Patent Description:
Biopsy samples have been obtained in a variety of ways in various medical procedures including open and percutaneous methods using a variety of devices. For instance, some biopsy devices may be fully operable by a user using a single hand, and with a single insertion, to capture one or more biopsy samples from a patient. In addition, some biopsy devices may be tethered to a vacuum module and/or control module, such as for communication of fluids (e.g., pressurized air, saline, atmospheric air, vacuum, etc.), for communication of power, and/or for communication of commands and the like. Other biopsy devices may be fully or at least partially operable without being tethered or otherwise connected with another device.

One technique for collecting a breast biopsy is to use a core needle biopsy device. One such device is the MAX-CORE disposable core biopsy instrument manufactured by Bard Biopsy Systems. Core needle biopsy devices frequently use a sharp, solid piercer equipped with a lateral tissue receiving notch positioned adjacent to the distal end of the piercer. When tissue is received within the notch, an elongate hollow cutting sheath is translated over the notch to sever a tissue sample. The severed tissue sample is then stored within the notch until both the piercer and the cutting sheath are removed from the patient. Thus, in core-needle biopsy devices, only one tissue sample can be collected per insertion of the piercer and cutting sheath.

Another technique for conducting a breast biopsy is to conduct a breast biopsy using a vacuum-assisted breast biopsy device. A current textbook in this area is "<NPL>.

In contrast to core needle breast biopsy procedures, state of the art vacuum-assisted breast biopsy devices permit the probe to remove multiple samples without requiring the probe be removed from the breast after every sample is collected. For instance, in a vacuum assisted breast biopsy device, a hollow needle is used to penetrate tissue. The hollow needle includes a lateral aperture adjacent to a sharp distal tip. A hollow cutter is disposed within the hollow needle and is moved axially relative to the lateral aperture of the needle to sever tissue samples. Once a tissue sample is severed by the hollow cutter, the tissue sample is transported axially though the cutter and collected in a tissue collection feature.

Examples of vacuum assisted biopsy devices and biopsy system components are disclosed in <CIT>, entitled "Method and Apparatus for Automated Biopsy and Collection of Soft Tissue," issued June <NUM>, <NUM>; <CIT>, entitled "Control Apparatus for an Automated Surgical Biopsy Device," issued July <NUM>, <NUM>; <CIT>, entitled "Fluid Collection Apparatus for a Surgical Device," issued December <NUM>, <NUM>; <CIT>, entitled "Method for Using a Surgical Biopsy System with Remote Control for Selecting an Operational Mode," issued August <NUM>, <NUM>; <CIT>, entitled "Surgical Biopsy System with Remote Control for Selecting an Operational Mode," issued June <NUM>, <NUM>; <CIT>, entitled "Remote Thumbwheel for a Surgical Biopsy Device," issued October <NUM>, <NUM>; <CIT>, entitled "Clutch and Valving System for Tetherless Biopsy Device," issued December <NUM>, <NUM>; <CIT>, entitled "Surgical Biopsy System with Remote Control for Selecting an Operational Mode," issued March <NUM>, <NUM>; <CIT>, entitled "Vacuum Timing Algorithm for Biopsy Device," issued May <NUM>, <NUM>; <CIT>, entitled "Tissue Biopsy Device with Rotatably Linked Thumbwheel and Tissue Sample Holder," issued December <NUM>, <NUM>; <CIT>, entitled "Biopsy Sample Storage," issued February <NUM>, <NUM>; <CIT>, entitled "Tetherless Biopsy Device with Reusable Portion," issued on June <NUM>, <NUM>; <CIT>, entitled "Biopsy Device with Discrete Tissue Chambers," issued on April <NUM>, <NUM>; <CIT>, entitled "Biopsy Device with Motorized Needle Firing," issued October <NUM>, <NUM>; and <CIT>, entitled "Biopsy Device Tissue Sample Holder with Bulk Chamber and Pathology Chamber," issued May <NUM>, <NUM>.

Additional examples of vacuum assisted biopsy devices and biopsy system components are disclosed in <CIT>, entitled "Biopsy Apparatus and Method," published April <NUM>, <NUM> and now abandoned; <CIT>, entitled "Graphical User Interface for Biopsy System Control Module," published May <NUM>, <NUM>, now abandoned; <CIT>, entitled "Hand Actuated Tetherless Biopsy Device with Pistol Grip," published June <NUM>, <NUM>, now abandoned; <CIT>, entitled "Biopsy Device with Central Thumbwheel," published June <NUM>, <NUM>, now abandoned; and <CIT>, entitled "Control for Biopsy Device," published December <NUM>, <NUM>.

Exemplary core needle biopsy devices are disclosed in <CIT>, entitled "Needle Core Biopsy Instrument with Durable or Disposable Cannula Assembly," issued on October <NUM>, <NUM>; <CIT>, entitled "Needle Core Biopsy Device," issued on October <NUM>, <NUM>; <CIT>, entitled "Needle Core Biopsy Device," issued on October <NUM>, <NUM>; and <CIT>, entitled "Needle Core Biopsy Instrument," issued on April <NUM>, <NUM>.

Document <CIT> describes a biopsy apparatus that includes a biopsy probe having a biopsy cannula and a sample basket arranged coaxially about a longitudinal axis. The sample basket is movably disposed relative to the biopsy cannula along the longitudinal axis from a tissue harvesting position to a tissue sample retrieval region.

Document <CIT> describes a tissue sampling device for retrieving one or more tissue samples from a patient that is either handheld or mounted to a moveable carriage and advanced so that the needle tip is introduced into the patient.

Document <CIT> describes a biopsy device for harvesting at least one tissue sample from a body of a living being that comprises a hollow needle with an end portion adapted to be introduced into the body, and a cutting mechanism for severing the tissue sample.

Document <CIT> describes a single-insertion, multiple sampling biopsy device.

While the specification concludes with claims which particularly point out and distinctly claim the invention, it is believed the present invention will be better understood from the following description of certain examples taken in conjunction with the accompanying drawings, in which like reference numerals identify the same elements. In the drawings some components or portions of components are shown in phantom as depicted by broken lines.

The invention is defined by the appended claims solely.

Biopsy devices may be used to collect tissue samples in a variety of ways. For example, in some instances tissue samples are collected into a single tissue basket such that all tissue samples collected during a given biopsy procedure are deposited into the single tissue sample basket. In some other instances, tissue samples are collected into a tissue sample holder having separate compartments for each collected tissue sample. Such a multicompartment tissue sample holder may additionally include trays or strips that individually hold each tissue sample separately from the other tissue samples. Such trays or strips may be removable or otherwise separable from the tissue sample holder at the conclusion of a biopsy procedure.

Regardless of the structure in which the tissue samples are stored, tissue samples may be collected using biopsy devices under the guidance of various imaging modalities such as ultrasound image guidance, stereotactic (X-ray) guidance, MRI guidance, Positron Emission Mammography ("PEM" guidance), Breast-Specific Gamma Imaging ("BSGI") guidance, or otherwise. Each procedure has its own methodology based on the form of imaging guidance used. The following text briefly describes ultrasound image guided biopsy procedures, stereotactic guided biopsy procedures and MRI guided biopsy procedures.

In an ultrasound image guided breast biopsy procedure, the operator may position an ultrasound transducer on the patient's breast and maneuver the transducer while viewing an ultrasound image display screen to locate suspicious tissue in the patient's breast. Once the operator locates the suspicious tissue, the operator may anesthetize the target region of the breast. Once the breast has been anesthetized, the operator may create an initial incision using a scalpel at a location on the exterior of the breast offset from the transducer. A needle of a breast biopsy probe disposed coaxially within an introducer cannula is then inserted into the breast through the initial incision. The operator continues to hold the ultrasound transducer with one hand while maneuvering the biopsy probe with the other hand. While viewing the ultrasound image on the display screen, the operator guides the needle to a position adjacent to the suspicious tissue. A cutter within the needle of the probe is used to remove tissue which is then conveyed either to a manual pick-up location on the breast biopsy device or to a tissue sample chamber. The needle of the breast biopsy device is then removed, leaving the introducer cannula disposed within the breast. The introducer cannula may then be used to introduce a biopsy marker cannula for deploying a biopsy site marker at the biopsy site. Once a marker has been deployed at the biopsy site, the biopsy marker cannula and the introducer cannula are both removed from the breast and the incision is closed using a medically acceptable way to close breaks in the skin.

In a stereotactic image guided breast biopsy procedure, the patient is first positioned relative to x-ray equipment, which includes a breast localization assembly. In some procedures, the patient is oriented in a prone position, with the patient lying face down on a procedure table with at least one breast hanging pendulously through an aperture in the procedure table. The breast is then compressed between a compression paddle and an x-ray receptor of a localization assembly that is positioned under the procedure table. A breast biopsy device is positioned on an automatic guide device in front of the compression paddle and between the breast and an x-ray source. Once positioning of the patient and localization of the breast are complete, a scout image is acquired with the x-ray receptor in a zero-degree angular position (i.e., the x-rays are emitted along an axis normal relative to the x-ray receptor). If the scout image indicates that the patient has been positioned in a desired position, the procedure may proceed with the acquisition of stereotactic image pairs. Stereotactic image pairs are acquired by orienting the x-ray source at various complementary angular positions relative to the x-ray receptor (e.g., +<NUM>° and -<NUM>°), with at least one x-ray image acquired at each position.

Further in the stereotactic image guided breast biopsy procedure, once a suitable stereotactic image pair is acquired, an operator may identify a target site where biopsy sampling is desired by examining the stereotactic image pair. The target site is marked on each stereotactic image and a precise location of the target site on a Cartesian coordinate system is computed using an image processing module. The computed location of the target site is then communicated to the automatic guide device. The automatic guide device is responsive to this information to position the breast biopsy probe into a position that aligns with the target site. With the breast biopsy device positioned, an operator may then fire a needle of the biopsy probe into the breast of the patient, thereby positioning the needle at the target site. A cutter within the needle of the probe is used to remove tissue, which is then conveyed either to a manual pick-up location on the breast biopsy device or to a tissue sample chamber. After the biopsy tissue is removed, a biopsy marker cannula is inserted into the needle and is used to deploy a biopsy site marker at the biopsy site. Once a marker has been deployed at the biopsy site, the needle is removed from the breast and the incision is closed using a medically acceptable way to close breaks in the skin.

In an MRI guided breast biopsy procedure, after the patient is properly positioned on the table and a targeting device (e.g., a grid and cube combination or a pillar, post and cradle support combination) has been deployed and used, a baseline MRI image is taken to verify the target location. After that, a scalpel is used to incise the skin of the breast. Next, an assembly, formed by an obturator disposed in a sleeve, is inserted through the incision to penetrate the breast tissue under the skin. In some acceptable surgical techniques, the obturator is removed and an imaging rod is inserted into the sleeve in place of the obturator. An imaging rod is defined simply as an appropriately shaped rod that includes a feature that is detectable by an imaging technique being used for the biopsy procedure. The MRI image of the imaging rod is used to locate the site to which the sleeve/obturator assembly has penetrated. In some other acceptable surgical techniques, the obturator cooperates with the breast tissue to provide a visually observable artifact in an MRI image. With both of these techniques, after the location within the breast where the biopsy is to be taken is confirmed, the obturator or the imaging rod is removed.

Further in the MRI guided breast biopsy procedure, after the obturator or imaging rod has been removed, it is replaced in the sleeve with the needle of a breast biopsy probe. A cutter within the needle of the probe is used to remove tissue, which is then conveyed either to a manual pick up location on the breast biopsy device or to a breast biopsy device sample chamber. After the biopsy tissue is removed, a biopsy marker cannula is inserted into the needle and is used to deploy a biopsy site marker at the biopsy site. The needle is then removed from the sleeve. Optionally, the imaging rod or the obturator is put back into the breast for reimaging of the biopsy site. Then the imaging rod or obturator and the sleeve are removed.

Vacuum assisted biopsy devices and core needle biopsy devices both may have various advantages over the other, depending on context. For instance, one advantage of vacuum assisted biopsy devices is that vacuum assistance permits removal of multiple tissue samples using a single insertion. However, while core needle biopsy devices lack this feature, use of core needle biopsy devices may still be desirable. For instance, core needle biopsy devices are generally capable of having smaller needles relative to core needle biopsy devices, thereby reducing patient anxiety and increasing the capacity of the needle to penetrate a lesion. Therefore, in some instances it may be desirable to incorporate the feature of multiple sample removal of a vacuum assisted biopsy device into a core needle biopsy device to achieve the benefits present in both styles of biopsy device.

A desirable feature of the device described herein, which is a core needle biopsy device is that the device allows for single insertion with multiple samples being obtained whilst using a core needle type device. Currently, it is believed that only vacuum assisted biopsy devices have this ability.

<FIG> shows an exemplary core needle biopsy device (<NUM>) for use in a breast biopsy procedure. Core needle biopsy device (<NUM>) of the present example comprises a body (<NUM>) and a needle assembly (<NUM>) extending distally from body (<NUM>). Body (<NUM>) includes an outer housing (<NUM>) and an actuation member (<NUM>) disposed on outer housing (<NUM>). As will be describe in greater detail below, outer housing (<NUM>) encloses various components of biopsy device (<NUM>), which are used to drive needle assembly (<NUM>) through a cutting cycle and a tissue acquisition cycle. To this end, outer housing (<NUM>) of the present example is sized and shaped for grasping by an operator using a single hand. Although not shown, it should be understood that in some examples outer housing (<NUM>) may comprise multiple parts such that each part interconnects to form outer housing (<NUM>).

<FIG> and <FIG> show needle assembly (<NUM>) in greater detail. As can be seen in <FIG>, needle assembly (<NUM>) comprises an elongate piercer (<NUM>) and an elongate cutter (<NUM>). As will be described in greater detail below, piercer (<NUM>) is generally movable relative to cutter (<NUM>) to pierce tissue and collect tissue samples, while cutter is generally movable relative to piercer (<NUM>) to sever tissue samples. Piercer (<NUM>) comprises a generally cylindrical rod having a sharp distal tip (<NUM>) and a notch (<NUM>) disposed adjacent to distal tip (<NUM>). As will be described in greater detail below, distal tip (<NUM>) is generally configured to penetrate tissue of a patient. As will also be described in greater detail below, notch (<NUM>) is generally configured to receive tissue therein such that a tissue sample may be collected within notch (<NUM>) after the tissue sample is severed by cutter (<NUM>).

Later in this application specific means and ways to move needle assembly (<NUM>) forward and backwards within core needle biopsy device (<NUM>) are described. At this point Applicants wish to point out that although they have included specific ways and means to move needle assembly (<NUM>) forwards and backwards, they believe, without intending to be bound thereby, that there are many alternative way to move needle assembly (<NUM>) backwards and forwards and these alternative ways should be known to people of ordinary skill in the art of designing biopsy devices.

An end portion (<NUM>) is disposed on the proximal end of piercer (<NUM>). End portion (<NUM>) of the present example is overmolded onto the proximal end of piercer (<NUM>) and is generally configured to enhance the manipulability of piercer (<NUM>). In particular, end portion (<NUM>) comprises a receiving feature (<NUM>) in the form of a lateral notch. Receiving feature (<NUM>) is configured to receive a portion of a piercer drive assembly (<NUM>). As will be described in greater detail below, this permits piercer drive assembly (<NUM>) to drive movement of piercer (<NUM>) through a predetermined sequence of movement.

Cutter (<NUM>) comprises a generally hollow cylindrical tube that is configured to receive piercer (<NUM>) therein. Cutter (<NUM>) comprises an open distal end (<NUM>), a cannula portion (<NUM>) and an end portion (<NUM>). Open distal end (<NUM>) is configured to permit at least a portion of piercer (<NUM>) to protrude from cutter (<NUM>) when piercer (<NUM>) is moved relative to cutter (<NUM>). As will be described in greater detail below, this configuration permits needle assembly (<NUM>) to move through the cutting cycle and the tissue acquisition cycle by permitting notch (<NUM>) of piercer (<NUM>) to move relative to distal end (<NUM>) of cutter (<NUM>).

Open distal end (<NUM>) of the present example includes a tapered edge (<NUM>). Tapered edge (<NUM>) is generally configured to slice through tissue to separate tissue samples when cutter (<NUM>) is moved relative to notch (<NUM>) of piercer (<NUM>). Thus, it should be understood that tapered edge (<NUM>) is generally configured to act a blade. Although the present example is described and shown as using a tapered configuration, it should be understood that in other examples various alternative configurations can be used. For instance, in some examples tapered edge (<NUM>) includes a plurality of serrations in addition or in alternative to the taper shown. In still other examples, tapered edge (<NUM>) can include any other additional or alternative cutting surface as will be apparent to those of ordinary skill in the art in view of the teachings herein.

Cannula portion (<NUM>) of cutter (<NUM>) extends proximally from distal end (<NUM>) through end portion (<NUM>) such that piercer (<NUM>) can be received with the proximal end of cutter (<NUM>). Unlike end portion (<NUM>) of piercer (<NUM>), end portion (<NUM>) of cutter (<NUM>) is generally elongate such that at least a portion of end portion (<NUM>) extends distally relative to outer housing (<NUM>). As will be described in greater detail below, this distal extension relative to outer housing (<NUM>) permits a portion of end portion (<NUM>) to be accessible to an operator for tissue sample collection purposes.

End portion (<NUM>) of cutter (<NUM>) comprises a receiving feature (<NUM>) and a tissue collection feature (<NUM>). As with receiving feature (<NUM>) of piercer (<NUM>), receiving feature (<NUM>) of end portion (<NUM>) comprises a lateral slot or other receiving feature that is configured to receive at least a portion of a cutter drive assembly (<NUM>). As will be described in greater detail below, receiving feature (<NUM>) is configured to receive at least a portion of cutter drive assembly (<NUM>) to permit cutter drive assembly (<NUM>) to move cutter (<NUM>) through a predetermined sequence of movement.

Tissue collection feature (<NUM>) is disposed distally relative to receiving feature (<NUM>). Tissue collection feature (<NUM>) generally defines an elongate notch that is open to cannula portion (<NUM>) of cutter (<NUM>). Correspondingly, cannula portion (<NUM>) includes a cutout portion (<NUM>) that is adjacent to tissue collection feature (<NUM>). Accordingly, it should be understood that tissue collection feature (<NUM>) is in communication with the hollow interior, or a lumen, defined by cannula portion (<NUM>). As will be described in greater detail below, this relationship between tissue collection feature (<NUM>) and cannula portion (<NUM>) permits an operator to remove tissue samples from cutter (<NUM>) as they are collected by piercer (<NUM>).

<FIG> shows piercer (<NUM>) disposed within cutter (<NUM>). As can be seen, cutter (<NUM>) is generally configured to receive piercer (<NUM>) such that piercer (<NUM>) is coaxial with cutter (<NUM>). In addition, piercer (<NUM>) is generally movable relative to open distal end (<NUM>) of cutter (<NUM>). It should be understood that in some circumstances piercer (<NUM>) moves relative to cutter (<NUM>), while cutter (<NUM>) remains stationary. In other circumstances, cutter (<NUM>) moves relative to piercer (<NUM>), while piercer (<NUM>) remains stationary. In either case, it should be understood that piercer (<NUM>) and cutter (<NUM>) are generally configured such that notch (<NUM>) of piercer (<NUM>) moves into and out of cutter (<NUM>) such that notch (<NUM>) can be disposed distally or proximally relative to open distal end (<NUM>) of cutter (<NUM>). As will be described in greater detail below, this configuration permits piercer (<NUM>) and cutter (<NUM>) to operate cooperatively to pierce tissue, cut a tissue sample, and retract the tissue sample for collection by an operator via tissue collection feature (<NUM>).

<FIG> and <FIG> show the internal components of body (<NUM>) of biopsy device (<NUM>) with outer housing (<NUM>) removed. As can be seen, inside outer housing (<NUM>), body (<NUM>) includes a drive assembly (<NUM>). Drive assembly (<NUM>) is generally configured to engage needle assembly (<NUM>) to drive piercer (<NUM>) and cutter (<NUM>) through a predetermined sequence of movements to thereby pierce tissue and acquire a plurality of tissue samples with a single insertion of needle assembly (<NUM>) into a patient. Although not shown, it should be understood that outer housing (<NUM>) defines various internal geometries that support or otherwise engage drive assembly (<NUM>). As will be understood, such internal geometries are used to provide relative movement of various components of drive assembly (<NUM>) relative to other components of drive assembly (<NUM>) and/or outer housing (<NUM>).

Drive assembly (<NUM>) comprises a needle cocking assembly (<NUM>), a cutter drive assembly (<NUM>), a piercer drive assembly (<NUM>), and a release assembly (<NUM>). Generally, and as will be described in greater detail below, needle cocking assembly (<NUM>) engages cutter drive assembly (<NUM>) and piercer drive assembly (<NUM>) to cock cutter drive assembly (<NUM>) and piercer drive assembly (<NUM>), which correspondingly cock cutter (<NUM>) and piercer (<NUM>). Release assembly (<NUM>) also engages cutter drive assembly (<NUM>) and piercer drive assembly (<NUM>) to selectively release and fire cutter drive assembly (<NUM>) and piercer drive assembly (<NUM>) to thereby selectively release and fire cutter (<NUM>) and piercer (<NUM>).

Needle cocking assembly (<NUM>) is best seen in <FIG>. As can be seen, needle cocking assembly (<NUM>) comprises a lead screw (<NUM>), a carriage nut (<NUM>), a drive member (<NUM>), and a motor assembly (<NUM>). Lead screw (<NUM>) is best seen in <FIG>. As can be seen lead screw (<NUM>) is generally an elongate multi-threaded rod. Lead screw (<NUM>) comprises a distal end (<NUM>), first threaded portion (<NUM>), a slide stop portion (<NUM>), a non-threaded portion (<NUM>), a keyway (<NUM>), a second threaded portion (<NUM>), and a proximal end (<NUM>).

Distal end (<NUM>) of lead screw (<NUM>) generally comprises a cylindrical shape extending distally from first threaded portion (<NUM>). Distal end (<NUM>) is configured to be received by at least a portion of outer housing (<NUM>) or another intermediate connecting member, such as a bearing, to permit lead screw (<NUM>) to rotate about a fixed axis. Thus, it should be understood that distal end (<NUM>) generally acts as a boss or locating feature to permit rotation of lead screw (<NUM>).

First threaded portion (<NUM>) is disposed proximally of distal end (<NUM>). First threaded portion (<NUM>) includes threads (<NUM>) which have a relatively fine pitch. As will be described in greater detail below, threads (<NUM>) are generally configured to engage a portion of cutter drive assembly (<NUM>) to convert rotational motion of lead screw (<NUM>) into translation of at least a portion of cutter drive assembly (<NUM>). This conversion of motion generally results in proximal and distal translation of at least a portion of cutter drive assembly (<NUM>), which results in cocking of cutter drive assembly (<NUM>).

Slide stop portion (<NUM>) is disposed proximally of first threaded portion (<NUM>) and distally of keyway (<NUM>), second threaded portion (<NUM>) and proximal end (<NUM>). Slide stop portion (<NUM>) comprises a generally cylindrical shape. The diameter of slide stop portion (<NUM>) generally corresponds to the major pitch diameter of first threaded portion (<NUM>). As will be described in greater detail below, these size and shape characteristics of slide stop portion (<NUM>) permit slide stop portion (<NUM>) to provide coaxial support of at least a portion of cutter drive assembly (<NUM>) as cutter drive assembly (<NUM>) moves relative to lead screw (<NUM>).

The diameter of slide stop portion (<NUM>) is also generally greater than the diameter of non-threaded portion (<NUM>) of lead screw (<NUM>). As will be understood, this differential in diameter between slide stop portion (<NUM>) and non-threaded portion (<NUM>) permits slide stop portion (<NUM>) to act as a mechanical stop feature. As will be described in greater detail below, this mechanical stop feature is configured to limit distal translation of carriage nut (<NUM>) as carriage nut (<NUM>) moves along lead screw (<NUM>).

Between slide stop portion (<NUM>) and first threaded portion (<NUM>), lead screw (<NUM>) defines an indented portion (<NUM>). As will be described in greater detail below, indented portion (<NUM>) is generally configured to permit a portion of cutter drive assembly (<NUM>) to "free-wheel" when cutter drive assembly (<NUM>) is disposed in axial alignment with indented portion (<NUM>). It should be understood that the term "free-wheel" used herein refers to the ability of lead screw (<NUM>) to continue to rotate without additional proximal translation of cutter drive assembly (<NUM>) and without binging between lead screw (<NUM>) and at least a portion of cutter drive assembly (<NUM>). It should be understood that during free-wheeling, at least a portion of cutter drive assembly (<NUM>) is generally disengaged from first threaded portion (<NUM>) of lead screw (<NUM>). However, it should be understood that the length of indented portion (<NUM>) is sufficiently limited such that when rotation of lead screw (<NUM>) is reversed, at least a portion of cutter drive assembly (<NUM>) reengages with first threaded portion (<NUM>) of lead screw (<NUM>). Further details of the relationship between indented portion (<NUM>), first threaded portion (<NUM>) and cutter drive assembly (<NUM>) will be described in greater detail below.

As shown in <FIG>, non-threaded portion (<NUM>) is proximally adjacent to slide stop portion (<NUM>). Non-threaded portion (<NUM>) is also distally adjacent to second threaded portion (<NUM>) and is disposed distally of proximal end (<NUM>). Non-threaded portion (<NUM>) is generally of a cylindrical shape without threads or other features. However, as can be seen in <FIG>, keyway (<NUM>) extends through non-threaded portion (<NUM>) and through second threaded portion (<NUM>). As previously described above with respect to slide stop portion (<NUM>), non-threaded portion (<NUM>) has a diameter that is generally less than the diameter defined by slide stop portion (<NUM>). As also described above, this differential in diameter between non-threaded portion (<NUM>) and slide stop portion (<NUM>) permits non-threaded portion (<NUM>) to provide a mechanical stop feature for carriage nut (<NUM>), as will be described in greater detail below.

Second threaded portion (<NUM>) is disposed between non-threaded portion (<NUM>) and proximal end (<NUM>), with non-threaded portion (<NUM>) distal of second threaded portion (<NUM>) and proximal end (<NUM>) proximal of non-threaded portion (<NUM>). Second threaded portion (<NUM>) includes a plurality of relatively course threads (<NUM>). Threads (<NUM>) are generally course relative to threads (<NUM>) of first threaded portion (<NUM>). Thus it should be understood that with both threads (<NUM>, <NUM>) acting to transfer rotary movement into axial translation, threads (<NUM>) of second threaded portion (<NUM>) will generally provide faster translation from the same rotary input relative to threads (<NUM>) of first threaded portion (<NUM>).

Second threaded portion (<NUM>) of the present example is configured to engage at least a portion of piercer drive assembly (<NUM>). As will be described in greater detail below, threads (<NUM>) of second threaded portion (<NUM>) are generally configured to convert rotatory motion of lead screw (<NUM>) into axial translation of at least a portion of piercer drive assembly (<NUM>). This conversion of rotary motion into translation permits piercer drive assembly to translate piercer (<NUM>) for the purpose of tissue collection via tissue collection feature (<NUM>).

In the present example, second threaded portion (<NUM>) and non-threaded portion (<NUM>) are arranged such that non-threaded portion (<NUM>) defines a length. The length of non-threaded portion (<NUM>) is generally just greater than the approximate length of carriage nut (<NUM>). As will be understood, the length of non-threaded portion permits carriage nut (<NUM>) to be axially translated by piercer drive assembly (<NUM>) until being stopped by slide stop portion (<NUM>). Once translation is ceased by slide stop portion (<NUM>), however, non-threaded portion (<NUM>) permits lead screw (<NUM>) to "free-wheel" relative to piercer drive assembly (<NUM>). It should be understood that the term "free-wheel" used herein refers to the ability of lead screw (<NUM>) to continue to rotate without additional translation of piercer drive assembly (<NUM>) and without binding between lead screw (<NUM>) and piercer drive assembly (<NUM>). During free-wheeling, piercer drive assembly (<NUM>) generally disengaged from second threaded portion (<NUM>). However, it should be understood that the length of non-threaded portion remains limited to an extent such that when rotation of lead screw (<NUM>) is reversed, piercer drive assembly (<NUM>) reengages with second threaded portion (<NUM>). Further details of the relationship between non-threaded portion (<NUM>), second threaded portion (<NUM>) and piercer drive assembly (<NUM>) will be described in greater detail below.

Returning to <FIG>, rotation of lead screw (<NUM>) is provided by drive member (<NUM>) and motor assembly (<NUM>). In particular, drive member (<NUM>) of the present example is configured to be fixedly secured to proximal end (<NUM>) of lead screw (<NUM>). Drive member (<NUM>) includes a rotary communication feature (<NUM>) which is configured to transmit rotary motion from a rotary communication feature (<NUM>) of motor assembly (<NUM>) to lead screw (<NUM>). In the present example, rotatory communication features (<NUM>, <NUM>) are configured as belt drives such that rotatory motion is communicated via a belt (not shown). It should be understood that although rotary communication features (<NUM>, <NUM>) are shown as using a belt drive, any other suitable rotary communication feature may be used. For instance, in some examples rotary communication features (<NUM>, <NUM>) can include one or more gears with varying gear ratios to communicate rotary motion from motor assembly (<NUM>) to lead screw (<NUM>). Of course, in other examples, rotary communication features (<NUM>, <NUM>) can be omitted entirely such that motor assembly (<NUM>) includes a direct drive that directly communicates rotary motion to lead screw (<NUM>).

As described above, motor assembly (<NUM>) includes a rotary communication feature (<NUM>). Additionally, motor assembly (<NUM>) includes a rotary power source (<NUM>). Rotary power source (<NUM>) of the present example includes an electric motor. In other examples, rotary power source (<NUM>) may include any other suitable power source such as a pneumatic motor, a piezo electric motor, and/or etc..

<FIG> shows carriage nut (<NUM>) in greater detail. As can be seen, carriage nut (<NUM>) comprises a generally cylindrical shape with a bore (<NUM>) extending entirely therethough. Extending inwardly into bore (<NUM>) is a key (<NUM>). Key (<NUM>) extends axially through at least a portion of the length of carriage nut (<NUM>). As will be described in greater detail below, key (<NUM>) is generally configured to engage keyway (<NUM>) of lead screw (<NUM>) such that carriage nut (<NUM>) is generally configured to rotate in conjunction with lead screw (<NUM>).

On the exterior of carriage nut (<NUM>), carriage nut (<NUM>) defines a threaded portion (<NUM>) and a slide portion (<NUM>). Threaded portion (<NUM>) includes a plurality of threads (<NUM>). Threads (<NUM>) generally include a pitch that is relatively fine and generally equivalent to the pitch of threads (<NUM>) of first threaded portion (<NUM>) described above with respect to lead screw (<NUM>). As will be described in greater detail, threads (<NUM>) of threaded portion (<NUM>) are generally configured to engage at least a portion of piercer drive assembly (<NUM>) to move at least a portion of piercer drive assembly (<NUM>) thorough a variety of positions to thereby cock and fire piercer (<NUM>).

Slide portion (<NUM>) defines a generally cylindrical shape having an outer diameter. The outer diameter of slide portion (<NUM>) approximately corresponds to the major diameter of threaded portion (<NUM>). As will be described in greater detail below, this correspondence in diameters permits at least a portion of cutter drive assembly (<NUM>) to freely slide over both slide portion (<NUM>) and threaded portion (<NUM>), while remaining generally coaxial with carriage nut (<NUM>).

Adjacent to the proximal end of carriage nut (<NUM>), slide portion (<NUM>) defines an annular channel (<NUM>). As will be described in greater detail below, annular channel (<NUM>) is configured to receive at least a portion of piercer drive assembly (<NUM>) to axially secure at least a portion of piercer drive assembly (<NUM>) to carriage nut (<NUM>). However, as will also be described in greater detail below, any portion of cutter drive assembly (<NUM>) axially secured to carriage nut (<NUM>) via cannula channel (<NUM>) is rotatably unsecured such that carriage nut (<NUM>) can rotate relative to piercer drive assembly (<NUM>).

Disposed between slide portion (<NUM>) and threaded portion (<NUM>), carriage nut (<NUM>) defines an indented portion (<NUM>). Indented portion (<NUM>) is defined by an outer diameter that is generally less than the major diameter of threaded portion (<NUM>) and the outer diameter of slide portion (<NUM>). In addition, indented portion (<NUM>) defines a length. As will be described in greater detail below, the length of indented portion (<NUM>) is generally approximately equivalent to at least a portion of piercer drive assembly (<NUM>) to permit a portion of piercer drive assembly (<NUM>) to free-wheel relative to carriage nut (<NUM>).

As will be described in greater detail below, indented portion (<NUM>) is generally configured to permit a portion of piercer drive assembly (<NUM>) to free-wheel when piercer drive assembly (<NUM>) is disposed in axial alignment with indented portion (<NUM>). As similarly discussed above with respect to non-threaded portion (<NUM>) of lead screw (<NUM>), the term "free-wheel" used herein refers to the ability of carriage nut (<NUM>) to continue to rotate without additional proximal translation of piercer drive assembly (<NUM>) and without binging between carriage nut (<NUM>) and at least a portion of piercer drive assembly (<NUM>). It should be understood that during free-wheeling, at least a portion of piercer drive assembly (<NUM>) is generally disengaged from threaded portion (<NUM>) of carriage nut (<NUM>). However, it should be understood that the length of indent portion (<NUM>) is sufficiently limited such that when rotation of carriage nut (<NUM>) is reversed, at least a portion of piercer drive assembly (<NUM>) reengages with threaded portion (<NUM>) of carriage nut (<NUM>). Further details of the relationship between indented portion (<NUM>), threaded portion (<NUM>) and piercer drive assembly (<NUM>) will be described in greater detail below.

<FIG> shows carriage nut (<NUM>) coaxially disposed on lead screw (<NUM>). As can be seen, when carriage nut (<NUM>) is disposed on lead screw (<NUM>), key (<NUM>) extends into keyway (<NUM>) of lead screw (<NUM>). Accordingly, it should be understood that keyway (<NUM>) of lead screw (<NUM>) is configured to engage key (<NUM>) such that rotation of lead screw (<NUM>) results in corresponding rotation of carriage nut (<NUM>). It should be understood that since keyway (<NUM>) extends through both second threaded portion (<NUM>) and non-threaded portion (<NUM>) of lead screw (<NUM>), keyway (<NUM>) is configured to engage key (<NUM>) of carriage nut (<NUM>) as carriage nut (<NUM>) travels axially about second threaded portion (<NUM>) and non-threaded portion (<NUM>) of lead screw (<NUM>).

<FIG> shows cutter actuation assembly (<NUM>) in greater detail. In particular, cutter actuation assembly (<NUM>) comprises a cocking member (<NUM>), an actuation member (<NUM>), and a resilient member (<NUM>). Cocking member (<NUM>) comprises a stop portion (<NUM>), a slide portion (<NUM>), and a bore (<NUM>) extending axially though cocking member (<NUM>). Stop portion (<NUM>) is generally configured to act as a mechanical stop for actuation member (<NUM>). Accordingly, stop portion (<NUM>) forms a shape that is similar to a partially cylindrical flange or another similar feature. As will be described in greater detail below, this mechanical stop feature of stop portion (<NUM>) is generally configured to manipulate motion of actuation member (<NUM>) as actuation member (<NUM>) moves cutter (<NUM>) through a predetermined sequence of motion.

Stop portion (<NUM>) further defines an alignment tab (<NUM>) extending upwardly relative to bore (<NUM>). Alignment tab (<NUM>) comprises a generally rectangular or cubic shape. In other examples, alignment tab (<NUM>) may comprise any other suitable shape such as cylindrical, ball-shaped, triangular, and/or etc. Although not shown, it should be understood that alignment tab (<NUM>) is configured to be received within a corresponding channel or track disposed within outer housing (<NUM>) or an intermediate housing (not shown). Such a channel or track is configured to restrict motion of cocking member (<NUM>) to a particular predetermined axial path. Such a channel or track is further configured to prevent rotation of cocking member (<NUM>) relative to lead screw (<NUM>) to thereby permit lead screw (<NUM>) to drive axial motion of cocking member (<NUM>), as will be described in greater detail below.

Slide portion (<NUM>) of cocking member (<NUM>) extends proximally from stop portion (<NUM>). Slide portion (<NUM>) comprises a generally cylindrical outer surface that is configures to receive actuation member (<NUM>). As will be described in greater detail below, actuation member (<NUM>) is generally coaxially slidable on slide portion (<NUM>) to actuate cutter (<NUM>) through a predetermined sequence of motion. However, slide portion (<NUM>) has a diameter that is less than the size or diameter of stop portion (<NUM>). Accordingly, it should be understood that actuation member (<NUM>) is generally coaxially slidable on slide portion (<NUM>) until actuation member (<NUM>) reaches stop portion (<NUM>). At which point, any additional distal sliding relative to slide portion (<NUM>) is ceased by stop portion (<NUM>).

As described above, bore (<NUM>) of cocking member (<NUM>) extends through both stop portion (<NUM>) and slide portion (<NUM>). Bore (<NUM>) defines a plurality of threads (<NUM>) extending inwardly into bore (<NUM>). As best seen in <FIG>, threads (<NUM>) of bore (<NUM>) extend through only the length of bore (<NUM>) corresponding to the length of stop portion (<NUM>). Although threads (<NUM>) of the present example only extend partially though bore (<NUM>), it should be understood that in other examples threads (<NUM>) can extend for the entire length of bore (<NUM>). However, it should be understood that in such examples certain complementary features of lead screw (<NUM>) may require adjustment in length/size to accommodate the additional length of threads (<NUM>).

Bore (<NUM>) is configured to receive at least a portion of lead screw (<NUM>). In particular, bore (<NUM>) is configured to receive first threaded portion (<NUM>), indented portion (<NUM>), and/or slide stop portion (<NUM>) of lead screw (<NUM>) at various stages during the cutting cycle and the tissue acquisition cycle, as will be described in greater detail below. As will be understood, threads (<NUM>) are configured to engage threads (<NUM>) of first threaded portion (<NUM>). Thus, it should be understood that rotation of lead screw (<NUM>) relative to cocking member (<NUM>) will generally result in axial translation of cocking member (<NUM>) relative to lead screw (<NUM>).

As described above, threads (<NUM>) of bore (<NUM>) are generally limited to the length of stop portion (<NUM>). Because a portion of bore (<NUM>) in the present example is un-threaded (e.g., the portion corresponding to slide portion (<NUM>)), it should be understood that bore (<NUM>) can receive at least a portion of slide stop portion (<NUM>) of lead screw (<NUM>). However, because slide stop portion (<NUM>) defines a diameter approximately equivalent to the major diameter of first threaded portion (<NUM>) of lead screw (<NUM>), it should be understood that as cocking member (<NUM>) moves proximally relative to lead screw (<NUM>) such relative motion will only be permitted until threads (<NUM>) reach slide stop portion (<NUM>) of lead screw (<NUM>). Once threads (<NUM>) reach slide stop portion (<NUM>) of lead screw (<NUM>), an interference between the major diameter of threads (<NUM>) and the outer diameter of slide stop portion (<NUM>) will prevent further proximal movement of cocking member (<NUM>). Moreover, threads (<NUM>) at this stage will be adjacent to intended portion (<NUM>) and therefore disengaged with threads (<NUM>) of first threaded portion (<NUM>).

Actuation member (<NUM>) comprises a body (<NUM>), an alignment tab (<NUM>), and an actuation tab (<NUM>). Body (<NUM>) comprises a shape that is generally similar to stop portion (<NUM>) described above with respect to cocking member (<NUM>). Like with stop portion (<NUM>), body (<NUM>) defines a bore (<NUM>) extending through body (<NUM>). Bore (<NUM>) of body (<NUM>) is configured to receive slide portion (<NUM>) of cocking member (<NUM>). Thus, it should be understood that actuation member (<NUM>) is generally coaxially slidable with slide portion (<NUM>) of cocking member (<NUM>).

Alignment tab (<NUM>) extends upwardly from body (<NUM>). Like with alignment tab (<NUM>) of cocking member (<NUM>), alignment tab (<NUM>) of actuation member (<NUM>) is configured to engage a channel or track disposed in outer housing (<NUM>) or an intermediate housing (not shown). As similarly discussed above, this configuration generally permits such a channel or tack to restrict the motion of actuation member (<NUM>) to a predetermined path. However, unlike alignment tab (<NUM>) discussed above, alignment tab (<NUM>) of actuation member (<NUM>) only extends for a relatively small distance from body (<NUM>). Instead of alignment tab (<NUM>) extending for the full extent as seen with alignment tab (<NUM>), a portion of alignment tab (<NUM>) of actuation member (<NUM>) is replaced with a release member (<NUM>). Release member (<NUM>) comprises a generally cylindrical shape. As will be described in greater detail below, release member (<NUM>) is generally configured to be received by release assembly (<NUM>) to temporarily hold actuation member (<NUM>) in a cocked position and then selectively release actuation member (<NUM>) via actuation of release assembly (<NUM>).

Actuation tab (<NUM>) extends downwardly from body (<NUM>). Actuation tab (<NUM>) comprises an upper portion (<NUM>) and a lower portion (<NUM>). Upper portion (<NUM>) comprises a generally rectangular shape. Although not shown, it should be understood that in some examples upper portion (<NUM>) can be configured to be received within a cannel or track of outer housing (<NUM>) or an intermediate internal housing (not shown) thereof. In such examples, upper portion (<NUM>) functions to restrict motion of actuation member (<NUM>) to a predetermined path.

Lower portion (<NUM>) of actuation tab (<NUM>) extends downwardly from upper portion (<NUM>). Lower portion (<NUM>) is generally configured to be received within receiving feature (<NUM>) of cutter (<NUM>). As will be described in greater detail below, when lower portion (<NUM>) is received within receiving feature (<NUM>) of cutter (<NUM>), actuation member (<NUM>) is generally permitted to drive cutter (<NUM>) through a predetermined sequence of movements via lower portion (<NUM>). Although not show, it should be understood that in examples where upper portion (<NUM>) is received within a channel or track of outer housing (<NUM>) or an intermediate internal housing, such a channel or track may include an opening or additional channel to prevent lower portion (<NUM>) to extend through such a channel or track to receiving feature (<NUM>) of cutter (<NUM>).

When cutter drive assembly (<NUM>) is assembled (e.g., as seen in <FIG>), spring (<NUM>) is disposed adjacent to the proximal end of actuation member (<NUM>). In addition, spring (<NUM>) is disposed coaxially around slide portion (<NUM>) of cocking member (<NUM>) and/or coaxially around slide stop portion (<NUM>) of lead screw (<NUM>), depending on the particular stage of operation of drive assembly (<NUM>). As will be described in greater detail below, spring (<NUM>) is generally configured to drive actuation member (<NUM>) distally after actuation member (<NUM>) is released by release assembly (<NUM>). Spring (<NUM>) generally defines an outer diameter that approximately corresponds to the outer diameter of slide portion (<NUM>) of cocking member (<NUM>). Although spring (<NUM>) of the present example is shown as a coil spring, it should be understood that any other suitable resilient member may be used as will be apparent to those of ordinary skill in the art in view of the teachings herein.

<FIG> shows piercer drive assembly (<NUM>) in greater detail. As can be seen, piercer drive assembly (<NUM>) comprises a cocking member (<NUM>), an actuation member (<NUM>), a piercer retraction assembly (<NUM>), and a spring (<NUM>). Cocking member (<NUM>) of piercer drive assembly (<NUM>) is similar to cocking member (<NUM>) of cutter drive assembly (<NUM>). In particular, like with cocking member (<NUM>), cocking member (<NUM>) comprises a stop portion (<NUM>), a slide portion (<NUM>), and a bore (<NUM>) extending axially though cocking member (<NUM>). Stop portion (<NUM>) is generally configured to act as a mechanical stop for actuation member (<NUM>). Accordingly, stop portion (<NUM>) forms a shape that is similar to a partially cylindrical flange or another similar feature. As will be described in greater detail below, this mechanical stop feature of stop portion (<NUM>) is generally configured to manipulate motion of actuation member (<NUM>) as actuation member (<NUM>) moves piercer (<NUM>) through a predetermined sequence of motion.

Stop portion (<NUM>) further defines an alignment tab (<NUM>) extending upwardly relative to bore (<NUM>). Alignment tab (<NUM>) comprises a generally rectangular or cubic shape. In other examples, alignment tab (<NUM>) may comprise any other suitable shape such as cylindrical, ball-shaped, triangular, and/or etc. Although not shown, it should be understood that alignment tab (<NUM>) is configured to be received within a corresponding channel or track disposed within outer housing (<NUM>) or an intermediate housing (not shown). Such a channel or track is configured to restrict motion of cocking member (<NUM>) to a particular predetermined axial path. Such a channel or track is further configured to prevent rotation of cocking member (<NUM>) relative to lead screw (<NUM>) and carriage nut (<NUM>) to thereby permit lead screw (<NUM>) and carriage nut (<NUM>) to drive axial motion of cocking member (<NUM>), as will be described in greater detail below.

As described above, bore (<NUM>) of cocking member (<NUM>) extends through both stop portion (<NUM>) and slide portion (<NUM>). Bore (<NUM>) defines a plurality of threads (<NUM>) extending inwardly into bore (<NUM>). As can best be seen in <FIG>, threads (<NUM>) of bore (<NUM>) extend through only the longitudinal length of bore (<NUM>) corresponding to the length of stop portion (<NUM>). In other examples, threads (<NUM>) can alternatively extend for the entire length of bore (<NUM>). However, it should be understood that in such examples certain complementary features of carriage nut (<NUM>) may require adjustment in length/size to accommodate the additional length of threads (<NUM>).

Bore (<NUM>) is configured to receive at least a portion of carriage nut (<NUM>). In particular, bore (<NUM>) is configured to receive threaded portion (<NUM>), indented portion (<NUM>), and/or slide portion (<NUM>) of carriage nut (<NUM>) at various stages during the cutting cycle and the tissue acquisition cycle, as will be described in greater detail below. As will be understood, threads (<NUM>) are configured to engage threads (<NUM>) of threaded portion (<NUM>) of carriage nut (<NUM>). Thus, it should be understood that rotation of carriage nut (<NUM>) via lead screw (<NUM>) relative to cocking member (<NUM>) will generally result in axial translation of cocking member (<NUM>) relative to carriage nut (<NUM>) and lead screw (<NUM>).

As described above, threads (<NUM>) of bore (<NUM>) are generally limited to the length of stop portion (<NUM>). Because a portion of bore (<NUM>) in the present example is un-threaded (e.g., the portion corresponding to slide portion (<NUM>)), it should be understood that bore (<NUM>) can receive at least a portion of slide portion (<NUM>) of carriage nut (<NUM>). However, because slide portion (<NUM>) defines a diameter approximately equivalent to the major diameter of threaded portion (<NUM>) of carriage nut (<NUM>), it should be understood that as cocking member (<NUM>) moves proximally relative to carriage nut (<NUM>) and lead screw (<NUM>) such relative motion will only be permitted until threads (<NUM>) reach slide portion (<NUM>) of carriage nut (<NUM>). Once threads (<NUM>) reach slide portion (<NUM>) of carriage nut (<NUM>), an interference between the major diameter of threads (<NUM>) and the outer diameter of slide portion (<NUM>) will prevent further proximal movement of cocking member (<NUM>). Moreover, threads (<NUM>) at this stage will be adjacent to intended portion (<NUM>) and therefore disengaged with threads (<NUM>) of threaded portion (<NUM>).

Lower portion (<NUM>) of actuation tab (<NUM>) extends downwardly from upper portion (<NUM>). Lower portion (<NUM>) is generally configured to be received within receiving feature (<NUM>) of piercer (<NUM>). As will be described in greater detail below, when lower portion (<NUM>) is received within receiving feature (<NUM>) of piercer (<NUM>), actuation member (<NUM>) is generally permitted to drive piercer (<NUM>) through a predetermined sequence of movements via lower portion (<NUM>). Although not show, it should be understood that in examples where upper portion (<NUM>) is received within a channel or track of outer housing (<NUM>) or an intermediate internal housing, such a channel or track may include an opening or additional channel to prevent lower portion (<NUM>) to extend through such a channel or track to receiving feature (<NUM>) of piercer (<NUM>).

Piercer retraction assembly (<NUM>) is disposed proximally of cocking member (<NUM>) and actuation member (<NUM>). As will be described in greater detail below, piercer retraction assembly (<NUM>) is generally configured to axially translate piercer drive assembly (<NUM>) relative to lead screw (<NUM>). Piercer retraction assembly (<NUM>) comprises a first retraction member (<NUM>) and a second retraction member (<NUM>), and a retainer (<NUM>) disposed between first retraction member (<NUM>) and second retraction member (<NUM>).

First retraction member (<NUM>) comprises a body (<NUM>) and a support arm (<NUM>). Body (<NUM>) defines a bore (<NUM>) extending entirely through body (<NUM>). Body (<NUM>) further includes a counter-bore (<NUM>) disposed adjacent to bore (<NUM>). Counter-bore (<NUM>) extends distally only partially though body (<NUM>) from the proximal end thereof. As will be described in greater detail below, bore (<NUM>) and counter-bore (<NUM>) are generally sized to receive slide portion (<NUM>) of cocking member (<NUM>) and slide portion (<NUM>) of carriage nut (<NUM>). Bore (<NUM>) defines a diameter that is generally undersized relative to a diameter defined by retainer (<NUM>), while counter-bore (<NUM>) defines a diameter that is generally oversized relative to the diameter defined by retainer (<NUM>). As will be described in greater detail below, this difference in diameter between bore (<NUM>) and counter-bore (<NUM>) is configured to secure retainer (<NUM>) between first retraction member (<NUM>) and second retraction member (<NUM>).

Support arm (<NUM>) of first retraction member (<NUM>) extends distally from body (<NUM>). The distal extension of support arm (<NUM>) defines a length that is generally equivalent to spring (<NUM>) in a compressed state. On the distal end of support arm (<NUM>), support arm (<NUM>) defines a receiving indentation (<NUM>). Receiving indentation (<NUM>) is generally configured to receive at least a portion of release member (<NUM>) of actuation member (<NUM>). As will be described in greater detail below, receiving indentation (<NUM>) is generally configured to operate in conjunction with at least a portion of release assembly (<NUM>) to selectively hold release member (<NUM>) in a predetermined position relative to first retraction member (<NUM>).

Second retraction member (<NUM>) comprises a body (<NUM>) having a generally rectangular shape. Body (<NUM>) defines a bore (<NUM>) and a counter-bore (<NUM>) disposed coaxially with bore (<NUM>). Bore (<NUM>) extends entirely though body (<NUM>), while counter-bore (<NUM>) extends distally through only a portion of body (<NUM>) from the distal end thereof. Bore (<NUM>) and counter-bore (<NUM>) are both configured to receive at least a portion of lead screw (<NUM>) such that lead screw (<NUM>) can extend entirely though second retraction member (<NUM>). However, a diameter defined by counter-bore (<NUM>) is larger than a diameter defined by bore (<NUM>) to accommodate retainer (<NUM>) within counter-bore (<NUM>). It should be understood that this differential in the diameters of bore (<NUM>) and counter-bore (<NUM>) is configured to prevent proximal movement of retainer (<NUM>) relative to second retraction member (<NUM>) such that retainer (<NUM>) is generally held between first retraction member (<NUM>) and second retraction member (<NUM>).

Bore (<NUM>) further includes a protrusion (<NUM>) extending downwardly into the space defined by bore (<NUM>). Protrusion (<NUM>) comprises a generally cylindrical shape, although any other suitable shape may be used. As will be described in greater detail below, protrusion (<NUM>) is configured to engage threads (<NUM>) of lead screw (<NUM>) to drive translation of second retraction member (<NUM>) in response to rotation of lead screw (<NUM>).

As described above, retainer (<NUM>) is disposed between first retraction member (<NUM>) and second retraction member (<NUM>). Retainer (<NUM>) generally comprises a circular shape similar to a washer or other similar structure. Retainer (<NUM>) includes a bore (<NUM>) extending entirely though retainer (<NUM>). Bore (<NUM>) of retainer (<NUM>) is sized to permit retainer (<NUM>) to fit within annular channel (<NUM>) of carriage nut (<NUM>). Because retainer (<NUM>) is secured between first retraction member (<NUM>) and second retraction member (<NUM>), it should be understood that when retainer (<NUM>) generally axially secures movement of carriage nut (<NUM>) relative to piercer retraction assembly (<NUM>) via engagement between retainer (<NUM>) and annular channel (<NUM>). Thus, it should be understood that axial movement of carriage nut (<NUM>) will generally result in axial movement of piercer retraction assembly (<NUM>). As will be described in greater detail below, this relationship between movement of carriage nut (<NUM>) and piercer retraction assembly (<NUM>) generally results in retraction of piercer (<NUM>) during the tissue acquisition cycle.

While retainer (<NUM>) axially secures movement of carriage nut (<NUM>) relative to piercer retraction assembly (<NUM>), it should be understood that carriage nut (<NUM>) is rotatably movable relative to piercer retraction assembly (<NUM>). In other words, retainer (<NUM>) only secures axial movement of carriage nut (<NUM>), not rotational movement. Although not shown, it should be understood that in some examples retainer (<NUM>) can be adjacent to one or more bearings to disposed within either or both counter-bores (<NUM>, <NUM>) of first retraction member (<NUM>) and second retraction member (<NUM>), respectively. In such examples, bearings can be used to promote the rotatability of carriage nut (<NUM>) relative to piercer retraction assembly (<NUM>). Additionally, although retainer (<NUM>) is shown as having a generally circular shape, it should be understood that in some examples retainer (<NUM>) may comprise a variety of other shapes. For instance, in other examples retainer (<NUM>) comprises a c-washer, a snap-on washer, a circlip, a Jesus clip, and/or any other suitable retaining feature as will be apparent to those of ordinary skill in the art in view of the teachings herein.

When piercer drive assembly (<NUM>) is assembled (e.g., as seen in <FIG>), spring (<NUM>) is disposed between the proximal end of actuation member (<NUM>) and the distal end of body (<NUM>) of first retraction member (<NUM>). In addition, spring (<NUM>) is disposed coaxially around slide portion (<NUM>) of cocking member (<NUM>) and/or coaxially around slide portion (<NUM>) of carriage nut (<NUM>), depending on the particular stage of operation of drive assembly (<NUM>). As will be described in greater detail below, spring (<NUM>) is generally configured to drive actuation member (<NUM>) distally after actuation member (<NUM>) is released by release assembly (<NUM>). Spring (<NUM>) generally defines an outer diameter that approximately corresponds to the outer diameter of slide portion (<NUM>) of cocking member (<NUM>). Although spring (<NUM>) of the present example is shown as a coil spring, it should be understood that any other suitable resilient member may be used as will be apparent to those of ordinary skill in the art in view of the teachings herein.

<FIG> and <FIG> show release assembly (<NUM>) in greater detail. As can be seen, release assembly (<NUM>) comprises a nut member (<NUM>), a secondary lead screw (<NUM>), a motor assembly (<NUM>), a first latch member (<NUM>), and a second latch member (<NUM>). Nut member (<NUM>) comprises a body (<NUM>) with an elongate bore (<NUM>) extending longitudinally therethrough. Although not shown, it should be understood that within body (<NUM>), bore (<NUM>) includes a threaded portion (not shown) including threads (not shown) extending into bore (<NUM>). As will be described in greater detail below, threaded portion of bore (<NUM>) is configured to engage at least a portion of secondary lead screw (<NUM>) to permit secondary lead screw (<NUM>) to drive proximal and distal translation of nut member (<NUM>).

Nut member (<NUM>) further includes a first latch actuator (<NUM>) and a second latch actuator (<NUM>) extending downwardly from body (<NUM>). Both first latch actuator (<NUM>) and second latch actuator (<NUM>) comprise a generally cylindrical shape, although any other suitable shape may be used. First latch actuator (<NUM>) is associated with first latch member (<NUM>), while second latch actuator (<NUM>) is associated with second latch member (<NUM>). As will be described in greater detail below, latch actuators (<NUM>, <NUM>) are generally configured to engage with a corresponding latch member (<NUM>, <NUM>) to release cutter drive assembly (<NUM>) and piercer drive assembly (<NUM>) to fire cutter (<NUM>) and piercer (<NUM>), respectively.

Secondary lead screw (<NUM>) comprises a drive rod (<NUM>) and a drive member (<NUM>). Drive rod (<NUM>) defines a generally cylindrical shape with a plurality of threads (<NUM>) extending along at least a portion of the length of drive rod (<NUM>). Threads (<NUM>) are configured to engage corresponding threads disposed within nut member (<NUM>). This engagement between threads (<NUM>) of drive rod (<NUM>) and the threads of nut member (<NUM>) generally results in the conversion of rotation motion of secondary lead screw (<NUM>) into translation of nut member (<NUM>). As will be described in greater detail below, this motion of nut member (<NUM>) via lead screw (<NUM>) is generally configured to selectively initiate firing of cutter (<NUM>) and piercer (<NUM>).

Drive member (<NUM>) of secondary lead screw (<NUM>) is fixedly secured to the proximal end of drive rod (<NUM>). Drive member (<NUM>) is configured to impart rotary motion onto drive rod (<NUM>) from motor assembly (<NUM>). In particular, drive member (<NUM>) comprises a plurality of teeth (<NUM>). As will be described in greater detail below, teeth (<NUM>) are configured to engage at least a portion of motor assembly (<NUM>) such that rotatory motion provided by motor assembly (<NUM>) is communicated to drive rod (<NUM>) via teeth (<NUM>) of drive member (<NUM>).

Motor assembly (<NUM>) assembly comprises a rotary power source (<NUM>) and a drive member (<NUM>) in rotary communication with rotary power source (<NUM>). Rotary power source (<NUM>) in the present example is configured as an electrical motor. In other examples, rotary power source (<NUM>) can be configured as a variety of other rotary power sources such as pneumatic motors, piezoelectric motors, and/or etc..

Drive member (<NUM>) of motor assembly (<NUM>) is configured to communicate rotary power from rotary power source (<NUM>) to secondary lead screw (<NUM>). In particular, drive member (<NUM>) comprises a plurality of teeth (<NUM>) that are configured to engage with teeth (<NUM>) of drive member (<NUM>) described above with respect to secondary lead screw (<NUM>). Though engagement between teeth (<NUM>, <NUM>), drive members (<NUM>, <NUM>) are rotated, thereby communicating rotary power from motor (<NUM>) to drive member (<NUM>) of secondary lead screw (<NUM>). Although drive members (<NUM>, <NUM>) are described herein as being essentially gears with teeth (<NUM>, <NUM>), it should be understood that in other examples any other suitable rotary transmission may be used. By way of example only, suitable rotary transmissions may include a belt drive, a drive with additional gears to provide a gear ratio between motor (<NUM>) and drive rod (<NUM>), and/or etc..

First latch member (<NUM>) comprises lever portion (<NUM>), a pivot portion (<NUM>), and a catch portion (<NUM>). Lever portion (<NUM>), pivot portion (<NUM>), and catch portion (<NUM>) are all integrally connected to form L-shaped structure. Lever portion (<NUM>) and catch portion (<NUM>) each define one leg of the L-shape, pivot portion (<NUM>) is disposed between lever portion (<NUM>) and catch portion (<NUM>). Pivot portion (<NUM>) includes an opening (<NUM>) extending entirely through latch member (<NUM>) such that a pin or other similar structure may be received by opening (<NUM>) for pivoting of first latch member (<NUM>) about an axis defined by opening (<NUM>). As will be described in greater detail below, this pivoting action generally permits first latch member (<NUM>) to selectively catch and release release member (<NUM>) of cutter drive assembly (<NUM>).

Catch portion (<NUM>) defines a ramp feature (<NUM>) and a recessed feature (<NUM>). Ramp feature (<NUM>) is generally triangular in shape, while adjacent recessed feature (<NUM>) is generally semicircular. Both ramp feature (<NUM>) and recessed feature (<NUM>) are configured to engage release member (<NUM>) of cutter drive assembly (<NUM>). For instance, and as will be described in greater detail below, ramp feature (<NUM>) functions to pivot first latch member (<NUM>) away from release member (<NUM>) to a receiving or releasing position so that release member (<NUM>) can enter recessed feature (<NUM>). Similarly, recessed feature (<NUM>) catches or otherwise selectively secures release member (<NUM>) when first latch member (<NUM>) is pivoted to a cocked position. Although not shown herein, it should be understood that in some examples, first latch member (<NUM>) may include a resilient feature to resiliently bias first latch member (<NUM>) toward the cocked position once release member (<NUM>) is received by recessed feature (<NUM>).

Second latch member (<NUM>) comprises lever portion (<NUM>), a pivot portion (<NUM>), and a catch portion (<NUM>). Lever portion (<NUM>), pivot portion (<NUM>), and catch portion (<NUM>) are all integrally connected to form an L-shaped structure. Lever portion (<NUM>) and catch portion (<NUM>) each define one leg of the L-shape, pivot portion (<NUM>) is disposed between lever portion (<NUM>) and catch portion (<NUM>). Pivot portion (<NUM>) includes an opening (<NUM>) extending entirely through latch member (<NUM>) such that a pin or other similar structure may be received by opening (<NUM>) for pivoting of second latch member (<NUM>) about an axis defined by opening (<NUM>). As will be described in greater detail below, this pivoting action generally permits second latch member (<NUM>) to selectively catch and release release member (<NUM>) of piercer drive assembly (<NUM>).

Catch portion (<NUM>) defines a ramp feature (<NUM>) and a recessed feature (<NUM>). Ramp feature (<NUM>) is generally triangular in shape, while adjacent recessed feature (<NUM>) is generally semicircular. Both ramp feature (<NUM>) and recessed feature (<NUM>) are configured to engage release member (<NUM>) of piercer drive assembly (<NUM>). For instance, and as will be described in greater detail below, ramp feature (<NUM>) functions to pivot second latch member (<NUM>) away from release member (<NUM>) to a receiving or releasing position so that release member (<NUM>) can enter recessed feature (<NUM>). Similarly, recessed feature (<NUM>) catches or otherwise selectively secures release member (<NUM>) when second latch member (<NUM>) is pivoted to a cocked position. Although not shown herein, it should be understood that in some examples, first latch member (<NUM>) may include a resilient feature to resiliently bias first latch member (<NUM>) toward the cocked position once release member (<NUM>) is received by recessed feature (<NUM>).

<FIG> show an exemplary use of biopsy device (<NUM>) described above. In particular, in such a use, drive assembly (<NUM>) is generally used to cock and then fire piercer (<NUM>) and cutter (<NUM>) in a predetermined sequence to penetrate a suspicious lesion and then sever a tissue sample thereof. Once piercer (<NUM>) and cutter (<NUM>) are fired, piercer (<NUM>) is retracted relative to cutter (<NUM>) to permit collection of the severed tissue by an operator. The cocking and firing process may then be repeated as many times as desired to collect as many tissue samples as desired by the user.

<FIG> show an exemplary cocking sequence that results in piercer (<NUM>) and cutter (<NUM>) being prepared for firing. In the cocking sequence, drive assembly (<NUM>) can begin in an initial position as shown in <FIG>. Alternatively, and as will be described in greater detail below, drive assembly (<NUM>) may begin in a cocked position as shown in <FIG>. In the initial position, piercer (<NUM>) and cutter (<NUM>) are each in a distal position. Correspondingly, cutter drive assembly (<NUM>) and piercer drive assembly (<NUM>) are also in a distal uncocked position. Release assembly (<NUM>) is disengaged from both cutter drive assembly (<NUM>) and piercer drive assembly (<NUM>) when cutter drive assembly (<NUM>) and piercer drive assembly (<NUM>) are in the distal position.

When cutter drive assembly (<NUM>) is in the distal position, cocking member (<NUM>) is positioned on the distal end of first threaded portion (<NUM>) of lead screw (<NUM>). Actuation member (<NUM>) is positioned adjacent to stop portion (<NUM>) of cocking member (<NUM>) via spring (<NUM>). In particular, because release member (<NUM>) of actuation member (<NUM>) is disengaged from release assembly (<NUM>), release member (<NUM>) is freely movable along the axis of lead screw (<NUM>). Despite actuation member (<NUM>) being freely movable along the axis of lead screw (<NUM>), spring (<NUM>) is resiliently biased to urge actuation member (<NUM>) distally into the position shown in <FIG>. Thus, actuation member (<NUM>) is urged adjacent to cocking member (<NUM>) by spring (<NUM>).

When piercer drive assembly (<NUM>) is in the distal position, cocking member (<NUM>) is positioned on the distal end of threaded portion (<NUM>) of carriage nut (<NUM>). Carriage nut (<NUM>) is correspondingly positioned on the distal end of second threaded portion (<NUM>) of lead screw (<NUM>) such that cocking member (<NUM>) is in the distal most position relative to both carriage nut (<NUM>) and lead screw (<NUM>). Actuation member (<NUM>) is positioned adjacent to stop portion (<NUM>) of cocking member (<NUM>) via spring (<NUM>). In particular, because release member (<NUM>) of actuation member (<NUM>) is disengaged from release assembly (<NUM>), release member (<NUM>) is freely movable along the axis of lead screw (<NUM>) and carriage nut (<NUM>). Despite actuation member (<NUM>) being freely movable along the axis of lead screw (<NUM>) and carriage nut (<NUM>), spring (<NUM>) is resiliently biased to urge actuation member (<NUM>) distally into the position shown in <FIG>. Thus, actuation member (<NUM>) is urged adjacent to cocking member (<NUM>) by spring (<NUM>).

In the initial position, piercer retraction assembly (<NUM>) of piercer drive assembly (<NUM>) is also in a distal position. However, when piercer retraction assembly (<NUM>) is in the distal position, piercer retraction assembly (<NUM>) is generally separate from cocking member (<NUM>) and actuation member (<NUM>). As described above, piercer retraction assembly (<NUM>) is axially fixed relative to carriage nut (<NUM>) by engagement between retainer of retraction assembly (<NUM>) and annular channel (<NUM>) of carriage nut (<NUM>). Because of this, piercer retraction assembly (<NUM>) is axially fixed near the distal end of carriage nut (<NUM>) with axial movement of piercer retraction assembly (<NUM>) only resulting from axial movement of carriage nut (<NUM>).

To move drive assembly (<NUM>) into the cocked position, an operator may actuate actuation member (<NUM>) on the exterior of outer housing (<NUM>). Actuation of actuation member (<NUM>) then provides a signal to rotary power source (<NUM>) of needle cocking assembly (<NUM>). Upon receiving such a signal, rotary power source (<NUM>) begins rotating lead screw (<NUM>) via rotary communication features (<NUM>, <NUM>) in a first direction as shown in <FIG>.

Rotation of lead screw (<NUM>) in the first direction generally causes cutter drive assembly (<NUM>) and piercer drive assembly (<NUM>) to translate proximally. In particular, rotation of lead screw (<NUM>) causes threads (<NUM>) of first threaded portion (<NUM>) to engage threads (<NUM>) of cocking member (<NUM>). This engagement between threads (<NUM>, <NUM>) causes cocking member (<NUM>) to translate proximally. As cocking member (<NUM>) is translated proximally, stop portion (<NUM>) of cocking member (<NUM>) engages actuation member (<NUM>) to correspondingly push actuation member (<NUM>) proximally. Actuation member (<NUM>) in turn acts on spring (<NUM>) to thereby compress spring (<NUM>).

Proximal translation of cocking member (<NUM>) and actuation member (<NUM>) continues until release member (<NUM>) contacts first latch member (<NUM>) of release assembly (<NUM>). Once such contact is made, release member (<NUM>) of actuation member (<NUM>) engages ramp feature (<NUM>) of first latch member (<NUM>) to pivot first latch member (<NUM>) outwardly (e.g., into the page of <FIG>) as actuation member (<NUM>) is driven proximally. Proximal translation of actuation member (<NUM>) and pivoting of first latch member (<NUM>) will continue until release member (<NUM>) is adjacent to recessed feature (<NUM>) of first latch member (<NUM>).

Once release member (<NUM>) of actuation member (<NUM>) is adjacent to recessed feature (<NUM>) of first latch member (<NUM>), rotation of lead screw (<NUM>) and corresponding proximal translation of actuation member (<NUM>) via cocking member (<NUM>) will stop. At this stage, first latch member (<NUM>) will have pivoted inwardly (e.g., out of the page of <FIG>) to capture release member (<NUM>) of actuation member (<NUM>) within recessed feature (<NUM>) of first latch member (<NUM>). Once release member (<NUM>) is captured within recessed feature (<NUM>), actuation member (<NUM>) will be generally held in the axial position shown in <FIG> via first latch member (<NUM>).

Rotation of lead screw (<NUM>) also rotates carriage nut (<NUM>) via key (<NUM>) of carriage nut (<NUM>) and keyway (<NUM>) of lead screw (<NUM>). Upon rotation of carriage nut (<NUM>) piercer drive assembly (<NUM>) is generally translated proximally. In particular, upon rotation of carriage nut (<NUM>), threads (<NUM>) of carriage nut (<NUM>) engage threads (<NUM>) disposed within bore (<NUM>) of cocking member (<NUM>). The engagement between threads (<NUM>, <NUM>) causes cocking member (<NUM>) to translate proximally. As cocking member (<NUM>) is translated proximally, stop portion (<NUM>) of cocking member (<NUM>) engages actuation member (<NUM>) to correspondingly push actuation member (<NUM>) proximally. Actuation member (<NUM>) in turn acts on spring (<NUM>) to thereby compress spring (<NUM>).

Proximal translation of cocking member (<NUM>) and actuation member (<NUM>) continues until release member (<NUM>) contacts second latch member (<NUM>) of release assembly (<NUM>). Once such contact is made, release member (<NUM>) of actuation member (<NUM>) engages ramp feature (<NUM>) of second latch member (<NUM>) to pivot second latch member (<NUM>) outwardly (e.g., into the page of <FIG>) as actuation member (<NUM>) is driven proximally. Proximal translation of actuation member (<NUM>) and pivoting of second latch member (<NUM>) will continue until release member (<NUM>) is adjacent to recessed feature (<NUM>) of second latch member (<NUM>).

Once release member (<NUM>) of actuation member (<NUM>) is adjacent to recessed feature (<NUM>) of second latch member (<NUM>), rotation of carriage nut (<NUM>) via lead screw (<NUM>) and corresponding proximal translation of actuation member (<NUM>) via cocking member (<NUM>) will stop. At this stage, second latch member (<NUM>) will have pivoted inwardly (e.g., out of the page of <FIG>) to capture release member (<NUM>) of actuation member (<NUM>) within recessed feature (<NUM>) of second latch member (<NUM>). Once release member (<NUM>) is captured within recessed feature (<NUM>), actuation member (<NUM>) will be generally held in the axial position shown in <FIG> via second latch member (<NUM>).

Once both cutter drive assembly (<NUM>) and piercer drive assembly (<NUM>) are translated to the proximal positions shown in <FIG>, drive assembly (<NUM>) is in a cocked position. Although drive assembly (<NUM>) is shown and described herein as initially transitioning to the cocked position from the initial position, it should be understood that in some examples the procedure may begin with drive assembly (<NUM>) being in the cocked position. Regardless, in the cocked position, springs (<NUM>, <NUM>) are compressed for firing. However, because each cocking member (<NUM>, <NUM>) is adjacent to each actuation member (<NUM>, <NUM>), cutter (<NUM>) and piercer (<NUM>) cannot be fired. Thus, it should be understood that when drive assembly (<NUM>) is in the cocked position, cutter (<NUM>) and piercer (<NUM>) are merely in position for firing, but drive assembly (<NUM>) is not yet fully armed.

While drive assembly (<NUM>) is in the cocked position, an operator may inert needle assembly (<NUM>) into tissue of a patient. As shown in <FIG>, insertion may be performed to position needle assembly (<NUM>) adjacent to a suspicious lesion (LE). In some uses, inserting needle assembly (<NUM>) into tissue of a patient may be desirable to prevent inadvertent firing of piercer (<NUM>) or cutter (<NUM>). Of course, it should be understood that an operator may position needle assembly (<NUM>) when drive assembly (<NUM>) is in other positions, as will be described in greater detail below.

To prepare needle assembly (<NUM>) for firing, an operator may transition drive assembly (<NUM>) from the cocked position shown in <FIG> to a ready position shown in <FIG>. To initiate the transition of drive assembly (<NUM>) from the cocked position to the ready position, an operator may push actuation member (<NUM>) a second time. Pressing actuation member (<NUM>) once again sends a signal to rotary power source (<NUM>) of needle cocking assembly (<NUM>) to initiate rotation of lead screw (<NUM>) in a second direction, opposite of the first direction.

Rotation of lead screw (<NUM>) in the opposite direction generally causes cocking member (<NUM>) of cutter drive assembly (<NUM>) and cocking member (<NUM>) of piercer drive assembly (<NUM>) to each translate distally relative to lead screw (<NUM>). In particular, threads (<NUM>) of first threaded portion (<NUM>) again engage threads (<NUM>) of cocking member (<NUM>). However, due to rotation of lead screw (<NUM>) in the second direction, this engagement causes cocking member (<NUM>) to translate distally. Because actuation member (<NUM>) and spring (<NUM>) are not fixedly secured to cocking member (<NUM>), actuation member (<NUM>) and spring (<NUM>) remain held in position by first latch member (<NUM>) of release assembly (<NUM>). Translation of cocking member (<NUM>) continues until cocking member (<NUM>) reaches the distal end of first threaded portion (<NUM>) of lead screw (<NUM>) as shown in <FIG>.

Similarly, with respect to piercer drive assembly (<NUM>), threads (<NUM>) of carriage nut (<NUM>) again engage threads (<NUM>) of cocking member (<NUM>). As described above, rotation of lead screw (<NUM>) results in rotation of carriage nut (<NUM>) via engagement between key (<NUM>) and keyway (<NUM>). Accordingly, rotation of lead screw (<NUM>) causes carriage nut (<NUM>) to rotate in the second direction. Rotation of carriage nut (<NUM>) in the second direction causes cocking member (<NUM>) to translate distally via engagement of threads (<NUM>, <NUM>). Because actuation member (<NUM>) and spring (<NUM>) are not fixedly secured to cocking member (<NUM>), actuation member (<NUM>) and spring (<NUM>) remain held in position by second latch member (<NUM>) of release assembly (<NUM>). Translation of cocking member (<NUM>) continues until cocking member (<NUM>) reaches the distal end of threaded portion (<NUM>) of carriage nut (<NUM>) as shown in <FIG>.

Once cocking member (<NUM>) of cutter drive assembly (<NUM>) and cocking member (<NUM>) of piercer drive assembly (<NUM>) are positioned in the distal position as shown in <FIG>, drive assembly (<NUM>) is in the ready position. Once drive assembly (<NUM>) is in the ready position, an operator may position needle assembly (<NUM>) into tissue of a patient adjacent to suspicious lesion (LE) as shown in <FIG>, if operator had not already done so prior to transitioning drive assembly (<NUM>) from the cocking position to the ready position.

With drive assembly (<NUM>) in the ready position (<FIG>), and needle assembly (<NUM>) placed near a suspicious lesion (SE) (<FIG>), an operator may next initiate a firing sequence. <FIG>, and <FIG> show the firing sequence in greater detail. To initiate the firing sequence, an operator may press actuation member (<NUM>) on outer housing (<NUM>) a third time. When actuation member (<NUM>) is pressed, a signal now sent to motor (<NUM>) of release assembly (<NUM>). This signal causes motor (<NUM>) to supply rotary power to secondary lead screw (<NUM>) via drive members (<NUM>, <NUM>) to thereby rotate secondary lead screw (<NUM>). As secondary lead screw (<NUM>) rotates, threads (<NUM>) of secondary lead screw (<NUM>) engage the threads disposed within body (<NUM>) of nut member (<NUM>).

Engagement between threads (<NUM>) of secondary lead screw (<NUM>) and the threads of nut member (<NUM>) during rotation of secondary lead screw (<NUM>) causes nut member (<NUM>) to retract proximally. As nut member (<NUM>) retracts proximally, second latch actuator (<NUM>) first comes into contact with lever portion (<NUM>) of second latch member (<NUM>). Due to the spacing between first latch actuator (<NUM>) and second latch actuator (<NUM>), it should be understood that only second latch actuator (<NUM>) contacts second latch member (<NUM>) initially. As will be described in greater detail below, further proximal actuation of nut member (<NUM>) is needed for first latch actuator (<NUM>) to engage lever portion (<NUM>) of first latch member (<NUM>).

As nut member (<NUM>) continues to translate proximally, second latch actuator (<NUM>) engages lever portion (<NUM>) of second latch member (<NUM>) to begin to pivot second latch member (<NUM>) away from release member (<NUM>) of piercer drive assembly (<NUM>). Further proximal translation of nut member (<NUM>) eventually results in second latch member (<NUM>) fully pivoting to disengage release member (<NUM>) from recessed feature (<NUM>) of second latch member (<NUM>) as shown in <FIG>.

Once release member (<NUM>) is disengaged from recessed feature (<NUM>) of second latch member (<NUM>), actuation member (<NUM>) is free to translate axially relative to lead screw (<NUM>). Because spring (<NUM>) was previously compressed during cocking, spring (<NUM>) will now rapidly urge actuation member (<NUM>) distally. As described above, actuation member (<NUM>) includes actuation tab (<NUM>), which is secured to receiving feature (<NUM>) of piercer (<NUM>). Thus, it should be understood that rapid translation of actuation member (<NUM>) will result in corresponding rapid translation of piercer (<NUM>). Rapid translation of piercer (<NUM>) will result in distal tip (<NUM>) and notch (<NUM>) of piercer (<NUM>) penetrating through suspicious lesion (LE) as shown in <FIG>.

Once firing of piercer (<NUM>) has occurred, motor (<NUM>) of release assembly (<NUM>) will stop, thereby stopping further proximal movement of nut member (<NUM>) via secondary lead screw (<NUM>). In the present use, proximal translation of nut member (<NUM>) will stop prior to first latch actuator (<NUM>) reaching first latch member (<NUM>) for firing of cutter (<NUM>). In other words, after piercer (<NUM>) is fired, the firing sequence is paused prior to firing cutter (<NUM>). Alternatively, in some uses, motor (<NUM>) may continue rotating without stopping after firing of piercer (<NUM>). In these uses, piercer (<NUM>) is fired first, followed by a relatively short delay, and then cutter (<NUM>) is fired using the sequence described below.

To fire cutter (<NUM>) under the present use, an operator may reinitiate rotation of motor (<NUM>) and corresponding proximal translation of nut member (<NUM>) by pressing actuation member (<NUM>) on outer housing (<NUM>) a fourth time. This causes motor (<NUM>) of release assembly (<NUM>) to continue rotation of secondary lead screw (<NUM>). As similarly described above, engagement between threads (<NUM>) of secondary lead screw (<NUM>) and the threads of nut member (<NUM>) during rotation of secondary lead screw (<NUM>) causes nut member (<NUM>) to retract proximally. As nut member (<NUM>) continues to retract proximally first latch actuator (<NUM>) will engage lever portion (<NUM>) of first latch member (<NUM>). Further proximal translation of nut member (<NUM>) will result in first latch actuator (<NUM>) pushing lever portion (<NUM>) to pivot first latch member (<NUM>) away from release member (<NUM>) of actuation member (<NUM>) as shown in <FIG>. This pivoting of first latch member (<NUM>) will eventually result in disengagement of release member (<NUM>) of actuation member (<NUM>) from first latch member (<NUM>).

With release member (<NUM>) of actuation member (<NUM>) disengaged from first latch member (<NUM>), actuation member (<NUM>) is free to translate axially relative to lead screw (<NUM>). Because spring (<NUM>) was previously compressed during cocking, spring (<NUM>) will now rapidly urge actuation member (<NUM>) distally. As described above, actuation member (<NUM>) includes actuation tab (<NUM>), which is secured to receiving feature (<NUM>) of cutter (<NUM>). Thus, it should be understood that rapid translation of actuation member (<NUM>) will result in corresponding rapid translation of cutter (<NUM>). Rapid translation of cutter (<NUM>) will result in distal end (<NUM>) of cutter (<NUM>) penetrating through suspicious lesion (LE) as shown in <FIG> to sever a tissue sample into notch (<NUM>) of piercer (<NUM>).

<FIG> show an exemplary sequence for retracting piercer (<NUM>) relative to cutter (<NUM>) to collect a tissue sample after the tissue sample has been acquired using the firing sequence described above. As will be described in greater detail below, the piercer (<NUM>) retraction sequence generally involves retracting piercer (<NUM>) relative to cutter (<NUM>) to expose notch (<NUM>) of piercer within the tissue collection feature (<NUM>) of cutter (<NUM>). When piercer (<NUM>) is retracted in this way, an operator may extract a tissue sample from notch (<NUM>) for further analysis and processing.

The piercer (<NUM>) retraction sequence begins by returning drive assembly (<NUM>) to the cocked position described above with respect to <FIG>. When drive assembly (<NUM>) is in the cocked position shown in <FIG> and <FIG>, piercer (<NUM>) is correspondingly disposed in a distal position. As can be seen in <FIG>, when piercer is in the distal position, tissue collection feature (<NUM>) of cutter (<NUM>) is generally blocked by piercer (<NUM>). To return drive assembly (<NUM>) to the cocked position, an operator may press actuation member (<NUM>) on outer housing (<NUM>) a fifth time. As described above, drive assembly (<NUM>) is generally transitioned to the cocked position by rotating lead screw (<NUM>) in the first direction to translate cocking members (<NUM>, <NUM>) of cutter drive assembly (<NUM>) and piercer drive assembly (<NUM>) proximally relative to lead screw (<NUM>).

Once drive assembly (<NUM>) is returned to the cocked position as shown in <FIG> and <FIG>, lead screw (<NUM>) continues to rotate in the first direction. As rotation continues, cocking members (<NUM>, <NUM>) of cutter drive assembly (<NUM>) and piercer drive assembly (<NUM>) will begin to free-wheel relative to lead screw (<NUM>). In particular, cocking member (<NUM>) of cutter drive assembly (<NUM>) will disengage from first threaded portion (<NUM>) of lead screw (<NUM>) as cocking member (<NUM>) transitions to being adjacent to indented portion (<NUM>) of lead screw (<NUM>). Similarly, cocking member (<NUM>) of cutter drive assembly (<NUM>) will disengage from threaded portion (<NUM>) of carriage nut (<NUM>) as cocking member (<NUM>) transitions to being adjacent to indented portion (<NUM>) of carriage nut (<NUM>).

As cocking members (<NUM>, <NUM>) begin to free-wheel as described above, piercer retraction assembly (<NUM>) will begin to engage second threaded portion (<NUM>) of lead screw (<NUM>). In particular, protrusion (<NUM>) of second retraction member (<NUM>) is received by threads (<NUM>) of second threaded portion (<NUM>). As lead screw (<NUM>) rotates, engagement between protrusion (<NUM>) and threads (<NUM>) pulls second retraction member (<NUM>) proximally as shown in <FIG>. Because second retraction member (<NUM>) is secured to first retraction member (<NUM>), proximal movement of second retraction member (<NUM>) also pulls first retraction member (<NUM>) proximally. Additionally, because retainer (<NUM>) is positioned between first retraction member (<NUM>) and second retraction member (<NUM>) to axially secure carriage nut (<NUM>) to piercer retraction assembly (<NUM>), proximal movement of first retraction member (<NUM>) and second retraction member (<NUM>) will result in corresponding proximal movement of carriage nut (<NUM>). With piercer drive assembly (<NUM>) disposed on carriage nut (<NUM>), translation of carriage nut (<NUM>) also results in translation of piercer drive assembly (<NUM>). Thus, it should be understood that as piercer retraction assembly (<NUM>) is driven proximally by rotation of lead screw (<NUM>), corresponding translation of piercer drive assembly (<NUM>) along with piercer (<NUM>) will result.

Proximal translation of piercer retraction assembly (<NUM>), piercer drive assembly (<NUM>), and piercer (<NUM>) continues until piercer retraction assembly (<NUM>) reaches the distal position shown in <FIG>. Once piercer retraction assembly (<NUM>) reaches the distal position, rotation of lead screw (<NUM>) stops, thereby stopping further proximal translation of piercer retraction assembly (<NUM>).

When piercer drive assembly (<NUM>) is in the distal position, piercer (<NUM>) is also in a distal position as shown in <FIG>. As can be seen in <FIG>, when piercer (<NUM>) is in the distal position, notch (<NUM>) of piercer (<NUM>) is aligned with tissue collection feature (<NUM>) of cutter (<NUM>). This alignment provides access to notch (<NUM>) through cut out (<NUM>) in cutter (<NUM>). At this stage, an operator may collect a tissue sample from notch (<NUM>) for further examination, analysis, investigation, and/or etc..

Claim 1:
A core needle biopsy device (<NUM>), comprising:
(a) a needle assembly (<NUM>), wherein the needle assembly (<NUM>) includes a piercer (<NUM>) and a hollow cutter (<NUM>), wherein the piercer (<NUM>) includes a sharp distal tip and a notch (<NUM>) proximal to the distal tip, wherein the piercer (<NUM>) is slidably disposed within the cutter (<NUM>) to sever a tissue sample into the notch of the piercer;
(b) a cutter drive assembly (<NUM>), wherein the cutter drive assembly is configured to selectively fire the cutter (<NUM>);
(c) a piercer drive assembly (<NUM>), wherein the piercer drive assembly is configured to selectively fire the piercer (<NUM>); and
(d) a drive assembly (<NUM>) having a piercer retraction assembly (<NUM>), characterized by the drive assembly including a lead screw (<NUM>) engaged with the piercer drive assembly (<NUM>) and the cutter drive assembly (<NUM>) such that rotation of the lead screw (<NUM>) sequentially translates a portion of the piercer drive assembly (<NUM>) and the cutter drive assembly (<NUM>), wherein rotation of the lead screw (<NUM>) retracts the piercer (<NUM>), via retraction of the piercer retraction assembly (<NUM>), independently of the cutter (<NUM>) while the needle assembly (<NUM>) is disposed within a patient to expose a distal portion of the piercer (<NUM>) to an exterior of a patient while at least a portion of the piercer remains within the cutter (<NUM>).