Patent Publication Number: US-11660422-B2

Title: Catheter handle

Description:
PRIORITY 
     This application is a continuation application filed under 35 USC § 120 and claims the benefits of priority from prior filed U.S. patent application Ser. No. 15/815,394, now allowed, which prior application is hereby incorporated by reference as if set forth in full herein. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to catheters, and particularly to methods and systems for controlling deflection and shape of balloon catheters. 
     BACKGROUND OF THE INVENTION 
     Balloon catheters may be used in various medical procedures, such as in cardiac ablation. The balloon catheter is typically controlled remotely by a physician. Method and devices for controlling the operation of balloon catheters are known in the art. 
     For example, U.S. Pat. No. 9,579,448 describes a medical device for the treatment and irrigation of a sinus opening is described. The device allows for single-handed operation to access, dilate and irrigate a sinus opening. The device includes a sinus guide catheter, a guiding element, a balloon dilation catheter, a balloon catheter movement mechanism and a guiding element movement mechanism. 
     U.S. Pat. No. 6,221,070 describes a steerable ablation catheter system suitable for radiofrequency ablation of intra-cardiac tissue that comprises two parts: a disposable catheter shaft with a deflectable tip at the distal end of the shaft, and a handle with steering mechanisms. 
     SUMMARY OF THE INVENTION 
     An embodiment of the present invention that is described herein provides a medical instrument including first and second knobs. The first knob is fitted on a handle of the medical instrument, and is movable along a longitudinal axis of the medical instrument to control a deflection of a medical device coupled to a distal end of the medical instrument relative to the longitudinal axis. The second knob is fitted on the handle of the medical instrument, and is movable along the longitudinal axis to control a shape of the medical device. 
     In some embodiments, the first knob is configured to apply first and second levels of deflection of the medical device relative to the longitudinal axis of the medical instrument by being set at respective selected first and second positions along the longitudinal axis of the medical instrument. In other embodiments, the second knob is configured to set the medical device to first and second shapes by being set at respective selected first and second positions along the longitudinal axis of the medical instrument. In yet other embodiments, the first and second knobs are configured to operate independently of one another. 
     In an embodiment, at least one of the first and second knobs is movable, within a continuous range, along the longitudinal axis. In another embodiment, the handle includes a grip located in proximity to the first and second knobs, such that both the first and second knobs are accessible by one or more fingers of an operator hand that holds the grip. In yet another embodiment, the medical device is configured to be applied in a medical procedure selected from a list consisting of electrophysiology, ablation, sinuplasty, surgery, endoscopy, angioplasty, otolaryngology and neurology. 
     In some embodiments, the medical device includes an inflatable balloon catheter having an internal volume configured to receive inflation fluid. In other embodiments, the second knob is configured, when moved in a first direction along the longitudinal axis, to allow an inflation of the internal volume of the balloon catheter, and when moved in a second direction along the longitudinal axis, to deflate the balloon catheter by elongating the balloon and forcing the inflation fluid out of the internal volume. In yet other embodiments, the inflatable balloon catheter includes one or more electrodes coupled to an outer surface of the inflatable balloon catheter. 
     In an embodiment, the medical device includes at least one of electrodes and sensors coupled to the medical device at predefined positions, and at least one of the first and second knobs includes one or more markers indicative of the respective positions of the at least one of electrodes and sensors. In another embodiment, each of the one or more markers includes a respective number of an electrode or a sensor of the at least one of electrodes and sensors. 
     There is additionally provided, in accordance with an embodiment of the present invention, a method including inserting a medical device coupled to a distal end of a medical instrument into a patient organ. A deflection of the medical device, relative to a longitudinal axis of the medical instrument, is controlled by moving a first knob, which is fitted on a handle of the medical instrument, along the longitudinal axis. A shape of the medical device is controlled by moving a second knob, which is fitted on the handle of the medical instrument, along the longitudinal axis of the medical instrument. A medical procedure is conducted in the patient organ using the medical device. 
     The present invention will be more fully understood from the following detailed description of the embodiments thereof, taken together with the drawings in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic, pictorial illustration of a catheter-based tracking and ablation system, in accordance with an embodiment of the present invention; 
         FIGS.  2 A and  2 B  are schematic, pictorial illustrations of a balloon catheter control handle, in accordance with an embodiment of the present invention; and 
         FIG.  3    is a flow chart that schematically illustrates a method for conducting a medical procedure using a balloon catheter, in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Overview 
     Catheters are used, for example, in various interventional cardiology procedures, such as in treating arrhythmia, by ablating the heart tissue so as to form a lesion that blocks electrical conduction along a path of the heart tissue. A catheter used for ablation may comprise an inflatable balloon assembly having an array of devices, such as ablation electrodes, mounted on an outer surface of the balloon assembly. A catheter of this sort is referred to herein as a balloon catheter. 
     Embodiments of the present invention that are described hereinbelow provide improved techniques for controlling the operations of inflation and deflection of a balloon catheter. 
     During an ablation procedure, a physician typically starts with a deflated balloon for navigating the catheter to a target location in a patient heart. At the target location, the physician inflates the balloon so as to make physical contact between at least some of the ablation electrodes and heart tissue at the target location. In some cases, the physician may have to deflect the balloon assembly relative to the longitudinal axis of the catheter, so as to better reach the target tissue and/or improve the physical contact with the tissue. 
     In some embodiments, the catheter comprises a handle, which is coupled to the catheter proximal end, and which is configured to control the balloon assembly at the catheter distal end. At least first and second knobs are fitted on the handle and are movable along the longitudinal axis of the catheter. The first knob is configured to control a deflection of the balloon assembly relative to the longitudinal axis, and the second knob is configured to control the shape of the balloon catheter by elongating the balloon, thus collapsing it and forcing out inflation fluid through existing holes in the balloon. In some embodiments, the first and second knobs are configured to operate independently of one another, such that the physician may inflate or deflate the balloon assembly before or after deflecting the distal end of the catheter, or in any other suitable operational sequence. 
     In some embodiments, the level of inflation of the balloon assembly and the level of deflection of the distal end are each controllable in a continuous manner. In an exemplary sequence, the physician may deflect the distal end to its maximal deflection level after inflating a portion (e.g., half) of the internal volume of the balloon assembly, and subsequently, the physician inflates the balloon assembly to a fully inflated position. 
     The disclosed techniques improve the patient safety by providing the physician with easy control of the inflation and deflection operations of the balloon catheter using a single finger. When using the disclosed techniques, the physician can focus his or her attention on the essence of the procedure rather than on the technical manipulation of the balloon catheter. 
     Furthermore, the disclosed techniques may increase the success rate of ablation procedures by enabling accurate positioning of the ablation electrodes at the target locations of the tissue. 
     System Description 
       FIG.  1    is a schematic, pictorial illustration of a catheterization system  20 , in accordance with an embodiment of the present Invention. System  20  comprises a medical instrument, such as a balloon catheter  22 , and a control console  24 . In the embodiment described herein, catheter  22  may be used for any suitable therapeutic and/or diagnostic purposes, such as for ablating tissue or sensing electrophysiological (EP) signals from a heart  21  of a patient  28 . 
     In some embodiments, console  24  comprises a processor  34  having suitable front end and interface circuits for receiving signals from catheter  22 , and for controlling other components of system  20 . 
     In some embodiments, processor  34  typically comprises a general-purpose processor, which is programmed in software to carry out the functions described herein. The software may be downloaded to the computer in electronic form, over a network, for example, or it may, alternatively or additionally, be provided and/or stored on non-transitory tangible media, such as magnetic, optical, or electronic memory. 
     In some embodiments, console  24  further comprises a memory  38  and a display  46 , which is configured to display data, such as an image  44  of at least part of heart  21 . In some embodiments, image  44  may be acquired using any suitable anatomical imaging system. 
     Reference is now made to an inset  23 . A physician  30  inserts a shaft  25  through the vascular system of patient  28  lying on a table  29 . In some embodiments, catheter  22  comprises a balloon assembly  40  fitted at the distal end of shaft  25 . During the insertion of shaft  25 , balloon assembly  40  is maintained in a collapsed position by a sheath (not shown). By containing assembly  40  in the collapsed position, the sheath also serves to minimize vascular trauma along the way to a target location. 
     In some embodiments, physician  30  navigates balloon assembly  40  to the target location, such as a left atrium or another cavity of heart  21 , by manipulating shaft  25  using control handles  32  and  33  coupled to the proximal end of catheter  22 . 
     In some embodiments, physician applies handle  32  for controlling the navigation of shaft  25  and for manipulating the distal end of catheter  22 , e.g., so as to make contact between assembly  40  and tissue of heart  21 , as will be described in detail in  FIG.  2 B  below. Once the distal end of shaft  25  has reached the target location, physician  30  extracts assembly  40  out of the sheath, referred to herein as an “unextended position,” and allows a pump, such as an irrigation pump (not shown), to inflate balloon assembly  40  to an expanded position, as will also be described in detail in  FIG.  2 B  below. 
     In some embodiments, the proximal end of catheter  22  is connected to interface circuitry in processor  34 , and is described in further detail in  FIGS.  2 A and  2 B  below. 
     In some embodiments, the position of distal-end assembly  40  in the heart cavity is typically measured using position sensing techniques. This method of position sensing is implemented, for example, in the CARTO™ system, produced by Biosense Webster Inc. (Irvine, Calif.) and is described in detail in U.S. Pat. Nos. 5,391,199, 6,690,963, 6,484,118, 6,239,724, 6,618,612 and 6,332,089, in PCT Patent Publication WO 96/05768, and in U.S. Patent Application Publications 2002/0065455 A1, 2003/0120150 A1 and 2004/0068178 A1, whose disclosures are all incorporated herein by reference. 
     In some embodiments, console  24  comprises a driver circuit  41 , which drives magnetic field generators  36  placed at known positions external to patient  28 , e.g., below the patient torso. 
     In some embodiments, when the distal end of catheter  22  is positioned in the target location (e.g., the cavity of heart  21 ), physician  30  extracts balloon assembly  40  out of the sheath and applies handle  32  to manipulate assembly such that an outer surface of assembly  40  makes a physical contact with tissue of the cavity. 
     In some embodiments, balloon assembly  40  comprises an inflatable balloon (not shown) made from polyethylene terephthalate (PET), polyurethane, polyamide, or any other suitable flexible material. The inflatable balloon is configured to receive inflation fluid into an internal volume of balloon assembly  40 . 
     In some embodiments, physician  30  may apply handle  32  to bring balloon assembly  40  to a non-extended position and allow it to fill with the inflation fluid, or by using any other suitable inflation technique. The level of inflation determines the shape of assembly  40  so that, in some embodiments, handle  32  is configured to control the level of inflation as will be described in detail in  FIG.  2 B , as well as in the method described in  FIG.  3    below. 
     In some embodiments, handle  32  is further configured to control a deflection level of balloon assembly  40  relative to a longitudinal axis of catheter  22 . In case the contact between assembly  40  and the heart tissue is insufficiently firm, physician  30  may apply handle  32  to deflect assembly  40  so as to make improved contact between assembly  40  and the heart tissue. 
     In some embodiments, physician  30  may determine the levels of inflation and deflection of assembly  40  by setting one or more knobs (typically two knobs as shown in  FIGS.  2 A and  2 B ) of handle  32  to a selected position. 
     In some embodiments, the operations of inflation and deflection may be carried out separately (e.g., an inflation operation followed by a deflection operation), in parallel (e.g., setting both the shape of the balloon and the deflection level simultaneously), alternately (e.g., by setting an initial shape followed by initial deflection, and subsequently inflating (or deflating) assembly  40  to a final shape and deflecting again so as to better reach the target tissue and achieve the intended level of physical contact between assembly  40  and the heart tissue. In other embodiments, any other suitable sequence of operations, or a different combination of the operations described above, may be used. 
     In some embodiments, assembly  40  further comprises one or more electrodes  48  (ten electrodes in the example of  FIG.  1   ), coupled to the outer surface of assembly  40  and configured to exchange electrical signals with the proximal end of catheter  22  and to conduct the electrical signals to or from the tissue of heart  21 . During a medical procedure, such as cardiac EP mapping or tissue ablation, electrodes  48  are brought into contact with the tissue of heart  21 , so as to sense electrical signals originated therefrom, or to apply ablation signals for ablating the tissue as described above. 
     In the context of the present disclosure, the term “electrodes” refers to sensing electrodes or to ablating electrodes configured to sense electrical signals from heart  21  or to ablate tissue of heart  21 , respectively. 
     The configuration of system  20  shown in  FIG.  1    is an example configuration, which is chosen purely for the sake of conceptual clarity. In alternative embodiments, any other suitable configuration can also be used. For example, the size and shape of distal-end assembly  40 , and additional components, such as thermocouples and irrigation holes may be implemented in any suitable location in assembly  40 . 
     Controlling the Shape and Deflection of the Balloon Assembly 
       FIG.  2 A  is a schematic, pictorial illustration of handle  32  in a home position, in accordance with an embodiment of the present invention. 
     In some embodiments, handle  32  comprises a grip  45 , typically located at the proximal end of handle  32  and held by a hand of physician  30 . In the example of  FIG.  1    physician  30  holds handle  32  in one hand, and uses the other hand located near the end of the sheath to further control the movement. We generally assume that the physician holds the catheter by his or her right hand, but a left-handed person may hold the handle by the left hand. 
     In some embodiments, handle  32  comprises a deflection knob  50 , which is configured to move along a longitudinal axis (shown in  FIG.  2 B ) of catheter  22  so as to control the deflection of assembly  40  relative to the longitudinal axis of catheter  22 . In some embodiments, physician  30  may use the thumb (or one or more other fingers) of his or her right hand (i.e., the same hand holding the catheter handle) to advance knob  50 , so as to deflect assembly  40  relative to the longitudinal axis of catheter  22 . 
     In similar embodiments, physician  30  may use one or more fingers of his or her right hand to retract knob  50 , so as to align assembly  40  relative to the longitudinal axis of catheter  22 . 
     In some embodiments, handle  32  comprises a shape-control knob  60 , which is configured to control the shape of balloon assembly  40 . As described in  FIG.  1    above, physician  30  may apply control knob  60  to control the shape of assembly  40  by elongating the balloon of assembly  40 , thus collapsing it and forcing out the inflation fluid through existing holes in the balloon. 
     In some embodiments, physician  30  may control the shape of assembly  40  by moving shape-control knob  60  using one or more fingers in a similar manner as described above for deflection knob  50 . 
     Note that both deflection knob  50  and shape-control knob  60  are located in close proximity to grip  45 , such that when physician holds grip  45 , for example, using his or her right hand, each of deflection knob  50  and control knob  60  is accessible by one or more fingers (e.g., the thumb) of the same hand that holds grip  45 . 
     In the example of  FIG.  2 A , deflection knob  50  and shape-control knob  60  are fully retracted so that assembly  40  is not inflated and is substantially aligned with the longitudinal axis of catheter  22 . This position is referred to herein as a “home position,” which is the typical position of assembly  40  during introduction through the sheath. 
       FIG.  2 B  is a schematic, pictorial illustration of handle  32  in an extended position, in accordance with an embodiment of the present invention. In the context of the present disclosure and in the claims, the terms “expanded position”, “extended position” and “inflated position” are used interchangeably and refer to a position in which balloon assembly  40  is fully (or partially) inflated with the inflation fluid. 
     In some embodiments, physician  30  may move deflection knob  50  over a deflection setting range  52  along axis  49  of handle  32 , in directions represented by a two-way arrow  54 , so as to set the degree of deflection of assembly  40  relative to axis  49 . For example, physician  30  may move deflection knob  50  to one end of deflection setting range (e.g., the distal end), so as to obtain the maximal level of deflection of assembly  40 , and may similarly align assembly  40  with axis  49  by setting deflection knob  50  at the opposite (e.g., proximal) end of deflection setting range  52 . In some embodiments, the handle comprises mechanical stoppers at the ends of deflection setting range  52 . 
     In the example of  FIG.  2 A , deflection knob  50  is fully retracted to the proximal end of deflection setting range  52 , so that it makes contact with the mechanical stopper, such as the distal end of grip  45  that is configured to limit the motion of knob  50  within deflection setting range  52 . 
     In the example of  FIG.  2 B , knob  50  is fully advanced to the distal end of deflection setting range  52 , so that it makes contact with the mechanical stopper that prevents further deflection of assembly  40 . 
     In some embodiments, shape-control knob  60  is limited to move within a predefined range, referred to herein as a shape setting range  62  having, for example, a similar configuration and operational mode described above for the deflection setting range of deflection knob  50 . 
     In some embodiments, physician may advance shape-control knob  60  along shape setting range  62 , so as to extract the distal end of the balloon of assembly  40  to the unextended position, and to allow the irrigation pump to inflate the balloon with inflation fluid (not shown). In these embodiments, by sliding shape-control knob  60  forward to a certain position, physician  30  sets the shape of balloon assembly  40 . 
     In an embodiment, physician  30  may advance shape-control knob  60  along axis  49  in directions represented by a two-way arrow  64 , to the distal end of shape setting range  62  so as to set assembly  40  in an “inflated position.” 
     Similarly, physician  30  may retract shape-control knob  60  to the proximal end of shape setting range  62 , referred to herein as “home position” of knob  60  as shown in  FIG.  2 A . In the home position of knob  60 , the balloon of assembly  40  is elongated so that the inflation fluid is forced out of the internal volume of assembly  40 , e.g., into the body of patient  28 , or into a reservoir (not shown) of system  20 . 
     Note that, when deflection knob  50  and shape-control knob  60  are, each, positioned at the distal end of respective ranges  52  and  62 , assembly  40  is fully deflected relative to axis  49  and is fully inflated. This extended position typically assists physician  30  in manipulating assembly  40  to make the intended contact of the balloon catheter with the target tissue of heart  21 . 
     In some embodiments, deflection knob  50  can be positioned at any point along deflection setting range  52 . In alternative embodiments, deflection knob  50  can be set only at one or more predefined positions along the range. 
     In some embodiments, deflection knob  50  and shape-control knob  60  may be fitted on the distal end of grip  45  as shown in  FIG.  2 A , or may be coupled to handle  32  using any other suitable configuration and coupling technique. For example, deflection knob  50  and shape-control knob  60  may be fitted on handle  32  side-by-side instead of after one another along axis  49 . 
     In some embodiments, shape-control at least one of knobs  50  and  60  may have one or more numbers marked on the surface, as shown in  FIGS.  2 A and  2 B . In an embodiment, each number indicates a position of a respective electrode  48  on the outer surface of assembly  40 , so as to assist physician  30  in knowing the orientation of balloon assembly  40  in heart  21 , without relying on a mapping system or X-ray visualization. In other embodiments, the numbers, or any other suitable marker, may be used to indicate the position of any device, such as one or more electrodes and/or sensors coupled to the outer surface of assembly  40 . 
     In the example of  FIGS.  2 A and  2 B , deflection knob  50  and shape-control knob  60  are movable along respective linear ranges (e.g., deflection setting range  52  and shape setting range  62 ) along axis  49 . In alternative embodiments, at least one of these ranges may have a non-linear shape, such as a curved shape or any other suitable shape. For example, deflection knob  50  may control the deflection of assembly  40  by rotating, rather than by moving in a linear range. 
       FIG.  3    is a flow chart that schematically illustrates a method for conducting a medical procedure using balloon catheter  22 , in accordance with an embodiment of the present invention. The method begins at a catheter insertion step  100 , with physician  30  inserting catheter  22  into the body of patient  28  and navigating assembly  40  to the cavity of heart  21 . At a balloon inflation step  102 , physician  30  advances shape-control knob  60  towards the distal end of shape setting range  62 , unextending balloon and then inflates assembly  40  with the inflation fluid using the irrigation pump. 
     At a balloon deflection step  104 , physician  30  advances deflection knob  50  towards the distal end of deflection setting range  52 , so as to deflect assembly  40  relative to axis  49 . In some embodiments, physician  30  may check, after concluding each of steps  102  and  104 , whether assembly  40  makes the intended contact with the tissue of heart  21 . In case the intended contact is not obtained, physician  30  may repeat step  102  and/or step  104  until the intended contact between assembly  40  and the tissue is obtained. 
     After bringing assembly  40  into the intended contact with the tissue, physician  30  may carry out the medical procedure, such as ablating the tissue of heart  21 , at a treatment step  106 . In some embodiments, the medical procedure may involve diagnostics, such as sensing of EP signals from the tissue of heart  21 . 
     After concluding the medical procedure, physician  30  may align assembly  40  with axis  49  by retracting deflection knob  50  to the proximal end of deflection setting range  52 , at a distal end alignment step  108 . 
     At a deflating step  110 , physician retracts shape-control knob  60  to the proximal end of shape setting range  62 , so as to force the fluid out of the internal volume of assembly  40 , thereby to set assembly  40  in the unextended position. After concluding step  110 , handle  32  is set at home position as shown in  FIG.  2 A  above. 
     In some embodiments, physician  30  may change the order between steps  102  and  104 , or may apply any suitable sequence as described in  FIG.  2 B  above, so as to obtain, before applying the medical procedure at step  106 , the intended contact between assembly  40  and the tissue of heart  21 . 
     In some embodiments, after concluding the medical procedure at step  106 , physician  30  may change the order between steps  108  and  110 , or may apply any other suitable sequence, so as to set handle  32  at home position. 
     In some embodiments, after inflating balloon assembly  40  at step  100  physician  30  may extract balloon assembly  40  out of the sheath, as described in  FIG.  1    above. In some embodiments, after concluding step  110 , assembly  40  is in the unextended position and aligned with axis  49 . At this stage, physician  30  may insert assembly  40  into the sheath, thereby setting assembly  40  at a collapsed position. 
     At a retraction step  112 , physician retracts catheter  22  so as to extract assembly  40  out of the body of patient  28 . Step  112  concludes the method of  FIG.  3   . 
     Although the embodiments described herein mainly address cardiac arrhythmia, the methods and systems described herein can also be used in other applications, such as in electrophysiology, ablation of tissue, sinuplasty, surgery, endoscopy, angioplasty, otolaryngology and neurology. 
     It will thus be appreciated that the embodiments described above are cited by way of example, and that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and sub-combinations of the various features described hereinabove, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art. Documents incorporated by reference in the present patent application are to be considered an integral part of the application except that to the extent any terms are defined in these incorporated documents in a manner that conflicts with the definitions made explicitly or implicitly in the present specification, only the definitions in the present specification should be considered.