WO2024096911A1

WO2024096911A1 - Pdt bend-tolerant light delivery device and dosimetry method

Info

Publication number: WO2024096911A1
Application number: PCT/US2022/079352
Authority: WO
Inventors: Paul Sanders
Original assignee: Lumeda Inc
Current assignee: Lumeda Inc
Priority date: 2022-11-05
Filing date: 2022-11-05
Publication date: 2024-05-10
Anticipated expiration: 2025-05-05

Abstract

In some implementations, a device may include a therapy light source to produce a therapy light and a monitoring light source to produce a monitoring light. The device may include a light delivery fiber having a light delivery end and a reflectance filter positioned on the light delivery end to transmit therapy light and to reflect the monitoring light. The device may include a first detector to receive the monitoring light from the monitoring light source and to output a transmitted detection signal and a second detector to receive the monitoring light from the reflectance filter and to output a reflected detection signal. The device may include a computer processor to determine a monitoring light loss between the monitoring light from the monitoring light source and the monitoring light from the reflectance filter and a light source controller to control the therapy light source based on the monitoring light loss.

Description

PDT BEND-TOLERANT LIGHT DELIVERY DEVICE AND DOSIMETRY METHOD

BACKGROUND

Field of Disclosure

[0001]The present disclosure relates to photodynamic therapy and more specifically to an PDT light delivery device and dosimetry method that is tolerant to tight mechanical bending.

Description of the Related Art

[0002] Light therapy can be used for treatment of conditions in multiple ways. For example, some light therapies involve the delivery of a therapeutic light through a fiber optic device placed proximal to or within a target tumor or cancerous tissue.

[0003] PDT involves completion of a chemical reaction to produce singlet oxygen and other reactive oxygen species to promote tumor cell death. This reaction is dependent on the interplay between its main components: a. type and dose of photosensitizer, b. photosensitizer administration and cellular uptake, and c. total light dose and fluence rate. It is well understood that in practice, PDT efficacy is highly dependent upon proper light dose and fluence rate i.e. dosimetry.

[0004] PDT light delivery in intracorporeal applications of PDT is for the most part performed using optical fibers that are introduced into the application manually by themselves or incorporated within catheters or endoscopic apparatus. Some level of light dosimetry measurement is usually accomplished by one of the following methods (or in combination): sampling and monitoring light injected into the fiber, monitoring backscattered light, placing a companion light-receiving fiber along with the light delivery fiber, or placing photodetectors or translucent catheters near the tissue undergoing PDT light irradiation.

[0005] In some applications, the optical fiber may be subject to mechanical bending that can cause macrobending-induced light leakage, resulting in light loss (attenuation). Light loss due to macrobending is a well-known physical condition in the art of fiber optics. While sufficient light transmission and PDT light delivery can be maintained even under such macrobending conditions, it can lead to significant measurement error in some of the aforementioned light monitoring methods that will have an adverse effect on providing light to a prescribed PDT light dosimetry.

[0006] Recently, a robotically-assisted endoluminal system has been introduced for minimally invasive peripheral lung biopsy (for example see https://www.intuitive.com/en- us/products-and-services/ion). These systems perform fine needle aspiration biopsy (FNAB) to extract cells for pathology/cytology laboratory testing. While minimally invasive biopsy of the lung can be performed using bronchoscopy (transbronchial biopsy), these procedures have limited capability to reach upper portions of the lung, requiring needle biopsy inserted directing into the lung which frequently results in collapsed lung (pneumothorax). These new robotically assisted systems are differentiated in that they have greater flexibility and ability of the machine catheter to reach all segments of the lung to offer a minimally invasive means to perform FNAB on all segments of the lung. Of note is the fully articulating catheter and flexible needle to move 180° in all directions to reach upper nodules that require the catheter to make such a bend (i.e. a u-turn). By virtue of this capability to reach all nodules these minimally invasive procedures promise to play an increasing and important role in lung cancer biopsy.

[0007] What is needed is a device and method for monitoring PDT light for proper dosimetry tolerant to a full range of macrobending.

SUMMARY OF THE INVENTION

[0008]A system of one or more computers can be configured to perform particular operations or actions by virtue of having software, firmware, hardware, or a combination of them installed on the system that in operation causes or cause the system to perform the actions. One or more computer programs can be configured to perform particular operations or actions by virtue of including instructions that, when executed by data processing apparatus, cause the apparatus to perform the actions.

[0009] In one general aspect, an optical light delivery system may include a therapy light source configured to produce a therapy light. The optical light delivery system may also include a monitoring light source configured to produce a monitoring light. The system may furthermore include a light delivery fiber having a light delivery end. The system may in addition include a reflectance filter positioned on the light delivery end configured to transmit the therapy light and configured to reflect the monitoring light. The system may moreover include a first detector configured to receive the monitoring light from the monitoring light source and to output a transmitted detection signal. The system may also include a second detector configured to receive the monitoring light from the reflectance filter and to output a reflected detection signal. The system may furthermore include a computer processor electrically coupled to the therapy light source, the first detector and the second detector and configured to determine a monitoring light loss between the monitoring light from the monitoring light source and the monitoring light from the reflectance filter. The system may in addition include a light source controller electrically coupled to the computer processor the therapy light source and configured to control the therapy light source based on the monitoring light loss. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.

[0010] Implementations may include one or more of the following features. The optical light delivery system may include a conveying optical fiber coupled to the light delivery fiber, an optical combiner in optical communication with the therapy light source and the monitoring light source configured to combine the therapy light and the monitoring light onto the conveying optical fiber, and a second tap coupler in optical communication with the conveying optical fiber and the first detector and configured to deliver the monitoring light from the reflectance filter to the second detector. The optical light delivery system where the monitoring light loss is determined by differencing the transmitted detection signal and the reflected detection signal. The optical light delivery system where the light source controller is configured to control the therapy light source to produce the therapy light at an initial therapy power level and to control the monitoring light source to produce the monitoring light at an initial monitoring power level. The optical light delivery system where the light source controller is configured to control the therapy light source to produce the therapy light at an updated therapy power level based on the monitoring light loss. The optical light delivery system where the updated therapy power level may include an increase of power substantially equal to twice the monitoring light loss. The optical light delivery system where the updated therapy power level is configured to emit the therapy light at the light delivery end at a predetermined fluence rate. The optical light delivery system where the therapy light emitted at the light delivery end is delivered to a target area of a patient. The optical light delivery system where the therapy light is delivered to the target area of the patient for a predetermined period of time to deliver a total dose of the therapy light. The optical light delivery system may include a treatment plan having the therapy light having a first wavelength, the monitoring light having a second wavelength, the predetermined fluence rate, the total dose, and the computer processor configured to execute the treatment plan. The optical light delivery system where the treatment plan further may include a photosensitizer drug and where the first wavelength is configured to activate the photosensitizer drug. The optical light delivery system where the treatment plan further may include administering the photosensitizer drug to the patient. The optical light delivery system where the first wavelength may include a first range of 630nm-710nm and where the second wavelength may include a second range of 780nm-830nm. The optical light delivery system where at least a portion of the monitoring light loss may include a macrobending loss. The optical light delivery system where the macrobending loss is caused by a bending of the light delivery fiber. The optical light delivery system where the monitoring light loss is substantially equal to twice a therapy light loss. The optical light delivery system may include a narrow band optical filter positioned between the second tap coupler and the second detector and configured to transmit the monitoring light and to block the therapy light. The optical light delivery system may include a robotically-assisted endoluminal system having a catheter and where the light delivery fiber is disposed within the catheter. The optical light delivery system may include an optical diffuser coupled to the reflectance filter. Implementations of the described techniques may include hardware, a method or process, or a computer tangible medium.

[0011] In one general aspect, a method may include producing a therapy light. The method may also include producing a monitoring light. The method may furthermore include providing a light delivery fiber having a light delivery end. The method may in addition include combining the therapy light and the monitoring light. The method may moreover include delivering the therapy light and the monitoring light. The method may also include reflecting the monitoring light from the light delivery end. The method may furthermore include transmitting the therapy light from the light delivery end. The method may in addition include monitoring the monitoring light and outputting a transmitted detection signal. The method may moreover include monitoring the monitoring light reflected from the light delivery end and outputting a reflected detection signal. The method may also include determining, using a computer processor, a monitoring light loss between the transmitted detection signal and the reflected detection signal. The method may furthermore include controlling, using the computer processor and a light source controller, producing the therapy light based on the monitoring light loss. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.

[0012] Implementations may include one or more of the following features. The method where determining the monitoring light loss may include differencing the transmitted detection signal and the reflected detection signal. The method where producing the therapy light may include an initial therapy power level and producing the monitoring light may include an initial monitoring power level. The method may include determining, using the computer processor, an updated therapy power level based on the monitoring light loss and controlling producing the therapy light using the updated therapy power level. The method where the updated therapy power level may include an increase of power substantially equal to twice the monitoring light loss. The method may include emitting the therapy light at the updated therapy power level at the light delivery end and at a predetermined fluence rate. The method may include delivering the therapy light emitted at the light delivery end to a target area of the patient. The method where the delivering the therapy light may include delivering the therapy light to the target area of the patient for a predetermined period of time and delivering a total dose of the therapy light. The method may include developing a treatment plan having the therapy light having a first wavelength, the monitoring light having a second wavelength, the predetermined fluence rate, the total dose, and executing, using computer processor, the treatment plan. The method where the treatment plan further may include a photosensitizer drug, the method may include activating the photosensitizer drug using the first wavelength. The method may include administering the photosensitizer drug to the patient. The method where the first wavelength may include a first range of 630nm-710nm and where the second wavelength may include a second range of 780nm-830nm. The method may include positioning an optical diffuser on the light delivery end and delivering the therapy light to a target area of the patient using the optical diffuser. The method where at least a portion of the monitoring light loss may include a macrobending loss. The method where the macrobending loss is caused by a bending of the light delivery fiber. The method where the monitoring light loss is substantially equal to twice a therapy light loss. The method may include filtering the therapy light from light reflected from the light delivery end. The method may include providing a robotically-assisted endoluminal system having a catheter and disposing the light delivery fiber within the catheter. Implementations of the described techniques may include hardware, a method or process, or a computer tangible medium.

[0013] In one general aspect, a robotically-assisted optical light delivery system may include a robotically controlled guided bendable catheter having a working end. The robotically-assisted optical light delivery system may also include a computer processor configured to determine a target area within a body of a patient and further configured to navigate the working end proximate the target area. The system may furthermore include a light delivery fiber having a light delivery end positioned within the robotically controlled guided bendable catheter with the light delivery end positioned proximate the working end. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.

[0014] Implementations may include one or more of the following features. A robotically- assisted optical light delivery system may include a therapy light source configured to produce a therapy light, a monitoring light source configured to produce a monitoring light, a reflectance filter positioned on the light delivery end configured to transmit the therapy light and configured to reflect the monitoring light, a first detector configured to receive the monitoring light from the monitoring light source and to output a transmitted detection signal, a second detector configured to receive the monitoring light from the reflectance filter and to output a reflected detection signal, a computer processor electrically coupled to the therapy light source, the first detector and the second detector and configured to determine a monitoring light loss between the monitoring light from the monitoring light source and the monitoring light from the reflectance filter, and a light source controller electrically coupled to the computer processor the therapy light source and configured to control the therapy light source based on the monitoring light loss. The robotically- assisted optical light delivery system may include a conveying optical fiber coupled to the light delivery fiber, an optical combiner in optical communication with the therapy light source and the monitoring light source configured to combine the therapy light and the monitoring light onto the conveying optical fiber, and a second tap coupler in optical communication with the conveying optical fiber and the first detector and configured to deliver the monitoring light from the reflectance filter to the second detector. The robotically-assisted optical light delivery system where the monitoring light loss is determined by differencing the transmitted detection signal and the reflected detection signal. The robotically-assisted optical light delivery system where the light source controller is configured to control the therapy light source to produce the therapy light at an initial therapy power level and to control the monitoring light source to produce the monitoring light at an initial monitoring power level. The robotically-assisted optical light delivery system where the light source controller is configured to control the therapy light source to produce the therapy light at an updated therapy power level based on the monitoring light loss. The robotically-assisted optical light delivery system where the updated therapy power level may include an increase of power substantially equal to twice the monitoring light loss. The robotically-assisted optical light delivery system where the updated therapy power level is configured to emit the therapy light at the light delivery end at a predetermined fluence rate. The robotically-assisted optical light delivery system where the therapy light emitted at the light delivery end is delivered to a target area of a patient. The robotically-assisted optical light delivery system where the therapy light is delivered to the target area of the patient for a predetermined period of time to deliver a total dose of the therapy light. The robotically-assisted optical light delivery system may include a treatment plan having the therapy light having a first wavelength, the monitoring light having a second wavelength, the predetermined fluence rate, the total dose, and the computer processor configured to execute the treatment plan. The robotically-assisted optical light delivery system where the treatment plan further may include a photosensitizer drug and where the first wavelength is configured to activate the photosensitizer drug. The robotically-assisted optical light delivery system where the treatment plan further may include administering the photosensitizer drug to the patient. The robotically-assisted optical light delivery system where the first wavelength may include a first range of 630nm-710nm and where the second wavelength may include a second range of 780nm-830nm. The robotically-assisted optical light delivery system where at least a portion of the monitoring light loss may include a macrobending loss. The robotically-assisted optical light delivery system where the macrobending loss is caused by a bending of robotically controlled guided bendable catheter and the light delivery fiber. The robotically-assisted optical light delivery system where the monitoring light loss is substantially equal to twice a therapy light loss. The robotically-assisted optical light delivery system may include a narrow band optical filter positioned between the second tap coupler and the second detector and configured to transmit the monitoring light and to block the therapy light. The robotically-assisted optical light delivery system may include an optical diffuser coupled to the reflectance filter. Implementations of the described techniques may include hardware, a method or process, or a computer tangible medium.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] So that the manner in which the above-recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to implementations, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical implementations of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective implementations.

[0017] Figure 1 is a side view of a PDT light delivery optical fiber in accordance with the present disclosure;

[0018] Figure 2 is a graphical representation of the reflectance of a PDT light delivery optical fiber in accordance with the present disclosure;

[0019] Figure 3 is a graphical representation of the transmission of a PDT light delivery optical fiber in accordance with the present disclosure;

[0020] Figure 4 is a schematic representation of a PDT light delivery optical fiber in accordance with the present disclosure;

[0021] Figure 5 is a schematic representation of a PDT light delivery optical fiber in accordance with the present disclosure;

[0022] Figure 6 is a schematic representation of a PDT light delivery optical fiber in accordance with the present disclosure; [0023] Figure 7 is a graphical representation of the macrobending loss of a PDT light delivery optical fiber in accordance with the present disclosure; and

[0024] Figure 8 is a schematic representation of a robotically-assisted optical light delivery system in accordance with the present disclosure.

DETAILED DESCRIPTION

[0025] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and within which are shown by way of illustration specific implementations by which the examples described herein may be practiced. It is to be understood that other implementations may be utilized and structural changes may be made without departing from the scope of the disclosure.

[0026] Robotically-assisted FNAB catheters of the prior art typically have an inner “working” channel, nominally 2mm in diameter, to allow needles and biopsy instruments to pass therethrough to a working end. Unfortunately, PDT light delivery systems of the prior art would suffer light loss under such macrobending conditions which would lead to an adverse effect on providing therapy light to the prescribed PDT light dosimetry as disclosed herein above.

[0027] As disclosed herein above, PDT light delivery systems of the prior art lose accuracy and efficacy in macrobending conditions. Such conditions can lead to significant measurement error in using prior art monitoring methods that will have an adverse effect on providing light to prescribed PDT light dosimetry. In certain situations, there is an inability to place other catheters (translucent) in the treatment area which precludes the use of prior art PDT light monitoring and dosimetry methods. In the afore disclosed emerging application of FNAB, heretofore PDT as an intraoperative procedure applied during lung cancer biopsy has been precluded due to significant macrobending on a PDT light delivery fiber. In accordance with the present disclosure, implementations can include a highly accurate PDT light delivery and monitoring system that is tolerant to significant macrobending. These implementations enable the insertion of an optical fiber into the working channel of FNAB devices to deliver PDT light. As part of the current disclosure, it has been discovered that certain patient profiles can benefit in performing PDT treatment while the catheter of an FNAB device is “on” the tumor. As will be disclosed in more detail herein after, patients fitting this profile would be prescribed and administered a photosensitizer drug prior to the FNAB procedure as part of treatment planning and patient preparation. While other intracorporeal PDT light delivery typically involves some mechanical bending of light delivery optical fibers, the FNAB could apply significantly greater levels of macrobending when fully articulated under the 180° bend near the tip of the catheter, less than a few centimeters from the working end of the catheter. The significant levels of macrobending create challenges for prior art PDT systems that are inventively solved by the systems and methods disclosed herein. In addition, the PDT systems of the present disclosure include a treatment plan for a patient that includes a photosensitizing drug having a predetermined activation wavelength; therapy light source 41 have a predetermined therapy light wavelength; a predetermined period of dosing; and a total dose to be delivered.

[0028] Implementations of the present disclosure provide systems and methods of delivering and of monitoring transmitted PDT light at the tip of a delivery optical fiber, that enables the delivery and monitoring of therapy light in a single device. With reference to FIG. 1 , there is shown a delivery optical fiber 10 comprised of an optical fiber 11 and a reflectance filter 12 positioned on the light delivery end 13 (the distal end). Light delivery end 13 can comprise an optical diffuser (not shown) positioned after reflectance filter 12. Optical fiber 11 can comprise a single mode fiber having, for example, a core diameter between 8 and 10.5 pm and a cladding diameter of 125 pm and capable of transmitting light of various wavelengths when coupled to a light source as will be disclosed in more detail herein after. Optical fiber 11 can further comprise a multi-mode fiber having a core size of 50 -200 pm and a cladding diameter of 125 to 220 pm. Reflectance filter 12 can comprise a thin-film filter that is configured to pass a wavelength of PDT light and deliver the PDT light through the light delivery end 13 of delivery optical fiber 10 and is further configured to reflect essentially all of a preselected monitoring wavelength. The monitoring wavelength is selected such that it is of a wavelength that is sufficiently out of the band of wavelength.

[0029] The wavelength of the PDT light ( _PDT) is selected to based on the activation wavelength for a particular PDT photosensitizer drug. For instance, some PDT photosensitizer drugs are activated in the 630nm-710nm range. In a particular implementation, a monitoring source, can have a monitoring wavelength (A_M0W) nominally in the near infrared range of 780-830nm. Such sources are readily available at low cost and operate with most optical fibers and fiber-based components. Referring next to FIG. 2, there is shown a graphical representation of a reflectance versus wavelength for delivery optical fiber 10 optically coupled to a wideband source. As shown in the figure, light centered about A_MO/V 20 is strongly reflected by reflectance filter 12 while light at other wavelengths is weakly reflected. The converse is also true, and with reference to FIG. 3, there is shown a graphical representation of a transmission versus wavelength for delivery optical fiber 10 optically coupled to a wideband source. As shown in the figure, very little of the light centered about A_MO/V 30 passes through reflectance filter 12 while light at other wavelengths has a high transmission rate and passes through the reflectance filter and exits the light delivery end 13 of delivery optical fiber 10. The monitoring source can also be used as a test source as will be disclosed in more detail herein after.

[0030] Referring now to FIG. 4, there is shown a schematic representation of an implementation of an optical light delivery system in the form of a PDT light delivery and monitoring system 40 including delivery optical fiber 10. PDT light delivery and monitoring system 40 includes a therapy light source in the form of PDT light source 41 , monitoring light source 42, optical combiner 43, injector 44, delivery tap coupler 45, delivery detector 46, monitoring tap coupler 47, optical filter 48, monitoring detector 49 and delivery optical fiber 10 all variously coupled in optical communication. PDT light source 41 can comprise a narrow band laser capable of producing PDT light around a preselected wavelength and in some implementations the wavelength can be around 630nm. Monitoring light source 42 can comprise a narrow band laser capable of producing a monitoring light around a preselected wavelength outside of the band of PDT light source 41 and in some implementations the wavelength can be around 780nm PDT light source 41 and monitoring light source 42 are coupled to optical combiner 43 which can comprise a combiner or other passive fiber routing device where the light of the two wavelengths are combined and then injected into a conveying optical fiber by injector 44 which can comprise a lens. Delivery tap coupler 45 can comprise a 1 x 2 multimode fiber tap coupler (95/5) where 5% of the light is routed to delivery detector 46. Delivery detector 46 is configured to monitor a power level, measured in joules (J), of the light injected into the light delivery optical fiber to produce a transmitted detection signal as will be disclosed in more detail herein after. The remainder of the light (95%), which includes PDT light and monitoring light, travels through the through leg of delivery detector 46 and is delivered to monitoring detector 49 wherein 100% of that light is delivered to optical fiber 11 of delivery optical fiber 10. the input port is then spliced to the PDT light delivery fiber device. Monitoring light and PDT light (with the exception of the portion directed to delivery detector 46) is launched into delivery optical fiber 10 and transmitted to reflectance filter 12. The PDT light having a wavelength _PDT, in this example of nominally 630nm, passes through reflectance filter 12 and is emitted through light delivery end 13 to deliver the therapy light to a target area or target tissue within the body of a patient at a predetermined fluence rate measured in milli-watts per square centimeter (mW /cm²). The monitoring light having a wavelength A_M0W, in this example of nominally 780nm, laser is strongly reflected by reflectance filter 12. The reflected monitoring light is then routed back to monitor tap coupler 47 which comprises a 1 x 2 tap coupler wherein the tap port is optically coupled to monitor detector 49 and the monitor detector receives 100% of the reflected monitoring light. Monitor detector 49 produces a reflected detection signal proportional to the intensity of the reflected monitoring light. The reflected monitoring light can be filtered by optical filter 48 which can comprise a narrow band optical filter having the opposite transmission/reflection characteristics of reflectance filter 12. Optical filter 48 positioned before the detector is configured to collect only reflected monitoring light and to reject any backscattered or reflected PDT light.

[0031] Still referring to FIG. 4, PDT light delivery and monitoring system 40 can be used to calibrate delivery optical fiber 10. Certain implementations of PDT light delivery and monitoring system 40 include a computer processor electrically coupled to a light source controller, source detector 46 and monitor detector 49 to monitor, control and calibrate the system. In the operation of calibrating delivery optical fiber 10, the delivery optical fiber is positioned in a straight, unperturbed configuration as shown. A user can set the monitoring light source 42 to a known power setting. The power level measured at monitor detector 49 takes into account all of the optical losses through out the various components of PDT light delivery and monitoring system 40 and can be used to determine any microbend induced losses as will be disclosed herein after. Referring to FIG.5, there is shown a graphical representation intensity versus wavelength for A_MO/V of the reflected monitoring light received by monitor detector 49 during the calibration procedure. The initial monitoring power level is shown as peak power intensity level 50 measured at the wavelength of the monitoring light A_MO/V is recorded for PDT light delivery and monitoring system 40 while the system is in the straight, unperturbed configuration as shown in FIG. 4. One skilled in the art that there is a corresponding therapy light loss and an initial therapy power level as well. Referring next to FIG. 6, PDT light delivery and monitoring system 40 is shown in schematic form with delivery optical fiber 10 in a u-bend position replicating an interoperative position of the delivery optical fiber. In many cases the in- situ interoperative bending of delivery optical fiber 10 can be known from imaging and programming techniques. As disclosed herein above, the u-bend position of delivery optical fiber 10 manifests in macrobend losses that affect both the PDT light and monitoring light. In the u-bend position the monitoring light is reflected back and monitored using monitor detector 49 to provide a measurement of the loss accumulated over the delivery optical fiber 10. With reference to FIG. 7, the measured peak 70 received by monitor detector 49 at the wavelength of the monitoring light A_MO/V shows the monitoring light loss 71 of intensity due to macrobending delivery optical fiber 10. Monitoring light loss 71 can then be compared or integrated with the launch power monitoring as measured at delivery detector 46 to adjust the power PDT light source 41 to an updated therapy power level and monitoring light source 42, amounting to an increase in power to overcome the losses, accordingly to deliver a prescribed amount of PDT light. It should be appreciated by those skilled in the art that that monitoring loss 71 is substantially twice the intensity due to macrobending of the light delivery fiber device because it travels through the light path twice. The monitoring light travels from monitor tap coupler 47 along optical fiber 11 , reflects off of reflectance filter 12, travels back along optical fiber 11 through the monitor tap coupler, through optical filter 48 and becomes incident on monitor detector 49. It should be noted that PDT light delivery and monitoring system 40 can be calibrated for all losses and that the adjustment of the therapy light can be similarly calibrated prior to use. In addition, during a PDT procedure, the monitoring light is reflected back and monitored using monitor detector 49 to provide a measurement of the loss accumulated over the delivery optical fiber 10 and the intensity of the therapy light and/or the duration of the delivery of the therapy light can be adjusted to accomplish the prescribed PDT light dosimetry.

[0032] There are other optical routing arrangements and signal processing/control loop circuits contemplated by the current disclosure. It should be appreciated by those skilled in the art that PDT light delivery and monitoring system 40 inventively provides for macrobend loss monitoring completely over the entire delivery optical fiber 10 to the very distal end at light delivery end 13. Such monitoring and adjustment capability advantageously enables the aforementioned robotically controlled guided bendable catheter applications where tight (180° for example) bends and resulting significant macrobend attenuation are anticipated.

[0033] Robotically-assisted optical light delivery systems including PDT light delivery and monitoring system 40 inventively enables other PDT applications, such as interstitial PDT, where PDT light can be delivered through needle catheters, with limited space to provide light delivery monitoring fibers of detection components. Referring next to FIG. 8, there is shown a robotically-assisted optical light delivery system 80 utilizing aspects of the present disclosure. The robotically-assisted optical light delivery system 80 includes a catheter system 81 coupled by an interface unit 88 to a tracking system 87. A navigation system 89 processes information from a virtual visualization system 90, one or more imaging systems 91 , and/or the tracking system 87 to generate one or more image displays on a display system 92 and PDT light delivery and monitoring system 40.

[0034] The catheter system 81 includes an elongated flexible body 86 having a proximal end 93 and a distal end 84. A channel 94 extends within the flexible body 86. In one embodiment, the flexible body 86 has an approximately 3 mm outer diameter. Other flexible body outer diameters may be larger or smaller. The catheter system 81 optionally includes a sensor system which includes a position sensor system 82 (e.g., an electromagnetic (EM) sensor system) and/or a shape sensor system 83 for determining the position, orientation, speed, pose, and/or shape of the catheter tip at distal end 84 and/or of one or more segments 85 along the body 86. The position sensor system 82 and the shape sensor system 83 interface with the tracking system 87. The tracking system 87 may be implemented as hardware, firmware, software or a combination thereof which interact with or are otherwise executed by one or more computer processors, which may include the afore disclosed processor. The shape sensor system 83 can be a bend sensor for determining the shape of the catheter system 81 .

[0035] The tracking system 87 may include a detection system for generating and detecting signals for determining the shape of the catheter system 81. This information, in turn, in can be used to determine other related variables, such as velocity and acceleration of the parts of a robotically-assisted optical light delivery system 80. The sensing may be limited only to the degrees of freedom that are actuated by the robotically- assisted optical light delivery system 80.

[0036] As shown, flexible body 86 houses delivery optical fiber 10 comprised of an optical fiber 11 wherein reflectance filter 12 and light delivery end 13 exit distal end 84. As disclosed herein above, light delivery end 13 delivers therapy light to an area of interest of a patient by robotically-assisted optical light delivery system 80. [0037] The body 86 may also house cables, linkages, or other steering controls (not shown) that extend between the interface 88 and the tip distal end 84 to controllably bend or turn the distal end 84 as shown for example by the dotted line versions of the distal end. It is in these controllable bends that the macrobend losses disclosed herein above occur. The catheter system may be steerable or, alternatively, may be non-steerable with no integrated mechanism for operator control of the instrument bending. The flexible body 86 may further house control mechanisms (not shown) for manipulating the position of light delivery end 13, e.g., for effecting a predetermined treatment of a target tissue.

[0038] All of the implementations disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the apparatus and methods of this disclosure have been described in terms of preferred implementations, it will be apparent to those of skill in the art that variations may be applied to the methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the disclosure. In addition, modifications may be made to the disclosed apparatus and components may be eliminated or substituted for the components described herein where the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope, and concept of the disclosure.

[0039] Although the disclosure(s) is/are described herein with reference to specific implementations, various modifications and changes can be made without departing from the scope of the present disclosure(s), as presently set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present disclosure(s). Any benefits, advantages, or solutions to problems that are described herein with regard to specific implementations are not intended to be construed as a critical, required, or essential feature or element of any or all the claims. [0040] Unless stated otherwise, terms such as "first" and "second" are used to arbitrarily distinguish between the elements such terms describe. Thus, these terms are not necessarily intended to indicate temporal or other prioritization of such elements. The terms "coupled" or "operably coupled" are defined as connected, although not necessarily directly, and not necessarily mechanically. The terms "a" and "an" are defined as one or more unless stated other The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more elements possesses those one or more elements but is not limited to possessing only those one or more elements. Similarly, a method or process that “comprises,” “has,” “includes” or “contains” one or more operations possesses those one or more operations but is not limited to possessing only those one or more operations.

[0041] While the foregoing is directed to implementations of the present disclosure, other and further implementations of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

WHAT IS CLAIMED IS: CLAIMS

1 . An optical light delivery system comprising: a therapy light source configured to produce a therapy light; a monitoring light source configured to produce a monitoring light; a light delivery fiber having a light delivery end; a reflectance filter positioned on the light delivery end configured to transmit the therapy light and configured to reflect the monitoring light; a first detector configured to receive the monitoring light from the monitoring light source and to output a transmitted detection signal; a second detector configured to receive the monitoring light from the reflectance filter and to output a reflected detection signal; a computer processor electrically coupled to the therapy light source, the first detector and the second detector and configured to determine a monitoring light loss between the monitoring light from the monitoring light source and the monitoring light from the reflectance filter; and a light source controller electrically coupled to the computer processor the therapy light source and configured to control the therapy light source based on the monitoring light loss.

2. The optical light delivery system of claim 1 further comprising: a conveying optical fiber coupled to the light delivery fiber; an optical combiner in optical communication with the therapy light source and the monitoring light source configured to combine the therapy light and the monitoring light onto the conveying optical fiber; and a second tap coupler in optical communication with the conveying optical fiber and the first detector and configured to deliver the monitoring light from the reflectance filter to the second detector. The optical light delivery system of claim 2 wherein the monitoring light loss is determined by differencing the transmitted detection signal and the reflected detection signal. The optical light delivery system of claim 3 wherein the light source controller is configured to control the therapy light source to produce the therapy light at an initial therapy power level and to control the monitoring light source to produce the monitoring light at an initial monitoring power level. The optical light delivery system of claim 4 wherein the light source controller is configured to control the therapy light source to produce the therapy light at an updated therapy power level based on the monitoring light loss. The optical light delivery system of claim 5 wherein the updated therapy power level comprises an increase of power substantially equal to twice the monitoring light loss. The optical light delivery system of claim 5 wherein the updated therapy power level is configured to emit the therapy light at the light delivery end at a predetermined fluence rate. The optical light delivery system of claim 7 wherein the therapy light emitted at the light delivery end is delivered to a target area of a patient. The optical light delivery system of claim 8 wherein the therapy light is delivered to the target area of the patient for a predetermined period of time to deliver a total dose of the therapy light. The optical light delivery system of claim 9 further comprising a treatment plan comprising: the therapy light comprising a first wavelength; the monitoring light comprising a second wavelength; the predetermined fluence rate; the total dose; and the computer processor configured to execute the treatment plan. The optical light delivery system of claim 10 wherein the treatment plan further comprises a photosensitizer drug and wherein the first wavelength is configured to activate the photosensitizer drug. The optical light delivery system of claim 11 wherein the treatment plan further comprises administering the photosensitizer drug to the patient. The optical light delivery system of claim 10 wherein the first wavelength comprises a first range of 630nm-710nm and wherein the second wavelength comprises a second range of 780nm-830nm. The optical light delivery system of claim 5 wherein at least a portion of the monitoring light loss comprises a macrobending loss. The optical light delivery system of claim 14 wherein the macrobending loss is caused by a bending of the light delivery fiber. The optical light delivery system of claim 14 wherein the monitoring light loss is substantially equal to twice a therapy light loss. The optical light delivery system of claim 2 further comprising a narrow band optical filter positioned between the second tap coupler and the second detector and configured to transmit the monitoring light and to block the therapy light. The optical light delivery system of claim 1 further comprising a robotically- assisted endoluminal system having a catheter and wherein the light delivery fiber is disposed within the catheter. The optical light delivery system of claim 1 further comprising an optical diffuser coupled to the reflectance filter. An method of delivering therapy light to a patient comprising: producing a therapy light; producing a monitoring light; providing a light delivery fiber having a light delivery end; combining the therapy light and the monitoring light; delivering the therapy light and the monitoring light; reflecting the monitoring light from the light delivery end; transmitting the therapy light from the light delivery end; monitoring the monitoring light and outputting a transmitted detection signal; monitoring the monitoring light reflected from the light delivery end and outputting a reflected detection signal; determining, using a computer processor, a monitoring light loss between the transmitted detection signal and the reflected detection signal; and controlling, using the computer processor and a light source controller, producing the therapy light based on the monitoring light loss. The method of delivering therapy light to a patient of claim 20 wherein determining the monitoring light loss comprises differencing the transmitted detection signal and the reflected detection signal. The method of delivering therapy light to a patient of claim 21 wherein producing the therapy light comprises an initial therapy power level and producing the monitoring light comprises an initial monitoring power level. The method of delivering therapy light to a patient of claim 22 further comprising determining, using the computer processor, an updated therapy power level based on the monitoring light loss and controlling producing the therapy light using the updated therapy power level. The method of delivering therapy light to a patient of claim 23 wherein the updated therapy power level comprises an increase of power substantially equal to twice the monitoring light loss. The method of delivering therapy light to a patient of claim 23 further comprising emitting the therapy light at the updated therapy power level at the light delivery end and at a predetermined fluence rate. The method of delivering therapy light to a patient of claim 25 further comprising delivering the therapy light emitted at the light delivery end to a target area of the patient. The method of delivering therapy light to a patient of claim 26 wherein the delivering the therapy light comprised delivering the therapy light to the target area of the patient for a predetermined period of time and delivering a total dose of the therapy light. The method of delivering therapy light to a patient of claim 27 further comprising: developing a treatment plan comprising: the therapy light comprising a first wavelength; the monitoring light comprising a second wavelength; the predetermined fluence rate; the total dose; and executing, using computer processor, the treatment plan. The method of delivering therapy light to a patient of claim 28 wherein the treatment plan further comprises a photosensitizer drug, the method further comprising activating the photosensitizer drug using the first wavelength. The method of delivering therapy light to a patient of claim 29 further comprising administering the photosensitizer drug to the patient. The method of delivering therapy light to a patient of claim 28 wherein the first wavelength comprises a first range of 630nm-710nm and wherein the second wavelength comprises a second range of 780nm-830nm. The method of delivering therapy light to a patient of claim 25 wherein at least a portion of the monitoring light loss comprises a macrobending loss. The method of delivering therapy light to a patient of claim 32 wherein the macrobending loss is caused by a bending of the light delivery fiber. The method of delivering therapy light to a patient of claim 32 wherein the monitoring light loss is substantially equal to twice a therapy light loss. The method of delivering therapy light to a patient of claim 20 further comprising filtering the therapy light from light reflected from the light delivery end. The method of delivering therapy light to a patient of claim 20 further comprising providing a robotically-assisted endoluminal system having a catheter and disposing the light delivery fiber within the catheter. The method of delivering therapy light to a patient of claim 26 further comprising positioning an optical diffuser on the light delivery end and delivering the therapy light to a target area of the patient using the optical diffuser. A robotically-assisted optical light delivery system comprising: a robotically controlled guided bendable catheter having a working end; a computer processor configured to determine a target area within a body of a patient and further configured to navigate the working end proximate the target area; and a light delivery fiber having a light delivery end positioned within the robotically controlled guided bendable catheter with the light delivery end positioned proximate the working end. The robotically-assisted optical light delivery system of claim 38 further comprising: a therapy light source configured to produce a therapy light; a monitoring light source configured to produce a monitoring light; a reflectance filter positioned on the light delivery end configured to transmit the therapy light and configured to reflect the monitoring light; a first detector configured to receive the monitoring light from the monitoring light source and to output a transmitted detection signal; a second detector configured to receive the monitoring light from the reflectance filter and to output a reflected detection signal; a computer processor electrically coupled to the therapy light source, the first detector and the second detector and configured to determine a monitoring light loss between the monitoring light from the monitoring light source and the monitoring light from the reflectance filter; and a light source controller electrically coupled to the computer processor the therapy light source and configured to control the therapy light source based on the monitoring light loss. The robotically-assisted optical light delivery system of claim 39 further comprising: a conveying optical fiber coupled to the light delivery fiber; an optical combiner in optical communication with the therapy light source and the monitoring light source configured to combine the therapy light and the monitoring light onto the conveying optical fiber; and a second tap coupler in optical communication with the conveying optical fiber and the first detector and configured to deliver the monitoring light from the reflectance filter to the second detector. The robotically-assisted optical light delivery system of claim 40 wherein the monitoring light loss is determined by differencing the transmitted detection signal and the reflected detection signal. The robotically-assisted optical light delivery system of claim 41 wherein the light source controller is configured to control the therapy light source to produce the therapy light at an initial therapy power level and to control the monitoring light source to produce the monitoring light at an initial monitoring power level. The robotically-assisted optical light delivery system of claim 42 wherein the light source controller is configured to control the therapy light source to produce the therapy light at an updated therapy power level based on the monitoring light loss. The robotically-assisted optical light delivery system of claim 43 wherein the updated therapy power level comprises an increase of power substantially equal to twice the monitoring light loss. The robotically-assisted optical light delivery system of claim 43 wherein the updated therapy power level is configured to emit the therapy light at the light delivery end at a predetermined fluence rate. The robotically-assisted optical light delivery system of claim 45 wherein the therapy light emitted at the light delivery end is delivered to a target area of a patient. The robotically-assisted optical light delivery system of claim 46 wherein the therapy light is delivered to the target area of the patient for a predetermined period of time to deliver a total dose of the therapy light. The robotically-assisted optical light delivery system of claim 47 further comprising a treatment plan comprising: the therapy light comprising a first wavelength; the monitoring light comprising a second wavelength; the predetermined fluence rate; the total dose; and the computer processor configured to execute the treatment plan. The robotically-assisted optical light delivery system of claim 48 wherein the treatment plan further comprises a photosensitizer drug and wherein the first wavelength is configured to activate the photosensitizer drug. The robotically-assisted optical light delivery system of claim 49 wherein the treatment plan further comprises administering the photosensitizer drug to the patient. The robotically-assisted optical light delivery system of claim 48 wherein the first wavelength comprises a first range of 630nm-710nm and wherein the second wavelength comprises a second range of 780nm-830nm. The robotically-assisted optical light delivery system of claim 43 wherein at least a portion of the monitoring light loss comprises a macrobending loss. The robotically-assisted optical light delivery system of claim 52 wherein the macrobending loss is caused by a bending of robotically controlled guided bendable catheter and the light delivery fiber. The robotically-assisted optical light delivery system of claim 52 wherein the monitoring light loss is substantially equal to twice a therapy light loss. The robotically-assisted optical light delivery system of claim 40 further comprising a narrow band optical filter positioned between the second tap coupler and the second detector and configured to transmit the monitoring light and to block the therapy light. The robotically-assisted optical light delivery system of claim 39 further comprising an optical diffuser coupled to the reflectance filter.