Patent Description:
Various techniques for applying a minimally invasive treatment to an intrabody tissue have been proposed in the patent literature. For example, <CIT> describes an apparatus and methods for pericardial access to perform a procedure therein. The apparatus includes a catheter including a tubular member comprising a proximal end, a distal end sized for introduction into a patient's body, an imaging assembly on the distal end, and a substantially transparent expandable member attached to the tubular member distal end. The imaging assembly is disposed within an interior of the expandable member, wherein the imaging assembly images tissue through a surface of the expandable member. The tubular member includes a drainage lumen communicating one or more drainage ports on the tubular member distal end proximal to the balloon for aspirating fluid from the patient's body. The catheter may be used to access a pericardial space and an ablation probe may be introduced through the catheter to treat heart tissue while fluid is infused and/or aspirated via the drainage ports.

As another example, <CIT> describes an interventional medical device that incorporates an imaging system and is minimally invasive. The device is equipped with an anchoring portion that may be slidable and fixed in a predetermined position of its elongate body outside the human body. The device further includes deployable first and second balloons for also securing the device to an internal wall, for example, within a human body. The medical device can be in the form of a catheter, a sheath, or comprise interventional devices, particularly those suitable for minimally invasive procedures in the pericardium. The dual sealing/locking balloons may comprise a slidably moveable assembly for moving from a first position over an inflation channel to a second position over an inflation channel for separately inflating a distal balloon and then a proximal balloon to the patient's skin surface. Alternatively, the balloon assembly may be fixed over first and second inflation/deflation channels from the proximal end. The imaging system comprises one or more ultrasound transducers disposed proximate to the distal end and/or on the sides of an elongate body portion and so can be used to guide the device to a target area, guide the inflation of the deployable balloons and guide the performance of a procedure and/or provide visual access to a target area for performing a procedure via a plurality of lumens.

<CIT> describes a pericardiocentesis apparatus and method for accessing the pericardial Space. The invention consists of inserting a percutaneous tube whose tip has a hole which is positioned over and contacts the anterior pericardium. Introducing a vacuum within the tube forms a pericardial bleb within that hole. A guided needle within the tube is advanced to puncture the pericardial bleb while avoiding contact with the epicardium. A hollow filament or electrocardial lead or flexible guide wire within the needle can then be advanced into the pericardial cavity. The guide wire may be used to guide an intrapericardial catheter into the pericardial space for injection or infusion of selected therapeutic agents into the pericardial space to treat various heart and blood vessel diseases. Controlled drug release material(s) can be injected through the needle for the slow and/or sustained delivery of the therapeutic agents into the pericardial cavity.

<CIT> discloses an access device for guiding instruments to a region within a human body, the access device comprising: a shaft comprising a proximal end and a distal end, the shaft defining a lumen comprising channels extending longitudinally between the proximal end and the distal end, the channels comprising an instrument channel, a balloon inflation channel, and a guide wire channel; a head attached to the distal end of the shaft, the head comprising a top surface, a bottom surface opposite the top surface, and a port configured to allow an instrument extended through the instrument channel to interact with the region of the human body; a camera attached to the head and commutatively coupled to a camera cable extending through the shaft, the camera oriented to capture images of the region of the human body; and a balloon attached to the top surface of the head and in fluid communication with the balloon inflation channel.

The invention is defined in independent claim <NUM>, with further embodiments defined in the dependent claims.

An embodiment of the present disclosure provides a medical probe including a shaft, a camera, a hollow cutting tool, and an inflatable balloon. The shaft is configured for insertion through a cut in a body of a patient, whereas the shaft includes a working vacuum channel running therethrough. The camera is fitted at a distal end of the shaft and is configured to provide images of a target tissue site in the body. The hollow cutting tool is for insertion over a guidewire in the working vacuum channel of the shaft, whereas the hollow cutting tool is configured to pierce the target tissue site under guidance of images taken by the camera. The inflatable balloon is configured to stabilize the distal end of the shaft, whereas the inflatable balloon is located proximally to the camera so as not to obstruct the images of the target tissue site.

In some embodiments, the target tissue site includes a pericardium site and wherein the shaft is configured for insertion through a cut in a chest of the patient.

In some embodiments, the medical probe further includes a second probe, which is configured to be inserted via the working vacuum channel for treating a target tissue location, whereas the camera is additionally configured to provide images of treatment by the second probe.

In an embodiment, the second probe is also configured to serve as a deflectable guidewire for the medical probe.

In another embodiment, the second probe includes an ablation catheter.

In some embodiments, the inflatable balloon is configured to stabilize both the medical probe and the second probe.

In some embodiments, the target tissue location includes a myocardium location.

There is additionally provided, in accordance with an embodiment of the present disclosure, a method including inserting, through a cut in a body of a patient, a medical probe including a shaft having a working vacuum channel running therethrough, a camera fitted at a distal end of the shaft, and an inflatable balloon located proximally to the camera. A hollow cutting tool is inserted over a guidewire via the working vacuum channel, for piercing the target tissue site under guidance of images taken by the camera. The guidewire is retracted. A second probe is inserted via the working vacuum channel. The balloon is inflated so as to stabilize the medical probe and the second probe. A target tissue location is treated using the second probe under guidance of the images taken by the camera.

Pericardial treatment, such as radiofrequency (RF) ablation, may be used to alleviate heart problems, such as certain types of ventricular arrhythmias as well as some atrial fibrillations. However, pericardial ablation applied to an outer surface of the myocardium may have limited success, due in part to the presence of epicardial fat. The fat layer may prevent proper RF energy delivery by, for example, causing inadequate contact of the ablation catheter with muscle tissue. In addition, because of the existence of significant amounts of epicardial fat, any ablation energy that is intended for the myocardium may instead be absorbed by the fat, which has a substantially lower conductivity compared to the myocardium. Pericardial ablation may also be limited by increased likelihood of other complications, such that may arise because of energy delivery in close proximity to coronary vessels.

Embodiments of the present invention that are described and shown hereinafter provide a camera-guided medical probe (e.g., catheter, also referred herein as a "first probe") to enable controlled access and treatment of target tissue in the body, such as the myocardium. The embodiments described herein provide a camera-guided pericardium catheter comprising a second probe, which can access and treat the outer surface of the myocardium. The disclosed pericardium catheter is inserted into the patient through a small incision in the chest, and is navigated to the pericardium using the camera. Once the catheter is in position immediately outside the pericardium, the treating physician inserts a hollow cutting tool over a guidewire through a working channel of the catheter in order to, under guidance by images taken by the camera, pierce the pericardium, including piercing its fatty epicardial sub-layer. The camera assists the physician to avoid collateral damage in the process, such as accidently piercing the myocardium itself with the hollow cutting tool.

In the context of the disclosed description the term "hollow cutting tool" represents any tool that is inserted through a working channel of the pericardium catheter and used for performing a cut in the pericardium, e.g., a tool having a form of a needle, a blade or a cutting laser.

In some embodiments, the working channel additionally serves as a vacuum channel configured to lift the pericardium to facilitate its incision by the hollow cutting tool with minimum risk to the myocardium underneath.

The guidewire is than advanced through the incision in the pericardium and the hollow cutting tool is withdrawn, and the catheter is pushed over the guidewire through the incision in the pericardium. Once catheter is inside the pericardium, the guidewire retracted and the second probe, typically an RF ablation catheter, is inserted into the working channel and, again using the camera, is navigated to a desired region, such as a target body tissue (i.e., myocardium) location.

In some embodiments, the medical probe comprises an inflatable balloon, which is typically used during the subsequent ablation procedure and kept collapsed during incision. The balloon is typically located proximally to the camera, so as not to obscure a field of view comprising a forward line of sight (e.g., a cone of sight) between the camera and target tissue site (i.e., pericardium) for the incision. Subsequently, when inflated, the balloon stabilizes the pericardial catheter and the second probe by pushing against the epicardium layer from one end of the balloon and the myocardium from the other end.

In an embodiment, the pericardium catheter is constructed to be more flexible than the second probe, whereas the second probe can be deflected, so that the second probe, in addition to performing its treatment function (e.g., RF ablation), acts as a deflectable guidewire.

The disclosed camera-guided pericardium catheter may decrease risks of a minimally invasive pericardial treatment as well as potentially improving the clinical outcome of myocardium treatment, such as ablation.

<FIG> is a schematic, pictorial illustration of a system <NUM> for minimally invasive pericardial treatment comprising a pericardial catheter <NUM>, in accordance with an embodiment of the present invention. A physician <NUM> inserts a shaft <NUM> of pericardial catheter <NUM> through a sheath <NUM> into the thorax of a patient <NUM>, in the vicinity of a heart <NUM>, through a cut in the chest of patient <NUM>. Then physician <NUM> manipulates the pericardial catheter so that a distal end <NUM> of shaft <NUM> of the catheter, seen in inset <NUM>, approaches pericardial sac <NUM> and cuts through it to access myocardium <NUM>. The cut is made for the purpose of subsequently inserting a second, treatment probe, such as an ablation catheter to ablate the area underneath myocardium <NUM>.

In order to obtain access to myocardium <NUM>, distal end <NUM> is fitted with a hollow cutting tool <NUM>, which is advanced distally through a working channel in pericardial catheter <NUM>. However, as noted above, cutting through pericardium sac <NUM>, and in particular a fatty epicardium sub-layer <NUM> of pericardium sac <NUM>, may result in collateral damage, such as hollow cutting tool <NUM> puncturing myocardium <NUM> and even penetrating into a cardiac cavity <NUM>.

In order to carefully and accurately guide hollow cutting tool <NUM>, physician <NUM> uses a camera <NUM>, which is located at distal end <NUM>, to provide an image <NUM> (e.g., video image) of pericardium <NUM> during the cutting procedure. The video image of pericardium <NUM> is presented to physician <NUM> on a display <NUM>. To clear the field of view of camera <NUM>, for example from blood, an irrigation pump <NUM> supplies fluid, such as saline solution, that washes the lens of camera <NUM>. The clearing fluid flows via a lumen in catheter <NUM> to distal end <NUM> and exits from a tube <NUM>.

As an additional means to avoid collateral damage, such as puncturing myocardium <NUM>, physician <NUM> operates a vacuum channel <NUM>, so as to lift the epicardium off of the myocardium, as described below. Channel <NUM> is connected to a vacuum pump <NUM> in console <NUM> via a cable tube <NUM>.

After performing the cut in pericardium <NUM>, hollow cutting tool <NUM> is retracted and a second probe, such as an ablation catheter (seen in <FIG>) is advanced through the same, or a different, working channel of pericardial catheter <NUM>, as described below, to treat myocardium <NUM>.

In an embodiment, the ablation catheter is inserted, under the guidance of camera <NUM>, through the pericardium cut in the vicinity of a myocardium location for ablation. After verifying that the ablation catheter tip is in contact with the myocardium at the targeted myocardium location, by using images captured by camera <NUM>, physician <NUM> performs the RF ablation.

For performing the RF ablation, physician <NUM> actuates an RF energy generator <NUM> in a control console <NUM> to supply RF energy via a cable <NUM> to distal end <NUM>. A temperature sensor (not shown in the figures) in distal end <NUM> may provide feedback to console <NUM> for use in controlling the RF energy dosage and/or flow rate of cooling irrigation.

<FIG> is a schematic, pictorial illustration of the pericardial catheter <NUM> of <FIG>, in accordance with an embodiment of the present invention. As seen, hollow cutting tool <NUM> protrudes beyond the distal edge of distal end <NUM>, and is seen in proximity to pericardium sac <NUM> and epicardium layer <NUM> underneath. Hollow cutting tool <NUM> is inserted through vacuum channel <NUM> that serves also as a working channel (seen in a cross-section <NUM> of catheter <NUM>). Vacuum channel <NUM> is configured to lift both layers <NUM> and <NUM> to facilitate their incision by hollow cutting tool <NUM> with minimum risk to myocardium <NUM> located underneath. The entire incision process is guided using camera <NUM> having a cone of sight <NUM> to provide images of hollow cutting tool <NUM> in relation to target pericardium tissue. Illumination to camera <NUM> is provided by one or more light sources <NUM>, such as fiber optics bundles, or LEDs covered with diffusive optics.

An inflatable balloon <NUM>, seen collapsed, is fitted distally to camera <NUM>, so as not to block cone of sight <NUM>. The balloon is subsequently inflated and collapsed using a fluid channel <NUM>.

The example illustration shown in <FIG> is chosen purely for the sake of conceptual clarity. <FIG> shows only parts relevant to embodiments of the present invention. Other system elements, such as additional sensors fitted over distal end <NUM> are omitted. Catheter <NUM> may also include several additional working channels.

<FIG> is a schematic, pictorial illustration of distal end <NUM> of the pericardial catheter of <FIG>, in accordance with an embodiment of the present invention. As seen, an ablation catheter <NUM> having an ablation electrode <NUM> is inserted via vacuum/working channel <NUM>, in order to ablate target tissue <NUM> over myocardium <NUM>. Ablation catheter <NUM> is further configured to serve as a deflectable guidewire for catheter <NUM>. Balloon <NUM> is inflated to stabilize catheters <NUM> and <NUM> during the procedure (e.g., by stabilizing distal end <NUM> of shaft <NUM>). Camera <NUM> provides visual images of electrode <NUM> in relation to target myocardium location <NUM> to guide the RF ablative treatment.

The example illustration shown in <FIG> is chosen purely for the sake of conceptual clarity. Other system elements, such as another type of second probe, such as for infusion of medication, may be inserted through a working channel. Irrigation may be applied during ablation to target myocardium location <NUM> through another channel in pericardium catheter <NUM>.

<FIG> is a flow chart that schematically illustrates a method for manufacturing distal end <NUM> of <FIG>, in accordance with an embodiment of the present disclosure.

The process begins with fitting camera <NUM> to distal end <NUM>, in a way that the camera has a free line of sight distally to the distal end, at a camera fitting step <NUM>. Next, optical light sources <NUM> (e.g., illumination fiber bundles or LEDs) are fitted to distal end <NUM>, at an optical fibers fitting step <NUM>. Finally, expandable balloon <NUM> is fitted to distal end <NUM>, proximally to camera <NUM>, so as not to disrupt camera <NUM> line of sight.

The example flow chart shown in <FIG> is chosen purely for the sake of conceptual clarity. Only manufacturing steps relevant to embodiments of the present disclosure are shown.

<FIG> is a flow chart that schematically illustrates a method for minimally invasive pericardial treatment, in accordance with an embodiment of the present disclosure. The process begins with physician <NUM> inserting pericardium catheter <NUM> into the thorax of patient <NUM>, to bring distal end <NUM> in the vicinity of heart <NUM>, at a pericardium catheter insertion step <NUM>. Next, physician <NUM> applies vacuum via channel <NUM>, so as to lift pericardium sac <NUM> and epicardium sub-layer <NUM>, at a pericardium lifting step <NUM>. Using images that camera <NUM> provides, physician <NUM> applies hollow cutting tool <NUM> over guidewire <NUM> to cut the lifted pericardium, at a pericardium incision step <NUM>.

At a cutting tool retraction step <NUM>, physician <NUM> retracts hollow cutting tool <NUM> over guidewire <NUM>.

Next, physician <NUM> advances distal end <NUM> over guidewire <NUM> to bring collapsed balloon <NUM> under epicardium sub-layer <NUM>, at a pericardium catheter advancement step <NUM>.

Once distal end <NUM> of catheter <NUM> is advanced sufficiently beyond the pericardium sac, physician <NUM> inflates balloon <NUM> to stabilize both catheters, at a balloon stabilizing step <NUM>.

At a tool replacement step <NUM>, physician <NUM> retracts guidewire <NUM> and inserts ablation catheter <NUM> through vacuum/working channel <NUM>. Next, using camera <NUM>, which has clear line of sight to myocardium <NUM>, physician <NUM> navigates ablation catheter <NUM> to bring electrode <NUM> in contact with target myocardium <NUM> location <NUM>, at an ablation catheter navigation step <NUM>. Physician <NUM> may use catheter <NUM> as a deflectable guidewire to, if required, further slide over catheter <NUM>, for example, to further stabilize the catheters. Finally, physician <NUM> ablates myocardium location <NUM>, at an ablation step <NUM>.

The example flow chart shown in <FIG> is chosen purely for the sake of conceptual clarity. In alternative embodiments, for example, physician <NUM> may additionally apply irrigation and measure tissue temperature.

Although the embodiments described herein mainly address cardiac applications, the methods and systems described herein can also be used in other applications, such as in minimally invasive camera guided surgery.

Claim 1:
A medical probe (<NUM>), comprising:
a shaft (<NUM>) configured for insertion through a cut in a chest of a patient (<NUM>), wherein the shaft comprises a working vacuum channel (<NUM>) running therethrough to the distal edge of the distal end (<NUM>) of the shaft, wherein the shaft defines a longitudinal shaft axis, and wherein the working vacuum channel extends along the longitudinal shaft axis;
a camera (<NUM>), which is fitted at a distal end of the shaft (<NUM>) and is configured to provide images of a pericardium site in the chest;
an inflatable balloon (<NUM>), which is configured to stabilize the distal end of the shaft (<NUM>), wherein the inflatable balloon (<NUM>) is located proximally to the camera (<NUM>) so as not to obstruct the images of the target tissue site, and wherein the distal end (<NUM>) of the shaft is configured to be advanced over a guidewire (<NUM>) to bring the inflatable balloon, when collapsed, under a fatty epicardial sub-layer (<NUM>) of a pericardium site; and
an ablation catheter (<NUM>) configured to be inserted via the working vacuum channel (<NUM>) for treating the myocardium location (<NUM>), wherein the camera (<NUM>) is configured to provide images of treatment by the ablation catheter,
characterized in that the medical probe (<NUM>) comprises:
a hollow cutting tool (<NUM>) for insertion over the guidewire (<NUM>) through the working vacuum channel (<NUM>) of the shaft (<NUM>) until the hollow cutting tool (<NUM>) protrudes beyond the distal edge of the distal end (<NUM>) of the shaft (<NUM>), wherein the hollow cutting tool (<NUM>) has a form of a needle, a blade, or a cutting laser, and is configured to pierce the pericardium site, including the fatty epicardial sub-layer (<NUM>), under guidance of images taken by the camera (<NUM>), wherein the working vacuum channel (<NUM>) is configured to lift the pericardium (<NUM>) at the pericardium site to facilitate its incision by the hollow cutting tool with minimum risk to the myocardium (<NUM>) location underneath, and wherein the inflatable balloon entirely encircles a cross section, taken in a direction perpendicular to the longitudinal shaft axis, of the medical probe.