Abstract:
A remote control catheterization system ( 20 ) includes a propelling device ( 28 ), which controllably inserts a flexible, elongate probe ( 26 ) into the body of a patient ( 22 ). A control console ( 34 ), in communication with the propelling device, includes user controls ( 38, 40 ) which are operated by a user of the system remote from the patient to control insertion of the probe into the body by the propelling device.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to invasive medical probes and methods, and specifically to intravascular catheterization and catheterization techniques. 
     BACKGROUND OF THE INVENTION 
     Catheterization procedures are very commonly performed for diagnosis and treatment of diseases of the heart and vascular system. The catheterization procedure is generally initiated by inserting a guide wire into a blood vessel in the patient&#39;s body. The guide wire is then guided to the desired location, most commonly in one of the heart vessels or elsewhere in the vascular system. At this point the catheter is slid over the guide wire into the blood vessel and/or heart. Once the catheter is in the desired position, the guide wire can then be removed, leaving the catheter in location. Alternatively, in some procedures, the catheter is inserted without using a guide wire. The catheter may be used to pass ancillary devices into the body, such as an angioplasty balloon, or to perform other diagnostic or therapeutic procedures. 
     In order to facilitate the guide wire insertion and the subsequent catheter application, the physician generally performs the procedure with the assistance of a fluoroscope, as is well known in the art. The fluoroscope produces a real-time image showing the continued progress of the guide wire, or the catheter, through the patient&#39;s body. 
     The fluoroscope generates a high level of X-ray radiation, which poses a significant danger to medical personnel exposed thereto, as is well known in the art. In order to provide protection from radiation exposure, the attending medical personnel generally wear a heavy, cumbersome protective lead garment which covers the entire body and neck, or use various lead shields including transparent glass face and eye shields. 
     SUMMARY OF THE INVENTION 
     It is an object of some aspects of the present invention to provide apparatus and methods of catheterization that allow medical personnel to be distanced from the vicinity of the fluoroscope and its resultant radiation, thereby reducing radiation exposure of the personnel. 
     It is a further object of some aspects of the present invention to provide a mechanism for remote control performance of catheterization procedures. 
     In preferred embodiments of the present invention, a remote control catheterization system feeds an intravascular catheter into the body of a patient. The system is preferably used to perform substantially all aspects of a catheterization procedure, including insertion of a guide wire in preparation for catheter insertion and therapeutic and/or diagnostic treatments using the catheter. The system is operated by a physician who observes a fluoroscopic image of the procedure on a remote fluoroscope screen, preferably outside the room in which the patient is located, and controls the procedure using a remote control console. 
     In some preferred embodiments of the present invention, the physician inserts a cannula into the patient&#39;s blood vessel and inserts a guide wire through the cannula into the body, in a manner known in the art. The proximal portion of the guide wire is fed through a propelling device, which feeds the guide wire into the vessel while providing steering and speed control. The propelling device is controlled by the physician using the remote control console. 
     Once the guide wire has been inserted to a desired location, for example within a coronary artery, the physician passes a catheter over the proximal end of the guide wire. The proximal portion of the catheter is then placed in the propelling device, which feeds the catheter over the wire, similarly under the physician&#39;s control using the console. The feeding device may then be used similarly to control the catheter inside the body and to pass ancillary devices, such as an angioplasty balloon, through the catheter. 
     In some preferred embodiments of the present invention, the propelling device comprises one or more propelling mechanisms, preferably three such mechanisms, one for each of the guide wire, catheter and ancillary device. In one such preferred embodiment, each of the propelling mechanisms comprises two wheels, preferably fabricated from a rigid non-corrosive material, such as PVC. The distance between the wheels is adjustable to the accommodate the width of the guide wire, catheter or ancillary device, as applicable. The wheels are driven by a small motor, as is well known in the art, which is controlled by the physician using the remote control console. 
     Although it is most convenient to use three separate propelling mechanisms, in an alternative preferred embodiment of the present invention, the propelling device comprises only one propelling mechanism. The sole propelling mechanism comprises two adjustable wheels as described above, a motor, and applicable gauges. Once the guide wire has been inserted to a desired position within the body, the guide wire is removed from between the wheels of the propelling mechanism, and the catheter or ancillary device is threaded into the propelling mechanism, as applicable. 
     In other preferred embodiments of the present invention, the propelling mechanism may comprise a robot arm, or any other suitable manipulation mechanism known in the art. 
     In preferred embodiments of the present invention, the physician receives feedback, preferably both tactile and visual feedback, indicative of the force needed to insert the guide wire, catheter or ancillary device. This feedback alerts the physician if an obstruction or other obstacle has been encountered. In the preferred embodiment described above, torque gauges are preferably coupled to the motor to measure the reverse force applied to the guide wire, catheter or ancillary device during insertion, and thus provide the feedback. Additionally, a rotor gauge is preferably coupled to the guide wire, catheter or ancillary device to measure and verify its speed of advance. 
     Preferably, the torque gauges or other force-measuring devices are coupled to a safety mechanism, which halts the insertion if the gauge reaches a predetermined force threshold. 
     The torque measurement, along with the measured speed, are relayed to the remote console situated outside of the catheterization room. The physician at the console thereby has at his command substantially all the information needed to control the procedure: the fluoroscope display, the reverse force measurement, and the measurement of the advance speed. This information enables the physician to perform the guide wire insertion, as well as catheter insertion and other diagnostic or therapeutic procedures, as applicable, via remote control, substantially without exposure to X-ray radiation. 
     In some preferred embodiments of the present invention, the remote control console comprises a steering device, preferably a joystick. The speed and direction of motion of the propelling device are controlled by the direction and extent to which the physician displaced the joystick from its center, “zero” position. Preferably, the reverse force measurement is fed back to the joystick, so that the greater the resistance encountered by the guide wire, catheter or ancillary device, the greater is the force required to displace the joystick. 
     Although preferred embodiments are described herein with reference to cardiac catheterization procedures, it will be appreciated that the principles of the present invention may similarly be applied to other medical procedures that are performed using fluoroscopic visualization, for example, non-cardiac catheterization or angioplasty, and other radiological procedures involving the use of catheters under fluoroscopy. 
     There is therefore provided, in accordance with a preferred embodiment of the present invention, a remote control catheterization system including: 
     a propelling device, which controllably inserts a flexible, elongate probe into the body of a patient; and 
     a control console, in communication with the propelling device, and including user controls which are operated by a user of the system remote from the patient to control insertion of the probe into the body by the propelling device. 
     Preferably, the propelling device includes wheels which roll against the elongate probe in one direction to advance the elongate probe, and in the reverse direction to retract the elongate probe. Alternately or additionally, the propelling device includes an arm which grasps and pushes the probe to advance it, and grasps and pulls the probe to retract it. 
     Preferably, the propelling device includes a rotating mechanism, which rotates the probe about a longitudinal axis thereof. Preferably, the rotating mechanism includes rollers which roll against the elongated probe. 
     Preferably the propelling device includes a motor which drives the insertion of the probe. 
     Preferably, the propelling device includes a force sensor which measures a force applied during insertion of the elongate probe, most preferably, including a torque gauge which measures a torque required to move the elongate probe. 
     Preferably the control console receives force measurements from the force sensor and provides tactile feedback responsive thereto to the user. 
     Preferably the propelling device includes a movement sensor for measuring a linear advance of the elongate probe. 
     Preferably, the system includes a fluoroscope which produces a real-time image showing the progress of the elongate probe in the patient&#39;s body, which is displayed on the control console. Most preferably, the console includes a display which receives and displays data relating to the propelling device. 
     Preferably, the user controls includes a joystick for tactile control of the propelling device. 
     There is additionally provided, in accordance with a preferred embodiment of the present invention, a method for catheterization including: 
     inserting an elongate, flexible probe into a body passage; 
     feeding a portion of the probe outside the body into a propelling device, which advances the probe through the body passage; and 
     controlling the propelling device to advance the probe from a location remote from the body. 
     Preferably, feeding the portion of the probe includes feeding the probe between wheels which roll against the probe to advance it. Additionally or alternately, feeding the portion of the probe includes grasping the probe with an arm which pushes the probe to advance it. 
     Preferably, feeding the portion of the probe includes feeding the probe into a rotating mechanism, which rotates the probe about a longitudinal axis thereof, most preferably including feeding the probe between rollers which roll against the probe to rotate the probe around its longitudinal axis. 
     Preferably, controlling the propelling device includes controlling a motor which drives the insertion of the elongate probe. 
     Preferably, controlling the propelling device includes measuring a force applied to move the elongate probe, most preferably by measuring a torque. 
     Preferably, controlling the propelling device includes measuring a linear advance of the elongate probe. 
     Preferably, controlling the propelling device includes displaying a fluoroscopic image showing progress of the elongate probe in the patient&#39;s body. 
     Preferably, controlling the propelling device includes receiving measurements relating to the propelling device and displaying the measurements on the control console. Preferably, controlling the propelling device includes operating a joystick, most preferably, including receiving tactile feedback relating to the propelling device. 
     Preferably, inserting the elongate probe includes inserting a guide wire and inserting the elongate probe over the guide wire. Additionally or alternatively, the method includes inserting an ancillary device through the elongate probe. 
     Preferably, inserting the elongate probe includes inserting a catheter into a blood vessel. 
     In a preferred embodiment, controlling the propelling device includes controlling the device to advance the catheter to the heart. 
    
    
     The present invention will be more fully understood from the following detailed description of the preferred embodiments thereof, taken together with the drawings in which: 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a simplified, pictorial illustration of a system for remote control catheterization, in accordance with a preferred embodiment of the present invention; 
     FIG. 2 is a schematic illustration of a catheter propelling device, for use in the system of FIG. 1, in accordance with a preferred embodiment of the present invention; 
     FIG. 3 is a schematic illustration showing details of a catheter propelling mechanism, for use in the propelling device of FIG. 2, in accordance with a preferred embodiment of the present invention; and 
     FIG. 4 is a schematic illustration showing details of a catheter propelling mechanism, in accordance with an alternative embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Reference is now made to FIG. 1, which is a simplified, pictorial illustration of a remote control catheterization system  20 , in accordance with a preferred embodiment of the present invention. System  20  comprises a guiding catheter  26 , which is fed via a cannula  42  into a blood vessel  44  leading to a target location in a vessel or a heart  24  of a patient  22 . Preferably, the catheter is fed over a guide wire, which is omitted in FIG. 1 for simplicity but shown in detail in FIG. 2, below. 
     Catheter  26  is fed through a catheter propelling device  28 , and then coupled proximally with a catheter interface  30 . As shown In FIG. 1, device  28  may be opened for insertion of the catheter and other elements and, optionally, for manual override of the operation of the device, as described further hereinbelow. Interface  30  may be used to perform various therapeutic and/or diagnostic catheter procedures, such as balloon inflation or injection of contrast media, or any other such catheter-based treatments known in the art. A fluoroscope  32  is used to capture images showing the position of catheter  26  in the patient&#39;s body. (For simplicity, the X-ray tube associated with the fluoroscope is not shown in the figure.) 
     Propelling device  28 , interface  30  and fluoroscope  32  all communicate with a control console  34 . The various elements of system  20  relay operative information to console  34 , and receive operative instructions from the console. Preferably, device  28  relays to console  34  force measurements associated with insertion of the catheter and an indication of the distance that the catheter has traveled; interface  30  relays applicable data from the catheter regarding the therapeutic and/or diagnostic procedures being performed; and fluoroscope  32  conveys X-ray images. 
     The data are preferably displayed on console  34  via a pair of displays, monitors  36 . Preferably, one of monitors  36  displays fluoroscopic images, and the other monitor displays data received from propelling device  28  and interface  30 . Alternatively, the data may be presented using dials, meters, or any means known and used in the art. 
     Console  34  also includes a user-interface peripheral device  38  and a tactile control unit  40 . Medical personnel operating system  20  use device  38 , preferably a keyboard, to send directional commands, for example to control table and fluoroscope motions, and to operate interface  30  and fluoroscope  32 . Control unit  40 , preferably a joystick with tactile and speed feedback, as described herein below, sends directional and speed instructions to propelling device  28 . 
     In order to prevent exposure by medical staff to the fluoroscope&#39;s high levels of radiation, console  34  is preferably located outside of the catheterization room or in an area of the room that is shielded from radiation generated by the fluoroscope X-ray tube. The present invention, via this usage of remote control communication with console  34 , thus furnishes the medical staff with all the relevant information, and all the relevant remote control means, to perform the catheterization operation without danger of radiation exposure. 
     Alternatively or additionally, console  34 , or certain elements thereof, may be in a remote location, even in a different city from the patient, and communicate with the other elements of system  20  over telecommunication channels. For example, in addition to displaying images to the operating staff in a room adjacent to the catheterize operation, the same images can be relayed in parallel to medical colleagues or trainees in locations further away from the catheterization room. In yet another preferred embodiment, the present invention enables the entire catheterization procedure, including actions taken by medical staff in controlling the procedure, to be visually recorded via a visual recording device for post-operative observation or analysis. 
     FIG. 2 is a schematic illustration showing details of catheter propelling device  28 , for use in the system of FIG. 1, in accordance with a preferred embodiment of the present invention. As noted above with reference to FIG. 1, cannula  42  is inserted into blood vessel  44 . Preferably a guide wire  46  is threaded through cannula  42  into vessel  44 . Once guide wire  46  is in a desired position, catheter  26  is slipped over guide wire  46  and guided to a desired position, for example, in one of the chambers of heart  24  or in one of the coronary arteries. Once catheter  26  is in place, guide wire  46  may be withdrawn if desired. An ancillary instrument  48 , such as an angioplasty balloon, may be passed through the catheter, into the heart or arteries. The guide wire, catheter and ancillary instrument are themselves substantially similar to devices of these types known in the art. The present invention provides novel apparatus and methods for inserted these devices, as well as other invasive probes and instruments known in the art. 
     As shown in FIG. 2, propelling device  28  comprises one or more propelling mechanisms, preferably three such mechanisms  50 ,  52  and  54 . Propelling mechanism  50  provides the feeding force which advances catheter  26  through vessel  44 . Propelling mechanism  52  provides feeding force to instrument  48 , and propelling mechanism  54  provides feeding force to guide wire  46 . The operation of these mechanisms is described in greater detail with reference to FIG. 3, below. 
     A controller  56  provides drive signals and direction to mechanisms  50 ,  52  and  54 . Additionally, control  56  receives feedback from the mechanisms regarding the insertion force and speed of catheter  26 , wire  46  or instrument  48 , as applicable, as described in greater detail hereinbelow. Controller  56  is coupled in a closed loop to console  34 , conveying to console  34  the force and speed feedback and receiving from console  34  instructions to be passed on to mechanisms  50 ,  52  and  54 . 
     Although device  28  is preferably driven by controller  56 , the medical staff may optionally halt the remote operation of device  28  by controller  56 , and may manually override the operation of mechanisms  50 ,  52  and  54  to insert catheter  26 , wire  46 , or instrument  48 , as applicable. 
     FIG. 3 is a schematic illustration showing details of mechanism  50 , shown in FIG. 2, in accordance with a preferred embodiment of the present invention. Mechanism  50  is described herein by way of example, and it will be understood that mechanisms  52  and  54  operate in a substantially similar manner. Furthermore, although propelling device  28  is shown in FIG. 2 as comprising three mechanisms  50 ,  52 , and  54 , for catheter  26 , ancillary device  48  and guide wire  46 , respectively, a single mechanism such as mechanism  50  could be used, albeit less conveniently, to advance the guide wire, catheter and ancillary device in turn. 
     Mechanism  50  comprises two wheels  62  and  66 , which engage catheter  26  and rotate either in the forward direction, as shown by the arrows in the figure, to advance the catheter through vessel  44 , or backward to retract catheter  26 . Additionally, mechanism  50  preferably comprises two rollers  63  and  67  located on an axis 90° from that of wheels  62  and  66 , which engage catheter  26  and rotate it around its longitudinal axis, preferably by at least ±180°, as shown by the arrows in the figure. The distance between wheels  62  and  66 , and between  63  and  67 , is preferably adjustable to accommodate the width of catheter  26 , or of wire  46  or ancillary device  48 . 
     A rotary motor  60 , preferably a reversible stepper motor or servo motor, as are known in the art, is coupled to drive wheel  62 , preferably via a belt  64 . The belt is preferably coupled to motor  60  via a non-slip hub. Wheel  66 , located on the opposite side of catheter  26 , is preferably free turning, and rotates as driven by the motion of the catheter. In a similar manner, a rotary motor  61  is coupled to drive roller  63  via a belt  65 . Roller  67 , located on the opposite side of catheter  26 , operates similarly to wheel  66 . 
     Upon completion of the catheterization procedure, or whenever it is necessary to move the catheter back proximally during the procedure, the rotation of motor  60  is reversed, creating a clockwise rotation of wheel  62  and belt  64 , thereby retracting catheter  26 . 
     The force required to advance or rotate catheter  26  is monitored by a torque gauge  68  coupled to motor  60 , and by a torque gauge  69  coupled to motor  61 , respectively. For example, gauge  68  may measure the electrical current required by motor  60  to advance catheter  26 , and translates this current to a measurement of force. The force readouts from gauges  68  and  69  are relayed to controller  56  and from there, preferably, to console  34 . Alternatively, other types of force and torque sensors known in the art may also be used. When catheter  26  encounters an obstruction in vessel  44 , motor  60  or motor  61  will generally require greater current to achieve forward movement or rotate, respectively. Controller  56  preferably shuts off motor  60  or  61 , automatically when the current or other torque indication received by gauge  68  or  69 , respectively, reaches a predetermined maximum level. 
     Although in the preferred embodiment shown in FIG. 3, wheel  62  and roller  63  are driven and monitored by separate, respective motors and controllers, wheel  62  and roller  63  may alternatively be driven by a common motor, with appropriate gearing, and with a single force gauge. 
     Mechanism  50  preferably provides an additional level of safety by the usage of a movement sensor, such as a rotor gauge  70 . Rotor gauge  70  is coupled to a wheel  72  which is placed in contact with catheter  26 . Preferably, rotor gauge  70  measures the number of rotations of wheel  72 , thereby measuring the actual speed of movement and/or total cumulative advance of catheter  26 , independent of motor  60 . This information is then relayed to controller  56 , which passes the information on to console  34 . 
     As described above with reference to FIG. 1, the medical staff at console  34  are capable of remotely directing propelling device  28 , through controller  56 , using peripheral device  38  and tactile control unit  40 . Controller  56 , upon receipt of directions from console  34 , changes the current levels fed to motor  60  or  61 , thereby changing the speed of motor, as appropriate. Preferably, the torque measurements from torque sensor  68  are fed back to unit  40  as tactile feedback. For example, assuming unit  40  to comprise a joystick, as shown in FIG. 1, the more force needed to advance the catheter, the harder will it be to push the joystick forward to cause the catheter to advance. In addition, the torque and rotation readings, as well as other system parameters, are preferably displayed on one of displays  36 , as described above. 
     FIG. 4 is a schematic illustration showing details of catheter propelling mechanism  50 , in accordance with an alternative embodiment of the present invention. In this case, catheter  26  is advanced via a pushing motion and rotated via a twisting motion created by an arm  80 , which is driven by a motor unit  82 . All safety precautions supplied by torque gauges  68  and  69  and rotor gauge  70  are applicable to this alternate embodiment as well. The movement of arm  80  resembles the action performed by a physician in inserting a catheter by hand. Tactile control unit  40  in this preferred embodiment may also be designed so that the physician&#39;s interaction with the control unit is similar to the actions normally taken in advancing a catheter manually. 
     Although two preferred mechanisms for propelling catheter  26  are presented in FIGS. 3 and 4 (or for propelling guide wire  46  or ancillary device  48  as applicable), other propelling mechanisms may similarly be used. It will be appreciated generally that the preferred embodiments described above are cited by way of example, and the full scope of the invention is limited only by the claims.