Patent Description:
In the context of Eustachian tube dilation, a dilation catheter or other dilation instrument may be inserted into the Eustachian tube and then be inflated or otherwise expanded to thereby dilate the Eustachian tube. The dilated Eustachian tube may provide improved ventilation from the nasopharynx to the middle ear and further provide improved drainage from the middle ear to the nasopharynx. Methods and devices for dilating the Eustachian tube are disclosed in <CIT>; and <CIT>. An example of such a system is the Aera® Eustachian Tube Balloon Dilation System by Acclarent, Inc. of Irvine, California.

Image-guided surgery (IGS) is a technique where a computer is used to obtain a real-time correlation of the location of an instrument that has been inserted into a patient's body to a set of preoperatively obtained images (e.g., a CT or MRI scan, <NUM>-D map, etc.), such that the computer system may superimpose the current location of the instrument on the preoperatively obtained images. An example of an electromagnetic IGS navigation systems that may be used in IGS procedures is the CARTO® <NUM> System by Biosense-Webster, Inc. , of Irvine, California. In some IGS procedures, a digital tomographic scan (e.g., CT or MRI, <NUM>-D map, etc.) of the operative field is obtained prior to surgery. A specially programmed computer is then used to convert the digital tomographic scan data into a digital map. During surgery, special instruments having sensors (e.g., electromagnetic coils that emit electromagnetic fields and/or are responsive to externally generated electromagnetic fields) are used to perform the procedure while the sensors send data to the computer indicating the current position of each surgical instrument. The computer correlates the data it receives from the sensors with the digital map that was created from the preoperative tomographic scan. The tomographic scan images are displayed on a video monitor along with an indicator (e.g., crosshairs or an illuminated dot, etc.) showing the real-time position of each surgical instrument relative to the anatomical structures shown in the scan images. The surgeon is thus able to know the precise position of each sensor-equipped instrument by viewing the video monitor even if the surgeon is unable to directly visualize the instrument itself at its current location within the body.

<CIT> describes an apparatus including a proximal coil, a distal potion, a navigation sensor, and a communication wire. The proximal coil is formed by a wire wrapped in a helical configuration. The proximal coil is flexible. The distal portion is positioned at a distal end of the proximal coil. The distal portion is non-extensible. The distal portion may be formed by a rigid tube. The distal portion may alternatively be formed by a soldered region of the proximal coil. The navigation sensor is located within the distal portion. The navigation sensor is configured to generate signals in response to movement within an electromagnetic field. The communication wire is in electrical communication with the navigation sensor such that the communication wire is configured to communicate signals from the navigation sensor.

While several systems and methods have been made and used in surgical procedures, it is believed that no one prior to the inventors has made or used the invention described in the appended claims.

While the specification concludes with claims which particularly point out and distinctly claim the invention, it is believed the present invention will be better understood from the following description of certain examples taken in conjunction with the accompanying drawings, in which like reference numerals identify the same elements and in which:.

The invention is defined by the appended independent claim <NUM>.

It will be appreciated that the terms "proximal" and "distal" are used herein with reference to a clinician gripping a handpiece assembly. Thus, an end effector is distal with respect to the more proximal handpiece assembly. It will be further appreciated that, for convenience and clarity, spatial terms such as "top" and "bottom" also are used herein with respect to the clinician gripping the handpiece assembly. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and absolute.

It is further understood that any one or more of the teachings, expressions, versions, examples, etc. described herein may be combined with any one or more of the other teachings, expressions, versions, examples, etc. that are described herein. The following-described teachings, expressions, versions, examples, etc. should therefore not be viewed in isolation relative to each other. Various suitable ways in which the teachings herein may be combined will be readily apparent to those skilled in the art in view of the teachings herein.

When performing a medical procedure within a head (H) of a patient (P), it may be desirable to have information regarding the position of an instrument within the head (H) of the patient (P), particularly when the instrument is in a location where it is difficult or impossible to obtain an endoscopic view of a working element of the instrument within the head (H) of the patient (P). <FIG> shows an exemplary IGS navigation system (<NUM>) enabling an ENT procedure to be performed using image guidance. In addition to or in lieu of having the components and operability described herein IGS navigation system (<NUM>) may be constructed and operable in accordance with at least some of the teachings of <CIT>; and <CIT>.

IGS navigation system (<NUM>) of the present example comprises a field generator assembly (<NUM>), which comprises set of magnetic field generators (<NUM>) that are integrated into a horseshoe-shaped frame (<NUM>). Field generators (<NUM>) are operable to generate alternating magnetic fields of different frequencies around the head (H) of the patient (P). A navigation guidewire (<NUM>) is inserted into the head (H) of the patient (P) in this example. Navigation guidewire (<NUM>) may be a standalone device or may be positioned on an end effector or other location of a medical instrument such as a surgical cutting instrument or dilation instrument. In the present example, frame (<NUM>) is mounted to a chair (<NUM>), with the patient (P) being seated in the chair (<NUM>) such that frame (<NUM>) is located adjacent to the head (H) of the patient (P). By way of example only, chair (<NUM>) and/or field generator assembly (<NUM>) may be configured and operable in accordance with at least some of the teachings of <CIT>, published as <CIT>.

IGS navigation system (<NUM>) of the present example further comprises a processor (<NUM>), which controls field generators (<NUM>) and other elements of IGS navigation system (<NUM>). For instance, processor (<NUM>) is operable to drive field generators (<NUM>) to generate alternating electromagnetic fields; and process signals from navigation guidewire (<NUM>) to determine the location of a sensor in navigation guidewire (<NUM>) within the head (H) of the patient (P). Processor (<NUM>) comprises a processing unit communicating with one or more memories. Processor (<NUM>) of the present example is mounted in a console (<NUM>), which comprises operating controls (<NUM>) that include a keypad and/or a pointing device such as a mouse or trackball. A physician uses operating controls (<NUM>) to interact with processor (<NUM>) while performing the surgical procedure.

Navigation guidewire (<NUM>) includes a sensor (not shown) that is responsive to positioning within the alternating magnetic fields generated by field generators (<NUM>). A coupling unit (<NUM>) is secured to the proximal end of navigation guidewire (<NUM>) and is configured to provide communication of data and other signals between console (<NUM>) and navigation guidewire (<NUM>). Coupling unit (<NUM>) may provide wired or wireless communication of data and other signals.

In the present example, the sensor of navigation guidewire (<NUM>) comprises at least one coil at the distal end of navigation guidewire (<NUM>). When such a coil is positioned within an alternating electromagnetic field generated by field generators (<NUM>), the alternating magnetic field may generate electrical current in the coil, and this electrical current may be communicated along the electrical conduit(s) in navigation guidewire (<NUM>) and further to processor (<NUM>) via coupling unit (<NUM>). This phenomenon may enable IGS navigation system (<NUM>) to determine the location of the distal end of navigation guidewire (<NUM>) or other medical instrument (e.g., dilation instrument, surgical cutting instrument, etc.) within a three-dimensional space (i.e., within the head (H) of the patient (P), etc.). To accomplish this, processor (<NUM>) executes an algorithm to calculate location coordinates of the distal end of navigation guidewire (<NUM>) from the position related signals of the coil(s) in navigation guidewire (<NUM>). While the position sensor is located in guidewire (<NUM>) in this example, such a position sensor may be integrated into various other kinds of instruments, including those described in greater detail below.

Processor (<NUM>) uses software stored in a memory of processor (<NUM>) to calibrate and operate IGS navigation system (<NUM>). Such operation includes driving field generators (<NUM>), processing data from navigation guidewire (<NUM>), processing data from operating controls (<NUM>), and driving display screen (<NUM>). In some implementations, operation may also include monitoring and enforcement of one or more safety features or functions of IGS navigation system (<NUM>). Processor (<NUM>) is further operable to provide video in real time via display screen (<NUM>), showing the position of the distal end of navigation guidewire (<NUM>) in relation to a video camera image of the patient's head (H), a CT scan image of the patient's head (H), and/or a computer generated three-dimensional model of the anatomy within and adjacent to the patient's nasal cavity. Display screen (<NUM>) may display such images simultaneously and/or superimposed on each other during the surgical procedure. Such displayed images may also include graphical representations of instruments that are inserted in the patient's head (H), such as navigation guidewire (<NUM>), such that the operator may view the virtual rendering of the instrument at its actual location in real time. By way of example only, display screen (<NUM>) may provide images in accordance with at least some of the teachings of <CIT>. In the event that the operator is also using an endoscope, the endoscopic image may also be provided on display screen (<NUM>).

The images provided through display screen (<NUM>) may help guide the operator in maneuvering and otherwise manipulating instruments within the patient's head (H) when such instruments incorporate navigation guidewire (<NUM>). It should also be understood that other components of a surgical instrument and other kinds of surgical instruments, as described below, may incorporate a sensor like the sensor of navigation guidewire (<NUM>).

As noted above, it may be desirable to use an instrument to dilate one or more anatomical passageways within a head of a patient, including but not limited to a Eustachian tube, an ostium of a paranasal sinus, or other passageways associated with drainage of a paranasal sinus. Each anatomical passageway may require an entry angle that is uniquely associated with that particular anatomical passageway. For instance, entry of a dilation catheter into a maxillary sinus ostium may require an angle of entry that differs from the angle of entry required for entry of a dilation catheter into a frontal recess of a frontal sinus. It may therefore be desirable to provide an instrument guide feature that is malleable, thereby enabling the operator to adjust the dilation instrument based on the needs at hand. Malleability of an instrument guide feature may also allow the operator to dilate different passageways at different entry angles within the same medical procedure, such that the operator may bend the guide feature between dilations to achieve different exit angles. Examples of dilation instruments with malleable guide features are disclosed in <CIT>; <CIT>; and <CIT>, published as <CIT>.

In addition to providing malleability in a guide feature of a dilation instrument, it may also be desirable to incorporate one or more position sensors into the dilation instrument, to provide compatibility with IGS navigation system (<NUM>). As noted above, this may be accomplished by incorporating a position sensor in a guidewire (<NUM>) that is used with the dilation instrument. In some instances, it may be desirable to use a dilation instrument without using a guidewire (<NUM>). In some such instances, a position sensor may be integrated into some other component of the dilation instrument, such as a dilation catheter. Examples of dilation catheters that incorporate a position sensor are described in <CIT>, published as <CIT>; and <CIT>, published as <CIT>.

It may further be desirable to provide a dilation instrument that includes both a malleable guide feature and a position sensor that is integral with a dilation catheter, without requiring an additional guidewire. The malleability and position sensing may provide the benefits noted above; while omission of a guidewire may reduce the cost and complexity of the instrument. An example of such an instrument is described in greater detail below.

<FIG> show an exemplary dilation instrument (<NUM>) that includes a handle assembly (<NUM>), a guide tube (<NUM>) extending distally from handle assembly (<NUM>), and a dilation catheter (<NUM>) that is slidably disposed in guide tube (<NUM>). Dilation catheter (<NUM>) is coupled with a slider (<NUM>) of handle assembly (<NUM>). Slider (<NUM>) is operable to translate longitudinally along a slot (<NUM>) of handle assembly (<NUM>) to thereby drive dilation catheter (<NUM>) between a proximal position (<FIG>) and a distal position (<FIG>). Various suitable ways in which slider (<NUM>) and dilation catheter (<NUM>) may be coupled will be apparent to those skilled in the art in view of the teachings herein.

Handle assembly (<NUM>) of the present example further includes an inflation port (<NUM>). Inflation port (<NUM>) may comprise a conventional luer fitting or any other suitable kind of structure. Inflation port (<NUM>) is in fluid communication with a dilator (<NUM>) of dilation catheter (<NUM>). Dilator (<NUM>) will be described in greater detail below. Various suitable ways in which inflation port (<NUM>) may be coupled with dilator (<NUM>) will be apparent to those skilled in the art in view of the teachings herein. Inflation port (<NUM>) is further configured to couple with a conduit (<NUM>), which is further coupled with a fluid source (<NUM>). Fluid source (<NUM>) is configured to provide inflation fluid (e.g., saline, etc.) to dilator (<NUM>) via conduit (<NUM>) and inflation port (<NUM>). By way of example only, fluid source (<NUM>) may be configured and operable in accordance with at least some of the teachings of <CIT>.

Handle assembly (<NUM>) of the present example further includes a cable port (<NUM>), which is coupled with a cable (<NUM>). Cable port (<NUM>) is further in communication with a position sensor (<NUM>) of dilation catheter (<NUM>). Position sensor (<NUM>) will be described in greater detail below. Various suitable ways in which cable port (<NUM>) may be coupled with position sensor (<NUM>) will be apparent to those skilled in the art in view of the teachings herein. Cable (<NUM>) leads to a plug (<NUM>), which is configured to couple with processor (<NUM>) of IGS navigation system (<NUM>). Cable port (<NUM>), cable (<NUM>), and plug (<NUM>) thus provide a pathway for communication of position-indicative signals from position sensor (<NUM>) to processor (<NUM>), thereby enabling processor (<NUM>) to determine the position of sensor (<NUM>) in three-dimensional space. By way of example only, plug (<NUM>) may couple with processor (<NUM>) via a conventional USB coupling or in any other suitable fashion. As another merely illustrative example, instrument (<NUM>) may provide wireless communication of position-indicative signals from position sensor (<NUM>) to processor (<NUM>).

As best seen in <FIG>, dilation catheter (<NUM>) of the present example includes a shaft (<NUM>) with a distal end (<NUM>), a dilator (<NUM>) that is proximal to distal end (<NUM>), and a position sensor (<NUM>) that is longitudinally interposed between dilator (<NUM>) and distal end (<NUM>). Dilator (<NUM>) of the present example comprises a balloon that is configured to transition between the non-expanded state (<FIG>) and the expanded state (<FIG>) based on communication of fluid from and to fluid source (<NUM>). In the non-expanded state, dilator (<NUM>) is configured to fit within anatomical passageways such as a Eustachian tube, an ostium of a paranasal sinus, and other passageways associated with drainage of a paranasal sinus. In the expanded state, dilator (<NUM>) is configured to dilate such a passageway.

Position sensor (<NUM>) of the present example comprises a wire coil that is wrapped about the central longitudinal axis of catheter shaft (<NUM>). When position sensor (<NUM>) is positioned within an alternating electromagnetic field generated by field generators (<NUM>), the alternating magnetic field may generate electrical current in position sensor (<NUM>), and this electrical current may be communicated along an electrical conduit dilation catheter (<NUM>) and further to processor (<NUM>) via cable port (<NUM>), cable (<NUM>), and plug (<NUM>). This phenomenon may enable IGS navigation system (<NUM>) to determine the location of distal end (<NUM>) of dilation catheter (<NUM>) within a three-dimensional space (i.e., within the head (H) of the patient (P), etc.). To accomplish this, processor (<NUM>) executes an algorithm to calculate location coordinates of the distal end (<NUM>) of dilation catheter (<NUM>) from the position related signals of the position sensor (<NUM>) in dilation catheter (<NUM>).

In the present example, when dilation catheter (<NUM>) is in the retracted position as shown in <FIG>, distal end (<NUM>) of dilation catheter (<NUM>) is at substantially the same longitudinal position as distal end (<NUM>) of guide tube (<NUM>). Thus, the signals from position sensor (<NUM>) will effectively convey the position of distal end (<NUM>) of guide tube (<NUM>) when dilation catheter (<NUM>) is in the retracted position as shown in <FIG>, even if guide tube (<NUM>) is in a bent state as described in greater detail below. The operator may thus rely on feedback from IGS navigation system (<NUM>) when navigating distal end (<NUM>) of guide tube (<NUM>) to the appropriate position in the head (H) of the patient (P) while dilation catheter (<NUM>) is in the retracted position.

Once distal end (<NUM>) of guide tube (<NUM>) has reached the appropriate position in the head (H) of the patient (P), and the operator has observed this positioning via IGS navigation system (<NUM>), the operator may advance slider (<NUM>) along slot (<NUM>) to advance dilation catheter (<NUM>) relative to guide tube (<NUM>) to the advanced position shown in <FIG>. Since position sensor (<NUM>) is integral with dilation catheter (<NUM>), position sensor (<NUM>) will also be advanced, thereby providing a signal indicating the location of distal end (<NUM>) in the head (H) of the patient (P). The operator may again consult IGS navigation system (<NUM>) to observe whether distal end (<NUM>) of dilation catheter (<NUM>) is at an appropriate position in the head (H) of the patient (P), which may further indicate that dilator (<NUM>) is properly located in the targeted anatomical passageway. Once distal end (<NUM>) of dilation catheter (<NUM>) has reached the appropriate position in the head (H) of the patient (P), and the operator has observed this positioning via IGS navigation system (<NUM>), the operator may actuate fluid source (<NUM>) to inflate dilator (<NUM>) as shown in <FIG> and thereby dilate the targeted anatomical passageway.

Guide tube (<NUM>) of the present example is formed of a malleable material such as metal. The operator may thus bend guide tube (<NUM>) from the straight configuration shown in <FIG> to a bent configuration on an ad hoc basis in order to facilitate access to the targeted anatomical passageway. By way of example only, guide tube (<NUM>) may be formed of a stainless steel hypotube. <FIG> shows an exemplary bent form of guide tube (<NUM>), where a bend (<NUM>) has been provided just proximal to distal end (<NUM>). Various suitable bend angles associated with various potentially targeted anatomical passageways will be apparent to those skilled in the art in view of the teachings herein. Guide tube (<NUM>) is configured to maintain bend (<NUM>) during normal use of instrument (<NUM>), including when dilation catheter (<NUM>) translates relative to guide tube (<NUM>).

In some scenarios, a separate bending instrument may be used to precisely and reliably form bend (<NUM>). An example of such an instrument is described in <CIT>. As noted above, since position sensor (<NUM>) is effectively positioned at distal end (<NUM>) of guide tube (<NUM>) when dilation catheter (<NUM>) is in the retracted position, signals from position sensor (<NUM>) will effectively indicate the position of distal end (<NUM>) in three-dimensional space when dilation catheter (<NUM>) is in the retracted position.

In some versions, guide tube (<NUM>) defines an inner diameter that is substantially larger than the outer diameter of dilation catheter (<NUM>), such that a substantial gap is defined between the outer diameter of dilation catheter (<NUM>) and the inner diameter of guide tube (<NUM>). This may allow instrument (<NUM>) to provide suction, irrigation, or other functionality through the gap. Moreover, some such versions may have dilation catheter (<NUM>) positioned such that the central longitudinal axis of dilation catheter (<NUM>) is laterally offset from the central longitudinal axis of guide tube (<NUM>). In other words, by positioning dilation catheter (<NUM>) non-coaxially relative to guide tube (<NUM>), the gap defined between the outer diameter of dilation catheter (<NUM>) and the inner diameter of guide tube (<NUM>) may be more easily used to position other features. <FIG> shows an example of such an arrangement, where dilation catheter (<NUM>) is non-coaxially positioned relative to guide tube (<NUM>), and with a substantial gap (<NUM>) defined between the outer diameter of dilation catheter (<NUM>) and the inner diameter of guide tube (<NUM>) may be more easily used to position other features. By way of example only, an irrigation device, suction device, ablation device, or other device may be positioned in gap (<NUM>).

It should be understood that any of the examples described herein may include various other features in addition to or in lieu of those described above.

Various suitable ways in which the teachings herein may be combined will be readily apparent to those skilled in the art in view of the teachings herein.

Versions of the devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In particular, versions of the device may be disassembled, and any number of the particular pieces or parts of the device may be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, versions of the device may be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure.

By way of example only, versions described herein may be processed before surgery. First, a new or used instrument may be obtained and if necessary cleaned. The instrument may then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and instrument may then be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation may kill bacteria on the instrument and in the container. The sterilized instrument may then be stored in the sterile container. The sealed container may keep the instrument sterile until it is opened in a surgical facility.

Claim 1:
An apparatus, comprising:
(a) a dilation instrument (<NUM>), the dilation instrument comprising:
(i) a guide tube (<NUM>) having a malleable distal portion, and
(ii) a dilation catheter (<NUM>) slidably positioned in the guide tube, wherein the dilation catheter is configured to translate relative to the guide tube, wherein the dilation catheter includes:
(A) a distal end (<NUM>),
(B) a dilator (<NUM>), and
(C) a position sensor (<NUM>);
(b) a fluid source (<NUM>) in fluid communication with the dilator; and
(c) an image guided surgery system (<NUM>) in communication with the position sensor, wherein the image guided surgery system is configured to determine a position of the position sensor in three-dimensional space based on signals generated by the position sensor,
wherein the guide tube defines an inner diameter, wherein the dilation catheter defines an outer diameter, wherein the guide tube and the dilation catheter cooperate to define a gap (<NUM>) between the inner diameter of the guide tube and the outer diameter of the dilation catheter.