Patent Application
20210299465
The present disclosure relates generally to delivery of therapeutic energy and, more particularly, to systems and methods that deliver energy to a target region of a patient's body (of arbitrary shape and/or size) to precisely satisfy therapeutic requirements.
Types of energy, like optical energy, are increasingly used to treat a wide variety of medical conditions. For example, the U.S. Food and Drug Administration (FDA) has approved the use of optical energy to treat cancer and other similar conditions, relieve pain due to musculoskeletal disorders and autoimmune disorders, perform cosmetic procedures, and the like. However, optical energy has not been widely employed for certain applications requiring energy delivery because the delivery of the optical energy is time consuming, expensive, and not particularly precise.
According to the present disclosure, an energy beam is manipulated and scanned to fill a treatment region of any size or shape to precisely, specifically, and rapidly deliver a required dose and/or fluence.
In one aspect, the present disclosure can include a system that delivers a dose profile and/or a fluence profile to a target region of a patient's body of a shape or a size. The system includes a beam-path determination unit configured to define a path and duration for an energy beam to deliver a dose and/or a fluence of energy to the target region of the patient's body of the shape and/or the size. The system also includes an energy delivery system comprising an energy source and director device, coupled to the beam-path determination unit. The energy source is configured to project the energy beam for the duration. The director device is configured to direct the energy beam along the path to deliver the dose and/or the fluence to the target region of the patient's body to achieve the dose profile and/or the fluence profile.
In another aspect, the present disclosure can include a method for delivering a dose profile and/or a fluence profile to a target region of a patient's body of a shape or a size. The method includes defining, by a beam path determination unit, a path and a duration for an energy beam to deliver a dose and/or a fluence of energy to a target region of a patient's body of a shape and/or a size. The method also includes projecting, by an energy source of an energy delivery system, the energy beam for the duration; and directing, by a director device of the energy delivery system, the energy beam along the path to deliver the dose and/or the fluence to the target region of the patient's body to achieve the dose profile and/or the fluence profile.
In a further aspect, the present disclosure can include a system that delivers a precisely contoured dose profile and/or fluence profile to a target region of a patient's body of a shape or a size. The system includes a beam-path determination unit configured to define a scan pattern for the target region comprising one or more paths for an electromagnetic beam and to configure parameters of the electromagnetic beam. The parameters can include at least one of beam size, scan rate, separation distance and/or overlap of sequential paths, and a number of path repetitions. The system also includes an energy delivery system comprising an energy source and director device, coupled to the beam-path determination unit. The energy source is configured to project the electromagnetic beam with the parameters. The director device is configured to direct the electromagnetic beam along the scan pattern to accumulate energy in the target region.
The foregoing and other features of the present disclosure will become apparent to those skilled in the art to which the present disclosure relates upon reading the following description with reference to the accompanying drawings, in which:
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which the present disclosure pertains.
In the context of the present disclosure, the singular forms “a,” “an” and “the” can also include the plural forms, unless the context clearly indicates otherwise.
The terms “comprises” and/or “comprising,” as used herein, can specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups.
As used herein, the term “and/or” can include any and all combinations of one or more of the associated listed items.
Additionally, although the terms “first,” “second,” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, a “first” element discussed below could also be termed a “second” element without departing from the teachings of the present disclosure.
As used herein, the term “energy” can be used to represent radiant energy that travels by waves or particles, particularly electromagnetic radiation (visible and/or invisible). Energy that is used in connection with light (a type of electromagnetic radiation) can be referred to as optical energy. “Energy beams,” “electromagnetic beams,” “optical beams,” and the like as used herein can refer to radiant energy that travels by waves or particles and that remains essentially concentrated around a mean axis upon free propagation or that is guided by suitable structures such as lenses or reflectors.
As used herein, the term “energy source” can refer to something that can be configured to provide/generate an energy beam. In the case of optical energy, the energy source can include, for example, at least one laser and/or light source and can be configured to permit spectral adjustment and/or spectral modulation of the energy beam.
As used herein, the term “energy beam” can refer to energy being sent in a direction. The energy beam can be pulsed and/or continuous. The energy beam can be projected with a shape (circle, rectangle, square, hexagon, triangle, etc.) and/or a size. Additionally, the energy beam can be collimated, diverging, converging, or have a focal length. The energy beam can be of any beam profile type. In some instances, the energy beam can possess a Gaussian intensity profile or the energy beam can possess a non-Gaussian intensity profile.
As used herein, the term “dose” can refer to the total energy delivered to a target region. Delivery of energy to a patient can have certain dose requirements. In some instances, the term dose can include dosage (dose per unit area).
As used herein, the term “dose profile” can refer to the 2D or 3D pattern of accumulated dose within a target region, after treatment is completed. The “dose profile” can also refer to the pattern of dose occurring along or to the sides of a specified path of a beam, and to a specified depth, as the beam scans within the target region.
As used herein, the term “fluence” can refer to the energy that passes through a surface area of a target region. Delivery of energy to a patient can have certain fluence requirements.
As used herein, the term “fluence profile” can refer to the 2D or 3D pattern of accumulated fluence within a target region, after treatment is completed. The “fluence profile” can also refer to the pattern of fluence occurring along or to the sides of a specified path of a beam, and to a specified depth, as the beam scans within the target region.
As used herein, the term “delivery characteristic” can refer to one or more properties of the energy beam. The delivery characteristic can be based on the dose profile and/or the fluence profile and can be variable along the path. For example, the delivery characteristic can include a beam scan rate, a beam path repetition number, a number of repetitions of an area of the path, a beam power, a beam power modulation pattern and/or rate, a beam size, a beam collimation, divergence, convergence, or focus, a beam intensity profile, a beam shape, or the like.
As used herein, the term “target region” can refer to a portion of a patient's body of an arbitrary shape and/or size to be treated with energy. The target region can include an area, a surface area, a volume, or the like. In certain examples, the target region can be large and/or complex.
As used herein, the term “path” can refer to a pattern in space along which the energy beam is translated. The path may be continuous or discontinuous. A discontinuous path comprises two or more sub-paths that are separated in space from each other. In some instances, the path can include one or more guides, in, on, near, or surrounding the patient, for the energy beam. In some instances, the path can include a marking in, on, or below the patient's skin (e.g., a drawing, an outline, a fiducial marker, or the like).
As used herein, the term “duration” can refer to a time the target region is exposed to the energy. In some instances, different portions of the target region can be exposed to the energy for different times.
As used herein, the terms “subject” and “patient” can be used interchangeably and refer to any warm-blooded organism including, but not limited to, a human being, a pig, a rat, a mouse, a dog, a cat, a goat, a sheep, a horse, a monkey, an ape, a rabbit, a cow, etc.
The present disclosure describes the delivery of energy to a treatment region of a patient's body (a line, a curve, an area, surface area, and/or volume of arbitrary shape or size) to precisely satisfy therapeutic dose requirements and/or fluence requirements. A clinical outcome is usually sensitive to both dose and fluence (such that fluence levels that are too high can be acutely dangerous, while fluence levels that are too low might reside below a threshold for effectiveness, if such a threshold exists). The present disclosure empowers clinicians and other medical professionals to precisely achieve a required total dose and/or a required average, minimum, or maximum fluence over the entire treatment region (however large or irregularly shaped that region may be). Advantageously, the energy can be delivered to the area or volume of the patient's body without requiring a large and expensive energy source. Systems and methods described herein employ a beam, of smaller dimensions than the treatment region itself, to scan over a path through the treatment region. Other factors that impact efficacy and safety, such as the following, may also be precisely controlled within the treatment region: the dose profile and/or fluence profile; certain important dynamic parameters, such as the scan rate, path repetition rate, power modulation rate and the temporal modulation shape (cw, step function, saw-tooth curve, etc.); spectral content of the beam; and treatment depth. In other words, an energy profile in time, space, and wavelength may be precisely delivered.
The system 20 can combine advantages of pulsed-light with precise large-area/surface area/volume irradiation by scanning a projected energy beam over a precise path. As such, moving the energy beam can be equivalent to pulsing a stationary energy beam in the sense that a particular portion of the patient's body sees the beam for a period of time (which may be brief) and then the beam moves to the next location. Each irradiated location along the path experiences an ON and OFF time. For scans that repeat (over at least a portion of the path), each irradiated location that repeats can experience a sequence of ON and OFF times. Dose and/or fluence can be controlled by adjusting one or more delivery characteristics, including beam intensity, beam dimensions, beam size, beam shape, number of beams, beam modulation, scan rate, path length/shape, path overlap, number of repetitions, or the like. In some instances, the delivery characteristic can be varied along the path.
As shown in
The beam path determination unit 22 can instruct the energy delivery system 24 of the path and duration to deliver the energy beam. For example, the beam path determination unit 22 can send instructions regarding the path and/or duration to the energy delivery system 24. The energy delivery system 24 can include at least an energy source 26 and a director device 28. The energy source 26 can deliver an energy beam (which may have a focal length that can vary along the path) of a projected shape (a circle, a square, a rectangle, a triangle, a hexagon, or the like) and a projected size. The energy source 26 can include one or more sources that are configured to project at least a portion of the energy beam (in some instances, the portions of the energy beam can differ in wavelength, frequency, spectral content, or the like). For example, the one or more sources can be lasers, laser diodes, light emitting diodes, and/or other types of light sources. The energy beam can be continuous (cw) and/or pulsed and can be subject to spectral adjustment and/or spectral modulation. The director device 28 can be configured to direct the energy beam along the path defined by the beam path determination unit 22.
An example path can be determined by the system of
Because the beam is scanned (moving relative to the target region), certain bio-dynamic phenomena that are power- and time-sensitive (such as self-cooling by blood perfusion, photo-bleaching of tissue, chemical and electrical transport within neuronal networks, protein interactions in endosome trafficking, transient absorption and energy transport within and between sub-cellular structures, and the like) may be specifically addressed to improve the efficiency and/or efficacy of the procedure.
The rate at which the beam is scanned can also serve as a precisely selective therapeutic parameter: ensuring interaction with some biological features and remaining “invisible” to others. This is possible because certain biological processes have “time constants” of their own: some processes respond very quickly to energy stimulation and others much more slowly. So that in some cases, a beam can pass so quickly over a treatment region that only certain “fast” or “ultra-fast” biological functions are able to respond, while for other slower processes it is as if the beam was never present at all. In this way, this invention provides a means for providing therapeutic specificity to large and/or complex target regions. Thus the scan rate of this invention can be used to prevent and/or avoid certain slower biological and physical processes (such as heat transfer and thermal damage) while targeting certain faster processes (such as mitochondrial absorption).
For example, because the dwell time of a rapidly scanned beam of this invention can be very short, higher power lasers (which, in certain deep tissue applications, have greater penetration depths than low power energy sources) may be used to treat internal tissues without traumatizing the overlying tissue. If too much energy is put into a region of bodily tissue, the bodily tissue can be heated up and damaged. However, given enough time, the blood flowing through living tissue that has been heated can dissipate heat before additional heat is added to damaging levels. Therefore, powerful energy beams can be delivered into tissue without damaging the tissue if the beam is translated rapidly over the treatment region so as to achieve a dwell time that is therapeutically significant but thermally safe. A rapidly scanned beam can be thought of as being equivalent to a stationary beam that is pulsed ON briefly and then left OFF long enough for blood perfusion to dissipate the heat. Notice however, that unlike a stationary beam, the scanned beam of this invention moves to another location within the treatment region while the previously treated tissue is given sufficient time to normalize after its brief period of irradiation. Furthermore, after each targeted portion of the treatment region has been treated safely and momentarily, the scanning beam can be directed to return again and again to the same locations to effect a total accumulated dose that satisfies the therapeutic endpoint. In this manner, large and complex target regions can be rapidly treated using a powerful beam without adverse effects in any portion of the tissue.
As noted, the translation of the scanning energy beam of this invention results in the intermittent irradiation of a bodily target region. Thus, even though the energy source may be operated in cw, or continuous wave, mode, the target region experiences intermittent or pulsed exposure. This invention therefore can be used to impart bio-dynamic and photo-dynamic specificity to the therapy even when the energy beam is always or mostly ON. In addition to the clinical advantages described above, this can provide economic advantages because CW operation of lasers, laser diodes, light emitting diodes, incandescent light sources, and the like, can be a simple and cost-effective source of energy. However, pulsed energy sources are also entirely compatible with this invention. While the energy beam is translated it may also be pulsed, or time modulated. Time modulation, wherein the energy source or the projected beam is repeatedly turned ON and OFF or modulated so that the beam power follows a square wave, or sine wave, or triangular wave or the like, when used in combination with beam translation, imparts additional degrees of freedom to the therapy which are otherwise unavailable. For example, by scanning and simultaneously pulsing the beam, targeted tissue can be exposed to energy for ultra-short durations which might not be achievable by scanning or pulsing alone.
Another aspect of the present disclosure can include a method 30 (
The method 30 is illustrated as a process flow diagram with flowchart illustrations. For purposes of simplicity, the method 30 shown is and described as being executed serially; however, it is to be understood and appreciated that the present disclosure is not limited by the illustrated order as some steps could occur in different orders and/or concurrently with other steps shown and described herein. Moreover, not all illustrated aspects may be required to implement the method 30.
At 32, a path and a duration (which may vary for different parts of the path) for an energy beam to irradiate a target region of a patient's body can be defined (e.g., by beam path determination unit 22) and parameters can be selected to deliver a dose/fluence (or dose/fluence profile) of energy to a target region of a patient's body (which may be an area, a surface area, and/or a volume). The path and the duration can be defined to satisfy a dose profile and/or a fluence profile (which can be defined during and/or prior to the projection of the beam and/or adjusted during projection of the beam). The defining or adjusting can be based on at least one measurable parameter related to efficacy and/or safety. In some instances, a marked path on the patient's skin (e.g., a fiducial marker, a marking drawn on the patient's skin, etc.) can be tracked to determine the path. In other instances, the beam path can be defined based on a two dimensional (2D) or three dimensional (3D) image of the patient's internal anatomy. In yet other instances, the beam path can be defined or adjusted based on markings or markers or transponders located in, on, or near the patient.
At 34, the energy beam can be projected (e.g., by energy source 26 of energy delivery system 24) for the duration. The dose can be controlled by adjusting a scan rate, a number of repetitions, etc. For example, the energy beam can be projected as a continuous wave (cw) beam, a scanned beam, and/or a pulsed beam. The energy beam can be of a projected shape (a circle, a square, a rectangle, a hexagon, a triangle, or the like) and/or a projected size. The energy beam can be collimated, diverging, converging, focused, diffuse, substantially uniform, and/or Gaussian in profile. At 36, the energy beam can be directed along the path (e.g., by director device 28 of energy delivery system 24) to deliver the dose/fluence (or dose/fluence profile) to the target region of the patient's body. In other words, the energy beam can be scanned (e.g., as a raster scan) along the portions of the path for the duration.
Some applications for energy delivery may be directed at skin treatments, which primarily involve the superficial delivery of a therapeutic dosage of energy. In the case of a skin treatment, the treatment region is a surface area. Other applications for energy delivery may require the delivery of a therapeutic dose to organs below the surface of the skin, in which case the treatment region is a volume. It will be understood that when energy is delivered through the skin to underlying tissues, some portion of that energy will be scattered, absorbed, and generally attenuated by the skin and by other intervening tissues. Furthermore, if the beam power is increased to compensate for attenuation, potential skin damage poses an upper limit on beam power.
The beam is translated with a speed (distance/time) and direction across the treatment region. This translation rate has a direct bearing on any treatment parameters that include a time factor, such as irradiance (amount of energy that passes through a unit surface area of the target region per unit time). For example, if a beam operating at a given power level is translated at a Rate A across the treatment surface wherein Rate A is faster than Rate B, then the resulting average irradiance for Rate A will be less than that of Rate B. In addition, because the dwell time of a translated beam on a patient's skin is reduced relative to that of a stationary beam, excessive accumulation of heat during treatment can be prevented. After the translating beam leaves a sub-region of the treatment region, natural heat transport processes, such as blood perfusion, will dissipate any excess heat before the beam is returned to that sub-region for any additional scans. The dissipation of heat by the patient's body is an important safety consideration during photo-treatment. Therefore, beam translation speed provides a means of delivering high powers while simultaneously protecting a patient's skin during treatment. It also remains true that if the beam is translated across the treatment surface at a Power Level A that is half the value of a Power Level B, then the resulting Irradiance for the beam moving at Rate A with Power Level A will be half that of the beam moving at Rate A with Power Level B.
Furthermore, the translating beam may be collimated, diverging, converging, or specifically focused relative to the treatment region. These parameters need not be fixed; they may be changed while the beam is translated as might be required to optimize the intended treatment, for example, for a target region that varies in depth. The translating beam may be continuously ON (cw) and/or modulated (square wave, sinusoidal, etc.) as it is translated along the treatment path. These and other parameters of beam control including spectral content, number of beams, angle of incidence, etc. may all be applied to the beam so as to optimize and adjust the quality of treatment.
This disclosure enables delivery of precise dose, fluence, and irradiance levels to regions that are clinically large and/or complex.
Determination of the beam translation path is made in accordance with the shape and size of the region to be treated, the desired degree of dose uniformity to be achieved, and the desired resolution or sharpness of the delivered dose region. As an example, a clinician may wish to apply photo-treatment to the thyroid of a patient. A preliminary radionuclide scan of the thyroid is acquired using standard lab techniques (
It should be noted that any well-known or developing method(s) can be used for the scanning of energy beams (e.g., galvanometric, acousto-optic, flat-bed translation, dynamic lenses, phasing of multi-element arrays, etc.). Thus, very large treatment regions, spanning any portion of the human body and focused to any depth within the body, may be addressed.
From the above description, those skilled in the art will perceive improvements, changes and modifications. Such improvements, changes, and modifications are within the skill of one in the art and are intended to be covered by the appended claims.
This application claims the benefit of U.S. Provisional Application No. 62/716,449, entitled “SCANNED-BEAM LIGHT THERAPY,” filed Aug. 9, 2018. The entirety of this application is hereby incorporated by reference for all purposes.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2019/045945 | 8/9/2019 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62716449 | Aug 2018 | US |
