of rotatable shaft <NUM>-<NUM>. Driven gear <NUM>-<NUM> is engaged, i.e., in mesh, with drive gear <NUM>-<NUM>. Driven gear <NUM>-<NUM> is configured for mounting to handle housing <NUM>, e.g., through bearing coupling to handle housing <NUM>, and is located to rotate about a first rotational axis <NUM>. The first rotational axis <NUM> of driven gear <NUM>-<NUM> is oriented to be substantially orthogonal to longitudinal axis <NUM>, and in the present embodiment may further be oriented such that longitudinal axis <NUM> intersects first rotational axis <NUM>. As used herein, the term "substantially orthogonal" equates to substantially perpendicular, and is defined to mean an angular relationship between two elements of <NUM> degrees, plus or minus <NUM> degrees.

Drive link member <NUM>-<NUM> may be configured as an elongate plate or rod, to facilitate a mechanical coupling of the driven gear to a movable drive component, e.g., a drive piston <NUM>, of hydraulic drive assembly <NUM>. Drive piston <NUM> has a first proximal end portion <NUM>-<NUM> and a first distal end portion <NUM>-<NUM>. Drive link member <NUM>-<NUM> has a first end portion <NUM>-<NUM> and a second end portion <NUM>-<NUM> spaced apart from the first end portion <NUM>-<NUM>.

A first connector <NUM> connects the first end portion <NUM>-<NUM> of drive link member <NUM>-<NUM> to driven gear <NUM>-<NUM>. First connector <NUM> defines a second rotational axis <NUM> on driven gear <NUM>-<NUM> that is radially offset by an offset distance <NUM> from the first rotational axis <NUM>. First connector <NUM> may be, for example, a pin/hole arrangement, wherein the first end portion <NUM>-<NUM> of drive link member <NUM>-<NUM> is rotatable about the second rotational axis <NUM> when a driving force is supplied by driven gear <NUM>-<NUM> to the first end portion <NUM>-<NUM> of drive link member <NUM>-<NUM> via first connector <NUM>.

A second connector <NUM> connects the second end portion <NUM>-<NUM> of drive link member <NUM>-<NUM> to the movable drive component, e.g., drive piston <NUM>, of hydraulic drive assembly <NUM>. In the present embodiment, second connector <NUM> connects the second end portion <NUM>-<NUM> of drive link member <NUM>-<NUM> to the first proximal end portion <NUM>-<NUM> of drive piston <NUM>. Second connector <NUM> defines a pivot axis <NUM> at the first proximal end portion <NUM>-<NUM> of drive piston <NUM>. The pivot axis <NUM> is oriented to be substantially orthogonal to the longitudinal axis <NUM>, and in the present embodiment may further be oriented such that longitudinal axis <NUM> intersects the pivot axis <NUM>. Second connector <NUM> may be, for example, a pin/hole arrangement, wherein the second end portion <NUM>-<NUM> of drive link member <NUM>-<NUM> is pivotable about the pivot axis <NUM> when the driving force is transferred by drive link member <NUM>-<NUM> to the first proximal end portion <NUM>-<NUM> of drive piston <NUM>, via second connector <NUM>.

Hydraulic drive assembly <NUM> includes chamber housing <NUM> having a side wall <NUM>-<NUM> that is configured to define a proximal chamber <NUM>, a distal chamber <NUM>, and a transition chamber <NUM>. Chamber housing <NUM> includes a hydraulic fluid fill passage <NUM>-<NUM> in the form of a cylindrical bore that extends through side wall <NUM>-<NUM>. A removable fill plug <NUM>-<NUM> is sealably received in hydraulic fluid fill passage <NUM>-<NUM> of chamber housing <NUM>, e.g., by press fit, or by a threaded connection between removable fill plug <NUM>-<NUM> and hydraulic fluid fill passage <NUM>-<NUM>, with sealing tape or a seal coating applied to the threads.

Chamber housing <NUM> is positioned on longitudinal axis <NUM>, with the proximal chamber <NUM> being separated from the distal chamber <NUM> by transition chamber <NUM> along longitudinal axis <NUM>. In other words, transition chamber <NUM> is interposed between the proximal chamber <NUM> and the distal chamber <NUM>. Proximal chamber <NUM>, transition chamber <NUM>, and distal chamber <NUM> form, collectively, a continuous passage in chamber housing <NUM> along longitudinal axis <NUM>, with the continuous passage extending between the opposite end surfaces of chamber housing <NUM> along longitudinal axis <NUM>.

Proximal chamber <NUM> has a first cylindrical side wall <NUM>-<NUM> having a first proximal end <NUM>-<NUM> and a first distal end <NUM>-<NUM>, thereby defining a proximal cylinder. Distal chamber <NUM> has a second cylindrical side wall <NUM>-<NUM> having a second proximal end <NUM>-<NUM> and a second distal end <NUM>-<NUM>, thereby defining a distal cylinder. Transition chamber <NUM> has a frustoconical side wall <NUM>-<NUM> having a base end <NUM>-<NUM> and a narrowed end <NUM>-<NUM>. The base end <NUM>-<NUM> of the frustoconical side wall <NUM>-<NUM> is joined to the first distal end <NUM>-<NUM> of the first cylindrical side wall <NUM>-<NUM> of proximal chamber <NUM>, and the narrowed end <NUM>-<NUM> of frustoconical side wall <NUM>-<NUM> is joined to the second proximal end <NUM>-<NUM> of the second cylindrical side wall <NUM>-<NUM> of distal chamber <NUM>. First cylindrical side wall <NUM>-<NUM>, frustoconical side wall <NUM>-<NUM>, and second cylindrical side wall <NUM>-<NUM> are formed as a continuous interior surface of chamber housing <NUM>.

Drive piston <NUM> is located in the proximal chamber <NUM>, with the first proximal end portion <NUM>-<NUM> of drive piston <NUM> extending in a proximal direction from chamber housing <NUM>, and with at least first distal end portion <NUM>-<NUM> of drive piston <NUM> movably residing in proximal chamber <NUM>. The first distal end portion <NUM>-<NUM> of drive piston <NUM> has a piston head <NUM>-<NUM> and an annular slot <NUM>-<NUM> that receives a seal member <NUM>-<NUM>, such as a rubber O-ring, that annularly engages first cylindrical side wall <NUM>-<NUM> of proximal chamber <NUM>.

The first proximal end portion <NUM>-<NUM> of drive piston <NUM> is connected to the second end portion <NUM>-<NUM> of drive link member <NUM>-<NUM> of mechanical drive train <NUM> of electromechanical drive mechanism <NUM>, via first connector <NUM>. Electromechanical drive mechanism <NUM>, as controlled by electrical control circuit <NUM>, is configured to move, i.e., linearly displace, the drive piston <NUM> in proximal chamber <NUM> along the longitudinal axis <NUM>.

An optional guide rod <NUM> may be fixedly attached to drive piston <NUM>, e.g., by being press fit into a hole in drive piston <NUM>. Guide rod <NUM> extends distally from piston head <NUM>-<NUM> along longitudinal axis <NUM>.

A driven piston <NUM> is located in distal chamber <NUM>. Driven piston <NUM> is configured to move in distal chamber <NUM> along the longitudinal axis <NUM>. Driven piston <NUM> has a second proximal end portion <NUM>-<NUM> and a second distal end portion <NUM>-<NUM>. The second proximal end portion <NUM>-<NUM> of the driven piston <NUM> has a piston tail <NUM>-<NUM> that is in an opposed relationship with piston head <NUM>-<NUM> of drive piston <NUM>, with piston tail <NUM>-<NUM> of driven piston <NUM> being linearly spaced from piston head <NUM>-<NUM> of drive piston <NUM>. The second proximal end portion <NUM>-<NUM> further has an annular slot <NUM>-<NUM> that receives a seal member <NUM>-<NUM>, such as a rubber O-ring, which annularly engages second cylindrical side wall <NUM>-<NUM> of distal chamber <NUM>.

The second distal end portion <NUM>-<NUM> of driven piston <NUM> includes the needle mount interface <NUM> that is configured to releasably connect to elongate biopsy member <NUM> of disposable biopsy needle assembly <NUM> via connector <NUM>. Elongate biopsy member <NUM> is configured to longitudinally extend in a distal direction from needle mount interface <NUM> along longitudinal axis <NUM>.

In an embodiment that includes guide rod <NUM>, driven piston <NUM> includes a guide rod channel <NUM>-<NUM> sized to slidably receive the guide rod <NUM> that is fixedly attached to drive piston <NUM>. As such, guide rod <NUM> may assist in maintaining an axial alignment of drive piston <NUM> and driven piston <NUM>, without any sort of mechanical connection between drive piston <NUM> and driven piston <NUM> along longitudinal axis <NUM>. In addition, guide rod <NUM> is useful in obtaining component alignment during assembly of hydraulic drive assembly <NUM>.

Prior to filling hydraulic drive assembly <NUM> with hydraulic fluid, a cavity <NUM> is defined in chamber housing <NUM> between drive piston <NUM> and driven piston <NUM>, with cavity <NUM> including transition chamber <NUM>. The hydraulic fluid may be, for example, propylene glycol, or a silicone oil based fluid. Hydraulic fluid of a fixed quantity is received through hydraulic fluid fill passage <NUM>-<NUM>, so as to fill cavity <NUM> between drive piston <NUM> and driven piston <NUM>. As used herein, to "fill" cavity <NUM> means to completely occupy the space, i.e., volume, defined by cavity <NUM>. In the present embodiment, hydraulic fluid will completely occupy the space defined by cavity <NUM>, such that all air is removed from cavity <NUM>. In other words, hydraulic fluid is received between drive piston <NUM> and driven piston <NUM>, with each of piston head <NUM>-<NUM> of drive piston <NUM> and piston tail <NUM>-<NUM> of driven piston <NUM> facing the hydraulic fluid. With all air removed from cavity <NUM> in chamber housing <NUM>, fill plug <NUM>-<NUM> is installed to seal cavity <NUM>.

Thus, while there is no mechanical connection between drive piston <NUM> and driven piston <NUM>, there is now a hydraulic connection between drive piston <NUM> and driven piston <NUM>, such that a displacement of drive piston <NUM> along longitudinal axis <NUM> will result in an amplified displacement of driven piston <NUM> along longitudinal axis <NUM>, by virtue of the configuration of the proximal chamber <NUM>, transition chamber <NUM> and distal chamber <NUM>. In other words, driven piston <NUM> and disposable biopsy needle assembly <NUM> will be driven at a faster linear speed than the linear speed of drive piston <NUM>. Also, since hydraulic drive assembly <NUM> is a closed hydraulic system, the instant that motor <NUM> stops rotation of drive gear <NUM>-<NUM>, the linear displacement of elongate biopsy member <NUM> of disposable biopsy needle assembly <NUM> will stop.

In the present embodiment, proximal chamber <NUM> may be a cylinder having a first diameter and distal chamber <NUM> may be a cylinder having a second diameter, wherein the first diameter is larger than the second diameter, and wherein each of the first diameter and the second diameter is transverse, i.e., orthogonal, to the longitudinal axis <NUM>. The first diameter of the cylindrical proximal chamber <NUM> is associated with a corresponding first transverse area within proximal chamber <NUM>, and the second diameter of the cylindrical distal chamber <NUM> is associated with a corresponding second transverse area within distal chamber <NUM>. In one implementation of the present embodiment, for example, the first diameter of proximal chamber <NUM> is <NUM> millimeters (mm) and the second diameter of the distal chamber is <NUM>, which yields a length displacement of driven piston <NUM> that is <NUM> times the displacement of drive piston <NUM> along longitudinal axis <NUM>.

It is also contemplated that at least one of proximal chamber <NUM> and distal chamber <NUM> may be non-cylindrical, e.g., elliptical, in a direction transverse to the direction of piston travel, in which case the relationship between the transverse sizes of proximal chamber <NUM> and distal chamber <NUM> may be better characterized in terms of a respective transverse area that is orthogonal to an axis of the respective chamber, e.g., the transverse area being orthogonal to the direction of piston travel. In the present example, proximal chamber <NUM> has a first transverse area orthogonal to longitudinal axis <NUM> and distal chamber <NUM> has a second transverse area orthogonal to longitudinal axis <NUM>, wherein the direction of piston travel of both drive piston <NUM> and driven piston <NUM> is coincident with longitudinal axis <NUM>, and wherein the first transverse area is larger than the second transverse area.

In operation, referring again to <FIG>, user interface circuit <NUM> includes control buttons <NUM> that receive a user input, and it in turn generates a corresponding user output signal. In the present embodiment, sensor circuit <NUM>-<NUM> is configured and positioned to sense a rotation of driven gear <NUM>-<NUM> and generate a sensor output signal corresponding to the rotation of driven gear <NUM>-<NUM>. Microcontroller <NUM>-<NUM> is in electrical communication with each of user interface circuit <NUM> and sensor circuit <NUM>-<NUM>, and executes program instructions to process each of the user output signal and the sensor output signal, and to supply a motor control signal to motor interface circuit <NUM>-<NUM> to control operation of motor <NUM> in accordance with whether needle extend button <NUM>-<NUM> or needle retract button <NUM>-<NUM> is depressed.

In the orientation shown in <FIG>, depressing needle extend button <NUM>-<NUM> generates a user output signal that initiates a clockwise rotation of drive gear <NUM>-<NUM>, which in turn results in a counterclockwise rotation of driven gear <NUM>-<NUM> and a linear displacement of drive piston <NUM> in the sequence depicted in <FIG>, wherein <FIG> depicts a fully retracted position of drive piston <NUM>, driven piston <NUM>, and disposable biopsy needle assembly <NUM>; <FIG> depicts an intermediate position of drive piston <NUM>, driven piston <NUM>, and disposable biopsy needle assembly <NUM>; and <FIG> depicts a fully extended position of drive piston <NUM>, driven piston <NUM>, and disposable biopsy needle assembly <NUM>.

Accordingly, as depicted in <FIG>, a full extension of disposable biopsy needle assembly <NUM> is achieved by a one-quarter rotation of driven gear <NUM>-<NUM>. Sensor circuit <NUM>-<NUM> supplies a sensor output signal to microcontroller <NUM>-<NUM>, which in turn processes the sensor output signal to maintain a range of motion driven gear <NUM>-<NUM> in the one-quarter rotation range depicted in <FIG> and <FIG>. In other words, the sensor output signal of sensor circuit <NUM>-<NUM> facilitates a stopping of the rotation of driven gear <NUM>-<NUM> after driven gear <NUM>-<NUM> has displaced drive piston <NUM> by a first linear distance, as determined by monitoring the rotation of driven gear <NUM>-<NUM>. The displacement of drive piston <NUM> by the first linear distance results in a displacement of the driven piston <NUM> by a second linear distance, with the second linear distance being greater than the first linear distance. In turn, the displacement of driven piston <NUM> by the second linear distance also displaces elongate biopsy member <NUM> of disposable biopsy needle assembly <NUM> by the second linear distance.

Alternatively, or in addition, to the use of sensor circuit <NUM>-<NUM> in controlling the range of rotation of driven gear <NUM>-<NUM>, mechanical stops <NUM>-<NUM> and <NUM>-<NUM>, having respective stop surfaces, may be provided in the interior of handle housing <NUM>, so as to be engaged by a protrusion <NUM>, e.g., a rubber bumper, that extends from the side of driven gear <NUM>-<NUM>, wherein mechanical stops <NUM>-<NUM> and <NUM>-<NUM> are positioned to define a physical limit to the amount of rotation that driven gear <NUM>-<NUM> is permitted to rotate. At least one mechanical stop may be used to limit a rotation of driven gear <NUM>-<NUM> to a rotational range of less than <NUM> degrees, and in the present option, two mechanical stops <NUM>-<NUM> and <NUM>-<NUM> are used to physically limit the rotation of driven gear <NUM>-<NUM>, e.g., to a range of one-quarter rotation.

In the embodiments described above, hydraulic drive assembly <NUM> is implemented as a permanent component of driver assembly <NUM>. However, as an alternative implementation of the present invention, it is contemplated that hydraulic drive assembly <NUM> may itself be disposable, and/or may be incorporated into disposable biopsy needle assembly <NUM>.

The invention relates to a biopsy device including a chamber housing having a proximal chamber, a transition chamber, and a distal chamber that form a continuous passage in the chamber housing. The chamber housing may have a longitudinal axis along which the proximal chamber, the transition chamber, and the distal chamber are arranged. The proximal chamber has a first cylindrical side wall that has a first proximal end and a first distal end. The transition chamber may have a frustoconical side wall that has a base end and a narrowed end. The distal chamber may have a second cylindrical side wall that has a second proximal end and a second distal end. The base end of the frustoconical side wall is joined to the first distal end of the first cylindrical side wall and the narrowed end of the frustoconical side wall is joined to the second proximal end of the second cylindrical side wall. A drive piston is located in the proximal chamber. A drive source is connected to the drive piston. The drive source is configured to move the drive piston in the proximal chamber along the longitudinal axis. A driven piston is located in the distal chamber, the driven piston configured to move in the distal chamber along the longitudinal axis. A cavity is defined in the chamber housing between the drive piston and the driven piston. A hydraulic fluid of a fixed quantity fills the cavity between the drive piston and the driven piston. An elongate biopsy member is connected to the driven piston. Due to the configuration of the proximal chamber, transition chamber and distal chamber, a displacement of the drive piston results in an amplified displacement of the driven piston.

The drive piston may have a first proximal end portion and a first distal end portion. The first distal end portion of the drive piston may have a piston head that faces the hydraulic fluid.

The drive source may include a motor having a rotatable shaft. A drive gear is attached to the rotatable shaft. A driven gear may be engaged with the drive gear. The driven gear is configured to rotate about a first rotational axis. The first rotational axis of the driven gear may be oriented to be substantially orthogonal to the longitudinal axis. The longitudinal axis may intersect the first rotational axis. A drive link member may be configured to couple the driven gear to the first proximal end portion of the drive piston.

The drive link member has a first end portion and a second end portion spaced apart from the first end portion. The first end portion of the drive link member may be rotatably coupled to the driven gear at a second rotational axis radially offset by an offset distance from the first rotational axis. The second end portion of the drive link member may be rotatably coupled to the first proximal end portion of the drive piston at a pivot axis at the first proximal end portion of the drive piston. The pivot axis may be oriented to be substantially orthogonal to the longitudinal axis. The longitudinal axis may intersect the pivot axis.

In any of the embodiments, the biopsy device may further include a handle housing configured to contain the chamber housing and the drive source, and wherein the driven piston may have a second proximal end portion and a second distal end portion. The second proximal end portion of the driven piston may have a piston tail that faces the hydraulic fluid in an opposed relationship with the piston head of the drive piston. The second distal end portion of the driven piston may include a needle mount interface configured to releasably connect to the elongate biopsy member. The elongate biopsy member is configured to longitudinally extend from the needle mount interface.

The driven gear may include a mechanical stop that extends from a side surface of the driven gear. The mechanical stop may be configured to engage a stop surface in the handle housing to limit a rotation of the driven gear to a rotational range of less than <NUM> degrees.

The biopsy device may further includes a user interface circuit configured to receive a user input and generate a user output signal. A sensor circuit may be configured to sense a rotation of the driven gear and generate a sensor output signal. A motor interface circuit may be configured to supply electrical power to the motor. A microcontroller may be in electrical communication with each of the user interface circuit, the sensor circuit, and the motor interface circuit. The microcontroller may be configured to execute program instructions to process each of the user output signal and the sensor output signal, and to supply a motor control signal to the motor interface circuit to control operation of the motor.

The user interface circuit may be configured such that the user output signal may initiate a rotation of the driven gear and the sensor output signal may facilitate a stopping of the rotation of the driven gear after the driven gear has displaced the drive piston by a first linear distance.

The user interface circuit may be configured such that the displacement of the drive piston by the first linear distance results in a displacement of the driven piston by a second linear distance. The second linear distance may be greater than the first linear distance.

Claim 1:
A biopsy device (<NUM>), comprising:
a chamber housing (<NUM>) having a proximal chamber (<NUM>), a transition chamber (<NUM>), and a distal chamber (<NUM>) that form a continuous passage in the chamber housing (<NUM>), and having a longitudinal axis (<NUM>) along which the proximal chamber (<NUM>), the transition chamber (<NUM>), and the distal chamber (<NUM>) are arranged,
the proximal chamber (<NUM>) having a first cylindrical side wall (<NUM>-<NUM>) that has a first proximal end (<NUM>-<NUM>) and a first distal end (<NUM>-<NUM>), the transition chamber (<NUM>) having a frustoconical side wall (<NUM>-<NUM>) that has a base end (<NUM>-<NUM>) and a narrowed end (<NUM>-<NUM>), and the distal chamber (<NUM>) having a second cylindrical side wall (<NUM>-<NUM>) that has a second proximal end (<NUM>-<NUM>) and a second distal end (<NUM>-<NUM>), the base end (<NUM>-<NUM>) of the frustoconical side wall (<NUM>-<NUM>) being joined to the first distal end (<NUM>-<NUM>) of the first cylindrical side wall (<NUM>-<NUM>) and the narrowed end (<NUM>-<NUM>) of the frustoconical side wall (<NUM>-<NUM>) being joined to the second proximal end (<NUM>-<NUM>) of the second cylindrical side wall (<NUM>-<NUM>), such that the first cylindrical side wall (<NUM>-<NUM>), the frustoconical side wall (<NUM>-<NUM>), and the second cylindrical side wall (<NUM>-<NUM>) form a continuous interior surface of the chamber housing;
a drive piston (<NUM>) located in the proximal chamber (<NUM>);
a drive source connected to the drive piston (<NUM>), the drive source configured to move the drive piston (<NUM>) in the proximal chamber (<NUM>) along the longitudinal axis (<NUM>);
a driven piston (<NUM>) located in the distal chamber (<NUM>), the driven piston (<NUM>) configured to move in the distal chamber (<NUM>) along the longitudinal axis (<NUM>);
a cavity (<NUM>) defined in the chamber housing (<NUM>) between the drive piston (<NUM>) and the driven piston (<NUM>);
a hydraulic fluid of a fixed quantity that fills the cavity (<NUM>) between the drive piston (<NUM>) and the driven piston (<NUM>), forming a hydraulic connection between the drive piston (<NUM>) and the driven piston (<NUM>), such that a displacement of the drive piston (<NUM>) along the longitudinal axis (<NUM>) results in an amplified displacement of the driven piston (<NUM>) along the longitudinal axis (<NUM>); and
an elongate biopsy member (<NUM>) connected to the driven piston (<NUM>).