WO2016112066A1 - Dispositif interventionnel orientable détectable - Google Patents

Dispositif interventionnel orientable détectable Download PDF

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Publication number
WO2016112066A1
WO2016112066A1 PCT/US2016/012271 US2016012271W WO2016112066A1 WO 2016112066 A1 WO2016112066 A1 WO 2016112066A1 US 2016012271 W US2016012271 W US 2016012271W WO 2016112066 A1 WO2016112066 A1 WO 2016112066A1
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WO
WIPO (PCT)
Prior art keywords
interventional device
extruded portion
dilator
extruded
lumens
Prior art date
Application number
PCT/US2016/012271
Other languages
English (en)
Inventor
Scott Kimmel
Steven R. Wedan
Thomas W. Lloyd
Original Assignee
Imricor Medical Systems, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Imricor Medical Systems, Inc. filed Critical Imricor Medical Systems, Inc.
Publication of WO2016112066A1 publication Critical patent/WO2016112066A1/fr

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/06—Devices, other than using radiation, for detecting or locating foreign bodies ; determining position of probes within or on the body of the patient
    • A61B5/065—Determining position of the probe employing exclusively positioning means located on or in the probe, e.g. using position sensors arranged on the probe
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
    • A61B2562/16—Details of sensor housings or probes; Details of structural supports for sensors
    • A61B2562/166—Details of sensor housings or probes; Details of structural supports for sensors the sensor is mounted on a specially adapted printed circuit board

Definitions

  • This invention relates to a deflectable trackable interventional device, such as a dilator, having a deflectable sheath shaft, for use in interventional vascular procedures. More particularly, the present invention is related to a deflectable sheath shaft that incorporates a unique multi-lumen design for housing the transmission line to protect the transmission lines from tension that may result from deflection and interference with other components.
  • MRI has achieved prominence as a diagnostic imaging modality, and increasingly as an interventional imaging modality.
  • the primary benefits of MRI over other imaging modalities, such as X-ray, include superior soft tissue imaging and avoiding patient exposure to ionizing radiation produced by X-rays.
  • MRI's superior soft tissue imaging capabilities offer significant clinical benefits with respect to diagnostic imaging, and similarly, interventional procedures, which traditionally use X-ray imaging for guidance, stand to benefit greatly from MRI's enhanced soft tissue visualizations.
  • the significant patient exposure to ionizing radiation associated with traditional X-ray guided interventional procedures is eliminated with MRI guidance.
  • a variety of MRI techniques are being developed as alternatives to X- ray imaging for guiding interventional procedures.
  • a medical device As a medical device is advanced through the patient's body during an interventional procedure, its progress may be tracked so that the device can be delivered properly to a target site. Once delivered to the target site, the device and patient tissue may be monitored to improve therapy delivery.
  • tracking the position of medical devices is useful in interventional procedures.
  • Exemplary interventional procedures that may benefit from this technology include cardiac electrophysiology ablation procedures such as atrial fibrillation ablation, ventricular tachycardia ablation, atrial flutter ablation, Wolfe Parkinson White Syndrome ablation, AV node ablation, SVT ablations, and the like.
  • Tracking the position of medical devices using MRI is also useful in oncological procedures such as breast, liver, and prostate tumor ablations and urological procedures such as uterine fibroid and enlarged prostate ablations as well as structural heart procedures such as valve replacement and procedures to correct ventricular spatial defects.
  • oncological procedures such as breast, liver, and prostate tumor ablations and urological procedures such as uterine fibroid and enlarged prostate ablations
  • structural heart procedures such as valve replacement and procedures to correct ventricular spatial defects.
  • interventional procedures involving the injection of stem cells, tissue, or materials for radiation therapy may benefit from this technology.
  • MRI uses three fields to image patient anatomy: a large static magnetic field, a time-varying magnetic gradient field, and a radiofrequency (RF) electromagnetic field.
  • the static magnetic field and time-varying magnetic gradient field work in concert to establish both proton alignment with the static magnetic field and also spatially dependent proton spin frequencies (resonant frequencies) within the patient.
  • the RF field applied at the resonance frequencies, disturbs the initial alignment, such that when the protons relax back to their initial alignment, the RF emitted from the relaxation event may be detected and processed to create an image.
  • Each of the three fields associated with MRI presents safety risks to patients when a medical device is in close proximity to or in contact either externally or internally with patient tissue.
  • One important safety risk is the heating that may result from an interaction between the RF field of the MRI scanner and the medical device (RF-induced heating), especially medical devices that have elongated conductive structures, such as braiding and pull-wires in catheters and sheaths.
  • the RF-induced heating safety risk associated with elongated metallic structures in the MRI environment results from a coupling between the RF field and the metallic structure.
  • several heating related conditions exist.
  • RF currents induced in the metallic structure may be delivered into the tissue, resulting in a high current density in the tissue and associated Joule or Ohmic tissue heating.
  • RF induced currents in the metallic structure may result in increased local specific absorption of RF energy in nearby tissue, thus increasing the tissue's temperature.
  • the foregoing phenomenon is referred to as dielectric heating. Dielectric heating may occur even if the metallic structure does not electrically contact tissue, such as with metallic braiding used in a deflectable sheath.
  • RF induced currents in the metallic structure may cause Ohmic heating in the structure itself and the resultant heat may transfer to the patient. In such cases, it is important to attempt to both reduce the RF induced current present in the metallic structure and/or eliminate it all together by not utilizing metal braid and/or long metallic pull-wires.
  • the static field of the MRI will cause magnetically induced displacement torque on any device containing ferromagnetic materials and has the potential to cause unwanted device movement. It is important to construct the sheath and control handle from non-magnetic materials to eliminate the risk of unwanted device movement.
  • the transmission lines that are utilized in conjunction with the deflectable sheaths are quite fragile for a variety of reasons including size, filters, connection points. When placed in the lumen of conventional sheaths it cause tension on the transmission lines and interference with nearby components frequently resulting in failure of the line.
  • a steerable sheath with a dedicated lumen for the transmission lines that includes active tracking capabilities for better visualization and tracking of the catheter tip.
  • an antenna design that facilitates active tracking that is simple to construct, has consistent electrical characteristics, reduces variation in antenna performance and can be integrated into a sheath or catheter is especially needed.
  • the interventional device is a tractable dilator.
  • the interventional device includes a deflectable sheath shaft having a first extruded portion and a second extruded portion, said first extruded portion having a cross-sectional area larger than a cross-sectional area of said second extruded portion, said first and second extruded portions formed in a co-axial relationship, wherein said first and second extruded portions form a plurality of isolated lumens for housing components of the trackable dilator.
  • the main dilator shaft is composed of a single lumen extrusion that has a cross-sectional area that is larger than a cross-sectional area of a second extruded portion.
  • the larger extruded portion is constructed of HDPE or a similar material that is co-axially assembled with a second extruded portion that has a smaller cross-sectional area that the first extruded portion and is constructed of polyimide or a similar material.
  • the larger extrusion has an irregular inner lumen shape and the smaller extrusion is round.
  • the first and second extruded portions are assembled in a coaxial relationship whereby two or more distinct and separate lumens are created.
  • the two or more lumens function as channels for transmission lines and the second extruded portion or inner lumen functions as the transseptal needle lumen.
  • a scratch resistant material such as polyimide is used for the inner lumen to eliminate particulate generation that can arise when the tip of a transseptal needle skives the inner surface of the dilator/lumen.
  • a tip support is slid over the smaller extruded portion, in order to assemble the distal tip of the dilator.
  • a flex printed circuit board which includes one or more tracking coils, is wrapped and bonded around the tip support and soldered to transmission lines used to transmit the tracking signal to an external electronic control.
  • the flexible circuit including the tracking coils consists of a printed circuit board (PCB) that forms a coil when conformed into a cylindrical shape.
  • PCB printed circuit board
  • the PCB contains one or more conductive traces spanning from one side of the PCB to the other.
  • a fixture is used to turn the PCB around a core and formed into a consistent cylindrical shape so that the edges of the board are adjacent or overlap each other.
  • the ends of the PCB are adjoined electrically by connecting one end of the trace to the other end of its corresponding trace, thus creating a turn.
  • the coil's proximal and distal traces are connected to soldering pads for a matching network circuit.
  • a matching network circuit is placed on the board to match the coil's output impedance to that of the transmission line to maximize the power transfer and/or minimize signal loss.
  • the inductance of the coil is dependent on the physical dimensions, number of turns, permeability of the core, and the material used in the construction of the board.
  • the PCB may contain one or more coils per board.
  • the flexible PCB circuit is intended to decrease the difficulty of creating a miniature coil, producing a more consistent and repeatable coil compared to a hand- wound coil.
  • a dilator tip made out of PEEK, or a polymer such as HDPE or a similar material, is slid over the smaller extrusion and bonded to the tip support and smaller extrusion.
  • a thinner extrusion made of HDPE or a similar material is slid over the proximal section of the dilator tip, the tip support and the flex circuit and reflowed such that a continuous outer surface is formed connecting the dilator tip to the larger extrusion.
  • more than two transmission line lumens may be created by modifying the profile of the larger outer extruded portion extrusion. This allows for additional tracking coils to be added to the dilator distal tip.
  • FIG. 1 depicts the shaft of an interventional device, such as a dilator, having a base irregular extrusion profile.
  • FIG. 2 shows the first larger base extrusion with a second smaller extrusion located within the larger extrusion.
  • FIG. 3 is an isometric view showing the creation of the transmission lumens by coaxially assembling the smaller extrusion and the larger extrusion.
  • FIG. 4 is an isometric view showing the creation of the transmission lumens by coaxially assembling the smaller extrusion and the larger extrusion with the transmission lines present.
  • FIG. 5 is an isometric view showing a tip support placed axially over smaller inner lumen and also shows a flexible printed circuit board containing two tracking coils placed on the tip support and connected to the transmission lines.
  • FIG. 6 is an isometric view of the dilator with dilator tip in place.
  • FIG. 7 is an isometric view of the dilator with the thin extrusion placed over the printed circuit board.
  • FIG. 8 shows a three transmission line lumen design.
  • FIG. 9 shows a four transmission line lumen design.
  • FIG. 10 depicts a flexible printed circuit board forming two solenoid antennas.
  • FIG. 11 is an alternative view of a flexible printed circuit board forming two solenoid antennas. Pads and capacitors also shown. Traces from the antennas to the pads are not shown.
  • FIG. 12 is an alternative view of a flexible printed circuit board forming two solenoid antennas. Pads and capacitors also shown. Traces from the antennas to the pads are not shown.
  • FIG. 13 shows the flexible printed circuit board shown on the tip support.
  • FIG. 14 is an alternative view of the flexible printed circuit board shown on the tip support.
  • FIG. 15 shows the outer and inner layers of a flexible printed circuit board (PCB) with two solenoid antennas prior to being formed into a cylinder.
  • PCB printed circuit board
  • Various aspects of the trackable deflectable sheath 10 in accordance with the invention include the incorporation of one or more receive antennas for active MR tracking onto an MRI compatible deflectable sheath.
  • the one or more receive antennas can be incorporated into the sheath itself or integrated into a dilator used in conjunction with the sheath.
  • Many aspects of this invention involve integrating the receive antennas into a dilator.
  • the invention includes the use of flex printed circuit boards to form one or more solenoid antennas.
  • Use of flexible PCB to form the antennas (or tracking coils) is not limited to a trackable sheath and/or dilator. Use of such a design has the potential to improve the manufacturability, repeatability, and quality of antennas used in any actively tracked device for MR guided interventional procedures.
  • Integrating MR receive coils (also referred to as antennas or tracking coils) into a sheath and/or dilator allows the sheath to be visualized during MR guided interventional procedures.
  • the integrated receive coils receive electrical signals from MR visible material near the coil and transmit the signals to an external control unit that processes the data to determine the coordinates of the coil within the imaging volume of an MRI. The coordinates are then used to depict the sheath in images obtained during MR imaging.
  • a common method for manufacturing a solenoid antenna involves wrapping wire around the support for the antenna. Because of the small size of the antenna used in this application, physical wrapping of the wire is difficult to automate, which leads to significant process variation from antenna to antenna. Disadvantageously, even small variations in the physical dimensions of the antenna significantly change the electrical characteristics of the antenna, which in turn impact the performance of the antenna and change the capacitance required to match the antenna to its transmission line. Individually wrapping and matching each antenna is a time consuming process that makes large scale manufacturing impractical.
  • Using a flexible printed circuit board to construct a solenoid antenna resolves many of the manufacturing challenges associated with integrating antennas into interventional devices.
  • a flexible printed circuit board allows precise placement of the individual traces that form the solenoid, which in conjunction with a consistently sized support or base, result in a highly repeatable manufacturing process and consistent electrical characteristics. As a result, the components used to match and tune the antenna do not vary between antennas and can be populated automatically. This allows for automation of the antenna manufacturing resulting in more efficient and better controlled manufacturing of the interventional device with improved overall yield.
  • the flexible printed circuit board 50 contains two individual circuits each comprising an antenna 52, 54 and matching network.
  • Each antenna is formed by a series of traces 72, 74 that can be connected end to end in series to form a solenoid when the flexible circuit board is formed into a cylinder.
  • the individual traces 72, 74 are connected by placing the connection on the inner layer of the board in electrical contact with the traces on the outer layer of the board.
  • Each antenna is connected to pads on the inner layer of the board (pad 1 A- pad 2C) via traces (trace 1 A - trace 2E).
  • the pads on the inner layer of the board are used to connect each antenna to a transmission line housed within a discrete lumen as hereinafter described.
  • the design of the traces allows the traces to act as pads for placing electrical components in series with and/or parallel to the antenna.
  • trace 1(2)A can be connected to trace 1(2)D and trace 1(2)D can be connected to trace 1 (2)E via surface mount components.
  • capacitors 56, 58, 60, 62, 64, 66 may be used to form a matching network between each antenna 52, 54 and its associated transmission line.
  • FIGS. 10-14 show the printed circuit board in its cylindrical configuration. The openings 80, 82 in the board shown in FIGS. 10-14 allow the extrusion covering the coils to bond to the support structure under the printed circuit board.
  • a novel multi-lumen design is also used to address challenges associated with integrating transmission lines into a dilator and ensuring their robustness.
  • Transmission lines are fragile due to their size, filters, connection points, etc.
  • Using a dedicated lumen protects the transmission lines from possible tension placed on the line and interference with other components that may be housed in the interventional device, such as a dilator.
  • the interventional device 10 such as a dilator, includes a shaft having a lumen that comprises a base larger single lumen extrusion 11.
  • the extrusion 11 may be made from high density polyethylene (HDPE) or a similar material.
  • the base lumen extrusion may be regularly or irregularly formed depending on how many smaller lumens are desired.
  • a second smaller extrusion constructed from a different material such as a polyimide and like materials, as best seen in FIG. 2, is coaxially assembled with the larger extrusion.
  • FIG. 2 illustrates how the two extrusions are assembled coaxially to create a lumen having three dedicated lumens.
  • the inner lumen 14 is depicted as circular but those of skill in the art will appreciate that it may take any shape.
  • the inner lumen 14 may be used to accept a device such as a transseptal needle.
  • polyimide for the inner lumen has the benefit of limiting or eliminating potential particulate generation that can arise from advancing a needle through the lumen.
  • the two dedicated outer lumens 16, 18 may be used as channels for transmission lines for two antennas which may be positioned at the distal end of the assembly.
  • placing the transmission lines in an enclosed, dedicated lumen within the dilator allows the antennas to be placed at the distal end of the device without increasing the size of the device or degrading the device performance. Allowing the transmission lines to move within the lumens increases the robustness of the assembly and eliminates the risk that the transmission lines will snap or break due to tension placed thereon when the sheath and/or dilator are deflected.
  • FIG. 3 is an isometric view of the extrusion assembly showing the separately extruded inner lumen 14 for placement of a transseptal needle and the two separate outer lumens 16, 18 for placement of the transmission lines.
  • the lumens are formed by coaxially assembling the small inner extrusion 14 within the larger extrusion 11.
  • FIGS. 4-9 show the progression of the assembly of a trackable dilator 10 and its shaft.
  • Transmission lines are placed in the outer lumens 16, 18, the tip support 20 includes a flex printed circuit board antennas 22 in co-axial relationship with inner lumen 14, the dilator tip 24 is coupled to the tip support by means known to those of skill in the art, and a thin extrusion or cover 26 is placed over the tip support 20 and the PCB antennas 22.
  • FIGS. 8 and 9 illustrate variations to the larger extrusion profile of FIG. 1 allowing for three outer lumens within the dilator shaft. Those of skill in the art will appreciate that while three outer lumens are shown, any number of outer lumens may be used depending on the application.
  • the smaller, transseptal needle lumen 14 is again shown in co-axial relationship with the outer extrusion.
  • FIG. 9 shows an assembly with four outer lumens 34, 36, 38, 40 and a single transseptal needle lumen 14.

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  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Molecular Biology (AREA)
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Abstract

La présente invention concerne un dispositif interventionnel, tel qu'un dilatateur détectable comprenant une gaine orientable. Le dilatateur détectable comprend une tige à gaine orientable comportant une première partie extrudée et une seconde partie extrudée. La première partie extrudée présente une superficie de section transversale supérieure à une superficie de section transversale de la seconde partie extrudée. Les première et seconde parties extrudées sont formées dans une relation co-axiale. Les première et seconde parties extrudées forment une pluralité de lumières isolées servant à loger des composants du dispositif interventionnel.
PCT/US2016/012271 2015-01-08 2016-01-06 Dispositif interventionnel orientable détectable WO2016112066A1 (fr)

Applications Claiming Priority (2)

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US201562101127P 2015-01-08 2015-01-08
US62/101,127 2015-01-08

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WO2016112066A1 true WO2016112066A1 (fr) 2016-07-14

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080024375A1 (en) * 2006-07-28 2008-01-31 Martin Francis Rajesh Virtual fm antenna
US20130131496A1 (en) * 2009-06-16 2013-05-23 MRI Interventions, Inc. Mri-guided catheters
US20140135745A1 (en) * 2011-12-15 2014-05-15 Imricor Medical Systems, Inc. Mri compatible handle and steerable sheath

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080024375A1 (en) * 2006-07-28 2008-01-31 Martin Francis Rajesh Virtual fm antenna
US20130131496A1 (en) * 2009-06-16 2013-05-23 MRI Interventions, Inc. Mri-guided catheters
US20140135745A1 (en) * 2011-12-15 2014-05-15 Imricor Medical Systems, Inc. Mri compatible handle and steerable sheath

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