Patent Application
20140288541
1. Technical Field
The present invention relates to the field of treating flow obstructions or protrusions in vessels and/or passages in biological systems, and more particularly, to cardiovascular lesion treatment.
2. Discussion of Related Art
Atherosclerosis, which is a major cause of cardiovascular disease resulting in myocardial infarction, stroke and other major medical complications, is characterized by the progressive accumulation of atherosclerotic deposits (known as plaque) on the inner walls of arteries. Consequently, blood flow is obstructed and there is increased likelihood of clot formation that can partially or completely block or occlude an artery. Even in cases where occlusion doesn't occur, plaque is a risk factor as certain non-stable deposits, known as vulnerable plaque, may dislodge and cause a stroke or myocardial infarction. Arteries narrowed as a result of atherosclerosis that cannot be treated effectively by drug therapy are treated by medical procedures designed to restore blood flow, including highly invasive procedures such as coronary artery bypass surgery and less invasive procedures such as balloon angioplasty, atherectomy and stenting.
Bypass surgery involves opening the patient's chest and transferring a vein cut from the patient's leg to the heart to construct a detour around the occluded artery. Bypass surgery requires prolonged hospitalization and an extensive recuperation period. Furthermore, bypass surgery also exposes the patient to a risk of major surgical complications.
Balloon angioplasty is a less invasive and costly alternative to bypass surgery and is performed in a hospital cardiac catheterization laboratory by an interventional cardiologist. In this procedure, a balloon-tipped catheter is inserted into a blood vessel through a small incision in the patient's arm or leg. The physician uses a guide catheter to feed the balloon through the patient's blood vessels to the occluded artery. At that point, a guidewire is inserted across the deposits of atherosclerotic plaque, known as lesions, to provide a pathway for the balloon catheter. The deflated balloon is advanced over the guidewire, positioned within the occluded area and inflated and deflated several times. This inflation and deflation usually tears the plaque and expands the artery beyond its point of elastic recoil. Thus, although no plaque is removed the opening through which the blood flows is enlarged.
Atherectomy employs a rotating mechanical device mounted on a catheter to cut and remove plaque from a diseased artery.
Another approach to treating atherosclerosis or thrombosis is to degrade thrombi and remove plaque using various pharmacologic agents. Many techniques currently exist to deliver medicaments and other active agents to body tissues. These include oral administration, direct injection to the tissue and intravenous administration. These mechanisms are systemic in that they deliver the active agent via the bloodstream throughout the entire body. Effective pharmacologic or drug therapy requires achieving adequate concentrations of the active drug at the desired treatment site without producing drug concentrations elsewhere in the body that may cause undesirable and even dangerous side effects.
Laser angioplasty removes plaques using light in varying wavelengths ranging from ultraviolet to infrared that is delivered to the lesion by a fiber-optic catheter. Early attempts to develop a laser angioplasty system used continuous wave thermal lasers that generated heat to vaporize plaque. These laser systems caused charring and significant thermal damage to healthy tissue surrounding the lesion. As a result, thermal laser systems have generally been regarded as inappropriate for use in coronary arteries. Conversely, excimer lasers use ultraviolet light to break the molecular bonds of the atherosclerotic plaque, a process known as photoablation. Excimer lasers use electrically excited xenon and chloride gases to generate an ultraviolet laser pulse with a wavelength of 308 nm. This UV light wavelength is absorbed by the proteins and lipids that comprise plaque, resulting in precise plaque disintegration and thus, blood flow restoration without significant thermal damage to surrounding tissue. The ablated plaque is converted into carbon dioxide and other gases, as well and minute particulate matter that can be easily eliminated. Similarly, Ultrasound and RF are sometimes used for the ablation of plaque.
The challenge remains to detect and treat vascular lesions in an effective and safe manner.
Vessel manipulation is a commonly encountered challenge, especially in minimally invasive procedures. The variety of encountered vessels and the need to manipulate vessels without causing additional damage and bleeding require time and skill which may challenge procedure success and place a significant obstacle to the further development of such procedures.
Optical fibers are a common way of delivering electromagnetic radiation, e.g. laser light, to a target. Optical fibers deliver the radiation in a tight beam originating from the end face directly or projected sideways by a mirror. An optical fiber assembly generally consists of four parts: core, cladding, coating and jacket. The core is the region in which light is guided; it is usually covered by a lower index cladding, in the case of a Total Internal Reflection (TIR) fiber. In case of a Photonic Crystal Fiber (PCF), e.g. having a beehive-like structure, an OmniGuide having photonic bandgap mirrors, a Bragg fiber etc., the cladding actually consists of a complex structure of higher index of refraction materials (disclosed e.g., in U.S. Pat. No. 7,142,756 which is incorporated herein by reference in its entirety). In a metallic waveguide, the core is lower index and the cladding is a coated metal, usually Ag coated by silver-iodide AgI. In all these fiber types light is confined to the core region under normal conditions, while in extreme bends light escapes the core and can even escape the entire fiber.
It is well known that waveguides and fibers suffer losses in bends. These losses are caused by the rays' higher angle of incidence on the core/clad (mirror) interface. This is often a major limitation most manufacturers try to avoid; see for example the Corning ClearCurve Fiber (disclosed e.g., in U.S. Pat. No. 5,278,931 which is incorporated herein by reference in its entirety). Another approach is to use outside cabling, as in U.S. Pat. No. 4,078,853, which is incorporated herein by reference in its entirety, to limit fiber bending and thus loss. Other devices take advantage of the optical power loss in the construction of sensors based on the loss in bends (disclosed e.g., in U.S. Pat. No. 4,770,047 which is incorporated herein by reference in its entirety).
In another example, U.S. Pat. No. 5,138,676 which is incorporated herein by reference in its entirety, discloses tight bending with low loss that is achieved by reducing fiber outer diameter (OD) and confining light with respect to the lower-index surrounding. OD reduction is performed by either removing part of the cladding or drawing down the fiber in the bent section. Other aspects are disclosed by U.S. Pat. No. 5,278,931, U.S. Pat. No. 4,078,853, U.S. Pat. No. 4,770,047 and U.S. Pat. No. 5,138,676, which are incorporated herein by reference in their entirety.
Tissue cutting and treatment are performed in three major methods: scalpels (cold steel techniques), electro- and laser-surgery. The main use of laser surgery is in ablation or coagulation of soft tissue. In laser surgery, an optical fiber is often used to deliver the laser energy to the desired site with minimal losses on the way.
In the case of soft tissue cutting and most other medical uses of fibers, laser light is emitted from the tip of the fiber at the treatment site. The fiber is used to safely deliver the energy to the exact location in spot form as in VersaPulse by Lumenis. In some cases local redirection of the fiber tip is used for improved targeting as disclosed e.g., in U.S. Pat. No. 7,238,180, which is incorporated herein by reference in its entirety.
In other cases, the fiber is manipulated to allow laser emission at a 90° angle to the fiber tip, term “side firing”, which makes it easier to use in cases where it is geometrically harder to bend the fiber tip in the required direction. The straight angle is achieved using a mirror or a side fire mechanism. Sometimes when the side fire approach is used, specific treatment of the fiber edge is required in order to prevent local damage and facilitate effective tip side firing as disclosed e.g., in U.S. Patent Publication No. 20070106286, which is incorporated herein by reference in its entirety. In some cases tip side fire is enabled by tapering the fiber core as disclosed e.g., in U.S. Patent Publication No. 20110002584, which is incorporated herein by reference in its entirety. Alternatively, side firing is achieved by increasing the index of refraction of the cladding on one side by preferential heating, using an external laser source (disclosed e.g., in U.S. Pat. No. 6,606,431, which is incorporated herein by reference in its entirety).
The following US patents teach devices that utilize laser radiation for cutting. These patents are incorporates herein by reference in their entirety. U.S. Pat. No. 4,266,547 teaches a laser knife acting linearly between an emitter and an acceptor; U.S. Pat. No. 5,151,097 teaches a laser emitter that emits radiation through an uncovered area in an element that is otherwise covered by a light impervious material; U.S. Pat. No. 5,470,331 teaches a laser light transmissive probe system that is provided with an opposed pair of laser light transmissive probes for pinching tissue; U.S. Pat. No. 6,283,962 teaches a medical ablation device and U.S. Pat. No. 6,221,069 teaches an apparatus having an outer probe having a form of hook and an inner probe for contacting the outer probe and heating a target tissue disposed therebetween. U.S. Pat. Nos. 5,531,741 and 6,409,719, which are incorporates herein by reference in their entirety, teach devices that utilize an optical fiber to illuminate a scene in which stents are implants.
One aspect of the present invention provides a device for applying a treatment to an obstruction, comprising a flexible treatment layer that comprises a plurality of operable elements configured to be activated to apply the treatment to the obstruction upon bending of the flexible treatment layer beyond a specified curvature threshold and to be de-activated upon a specified decrease of the bending, resulting from the treatment of the obstruction.
One aspect of the present invention provides a flexible treatment layer having one or more optical fibers. The fibers comprise a core and a cladding, and have at least one specified region of the cladding that is arranged to emit electromagnetic radiation from the core upon bending the optical fiber at the at least one specified region beyond a specified bending threshold. The emission regions are operable elements of the treatment layer configured to treat the obstruction.
One aspect of the present invention provides a device such as a vessel sealing tip for surgical forceps, the vessel sealing tip comprising at least one energy delivering element arranged to deliver, upon actuation, energy to a vessel to yield a vessel welding effect in a specified sealing section of the vessel and to cut the vessel within the specified sealing section, the energy delivery being carried out via the operable elements.
These, additional, and/or other aspects and/or advantages of the present invention are set forth in the detailed description which follows; possibly inferable from the detailed description; and/or learnable by practice of the present invention.
For a better understanding of embodiments of the invention and to show how the same may be carried into effect, reference will now be made, purely by way of example, to the accompanying drawings in which like numerals designate corresponding elements or sections throughout.
In the accompanying drawings:
Prior to setting forth the detailed description, it may be helpful to set forth definitions of certain terms that will be used hereinafter.
The term “obstruction” as used herein in this application refers to any piece of matter that retards flow through a vessel. In particular, the term “obstruction” as used herein in this application includes lesions, or vascular lesions, which are deposits on arteries (e.g., plaque) as well as other distractions to normal blood flow. The terms “obstruction” and “lesion” are used interchangeably throughout the specifications, in a non-limiting manner.
The term “vessel” as used herein in this application refers to any hollow container or pipe for moving fluids. For example, the term “vessel” refers to a blood vessel, especially an artery, parts of the gastrointestinal tract, fallopian tubes, urinary or bile tracts, airways and bronchi and other bodily vessels, as well as to pipes and tubes for industrial uses. The term “vessel” is used in this application in two contexts, first in referring to vessels that enclose treated tissue such as an obstruction (e.g., a lesion in a blood vessel) and second in referring to the vessel as the treated tissue itself (e.g., welding or cutting vessels). The term “vessel” is denoted by numerals 90 or 95, depending on the context.
The terms “energy” or “treatment energy” as used herein in this application refer to any type of energy which is usable for treating or affecting vessels, for example mechanical energy, electromagnetic energy in any form (e.g., optical energy, laser energy in any effective bandwidth, radiofrequency radiation—RF etc.), electrical or magnetic energy (e.g., electric currents or magnetic fields), heat, ultrasonic radiation etc.
The terms “treatment layer” and “supporting layer” as used herein in this application refer to device elements which are involved, respectively, in energy emission and in structural support. The term “operable elements” as used herein in this application refers to any element that is associated with the treatment layer and delivers energy of any type. The term “operable elements” is further used herein in this application in a broader sense to refer to sensing and material delivery functions of the operable elements, in addition to energy delivery. The association between the operable elements and the treatment layer may be of different kinds. Non-limiting examples are mechanical structures (e.g., a surface with pores, a flexible sheet with orienting structures), radiation emitting structures (e.g., optical fibers which emit by bending), and combinations thereof (e.g., structures which direct bending and bend-emitted energy). The supporting layer may be present (e.g., a balloon, forceps jaws, a stent etc.) or be embodied into the treatment layer (e.g., balloon skin or stent surface as the treatment layer, optical fiber with emitting regions). Specifically, the terms “bend-emitting region”, “emitting region” etc. of a fiber, as used herein in this application refer to is a region of the fiber which is implemented as an operable element, according to the principles specified below.
With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.
Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is applicable to other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.
Tissue and vessel treatment devices and respective methods are provided. Devices comprise a flexible treatment layer that comprises a plurality of operable elements configured to be activated to apply the treatment to the obstruction upon bending of the flexible treatment layer beyond a specified curvature threshold and to be de-activated upon a specified decrease of the bending. The treatment layer may comprise optical fiber(s) with the operable elements as emission regions that emit electromagnetic radiation from the core upon bending the optical fiber beyond a specified bending threshold. Devices may be configured as vessel sealing tips for surgical forceps, in which the treatment layer is configured to yield vessel welding and vessel cutting effects.
The present invention enables removing and/or treating obstructions in vessels and in some cases simultaneously delivering pharmacologic therapy to a selected site in the body lumen in a simple way. The invention may treat any type of obstruction in any type of vessel, combines an automatic mechanical obstruction identification mechanism with a treatment procedure to remove and/or treat the obstruction. In an example of the obstruction being a vascular lesion, the invention may be used to remove plaque without generating embolic material which can create a risk of ischemic stroke. Furthermore, the devices described by this invention automatically identify and restrict treatment to the sclerotic area, leaving adjacent tissue unharmed.
Among other, this invention relates to methods and apparatuses for excising and/or treating mobile and non-mobile atheromas. The device includes an automated lesion identification mechanism and a treatment mechanism. In general both automated lesion detection unit and the treatment head may be inserted into the body via a catheter which may operate in different regions of the human body. For example, the aorta, common carotid artery, external and internal carotid arteries, brachiocephalic trunk, middle cerebral artery, anterior cerebral artery, posterior cerebral artery, vertebral artery, basilar artery, subclavian artery, brachial artery, axillary artery, Iliac artery, renal artery, femoral artery, popliteal artery, celiac artery, superior mesenteric artery, inferior mesenteric artery, anterior tibial artery, posterior tibial artery, the coronary arteries and all other arteries. The catheter may optionally include a blood filter means which enable to capture plaque inadvertently dislodged during an atherectomy procedure.
Device 100 comprises a flexible supporting layer 120 and a treatment layer 110 comprising a plurality of operable elements 130 attached to flexible supporting layer 120 and configured to be mechanically activated to apply the treatment to obstruction 95 upon bending of flexible supporting layer 120 due to its contact with obstruction 95. For example, operable elements 130 may be mechanically activated upon bending of flexible supporting layer 120 beyond a specified curvature threshold, as illustrated in examples below. Generally, a smaller curvature radius causes a stronger bending which activated device 100. Upon reduction if the curvature radius, de-activation may commence when the curvature radius is larger than the threshold. Hence the expression “beyond a specified curvature threshold” in the application should be interpreted as relating to a larger curvature and a smaller curvature radius.
The bending of device 100 may result from its contact with obstruction 95 or by active pressing of device 100 upon obstruction 95 to activate operable elements 130.
In embodiments, device 100 comprises a single layer having operable elements 130 such as openings going through the whole thickness of device 100. Such embodiment is illustrated in
In embodiments, operable elements 130 are further configured to be mechanically de-activated upon a specified decrease of the bending, due to the treatment of obstruction 95. For example, after the size of obstruction 95 decreases due to the treatment, the treatment may be mechanically interrupted as the curvature of device 100 decreases to a certain degree, e.g. below the specified curvature threshold or below a different threshold, determined according to the structure of the surrounding tissue.
As illustrated in
The following are some non-limiting examples for curvature thresholds with respect to various obstructions. It should be noted, as illustrated below, that generally there are two dimensions related to the curvature radius. One is in the radius of vessel 90 (in a plane perpendicular to the vessel) and the other is related to the longitudinal way along vessel 90 (in a longitudinal cross section of vessel 90). As a result, operable elements 130 (such as openings 114) may be asymmetric and have different dimensions in different directions, or be oriented in different ways along device 100 (and with respect to vessel 90). Curvature thresholds may differ in different directions, as in the longitudinal axis the reference radius (that of vessel 90 without any obstruction 95) is very large, while in the cross sectional axis the reference radius (without obstruction 95) is much smaller. Hence, different activation and de-activation thresholds may be defined for these directions and may be used to apply coarser of finer treatments, possibly simultaneously in different regions or sequentially and complementary in one region of obstruction 95.
In non-limiting examples, the following may be typical parameters for the curvature threshold in cases of different obstructions. In case of coronary lesions having a radius between 0.1 mm and 2 mm, the specified curvature threshold may be about two times the lesion radius, or up to five times the lesion radius to achieve a more thorough removal of the lesion. Device 100 may be adapted or selected according to the specific lesion that is to be treated therewith.
In case of vascular lesions having a radius between 1 mm and 10 mm, the specified curvature threshold may be about two times the lesion radius, or up to five times the lesion radius to achieve a more thorough removal of the lesion. Device 100 may be adapted or selected according to the specific lesion that is to be treated therewith.
In case of airway obstruction having a radius between 0.5 mm and 5 mm for small obstructions and having a radius between 5 mm and 20 mm for large obstructions, the specified curvature threshold may be about two times the obstruction radius, or up to five times the obstruction radius to achieve a more thorough removal of the obstruction. Device 100 may be adapted or selected according to the specific obstruction that is to be treated therewith.
In case of gastrointestinal obstructions having a radius between 10 mm and 100 mm, the specified curvature threshold may be about two times the obstruction radius, or up to five times the obstruction radius to achieve a more thorough removal of the obstruction. Device 100 may be adapted or selected according to the specific obstruction that is to be treated therewith.
In case of obstructions in water or sewage pipes, having a radius between 50 mm and 500 mm, the specified curvature threshold may be about two times the obstruction radius, or up to five times the obstruction radius to achieve a more thorough removal of the obstruction. Device 100 may be adapted or selected according to the specific obstruction that is to be treated therewith.
Device 100 may be part of an arterial catheter system which includes a flexible elongate member or catheter with an outer surface, a distal region adapted to enter an artery and a proximal region extending from a patient's vessel, permitting control outside the patient's body by a physician. At the distal region of the catheter is the atherosclerosis treating assembly which may include suction and/or drug administration surface and a balloon expansion unit. Alternatively, in some embodiments it may include an atherectomy assembly which includes a cutting blade, abrasive member, snare etc. and a trapping mechanism which in certain embodiments comprises of openings in the trapping surface which extend to the proximal region of the catheter and are attached to a vacuum source. Alternatively, in some embodiments it may include an energy source like ultrasound, laser or RF.
The physician typically determines the presence and location of the plaque using one or several visualization techniques. The distal end of the arterial catheter is inserted and deployed through an incision in the femoral or brachial artery in a manner widely used in coronary and other arteries angioplasty, atherectomy and ultrasonography catheters. The catheter's distal region is advanced within the femoral or brachial artery until the distal end reaches the region of interest. Advancement of the catheter may be facilitated by X-ray fluoroscopy and the distal region of the catheter may include one or more fluoroscopic markers to enable such visualization. Advancement may also be facilitated by IVUS, TEE or by conventional guidewire and/or guiding catheter. In some cases, a distal protection unit or other filtration means will be used, either as part of the device or as a separate tool.
Once filtration/distal-protection and general lesion identification are established, the precise lesion identification mechanism is deployed. The precise lesion identification mechanism then enables the simple delivery of treatment via drug-administration, suction and/or one of several available energy sources.
The precise obstruction identification by the bending of flexible supporting layer 120 upon contact of treatment layer 110 with obstruction 95 may be facilitated by a compliant balloon 122. Balloon 122 may be inflated such that its surface takes the shape of obstruction 95. Balloon 122 may be inflated in a manner that permits blood flow while inflated. The balloon's surface may enable the administration of treatment by mechanical, electrical, chemical or other means only at the areas made concave due to the occlusion, as illustrated in the following examples.
During the operation of device 100, lesions 95 such as plaque is reduced by suction, mechanical wear, laser, RF radiation, ultrasound or drug administration. The removal of lesion material results in a reduction of surface concavity to a level in which the bending of flexible supporting layer 120 is reduced, e.g. below the specified curvature threshold. As a result, treatment of lesion 95 may be stopped and concluded. Alternatively or additionally, the occlusion status may be monitored by sensing a status of operative elements 130 (e.g. the size of openings, the position of perforators etc. as explained below) or by detecting radio-opaque marking on device 100 the outline of a radio-opaque balloon supporting device 100. When the treatment of lesion 95 (e.g. of an occlusion) is completed, device 100 is removed, e.g. by deflation of balloon 122.
In the illustrated example, perforators 133 may be connected by supports 131 to connecting areas 132 on flexible supporting layer 120. Upon bending flexible supporting layer 120, perforators 133 may extend into lesion 95, guided by supports 131. Perforators may be hollow and extend distally to openings in flexible supporting layer 120, in drug delivery layer 125 or in suction layer 126 and function as miniature needles for drug delivery or suction. Alternatively, perforators 133 may be mounted on guides 112 for stabilization and protection in non-operative state 111A. Perforators 133 may then slide along guides 112 and extend beyond them in operative state 111B. In embodiments, guides 112 may be hollow and deliver drugs or apply suction by connection to openings in flexible supporting layer 120, in drug delivery layer 125 or in suction layer 126.
In embodiments, perforators 133 may be extended into lesion 95 by mechanical or electrical means which cause perforators 133 to penetrate the artery's inner surface to enable easy access to lesion 95. As the bending of flexible supporting layer 120 occurs only upon contact with lesion 95, all other potential administration areas remain closed and do not affected the artery's surface during the procedure. This basically serves as an “automated” procedure in the sense that it only affects the occluded areas. The holes made by perforators 133 on the surface of lesion 95 may serve as openings for drug administration, suction or mechanical mining devices designated for the treated area mainly. Referring to
Similar actuators 145 may be incorporated in other embodiments of the invention to add a control to the extent of bending experienced by device 100 and the operation of operable elements 130. For example, actuator 145 may control the extent to which openings (see below) are opened, drugs are eluted etc. Actuator 145 may be drugs 135 themselves, that may be pressurized to control the activation of operable elements 130. Actuator 145 may incorporate sensors for the bending of device 100 that may be used to monitor the treatment. In case drugs 135 are eluted in activated state 111B, drugs 135 may be stored in non-activated state 111A, e.g. within treatment layer, instead or in addition to actuator 145 as illustrated in
Actuator 145 may be part of treatment layer 110, of flexible supporting layer 120, or be implemented as an additional layer of device 100 at any location with respect to layers 120 and 110. Actuator 145 may be implemented as an elastic or a rigid wire, may be made of the same material as tubes 112 to control the extent of perforation resiliently or be associated with supports 131.
Treatment layer 110 comprises tubes 112 that are covered by caps 242 in non-active state 111A. Caps 242 may be supported by supports 241 or may be connected to the edges of tubes 112 or to supporting later 120. Upon bending flexible supporting layer 120, caps 242 move to create a gap 243 with respect to tubes 112. Gap 243 may operate as an opening for eluting drugs 135. Drugs 135 may be delivered by flexible supporting layer 120, drug delivery layer 125 or treatment layer 110, the latter e.g. via spaces 134 (
In embodiments, operable elements 130 may comprise openings 114 that are covered by corresponding discs 138, configured to expose at least one of openings 114 upon the bending of flexible supporting layer 120 beyond the specified curvature threshold. Each disc 138 may be connected to treatment layer 110 or to flexible supporting layer 120 by a holder 137, that keeps disc 138 in place while opening 114 moves behind it due to the bending of flexible supporting layer 120. Upon straightening of flexible supporting layer 120, or in areas where flexible supporting layer 120 is not bend (e.g. as device 100 is not in contact with lesion 95), discs 138 cover openings 114 and prevent drug elution or suction.
The density of openings 114 on the surface of obstruction 95 may vary according to the type of obstruction, type of treatment, type and size of openings, type of mechanical activation etc. A minimum of 5-10 openings 114 per obstruction is required. In non-limiting examples, the following may be typical parameters for the density of openings 114 of different types, in cases of different obstructions.
In case of coronary lesions having a radius between 0.1 mm and 2 mm, the distance between adjacent openings 114 may be between 0.02 mm and 0.2 mm. In case of vascular lesions having a radius between 1 mm and 10 mm, the distance between adjacent openings 114 may be between 0.2 mm and 1 mm. In case of airway obstruction having a radius between 0.5 mm and 5 mm for small obstructions and having a radius between 5 mm and 20 mm for large obstructions, the distance between adjacent openings 114 may be between 0.1 mm and 0.5 mm for small obstructions and between 1 mm and 5 mm for large obstructions. In case of gastrointestinal obstructions having a radius between 10 mm and 100 mm, the distance between adjacent openings 114 may be between 2 mm and 10 mm. In case of obstructions in water or sewage pipes, having a radius between 50 mm and 500 mm, the distance between adjacent openings 114 may be between 0.1 mm and 0.5 mm. In all these application cases, the density of openings 114 in device 100 and device 100 itself may be adapted or selected according to the specific obstruction or lesion that is to be treated therewith. Some of the applications involve continuous activation of operable elements 130 over a range of curvature radii (e.g. drug elution or suction), while other applications may involve activating the operable elements discretely (e.g. energy sources activation).
Treatment layer 110 may comprise flexible network 150 and have mesh openings 155 in network 150 as operable elements 130. Network 150 is arranged to flex upon the bending to increase an opening size in a bended area of flexible network 150. For example, network 150 may be compliant to the bending by lesion 95 and designed to widen its mesh openings 155 upon the network's compliance to the lesion's form.
In the illustrated example, mesh openings 155 in the bended regions are of a width 156 that is larger than a width 157 of mesh openings 155 in non-bended regions of network 150. For example, width 156 may be three times width 157. As illustrated in
As illustrated in
In embodiments, the space within network 150 and/or treatment layer 110 may be used to elute drugs 135 or apply suction 136 to lesion 95.
In embodiments, eluted drugs 135 may be photo activated to apply photodynamic therapy (PDT). Either or both drugs 135 and activating light may be delivered to lesion 95 via openings 114 or gap 155.
For example, a grinder 160 may be inserted into balloon 122 and rotated via handle 161. Grinder 160 may have grinding protrusions 162 that may pass through openings 114 in activated state 111B and erode obstruction 95. Protrusions 162 may either be foldable in a deactivated state or spatially removed from layer 110 in inactive state 111A.
The direction of slits 172 influences and allows spatial control of the mechanical activation of operable elements 130 (in the illustrated case openings 114, but not limited thereto). In particular, the specified curvature threshold is defined with respect to slit direction—the radius of curvature of obstruction 95 must decrease below the given threshold curvature radius along a direction that is perpendicular to slit 172 to induce the maximal opening thereof. A direction of radius of curvature decrease that is tangential to the direction of slit 172 generates much less spreading of opening 114, if at all (depending on the threshold values). Hence, the direction of slits 172 and openings 114 may be selected according to the local topography of obstruction 95 to apply the selected treatment. Any mixture of slits 172 having different orientations induces a different level of activation of operable elements with respect to a given obstruction topography, and hence allow a spatially differentiated treatment of obstruction 95, i.e. certain regions in obstruction 95 may be treated at different intensities, or a given region may be treated at different intensities sequentially by different areas of device 100.
In embodiments, the material of device 100 itself may be used to treat obstruction 95. For example, device 100 may be implemented as balloon 122 or as the parachute itself and activate the treatment upon bending of device 100 as balloon or parachute skin upon obstruction 95.
Device 100 may be configured as balloon 122 (see also
Balloon 122 may be connected to a delivery system 104 that is in fluid communication with drug delivery layer 125, suction layer 126 or flexible supporting layer 120 to elute drugs 135 or apply suction 136.
Furthermore, while vessel bifurcations are especially hard to treat with customary devices (because the prior art device must be shaped according to the bifurcation in advance), device 100 is particularly efficient is such cases as the curvature is enhanced by the bifurcation. In addition, device 100 is particularly efficient in treating the apex of the bifurcation, as the prior art disadvantage of the apex lesion having a small curvature radius become an advantage for the present invention, which utilizes the small curvature radius to enhance activation and treatment efficiency.
Fibers 110 may be wound and attached to balloon 122 in different configurations.
Winding of fibers 110 may be stent-like, having a collapsible stent-like or balloon-like configuration 122A (
In embodiments, any optical fiber may be used in combination with a stent for activating a treatment such as ablation, activation of a radiation sensitive drug or activation of nerve endings for various purposes. Regular emission from fiber tips may be used in addition to or in place of bend emission to deliver the required radiation and apply specified treatments.
Supportive structure 122 of device 100 is configured to position optical fibers 110 with respect to a target 95 (such as a flow obstruction) in a way that causes bending of all, some or at least one optical fiber 110 beyond the specified bending threshold thereof over target 95, to emit electromagnetic radiation 152 at target 95. In the case of balloon 122, inflating balloon 122 may cause fibers 110 to bend upon contacting target 95 beyond the emission threshold.
The topographically induced bending can be utilized to deliver energy specifically to those areas where the treatment is required, such as flow obstructing plaque (see e.g.,
In embodiments, fibers 110 may be arranged as resonators that amplify induced radiation from source 166 and thus generate the required radiation for treatment without using an internal light source 70.
In embodiments, parachute 123 comprises a holder 127 connected via strings 128 to device 100 and configured to guide device 100 to bend upon obstruction 95 by utilizing fluid flow patterns in the vicinity of obstruction 95. In embodiments, parachute 123 may further comprise a frontal leading area 129 configured to maintain a force resulting from fluid flow 86 and acting to position device 100 on obstruction 95. In embodiments, leading area 129 may be part of device and may be used to apply treatment. Using parachute 123 further ensures maintaining fluid flow 86 through vessel 90 during the treatment, which may be an essential requirement, e.g. when treating lesions in the carotid arteries.
In embodiments, the parachute may be replaced by a torus shaped balloon (not shown) that allows blood flow therethrough. The operation of the torus shaped balloon may similarly utilize blood flow to place device 100 upon the lesion, or generally utilize fluid flow to place device 100 upon obstruction 95.
Parachute 123 may be deployed by first releasing device 100 into the blood stream far enough from lesion 95, such that flow is not affected by lesion 95. Second, device 100 is deployed such that regions of device 100 that are in low flow or low flow resistance regions are anchored onto lesion 95 and regions of device 100 that are in high flow regions are not restricted. In this way device 100 tends to physically cover and deploy itself over the regions of lesion 95 which obstruct flow 86 the most. Parachute 123 may then be designed to include a therapeutic agent, an electric source, an ultrasound source or have light energy conducting properties to facilitate treatment by operable elements 130 at lesion 90 and prevent treatment or protect adjacent healthy regions. Furthermore, parachute 123 may be anchored to a catheter system for deployment and consequent retraction after treatment.
In embodiments, device 100 further comprises a flow sensor (not shown) for measuring the flow patterns near lesion 95. The flow measurements may be used to plan the application of parachute implemented device 100.
In embodiments, holder 127 may further comprise delivery system 139 in fluid communication with drug delivery layer 125, suction layer 126 or flexible supporting layer 120 to elute drugs 135 or apply suction 136.
In embodiments, operable elements 130 may comprise energy sources configured to deliver energy to vascular lesion 95. For example, the energy sources may deliver electromagnetic radiation to obstruction 95 such as laser energy. Operable elements 130 may comprise the energy sources themselves or optical elements that are configured to direct and deliver the electromagnetic radiation from an external energy source (not shown) to obstruction 95. In another example, the energy sources may deliver mechanical energy, e.g. in the form of ultrasound pressure waves, or electric energy, e.g. in the form of current. Operable elements 130 may comprise the energy sources themselves or transducers that receive energy from an external source (not shown).
The energy sources may be activated by the bending or may radiate at a low level that doesn't harm the surrounding. The effective energy level may be reached only upon adding several sources by the bending. Alternatively or complementary, the energy sources may be covered by treatment layer 110 and exposed to obstruction 95 upon widening of openings 114 in the cover, as described in other embodiments.
The concavity of device 100 may be used as a focusing mechanism of the energy sources. Emitted energy 152—from multiple operable elements 130 such as openings or bending regions of treatment layer 110 such as an energy delivering device, e.g., an optical fiber 110—may be concentrated due to the bending of device 100 at a focal point 96 on lesion 95. Curving treatment layer 110 over obstruction 95 points the energy sources to the same point 96 in the plaque body (in case of a vascular lesion), e.g., to the center of the plaque buildup.
Operable elements 130 may be positioned at such spaces and orientations that, upon the bending of flexible supporting layer 120 at a certain curvature, operable elements 130 deliver energy 152 to specified focal areas 96 on obstruction 95. In this way, energy 152 from different energy sources is added and may be configured to be beyond a specified treatment threshold. In such a configuration, energy 152 delivered from any single operable elements 130 (such as an opening in an energy delivering device, or bending regions of respective fiber 110) may be selected to be harmless to surrounding tissue (in state 111A), while upon concentration of several energy sources, due to the bending of device 100 on obstruction 95 (in state 111B), an effective treatment is applied. In embodiments, operable elements 130 may comprise sensors that detect the bending of obstruction 95 and activate an external energy source (not shown) to deliver energy to operable elements 130 only upon detection of obstruction 95.
It is noted that operable elements 130 as illustrated in
It is noted that bend-emission may be configured to occur inwards or outwards with respect to the direction of bending. It is further noted that the disclosed principles are also applicable to other types of waveguides, e.g., RF waveguide (see e.g.,
Bend emission may be achieved by bending fiber 110 prior to an actual application thereof, e.g. bending fiber 110 to have a snare-like form, and angled form, a stent-like form etc. (see examples below), and then controlling the bend emission by the light source upon placing the bended regions of fiber 110 in an operative position. Alternatively or complementary, bend emission may be under geometrical control, achieved by making use of the natural curvature of the targeted object to generate the desirable energy discharge profile from the waveguide. Certain regions in fiber 110 may be designed to bend-emit upon curving in contact with the target, as exemplified below, and the energy that is emitted in bends in these regions is actually used to achieve the desired goal. In such case, emission may be controlled by the actual bending, in addition or in place of controlling the light source.
Any type of fiber 110 may be arranged to emit radiation upon a specific bending, e.g. a waveguide (which may comprise metallic waveguides), a solid core optical fiber, a hollow fiber and a photonic crystal fiber (such as a holey fiber, a Bragg fiber or any other micro-structured fiber). The non-emitting sector(s) may be micro-structured (e.g. with a grating or air holes) to reduce an effective refractive index thereof below a refractive index of the emission sector and/or to direct radiation toward the emission sector.
Optical fiber 110 may be single-mode or multi-mode, in the latter case, the specified emission region and bending threshold may be selected with respect to the required modes, to control the emitted energy. In addition, the specified emission region and bending threshold may be selected with respect to, and controlled by, the beam polarization.
Bends in fiber 110 that may be used in emitting regions 130B include both micro-bends (local deviations from the fiber's linearity, with relative small bending radii) and macro-bends (changes of angle of the fiber's direction, usually larger bending radii). For example, the emitted radiation from a macro-bend may be estimated, for single mode fibers, by the expression: Exp (8.5−519·D·(λce/(2λ·MFR))3) in dB/m, where D is the bending radius in mm, λ is the wavelength in μm, λce is the fiber cut-off wavelength in μm and MFR is the mode fiber radius in μm.
Other than the prior art, the present invention utilizes conditional and controllable side emissions from an optical fiber. In contrast to side firing fibers, fibers of the present invention do not emit any radiation when straight or bended below the bending threshold. The side emission is activated only upon the bending of the fiber at a predetermined bending radius, for example by an obstruction that is to be removed by the fiber, or according to a specific device design.
During treatment by emitted radiation 152, parts of the treated target (e.g. a flow obstruction or a polyp) are removed, causing the target to be decimated and flattened. In some embodiments, target flattening reduced the bending of fiber 110 (increases the bending radius thereof) and causes a reduction in bend emission until conclusion of the treatment. Such effect may be desired and taken into account when selecting the bending threshold. In some embodiments, a different specified region may take over the treatment, and be activated by a different bending threshold to allow multi-stage treatment.
In one example, the specified region has a cladding 115A having a refractive index nM in a non-emitting sector 130A and a cladding 115B having a refractive index nE in an emission sector 130B. In case of a solid core fiber, the refractive indices satisfy nK≧nE>nM. In case of a hollow (air) core fiber, the refractive indices satisfy nM,nE>nK. In the latter case, embodiments may comprise either nM≧nE or nE≧nM depending on the indices of refraction and on the material's absorption, scattering and micro-structure.
In embodiments, one or more optical fibers 110 may be incorporated in a device 100 (see e.g.
In embodiments, the normalized refractive index difference between the cladding of the specified emission region and the cladding of non-emitting regions may be larger than ca. 0.1% (e.g. as Δ=(nE−nM)/nE), and may be larger than ca. 0.5%. Differences may be larger or smaller, depending on the exact materials and structures used and operational (predefined or resulting) bending radii 105 (as a non-limiting rule of thumb, the larger the difference in refractive indices, the smaller is the threshold bending radius).
Two non-limiting examples, which refer to commercial SiO2 fibers having a refractive index of nK=1.457 (at 633 nm) are (i) nM=1.456 and nE=1.457 and (ii) nM=1.000 and nE=1.450.
Electromagnetic radiation, such as laser energy, may be delivered to either or both cores 103B, 103A simultaneously or sequentially. Without loss of generality, fiber 110 may have several specified regions and/or several emission sectors 130B, 130C etc. which may be constructed axially so as to deliver energy along fiber 110 to different specified regions and/or the emission sectors may be constructed tangentially to deliver energy to several regions along fiber 110 simultaneously or sequentially.
The serrations on the concave side can guide the energy in a periodic manner (see
The fiber's cross section may be configured to emit radiation 152 not only in a specific direction but also in a specific profile. The light from core 103 may be optically manipulated to exit the waveguide in a narrow flat profile or alternatively in a dispersive profile as needed. Core-cladding interface 153 may be designed to serve as a lens to focus the naturally dispersive energy. For example,
The index of refraction also depends on temperature. Generally, an increase of temperature causes an increase in the index of refraction. In one embodiment, in which fiber 110 is inherently asymmetric as in
For construction purposes, fiber 110 may be attached to or embedded in reinforcing structure or stabilizer 141, to ensure stability and prevent breakage. Reinforcing structure 141 may be a semi-tube (e.g., similar to coating 140 in
Embodiments of the invention further comprise optical fibers with an asymmetric cross section, and in particular optical fibers with asymmetric cladding, in which the asymmetry defines at least one emission sector and at least one non-emitting sector in cross section. The difference in the refractive indices between the emitting and non-emitting sectors may be larger than 0.1%, larger than 0.5% or larger than the difference in the refractive indices between the emitting sector and the fiber's core.
The following illustrations depict examples for devices 100 which implement optical fibers 110 exhibiting bend-emission. Each device 100 may be implemented using any embodiment of optical fiber 110 described above according to the device's specifications, under constraints resulting from manufacturing issues but not from conceptual issues.
Device 100 comprises at least one optical fiber 110 and at least one light source 70 (see e.g.,
For example, optical fiber 110 may be formed as a snare (
In embodiments, optical fiber 110 of the snare may have an additional emitting region 130C, e.g. defined by a sector 115C of the cladding at an angle to main emitting sector 115B of the cladding. Region 130C may emit electromagnetic radiation 151 having different characteristics than electromagnetic radiation 152 used for cutting, for example, weaker radiation or radiation in a different wavelength range, that may be useful e.g. for ablating the edges of obstruction 95 to prevent bleeding and prevent infection. It is noted that such ablation is more effective than prior art laser ablation, as radiation 151 is applied smoothly and in the correct direction due to the structure of the snare itself (see
A further advantage of fiber snare 110 with respect to a prior art electrosurgical snare is illustrated in experimental results depicted in
In embodiments of device 100, light source 70 may comprise at least two light sources 70 configured to transmit at least one treatment beam and at least one guiding beam through at least one optical fiber 110. For example, a guiding beam may be used to mark the treatment plane of fiber snare 110 or fiber hook 110 without affecting obstruction 95. Such a guiding beam may be very useful for surgical planning and may further enhance the accuracy of operation using device 100.
In an embodiment illustrated in
In embodiments illustrated in
Normally, fiber materials like silica tend to have lower values of tensile stress than compressive stress. Basically this means that when bending a symmetrical fiber the breaking point is typically determined by reaching the tensile stress limit. In one embodiment, the effective tensile stress limit is geometrically increased using hollow structures such as tubes. Fiber 110 may be constructed as a hollow tube (
In embodiments, cladding 115 may be arranged to become asymmetric in cross section upon application of strain 174 at the specified region. The asymmetry may be expressed in a form of cladding 115, a thickness of cladding 115 and/or in the refractive index of cladding 115. The asymmetry may be configured to focus emitted electromagnetic radiation 152.
In embodiments, photoelasticity may be used to change the index of refraction under stress, in order to fine-tune the ability of the waveguide (e.g., fiber 110) to discharge energy asymmetrically. The index of refraction of most materials depends on stress. Typically in glass, when stress is increased the index of refraction increases as well. Photoelasticity is caused by the deformation of the electron shells of atoms and molecules and by the orientation of optically anisotropic molecules or components of such molecules; in polymers, it is caused by the uncoiling and orientation of polymer chains. For a small uniaxial tension or compression, Brewster's law is satisfied, such that the optical path equals the index of refraction times the geometrical, or the stress index multiplied by the stress and the geometrical path.
When a waveguide like an optical fiber is bent, a symmetry break occurs in the stress distribution in the fiber's cross-section. Inner side 175A is compressed and outer side 175B expands, resulting in an increase in tensile stress. Solving the Euler-Bernoulli beam equation implies that pure (convex) bending causes zero stress at the neutral axis (
The bend causes a symmetry break between cladding 115 on the inside of the bend, the radiation emitting section, and cladding 115 on the outside of the bend. Typically, the cladding's refraction index is lower than that of core 103 by about 0.5%. A bend in the fiber effectively closes the index gap in compressed side 175A and on the other hand increases the gap on outer side 175B. This makes the light confinement weaker on the inner side making it leakier.
The asymmetry due to the bend guides the discharge 152. By bending the waveguide and the subsequent increase in the index of refraction specifically at inner side of the bend 175A, the direction of the discharge 152 is controlled. The index differential at the boundary between core 103 and cladding 115 is tailored in accordance with the desired bend that causes discharge 152.
The cross-section of fiber 110 may be designed to control the stress profile.
In addition to providing an emission profile, devices 100 and fibers 110 may be designed to correlate the forces applied thereupon to the intensity of radiation 152, as larger forces produce stronger bending of fibers 110, resulting in more intense radiation. Such designs may enhance the feel provided by device 100 and make the feel more similar to cutting with a regular scalpel mechanically.
Tweezers device 100 hence allows mechanical handling while using laser for cutting tissue. The emission may be dependent on the extent of the force applied by the physician through the extent of resulting bending of fiber(s) 110. The closer arms 310, 311 are pressed together, the larger becomes the fiber bending and the emitted radiation.
In embodiments, fiber 110 may reach tip 321A of arm 322 and be used additionally as a tip-emitting fiber (“straight shot laser”).
The illustrated tweezers with arms 310 and 311, 320 and 322, 340 and 345 may be embodiments of supportive structure 141 described above.
Embodiments of the invention provide device 100 as a vessel sealing tip 100 for surgical forceps which allows, via operable elements 130 implemented e.g., in fiber 110, both sealing a vessel section and cutting therethrough without extracting the tip out of the body or exchanging the tip. Either a single action yields the sealing and the cutting, or two or more tip actions may be carried out sequentially to perform the sealing and cutting operations. In addition, the tip may be used for cutting through tissue. Embodiments of the tip may utilize any energy source via operable elements 130, in particular optical laser energy but also RF or ultrasound energy. The different effects (sealing, cutting) may be achieved by varying the emitted energy spatially, by manipulating the vessel prior or during energy delivery, by changing a configuration of the tip during operation and by combining tensile forces or ablation at appropriate locations of the vessel.
Vessel sealing tip 100 may comprise an energy delivery element 110 such as at least one optical element 110 arranged to deliver, upon actuation, electromagnetic radiation 152 to a vessel 90 to cut vessel 90 at a cutting region 96B (
Energy delivery element 110 may be attached to any one of two jaws 101 (101A, 101B) of forceps tip 100, or may also be a free element, at least on a part of the length thereof (see below).
In cases of energy delivery element 110 being an optical fiber, fiber 110 may emit radiation 152 (
Fiber cross section may be designed according to the principles outlined in
In certain embodiments, at least one jaw 101 of the forceps may comprise at least one protrusion 94A (
Certain embodiments of the invention comprise a tip 100 with at least two jaws 101 for surgical forceps 92. At least one of jaws 101 may comprise at least one protrusion 94A positioned to contact tissue held by tip 100 and deliver both pressure and external energy to the tissue. The pressure may be a tip holding force (the force applied to the forceps and thereby transferred to the tip's jaws), concentrated by at least one protrusion 94A. The external energy may be any of electromagnetic (e.g., optical, RF), electrical and ultrasound energy, or a combination thereof. At least one protrusion 94A may comprise one or more thin element that concentrates applied forces onto a small section of vessel 90. At least one protrusion 94A may comprise an abrasive or an ablative element that reduces vessel wall thickness or even cuts the vessel, in addition to constricting the vessel.
In certain embodiments, energy delivery element 110 may be arranged to reduce a vessel wall thickness prior to the welding. For example, optical element 110 may operate in an ablative mode to reduce vessel wall thickness prior of holding vessel 90 sealing it and cutting through vessel 90. The reduction of wall thickness allows energy to be delivered to the internal walls of vessel 90 without causing thermal damage to the external wall of vessel 90. Furthermore, reducing the wall thickness may reduce the wall resistance to mechanical pressure and thus allow a more effective application of pressure to vessel 90, e.g., by protrusions 94A (
In certain embodiments, vessel sealing tip 100 for surgical forceps 92 may comprise at least one transversely expandable element 102 or 303 arranged to yield a specified extension of a specified section of vessel 90 and energy delivery element 110 arranged to deliver external energy, upon actuation, to vessel 90 to yield a vessel welding effect in a specified sealing section of vessel 90 and to cut vessel 90 within the specified sealing section. The external energy may be at least one of optical, electrical and ultrasound energy. Tip 100 may thus open up and create a seal larger than half width of tool (e.g., tip 100) or just separate regions of cut and seal. The specified sealing section may be mechanically extended during the welding with or without additional energy delivery. In embodiments, tip 100 may comprise two transversely expandable elements 103, each arranged to yield a specified extension of the specified section of vessel 90 in a different plane.
In certain embodiments, vessel sealing tip 100 may be constructed from non-metallic materials to allow use of tip 100 simultaneously with MRI imaging. For example, tip 100 may be made of plastic and energy may be delivered via optical fibers.
In certain embodiments, vessel sealing tip 100 may comprise at least one wave guide (not shown) arranged to deliver, upon actuation, electromagnetic radiation to the vessel to yield a vessel welding effect in a specified sealing section of the vessel and to cut the vessel within the specified sealing section. In certain embodiments, at least one jaw of the forceps may comprise at least one protrusion arranged to constrict the vessel prior to the actuation of the at least one wave guide.
In certain embodiments, vessel sealing tip 100 for surgical forceps 92 may be configured to be applied for any of the following treatments: Sealing blood vessels, arteries, veins; Sealing biliary ducts; Sealing urinary tract; Sealing reproductive tract; Sealing airways; Sealing in the GI tract; Sealing the dura; Treating septums (nasal, atrial, etc.); Sealing organs such as lung, liver, spleen, heart, stomach, pancreas, uterus, bladder, kidney etc. While the above description mainly referred to treating vessels 90, tip 100 for surgical forceps 92 may be configured for treating any other type of tissue, as well as to carry out further surgical tasks, such as cutting or ablating tissue.
In a non-limiting example, vessel sealing tip 100 may be configured to apply pressures in the at least a part of the range 20-400 PSI. The outer diameter of fiber(s) 110 may be between 0.05-2 mm and fiber(s) 110 may be arranged to deliver power levels between e.g. 1 W-100 W. Tip 100 may be configured to have a jaw 101 length between 2-50 mm, a jaw 101 width between 0.5-10 mm, and a ridge width of at least one protrusion 95A between 0.1-5 mm. The dimensions of jaws 101 may be configured with respect to the specific use of tip 100, as illustrated in the examples above. For example, larger tips 100 may be designed to seal larger or stiffer vessels 90.
Table 1 is a non-limiting exemplary overview of possible tip characteristics for various applications of tip 100.
Method 400 may comprise designing a device for applying a treatment to an obstruction (stage 410) comprises the following stages: attaching a treatment layer comprising a plurality of operable elements to a flexible supporting layer (stage 438); designing (stage 440) the operable elements to be mechanically activated (stage 442) upon bending of the flexible supporting layer beyond a specified curvature threshold (stage 444) due to contact of the treatment layer with the obstruction (such as a vascular lesion) (stage 446); and configuring the operable elements (stage 460) to apply the treatment (stage 462) to the obstruction upon their mechanical activation.
Method 400 may further comprise designing the operable elements to be mechanically de-activated upon a specified decrease of the bending (stage 443), due to the treatment of the obstruction.
Method 400 may further comprise designing the operable elements to comprise openings (stage 412) and configuring the openings to be opened mechanically by the mechanical activation (stage 448).
Method 400 may further comprise selecting an orientation of the operable elements with respect to a form of the obstruction (stage 449) for example to apply a spatially differentiated treatment. Curvature thresholds may be selected according to the orientation of the operable elements or vice versa. Curvature thresholds may vary for different orientations on obstruction 95.
Method 400 may further comprise covering the openings by corresponding discs (stage 414), and configuring the discs to expose the openings upon the mechanical activation (stage 450).
Method 400 may further comprise configuring the treatment layer as a flexible network in which mesh openings widen upon the bending (stage 415). The treatment may be applied utilizing the wider mesh openings to treat the lesion specifically.
Method 400 may further comprise designing the operable elements to comprise perforators (stage 416), and configuring the perforators to penetrate the obstruction (e.g. a vascular lesion) upon the mechanical activation (stage 452).
Method 400 may further comprise operably associating a drug delivery system with the operable elements (stage 470) and eluting drugs to the lesion thereby (stage 472). Method 400 may further comprise delivering light sensitive drugs and/or light through the openings, to enable photodynamic therapy (stage 473).
Method 400 may further comprise operably associating a suction system with the operable elements (stage 474) and removing fluids by suction from the lesion thereby (stage 476).
Method 400 may further comprise designing the operable elements to comprise energy sources (418), and positioning the energy sources (stage 478) to be directed (480) at the obstruction upon the bending of the flexible supporting layer beyond the specified curvature threshold (444).
Method 400 may further comprise attaching a balloon to the flexible supporting layer (stage 486) to enable the bending (stage 444) by inflating the balloon (stage 292).
Method 400 may further comprise attaching a parachute to the flexible supporting layer (stage 496) to enable the bending (stage 444) by drifting the parachute with flow (e.g. blood flow) until being obstructed by the vascular lesion (stage 497).
In embodiments, method 400 comprises treating an obstruction (stage 405) by mechanically activating operable elements of a bendable device (stage 442) by bending the device onto the obstruction (stage 444).
For example, treating a vascular lesion (stage 405) comprises eluting drugs into the lesion (stage 472) through openings, exposed (stage 448) or perforated (stage 452) by the operable elements. In another example, treating the vascular lesion (stage 205) comprises removing fluids by suction from the lesion (stage 476) through openings, exposed (stage 448) or perforated (stage 452) by the operable elements.
In embodiments, treating the vascular lesion (stage 405) comprises directing the energy sources at the vascular lesion upon the bending of the flexible supporting layer beyond the specified curvature threshold (stage 480).
Contacting the vascular lesion may be carried out by inflating a balloon attached (stage 486) to the flexible supporting layer or by drifting a parachute attached to the flexible supporting layer (stage 296) with blood flow until being obstructed by the vascular lesion, to enable the bending (stage 297).
Method 400 may further comprise configuring emission from an optical fiber (stage 421) and removing an obstruction therewith (stage 432), according to some embodiments of the invention.
Method 400 comprises arranging at least one specified region in the optical fiber to emit transferred electromagnetic radiation from a core through a cladding of the optical fiber upon bending of the optical fiber at the at least one specified region beyond a specified bending threshold (stage 482).
Method 400 may further comprise configuring the cladding to be asymmetric in cross section at the at least one specified region (stage 422) and to comprise at least one emission sector and at least one non-emitting sector. Method 400 may further comprise setting an effective refractive index nE of the at least one emission sector closer to a core refractive index nK than a cladding refractive index nM (stage 423), to yield transmission through the at least one emission sector upon bending of the optical fiber at the at least one specified region beyond a specified bending threshold.
Setting the effective refractive index nE (stage 423) may be carried out by at least one of: changing nM to nE (stage 424); serrating the cladding (stage 425); micro-structuring the cladding (stage 426); optionally positioning the core asymmetrically or eccentrically within the cladding (stage 427); applying an asymmetric coating onto the cladding (stage 428); and straining the fiber (stage 429), e.g., mechanically, thermally, or using radiation (e.g. ultraviolet light).
Method 400 may comprise configuring the at least one specified region to emit the electromagnetic radiation in a plane defined by the fiber (stage 484) and removing the obstruction (stage 432) by crossing the obstruction by the plane (stage 485).
Method 400 may further comprise attaching at least one optical fiber with the at least one specified region to a supportive structure (stage 487) and configuring the supportive structure to position the at least one optical fiber with respect to a target in a way that causes bending of the at least one optical fiber beyond the specified bending threshold thereof over the target (stage 488), to emit the electromagnetic radiation at the target (stage 495).
Removing the obstruction (stage 432) may be carried out by applying to the obstruction at least one specified region of at least one optical fiber arranged to emit transferred electromagnetic radiation from a core through a cladding of the optical fiber upon bending of the optical fiber at the at least one specified region beyond a specified bending threshold (stage 430).
The at least one optical fiber may be applied to the obstruction (stage 430) by inflating a balloon (stage 494) to which the at least one optical fiber is attached (stage 493) against the obstruction to yield bending of the at least one optical fiber at the at least one specified region beyond a specified bending threshold.
In embodiments, device 100 and method 400 are used to assist in medical procedures, specifically by soft tissue cutting utilizing fiber-optic bends for laser energy discharge. The natural curvature in clinical settings is used to induce safe, controlled and predetermined laser discharge from the fiber's side for various purposes like soft tissue, cartilage and bone cutting, ablation and coagulation. Furthermore the controlled discharge may be used for other purposes without limitation such as sensing, material processing and other applications.
Device 100 and method 400 may be used for cutting and/or removing polyps, lesions, soft tissue sarcomas, benign and malignant tumors and other soft tissue applications. In another embodiment it is used for moderate tissue damage treatments like atrial fibrillation, denervation or nerve inhibition and/or excitation and drug activation through photodynamic therapy. Device 100 and method 400 may be used to provide means of transporting of light energy to the desired location, adjusted to the specific geometry and emission of energy to the tissue to allow safe ablation/coagulation/cutting of the tissue in a precise and controlled manner. Device 100 and method 400 may be used in different parts of the animal or human body, such as: the colon, ileum, cecum, esophagus, stomach and all other parts of the digestive system; the urethra, urinary bladder, ureter, kidney or any other part of the urinary system also the vagina, cervix, uterus, ovaries, prostate gland, penis and all other parts of the reproductive system; the nasal and oral cavities, the epiglottis, trachea, bronchus, lungs and all other parts of the respiratory system; the brain, spinal cord and all other parts of the nervous system; as well as all parts of the circulatory system, veins, arteries the heart etc. It may also operate on parts of the skin or dermatology related procedures, plastic and general surgery procedures.
In embodiments, device 100 and method 400 may be used to treat atherosclerosis by laser atherectomy by delivering the laser energy specifically to the calcified lesion by using its topography to induce the tight bends in the fiber, which in turn causes the beam to “leak” out of the fiber and be transmitted to the lesion. Thus, device 100 and method 400 take advantage of the geometry of the lesion to target the discharge exclusively at the treatment site.
The following are some non-limiting examples for bending thresholds with respect to various obstructions. It should be noted, as illustrated below, that generally there are two dimensions related to the bending, or curvature radius. One is in the radius of vessel 90 (in a plane perpendicular to the vessel) and the other is related to the longitudinal way along vessel 90 (in a longitudinal cross section of vessel 90). As a result, fiber 110 may be asymmetric and have different dimensions in different directions, or be oriented in different ways along device 100 (and with respect to vessel 90). Bending or curvature thresholds may differ in different directions, as in the longitudinal axis the reference radius (that of vessel 90 without any obstruction 95) is very large, while in the cross sectional axis the reference radius (without obstruction 95) is much smaller. Hence, different emission parameters may be defined for these directions and may be used to apply coarser of finer treatments, possibly simultaneously in different regions or sequentially and complementary in one region of obstruction 95.
In non-limiting examples, the following may be typical parameters for the bending threshold in cases of different obstructions. In case of coronary lesions having a radius between 0.1 mm and 2 mm, the specified bending threshold may be about two times the lesion radius, or up to five times the lesion radius to achieve a more thorough removal of the lesion. Fiber 110 and device 100 may be adapted or selected according to the specific lesion that is to be treated therewith.
In case of vascular lesions having a radius between 1 mm and 10 mm, the specified bending threshold may be about two times the lesion radius, or up to five times the lesion radius to achieve a more thorough removal of the lesion. Fiber 110 and device 100 may be adapted or selected according to the specific lesion that is to be treated therewith.
In case of airway obstruction having a radius between 0.5 mm and 5 mm for small obstructions and having a radius between 5 mm and 20 mm for large obstructions, the specified bending threshold may be about two times the obstruction radius, or up to five times the obstruction radius to achieve a more thorough removal of the obstruction. Fiber 110 and device 100 may be adapted or selected according to the specific obstruction that is to be treated therewith.
In case of gastrointestinal obstructions having a radius between 10 mm and 100 mm, the specified bending threshold may be about two times the obstruction radius, or up to five times the obstruction radius to achieve a more thorough removal of the obstruction. Fiber 110 and device 100 may be adapted or selected according to the specific obstruction that is to be treated therewith.
In case of obstructions in water or sewage pipes, having a radius between 50 mm and 500 mm, the specified bending threshold may be about two times the obstruction radius, or up to five times the obstruction radius to achieve a more thorough removal of the obstruction. Fiber 110 and device 100 may be adapted or selected according to the specific obstruction that is to be treated therewith.
Device 100 may be part of an arterial catheter system which includes a flexible elongate member or catheter with an outer surface, a distal region adapted to enter an artery and a proximal region extending from a patient's vessel, permitting control outside the patient's body by a physician. At the distal region of the catheter is the atherosclerosis treating assembly which may include suction and/or drug administration surface and a balloon expansion unit.
Method 400 may further comprise vessel sealing by delivering, upon actuation, energy to a vessel (stage 510) to yield a vessel welding effect in a specified sealing section of the vessel and to cut the vessel within the specified sealing section. Method 400 may comprise welding the vessel in a specified sealing section (stage 512) and cutting the vessel within the specified sealing section (stage 514). In certain embodiments, the welding and the cutting may be carried out by a single actuation. The delivered energy may comprise at least one of optical, electrical and ultrasound energy
For example, the delivered energy may be electromagnetic radiation and method 400 may further comprise creating the welding and cutting by differently focusing the delivered electromagnetic radiation on the specified sealing section and on the cutting location, respectively, to differentiate sealing and cutting (stage 520).
In another example, the delivered energy may be electromagnetic radiation method 400 may further comprise using at least one optical fiber arranged to emit the electromagnetic radiation at at least two radiation profiles, one corresponding to welding 512 and another corresponding to cutting 514 the vessel. Generally, certain embodiments may comprise delivering electromagnetic energy at different profiles to differentiate sealing and cutting (stage 522). For example, radiation energy profiles may be differentiated along a delivery fiber (stage 524), across a delivery fiber (stage 526) or by a combination thereof and in respect to the positioning of the delivery fibers in jaws of a forceps tip arranged to perform method 400.
In certain embodiments, method 400 may further comprise constricting the vessel prior to the actuation (stage 516). The constriction may be arranged to yield more effective sealing and/or cutting by reducing the vessel diameter and increasing the usable spatial variability of energy delivery.
In certain embodiments, method 400 may further comprise penetrating a lumen of the vessel prior to the actuation (stage 518). Penetrating the vessel enables sealing the vessel from within and thereby applying the delivered energy efficiently and in a controllable manner to seal and cut the vessel.
In certain embodiments, method 400 may further comprise mechanically extending the specified sealing section (stage 530). The extending may be carried out prior, during or after sealing the vessel to broaden the sealing section to allow more effective cutting and healing of the cutting location.
In the above description, an embodiment is an example or implementation of the invention. The various appearances of “one embodiment”, “an embodiment”, “certain embodiments” or “some embodiments” do not necessarily all refer to the same embodiments.
Although various features of the invention may be described in the context of a single embodiment, the features may also be provided separately or in any suitable combination. Conversely, although the invention may be described herein in the context of separate embodiments for clarity, the invention may also be implemented in a single embodiment.
Certain embodiments of the invention may include features from different embodiments disclosed above, and certain embodiments may incorporate elements from other embodiments disclosed above. The disclosure of elements of the invention in the context of a specific embodiment is not to be taken as limiting their used in the specific embodiment alone.
Furthermore, it is to be understood that the invention can be carried out or practiced in various ways and that the invention can be implemented in certain embodiments other than the ones outlined in the description above.
The invention is not limited to those diagrams or to the corresponding descriptions. For example, flow need not move through each illustrated box or state, or in exactly the same order as illustrated and described.
Meanings of technical and scientific terms used herein are to be commonly understood as by one of ordinary skill in the art to which the invention belongs, unless otherwise defined.
While the invention has been described with respect to a limited number of embodiments, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of some of the preferred embodiments. Other possible variations, modifications, and applications are also within the scope of the invention. Accordingly, the scope of the invention should not be limited by what has thus far been described, but by the appended claims and their legal equivalents.
This application is a continuation-in-part of International Patent Application No. PCT/IL2012/050496, filed on Dec. 4, 2012, which claims the benefit of U.S. Provisional Patent Application No. 61/566,667, filed Dec. 4, 2011. This application also claims priority as a continuation-in-part to International Patent Application No. PCT/IL2013/050099, filed on Jan. 31, 2013, which claims priority from U.S. Provisional Patent Application No. 61/592,602, filed Jan. 31, 2012. This application also claims the benefit of U.S. Provisional Patent Application No. 61/847,090, filed Jul. 17, 2013. Each such noted application is herein incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61566667 | Dec 2011 | US | |
| 61592602 | Jan 2012 | US | |
| 61847090 | Jul 2013 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/IL2012/050496 | Dec 2012 | US |
| Child | 14293058 | US | |
| Parent | PCT/IL2013/050099 | Jan 2013 | US |
| Child | PCT/IL2012/050496 | US |
