Wireless catheter with base wireless transceiver

A medical probe, including a flexible insertion tube having a distal end for insertion into a body cavity and including one or more sensors mounted in the distal end, and a handle coupled to a proximal end of the insertion tube. The medical probe also includes a cable having a proximal end and a distal end, which is coupled to the handle so as to receive signals conveyed through the insertion tube from the one or more sensors, and a base unit coupled to the proximal end of the cable. The base unit contains a power source, and a probe wireless transceiver coupled to receive the signals from the cable and to communicate over a wireless connection with a control console.

FIELD OF THE INVENTION

The present invention relates generally to invasive probes, and specifically to producing an invasive probe fitted with a wireless transceiver.

BACKGROUND OF THE INVENTION

A wide range of medical procedures involve placing objects, such as sensors, tubes, catheters, dispensing devices and implants, within a patient's body. Position sensing systems have been developed for tracking such objects. Magnetic position sensing is one of the methods known in the art. In magnetic position sensing, magnetic field generators are typically placed at known positions external to the patient. A magnetic field sensor within the distal end of a probe generates electrical signals in response to these magnetic fields, which are processed in order to determine the position coordinates of the distal end of the probe. These methods and systems are described 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 International Publication WO 1996/005768, 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.

When placing a probe within the body, it may be desirable to have the distal tip of the probe in direct contact with body tissue. The contact can be verified, for example, by measuring the contact pressure between the distal tip and the body tissue. U.S. Patent Application Publications 2007/0100332, 2009/0093806 and 2009/0138007, whose disclosures are incorporated herein by reference, describe methods of sensing contact pressure between the distal tip of a catheter and tissue in a body cavity using a force sensor embedded in the catheter.

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.

SUMMARY OF THE INVENTION

There is provided, in accordance with an embodiment of the present invention a medical probe, including a flexible insertion tube having a distal end for insertion into a body cavity and including one or more sensors mounted in the distal end, a handle coupled to a proximal end of the insertion tube, a cable having a proximal end and a distal end, which is coupled to the handle so as to receive signals conveyed through the insertion tube from the one or more sensors. The probe includes a base unit coupled to the proximal end of the cable, and containing a power source, and a probe wireless transceiver coupled to receive the signals from the cable and to communicate over a wireless connection with a control console.

In some embodiments, the power source may be selected from a list including a battery, a power outlet and a wireless energy transfer system. In additional embodiments, the medical probe may include a spherical orb configured to house the base unit, and a socket configured to retain and allow a rotation of the spherical orb. In alternative embodiments, the medical probe may include a catheter holder configured to grasp the handle. In further embodiments, each of the one or more sensors may be selected from a list consisting of an electrode, a force sensor and a position sensor. In additional embodiments, the control console may include a console wireless transceiver and a processor configured to receive, via the wireless connection, measurement signals from the one or more sensors. In some embodiments, the medical probe may have no physical connection to the console. In additional embodiments, the medical probe may include one or more electrodes mounted on the distal end and coupled to the power source, and the probe wireless transceiver is configured to receive, via the wireless connection, an ablation signal from the processor, and the one or more electrodes are configured to perform an ablation on a wall of the body cavity responsively to the ablation signal.

There is also provided, in accordance with an embodiment of the present invention, a method, including inserting, using a handle coupled to a proximal end of a flexible insertion tube of a medical probe, a distal end of the flexible insertion tube into a body cavity, receiving, by a cable having a proximal end and a distal end which is coupled to the handle, signals, conveyed through the insertion tube, from one or more sensors mounted in the distal end of the insertion tube, and coupling a base unit to the proximal end of the cable, the base unit containing a power source, and a probe wireless transceiver coupled to receive the signals from the cable and to communicate over a wireless connection with a control console.

DETAILED DESCRIPTION OF EMBODIMENTS

Overview

Various diagnostic and therapeutic procedures, such as cardiac ablation and intracardiac electrical mapping, use an invasive probe, such as a catheter, whose distal tip is fitted with at least one electrode. The electrode is typically operated when the probe is pressed against a wall (also referred to herein as tissue) of a body cavity. In these procedures, it is usually important to ascertain both the precise location of the probe in the body cavity, and the force that the distal tip is exerting on the body cavity wall. Therefore, some catheters comprise position sensors for ascertaining the location of the distal tip and force sensors for measuring the force exerted by the probe on intra-body tissue, such as the endocardium.

Embodiments of the present invention form a “wireless catheter” by incorporating a wireless transceiver into the catheter, thereby reducing (and possibly eliminating) the number of physical links between the patient and a console. Since space limitations may preclude mounting the wireless transceiver and a power source in the catheter's handle, a base unit containing a transceiver-battery combination can be coupled to a proximal end of the handle by a cable.

In some embodiments, a fixture can be configured to hold a housing for the base unit and/or the handle. The fixture may include a holder where the operator can “park” the handle when the catheter is not being used. Additionally, the base unit housing can be configured as a spherical orb, and the fixture may include a socket configured to retain and allow a rotation of the spherical orb. The socket-orb configuration can function as a ball joint, within which the base unit is able to swivel, so that when the catheter holder is removed from the mount and manipulated, the cable does not restrict the motion of the handle.

Incorporating a wireless transceiver into a catheter system can help reduce clutter resulting from physical connections between the catheter and the console, thereby enhancing safety during a medical procedure. By eliminating the need for cabling between the catheter and the console, embodiments of the present invention can make it simple to add additional wireless catheters into an on-going procedure, rather than adding catheters requiring a physical connection to the console.

System Description

FIG. 1is a schematic pictorial illustration of a medical system20that implements wireless communication, in accordance with an embodiment of the present invention. System20may be based, for example, on the CARTO™ system, produced by Biosense Webster Inc. (Diamond Bar, Calif.). System20comprises a probe22, such as a catheter, and a control console24. In the embodiment described hereinbelow, it is assumed that probe22is used for diagnostic or therapeutic treatment, such as for mapping electrical potentials in a heart26or performing ablation of heart tissue. Alternatively, probe22may be used, mutatis mutandis, for other therapeutic and/or diagnostic purposes in the heart or in other body organs.

Probe22comprises a flexible insertion tube28, and a handle30coupled to the proximal end of the insertion tube. When probe22is not being used, handle30can be stored in a probe holder94of a fixture90, which may typically be affixed to a mounting bar98. The configuration of fixture90and mounting bar98are described in detail hereinbelow. By removing then manipulating handle30, operator32can insert probe22through the vascular system of a patient34so that a distal end36of probe22enters a chamber of heart26.

In the configuration shown inFIG. 1, multiple probes, each generally similar to probe22, can be stored in a corresponding multiple of fixtures, each generally similar to fixture90, affixed to mounting bar98. During a medical procedure, an operator32, such as a cardiologist, can select a given probe by removing its handle from its probe holder.

System20typically uses magnetic position sensing to determine position coordinates of distal end36inside heart26. Console24comprises a driver circuit40which drives field generators42to generate magnetic fields within the body of patient34. Typically, field generators42comprise coils, which are placed below the patient's torso at known positions external to patient34. These coils generate magnetic fields in a predefined working volume that contains heart26. A magnetic field sensor44within distal end36of probe22(sensor44is shown in more detail inFIG. 2) generates electrical signals in response to the magnetic fields from the coils, thereby enabling console24to determine the position of distal end36within the chamber.

Although in the present example system20measures the position of distal end36using magnetic-based sensors, other position tracking techniques may be used (e.g., impedance-based sensors). Magnetic position tracking techniques are described, for example, in U.S. Pat. Nos. 5,391,199 and 6,690,963 referenced above, and in in U.S. Pat. Nos. 5,443,489, 6,788,967, 5,558,091, 6,172,499 and 6,177,792, whose disclosures are incorporated herein by reference. Impedance-based position tracking techniques are described, for example, in U.S. Pat. Nos. 5,983,126, 6,456,864 and 5,944,022, whose disclosures are incorporated herein by reference.

A signal processor46processes these signals in order to determine the position coordinates of distal end36, typically including both location and orientation coordinates. The method of position sensing described hereinabove is implemented in the above-mentioned CARTO™ system and is described in detail in the patents and patent applications cited above.

Signal processor46typically comprises a general-purpose computer, with suitable front end and interface circuits for receiving signals from probe22and controlling the other components of console24. Processor46may be programmed in software to carry out the functions that are described herein. The software may be downloaded to console24in electronic form, over a network, for example, or it may be provided on non-transitory tangible media, such as optical, magnetic or electronic memory media. Alternatively, some or all of the functions of processor46may be carried out by dedicated or programmable digital hardware components.

A probe wireless transceiver48coupled to probe22is configured to communicate with processor40over a wireless connection via a console wireless transceiver50. For example, wireless transceivers48and50may comprise Bluetooth or Wireless Universal Serial Bus (USB) transceivers. Based on the signals received from probe22(via wireless transceiver50) and other components of system20, processor46drives a display52to present operator32with an image54showing the position of distal end36in the patient's body, as well as status information and guidance regarding the procedure that is in progress.

In the present embodiment, processor46monitors measurements received from position sensor44and a force sensor56within distal end36(force sensor56is shown in more detail inFIG. 2), typically during periods in which the catheter is believed to be pressing against endocardial tissue of heart26. Processor46stores data representing image54in a memory58. In some embodiments, operator32can manipulate image54using one or more input devices60.

Alternatively or additionally, system20may comprise an automated mechanism (not shown) for maneuvering and operating probe22within the body of patient34. Such mechanisms are typically capable of controlling both the longitudinal motion (advance/retract) of probe22and transverse motion (deflection) of distal end36of the probe. In such embodiments, processor46generates a control input for controlling the motion of probe22based on the signals provided by the magnetic field sensor in the probe.

AlthoughFIG. 1shows a particular system configuration, other system configurations can also be employed to implement embodiments of the present invention, and are thus considered to be within the spirit and scope of this invention. For example, the methods described hereinbelow may be applied using position sensors of types other than the magnetic field sensor described above, such as impedance-based or ultrasonic position sensors. The term “position transducer” as used herein refers to an element mounted on probe22which causes console24to receive signals indicative of the coordinates of the element. The position sensor may thus comprise a receiver on the probe, which generates a position signal to the control unit based on energy received by the sensor; or it may comprise a transmitter, emitting energy that is sensed by a receiver external to the probe. Furthermore, the methods described hereinbelow may similarly be applied in therapeutic and diagnostic applications using not only catheters, but also probes of other types, both in the heart and in other body organs and regions.

Other elements of system20illustrated inFIG. 1, such as a base unit70, are described in more detail below.

FIG. 2is a schematic sectional view of probe22, in accordance with an embodiment of the present invention. Specifically,FIG. 2shows functional elements of probe22and base unit70coupled to the probe. Base unit70comprises wireless transceiver48and a battery72. While the example inFIG. 2shows battery72as a power source, other power sources are considered to be within the spirit and scope of the present invention. For example, the power source may comprise a wired connection to either a battery external to the base unit or a standard alternating current (AC) power outlet. Alternatively, power can be conveyed to the probe via a wireless energy transfer system.

An ablation electrode74at a distal tip38of the probe is typically made of a metallic material, such as a platinum/iridium alloy or another suitable material. Alternatively, multiple electrodes (not shown) may be positioned along the length of the probe.

Position sensor44transmits a signal to console24that is indicative of the location coordinates of distal end36. Position sensor44may comprise one or more miniature coils, and typically comprises multiple coils oriented along different axes. Alternatively, position sensor44may comprise either another type of magnetic sensor, an electrode which serves as a position sensor, or position sensors of other types, such as impedance-based or ultrasonic position sensors. Although FIG.2shows a probe with a single position sensor, embodiments of the present invention may utilize probes with more than one position sensor.

In an alternative embodiment, the roles of position sensor44and magnetic field generators42may be reversed. In other words, driver circuit40may drive a magnetic field generator in distal end36to generate one or more magnetic fields. The coils in generator42may be configured to sense the fields and generate signals indicative of the amplitudes of the components of these magnetic fields. Processor46receives and processes these signals in order to determine the position coordinates of distal end36within heart26.

Force sensor56measures a force applied by distal tip38to the endocardial tissue of heart26by conveying a signal to the console that is indicative of the force exerted by the distal tip on the intra-body tissue. In one embodiment, the force sensor may comprise a magnetic field transmitter and receiver connected by a spring in distal end36, and may generate an indication of the force based on measuring the deflection of the spring. Further details of this sort of probe and force sensor are described in U.S. Patent Application Publications 2009/0093806 and 2009/0138007 referenced above. Alternatively, distal end36may comprise another type of force sensor.

Handle30is configured to be grasped by operator32, and is coupled to a proximal end76of insertion tube28and a distal end78of a cable80. A proximal end82of cable80is coupled to base unit70. The distal end of cable80is coupled to position sensor44, force sensor56and electrode74via a connection84that is contained within insertion tube28and handle30. While (for illustrative purposes)FIG. 2shows a single connection84coupling the electrode and the sensors to cable80, there are typically multiple connections contained within the insertion tube and the handle. Connection84typically comprises a metallic conductor and/or an optical fiber.

In operation, cable80receives signals from the position sensor, the force sensor and the electrode (when measuring electrical potentials values in the heart) that are conveyed through insertion tube28(i.e., via connection84). Wireless transceiver48receives the signals from cable80, and communicates the signals to console24over a wireless connection.

In some embodiments wireless transceiver48can be configured to receive wireless signals to control an ablation performed by electrode74. During an ablation procedure, processor46conveys, via the wireless connection, an ablation signal to probe22. Upon wireless transceiver48receiving the ablation signal, the probe performs the ablation by conveying an electrical current to electrode74.

FIGS. 3A and 3Bare schematic pictorial illustrations of fixture90that is configured to hold base unit70and handle30, in accordance with a first embodiment of the current invention. In the configuration shown inFIGS. 3A and 3B, base unit70is configured as a spherical orb that houses wireless transmitter48and battery72, and fixture90comprises a socket92, probe holder94and a clamp96. Clamp96can be used to affix fixture90to mounting bar98that is typically within reach of the operator. As shown inFIG. 1, multiple wireless probes can be made accessible to operator32by affixing multiple fixtures to mounting bar98.

Probe holder94is configured to grasp handle30when probe is not being used. Socket92is configured to retain spherical base unit70, and allow a rotation of the spherical base unit within the socket, so that the sphere rotating in the socket acts in a manner similar to a ball joint. In other words, when operator32removes handle30from holder94and manipulates the probe, the ball joint configuration of the sphere and the socket does not restrict the motion of the handle.

FIG. 3Cis a schematic pictorial illustration of a fixture100configured to hold base unit70, in accordance with a second embodiment of the present invention. In contrast to fixture90, fixture100holds only base unit70. In the configuration shown inFIG. 3C, a separate catheter holding fixture (not shown) can be used to grasp handle30.

Because of power capacity limitations of battery72, the wireless catheter may not be capable of relatively high power/high energy operation, such as is needed for an ablation procedure. In some embodiments, as described supra, electrical current can be conveyed from an external power source to probe22via a wired connection or a wireless energy transfer system that is incorporated into fixture90or100, and/or the mounting bar, thereby eliminating restrictions caused by the current being supplied by battery72.