CROSS-REFERENCE TO RELATED APPLICATIONThis application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 60/851,141 filed Oct. 11, 2006. This provisional application is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention relates generally to a light delivery system useable for medical treatment, such as light therapy for the treatment of proliferative diseases.
2. Description of the Related Art
Light therapy includes photodynamic therapy (PDT) which is a process whereby light of a specific wavelength or waveband is directed toward a target cell or cells that have been rendered photosensitive through the administration of a photo-reactive, photo-initiating, or photosensitizing agent. This photo-reactive agent has a characteristic light absorption waveband and is commonly administered to a patient via intravenous injection, oral administration, or by local delivery to the treatment site. It is known that abnormal cells in the body may selectively absorb certain photo-reactive agents to a greater extent than normal for healthy cells. Once the abnormal cells have absorbed and/or molecularly joined with the photo-reactive agent, the abnormal cells can then be treated by exposing those cells to light of an appropriate wavelength or waveband that substantially corresponds to the absorption wavelength or waveband of the photo-reactive agent.
The objective of PDT may be either diagnostic or therapeutic. In diagnostic applications, the wavelength of light is selected to cause the photo-reactive agent to fluoresce as a means to acquire information about the targeted cells without damaging the targeted cells. In therapeutic applications, the wavelength of light delivered to the targeted cells treated with the photo-reactive agent causes the agent to undergo a photochemical reaction with oxygen in the localized targeted cells, to yield free radical species (such as singlet oxygen), which cause localized cell lysis or necrosis.
PDT has therefore proven to be an effective oncology treatment for destroying targeted cancerous cells. In addition, PDT has been proposed as a treatment for other ailments, some of which are described in Applicant's co-pending patent application U.S. Publication No. 2005/0228260 (U.S. patent application Ser. No. 10/799,357, which is hereinafter referred to as the '357 patent application).
One type of light delivery system used for PDT treatments comprises the delivery of light from a light source, such as a laser, to the targeted cells using a single optical fiber delivery system with special light-diffusing tips. This type of light delivery system may further include single optical fiber cylindrical diffusers, spherical diffusers, micro-lensing systems, an over-the-wire cylindrical diffusing multi-optical fiber catheter, and a light-diffusing optical fiber guidewire. This light delivery system generally employs a remotely disposed high-powered laser or solid state laser diode array, coupled to optical fibers for delivery of the light to the targeted cells. However, the use of laser light sources has several drawbacks, such as relatively high capital costs, relatively large size equipment, complex operating procedures, and safety issues in working with and around high-powered lasers.
The '357 patent application addresses some of these concerns and also addresses the desire to develop a light-generating apparatus that can be secured within a blood vessel or other orifice. The securing mechanism of such an apparatus would also be capable of removing light absorbent or light blocking materials, such as blood, tissue, or another object from the light path between the targeted cells and the light transmitters. Securing the apparatus within a blood vessel, for example, can be achieved with an inflatable balloon catheter that matches the diameter of the blood vessel when the balloon is inflated.
An introducing sheath having a lumen extending therethrough to create a passageway for insertion of other instruments into a patient's body through the sheath may be used with the light delivery system. One type of introducing sheath is described in another one of Applicant's co-pending patent applications, PCT Application No. PCT/US2005/032851. In general, this type of introducing sheath surrounds a penetrating device, which is introduced into the body and then removed, leaving the sheath behind as a passageway. One such instrument that can be inserted through the sheath is a light catheter for PDT treatment.
The light source for the light system used for PDT treatments may also be light emitting diodes (LEDs). Arranged LEDs form a light bar for the light system, where the LEDs may be either wire bonded or electrically coupled utilizing a “flip chip” technique that is used in arranging other types of semiconductor chips on a conductive substrate. Various arrangements and configurations of LEDs are described in U.S. Pat. Nos. 6,958,498; 6,784,460; and 6,445,011; and also in the '357 patent application.
BRIEF SUMMARY OF THE INVENTIONThe embodiments described herein are generally related to a light delivery system usable for treating a patient by light therapy. As used herein, the term “light therapy” is to be construed broadly to include, without limitation, methods of treating a patient with light applied externally and/or internally. Light therapy can be used to treat various types of medical conditions, such as proliferative diseases including cancer. The light delivery system can have a relatively simple construction to reduce production time and fabrication costs. In some embodiments, the light delivery system comprises a catheter having a light bar, which is formed by a series of light sources positioned along a mounting base. The light bar is capable of delivering a sufficient amount of light to effectively treat target tissue. In one embodiment, the light bar is positioned within a distal tip of the catheter.
The distal tip is preferably flexible such that the distal tip can be twisted, bent, rolled or otherwise distorted. Thus, the distal tip can assume various positions during treatment without adversely affecting performance of the catheter or traumatizing the patient. In other embodiments, the distal tip is semi-rigid or rigid and is particularly well suited for delivery along somewhat linear delivery paths. The semi rigid or rigid distal tip can maintain its shape throughout the entire delivery process.
In some embodiments, a light delivery system for treating a patient includes a catheter having one or more light sources capable of transmitting light. The light sources can be energized in situ so as to output radiative energy. In some embodiments, the light sources are LEDs that form a light bar. The LEDs can be linearly spaced along a distal end of the catheter. In some variations, the LEDs are mounted to a mounting member which is sufficiently flexible to bend through an angle of at least 180°, 160°, 140°, 100°, 90°, 80°, or ranges encompassing such angles. In some variations, the mounting member is substantially optically transparent for transmitting light emitted by the LEDs.
In some embodiments, the light delivery system is a low profile catheter that is used to treat remote target region(s) of a patient. The catheter is sufficiently flexible so as to permit delivery along a tortuous path through the patient in order to locate a distal end of the catheter at the desired remote target region.
In some embodiments, a device for performing a medical treatment comprises a plurality of light sources capable of emitting light for treating a patient and a distal tip. The distal tip has an elongate base and is dimensioned for placement within a patient. The base can comprise a transmissive material. In some embodiments, the device can be flexible, semi rigid, and/or rigid.
In other embodiments, a device for performing a medical treatment is provided. The device comprises a plurality of light sources capable of emitting light for treating a patient; and a distal tip has an elongate base and is sufficiently flexible for placement within a patient, the base comprises a transmissive material such that a substantial portion of the light emitted from the plurality of light sources directed towards the base is transmitted through the base when the light sources are energized, the plurality of light sources being mounted upon the base.
In some embodiments, a method of producing a catheter for treating a patient is provided. The method comprises coupling a plurality of light sources onto a transparent elongate support, the light sources being spaced from one another; connecting the plurality of light sources such that a power source energizes the plurality of light sources; and placing an outer body around the elongate support and plurality of light sources mounted thereto, the outer body configured for positioning with a patient at a selected treatment location.
In some embodiments, a method of forming a light delivery system for treating a patient is provided. The method comprises placing an array of light energy sources in an array of holders of a fixture device, the light energy sources configured to treat a patient when energized in situ; electrically coupling the light energy sources together while the light energy sources are retained in the holders; after coupling the light energy sources together, removing the light energy sources from the fixture device; and encapsulating the array of light energy sources within an outer body, the outer body dimensioned for placement within a patient.
The light delivery systems described herein are well suited for other uses. For example, the light delivery systems can be used to improve lighting conditions during manufacturing processes, installation processes, repair processes, and the like. In some embodiments, the light delivery system can be used in combination with a viewing system (e.g., a camera, optical fibers, etc.). During operation of the viewing system, the light delivery system can provide adequate illumination for proper viewing. As such, the light delivery system can be used in the aerospace industry, electronics industry, construction, and other industries or settings that may require viewing in relatively small and/or remote locations having limited access, for example.
The light delivery systems can be snaked through conduits, piping, electrical components, walls, lumens, body vessels (e.g., the vascular system), and the like to provide flexibility in gaining access to regions of interest. For the sake of convenience, the light delivery systems will be discussed primarily with respect to medical uses.
In some embodiments, a light delivery apparatus can be used to treat a target site of tissue to promote tissue growth (e.g., cell division, cell growth or enlargement, etc.), increase the rate of healing, improve circulation, reduce or minimize pain, relieve stiffness, and the like. The light delivery apparatus can illuminate different types of tissue, such as muscle, bone, cartilage, or other suitable tissue, without using a treatment agent. One or more light sources of the light delivery apparatus can be configured to emit light with near-infrared or infrared wavelengths. This light itself can cause tissue growth. Alternatively, the light delivery apparatus can be used in combination with growth enhancers, growth factors, and the like.
The light delivery apparatus can also be used to destroy tissue by emitting energy that causes cell destruction. One or more energy sources of the light delivery apparatus can be activated to generate enough heat for cell destruction. If the energy sources are LEDs, the LEDs, when activated, can generate a sufficient amount of heat to cause tissue damage. In other embodiments, the energy sources can emit ultraviolet light that destroys the target cells. Such embodiments are especially well suited for destroying a thin layer of tissue without using a treatment agent or damaging an underlying layer of tissue.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGSIn the drawings, identical reference numbers identify similar elements or acts. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles may not be drawn to scale, and some of these elements may be arbitrarily enlarged and positioned to improve drawing legibility.
FIG. 1 is a side elevational view of a light delivery system having a catheter assembly and control system, according to one illustrated embodiment.
FIG. 2A is a side elevational view of a distal end of the catheter assembly ofFIG. 1, where the distal end includes an array of light sources mounted to an elongate base. Internal components are shown in dashed line.
FIG. 2B is a top schematic view of the distal end of the catheter assembly ofFIG. 1.
FIG. 3A is a side elevational view of the elongate base ofFIG. 2A.
FIG. 3B is a top elevational view of the elongate base ofFIG. 3A.
FIGS. 3C to 3E are axial cross-sectional views of different embodiments of bases suitable for carrying an array of light sources.
FIG. 4 is a side elevational view of an array of light sources mounted to the base ofFIGS. 3A and 3B.
FIGS. 5A and 5B are side and top elevational views, respectively, of a light transmission system, where wires connect adjacent light sources.
FIG. 6 is a side schematic view of a distal end of a catheter assembly having light sources which are flip chip mounted to an elongate base, according to one illustrated embodiment.
FIG. 7 is a top elevational view of the base ofFIG. 6.
FIG. 8A is a side elevational view of one light source positioned above the base ofFIG. 7.
FIG. 8B is a side elevational view of the light source ofFIG. 8A after the light source has been assembled with the base.
FIG. 9 is a top elevational view of an array of light sources linearly mounted to an upper face of the base.
FIG. 10 is a side elevational view of a light source mounted above an aperture extending through a base, according to one illustrated embodiment.
FIG. 11 is a side schematic view of a distal end of a catheter, where an array of light sources is within an encapsulant.
FIG. 12A is a top elevational view of a portion of a light transmission system, according to one illustrated embodiment.
FIG. 12B is a cross-sectional view of the light transmission system ofFIG. 12A taken alongline12B-12B.
FIG. 13 is an axial cross-sectional view of the light transmission system ofFIG. 12A, where the light transmission system is within an encapsulant.
FIG. 14A is a top elevational view of a circuit having traces coupled to a base.
FIG. 14B is a bottom elevational view of the circuit ofFIG. 14A.
FIG. 15A is a top elevational view of circuit having traces coupled to a base, according to another illustrated embodiment.
FIG. 15B is a bottom elevational view of the circuit ofFIG. 15A.
FIG. 16A is a top elevational view of a circuit having traces coupled to a base, in accordance with another illustrated embodiment.
FIG. 16B is a distal portion of the circuit ofFIG. 16A.
FIG. 16C is a central portion of the circuit ofFIG. 16A.
FIG. 16D is a proximal portion of the circuit ofFIG. 16A.
FIG. 17 is a cross-sectional view of a pair of light sources mounted to a multilayer circuit.
FIG. 18A is a circuit diagram of one embodiment of a light bar circuit.
FIG. 18B is a circuit diagram of another embodiment of a light bar circuit.
FIG. 19 is a perspective view of an empty manufacturing tool for holding the light sources ofFIG. 11.
FIG. 20 is a perspective view of the manufacturing tool ofFIG. 19, where the manufacturing tool is holding an array of light sources connected by wires.
FIG. 21 is an enlarged perspective view of the light sources, wires, and manufacturing tool illustrated inFIG. 20.
FIG. 22 is a side elevational schematic view of a distal tip having a two-sided light source array in accordance with one embodiment.
FIG. 23 is a schematic cross-sectional view of a distal tip having a two-sided light source array in accordance with another embodiment.
DETAILED DESCRIPTION OF THE INVENTIONFIG. 1 is a side elevational view of alight delivery system100 including acontrol system106 and acatheter assembly110 extending distally from and coupled to thecontrol system106, according to one embodiment. Thelight delivery system100 can be used to perform various types of light therapy. Light therapy is broadly construed to include photo-activating or photo-exciting one or more target cells by subjecting the one or more target cells to one or more wavelengths of light that are approximately close to, if not equivalent to, at least one excitation wavelength of the target cells. This photo-excitation process can be used during an oncology treatment program, for example, to treat diseased or otherwise undesirable and/or cancerous target cells. It is understood that even if one cell is “targeted,” it is possible that other cells in a vicinity of the targeted cell may also be subjected to light. Thelight delivery system100 can be used to treat other types of abnormal cells.
Thecatheter assembly110 includes adistal tip114 and acatheter body116 extending between thedistal tip114 and thecontrol system106. Thedistal tip114 includes a transmission system120 (shown in phantom) configured to output energy, such as radiant energy, suitable for treating a target region in the patient. Once thedistal tip114 is positioned at the target site, thecontrol system106 can be utilized for selectively controlling the output from thedistal tip114.
Thecontrol system106 can include acontroller124 and a power supply126 (shown in phantom inFIG. 1) in communication with thetransmission system120. Thecontroller124 can be operated to select the amount of radiant energy emitted by thelight transmission system120.
The illustratedinternal power supply126 is a battery, such as a lithium battery. In other embodiments, thelight delivery system100 is powered by an AC power source, such as an electrical outlet typically found at a hospital, medical facility, or other suitable location for performing light therapy. Thecontrol system106 can include a power cord that can be connected to the AC power source. Accordingly, various types of internal and/or external power sources can be utilized to power thelight delivery system100.
Thecatheter assembly110 ofFIG. 1 has a low profile configuration suitable for percutaneous advancement and navigation within a patient. Such a construction allows convenient delivery and placement of thedistal tip114 at remote locations within a patient, unlike catheters with larger light bars. Thecatheter assembly110 can also be dimensioned for other means of delivery and placement. For example, thecatheter assembly110 can be configured for external light delivery (e.g., transcutaneous or transdermal delivery). This external catheter assembly can be larger than the percutaneously delivered catheter assembly described above. Accordingly, the dimensions (e.g., the axial length, cross-sectional width, etc.) thecatheter assembly110 can be selected based upon the accessibility of the target tissue.
Thecatheter assembly110 can have a cross-sectional width that is less than about 1.25 mm. In some embodiments, thecatheter assembly110 has a cross-sectional width that is less than about 1 mm. In some embodiments, thecatheter assembly110 has a cross-sectional width that is less than about 0.80 mm. In some embodiments, thecatheter assembly110 has a cross-sectional width that is less than about 0.75 mm. In some embodiments, thecatheter assembly110 has a cross-sectional width that is less than about 0.70 mm. The distal tip can have a cross-sectional width less than about 10 mm, 5 mm, 1.5 mm, 1.25 mm, 1.0 mm, 0.75 mm, 0.5 mm, and ranges encompassing such widths. Other dimensions are also possible.
In some embodiments, thelight delivery system100 can be used as an adjunct during another medical procedure, such as minimally invasive procedures, open procedures, semi-open procedures, or other surgical procedures that preferably provide access to a desired target region. Many times, the access techniques and procedures used to provide access to a target region can be performed by a surgeon and/or a robotic device, such as robotic systems used for performing minimally invasive surgeries. Those skilled in the art recognize that there are many different ways that a target region can be accessed. Optionally, thelight delivery system100 is used with guidewires, delivery sheaths, delivery devices (e.g., endoscopes, bronchoscopes, optical instruments, etc.), introducers, trocars, biopsy needle, or other suitable medical equipment. If the target treatment site is at a distant location in the patient, delivery devices should be used for convenient navigation through tortuous body lumens or other anatomical structures in the patient. The flexiblelight delivery system100 can be easily positioned within the patient using, for example, steerable devices, such as endoscopes, bronchoscopes, and the like. Semi-rigid or rigidlight delivery systems100 can be delivered using trocars, access ports, rigid delivery sheaths using semi-open procedures, open procedures, or other delivery tools/procedures that provide a somewhat straight delivery path, for example. Advantageously, the semi-rigid orrigid system100 can be sufficiently rigid to displace internal tissue to help facilitate light delivery to the target tissue. When inserted in the patient, thesystem100 can be easily rotated and advanced axially while maintaining its configuration.
FIGS. 2A and 2B show thedistal tip114 including thetransmission system120 encapsulated in a protectiveouter body136. When thetransmission system120 is activated, radiant energy is delivered from thetransmission system120 through theouter body136 to the desired target region, preferably tissue near theouter body136 such that an effective amount of radiant energy reaches the target region.
Thetransmission system120 includes one ormore energy sources138 mounted onto abase142. As used herein, the term “energy source” is a broad term and includes, but is not limited to, energy sources capable of emitting radiant energy, such as electromagnetic energy. Non-limiting exemplary energy sources can be light sources capable of emitting visible light waves, non-visible light waves, and combinations thereof. The energy sources can be LEDs (such as edge emitting LEDs, surface emitting LEDs, super luminescent LEDs), laser diodes, or other suitable energy sources.
FIGS. 2A and 2B illustrate a linear array ofLEDs138 spaced apart along the length of thedistal tip114. In the illustrated embodiment, theLEDs138 are coupled upon a longitudinally extendingupper face200 of theelongate base142. Aconductive connector148 interconnects theLEDs138 so as to distribute electrical energy between the LEDs. The term “conductive connector” is a broad term and includes, without limitation, lead(s), wire(s) (preferably flexible wires), bus bar(s), a conductive film or ink applied to a substrate, or other conductor suitable for electronically coupling theLEDs138 to thecontrol system106. In the illustrated embodiment ofFIGS. 2A and 2B, theconductive connector148 is a plurality ofleads150 formed by a pair ofwires160,162 extending above and coupled to theLEDs138, thereby forming a complete circuit.
TheLEDs138 can be arranged in parallel, series, or combinations thereof. For example, someLEDs138 can be arranged in series while other LEDs are arranged in parallel. As such, various circuit configurations can be used when mounting theLEDs138 to thebase142. Exemplary non-limiting embodiments of circuits are discussed below in detail.
With continued reference toFIG. 2B, eachLED138 haselectrodes170,172 coupled to thewires160,162, respectively. EachLED138 can also include one or more layers 180 (e.g., GaN layers, AlGaN layers, InGaN layers, AlInGap AlInGaP layers and/or AlInGaN layers) disposed between theelectrodes170,172 and asubstrate182, as shown inFIG. 2A. In the illustrated embodiment, thesubstrate182 is a transmissive substrate. For example, thesubstrate182 can be optically transparent to the light emitted from the layer(s) described above.
The illustratedLEDs138 can emit appropriate wavelength(s) or waveband(s) suitable for treating the patient, with or without using a treatment agent. If a treatment agent (e.g., a photo-reactive or photosensitive agent) is utilized, theLEDs138 preferably emit radiation wavelength(s) or waveband(s) that corresponds with, or at least overlap with, the wavelength(s) or waveband(s) that excite or otherwise activate the agent. Photosensitive agents can often have one or more absorption wavelengths or wavebands that excite them to produce substances which damage, destroy, or otherwise treat target tissue of the patient. For example, theLEDs138 can be configured to emit light having a wavelength or waveband in the range from about 400 nanometers to 1,000 nanometers. In some embodiments, theLEDs138 emit a wavelength or waveband in the range from about 600 nanometers to about 800 nanometers. In some embodiments, theLEDs138 emit a wavelength or waveband in the range from about 600 nanometers to about 700 nanometers. In one embodiment, for example, theLEDs138 emit radiation with a peak wavelength of 664 nanometers plus or minus 5 nanometers.
EachLED138 of thedistal tip114 can be configured be to emit the same wavelength or waveband. However, LEDs having different wavelengths or wavebands can be used to provide varying outputs. TheseLEDs138 can be activated simultaneously or at different times depending on the desired treatment. Thevarious LEDs138 can also be activated and deactivated in a pulsed sequence. For example, theLEDs138 may form two halves of the light array which are alternately turned on and off. Alternately, the system may be programmed to selectively activate and deactivate different selected segments ofLEDs138 along the length of the light bar. In this manner, a treatment protocol, for example causing the LEDs to be lit in a certain sequence, at a particular power level for a selected period of time, may be programmed into thecontrol system106.
Thedistal tip114 can have any number ofLEDs138. In the illustrated embodiment, five LEDs are positioned generally along the longitudinal axis of thedistal tip114. However, a higher or lower number of LEDs can be selected based on the desired energy output, emitted wavelength(s) and/or waveband(s), surface area of target site, desired level of energy penetration, and other treatment parameters. In some embodiments, for example, about 60 LEDs are spaced along thedistal tip114 at a 1 mm pitch. In other embodiments, the LEDs can be at a pitch in the range of about 1.5 mm to about 0.5 mm. In some embodiments, less than 70 LEDs are spaced along thedistal tip114. In other embodiments, less than 50 LEDs are spaced along thedistal tip114. In yet other embodiments, less than 40 LEDs are spaced along thedistal tip114. The illustratedLEDs138 are evenly spaced and form a single row; however, other LEDs arrangements are possible. For example, thedistal tip114 can include a matrix ofLEDs138.
As described above in connection withFIGS. 2A and 2B, theLEDs138 are mounted upon theupper face200 of thebase142. Any suitable mounting means can be employed to temporarily or permanently couple theLEDs138 onto thebase142. For example, adhesives, bonding material, fasteners, solder, or other coupling means can securely couple theLEDs138 to thebase142. The mounting means can be optically transparent in order to transmit light generated by theLEDs138 to the base142 which, in turn, transmits light that ultimately reaches the patient. In the illustrated embodiment ofFIGS. 2A and 2B, optically transparent epoxy permanently couples the linearly spacedLEDs138 to theupper face200.
With continued reference toFIGS. 2A and 2B, thebase142 is an elongate member that extends longitudinally along thedistal tip114, and provides a relatively large mounting area on theupper face200 for convenient placement of theLEDs138. The base can be a support substrate sized to hold any number of LEDs.
Thebase142 is preferably sufficiently flexible so as to permit enough distortion of thedistal tip114 for delivery along a tortuous path. The base142 can be twisted, bent, rolled, and/or otherwise distorted, preferably without any appreciable damage to thebase142 and/orLEDs138 mounted thereto. In some embodiments, the base142 can be moved through an angle of 220°, 180°, 150°, 130°, 90°, 70°, 50°, and ranges encompassing such angles.
In some embodiments, thebase142 is a thin, flat strip of a flexible material. Thethin base142 helps reduce the profile of thelight transmission system120 and, consequently, the overall cross-sectional width of thedistal tip114. Furthermore, the base142 can be easily bent and twisted to allow navigation along tortuous paths within the patient, thus permitting flexibility in selecting treatment protocols.
The base142 can have a polygonal axial cross-section (e.g., a rectangular cross-section), elliptical cross-section, or other suitable axial cross-section.FIGS. 3C to 3E illustrate various axial cross-sections of thebase142.
Various materials can be used to construct thebase142. Flexible, semi-rigid, and/orrigid bases142 can be made of rubber, composite materials, thermoplastics, polymers (e.g., polyester, polyethylene terephthalate (PET), polypropylene, polyethylene naphthalate (PEN), and combinations thereof. In one embodiment, thebase142 comprises a somewhat transparent material, preferably an optically transparent polyester. At least one wavelength of light emitted by the LEDs can pass through thebase142, as discussed in more detail below.
The material(s) forming the base142 can be selected to achieve the desired structural properties, thermal properties, electrical properties, optical properties, and durability. For example, to dissipate heat generated by theLEDs138, the base142 can comprise a heat conductive material that can act as a heat sink for conducting heat away from the LEDs in order to maintain thelight transmission system120 at an appropriate operating temperature. Additionally, one or more ribs, stiffeners, joints, reinforcement members, strain relief elements, or other structural elements can be added to the base142 to achieve the desired properties. As noted above, thebase142 may be somewhat rigid for some medical applications. For example, a base142 indistal tip114 for applying light externally to the patient may be a rigid member comprised of metal, rigid plastic, or other suitably stiff material.
As mentioned above, the base142 can comprise a transmissive material to allow light emitted from the LEDs to pass therethrough. Thus, the base142 advantageously supports theLEDs138 while also permitting the passage of light therethrough to increase the efficacy of the light treatment and decrease power consumption. Further, the base142 can be relatively large for an enlarged LED mounting zone without appreciably reducing the amount of light reaching the target tissue. This results in easy placement of the LEDs.
Suitable transmissive materials include, but are not limited to, polymers such as polyester, PET, polypropylene, combinations thereof and the like. One or more layers of material can form thebase142. Preferably, a substantial amount of the light directed from theLEDs138 towards thebase142 is transmitted through thebase142. In some embodiments, at least 40% of the light emitted towards thebase142 is transmitted therethrough. In some embodiments, at least 50% of the light directed towards thebase142 is transmitted therethrough. In some embodiments, at least 60% of the light directed towards thebase142 is transmitted therethrough. In some embodiments, at least 70% of the light directed towards thebase142 is transmitted therethrough. In some embodiments, at least 80% of the light directed towards thebase142 is transmitted therethrough. In some embodiments, at least 90% of the light directed towards thebase142 is transmitted therethrough. Additionally, one or more light passageways, through-holes, windows, or other structures can be formed in the base142 to increase the amount of light passing through thebase142.
The base142 can optionally include one or more opaque materials that can inhibit or prevent one or more wavelengths or wavebands from passing therethrough. Opacification agents, additives, coatings, or combinations thereof can be utilized to render the base142 (or portion thereof) somewhat opaque. In some embodiments, the opacification agents include, but are not limited to, dyes, pigments, metal particulates or powder, or other materials that can be coated onto, disbursed throughout, or otherwise disposed in thebase142. If desired, the base142 can function as a filter so as to inhibit or prevent one or more wavelengths or wavebands from reaching the patient's tissue.
In some embodiments, thebase142 extends proximally from thedistal tip114 along the entire length of thecatheter body116. In other embodiments, a proximal end of thebase142 is positioned distally of the proximal end of thecatheter assembly110. For example, the proximal end of the base142 can be positioned at some point along thecatheter body116, or within thedistal tip114.
As shown inFIGS. 2A and 2B, thelight transmission system120 is housed within theouter body136, as discussed above. Theouter body136 is preferably transmissive so as to transmit radiation emitted from thelight transmission system120. For example, theouter body136 can be made of the same material(s) forming thebase142. During advancement through the patient's body and placement at the target site, external forces may be applied to thedistal tip114. Accordingly, theouter body136 can be made of a material suitable for limiting or preventing undesirable damage to thelight transmission system120.
Theouter body136 can define achamber206 sized to accommodate thelight transmission system120. In some embodiments, an encapsulate (e.g., a polymer) can be used to fill thechamber206 in order to minimize or prevent movement of thelight transmission system120 relative to theouter body136. Alternatively, theouter body136 can define ahollow chamber206 which can increase the overall flexibility of thedistal tip114. Optionally, theouter body136 can be an expandable member, such as those disclosed in the '357 patent application, which is hereby incorporated by reference in its entirety. Thechamber206 can be filled with an inflation fluid to inflate theouter body136. In other embodiments, theouter body136 is a monolithic protective outer member, such as a member molded over the light transmission system. Accordingly, theouter body136 can have a one-piece or multi-piece construction.
FIGS. 3A, 3B, and 4-5B illustrate one embodiment of a process to produce adistal tip114 using wire bonding techniques.FIGS. 3A to 3E show the base142 which is the starting material for forming thedistal tip114.LEDs138 are attached to theupper surface200 of thebase142, as shown inFIG. 4. Thebase142 maintains the desired spacing between themounted LEDs138 while thewire bonds150 are formed. In this manner, thebase142 helps to improve the tolerances between the LEDs, even though the LEDs may be subjected to subsequent processing. In the illustrated embodiment ofFIG. 5A, for example, the pair ofwires160,162 are connected to theelectrodes170,172, respectively, with solder while theLEDs138 remain securely mounted to thebase142. Accordingly, the base142 can function as a LED holder thus reducing fabrication time and improving tolerances. Additionally, the base142 can be made of a low cost material (e.g., polyester) that is ultimately integrated into thedistal tip assembly114 thereby reducing material waste and cost.
After assembling the transmission system120 (as shown inFIGS. 5A and 5B), theouter body136 can be formed by various molding techniques. For example, theouter body136 can be formed through a molding process (e.g., an injection molding process, compression molding process, etc.), thermoforming, machining process, or combinations thereof. In some embodiments, thelight transmission system120 can be placed in a mold cavity corresponding to the desired shape of theouter body136. To oversold thelight transmission system120, a molten polymer can be injected into the mold cavity. Alternatively, theouter body136 can be a preformed hollow member. Thelight transmission system120 can be inserted into the member until thedistal tip114 is fully assembled.
FIG. 6 shows another embodiment of a distal tip that can be incorporated into thelight delivery system100 ofFIG. 1. Thedistal tip300 ofFIG. 6 may be generally similar to thedistal tip114 illustrated inFIG. 1, except as further detailed below.
Thedistal tip300 ofFIG. 6 has an array ofLEDs304 that are mounted in a flip chip arrangement. A flip chip is one type of integrated circuit (IC) chip mounting arrangement that does not require wire bonding between chips (e.g., the chip mounting arrangement described above in connection withFIGS. 1-5B). Thus, wires or leads that typically connect a chip/substrate having connective elements can be eliminated to further reduce the profile of the distal tip. That is, thedistal tip300 can have a lower profile than thedistal tip114 and is well suited for delivery along narrow passageways. By way of example, thedistal tip114 ofFIG. 1 can have a diameter in the range of about 1.5 mm to about 1.2 mm, although other diameters are also possible. The flip chip mounteddistal tip300 ofFIG. 6 has a diameter in the range of about 0.8 mm to about 0.7 mm. In some embodiments, thedistal tip300 has a diameter of about 0.74 mm. Thus, thedistal tip300 can be delivered along relatively narrow delivery paths, while providing the same output as the wire bondeddistal tip114.
FIGS. 7-10 illustrate one embodiment of a process to produce adistal tip300 ofFIG. 6 having flip chip mounted LEDs. Generally, instead of wire bonding described above, solder beads or other elements can be positioned or deposited on chip pads such that when the chip is mounted upside-down in/on the substrate, electrical connections are established between conductive traces of the substrate and the chip.
FIG. 7 illustrates acircuit309 including abase310 and an array of conducting traces orelectrodes314,316 suitable for flip chip mounting. As shown inFIG. 8A, anLED304 can be positioned above the pair of thetraces314,316.Solder beads320 are formed on theelectrodes324 of theLED304 such that when theLED304 is lowered onto thecircuit309, preformed solder beads can electrically and mechanically connect the LED to thetraces314,316 of thebase310. After one or more of theLEDs304 are placed upon thebase310, thesolder beads320 can be heated or thermally treated until the solder securely couples theLEDs304 to thebase310, as shown inFIG. 8B. After theLEDs304 are mounted onto thebase310, anouter body330 can be formed in the manner described above.
Thebase310 ofFIG. 7 can comprise the same materials as thebase142 ofFIGS. 2A and 2B. However, the base310 can also be formed of other materials. For example, the base310 can be formed of a polyamide material (e.g., polyimide flex) that is especially well-suited for flip chip mounting arrangements. To increase the amount of light passing through thebase310, one or more light passageways can be formed in thebase310. A light passageway can be a through-hole, window, transmissive material(s), or other suitable element for increasing the amount of light traveling through thebase310. The number and/or size of the light passageways can be increased or decreased to increase or decrease, respectively, the amount of transmitted light.
FIG. 10 shows a light passageway334 (shown in phantom) in the form of a through-hole in thebase310. As such, light emitted from theLED304 can pass easily through thebase310 via thelight passageway334. Thelight passageway334 can be formed before, during, or after theLED304 is mounted to thebase310. For example, theLED304 can be mounted onto a pre-formedperforated base310. Preferably, thelight passageways334 are positioned so as to effectively transmit light from the LED through thebase310.
FIG. 11 shows another distal tip that can be incorporated into thelight delivery system100 ofFIG. 1. Thedistal tip400 may be generally similar to thedistal tip114 illustrated inFIG. 1, except as further detailed below.
Thedistal tip400 ofFIG. 11 has a light transmission system including a plurality oflight sources410 that are wire bonded together by a plurality ofconductive elements412 in the form of leads. Advantageously, thedistal tip400 can be formed without utilizing the support bases as described above. The light transmission system can be directly mounted in theouter body406, so as to reduce the number of components forming the tip. Additionally, the support bases described above may inhibit the passage of light therethrough thereby limiting the illumination of the tissue. Thus, thedistal tip400 can be used to deliver an increased amount of light.
The stress on theleads412 ofFIG. 11 may be less than the stress experienced by theleads150 ofFIGS. 2A and 2B because thebase142 ofFIG. 2A may help define the bend axis ofdistal tip114. As such, the base142 can cause the bend axis to be spaced an undesirable distance from the leads resulting in increased axial stresses in the leads when thedistal tip114 is bent. InFIG. 11, however, a support base does not move the bend axis away from theleads412. Accordingly, theleads412 can be positioned near or at the neutral axis of thedistal tip400, thereby reducing or eliminating axial stresses on the leads. In some embodiments, leads412 can act as pivot points defining the bending axis of thedistal tip400, if desired.
FIGS. 12A and 12B illustrate alight transmission system340 having a plurality of flip chip mounted light sources352A,352B coupled to acircuit353. Abase354 of thecircuit353 defines one ormore locking structures360 for enhancing coupling between an encapsulant and thelight transmission system340. As shown inFIG. 13, anencapsulant362 can surround thelight transmission system340, and aportion363 of theencapsulant362 can pass through the lockingstructure360 extending through thebase354. As such, the lockingstructure360 can minimize, limit, or prevent movement between thelight transmission system340 andencapsulant362. Additionally, the lockingstructure360 can advantageously inhibit or prevent delamination of the encapsulant362 from thebase354.
The illustratedlocking structure360 ofFIGS. 12A to 13 is a through-hole having an elongated axial cross-section. In some non-limiting exemplary embodiments, the lockingstructure360 has a width of about 0.005 inch (0.127 mm) and a length of about 0.011 inch (0.28 mm) and is located between two light sources352A,352B, each having a length and width of about 0.014 inch (0.356 mm). The size of the lockingstructure360 can be increased or decreased to increase or decrease, respectively, the amount of theencapsulant363 extending through thebase354. In other embodiments, the lockingstructure360 can have a polygonal (including rounded polygonal), elliptical, circular, or any other suitable cross-section. A drilling process, machining process, or other suitable process can be used to form thestructure360.
With reference again toFIG. 12A, thelight transmission system340 includes a pair of generally longitudinally-extendingtraces364,366 interposed between the light sources352A,352B andbase354. Thetraces364,366 interconnect adjacent pairs of light sources352A,352B. To accommodate anenlarged locking structure360, the distance between portions of thetraces364,366 can be increased, as shown inFIG. 12A. In the illustrated embodiment ofFIG. 12A, the distance D1 between thetraces364,366 is greater than the distance D2 between the portions of thetraces364,366 adjacent or beneath the light sources352A,352B. The spacing between thetraces364,366 can be selected based on the size, position, and/or configuration of the lockingstructure360.
The other light transmission systems disclosed herein can also include one or more locking structures. For example, thebase142 ofFIG. 2A can include one or more locking structures interposed between adjacent pairs of wire bonded LEDs. Thus, locking structures can be used with wire bonded LEDs, flip chip LEDs, and other chip mounting arrangements.
With continued reference toFIGS. 12A and 12B, thetraces364,366 are delivery traces connecting the light sources352A,352B. Thebase354 is interposed between the delivery traces364,366 and return traces368,370. A coverlay361 (shown removed inFIG. 12A) can overlay at least a portion of both thebase354 and thetraces364,366,368,370, as shown inFIG. 12B.
The light delivery systems described herein can have circuits with different configurations. The configurations of the circuits can be selected to achieve the desired output from each light source.FIGS. 14A to 16D illustrate circuits that can be used in the light delivery systems disclosed herein.FIG. 14A illustrates acircuit371 including atrace system369 having a plurality oftraces372,373,374 coupled to abase375.Bonding pads376 are positioned to receive the light sources377 (shown in phantom).
At least one of thetraces372,373,374 can be a cross-over trace. In the illustrated embodiment ofFIG. 14A, thetrace374 is a cross-over trace and includes a pair of opposing longitudinally-extending side portions374A,374B and a cross-over trace374C extending laterally between the side portions374A,374B. In this manner, thetrace374 can connect opposing connectors of adjacentlight sources377. Thecircuit371 can have any number of traces as desired.
A pair of return traces378,379 ofFIG. 14B is coupled to the bottom surface of thebase375 and can increase the current carrying capability of the light delivery system without blocking a substantial amount of light emitted from thelight sources377. The return traces378,379 can be positioned directly opposite portions of thetraces372,373,374 such that thetraces378,379 do not increase the amount of blocked light. In some embodiments, the width of thetraces378,379 can be generally equal to or less than the width of the opposing portions of the correspondingtraces372,373,374.
FIGS. 15A and 15B illustrate another circuit for a light delivery system. Atrace system380 has segments that provide independent activation of one or more groups of light sources. The illustratedtrace system380 includes a plurality of traces381A-D mounted to thebase382. A controller or switch384 for selectively controlling current flow is positioned between the traces381B,381C. Thecontroller384 can thus determine the current flow to distal light sources (not shown). The illustratedtrace system380 has asingle controller384; however, any desired number of controllers can be used to separate one or more light sources.
FIGS. 16A to 16D show a light transmission system in accordance with one embodiment. The illustratedlight transmission system385 ofFIG. 16A has a distal portion386 (FIG. 16B), proximal portion387 (FIG. 16D), and central portion388 (FIG. 16C) extending therebetween. A pair of traces389A,389B extend along the length of thetransmission system385. Abase413 is positioned between the traces389A,389B. As shown inFIGS. 16B to 16D, light sources415 (shown in phantom) can be spaced from each other along thelight transmission system385. The traces389A,389B are preferably spaced laterally from thelight sources415 for improved transmission through thebase413. In one embodiment, thebase413 is transparent.
The illustratedlight transmission system385 can have a single or double sided mounting arrangement. The material of the base413 can be removed to improve the optical properties of thebase413. Laser and/or mechanical muting techniques can be used to remove a portion (e.g., a substantial portion) of the material of the base413 positioned adjacent and/or beneath a plurality oflight sources415. Other types of material removal techniques, such as etching, can also be used.
The circuits ofFIGS. 14A to 16D can be used for a one-sided or two-sided flip chip mounting arrangement.FIG. 17 shows a two-sided arrangement having light sources390A,390B mounted to opposing sides of amultilayer board391. Theboard391 includes the light source390A mounted totraces392,393 viasolder394. Thetraces392,393 are mounted to an upper surface of anupper base395. Areturn trace396 is interposed between theupper base395 and alower base397. The light source390B is mounted totraces398,399 viasolder400. Upper and lower coverlays401A,401B can cover and protect thetraces392,393 and traces398,399, respectively. Of course, theboard391 can be transparent to allow the passage of light therethrough.
As noted above, the light transmission systems disclosed herein can have various types of circuit arrangements.FIG. 18A is a circuit diagram403 showing light sources404A-D. The light sources404A,404B are in a parallel arrangement. The light sources404C and404D are likewise in a parallel arrangement. Any desired number of light sources can be arranged in a parallel arrangement. The light sources404A,404B and light sources404C,404D form groups405,406, respectively, that are arranged in series. Any number of light source groups can be arranged in series.FIG. 18B illustrates a plurality of light sources407A-C in a series arrangement.
FIGS. 19 and 23 show methods of producing distal tips for light delivery systems.FIGS. 19 to 21 illustrate one embodiment of a process to produce a distal tip, such as thedistal tip400 ofFIG. 11 as detailed below.
FIG. 19 shows afixture device440 that is configured to receive and hold theLEDs410 during assembling. The illustratedfixture device440 includes an array ofholders442 and a pair ofelongated slots448 extending along inwardly from one side of thefixture device440. Theholders442 are sized and configured to receive at least a portion of theLEDs410. The pattern of theholders442 corresponds to the desired pattern of the LEDs. Eachholder442 comprises a mountingportion444 and a throughhole446. The mountingportion444 can be a recess configured to receive at least a portion of the LEDs. Alternatively, the mountingportions444 can be one or more protrusions, keying structures, or other suitable structure for engaging and holding an LED.
In the illustrated embodiment, to place theLEDs410 within acorresponding holder442, the bottom portion of eachLED410 is placed within a corresponding mountingportion444 such that the electrodes of the LED are facing outwardly, as shown inFIG. 20. To ensure that the LEDs are properly retained in theircorresponding holders442, a vacuum can be applied via the throughhole446. Optionally, the mountingportions444 can have sealing members (e.g., rubber inserts, compliant flanges, etc.) to form a seal between the LEDs andholders442. Preferably, the vacuum is continuously applied while wire leads are attached to the electrodes of the LEDs.
As shown inFIG. 20, wires extending from the outermost LED can pass through theslots448 which function as wire holders. In this manner, thefixture device440 can effectively hold the LEDs and wires in desired locations to ensure proper positioning and alignment. Once thelight transmission system450 is assembled (as shown inFIG. 20), thelight transmission system450 can be removed from thefixture device440 for subsequent processing. If a vacuum was applied during assembling, the vacuum can be reduced or eliminated to permit easy removal of the LEDs from thefixture device440. In some embodiments, a positive pressure is applied to release the LEDs from the tool. The assembled LEDs can then be place in a mold and encapsulated with material to the desired final dimensions, as discussed in connection withFIG. 23.
The distal tips described above can be modified to have light sources facing any number of directions.FIG. 22 shows adistal tip500 having a two-sidedlight transmission system510. Thelight transmission system510 is interposed between a first array oflight sources524 and second array oflight sources528. In the illustrated embodiment, the wire bondedlight sources524,528 are mounted to upper andlower faces532,536, respectively, of thebase510. Thelight sources524,528 can advantageously directly light in different directions, preferably in substantially opposite directions. The illustratedlight sources524,528 can be applied to thebase510 by using the process illustrated inFIGS. 3A to 5B. In other embodiments, a two-sided light transmission system includes flip chip mounted light sources mounted to upper and lower faces of a base, preferably formed by the process illustrated inFIGS. 7 to 9. Thus, light sources can be applied to any number of faces of a mounting substrate.
FIG. 23 shows a distal portion of alight transmission system600 having a two-side chip mounting arrangement. Thelight sources602,604 are encapsulated in aninner portion606. Anouter portion608 is disposed over theinner portion606.
Theinner portion606 can be formed through a casting or molding process, such as an injection molding process. Theinner portion606 andlight sources602,604 can then be inserted into theouter portion608. In one embodiment, theouter portion608 is in the form of a tube. Theouter portion608 can be processed to bond, adhere, or otherwise couple theouter portion608 to theinner portion606. In some embodiments, theouter portion608 is a thermoplastic elastomer tube (e.g., a polyether block amide tube, PEBAX® tube, etc.) that receives theinner portion606. After assembling the inner andouter portions606,608, the assembly is heated to a reflow temperature to cause at least one of theinner portion606 andouter portion608 to flow, thereby coupling the inner andouter portions606,608. This reflow encapsulation process results in a strong bond formed between the inner andouter portions606,608.
In another embodiment, thelight transmission system600 is inserted into theouter portion608. Material is injected into thelumen613 of theouter portion608 to form theinner portion606. In some embodiments, molten polymer is injected into thelumen613 and flows between theouter portion608 andlight transmission system600. The polymer preferably fills the spaces with thelumen613.
The thickness T of theouter portion608 can be selected based on the desired overall axial width of the catheter. In the illustrated embodiment ofFIG. 23, theinner portion606 has a diameter in the range of about 0.015 inch (0.381 mm) to about 0.025 inch (0.635 mm). In some embodiments, the diameter of theinner portion606 is about 0.020 inches (0.508 mm). The thickness T of theouter portion608 can be in the range of about 0.002 inch (0.051 mm) to about 0.007 inch (0.178 mm). In some embodiments, the thickness T is about 0.005 inch (0.127 mm).
Generally, the light delivery systems can be positioned relative to a target site and then activated to deliver light to the target site. The light delivery systems can be used to treat organs, vasculature, tissue (e.g., epithelial tissue, connective tissue, muscle tissue and nerve tissue), and various systems including, but not limited to, organ systems, circulatory systems, and other suitable systems in the patient.
In some embodiments, the light delivery systems are used to treat adipose tissue, such as subcutaneous adipose tissue located directly beneath the skin or adipose tissue (e.g., visceral fat or intra-abdominal fat) located proximate internal organs. After administering a treatment agent, the light delivery systems can be used to remove or otherwise alter these types of adipose tissue. U.S. Patent Publication No. 2005-0085455, which is hereby incorporated by reference in its entirety, discloses various methods, treatment agents, and the like that can be used in combination with the light delivery systems described herein to treat visceral fat.
Visceral fat, such as panniculus adipose tissue, may have a contributory role in medical conditions, such as type II diabetes. The reduction of this visceral fat may improve a patient's condition. If a person is suffering from type II diabetes, for example, the reduction of visceral fat may reverse or improve insulin resistance, diabetes syndrome, and/or metabolic syndrome. This can lead to reduced medical costs associated with diabetes. The frequency and likelihood of complications (e.g., heart disease, renal failure, foot ulcers, and diabetic retinopathy, and the like) of diabetes can also be reduced or eliminated.
In some embodiments, thelight delivery system100 ofFIG. 1 has thecatheter assembly110 dimensioned for insertion (e.g., percutaneous delivery) into and through a patient. Thedistal tip114 can be moved into operative engagement with the patient's visceral fat. Once positioned, thedistal tip114 can illuminate the visceral fat for a desired period of time. In some non-limiting embodiments, for example, thecatheter assembly110 has an outer diameter less than about 1 mm for convenient placement within the patient.
Various delivery techniques can provide access to the visceral fat. A delivery device, such as an introducer or biopsy needle, can be used to access the visceral fat. Thelight delivery system100 can be placed while utilizing a visualization technique (e.g., ultrasound, fluoroscopy, CT, and MRI) to facilitate proper positioning. One or more visualization aids can be provided on thesystem100 to allow easy visualization in situ.
The treatment agent, such as talaporfin sodium, can be administered to the patient by a suitable delivery means. To deliver a therapeutically effective amount of the agent, the agent can be administered intravenously, or by any other suitable means. After the agent is adequately dispersed at the target site, thetransmission system120 is activated to illuminate the target site. For example, thetransmission system120 can be activated for about 1 hour and then removed from the patient. Thetransmission system120 can be stopped automatically or by user input.
The treated adipose cells may break down (e.g., immediately or gradually over an extended period of time) and are subsequently absorbed by the patient's body. In this manner, the amount of visceral fat can be reduced in a controller manner. This procedure can be performed any number of times at different locations until the desired amount of fat has been eliminated. For example, visceral fat can be removed until achieving a noticeable improvement in insulin resistance. Of course, fat at other target sites can also be treated in a similar manner. Thus, fat deposits can be precisely destroyed or eliminated for health or cosmetic reasons. Moreover, because thesystem100 has a low profile, thedistal tip114 can be delivered to remote locations using minimally invasive techniques.
The light delivery systems can also be dimensioned to fit within the vasculature system, such as within lumens of veins or arteries, or other anatomical lumens in the respiratory system, for example. The size of the light delivery system can be selected based the target treatment site and delivery path to the treatment site.
All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, to include U.S. Pat. Nos. 6,958,498; 6,784,460; 6,661,167; and 6,445,011; U.S. Publication No. 2005/0228260; International Patent Application Nos. PCT/US2005/032851 and PCT/US01/44046; and U.S. Provisional Patent Application No. 60/640,382 are incorporated herein by reference, in their entirety. Except as described herein, the embodiments, features, systems, devices, materials, methods and techniques described herein may, in some embodiments, be similar to any one or more of the embodiments, features, systems, devices, materials, methods and techniques described in the incorporated references. In addition, the embodiments, features, systems, devices, materials, methods and techniques described herein may, in certain embodiments, be applied to or used in connection with any one or more of the embodiments, features, systems, devices, materials, methods and techniques disclosed in the above-mentioned incorporated references.
The various methods and techniques described above provide a number of ways to carry out the invention. Of course, it is to be understood that not necessarily all objectives or advantages described may be achieved in accordance with any particular embodiment described herein. Thus, for example, those skilled in the art will recognize that the methods may be performed in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objectives or advantages as may be taught or suggested herein.
Furthermore, the skilled artisan will recognize the interchangeability of various features from different embodiments disclosed herein. Similarly, the various features and steps discussed above, as well as other known equivalents for each such feature or step, can be mixed and matched by one of ordinary skill in this art to perform methods in accordance with principles described herein. Additionally, the methods which are described and illustrated herein are not limited to the exact sequence of acts described, nor are they necessarily limited to the practice of all of the acts set forth. Other sequences of events or acts, or less than all of the events, or simultaneous occurrence of the events, may be utilized in practicing the embodiments of the invention.
Although the invention has been disclosed in the context of certain embodiments and examples, it will be understood by those skilled in the art that the invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses and obvious modifications and equivalents thereof. The materials, methods, ranges, and embodiments disclosed herein are given by way of example only and are not intended to limit the scope of the disclosure in any way. Accordingly, the invention is not intended to be limited by the specific disclosures of preferred embodiments disclosed herein.