Patent Description:
Typical circuits utilize a positive and negative pole and thus typically require two sets of wires for a supply and return path for current. Circuit systems used with catheters also utilize such an arrangement, or utilize the patient himself as the ground. The typical arrangement utilizes sets of wires running from the proximal to the distal end of the catheter.

<CIT> discloses systems and methods for reducing the number of temperature measurement wires in multiple temperature sensor ablation systems. In a preferred embodiment, temperature sensors capable of measuring the temperature of body tissue and transmitting the temperature data digitally are incorporated in a catheter or probe ablation system that also includes electrodes in operative contact with the sensors. The sensors are connected in parallel to a common electrical bus, thereby allowing the system to operate using a reduced number of electrical paths as compared to conventional ablation systems. The present invention is also directed to ablation systems that incorporate analog sensors rather than digital sensors. In this embodiment, the system utilizes digital switching, filtering circuits, or oscillators to reduce the number of wires required to operate the sensors.

In one embodiment a circuit system utilizes a terminal bank and one or more sensors which feed off the terminal bank.

In another embodiment a circuit system utilizes a voltage source, a terminal bank, and one or more sensors which connect to the terminal bank.

In another embodiment a circuit system utilizes a hypotube, where the hypotube includes a terminal bank and one or more sensors.

In another embodiment a braided catheter utilizes some of the wires comprising the braid to convey current in a circuit.

In another embodiment a braided catheter utilizes some of the wires comprising the braid to convey signals in a circuit.

In another embodiment a braided catheter utilizes some of the constituent wires comprising the braid to convey current to a terminal bank.

In another embodiment a braided catheter utilizes some of the constituent wires comprising the braid to convey current to a terminal bank, where one or more sensors are connected to the terminal bank.

In another embodiment, a braided catheter comprises multiple wires where some of the constituent wires comprising the braid are used to link to a terminal bank.

In another embodiment, a braided catheter comprises multiple wires where some of the wires are used as a supply and return path for a circuit and some of the wires convey a signal.

In another embodiment, a braided catheter comprises multiple wires where some of the wires are used as a supply and return path for a circuit and some of the wires convey a signal between one or more sensors and a user interface.

In another embodiment, a braided catheter comprises a hypotube.

In another embodiment, a braided catheter comprises a hypotube, where the hypotube contains a terminal bank.

In another embodiment, a braided catheter comprises a hypotube, where the hypotube contains a terminal bank and one or more sensors.

In another embodiment a powered catheter includes a hypotube.

In another embodiment a circuit includes a hypotube, where the hypotube contains a terminal bank and one or more sensors.

In another embodiment a powered catheter includes a hypotube, where the hypotube contains a terminal bank and one or more sensors.

In another embodiment a powered catheter includes a variable coil detachment system.

In another embodiment a powered catheter includes a catheter distal tip detachment system.

In another embodiment a powered catheter includes a steerable guidewire system.

These and other aspects, features and advantages of which embodiments of the invention are capable of will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which:.

It should be understood that a variety of different embodiment and/or variations on components are described herein. It is the intention of this application that each of these embodiments and components can be used and/or interchanged with each other. Therefore, while a specific embodiment may not specify a feature of another embodiment described herein, such a combination is contemplated and included in the present disclosure.

<FIG> illustrates a catheter <NUM> (or alternately a microcatheter) that delivers power and data through structural wires that make up the elongated tubular portion <NUM> of the catheter <NUM>. The catheter <NUM> is connected to an interface <NUM> that provides power and/or data to and from the catheter via a cable <NUM>. By allowing the structural wires to be used for power/data, the catheter size or diameter can be minimized. Additionally, a plurality of electrically powered components (e.g., sensors) and even circuitry are used in the distal end 11A (or other locations) in the catheter <NUM>.

While some of the embodiments of the present invention may be described in terms of powering and obtaining data from electrical components such as sensors, it should be understood that a variety of different powered elements are possible. For example, heater coils, mechanical latches, and similar powered implant detachment mechanisms can be powered according to the present invention. In other examples, other powered elements may include imaging systems, pressure sensing, temperature sensing, and oxygen sensing.

<FIG> illustrates a plurality of braided structural wires <NUM> that are part of the elongated tubular portion <NUM> of the catheter <NUM> that terminate with and connect to a distally located receptacle <NUM>. These wires <NUM> provide structural support to the elongated tubular portion <NUM> and are also used to deliver electrical power and/or data to the proximal end of the catheter <NUM>. The braid of <FIG> is comprised of <NUM> wires (18A-18F) braided in a tubular shape. The braided wires <NUM> can be located in several different positions as part of the elongated tubular portion <NUM>, such as <NUM>) on an outer surface of the tubing of the elongated tubular portion <NUM>, <NUM>) "sandwiched" between two or more layers of the tubular portion <NUM> (i.e., not exposed on an interior or exterior of the tubing), and <NUM>) located along the inner surface of the tubular portion <NUM> so as to be exposed to the interior passage of the tubular portion <NUM>.

In one embodiment shown in <FIG>, the braided structural wires <NUM> are a metal material <NUM> that is structurally suitable for a catheter (e.g., nitinol or stainless steel) and are coated with a highly conductive layer <NUM> (e.g., gold) and then coated in an electrical insulation <NUM> (e.g., polyamide).

In another embodiment shown in <FIG>, the braided structural wires <NUM> comprising the tubular braid are made entirely of a conductive material <NUM> (e.g., gold) in order to efficiently convey the current/signal, and further includes an electrically insulating coating <NUM> preventing discharge of the current/signal while it is being conveyed. While the wires <NUM> are depicted as having a round or circular cross section in <FIG>, other shapes are also possible, such as relatively flat, oval, rectangular, and square.

<FIG> illustrates an abstract schematic diagram of an example circuit system having four electrical components (26A-26D) and a plurality of structural wires <NUM>. Each electrical components 26A-26D is connected to two wires that are connected to a positive and negative terminal of a power source in the interface <NUM>, which thereby supplies power to the electrical components. In this respect, the <NUM> wire example shown in <FIG> can be used to power all of the electrical components and to communicate data back to the interface <NUM>. Similarly, a <NUM> wire braid would allow <NUM> electrical components, and a <NUM> wire braid would allow <NUM> electrical components since each electrical components would require <NUM> wires <NUM> to complete the circuit. In this respect, any number of wires can be used, such as <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>.

<FIG> illustrates an embodiment according to the invention of a circuit configuration in which only two of the wires <NUM> provide power via a positive and negative voltage source (e.g., battery) of the interface <NUM>. The wires connect to separated electrical terminals <NUM> and <NUM> which are located at or near the distal end 11A of the catheter <NUM>. The electrical components 26A-26D are each connected to these terminals <NUM>, <NUM> via wires <NUM> (or any other electrical path), allowing power to be supplied from the interface <NUM> to each of the electrical components.

The data or signal from each of the electrical components 26A-26D is then conveyed from the electrical components to the user interface via one of the braided wires <NUM> of the catheter <NUM>. In this way, for example, an <NUM>-wire braid can utilize up to <NUM> electrical components instead of <NUM> electrical components. Similarly, a <NUM>-wire braid could utilize up to <NUM> electrical components (two wires used for the positive and negative terminal connection, and the balance of the wires used to connect each electrical components), a <NUM>-wire braid could utilize up to <NUM> electrical components, and so on.

It should be understood that some electrical components (such as sensors) require only two power wires to operate and send back data (e.g., such as a thermistor in which changes in resistance on the wires is measured), while other electrical components or sensors require one or more additional wires to convey data (e.g., three wires total). As such, the number of wires used in each of these embodiments also depends on the type of electrical components used.

The user interface <NUM> preferably acts as a point of control for the user (e.g., press a button 16A) to effect an outcome at the other end of the system (e.g., detach an implant or a distal portion 11A of the catheter <NUM>). Where the electrical components are used for sensing the physiological conditions of the vessel (e.g., pressure or temperature), the user interface may have a display 16B (as well as the underlying CPU/microprocessor, memory, and software to process data and drive the display) indicating the particular physiological condition which is observed. The user interface <NUM> also preferably contains the voltage source for the circuit, in one example via a battery with a positive and negative terminal.

According to the invention, the terminal banks and electrical components configuration of <FIG> are formed by a hypotube located near the distal end of a catheter <NUM>, similar to receptacle <NUM> of <FIG>. This can be visualized by taking the circuit concept of the distal part of the circuit of <FIG> (i.e. the left side of the figure, comprising the terminal banks <NUM>, <NUM> and electrical components 26A-26D) and configuring it into a cylindrical or circle shape. <FIG> illustrates a hypotube representation <NUM> of such a circuit. The hypotube <NUM> contains a plurality of notched or cut-out areas <NUM> which the distal end of the braid wires <NUM> connect to and/or otherwise mate within. The wires <NUM> of the braid can be welded or otherwise electro-mechanically joined to the cut-out sections <NUM> to create a snug connection with the hypotube <NUM>.

The hypotube <NUM> may also contain embedded circuitry <NUM>. This circuitry <NUM> may connect to the electrical components 26A-26D, so as to provide additional functionality and/or processing of electrical components signals. This circuitry <NUM> is connected to the positive and negative voltage terminal banks <NUM>, <NUM>, as indicated by element <NUM> in <FIG>, so as to obtain power for the circuitry <NUM>.

The hypotube <NUM> may be cut (e.g., laser cut) into a pattern to include the cut-out sections <NUM>. The hypotube <NUM> is preferably made of materials which are highly conductive, have high mechanical strength, and allow for easy termination/connectivity of other wires and materials. In one example, the hypotube is comprised of a gold plated polyimide and additional laser cuts can be performed to help shape the path of the different electrical paths/circuits. Once a first series of cuts are created, the hypotube is coated with an electrically isolating material, such as parylene, which also acts to bond the circuit paths where the laser cut was made. Parylene strikes a balance between conformal coating properties and high tensile strength, however other materials exhibiting similar characteristics may also be used. Additional laser cuts can be further made to complete any necessary electrical/circuit paths. The parylene insulation may also help hold the hypotube together, thus the circuit cuts are completed after the insulation is added to the preliminary circuit cuts. Once the circuit route is completed, another round of Parylene coating is undertaken to fully encapsulate the component. A final laser cutting process is undertaken where the coating is removed or ablated at key locations in order to allow for the addition of additional wires as resistors within the circuit paths. The hypotube <NUM> in this form functions in a similar manner to a traditional printed circuit board.

The hypotube circuit can be used for a number of purposes. For example, components can be added to the hypotube <NUM> itself to allow for signal conditioning or processing at the site of an electrical components instead of at the user interface. In one example, small wires of various resistive properties can be added to create a Wheatstone bridge to increase sensor accuracy. An operational amplifier could also be integrated on the hypotube circuit <NUM> to improve sensor values.

A wire (e.g., a catheter structural braid wire <NUM>) connects the sensor to the proximal user interface to relay the signal. Much of the signal processing or signal conditioning could be done on the hypotube circuit itself through the methods discussed. Alternatively or additionally, signal processing could also be done on the user interface.

The hypotube <NUM> may also include a number of signal processing elements, such as operational amplifiers, signal filtering, etc. as part of the circuit <NUM>. One advantage of doing the signal processing in the hypotube <NUM> itself instead of in the user interface <NUM> is that the user interface resources could be freed up for other purposes. Additionally, since signals may degrade when conveyed over a distance, the signal can be cleaned up at the distal part of the system before being sent back to the user interface <NUM>, thus reducing the effect of signal degradation on system operation.

One advantage of the circuit concept, as described earlier, is that the circuit <NUM> and its connection to one or more of the electrical components <NUM> is completed at the distal portion 11A of the catheter <NUM>, instead of allowing each of the electrical components <NUM> to have its own wires <NUM> connected to the interface <NUM>. Hence, the catheter tube <NUM> may be formed to have a relatively smaller outer diameter.

The electrical components <NUM> may be used for a number of functions, such as an imaging system, pressure sensing, temperature sensing, oxygen sensing, or any number of additional systems used with powered catheters/microcatheters. The electrical components may also be used as part of an embolic coil detachment system, and/or a detachable catheter tip system, and/or a steerable guidewire system.

<FIG> and <FIG> illustrate an alternate structure for a hypotube <NUM>, similar to that of the hypotube <NUM>. In this respect, the hypotube <NUM> includes one or more notches 32A and a plurality of elongated finger contacts 32B that are each angled or bent inwardly into the hypotube <NUM>. In this respect, power can be supplied to the contacts 32B which, when in contact with electrical contacts on an inner catheter or pusher can cause the catheter or pusher to perform a function, such as detach an implant via a heater or mechanical mechanism.

<FIG> illustrate one example use of a hypotube <NUM> having contacts 32B used to detach an embolic coil <NUM> similar to that disclosed in <CIT>. The hypotube <NUM> includes a distal power terminal <NUM> and a proximal terminal <NUM> that are connected to one or more distal or proximal contacts 32B, respectively. The embolic coil <NUM> has one or more detachment points <NUM> at select locations along the coil <NUM>. When the electrical contacts 32B align with the embolic coil <NUM> and the detachment point <NUM> the interface <NUM> may indicate or display the alignment. Once the user has received an alignment signal, a desired action can be actuated, such as pressing a button to initiate detachment of the coil <NUM> at the detachment zone <NUM> from the pusher <NUM>. Since the hypotube <NUM> can support multiple electrically powered components, a sensor 32C may also be included on the hypotube <NUM>, providing functionality such as detachment detection, temperature sensing, or imaging.

<FIG> and <FIG> illustrate a more specific example of the detachment point <NUM> of the embolic coil. Two conductive cylinders or sleeves <NUM> and <NUM> are mated to a proximal and distal end of an insulating sleeve <NUM> via adhesive or glue. The conductive sleeves <NUM> and <NUM> are composed of a conductive material, such as a <NUM>/<NUM> ratio platinum/tungsten material.

Heater <NUM>, which can be a coil of wire, spans the area between the proximal and distal conductive sleeves <NUM> and <NUM>, connecting its ends to each of the sleeves, allowing current to pass through each of the components. Hence, when properly aligned with the proximal and distal contacts 32B of the hypotube <NUM> and current is applied, the heater coil <NUM> will increase in temperature, melting the adhesive of the insulating sleeve and causing the distal portion of the embolic coil <NUM> to detach. Springs <NUM> and <NUM> allow for attachment of a monofilament or tether to help prevent stretching of the embolic coil. In an alternate embodiment, a tether may connect between the two springs <NUM>, <NUM> so as to hold the two segments of the embolic coil <NUM> together and therefore can be broken by the heater <NUM> to cause detachment.

In another one example similar to that disclosed in <NUM>/<NUM>,<NUM>, a steerable guidewire system utilizes spaced positive and negative electrical contacts on a hypotube, similar to that describe in <FIG> which electrically interact with a bimetallic guidewire to angle a distal end of the guidewire to enable navigation of the guidewire through the vasculature.

As previously discussed, the hypotube <NUM> and its circuitry can be used to power a heater coil in the catheter <NUM>. In one example <FIG> disclose a catheter <NUM> having a detachable distal end tip 11A that is similar to the embodiments disclosed in <CIT>. The hypotube <NUM> is located at a distal portion of the elongated tubular portion <NUM> and an adhesive <NUM> maintains the distal end tip 11A to the elongated tubular portion <NUM>. The user can initiate a detachment sequence (e.g., push a button on the interface <NUM>) to activate the heater <NUM> and melts the adhesive <NUM> to effect detachment of the distal end tip 11A of the microcatheter <NUM> for various reasons (e.g., during delivery of a liquid embolic where there is danger of the distal tip 11A of the catheter getting glued into the vasculature). Similar to the previous example, the hypotube <NUM> connects to the braided structural wires <NUM> and provides electrical pathways to the heater <NUM>. In this example, the heater <NUM> may be located adjacent to or even be connected to the inner surface of the hypotube <NUM>.

<FIG> illustrates an alternate embodiment of the hypotube <NUM> of <FIG>, but instead of connecting to a single heater <NUM>, the hypotube <NUM> connects to a proximal heater coil 49A, a middle heater coil 49B, and a distal heater coil 49C. The hypotube <NUM> can be connected to three discrete pairs of wires <NUM> and electrical paths on the hypotube <NUM>, allowing each of the heater coils to be individually activated.

<FIG> illustrates a hypotube <NUM> with multiple heater coils <NUM>, similar to that of <FIG>, except that the coils are located parallel and adjacent to each other. In this regard, the hypotube <NUM> may be located either in a catheter or within a pusher sized for movement within a catheter.

Alternately, the user interface may contain multiple batteries, allowing multiple terminal banks on the hypotube which are connected to the multiple batteries. In another alternative, multiple batteries are used, allowing one battery to provide the terminal bank and the other batteries are selectively used for particular systems (i.e. one battery solely used to power the terminals for the variable coil detachment system, and/or one battery solely used to power the terminals for the detachable tip catheter system). Thus, for example, there could be one positive contact and two negative contacts spaced out at different intervals to interact with the different systems. Similarly, there may be one negative contact and two positive contacts spaced apart at different intervals to interact with the different systems. In one example, the electrical components could control the operation of the exact system in use (i.e. variable detachment, detachable tip, steerable guidewire, or another system) via the integrated circuitry on the hypotube and the signal which is sent to the user interface via the wire braid, as discussed earlier. In another example, the distal hypotube electrical components would be unnecessary if the braid wires are solely used to convey current from the battery as opposed to a signal from electrical components. In this example, the user interface itself would have the circuitry for the various systems and the wires which are used to convey the current between the proximal and distal ends of the catheter are also used to convey the signal from the user interface (i.e. convey the signal input to detach the embolic coil, or detach the catheter tip, or deflect the guidewire tip).

The embodiments and systems described herein offer many advantages in creating a powered catheter system. The following is a non-exhaustive list. One of the main advantages of the system is using the catheter braid itself to convey current, thus providing a useful secondary benefit to the catheter braid besides structural reinforcement of the catheter. Another advantage of the system is using two of the catheter braid wires to power the terminal banks on the hypotube at the distal end of the catheter, and having the electrical components directly connect to the terminal banks on the hypotube itself, thus only requiring one wire to connect the electrical components to the user interface since the electrical components are powered on the hypotube itself. Another advantage of the system is utilizing the distal hypotube as a circuit system, and the ability to allow signal processing to be done on the hypotube itself via the integrated circuitry, instead of at the proximal end of the system. Signals can degrade over a long distance, so offering signal processing at the source of the signal offers some advantages in and of itself. Another advantage is the ability to combine several powered catheter functionalities without requiring a large number of wires to convey all the signals.

In other embodiments, the system described herein would not need a separate negative terminal source and the patient himself could be used as the ground to complete the circuit. Thus, in one example, the proximal part of the system would just contain a positive charge source, a wire would run the current to the distal end of the system and the patient himself would comprise the ground. The distal end of the system would still utilize all the circuitry with the electrical components, but this would allow for an additional electrical component since only one wire would be needed to convey the current since the patient provides the ground.

In other embodiments, an alternate current voltage source could be used instead of a direct current voltage source.

In other embodiments, the wiring for the catheter system would not utilize a catheter braid (i.e. if the catheter does not utilize any braiding) but consists of wires which are external or internal to the catheter surface, or integral between layers of the catheter tubing. In other embodiments reinforcement coil(s) or ribbon(s) could be used instead of a braid.

In other embodiments not covered by the claimed invention, the terminal banks could be replaced with a capacitor. The capacitor could then store the charge from the voltage source.

The embodiments described include a circuit system. The circuit system can be used on a number of devices including interventional devices, including a catheter or microcatheter or other delivery device.

The embodiments described utilize the structural reinforcement layer of a catheter (generally described as a braid) to conduct current between two ends of the catheter. Though the term braid is used, the term should be interpreted broadly so as to describe any structural layer, thus the term braid may include coils, ribbons, and other structural components commonly used in catheters.

Claim 1:
A catheter comprising:
an elongated tubular portion (<NUM>) having a proximal end and a distal end;
a plurality of wires (<NUM>) extending between said proximal end and said distal end;
a circuit system located near the distal end of the elongated tubular portion (<NUM>), the circuit system comprising:
a hypotube (<NUM>) located at the distal end of said elongated tubular portion (<NUM>);
a positive terminal bank (<NUM>) and a negative terminal bank (<NUM>) formed by the hypotube (<NUM>); and
a plurality of electrical components (26A-26D) that are each connected to the positive terminal bank (<NUM>) and the negative terminal bank (<NUM>) so as to power each of the plurality of electrical components (26A-26D);
wherein the hypotube (<NUM>), the positive terminal bank (<NUM>), the negative terminal bank (<NUM>), and the plurality electrical components (26A-26D) are configured into a cylindrical shape; and
an interface (<NUM>) connectable to said proximal end of said elongated tubular portion to supply power to plurality of electrical components, the interface (<NUM>) including a positive voltage source and a negative voltage source, wherein the positive voltage source is electrically connectable to the positive terminal bank (<NUM>), and the negative voltage source is electrically connectable to the negative terminal bank (<NUM>), via two of said plurality of wires.