Patent Description:
Before a biopsy or surgical procedure to remove a lesion within a breast, such as a lumpectomy procedure, the location of the lesion must be identified. For example, mammography or ultrasound imaging may be used to identify and/or confirm the location of the lesion before a procedure. The resulting images may be used by a surgeon during a procedure to identify the location of the lesion and guide the surgeon, e.g., during dissection to access and/or remove the lesion. However, such images are generally two dimensional and therefore provide only limited guidance for localization of the lesion since the breast and any lesion to be removed are three-dimensional structures. Further, such images may provide only limited guidance in determining a proper margin around the lesion, i.e., defining a desired specimen volume to be removed.

To facilitate localization, immediately before a procedure, a wire may be inserted into the breast, e.g., via a needle, such that a tip of the wire is positioned at the location of the lesion. Once the wire is positioned, it may be secured in place, e.g., using a bandage or tape applied to the patient's skin where the wire emerges from the breast. With the wire placed and secured in position, the patient may proceed to surgery, e.g., to have a biopsy or lumpectomy performed.

One problem with using a wire for localization is that the wire may move between the time of placement and the surgical procedure. For example, if the wire is not secured sufficiently, the wire may move relative to the tract used to access the lesion and consequently the tip may misrepresent the location of the lesion. If this occurs, when the location is accessed and tissue removed, the lesion may not be fully removed and/or healthy tissue may be unnecessarily removed. In addition, during the procedure, a surgeon merely estimates the location of the wire tip and lesion, e.g., based on mammograms or other images obtained during wire placement, and may proceed with dissection without any further guidance. Again, since such images are two dimensional, they may provide limited guidance to localize the lesion being treated or removed.

Alternatively, it has been suggested to place a radioactive seed to provide localization during a procedure. For example, a needle may be introduced through a breast into a lesion, and then a seed may be deployed from the needle. The needle may be withdrawn, and the position of the seed may be confirmed using mammography. During a subsequent surgical procedure, a hand-held gamma probe may be placed over the breast to identify a location overlying the seed. An incision may be made and the probe may be used to guide excision of the seed and lesion.

Because the seed is delivered through a needle that is immediately removed, there is risk that the seed may migrate within the patient's body between the time of placement and the surgical procedure. Thus, similar to using a localization wire, the seed may not accurately identify the location of the lesion, particularly, since there is no external way to stabilize the seed once placed. Further, such gamma probes may not provide desired precision in identifying the location of the seed, e.g., in three dimensions, and therefore may only provide limited guidance in localizing a lesion.

Accordingly, apparatus and methods for localization of lesions or other tissue structures in advance of and/or during surgical, diagnostic, or other medical procedures would be useful.

The present disclosure is directed to apparatus and methods for performing surgical or other medical procedures. More particularly, the present disclosure is directed to implantable markers and to apparatus and methods for localizing targets, markers, lesions, and/or other tissue structures within a patient's body during surgical or other medical procedures, e.g., for localizing breast lesions before or during lumpectomy procedures. Embodiments and examples disclosed herein are for illustrative purposes.

In accordance with one embodiment, a system is provided for localization of a target tissue region within a patient's body that includes one or more markers or targets; and a probe for transmitting and receiving electromagnetic signals to detect a target after the target is introduced into a target tissue region and the probe is placed adjacent and/or aimed towards the target tissue region. The probe may include one or more output devices, e.g., a display, speaker, and the like, that provide spatial information based on the spatial relationship of the target relative to the probe, e.g., a distance and/or angular orientation between the probe and the target. Optionally, the system may also include one or more delivery devices for introducing the target(s) into tissue or otherwise into a patient's body, e.g., including a needle, cannula, or other tubular member within which one or more targets may be loaded.

In an exemplary embodiment, the target may include a plurality of angled surfaces that may enhance reflection of the electromagnetic signals from the probe, e.g., such that the target provides a passive marker. For example, the target may be an elongate marker including a plurality of beads coupled to a core element, the beads including angled surfaces and/or edges to enhance detection by the probe. The core element may be biased to one or more predetermined shapes, e.g., a wave shape, a tapered helix, a cylindrical helix, and the like, yet may be sufficiently resilient to be straightened, e.g., to facilitate loading the marker into a delivery device. In another embodiment, the target may include a spherical, elliptical, discus, or other shape, e.g., including one or more surface features to enhance reflection of the electromagnetic signals.

Optionally, the target may include one or more circuits, features, and the like that modulate an incident signal from the probe to facilitate identification of the target, e.g., such that the target provides an active reflector marker. For example, the target may impose a phase shift on signals from the probe that strike the target, e.g., to distinguish the target from other targets, tissue structures, and the like. In another option, the target may include a circuit and power source such that the target may generate predetermined signals in response to detecting a signal from the probe, e.g., to provide an active transponder marker.

Optionally, the target may include a marker releasably or substantially permanently coupled to an elongate flexible tether. Alternatively, the target may include a localization wire including a shaft and a marker on a distal end of the shaft.

In accordance with another embodiment, a system is provided for localization of a target tissue region within a patient's body that includes a delivery device carrying one or more markers or targets sized for implantation within or around the target tissue region; and a probe for transmitting and receiving electromagnetic signals to detect the one or more markers implanted within or around the target tissue region when the probe is placed adjacent the target tissue region and/or aimed at the target tissue region.

In an exemplary embodiment, the delivery device may include a shaft including a proximal end and a distal end sized for introduction through tissue within a patient's body into a target tissue region, and one or more markers deliverable from the distal end. For example, the shaft may include a lumen and a plurality of markers may be carried within the lumen such that the markers may be delivered sequentially from the shaft and implanted in locations within or around a lesion or other target tissue region. Exemplary markers that may be delivered with the delivery device may include a passive marker, an active reflector marker, and an active transponder marker.

In accordance with still another embodiment, a method is provided for localizing a target tissue region within a patient's body that includes introducing a marker or other target through tissue into the target tissue region; placing a probe against the patient's skin or otherwise adjacent the target tissue region and/or aimed towards the target tissue region; and activating the probe, whereupon the probe transmits electromagnetic signals towards the target tissue region, receives electromagnetic signals reflected from the target, and displays, emits, or otherwise provides spatial information to provide a spatial relationship between the target and the probe.

In one embodiment, the target may be a localization wire introduced through the tissue into the target tissue region, the localization wire carrying the target. In another embodiment, the target may be one or more markers implanted within the target tissue region. In yet another embodiment, the target may be a catheter or other device, e.g., that may be introduced into a target region and deployed to delineate a volume or region. The device may include special features that are configured for locating and/or defining the volume, e.g., using an electromagnetic wave probe. Optionally, the target may be placed before or during a diagnostic, therapeutic, and/or surgical procedure, e.g., using stereotactic, ultrasound, or electromagnetic wave based imaging.

In an exemplary embodiment, the target tissue region may include a region within a patient's breast having a lesion therein, and the target may be delivered into or around the lesion. Alternatively, the target tissue region may be located in other regions of the body, e.g.. , within or around the intestines, fallopian tubes, and the like. For example, the target may include a first marker that is introduced into the target tissue region spaced apart from a lesion to define a desired margin for removal of a specimen volume from the target tissue region. Optionally, a second marker and/or a plurality of additional markers may be introduced into the target tissue region spaced apart from the lesion and the first marker to further define the desired margin. Thus, if desired, a three dimensional array of markers may be placed within or around the target tissue region to facilitate localization thereof. A tissue specimen may then be removed from the target tissue region, the tissue specimen including the lesion and the target.

In accordance with yet another embodiment, a method is provided for removing a lesion within a target tissue region of a patient's breast that includes introducing a target through breast tissue into the target tissue region; placing a probe adjacent the patient's skin, e.g., oriented generally towards the target tissue region, the probe transmitting electromagnetic signals towards the target tissue region, receiving electromagnetic signals reflected from the target, and providing spatial information to provide a spatial relationship between the target and the probe; and removing a tissue specimen from the target tissue region, the tissue specimen including the lesion and the target.

In accordance with still another embodiment, a method is provided for removing a lesion within a target tissue region of a patient's breast that includes introducing a target through breast tissue into the target tissue region; placing a probe adjacent the patient's skin, e.g., oriented generally towards the target tissue region, the probe transmitting electromagnetic signals towards the target tissue region and receiving electromagnetic signals reflected from the target; using the probe to determine a desired margin within the target tissue region around the lesion; and removing a tissue specimen from the target tissue region, the tissue specimen defined by the desired margin and including the lesion and the target.

In accordance with the invention, an implantable marker is provided for localization of a target tissue region within a patient's body that includes an elongate core member, and a plurality of beads carried by the core member. The beads include a plurality of surfaces and/or edges to enhance reflection of electromagnetic signals to facilitate identification of the marker. In addition or alternatively, the marker may include an electronic circuit, e.g., embedded in or otherwise carried by one of the beads or the core member, that may provide one of an active reflector and an active transponder.

Other aspects and features will become apparent from consideration of the following description taken in conjunction with the accompanying drawings.

Turning to the drawings, <FIG> shows an exemplary embodiment of a system <NUM> for localization of a target tissue region within a patient's body, such as a tumor, lesion, or other tissue structure within a breast or other location within a body. The system <NUM> generally includes a marker device or localization wire <NUM> and a probe <NUM> for detecting at least a portion of the localization wire <NUM> using electromagnetic pulses, waves, or other signals, such as radar. The localization wire <NUM> may include an elongated member or shaft <NUM> including a proximal end 22a, a distal end 22b, and a target <NUM> on the distal end 22b. Optionally, the system <NUM> may include one or more additional localization wires and/or targets (not shown) in addition to localization wire <NUM>.

The shaft <NUM> may be formed from a relatively rigid material, e.g., a solid rod or hollow tubular body, having sufficient column strength to facilitate percutaneous introduction of the localization wire <NUM> through tissue. The shaft <NUM> may have a length sufficient to extend from a location outside a patient's body through tissue to a target tissue region, e.g., between about half and ten centimeters (<NUM>-<NUM>). Optionally, the shaft <NUM> may be malleable or otherwise plastically deformable, e.g., such that the shaft <NUM> may be bent or otherwise formed into a desired shape, if desired.

The target <NUM> may include one or more features on the distal end 22b of the shaft <NUM> to facilitate localization of the distal end 22b using the probe <NUM>. In the exemplary embodiment shown, the target <NUM> may be a bulbous structure, e.g., a sphere having a larger diameter than the distal end 22b of the shaft <NUM>, e.g., between about half and five millimeters (<NUM>-<NUM>). Optionally, the target <NUM> may include one or more features to enhance electromagnetic signal reception and reflection. For example, the target <NUM> may be formed from one or more materials and/or may have a surface finish that enhances detection by radar, e.g., similar to the markers described elsewhere herein. In alternative embodiments, other shapes and/or geometries may be provided, e.g., cubes, triangles, helixes, and the like, including one or more corners and/or edges that may enhance radar reflection and/or detection, similar to other embodiments herein.

In addition or alternatively, the target <NUM> may have a size and/or shape approximating the size and/or shape of the lesion <NUM>, e.g., to facilitate identifying a desired margin around the lesion <NUM>. For example, the size and/or shape of the lesion <NUM> may be determined in advance, and a target <NUM> may be selected from a set of different size and/or shape targets and secured to the shaft <NUM> (or each target may be provided on its own shaft). In addition or alternatively, if multiple localization wires and/or targets are provided, each target may have a different shape and/or features, e.g., to facilitate distinguishing the targets from one another using the probe <NUM>.

In one embodiment, the shaft <NUM> and target <NUM> may be integrally formed from the same material. Alternatively, the target <NUM> may be formed from different material(s) than the shaft <NUM>, and the target <NUM> may be secured to the distal end 22b, e.g., by bonding with adhesive, welding, soldering, interference fit, threads or other cooperating connectors, and the like. Thus, in this alternative, the target <NUM> may be formed from material that enhances detection by radar relative to the shaft <NUM>.

Optionally, if multiple targets are to be implanted, each target may have a surface, shape, and/or additional material feature that may distinguish a particular target relative to one or more others. For example, each target may absorb or reflect a particular electromagnetic signal that is specific to that target and can be used to uniquely identify it.

In another option, the localization wire <NUM> may include one or more anchoring elements <NUM> on the distal end 22b, e.g., adjacent the target <NUM>, although the target <NUM> itself may stabilize the localization wire <NUM> sufficiently that anchoring elements <NUM> may be unnecessary. As shown, the anchoring elements <NUM> include a plurality of barbs <NUM> (two shown) that extend transversely from the shaft <NUM>, e.g., angled proximally away from the target <NUM>. Thus, the barbs <NUM> may be configured for anchoring the localization wire <NUM> in position after the localization wire <NUM> is inserted into tissue, e.g., allowing the localization wire <NUM> to be advanced distally through tissue while preventing subsequent proximal withdrawal. For example, the barbs <NUM> may be sufficiently flexible such that the barbs <NUM> may be compressed against or otherwise adjacent the shaft <NUM>, e.g., to minimize a profile of the localization wire <NUM> to facilitate advancement, yet resiliently biased to return outwardly to a transverse orientation, as shown.

The probe <NUM> may be a portable device having electromagnetic signal emitting and receiving capabilities, e.g., a micro-power impulse radar (MIR) probe. For example, as shown in <FIG>, the probe <NUM> may be a handheld device including a first end 30a intended to be placed against or adjacent tissue, e.g., a patient's skin or underlying tissue, and a second opposite end 30b, e.g., which may be held by a user. With additional reference to <FIG>, the probe <NUM> generally includes one or more antennas, e.g., a transmit antenna <NUM> and a receive antenna <NUM>, one or more processors or controllers <NUM>, and a display <NUM>.

Turning to <FIG>, the processor <NUM> may include one or more controllers, circuits, signal generators, gates, and the like (not shown) needed to generate signals for transmission by the transmit antenna <NUM> and/or to process signals received from the receive antenna <NUM>. The components of the processor <NUM> may include discrete components, solid state devices, programmable devices, software components, and the like, as desired. For example, as shown, the probe <NUM> may include an impulse generator 36b, e.g., a pulse generator and/or pseudo noise generator (not shown), coupled to the transmit antenna <NUM> to generate transmit signals, and an impulse receiver 36c for receiving signals detected by the receive antenna <NUM>. The processor <NUM> may include a micro controller 36a and a range gate control 36d that alternately activate the impulse generator 36b and impulse receiver 36c to transmit electromagnetic pulses, waves, or other signals via the antenna <NUM>, and then receive any reflected electromagnetic signals via antenna <NUM>. Exemplary signals that may be used include microwave, radio waves, such as micro-impulse radar signals, e.g., in the Ultra Low bandwidth region.

In exemplary embodiments, each of the antennas <NUM>, <NUM> may be a UWB antenna, e.g., a horn obtrusive physical profile, a dipole and patch, or a co-planar antenna, such as a diamond dipole antenna, a single ended elliptical antenna ("SEA"), a patch antenna, and the like. Alternatively, the processor <NUM> may activate a single antenna to operate alternately as a transmit antenna and a receive antenna (not shown) instead of providing separate antennas <NUM>, <NUM>.

For example, each antenna <NUM>, <NUM> may be a TEM horn antenna, such as that disclosed in "<NPL>). Alternatively, each antenna <NUM>, <NUM> may be a patch antenna, such as those disclosed in <CIT>, and in "<NPL>. The patch antenna may be coupled to an enclosure (not shown), e.g., filled with dielectric material, to facilitate use with micro-impulse radar.

In another alternative embodiment, each antenna may be a waveguide horn, e.g., as shown in <FIG>. As shown, antenna <NUM>' includes a casing 32A that is closed on a first end 32B, and open on a second end 32C, and within which a waveguide 32D is mounted. The walls of the casing 32A may be lined with an absorber material 32E, e.g., a broadband silicone absorber material, such as Eccosorb-FGM40, sold by Emerson & Cuming Microwave Products N. of Westerlo, Belgium. The volume within the casing 32A may be filled with a dielectric 32F, e.g., having a relative permittivity of <NUM>. In an exemplary embodiment, the antenna <NUM>' may be a square waveguide horn configured to operate at ultrawide band frequencies <NUM>"UWB") between about three and ten Gigahertz (<NUM>-<NUM>), e.g., having a width of about fifteen by fifteen millimeters (15x15 mm), and a length between the first and second ends 32B-32C of about thirty millimeters (<NUM>). The open end 32B may be oriented outwardly from a probe within which the antenna <NUM>' is mounted, e.g., such that the open end 32B may contact or otherwise be coupled with tissue through which the antenna <NUM>' is intended to transmit and/or receive signals, as described elsewhere herein.

The signals from the impulse receiver 36c may be filtered or otherwise processed, e.g., by a return signal de-clutter and shaper circuit 36e, before being communicated to the micro-controller 36a for further processing, display, storage, transmission, and the like. The circuit 36e may receive signals from the antenna <NUM>, e.g., return echo noise and clutter, may de-clutter the signals, e.g., using LPF, and/or may include digital adaptive filtering and/or pulse shapers, as desired. The micro-controller 36a may then interpret the received and/or processed signals to identify a spatial relationship, e.g., distance, angle, orientation, and the like, of the target <NUM> or other structures relative to the probe <NUM>, as described further below. Exemplary embodiments of processors and/or other components that may be included in the probe <NUM> are disclosed in <CIT> and <CIT>, issued to McEwan.

In an alternative embodiment, the probe <NUM> may be configured to operate as a magneto-radar system, such as that disclosed in <CIT>, issued to McEwan. For example, the probe <NUM> may include a magnetic field excitation source, e.g., an electromagnet (not shown), coupled to a generator and/or current coil driver (not shown), which may be provided within or external to the probe <NUM>. For example, the probe may induce a magnetic field to a marker or other target, generating a pole to pole vibration at a specific frequency that the radar unit may identify and/or recognize to provide a distance measurement or location coordinates. Such a probe may be useful when the target is implanted in tissue, bone, or bodily fluid with a relatively high impedance or dielectric constant that may attenuate the radar pulse from reaching the target or the reflected signal from reaching the radar antenna.

Returning to <FIG>, the probe's display <NUM> may be coupled to the micro-controller 36a for displaying information to a user of the probe <NUM>, e.g., spatial or image data obtained via the antenna(s) <NUM>, <NUM>. For example, the display <NUM> may simply be a readout providing distance, angle, orientation, and/or other data based on predetermined criteria, e.g., based on the relative location of the target <NUM> to the probe <NUM>, as described further below. <FIG> shows an exemplary embodiment of an output for display <NUM> that may be provided, which may include an array of arrows or other indicators 38a and a distance readout 38b. For example, the micro-controller 36a may analyze the received signals to determine in which direction relative to the probe <NUM> a marker (not shown) may be located and activate the appropriate arrow 38a, and display a distance (e.g., "<NUM>" shown) to the marker. Thus, the user may be able to identify in what direction and how far in that direction the marker is located, thereby providing the user guidance towards the marker and the target tissue region within which the marker is implanted.

In addition or alternatively, the display <NUM> may provide other information, e.g., real-time images of the region towards which the probe <NUM> is oriented, i.e., beyond the first end 30a, operational parameters of the probe <NUM>, and the like. Optionally, the probe <NUM> may include one or more other output devices in addition to or instead of the display <NUM>. For example, the probe <NUM> may include one or more speakers (not shown) that may provide audio output, one or more LEDs or other light sources that provide visual output, and the like e.g., to provide information such as spatial information, operation parameters, and the like. For example, a speaker or LED may be activated when the probe <NUM> reaches a predetermined threshold distance from the marker, e.g., a desired margin, or may be activated when successively closer distances are achieved.

Optionally, the probe <NUM> may include other features or components, such as one or more user interfaces, memory, transmitters, receivers, connectors, cables, power sources, and the like (not shown). For example, the probe <NUM> may include one or more batteries or other internal power sources for operating the components of the probe <NUM>. Alternatively, the probe <NUM> may include a cable (not shown) that may be coupled to an external power source, e.g., standard AC power, for operating the components of the probe <NUM>.

Returning to <FIG>, the user controls <NUM> may include one or more input devices, such as a keypad, touch screen, individual buttons, and the like (not shown). The user controls <NUM> may allow the user to perform simple operations, e.g., turn the probe <NUM> on and off, reset the probe <NUM>, and the like, or may allow more complicated control of the probe <NUM>. For example, the user controls <NUM> may allow the sensitivity or other parameters of the probe <NUM> to be adjusted, may allow data to be captured, stored, transmitted remotely, and the like.

Optionally, the probe <NUM> may include internal memory 36f that may record or otherwise store data obtained via the antenna(s) <NUM>, <NUM> and/or micro-controller 36a. For example, the micro-controller 36a may automatically record data during operation, or may be instructed to selectively save data to the memory 36f. In addition or alternatively, the micro-controller 36a may transfer data to one or more external devices, e.g., for storage, display, and the like. For example, the probe <NUM> may include one or more cables (not shown) to allow such data transfer and/or the probe <NUM> may include a transmitter and/or receiver (not shown) for wirelessly transferring data and/or receiving commands, e.g., via radio frequency, infrared, or other signals.

As shown in <FIG> and <FIG>, all of the internal components of the probe <NUM> may be provided in a housing or casing <NUM> such that the probe <NUM> is self-contained. For example, the casing <NUM> may be relatively small and portable, e.g., such that the entire probe <NUM> may be held in a user's hand. Optionally, as shown in <FIG>, the first end 30a of the casing <NUM> may be formed from like or different materials than other portions of the casing <NUM>. For example, the first end 30a may be formed from materials that easily accommodate passage of electromagnetic signals therethrough, e.g., from the transmit antenna <NUM> and/or to the receive antenna <NUM>, without substantial interference. Optionally, the materials may be selected to reduce interference, match impedance, or otherwise facilitate transmitting and receiving signals via the probe <NUM> into and out of a patient's body. In addition or alternatively, if desired, the probe <NUM> may include a handle, finger grips, and/or other features (not shown) to facilitate holding or otherwise manipulating the probe <NUM>.

Alternatively, as shown in <FIG>, a probe instrument <NUM> may be provided that includes a separate controller <NUM> including one or more of the components within a casing remote from a handheld probe <NUM>. For example, the handheld probe <NUM> may include an elongate housing 131a including a tip 131b with one or more antennas <NUM>. The controller <NUM> may include one or more processors for controlling the antenna(s) <NUM>, a display <NUM>, and the like, similar to the previous embodiments. The handheld probe <NUM> may be coupled to the processor(s) in the controller <NUM> by one or more cables <NUM>. For example, an impulse generator, impulse receiver, and/or gate control may be provided within the casing of the controller <NUM> or, optionally, within the housing 131a, if desired. In one embodiment, the cable <NUM> may be removably connectable to a connector (not shown) on the controller <NUM> for electrically coupling the antenna <NUM> of the handheld probe <NUM> to the electronics within the controller <NUM>. Thus, the handheld probe <NUM> may be a disposable, single-use device while the controller <NUM> may be used during multiple procedures by connecting a new handheld probe <NUM> to the controller <NUM>, which may remain out of the surgical field yet remain accessible and/or visible, as desired, as explained further below.

Turning to <FIG>, the localization system <NUM> of <FIG> may be used during a medical procedure, for example, in a breast biopsy or lumpectomy procedure, e.g., to facilitate localization of a lesion or other target tissue region <NUM> and/or to facilitate dissection and/or removal of a specimen from a breast <NUM> or other body structure. It should be noted that, although the system <NUM> is described as being particularly useful in localization of breast lesions, the system <NUM> can also be used in localization of other objects in other areas of the body, e.g., as described elsewhere herein.

Before the procedure, a target tissue region, e.g., a tumor or other lesion, may be identified using conventional methods. For example, as shown in <FIG>, a lesion <NUM> within a breast <NUM> may be identified, e.g., using mammography and/or other imaging, and a decision may be made to remove the lesion <NUM>. The dashed line <NUM> surrounding the tumor <NUM> defines a "clear" margin, e.g., indicating the size and shape of a desired tissue specimen <NUM> that is to be removed during the procedure. For example, the margin <NUM> may be selected to ensure that the remaining tissue after removing the specimen <NUM> is substantially clear of cancerous or other undesired cells. In an exemplary embodiment, the distance between the outer boundaries of the lesion <NUM> and the outer edges or margin <NUM> of the tissue specimen <NUM> may be between about one and ten millimeters (<NUM>-<NUM>), e.g., at least about two millimeters (<NUM>) or at least about one centimeter (<NUM>).

Referring to <FIG> and <FIG>, the localization wire <NUM> may be introduced percutaneously through tissue <NUM>, e.g., from the patient's skin <NUM> through intervening tissue until the target <NUM> is positioned within the lesion <NUM>. In an exemplary embodiment, the localization wire <NUM> may be introduced through a delivery sheath (not shown), which may be placed previously using a needle and/or dilator (also not shown), similar to the cannula <NUM> described with reference to <FIG> elsewhere herein. For example, a cannula or delivery sheath having a sharpened tip may be penetrated through the skin <NUM> and intervening tissue <NUM> into the lesion <NUM>, e.g., using ultrasound or x-ray imaging for guidance, and then the localization wire <NUM> may be advanced through the cannula. Alternatively, a needle having a sharpened tip may be advanced through tissue and then a delivery sheath may be advanced over the needle (not shown), e.g., along with a dilator between the needle and delivery sheath. Once the delivery sheath is positioned such that it extends from the skin <NUM> to the lesion <NUM>, the needle and any dilator may be removed. The distal end 22b of the localization wire <NUM> may then be advanced through the delivery sheath until the target <NUM> is positioned within the lesion <NUM>, whereupon the delivery sheath may be removed. Optionally, the localization wire <NUM> may include one or more markers (not shown) on the distal end, e.g., radiopaque or echogenic markers, on or adjacent the target <NUM>, to facilitate imaging the target <NUM> and/or distal end 22b of the localization wire <NUM>. External imaging may then be used during and/or after introduction of the localization wire <NUM> to ensure that the target <NUM> is properly positioned within the lesion <NUM>.

If the localization wire <NUM> includes anchoring element(s), such as barbs <NUM>, the barbs <NUM> may be compressed inwardly when the localization wire <NUM> is advanced through the delivery sheath. Once the target <NUM> is positioned within the lesion <NUM>, the delivery sheath may be withdrawn, whereupon the barbs <NUM> may resiliently expand outwardly into the adjacent tissue. Thus, the barbs <NUM> on the distal end 22b of the shaft <NUM> may anchor the localization wire <NUM> relative to the lesion <NUM>, e.g., such the target <NUM> may be substantially secured in a fixed position within the lesion <NUM>. In addition or alternatively, a bandage, tape, and the like (not shown) may be used to secure the proximal end 22a of the localization wire 22a to the patient's skin <NUM>, e.g., to prevent migration of the localization wire <NUM>.

After the localization wire <NUM> is correctly positioned and/or secured, the first end 30a of the probe <NUM> may be placed adjacent or in contact with the patient's skin <NUM>, e.g., generally above the lesion <NUM>, and/or otherwise aimed generally towards the target <NUM>, and activated, as shown in <FIG>. The transmit antenna <NUM> (not shown, see <FIG>) of the probe <NUM> may emit electromagnetic signals <NUM> that travel through the tissue <NUM> and are reflected off of the target <NUM>. The signals <NUM> may be reflected back to the receive antenna <NUM> (not shown, see <FIG>) in the probe <NUM>. The probe <NUM> may then determine a spatial relationship between the target <NUM> and the first end 30a of the probe <NUM>, e.g., a distance <NUM> between the target <NUM> and the probe <NUM> (and the patient's skin <NUM> if contacted by the first end 30a of the probe <NUM>), e.g., based on the distance traveled by the signals <NUM>, passage of time between transmission of signals <NUM> and reception of reflected signals <NUM>, and the like. Optionally, the probe <NUM> may also determine a relative angle between the target <NUM> and the first end 30a, e.g., to facilitate determining a proper direction of dissection.

In one embodiment, the micro-controller 36a (not shown, see <FIG>) of the probe <NUM> may filter or otherwise analyze received signals to identify the target <NUM>, e.g., based on recognition of the size, shape, or other aspects of the target <NUM>. Thus, the micro-controller 36a may automatically be able to identify the target <NUM> and distinguish it from other structures that may be present in the patient's body. Alternatively, the micro-controller 36a may simply identify any objects reflecting signals back to the probe <NUM>, which presumably would identify the target <NUM>. For example, the micro-controller 36a may calculate the distance <NUM> and/or an angle relative to an axis extending orthogonally from the first end 30a of the probe <NUM>, and display this spatial information on the display <NUM>. This information may facilitate localizing the target <NUM>, and consequently the lesion <NUM>, which may provide guidance to a surgeon dissecting tissue overlying the lesion <NUM>, e.g., by providing a direction and depth of dissection to access the target tissue region including the lesion <NUM>.

In addition or alternatively, other information may be displayed on the display <NUM> if desired. For example, the display <NUM> may provide a distance <NUM> between the target <NUM> and the outer margin <NUM> of the target tissue specimen <NUM>, which may facilitate defining the targeted size and shape of the tissue specimen <NUM> to be removed. To determine the distance <NUM>, the probe <NUM> may automatically subtract a predetermined distance between the desired margin <NUM> and the target <NUM>, e.g., based on preset parameters programmed into the processor <NUM> of the probe <NUM> or based on dimensions provided to the micro-controller 36a by the user immediately before the procedure, e.g., via user controls <NUM> (not shown, see <FIG>).

Optionally, with continued reference to <FIG>, the probe <NUM> may be positioned at several locations against or otherwise adjacent the skin <NUM> and spatial information obtained, if desired. Such information may facilitate the surgeon determining an optimal approach path for dissection, e.g., the shortest path to the lesion <NUM>, or otherwise help orient the surgeon relative to the lesion <NUM> in three dimensions. After the distance <NUM> between the patient's skin <NUM> and the target <NUM> from a desired location on the skin <NUM> is determined, the tissue <NUM> may be dissected to reach the predetermined outer edge <NUM> of the tissue specimen <NUM>, as shown in <FIG>. For example, an incision may be made in the patient's skin <NUM> at the location where the probe <NUM> was placed and the intervening tissue dissected using known methods until the depth corresponding to the margin <NUM> is achieved. Optionally, at any time during dissection, the probe <NUM> may be placed against or adjacent the exposed tissue and spatial information obtained to confirm the approach and/or depth of dissection.

With continued reference to <FIG>, if desired, once the surgeon believes the desired margin <NUM> has been reached, another length measurement may be taken with the probe <NUM> to verify that the predetermined distance <NUM> to the target <NUM> has been reached. For example, the first end 30a of the probe <NUM> may be placed in contact with the bottom surface of the dissected tissue area, signals <NUM> may be transmitted by the transmit antenna <NUM>, and signals <NUM> may be received by the receive antenna <NUM> in order for the probe <NUM> to determine the distance between the bottom surface of the dissected tissue area and the target <NUM>. After verifying that the desired margin <NUM> of the tissue specimen <NUM> has been reached, the tissue specimen <NUM> may be excised or otherwise removed using conventional lumpectomy procedures with the target <NUM> remaining within the removed specimen <NUM>. If desired, the target <NUM> may be separated from the shaft <NUM> to facilitate removal of the specimen <NUM>, e.g., by cutting the distal end 22b of the shaft <NUM>, by disconnecting any connectors (not shown) between the shaft <NUM> and target <NUM>, and the like.

Turning to <FIG>, if desired, the probe <NUM> may be used to analyze the excised tissue specimen <NUM>, e.g., to confirm that the desired margin <NUM> has been achieved around the target <NUM>, and consequently around the lesion <NUM>. As shown, transmit signals <NUM> are transmitted by the probe <NUM> and signals <NUM> are reflected off the target <NUM> and received by the probe <NUM>, whereupon the probe <NUM> may determine and display the distance <NUM> and/or any other spatial information. In this manner, it can be verified that the predetermined tissue margin has been achieved.

Turning to <FIG>, another exemplary embodiment of a system <NUM> for localizing a lesion or other tissue structure, e.g., a plurality of non-palpable lesions <NUM>, is shown that includes a probe <NUM> and a plurality of implantable markers or targets <NUM>. The probe <NUM> may be a portable device capable of transmitting electromagnetic signals and receiving reflected signals, similar to the embodiments described elsewhere herein.

The markers <NUM> may include a plurality of implantable elements sized for introduction through tissue into a region surrounding the lesion <NUM>. For example, the markers <NUM> may be formed as a plurality of strips, cylinders, helixes, spheres, and the like, e.g., having features to enhance reflection of electromagnetic signals transmitted by the probe <NUM>, similar to the target <NUM> described above with reference to <FIG> and/or the markers described further elsewhere herein, e.g., with reference to <FIG>, <FIG>.

As shown in <FIG>, the markers <NUM> may be elongate strips, e.g., rectangular or other shaped markers having a length between about half to four millimeters (<NUM>-<NUM>), a width between about half and two millimeters (<NUM>-<NUM>), and a thickness between about half and three millimeters (<NUM>-<NUM>). The markers <NUM> may be formed from metal or other material that may enhance detection by the probe <NUM>, e.g., having a desired dielectric constant. In addition or alternatively, the markers <NUM> may be formed from bioabsorbable material, e.g., such that the markers <NUM> may be implanted within tissue and then dissolved or otherwise absorbed by the tissue over time, e.g., over several days, weeks, or months.

Optionally, the markers <NUM> may be formed from radiopaque material, radioactive material, and/or echogenic material, which may facilitate imaging or otherwise monitoring the markers <NUM>, e.g., during introduction, after placement during a procedure, or afterwards if the markers <NUM> remain within the patient's body after the procedure. In addition, if desired, each marker <NUM> may have a surface, shape, and/or additional material feature that may distinguish one or more of the markers from others, as described elsewhere herein. For example, each marker <NUM> may modulate an incident signal from the probe <NUM> in a predetermined manner and/or absorb or reflect a particular electromagnetic signal that is specific to that marker <NUM> and may be used to uniquely identify it.

In addition, as shown in <FIG>, the system <NUM> may also include one or more delivery devices <NUM> for introducing the markers <NUM> into a patient's body. For example, a delivery device <NUM> may be provided that includes a shaft <NUM> including a proximal end 162a and a distal end 162b sized for introduction through tissue into a target tissue region (not shown) and carrying one or more markers <NUM>. The delivery device <NUM> may include a lumen <NUM> extending at least partially between the proximal and distal ends 162a, 162b of the shaft <NUM>, and a pusher member <NUM> slidable within the shaft <NUM> for selectively delivering one or more markers <NUM> successively or otherwise independently from the lumen <NUM>.

As shown, the distal end 162b of the shaft <NUM> may be beveled and/or otherwise sharpened such that the shaft <NUM> may be introduced directly through tissue. Alternatively, the delivery device <NUM> may be introduced through a cannula, sheath, or other tubular member (not shown) previously placed through tissue, e.g., as described elsewhere herein. Optionally, the distal end 162b may include a band or other feature, e.g., formed from radiopaque, echogenic, or other material, which may facilitate monitoring the distal end 162b during introduction, e.g., using fluoroscopy, ultrasound, electromagnetic signals, and the like.

As shown, the pusher member <NUM> includes a piston or other element (not shown) disposed within the lumen <NUM> adjacent the marker(s) <NUM> and a plunger or other actuator <NUM> coupled to the piston for advancing the piston to push the marker(s) <NUM> from the lumen <NUM>. As shown, the plunger <NUM> may be manually advanced to deliver one or more markers <NUM> successively from the lumen <NUM>. Alternatively, a trigger device or other automated actuator (not shown) may be provided on the proximal end 162b of the shaft <NUM>, which may advance the piston sufficiently with each activation, e.g., to delivery an individual marker <NUM> from the distal end 162b.

Returning to <FIG>, an exemplary method is shown for using the markers <NUM> and probe <NUM> to localize a lesion or other target tissue region <NUM> within a breast <NUM> or other tissue structure. As shown in <FIG> and <FIG>, the markers <NUM> may be implanted within the tissue <NUM> to delineate a desired margin or volume <NUM> of a tissue specimen <NUM> to be excised. For example, the shaft <NUM> of the delivery device <NUM> may be inserted percutaneously through the patient's skin <NUM>, through any intervening tissue <NUM>, and the distal end 162b positioned within or around the lesion <NUM>, e.g., using external imaging to guide the distal end 162b to a desired location. Once in position, the plunger <NUM> may be advanced (or the shaft <NUM> withdrawn relative to the plunger <NUM>) to deliver a marker <NUM> into the tissue. The delivery device <NUM> may be advanced further to another location and/or removed entirely from the breast <NUM> and reintroduced through another location of the skin <NUM> into the target tissue region, e.g., to deliver one or more additional markers <NUM>.

Alternatively, the delivery device <NUM> may carry only a single marker <NUM>, and multiple delivery devices (not shown) may be provided for delivering each of the markers <NUM>. In addition or alternatively, a stereotactic device (not shown) may be used, e.g., to introduce one or multiple delivery devices into the patient's body in a desired three-dimensional array or other arrangement for localizing the lesion <NUM>. In a further alternative, the markers <NUM> may be replaced with multiple localization wires, similar to wire <NUM>, one or more catheters (not shown) which may be delivered sequentially, simultaneously, and the like. Optionally, the catheter(s), wire(s), or other devices may be expandable, e.g., at a distal region (not shown) to facilitate dilating and/or identifying a specimen volume or region.

In the exemplary embodiment shown in <FIG> and <FIG>, the markers <NUM> surround a group of non-palpable lesions <NUM>, e.g., before or during a procedure to remove a specimen volume surrounding the lesions <NUM>. The distance <NUM> between the outer edge <NUM> of the tissue specimen <NUM> and the lesions <NUM> may be selected to ensure that the volume of tissue removed is sufficient to ensure clear margins, similar to the methods described above.

As shown in <FIG>, after the markers <NUM> have been implanted, the probe <NUM> may be placed against or otherwise adjacent the patient's skin <NUM> (e.g., it may be unnecessary to contact the patient's skin <NUM> with the probe <NUM> to transmit and receive signals into and from the tissue <NUM>), and the probe <NUM> may be used to determine the distance <NUM> (and/or other spatial information) between the probe <NUM> and the markers <NUM>, similar to the previous embodiments. In particular, the signals <NUM> emitted by the probe <NUM> may be received at the markers <NUM> and reflected back to a receiver in the probe <NUM> as signals <NUM>, and the probe <NUM> may use the signals to determine the distance <NUM> between the patient's skin <NUM> and the markers <NUM>.

The tissue <NUM> surrounding the lesions <NUM> may then be dissected until one of the markers <NUM> is encountered, as shown in <FIG>. At this point, another measurement may be taken with the probe <NUM> to ensure proper dissection depth. The probe <NUM> may then be repositioned, as shown in phantom in <FIG>, to locate another one of the markers <NUM> around the periphery <NUM> of the tissue specimen <NUM>. The resulting distance measurements may be used to determine a desired margin volume for excision around the lesions <NUM>. This process may be repeated as often as desired to facilitate measuring the desired margin based on the distance to the markers <NUM> during excision of the tissue specimen <NUM> around the lesions <NUM>. The tissue specimen <NUM> may include the markers <NUM> therein such that all of the markers <NUM> are removed with the tissue specimen <NUM>. Alternatively, the desired margin may be defined within the markers <NUM> such that the markers <NUM> remain within the breast after the tissue specimen <NUM> is removed. In this alternative, the markers <NUM> may be bioabsorbable or may be inert and remain indefinitely within the patient's breast <NUM>.

Turning to <FIG>, another exemplary system and method are shown for localizing one or more lesions <NUM> within a breast <NUM> and/or removing a tissue specimen <NUM> (shown in <FIG>) including the lesion(s) <NUM>. Similar to the previous embodiments, the system includes one or more markers <NUM> and a probe instrument <NUM>, which may facilitate localizing the lesion(s) <NUM> and/or ensuring desired margins are achieved for the tissue specimen <NUM> removed from the breast <NUM>. The probe instrument <NUM> includes a handheld probe <NUM> coupled to a processor <NUM> including one or more processors for controlling operation of the probe <NUM>, as described above. Also as described above, the handheld probe <NUM> includes an elongate housing 131a including one or more antennas <NUM> on or within a tip 131b on one end of the probe <NUM> that may be placed against the skin <NUM> or other tissue and/or otherwise oriented generally towards the marker <NUM> and/or lesion(s) <NUM>.

The processor <NUM> may include one or more processors for controlling the antenna(s) <NUM>, a display <NUM>, and the like, similar to the previous embodiments. The handheld probe <NUM> may be coupled to the processor <NUM> by one or more cables <NUM>. For example, an impulse generator, impulse receiver, and/or gate control may be provided within the processor <NUM>, which may be controlled to emit and receive signals via the antenna(s) <NUM>.

Optionally, as shown in <FIG>, the handheld probe <NUM> may include a dissecting feature <NUM>, e.g., extending from the tip 131b of the housing 131a. In one embodiment, the dissecting feature <NUM> may be a relatively flat blunt dissector fixed to the tip 131b of the probe <NUM>, e.g., having a length of about ten to fifty millimeters (<NUM>-<NUM>) and/or a width of about one to ten millimeters (<NUM>-<NUM>). Alternatively, the dissecting feature <NUM> may be retractable, e.g., such that the dissecting feature <NUM> may be initially retracted within the housing 131a, but may be selectively deployed when desired to dissect layers of tissue to access tissue adjacent the marker <NUM>. In a further alternative, the dissecting feature <NUM> may include a sharpened blade or edge, which may facilitate cutting through the patient's skin <NUM> and/or underlying layers of tissue <NUM>.

Initially, as shown in <FIG>, during use, one or more markers <NUM> may be implanted within the target tissue region, e.g., using the markers and/or methods described elsewhere herein. The probe <NUM> may be coupled to the processor <NUM>, e.g., by cable <NUM>, and the tip 131b placed against the skin <NUM>. The probe <NUM> may be activated, e.g., to obtain an initial distance measurement from the tip 131b of the probe <NUM> to the marker <NUM> using the antenna(s) <NUM>, thereby providing an approximate distance to the lesion(s) <NUM>. The distance measurement may be displayed on the display <NUM> of the processor <NUM>, e.g., as shown in <FIG>, and/or otherwise provided to the user. In addition or alternatively, as described above, a speaker may provide the distance measurement, e.g., using a synthesized voice, one or more tones identifying corresponding distances, and the like, to identify the distance. For example, the processor <NUM> may analyze the received signals to determine the actual distance from the tip 131b of the probe <NUM> to the marker <NUM>, and may provide the actual measurement via the speaker. Alternatively, the speaker may provide a tone corresponding to a predetermined threshold, e.g., a first tone for a first threshold distance, a second tone or multiple tones for a second, closer distance, and the like, thereby indicating to the user that they are getting closer to the marker <NUM>.

As shown in <FIG>, with the probe <NUM> on a first side of the breast <NUM>, a measurement L1 is obtained, while with the probe <NUM>' placed on a second opposite side of the breast <NUM>, a measurement L2 is obtained, which is greater than L1. With this information, the physician may decide to initiate dissection on the first side since it provides a shorter path requiring less tissue dissection than a path initiated from the second side, as shown in <FIG>.

Turning to <FIG>, the probe <NUM> may be used to identify a desired margin L3 around the marker <NUM> and consequently around the lesion(s) <NUM>. For example, if a desired margin L3 of one centimeter (<NUM>) is desired, the probe <NUM> may be display or otherwise provide the actual distance L1 from the probe <NUM> to the marker, as shown on the display <NUM>, thereby indicating that the probe <NUM> remains outside the margin L3. Alternatively, if the processor <NUM> knows the desired margin L3, the display <NUM> may provide the difference between the actual distance L1 and the desired margin L3 (i.e., L1-L3), thereby informing the physician of the depth of dissection necessary to attain the desired margin.

Optionally, as shown in <FIG>, if the probe <NUM> includes the blunt dissector <NUM>, the blunt dissector <NUM> may be deployed from the tip 131b of the probe <NUM> (if not permanently deployed) and advanced through the tissue <NUM> towards the marker <NUM>, e.g., until the desired margin L3 is attained. The probe <NUM> may then be manipulated to dissect tissue around the marker <NUM> using the blunt dissector <NUM> and/or using one or more additional dissectors, scalpels, or other tools (not shown).

As shown in <FIG>, a tissue specimen <NUM> has been removed from the breast <NUM> that includes the marker <NUM> and the lesion(s) <NUM> therein. Optionally, the probe <NUM> may then be used to confirm that the desired margin L3 was achieved around the marker <NUM>, thereby providing confirmation that sufficient tissue has been removed from the breast <NUM>, similar to the previous embodiments.

Turning to <FIG>, still another embodiment of a system is shown that includes one or more markers <NUM>, a probe <NUM> including a finger cot 231a carrying one or more antennas <NUM>, and a processor <NUM> coupled to the antenna(s) <NUM>, e.g., by cable <NUM>. The finger cot 231a may be a flexible sleeve, e.g., including an open end 231b into which a finger <NUM> may be inserted, a closed end 231c, and having sufficient length to be securely received over the finger <NUM>. For example, the finger cot 231a may be formed from elastic material, such as a relatively thin layer of latex, natural or synthetic rubber, and the like, e.g., similar to surgical or examination gloves, having sufficient flexibility to expand to accommodate receiving the finger <NUM> while compressing inwardly to prevent the finger cot from 231a sliding off the finger <NUM> during use.

The antenna(s) <NUM> may be provided adjacent the closed end 231c, as shown. For example, the antenna(s) <NUM> may include a transmit antenna and a receive antenna (not shown), similar to the previous embodiments, provided within a casing. The casing may be attached to the finger cot 231a, e.g., adjacent the closed end 231c, for example, by bonding with adhesive, fusing, one or more overlying bands (not shown), and the like.

The processor <NUM> may include one or more components for operating the antenna(s) <NUM> and/or processing signals received from the antenna(s) <NUM>, e.g., coupled to the antenna(s) <NUM> by cable <NUM> and including display <NUM>, similar to the previous embodiments. In the embodiment shown, the processor <NUM> includes one or more clips 239a, straps, belts, clamps, or other features (not shown) that allow the processor <NUM> to be removably secured to the arm of a user whose finger is inserted into the finger cot 231a. For example, the clips 239a may be curved to extend partially around a user's forearm, and the clips 239a may be sufficiently flexible to open them to receive an arm therein and then resiliently close to engage at least partially around the arm. Alternatively, the processor <NUM> may be provided in a casing (not shown) that may be placed remotely from the patient and/or user, e.g., similar to the processor <NUM> described above.

With additional reference to <FIG> and <FIG>, during use, a physician or other user may insert one of their fingers <NUM>, e.g., their index finger or thumb, into the finger cot 231a, and the processor <NUM> may be activated to send and receive signals via the antenna(s) <NUM>, similar to the previous embodiments.

As shown in <FIG>, the finger <NUM> inserted into the finger cot 231a may be placed against the patient's skin <NUM> and distance measurements obtained to identify the distance to the marker <NUM>. As the tissue overlying the marker <NUM> is dissected, the user may insert the finger <NUM> into the path created, as shown in <FIG>, thereby providing direct feedback to the user of the location of the marker <NUM>, and consequently, the lesion(s) <NUM>, relative to the finger <NUM>. Thus, this embodiment of the probe <NUM> may provide tactile feedback as well as distance measurements, which may facilitate dissection and/or removal of a tissue specimen <NUM> including the marker <NUM> and lesion(s) <NUM> therein. For example, as shown in <FIG>, an initial distance measurement L1 may be obtained informing the user of the depth of dissection needed, while, as shown in <FIG>, a distance measurement L2 may be obtained (corresponding to the desired margin), thereby informing the user that sufficient dissection has been achieved and the tissue specimen <NUM> may be isolated and removed, similar to the previous embodiments.

Turning to <FIG>, still another system is shown for localizing and/or accessing a target tissue region, e.g., including one or more lesions <NUM>. Generally, the system includes a probe instrument <NUM>, including a handheld probe <NUM> coupled to a processor <NUM>, similar to the previous embodiments. For example, the probe <NUM> includes one or more antennas <NUM>, and the processor <NUM> includes a display <NUM>.

In addition, the system includes a cannula or other tubular member <NUM> that includes a proximal end <NUM>, distal end <NUM>, and a lumen <NUM> extending therebetween. The cannula <NUM> may be a substantially rigid tubular body having a size such that the probe <NUM> may be received within the lumen <NUM>, as shown in <FIG>. As shown, the distal end <NUM> may be beveled, sharpened, and/or otherwise formed to facilitate advancement directly through tissue. Alternatively, the distal end <NUM> may be tapered and/or rounded (not shown), e.g., such that the cannula <NUM> may be advanced over a needle (not shown) either before or after the needle has been introduced into the tissue <NUM>, similar to the previous embodiments.

With reference to <FIG>, before use, the probe <NUM> may be inserted into the lumen <NUM> of the cannula <NUM>, e.g., such that the antenna(s) <NUM> are disposed immediately adjacent the distal end <NUM> of the cannula <NUM>. Optionally, the cannula <NUM> and/or probe <NUM> may include one or more connectors (not shown) for releasably securing the probe <NUM> relative to the cannula <NUM>, e.g., to maintain the antenna(s) <NUM> adjacent the distal end <NUM>, while allowing the probe <NUM> to be removed when desired. In addition or alternatively, the cannula <NUM> may include one or more seals (not shown), e.g., within the proximal end <NUM> and/or distal end <NUM>, to provide a substantially fluid-tight seal when the probe <NUM> is disposed within the lumen <NUM> and/or when the probe <NUM> is removed. For example, a hemostatic seal (not shown) may be provided in the proximal end <NUM> that may provide a seal to prevent fluid flow through the lumen <NUM>, yet accommodate receiving the probe <NUM> or other instruments (not shown) therethrough.

Turning to <FIG>, during use, with the probe <NUM> activated and within the cannula <NUM>, the distal end <NUM> of the cannula <NUM> may be inserted through the patient's skin <NUM> and tissue <NUM> towards the marker <NUM>. As shown, the probe <NUM> may transmit signals <NUM> and the display <NUM> of the processor <NUM> may provide a distance measurement L1 or other indication of the relative location of the marker <NUM> to the antenna(s) <NUM> based on the reflected signals received by the antenna(s) <NUM>, and consequently, relative to the distal end <NUM> of the cannula <NUM>. Thus, the depth of penetration and/or direction of advancement of the cannula <NUM> may be adjusted based upon the information provided by the probe <NUM> and processor <NUM>. For example, as shown in <FIG>, the cannula <NUM> may be advanced until a desired distance L2 is achieved, thereby placing the distal end <NUM> a desired distance away from the marker <NUM>, e.g., within a target tissue region adjacent the lesion(s) <NUM>.

Turning to <FIG>, with the distal end <NUM> of the cannula <NUM> placed at a desired location relative to the lesion(s) <NUM>, the probe <NUM> may be removed, leaving the cannula <NUM> in place, as shown. The cannula <NUM> may thereby provide a passage for accessing the target tissue region, e.g., to perform one or more diagnostic and/or therapeutic procedure. For example, a needle or other tool (not shown) may be advanced through the lumen <NUM> of the cannula to perform a biopsy and/or to deliver fluids or other diagnostic or therapeutic material into the target tissue region. In addition or alternatively, one or more instruments (not shown) may be introduced through the cannula <NUM> for removing a tissue specimen, e.g., including the lesion(s) <NUM>, for delivering radiation therapy, and/or other procedures. When access is no longer needed, the cannula <NUM> may simply be removed. Alternatively, if it is desired to relocate the cannula <NUM> during a procedure, the probe <NUM> may be reintroduced into the lumen <NUM> and the cannula <NUM> relocated within the tissue with the probe <NUM> providing additional guidance.

In <FIG>, markers <NUM> are shown, which may be implanted or otherwise placed within the tissue <NUM>, e.g., within or otherwise adjacent the lesion(s) <NUM>, using methods similar to those described above. As shown, the markers <NUM> are generally elongate bodies including relatively narrow middle stem portions between bulbous ends. The markers <NUM> may be formed from desired materials and/or may include surface features similar to other markers herein, which may facilitate localization of the markers <NUM> and/or distinguishing markers from one another.

Turning to <FIG>, additional embodiments of markers are shown that may be used in any of the systems and methods described herein. For example, turning to <FIG>, a first exemplary marker <NUM> is shown that includes a core wire <NUM> carrying a plurality of beads or segments <NUM>. The core wire <NUM> may be an elongate member, e.g., a solid or hollow structure having a diameter or other maximum cross-section between about half and two millimeters (<NUM>-<NUM>) and a length between about one and ten millimeters (<NUM>-<NUM>). The core wire <NUM> may be formed from elastic or superelastic material and/or from shape memory material, e.g., stainless steel, Nitinol, and the like, such that the core wire <NUM> is biased to a predetermined shape when deployed within tissue, as explained further below. Alternatively, the core wire <NUM> may be substantially rigid such that the marker <NUM> remains in a fixed shape, e.g., linear or curved, as described further below.

As best seen in <FIG>, the beads <NUM> may include a plurality of individual annular bodies, e.g., each defining a portion of a generally cylindrical or spherical shape. The beads <NUM> may be formed from desired materials similar to the previous embodiments, e.g., metals, such as stainless steel, Nitinol, titanium, and the like, plastic materials, or composite materials. The beads <NUM> may be formed by injection molding, casting, machining, cutting, grinding base material, and the like. In addition, a desired finish may be applied to the beads <NUM>, e.g., by sand blasting, etching, vapor deposition, and the like.

As best seen in <FIG>, each bead <NUM> may include a passage <NUM> therethrough for receiving the core wire <NUM> (not shown, see, e.g., <FIG>) therethrough. The beads <NUM> may include shapes and/or surface features to allow the beads <NUM> to be nested at least partially adjacent one another when secured onto the core wire <NUM>, yet allow the marker <NUM> to change shape, e.g., as the core wire <NUM> changes shape. In addition, the beads <NUM> include surface geometries to enhance reflection of electromagnetic waves, e.g., radar, for example, including one or more recesses around a periphery of the beads that include multiple surfaces with adjacent surfaces defining abrupt angles, e.g., between about forty five and one hundred thirty five degrees (<NUM>-<NUM>°), or, e.g., about ninety degrees (<NUM>°). For example, as best seen in <FIG>, each bead <NUM> may include a first convex or bulbous end 324a and a second concave end 324b including flat surfaces 324d. As shown in <FIG>, adjacent beads <NUM>' may define recesses 324c' between the flat surfaces 324d' on the concave end 324b' of a first bead <NUM> and a surface 324e' on the bulbous end 324a' of the adjacent bead <NUM>. ' The surfaces 324d' and 324e' may define abrupt corners therebetween, which may enhance detection using radar, e.g., defining angles of about ninety degrees (<NUM>°).

Optionally, as shown in <FIG>, the beads <NUM>' may include a desired surface finish 324f' intended to customize reflected signals generated when electromagnetic signals strike the surfaces of the beads <NUM>. ' For example, the surface finish 324f' may include a plurality of pores or dimples formed in the beads <NUM>' and having a desired diameter and/or depth. As explained above, the probes and processors described elsewhere herein may analyze such reflected signals to uniquely identify a particular marker, e.g., when multiple markers are implanted or otherwise placed within a patient's body.

Returning to <FIG>, during assembly, a plurality of beads <NUM> may be placed over and secured to the core wire <NUM> to provide a finished marker <NUM>. For example, the core wire <NUM> may be inserted successively through the passages <NUM> in the beads <NUM> until beads <NUM> extend substantially between the ends of the core wire <NUM>. The beads <NUM> may be secured to the core wire <NUM>, e.g., by crimping individual beads <NUM> onto the core wire <NUM>, crimping or otherwise expanding the ends of the core wire <NUM> after sliding on sufficient beads <NUM>, bonding with adhesive, fusing, and the like. Thus, the beads <NUM> may be substantially permanently attached to the core wire <NUM> such that the beads <NUM> cannot move or the beads <NUM> may be free floating on the core wire <NUM>, e.g., which may facilitate bending or otherwise shaping the core wire <NUM>, and consequently the marker <NUM>.

Alternatively, the marker <NUM> may be formed from a single piece of material, e.g., such that the shapes and surfaces defined by the beads <NUM> shown in <FIG> are formed in the workpiece. In this alternative, the core wire <NUM> may be eliminated, or a passage may be formed through the workpiece for receiving the core wire <NUM>.

In one embodiment, the marker <NUM> may define a substantially fixed shape, e.g., a linear shape as shown in <FIG>, or a curvilinear shape, as shown in <FIG>. For example, the core wire <NUM> of the marker <NUM> may be sufficiently flexible such that the marker <NUM> may be straightened, e.g., to facilitate loading the marker <NUM> into a delivery device and/or otherwise delivering the marker <NUM>, yet the marker <NUM> may be biased to a curvilinear or other nonlinear shape.

As shown in <FIG>, the marker <NUM> may be biased to assume a wave configuration, e.g., a serpentine or other curved shape lying within a plane. For example, the core wire <NUM> may be formed from elastic or superelastic material that is shape set such that the core wire <NUM> is biased to the wave configuration, yet may be resiliently straightened to a linear configuration. The beads <NUM> may be spaced apart or otherwise nested such that the beads <NUM> do not interfere substantially with the transformation of the core wire <NUM> between the linear and wave configurations, e.g., to facilitate loading the marker <NUM> into a delivery device and/or introducing the marker <NUM> into a body.

Alternatively, as shown in <FIG>, a marker <NUM>'" may be provided that is biased to assume a tapered helical shape, e.g., including a relatively wide intermediate region 320a‴ between tapered end regions 320b. ‴ Another alternative embodiment of a marker <NUM>"" is shown in <FIG> that is biased to assume a substantially uniform diameter helical shape. One of the advantages of markers <NUM>,‴ <NUM>"" is that they may provide a relatively constant and/or consistent Radar Cross Section ("RCS") regardless of the reflective angle and/or position of the markers <NUM>,'" <NUM>"" relative to the antenna(s) of the probe (not shown). For example, even when the markers <NUM>,'" <NUM>"" are viewed along the helix axis, e.g., as viewed in <FIG>, the markers <NUM>,'" <NUM>"" may provide a RCS substantially similar to when viewed laterally relative to the helical axis, e.g., as viewed in <FIG>.

Optionally, any of the markers described herein may be provided as a passive marker, an active marker, an active reflector, or an active transponder. For example, with reference to <FIG>, the marker <NUM> may simply be a "passive reflector," i.e., the marker <NUM> may simply reflect incident waves or signals striking the marker <NUM>. The incident signals may be reflected off of the various surfaces and/or edges of the marker <NUM>, e.g., thereby providing reflected waves or signals that may be detected by a probe, as described further elsewhere herein. One disadvantage of a passive marker is that the Radar Cross Section (RCS) may change based on the aspect angle of the antenna of the probe and the marker <NUM>, which may cause changes in the strength of the returned signal reflected from the marker <NUM>.

Alternatively, the marker <NUM> may include one or more features to provide an "active reflector," i.e., a marker <NUM> that includes one or more electronic circuits that modulate signals striking the marker <NUM> in a predetermined manner without adding external energy or power to the reflected signals. Such a marker may include an active reflector radio element that includes a modulated dipole or other type of active reflector antenna, e.g., including one or more very low power diodes and/or FET transistors that require very little current to operate. The active reflector may provide a substantially unique radar signal signature in an embedded tissue environment that may be detected and identified by a probe. In addition, the active reflector may provide a relatively larger signal return to the probe, e.g., thereby maintaining a target RCS regardless of antenna aspect.

For example, the marker <NUM> may include one or more circuits or other elements (not shown) coupled to or embedded in the marker <NUM> that may modulate incident waves or signals from the probe. In an exemplary embodiment, a nanoscale semiconductor chip may be carried by the marker <NUM> that does not include its own energy source and therefore merely processes and modulates the signals when they are received and reflected off the marker <NUM>. Exemplary embodiments of active reflectors that may be provided on a marker are disclosed in <CIT>.

<FIG> show an example of modulation of a reflected signal B relative to an incident signal A that may be achieved using an active reflector. Incident signal A may represent waves or signals transmitted by a probe (not shown), such as any of those described elsewhere herein. As shown in <FIG>, the incident signal A may strike and be reflected off of a surface, e.g., of any of the markers described herein, resulting in a reflected signal B. With a passive reflector, the surface of the marker may simply reflect the incident signal A, and therefore the reflected signal B may have similar properties, e.g., bandwidth, phase, and the like, as the incident signal A.

In contrast, with an active reflector, the marker may modulate the incident signal A in a predetermined manner, for example, to change the frequency and/or phase of the reflected signal B. For example, as shown in <FIG>, the circuit on the marker may change an ultrawide broadband radar incident signal A into a relatively narrow band reflected signal B, e.g., between about one and ten GigaHertz (<NUM>-<NUM>), that also includes a predetermined phase shift. The relatively narrow band reflected signal B may enhance the RCS of the marker and thereby enhance detection by the probe.

In addition, as shown in <FIG>, the phase of the reflected signal B has been modulated by ninety degrees (<NUM>°) relative to the incident signal A. If the marker is unique in this phase shift, the phase shift may facilitate the probe identifying and distinguishing the marker from other structures, e.g., other markers having a different phase shift, tissue structures, and the like. For example, if multiple markers are to be implanted in a patient's body, each marker's circuit may be configured to impose a different phase shift (e.g., +<NUM>°, +<NUM>°, -<NUM>°, and the like) and/or bandwidth in the reflected signal. Thus, the probe may be able to easily identify and distinguish the markers from each other and/or from other structures in the patient's body.

One of the advantages of active reflectors is that the circuit does not require its own power source. Thus, the size of the circuit may be substantially reduced and, if desired, the marker may be implanted within a patient's body for an extended or even indefinite period of time, yet the marker may respond to signals from a probe to facilitate locating and/or identifying the marker.

In a further alternative, an "active marker" may be provided that includes one or more features that generate detectable energy in response to an excitation energy reference. Examples of such active markers are disclosed in <CIT>.

In still a further alternative, an active transponder may be provided, e.g., that retransmits or "transponds" the MIR probe's energy providing for a uniqueness of radar signal signature in an embedded tissue environment. The active transponder may include one or more electronic circuits embedded in or carried by the marker and including an internal energy source, e.g., one or more batteries, capacitors, and the like. In an exemplary embodiment, the active transponder may include a microwave receiver and/or transmitter, a data processing and storage element, and a modulation system for the returned signal. The active transponder may generate microwave energy in response to excitation microwave energy emitted by the probe, e.g., to provide a larger signal return to the probe than would be possible with only a passive marker. For example, the marker may generate RF energy including formatted data in response to a unique radar signature and/or frequency from the probe. In an exemplary embodiment, the active transponder may be quadrature modulated to emit a single side band ("SSB") signal in either the Upper Sideband Band ("USB") or the Lower Sideband ("LSB") of the MIR radar. Such a transponder may provide the possibility of mult-channel operations across the RF spectrum.

Turning to <FIG>, a delivery device <NUM> may be provided that includes a shaft <NUM> including a proximal end 262a and a distal end 262b sized for introduction through tissue into a target tissue region, e.g., within breast <NUM>, and carrying a marker <NUM> (or optionally multiple markers, not shown). The delivery device <NUM> may include a lumen <NUM> extending between the proximal and distal ends 262a, 262b of the shaft <NUM>, and a pusher member <NUM> slidable within the shaft <NUM> for delivering the marker <NUM> of <FIG> from the lumen <NUM>. As shown, the distal end 262b of the shaft <NUM> may be beveled and/or otherwise sharpened such that the shaft <NUM> may be introduced directly through tissue. Alternatively, the delivery device <NUM> may be introduced through a cannula, sheath, or other tubular member (not shown) placed through tissue, e.g., as described elsewhere herein. Optionally, the distal end 262b may include a band or other feature, e.g., formed from radiopaque, echogenic, or other material, which may facilitate monitoring the distal end 262b during introduction, also as described elsewhere herein.

As shown in <FIG>, the pusher member <NUM> includes a distal end <NUM> disposed within the lumen <NUM> adjacent the marker <NUM> and a plunger or other actuator <NUM> for advancing the distal end <NUM> to push the marker <NUM> from the lumen <NUM>. As shown in <FIG>, once the distal end <NUM> of the delivery device <NUM> has been advanced to a desired location within tissue <NUM>, the shaft <NUM> may be retracted relative to the plunger <NUM> to eject the markers <NUM> successively from the lumen <NUM>. Alternatively, a trigger device or other automated actuator (not shown) may be provided on the proximal end 262b of the shaft 262to delivery the marker <NUM> from the distal end 262b.

Turning to <FIG>, an alternative embodiment of a marker <NUM>" is shown that is generally similar to the marker <NUM> shown in <FIG>, e.g., including a core wire <NUM>" carrying a plurality of beads <NUM>. " Unlike the marker <NUM>, however, the core wire <NUM>" is biased to a helical shape, e.g., such that the marker <NUM>" is biased to a helical configuration as shown. Thus, the marker <NUM>" may be straightened, e.g., to facilitate loading into a delivery device, such as the delivery device <NUM> shown in <FIG>, yet may be biased to return resiliently to the helical configuration.

In an alternative embodiment, any of the markers <NUM>, <NUM>,' or <NUM>" may be formed at least partially from shape memory material, e.g., such that the markers may be biased to assume a predetermined configuration when heated to a target temperature. For example, with reference to the marker <NUM> of <FIG>, the core wire <NUM> may be formed from a shape memory material, e.g., Nitinol, such that the core wire <NUM> is in a martensitic state at or below ambient temperature, e.g., twenty degrees Celsius (<NUM>) or less, and an austenitic state at or above body temperature, e.g., thirty seven degrees Celsius (<NUM>) or more. In the martensitic state, the core wire <NUM> may be relatively soft and malleable, e.g., such that the marker <NUM> may be straightened and loaded into the delivery device <NUM> of <FIG>. The shape memory of the core wire <NUM> may be heat set or otherwise programmed into the material such that, when the core wire <NUM> is heated to the target temperature, the core wire <NUM> may become biased to the wave, helical, or other nonlinear shape. Thus, even if the marker <NUM> is bent, straightened, or otherwise deformed from its desired deployment configuration while in the martensitic state, the marker <NUM> may automatically become biased to assume the deployment configuration once introduced into a patient's body or otherwise heated to the target temperature.

Turning to <FIG>, another exemplary embodiment of a marker <NUM> is shown. Similar to the marker <NUM>, the marker <NUM> includes a core wire <NUM> carrying a plurality of beads or segments <NUM>. Each of the beads <NUM> includes a plurality of recesses 424c, e.g., for enhancing reflection of signals from a probe (not shown), such as those described elsewhere herein. The core wire <NUM> and beads <NUM> may be manufactured and assembled similar to the previous embodiments, e.g., such that the beads <NUM> are free to rotate on or are fixed to the core wire <NUM>. The recesses 424c may be formed entirely in each respective bead <NUM> or may be defined by cooperating surfaces of adjacent beads (not shown), similar to the previous embodiments. The recesses 424c may define substantially flat or curved surfaces that meet at abrupt edges defining corners that may enhance radar detection.

Optionally, as shown in <FIG>, alternative embodiments of spherical markers <NUM>, <NUM>,' <NUM>" are shown that include recesses 524c, 524c,' 524c" having different shapes and/or configurations. The recesses 524c, 524c,' 524c" may generate reflected signals that are substantially different than one another, e.g., such that a processor of a probe may be able to distinguish different markers based on the different reflected signals, as described above. In the embodiments shown in <FIG>, the markers <NUM>, <NUM>,' <NUM>" are formed from a single piece of material and do not include a core wire and multiple beads. It will be appreciated that a core wire and multiple beads may be provided, if desired, for the markers <NUM>, <NUM>,' <NUM>" and/or that the marker <NUM> of <FIG> may be formed from a single piece of material, if desired.

Turning to <FIG>, another embodiment of a delivery device <NUM> is shown that may be used for delivering a marker <NUM>, such as the marker <NUM> shown in <FIG>, but which alternatively may be any of the markers described elsewhere herein. Generally, the delivery device <NUM> includes a needle or other tubular shaft <NUM> including a proximal end 362a and a distal end 362b sized for introduction through tissue into a target tissue region, e.g., within breast <NUM>, and a lumen <NUM> extending between the proximal and distal ends 362a, 362b. The delivery device <NUM> also includes a pusher member <NUM> slidable within the shaft <NUM> for delivering the marker <NUM> from the lumen <NUM>. As shown, the distal end 362b of the shaft <NUM> may be beveled and/or otherwise sharpened such that the shaft <NUM> may be introduced directly through tissue. Alternatively, the delivery device <NUM> may be introduced through a cannula, sheath, or other tubular member (not shown) placed through tissue, e.g., as described elsewhere herein. Optionally, the distal end 362b may include a band or other feature, e.g., formed from radiopaque, echogenic, or other material, which may facilitate monitoring the distal end 362b during introduction, e.g., using x-ray or ultrasound imaging, also as described elsewhere herein.

As shown in <FIG>, the pusher member <NUM> includes a distal end <NUM> disposed within the lumen <NUM>, e.g., initially adjacent the marker <NUM> as shown in <FIG>. The pusher member <NUM> may be substantially stationary relative to a handle <NUM> of the delivery device <NUM>, while the shaft <NUM> may be retractable, e.g., for exposing the marker <NUM>, as described further below. For example, as shown in <FIG>, a proximal end 366a of the pusher member <NUM> may be fixed to a pusher holder <NUM> mounted within the handle <NUM>.

The shaft <NUM> may coupled to shaft holder <NUM>, which is slidable within the handle <NUM>. For example, the shaft holder <NUM> may be slidable axially from a first or distal position, shown in <FIG>, to a second or proximal position, shown in <FIG>. Thus, with the shaft holder <NUM> in the first position, the distal end <NUM> of the pusher member <NUM> may be offset proximally from the distal end 362b of the shaft <NUM>, thereby providing sufficient space within the shaft lumen <NUM> to receive the marker <NUM>, as shown in <FIG>. When the shaft holder <NUM> is directed to the second position, the shaft <NUM> is retracted until the distal end 362b of the shaft <NUM> is disposed adjacent the distal end <NUM> of the pusher member <NUM>, e.g., as shown in <FIG>. The distal end <NUM> of the pusher member <NUM> prevents the marker <NUM> from migrating proximally during this retraction of the shaft <NUM> such that the marker <NUM> is consequently deployed from the lumen <NUM> of the shaft <NUM>, as shown in <FIG>.

The shaft holder <NUM> and shaft <NUM> may be biased to the second position, but may be selectively retained in the first position, e.g., to allow a marker <NUM> to be loaded into and delivered using the delivery device <NUM>. For example, as shown in <FIG>, the handle <NUM> includes a spring or other mechanism received in a recess <NUM> in the housing and abutting the shaft holder <NUM>. In the first position, the spring <NUM> is compressed, as shown in <FIG>, while in the second position, the spring <NUM> is relaxed or in a lower potential energy state, as shown in <FIG>.

The handle <NUM> also includes an actuator for selectively retaining and releasing the shaft holder <NUM> and shaft <NUM> in the first position. For example, as shown in <FIG>, with the shaft holder <NUM> in the first position, the shaft holder <NUM> may be rotated within the handle <NUM> until a proximal end 374a of the shaft holder <NUM> abuts or otherwise engages a distal end 372a of the pusher holder <NUM>. Alternatively, the handle <NUM> may include one or more other features (not shown) that may selectively engage the shaft holder <NUM> in the first position. As shown in <FIG>, if the shaft holder <NUM> is rotated within the handle <NUM> to disengage the proximal end 374a from the distal end 372a of the pusher holder <NUM>, the proximal end 372a may be free to travel proximally within the handle <NUM>. Thus, once the shaft holder <NUM> is rotated, the spring <NUM> may automatically direct the shaft holder <NUM> proximally, thereby deploying the marker <NUM>. It will be appreciated that other actuators, e.g., releasable detents or locks may be provided on the handle <NUM> and/or shaft holder <NUM> that may interact to releasably secure the shaft <NUM> in its advanced position and allow the shaft <NUM> to automatically retract when the actuator is activated.

Turning to <FIG> and <FIG>, the delivery device <NUM> may be used to deliver a marker <NUM> into a breast <NUM> or other tissue structure, e.g., within a target tissue region including one or more lesions <NUM>, similar to the previous embodiments. Once the marker <NUM> is delivered, the marker <NUM> may be used to localize the target tissue region, e.g., using any of the systems and methods described elsewhere herein.

Turning to <FIG>, still another embodiment of a marker device <NUM> is shown that includes a marker <NUM> coupled to a tether or other elongate element <NUM>. The tether <NUM> may be a suture, e.g., formed from bioabsorbable or non-absorbable material, a wire, and the like, e.g., formed from flexible, rigid, or malleable material, and having sufficient length to extend out of a patient's body when the marker is introduced into a target tissue region. The marker <NUM> may be similar to the marker <NUM>'" shown in <FIG> or any of the other embodiments described elsewhere herein, and may be releasably or substantially permanently attached to a distal end <NUM> of the tether <NUM>, e.g., similar to the localization wire described elsewhere herein. Adding an elongate tether <NUM> extending from a marker <NUM> may provide an additional reference of the location of the marker <NUM> when implanted within tissue. For example, the tether <NUM> may help guide a surgeon to the exact location of the marker <NUM> during lumpectomy surgery and/or may confirm the presence of the marker <NUM> inside a removed tumor volume. The tether <NUM> may also be used to place a tag to help identify the orientation of the marker <NUM> within a target tissue region, and may be left in place or removed, as desired.

Turning to <FIG>, a delivery device <NUM> and method are shown for implanting the marker device <NUM> within a target tissue region, e.g., for implanting the marker <NUM> within a non-palpable lesion <NUM> within a breast <NUM>. Similar to previous embodiments, the delivery device <NUM> includes a shaft <NUM> including a proximal end 262a and a distal end 262b sized for introduction through tissue into a target tissue region, e.g., within breast <NUM>, and carrying the marker device <NUM>. The delivery device <NUM> may include a lumen <NUM> extending at least partially between the proximal and distal ends 662a, 662b of the shaft <NUM>, and a pusher member <NUM> slidable within the shaft <NUM> for delivering the marker <NUM> from the lumen <NUM>. As shown, the distal end 662b of the shaft <NUM> may be beveled and/or otherwise sharpened such that the shaft <NUM> may be introduced directly through tissue. Alternatively, the delivery device <NUM> may be introduced through a cannula, sheath, or other tubular member (not shown) placed through tissue, e.g., as described elsewhere herein. Optionally, the distal end 662b may include a band or other feature, e.g., formed from radiopaque, echogenic, or other material, which may facilitate monitoring the distal end 662b during introduction, also as described elsewhere herein.

As shown in <FIG>, the pusher member <NUM> includes a lumen <NUM> for slidably receiving the tether <NUM> therethrough. Thus, during manufacturing or at any time before use, the marker device <NUM> may be loaded in the delivery device <NUM> such that the marker <NUM> is disposed within the lumen <NUM> adjacent the distal end 662b and the tether <NUM> extends through the lumen <NUM> of the pusher member <NUM> and out a plunger <NUM> coupled to the pusher member <NUM>. If the marker is <NUM> is biased to a helical or other shape, the marker <NUM> may be straightened as it is loaded into the shaft <NUM>, as shown in <FIG>. The marker device <NUM> may be implanted before a lumpectomy procedure, to replace a wire localization procedure, or at the time of a biopsy. Alternatively, the marker device <NUM> may be delivered through a core needle biopsy instrument or a vacuum assisted core needle system (not shown).

For example, during a procedure, the distal end 662b may be inserted through tissue into the target tissue region, e.g., within lesion(s) <NUM>, as shown in <FIG>. Once the distal end 662b of the delivery device <NUM> has been advanced to a desired location within tissue, the shaft <NUM> may be retracted relative to a plunger <NUM> coupled to the pusher member <NUM> to deliver the marker <NUM> from the lumen <NUM>, as shown in <FIG>. As shown, the marker <NUM> may automatically and/or resiliently change shape upon deployment, e.g., returning towards the tapered helical shape shown in <FIG>. Turning to <FIG>, the delivery device <NUM> may be withdrawn from the patient's body leaving the marker <NUM> within the target tissue region, e.g., within lesion(s) <NUM>. The tether <NUM> may simply slide through the pusher member <NUM> until the end is exposed from the breast <NUM>, e.g., as shown in <FIG>.

Optionally, as shown in <FIG>, the tether <NUM> may be separated from the marker <NUM>, leaving the marker <NUM> in place within the lesion(s) <NUM>. For example, the tether <NUM> may include a weakened region (not shown) immediately adjacent the marker <NUM>, which may be broken upon application of a predetermined tension. Alternatively, the tether <NUM> may include a threaded distal end <NUM> or other connectors that may be released from the marker <NUM>, e.g., by rotating the tether <NUM> to unthread the distal end <NUM> from the marker <NUM>. Alternatively, the tether <NUM> may remain attached to the marker <NUM> during a subsequent lumpectomy or other procedure.

Turning to <FIG>, another exemplary embodiment of a marker device <NUM>' is shown that is generally similar to the marker device <NUM>, i.e., including a tether <NUM> and a marker <NUM>. ' However, the marker <NUM>' may be similar to the marker <NUM>"" shown in <FIG>. <FIG> show an exemplary embodiment of a delivery device <NUM>' and method for implanting the marker device <NUM>,' which are generally similar to that shown in <FIG>.

Although the systems and methods described above relate to lesions within breasts, one or more markers or targets may be implanted or otherwise introduced into other regions of a patient's body for subsequent localization using a probe, such as probe <NUM> described above. For example, one or more targets may be placed within or adjacent a bile duct, femoral artery or vein, fallopian tube, or other body lumen for subsequent localization. The target(s) may be carried by a catheter, wire, or other delivery device within the lumen of the body lumen from a remote access site and secured therein, e.g., by immobilizing the catheter or wire, or by anchoring the marker(s) to, within, or through the wall of the body lumen or otherwise within the body lumen.

For example, <FIG> shows a gastrointestinal tract <NUM> of a patient upon whom one or more diagnostic and/or therapeutic procedures are to be performed. As shown, a catheter <NUM> carrying a marker <NUM> may be introduced into the patient's GI tract <NUM>, e.g., via the mouth or rectum. As can be seen in <FIG>, the catheter <NUM> may include a marker <NUM>, e.g., similar to the other markers described elsewhere herein. For example, the marker <NUM> may include features similar to one or more of the beads <NUM> shown in <FIG> and described above. The catheter <NUM> and marker <NUM> may be advanced to a desired location within the GI tract <NUM>, e.g., using fluoroscopy, ultrasound, or other external imaging.

A probe, such as any of those described elsewhere herein, may then be used to locate the marker <NUM>, and thereby locate the location in the GI tract <NUM>. It will be appreciated that other body lumens may be localized in a similar manner, e.g., to facilitate access to the body lumen, e.g., in a minimally invasive manner from outside the patient's body. For example, as shown in <FIG>, the marker <NUM> may be used to locate a particular location in the GI tract <NUM>, e.g., to facilitate puncturing the wall and enter the body lumen, to clip, cut, ligate, or otherwise close the body lumen, and the like. <FIG> is a cross-sectional view of an insufflated abdomen <NUM>, e.g., using conventional laparoscopic procedures. A probe <NUM>, which may be similar to any of the probes described elsewhere herein, may be inserted through an access cannula <NUM> to scan and/or detect the location of the marker <NUM> on the catheter <NUM>. A laparoscope <NUM> may then be used to visualize the position of the probe <NUM> relative to the marker <NUM>. Once the marker <NUM> has been located, an access sheath <NUM> may be used to gain access to the GI tract <NUM> at the desired location, e.g., to perform one or more diagnostic and/or therapeutic procedures. The marker <NUM> and catheter <NUM> may be removed once access is achieved or after the procedure(s) is complete, as desired.

In an exemplary embodiment, a marker may be introduced into a fallopian tube using a catheter, and then a needle or other device may be introduced in a minimally invasive manner, e.g., punctured through the patient's skin and tissue above the marker to access the fallopian tube, for example, to ligate, cauterize, or otherwise sever or close the fallopian tube. Alternatively, if a marker is placed within a bile duct, endoscopic access may be used under guidance of the probe <NUM> to access the bile duct, e.g., to perform a procedure within a patient's intestine. In a further alternative, markers may be placed in branches communicating with a length of femoral artery, vein, or other vessel intended for harvest, and then the probe <NUM> may be used to localize each of the branches external to the vessel, e.g., such that each branch may be cut, ligated, cauterized, and/or otherwise separated, to allow the length of vessel to be separated from the adjacent vessels and harvested.

In a further alternative, one or more markers may be implanted within a target tissue structure for localized therapy using the systems described herein. For example, the marker(s) may carry one or more drugs, radioactive material, or other therapeutic substances that may be released over an extended time within or around the target tissue region in which they are implanted. After sufficient time, e.g., after the therapeutic substance(s) have been substantially completely depleted or otherwise sufficiently delivered, the probe <NUM> may be used to localize the marker(s) to facilitate recovering and/or removing the marker(s), e.g., in a minimally invasive manner.

Claim 1:
A marker (<NUM>) for localization of a target tissue region within a patient's body, comprising:
an elongate core member (<NUM>);
characterized in that the marker further comprises a plurality of beads (<NUM>) coupled to the core member, the beads comprising a plurality of surfaces and edges to enhance reflection of electromagnetic signals to facilitate identification of the marker.