TRANSORBITAL NIR LIGHT THERAPY DEVICE
A device for treating the brain includes a light source configured to emit near infrared light. The device also includes a collimator configured to receive the near infrared light emitted by the light emitter. The collimator is further configured to collimate the near infrared light. The device also includes an optic configured to focus collimated light. A reflector of the device is configured to change a direction of the collimated light. The reflector is at a distal end of the device, and the distal end is configured to fit between an upper portion of an eyelid of a patient and an orbital socket of the patient.
This application is a continuation of (a) U.S. patent application Ser. No. 16/732,255, filed Dec. 31, 2019, entitled “Transorbital NIR Light Therapy Device,” which claims priority to (b) U.S. Provisional Application No. 62/834,394, filed on Apr. 15, 2019, entitled “Transorbital NIR Light Therapy Devices,” (c) U.S. Provisional Application No. 62/844,855, filed May 8, 2019, entitled “Transorbital NIR Light Therapy Devices,” (d) U.S. Provisional Application No. 62/859,971, filed on Jun. 11, 2019, entitled “Transorbital NIR Light Therapy Devices,” (e) U.S. Provisional Application No. 62/865,468, filed Jun. 24, 2019, entitled “Transorbital NIR Light Therapy Devices,” (f) U.S. Provisional Application No. 62/871,889, filed Jul. 9, 2019, entitled “Transorbital NIR Light Therapy Devices,” (g) U.S. Provisional Application No. 62/892,513, filed on Aug. 27, 2019, entitled “Transorbital NIR Light Therapy Devices,” and (h) U.S. Provisional Application No. 62/902,182, filed Sep. 18, 2019, entitled “Transorbital NIR Light Therapy Devices,” the disclosures of each of which are incorporated herein, in their entireties, by reference.
This application is a continuation-in-part of U.S. patent application Ser. No. 16/419,369, filed May 22, 2019, entitled “Transorbital NIR Light Therapy Devices,” the disclosure of which is incorporated herein, in its entirety, by reference.
FIELD OF THE INVENTIONIllustrative embodiments generally relate to near infrared (NIR) light and, more particularly, illustrative embodiments relate to devices for treating the brain using NIR light.
BACKGROUND OF THE INVENTIONLight therapy consists of exposure to daylight or specific wavelengths of light using a lighting device, such as an LED. The light is administrated for a prescribed amount of time and at a particular dosage. For example, US Published Patent Application 2014-0358199 (Lim) discloses the intranasal delivery of the infrared light to the orbitofrontal cortex of the brain. The commercial embodiment of this application appears to be the Vielight 810® device. The Vielight 810® device comprises an infrared LED that is positioned into the nose and is powered by a battery pack.
Red/NIR light is significantly attenuated as it penetrates tissue. According to one Lim white paper, red/NIR light suffers a power loss of about 80% per mm penetration of tissue. (Lim, The Potential Of Intranasal Light Therapy For Brain Stimulation, Feb. 2, 2013, page 8). In another white paper, Lim reports that a) only 2.4% of infrared light penetrates 3 cm of dead tissue, and b) in live rats, only about 6% of photons with a wavelength of between 630 nm and 800 nm penetrate tissues up to 28 mm. (Lim, Inventor's Notes on Whole Brain Photobiomodulation with Vielight Neuro—a Transcranial-Intranasal Light Therapy Combination, January 2016, pages 8 and 16).
The recommended treatment time for the Vielight Intranasal device is 25 minutes. (Lim, Potential supra, abstract.)
U.S. Pat. No. 8,734,498 (Codman I) discloses a hand-held intranasal light device comprising an infrared LED powered by a battery contained within the handle of the device.
The literature reports several articles involving NIR irradiation of the forehead, with subsequent monitoring of cerebral blood flow via functional NIR spectroscopy. See, e.g., Kroczek, Addiction Biology, “Prefrontal functional connectivity measured with near-infrared spectroscopy during smoking cue exposure”, 2015. None of the FNIR articles reviewed report on neuronal activity in the OFC, thereby implying that NIR light did not reach the OFC from irradiation of the forehead. See. also, e.g., Leon-Carrion, “Functional Near-infrared Spectroscopy (fNIRS): Principles and Neuroscientific Applications” in Neuroimaging—Methods.
SUMMARY OF VARIOUS EMBODIMENTSIn accordance with one embodiment of the invention, a device for treating the brain includes a light source configured to emit near infrared light. The device also includes a collimator configured to receive the near infrared light emitted by the light emitter. The collimator is further configured to collimate the near infrared light. The device also includes an optic configured to focus collimated light. A reflector of the device is configured to change a direction of the collimated light. The reflector is at a distal end of the device, and the distal end is configured to fit between an upper portion of an eyelid of a patient and an orbital socket of the patient.
Among other things, the light source may be an LED or a laser. Some embodiments include a plurality of light sources. One or more of the light sources may emit near infrared light. Additionally, or alternatively, one or more of the light sources may emit red light. In some embodiments, the light source is configured to provide a dosage of light to the brain with an energy density of about around 1 J/cm{circumflex over ( )}2.
In various embodiments, the optic is a cylindrical lens. However, in some other embodiments, the optic may be a spherical lens. The collimator may be, for example, a parabolic mirror, an ellipsoidal mirror, a total internal reflection optic, a Fresnel lens, and/or a convex lens. The device may further include a housing having the light source, the collimator, and the optic therein. However, the reflector may be outside of the housing.
In accordance with another embodiment, a device for treating the brain includes a light emitter configured to emit near infrared light. The device also has a light guide. The light guide has a proximal end configured to receive the near infrared light from the light emitter. The light guide also has a distal end through which the near infrared light exits the light guide. The distal end is configured to fit between an upper portion of an eyelid of a patient and an orbital socket of the patient. The light guide also has a material configured to cause total internal reflection of the near infrared light between the proximal end and the distal end. The device includes a reflective portion configured to change a direction of the near infrared light that exits the light guide.
In some embodiments, the light guide may be a solid light guide. For example, the light guide may formed from acrylic. The material configured to cause total internal reflection may be a coating. The coating may be on the acrylic material. In some embodiments, the coating is aluminum. Furthermore, the reflector may be an exposed internal surface of the material configured to cause the total internal reflection.
The device may include a thermo electric cooler, and/or a heat sink coupled with the light source. Additionally, the device may include a housing having the light emitter and the light guide therein. The housing may have an open distal end through which the light guide passes.
In accordance with yet another embodiment, a method treats the brain by providing a device having a light emitter configured to emit near infrared light in a first direction. The method also provides a reflector configured to change the direction of the light from a first direction to a second direction. The method positions at least a portion of the device in an orbital cavity of the patient, such that the second direction is toward an orbitofrontal cortex of the brain of the patient.
The method may further emit a therapeutic dose of near infrared light from the light emitter. Additionally, the method may reflect the emitted near infrared light transorbitally towards the orbitofrontal cortex of the patient. Positioning the device may include placing the reflector at least about 15 mm into the orbital socket from a surface of a frontal bone of the patient.
In some embodiments, the device further includes a collimator. The method may include actuating the LED so that the NIR light exits the LED and is substantially collimated in the collimator. The device may further include an optic configured to focus the light towards the reflector.
Those skilled in the art should more fully appreciate advantages of various embodiments of the invention from the following “Description of Illustrative Embodiments,” discussed with reference to the drawings summarized immediately below.
In illustrative embodiments, a device treats the brain by transorbital delivery of near-infrared light (NIR light). Illustrative embodiments position a reflector in the periorbital space (e.g., the space between the eyelid and the orbital bone) and direct the NIR light towards the reflector. The reflector is configured to change a direction of the NIR light emitted by the light source. Thus, the light source emits NIR light in a first direction, towards the reflector, which redirects the light in a second direction towards the frontal cortex of the patient. The reflector advantageously allows the NIR light to be transmitted to the brain transorbitally, which generally is unable to fit a light source therein. Additionally, a collimator and/or focusing optic may be used to increase the amount of light that reaches the brain. Details of illustrative embodiments are discussed below.
Without wishing to be bound by any particular theory, the inventors believe that the NIR light treats the brain by stimulating transmembrane proteins in the mitochondria of brain cells, thereby improving the proteins catalytic activity and elevating ATP synthesis. Generally, to provide the desired clinical outcome, a minimum effective dosage of light reaches the brain. However, illustrative embodiments also account for a maximum permissible NIR light exposure limit that exists for patient safety.
While illustrative embodiments refer to NIR light, other spectrums of light may also be used to treat the brain. For example, short infrared light having a wavelength of between about 1.4 micrometers and about 3 micrometers, and/or red light having a wavelength of between about 625 nanometers and about 740 nanometers, may also be used to treat the brain. Thus, the discussion of the light source (also referred to as the light emitter) is not necessarily limited to NIR light. For example, in some embodiments the light emitter may emit infrared light and/or red light. Some embodiments may treat the brain using a plurality of light emitters each emitting NIR light, infrared light, and/or red light. Furthermore, while various embodiments may refer to the light source as an LED, it should be understood that the light source may additionally, or alternatively, be a laser.
In some embodiments, the light source delivers NIR light transcranially. However, the thickness and density of the patient's skull tends to attenuate the effective dosage of NIR light that reaches the brain. Accordingly, illustrative embodiments generally compensate for the attenuation by increasing the output intensity of the light source. The increased intensity may cause heat to build up at or around the eye, potentially causing patient discomfort and damaging tissue.
In some embodiments, the NIR light source 102 may be implanted in the brain (i.e., intracranial delivery). However, the invasive nature of the implanted light source 102 is not preferred from the patient's perspective. Additionally, the implanted light source 102 has a number of associated risks (e.g., infection, collateral damage from surgical procedure) and costs (e.g., anesthesia and/or medical professionals).
Some embodiments may provide intranasal transmission of NIR light. In some embodiments, the light source 102 may be inserted at a shallow depth in the nasal cavity. The bones and soft tissue between the nasal cavity and the brain result in large amounts of attenuation. Additionally, transnasal NIR light delivery may be unreliably attenuated by large increases in mucous (e.g., when the patient is sick) making precise delivery of effective light to the brain uncertain. Some embodiments insert the light source 102 deeper into the nasal cavity. However, depending on the insertion depth of the NIR light emitter 102 into the nasal cavity, the procedure may be too invasive for patient comfort. For example, mid-nose insertion depths may cause patient discomfort, require delivery by specialized operators, and are associated with risk of nose bleeds. F
Some other embodiments may stimulate the brain by positioning the light source 102 in the oral cavity. For example, the emitter may be positioned into the back of the patient's throat. NIR light delivery through the oral cavity provides access to certain parts of the brain (e.g., the brain stem), but similarly suffers from attenuation losses described previously when stimulating other parts of the brain (e.g., the orbito-frontal cortex).
The inventors discovered that NIR light can be efficiently and reliably transmitted to the frontal lobe of the brain (e.g., the orbito-frontal cortex) by transorbital transmission. Transorbital transmission provides a number of advantages, including non-invasive access to the frontal lobe of the brain, and/or reduced attenuation through the orbital bone relative to transcranial, transnasal, and/or oral methods. However, the periorbital space around the eye generally cannot safely fit a light source therein. Furthermore, an unshielded light source inserted in the periorbital space could potentially burn the tissue and/or the eye of the patient. Accordingly, illustrative embodiments use direct light from the light source towards a reflector position in the periorbital space, which in turn redirects the light towards the brain transorbitally.
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- a) a base 1 comprising a substantially concavo-convex distal end portion 3, wherein the substantially concavo-convex distal end portion comprises a metallic composition,
- b) a plurality of light emitters 102 attached to the convex side 7 of the substantially concavo-convex distal end portion, wherein the light emitter is oriented so that a majority of the light emitted by its LED faces away from the substantially concavo-convex distal end portion,
- c) a power source 9 in electrical connection with the plurality of light emitters.
Illustrative embodiments provide a number of advantages as discussed further below.
First, the metallic nature of the substantially concavo-convex distal end portion provides for heat dissipation, thereby drawing heat the powered light emitters and reducing the temperature at the eyelid.
Second, the light emitter is separated from the eyelid by a non-translucent concavo-convex distal end portion of the base. Thus, any light that is emitted by the light emitter towards the brain but then diffracted by tissue back towards the eye will be blocked by the metallic component. This provides a second measure of safety, thereby allowing for higher light fluxes to be used.
In some embodiments, and now referring to
Preferably the substantially concave distal end portion forms an arc of at least about 90 degrees, more preferably at least about 120 degrees, so that light emitter situated at the medial extreme can reach medial OFC structures like the gyrus rectus.
The inventors discovered that inserting a substantially concavo-convex element into the region between the eyelid and eye socket was fairly benign when the thickness of the element was about 1.5 mm, but became uncomfortable when the thickness of the element was about 6 mm. Thus, and now referring back to
Referring to
In some embodiments, the base can be a substantially tubular component adapted to fit between the eye and the eye socket. Typically, it has a diameter of between 25 and 35 mm. In other embodiments, the base is a portion of tube, typically extending in an arc of at least 90 degrees, preferably at least 120 degrees. Preferably it is made of a metallic material such as aluminum in order to effectively dissipate heat.
The power source 9 can be at least one or a plurality of batteries whose combined voltage output is adequate to drive the plurality of light emitters. The plurality of light emitters are put in electrical connection with the plurality of batteries. Typically, the power source 9 includes conventional electronics such as an on-off switch, a timer, and a constant-current element.
Now referring to
In some embodiments, the power source intermittent provides energy to the LEDs. In some embodiments, the power source comprises an alternating current (AC). In others, the power source comprises a direct current (DC) modified to resemble a square wave with a duty cycle between about 10% and 90%. Preferably the duty cycle is between 25% and 75%. In each of these cases, it is believed that the intermittent energy delivery gives the light emitter time to dissipate heat buildup, thereby lowering the maximum temperature at the light emitter. See Bozkurt, Biomedical Engineering Online, 2004, 3,9.
Now referring to
Now referring to
Thus, in some embodiments, and now referring to
In some embodiments, and now referring to
When the LED of the light emitter is situated proximate the eyelid, there is a concern with resistive heating from the p-n junction of the LED causing overheating of the eyelid skin. Thus, in some embodiments, the light emitter is moved proximally off the eyelid and a light pipe is interposed between the light emitter and the eyelid, wherein the light pipe carries light from the LED to the eyelid. Thus, any heating caused by the LED is carried out a safe distance away from the eyelid.
In some embodiments, and now referring to
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- a) a light guide, such as light pipe 71, comprising i) a substantially concavo-convex distal end portion 3 adapted to be positioned in a region between the eye and the eye socket, and ii) a proximal end portion 74 having at least one recess 75 adapted to receive at least one light emitter (preferably a plurality of light emitters); iii) an upper surface 77 and iv) a lower surface 79, wherein the concave portion thereof is displayed on the lower surface and the convex portion thereof is displayed on the upper surface;
- b) at least one light emitter 81 received in the proximal end portion of the light pipe, the light emitters oriented to shine in the distal (posterior) direction;
- c) a power source 9 (preferably at least one battery) electrically connected to the at least one light emitter;
- d) a metallic coating 84 covering the outer surface of the light pipe, and
- e) a light window 85 defined by an absence of metallic coating upon an upper surface of the a substantially concavo-convex distal end portion a substantially concavo-convex distal end portion.
Thus, preferably, the substantially concavo-convex distal end has a thickness of less than 5 mm, preferably less than 3 mm, more preferably less than 2 mm. These relatively thin sections allow for fairly comfortable distal (posterior) insertion of the element into the region between the eye and the eye socket to a distance of at least 10 mm, preferably at least 15 mm, more preferably at least 20 mm. Likewise, the substantially concavo-convex distal end section preferably has a thickness of less than 5 mm (preferably less than 3 mm) at a distance about 20 mm from the distal end, thereby keeping relatively thin the substantial majority of the light pipe that enters the eye socket.
Preferably, the light emitters are situated at least 30 mm, at least 50 mm or at least 70 mm away from the distal end of the light pipe. In this condition, any heat they generate will not affect the eyelid.
In some embodiments, the proximal end portion of the light pipe comprises recesses 75 adapted to receive light emitters. In some embodiments, the recesses are shaped as substantial cylinders in order to accommodate the conventional substantially cylindrical light emitter. In some embodiments, the recesses are shaped as substantial hemispheres in order to accommodate the conventional substantially hemispherical light emitter. In some embodiments, the light emitter recesses (and hence the light emitters themselves) are each defined by an axis that substantially intersects the distal wall of the substantially concavo-convex distal end portion, thereby pointing the light emitters substantially at the window. In some embodiments, the light emitter recesses are each defined by an axis A that substantially intersects the window, thereby pointing the light emitters directly at the window. In some embodiments, recesses that are on the upper surface are pointed at the lower surface at an angle that allows for the single reflection of light off the lower surface and into the window on the opposite upper surface. Likewise, in some embodiments comprising a linear array of light emitters spanning the medial-lateral aspect of the eye, the axes of the light emitter recesses (and hence the light emitters themselves) all substantially point directed forward so that there is a substantially equal distribution of light in the medial-lateral span.
Preferably the window 85 is situated at least 3 mm from the proximal end of the substantially concavo-convex distal end portion, thereby preventing a straight light path from the device to the eye. In some embodiments, the upper and lower surfaces of the light pipe are polished in order to better reflect incident light.
In some embodiments, the light emitters are selected to be the Vishay VSLY 5850 850 nm light emitter, which are advertised to have a very narrow emission beam (appearing to be around 10 degrees). This light saber nature of this light emitter allows targeting of the window and thus a large portion of the light emitted by these light emitters to travel directly to the window area without having been continually reflected off an upper or lower surface. Thus, in some embodiments, a majority of the light emitted by the light emitter is emitted in a 10 degree cone. In other embodiments, a majority of the light emitted by the light emitter is emitted in a 20 degree cone.
In other embodiments, the light emitters associated with the light pipe are 50 W or 10 W light emitters having an array of 850 nm LEDs, and are available, for example, from Hontiey at hontieychina.aliexpress.com
In some embodiments, the light pipe is made of a substantially unitary piece of substantially NIR-transparent plastic, such as an acrylic. Typically, the unitary piece is solid. In some embodiments, however, the light pipe can be hollow with reflective material on the inside surface thereof. In some of these embodiments, the light pipe can be a hollow unitary piece of metal, or a hollow unitary piece of one material (such as plastic) whose inner surface is coated by a reflective surface (such as a metallic coating).
In some embodiments, the distal wall of the light pipe is coated with a metallic material. When this feature is combined with a window that only starts 3-5 mm inward of the distal wall, there is a measure of safety in that light emanating from the window does not have a direct path to the eye, but rather takes a more circuitous route and thereby become subject to the severe attenuation afforded by transmission through tissue.
In other embodiments, the distal wall of the light pipe is uncoated and the window on the upper surface extends to the distal wall. In this condition, the light emanating from the light emitters is afforded an unobstructed path through the distal portion of the light pipe towards the orbitofrontal cortex.
In some embodiments, the light emitters and power source of the embodiment above (elements b and c) are provided in the form of a flashlight, and the light pipe can be considered as an adapter.
In some embodiments, heat pipes are used to transport heat away from the operating light emitters. Heat pipes are generally hollow tubes containing a fully enclosed evaporative fluid that evaporates near a heat source at a first end of the tube, is transported away from the heat source and rejects heat upon condensation at the opposite end of the tube. The cooled liquid is then transported back to the heat source end of the tube by wicking. Heat pipes are typically used in order to provide cooling to an environment.
In some embodiments, and now referring to
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- a) a base 1 comprising a substantially concavo-convex distal end portion 3,
- b) a light emitter 102 having a first light emitting face 107 and a second opposite face 109, and an NIR LED 200 on the first light emitting face,
- c) a heat pipe 132 having a first side 305 attached to the convex side 7 of the substantially concavo-convex distal end portion and a second side 303 attached to the second face of the light emitter,
- d) a power source 9 in electrical connection with the light emitter,
wherein the light emitter is located in the distalmost quarter 120 of the base.
In some embodiments, and now referring to
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- e) a base 121 comprising a substantially concavo-convex distal end portion 123,
- f) a plurality of light emitters 102, each light emitter having a first light emitting face 127 and a second opposite face 129,
- g) a plurality of heat pipes 132, each heat pipe having a first side 133 attached to the convex side 135 of the substantially concavo-convex distal end portion and a second opposite side 137 attached to the respective second faces of the plurality of light emitters,
- h) a power source 9 in electrical connection with the plurality of light emitters.
wherein the light emitters are located in the distalmost quarter 140 of the base.
In some embodiments, and now referring to
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- a) an NIR light emitter 102 having a lower side 200, an upper side 202, and an NIR LED 200 on the upper side, wherein NIR light is emitted only from the upper side,
- b) a substantially NIR-transparent insulator 203 (such as an optically transparent aerogel),
- c) a heat pipe 132 having a distal end portion 207 and a proximal end portion 209,
- d) a cooling element 213, and
- e) a power source 9,
wherein the distal end portion of the heat pipe is attached to the lower side of the NIR light emitter (preferably, by double sided, thermally conductive adhesive tape 211),
wherein the substantially transparent insulator is attached to the upper side of the NIR light emitter,
wherein the proximal end of the heat pipe is attached to the cooling element, and
wherein the light emitter is in electrical connection with the power source.
In some embodiments based upon
In some embodiments, and now referring to
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- a) an NIR light emitter 102 having a lower side 200 and an upper side 202, and an NIR LED 200 on its upper side,
- b) a thermal insulator 203 (such as a Styrofoam) having a central vertical through hole 206,
- c) a heat pipe 132 having a distal end portion 207 and a proximal end portion 209,
- d) a cooling element 213, and
- e) a power source 9,
wherein the distal end portion of the heat pipe and the lower side of the light emitter are attached (preferably, by double side thermally conductive adhesive tape 211),
wherein the thermal insulator is attached to the upper side of the NIR light emitter so that the through-hole is directly above the LED,
wherein the light emitter is in electrical connection with the power source.
In some embodiments based upon
Therefore, in some embodiments, schematically shown is an NIR light emitting device comprising:
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- a) an NIR light emitter having a base having a lower side and an upper side, and an NIR LED attached to the upper side of the base,
- b) a thermal insulator,
- c) a heat pipe having a distal end portion and a proximal end portion,
- d) a cooling element, and
- e) a power source,
wherein the distal end portion of the heat pipe is attached to the lower side of the base of the NIR light emitter,
wherein the thermal insulator is attached to the upper side of the base of the NIR light emitter,
wherein the proximal end of the heat pipe is attached to the cooling element,
wherein the NIR light emitter is in electrical connection with the power source.
In some embodiments, the cooling element comprises an ice pack or endothermic freeze pack. In other embodiments, as in
In some embodiments, the cooling element contacts the heat pipe in only the proximalmost third of the heat pipe. In some embodiments, the cooling element contacts the heat pipe in only the proximalmost half of the heat pipe. In some embodiments, the cooling element contacts the heat pipe in only the proximalmost two-thirds of the heat pipe. In some embodiments, the cooling element contacts the heat pipe upon substantially all but the distal most 20 mm of the heat pipe. In some embodiments, the cooling element contacts the heat pipe upon substantially all but the distal most one third of the heat pipe. In some embodiments, the cooling element contacts the heat pipe upon substantially all but the distal most one quarter of the heat pipe. In some embodiments, the cooling element contacts the heat pipe upon substantially all but the distal most one fifth of the heat pipe.
Preferably, the insulator that sits above the light emitter has a thermal conductivity of no more than 0.04 W/mK, more preferably no more than 0.03 W/mK, most preferably no more than 0.02 W/mK. In some embodiments, the insulator comprises an expanded polymer material, such as expanded polystyrene. In some embodiments, the insulator has a porosity of at least 95%, preferably at least 98%. In some embodiments, the insulator has a thickness of no more than 4 mm, preferably no more than 3 mm, more preferably no more than about 2 mm. In some embodiments, the length and width of the insulator is substantially the same as that of the light emitter it covers. In some embodiments, the insulator comprises an aerogel. In some aerogel embodiments, the base material is silica, while in others, it is a polymer. In some embodiments, the aerogel is substantially NIR transparent. In some embodiments thereof, one transparent aerogel is available from Aspen Aerogels, Inc. of Northboro, Mass., USA. In some embodiments, the transparent polymer aerogel is selected from embodiments of US 2019-0106543, the specification of which is incorporated by reference in its entirety.
In some heat pipe embodiments, the power source is a 9 Volt DC battery. In some embodiments, a lithium-based 9V battery provides a more stable, longer lasting power input. In other embodiments, the power source comprises alternating current, and in some embodiments thereof includes an AC/AC adaptor that preferably delivers energy in the form of 6V, 1 amp alternating current.
In some embodiments, electronics are included between the power source and light emitter to better manage the energy emitting by the battery or AC current. In some embodiments, the electronics includes a current driver that produces a constant non-degrading current from the DC battery. In some embodiments, the electronics includes current-limiting resistors configured to lower the current across the light emitter. In some embodiments, the electronics include a voltage splitter to lower the voltage across the light emitter while maintaining current. In some embodiments, an Arduino Uno timer is included as part of the electronics to initiate, time and end the light emitter irradiation. In some embodiments, a temperature sensor (Arduino Uno) monitors the temperature of the light emitter. In some embodiments, an optoisolator safeguards and protects the Arduino from possible power surges from the power source. In some embodiments, the optoisolator is connected to the current driver to keep the current stable and minimize temperature and current fluctuations. In some embodiments, the current driver is in series with a resistor and the light emitter in order to provide a desirable 500 mAmp, which was thought to be a desirable tradeoff amperage for producing light intensity while minimizing temperature increase. In some embodiments, a failsafe is coded into the Aruino to cut off power if the temperature of the light emitter reaches a certain maximum temperature.
In some embodiments, the electronics combined with the power source produces a voltage across the LED of about 3.2 volts and an amperage of about 0.45-0.5 amps.
The heat pipes of illustrative embodiments of the invention are typically hollow tubes with closed ends and a small amount of water under reduced pressure provided in the hollow bore. The inner surface of the heat pipe facing the bore possesses a wicking feature that can be grooved, mesh or sintered. In use, the water in the heat pipe is vaporized by heat flowing from the energized light emitter, where it travels to the cool end of the heat pipe as vapor. At the cool end, heat is rejected from the heat pipe, thereby resulting in condensation of the water vapor. The condensed liquid then travels back to the hot end of the heat pipe via the wicking structure, where the cycle is repeated. Preferably, the heat pipe has a length of between 100 mm and 250 mm; a width of between about 5 and 50 mm, and a height of between 1 mm and 5 mm. The 1 mm height heat pipe has the advantage that its profile can be easily fit into the space between the eyeball and eye socket, but has a disadvantage in that it produces a relatively low heat flux. In contrast, the 5 mm height heat pipe has the disadvantage that its profile does not easily fit into the space between the eyeball and eye socket, but has the advantage of producing a relatively high heat flux. In some embodiments, the heat pipe has a width to height ratio of at least 5:1. In some embodiments, the heat pipe has a width to height ratio of no more than 2:1. The very wide heat pipes have the advantage of carrying more than one light emitter, but they should be bent to accommodate the curvature of the eye socket in widths greater than about 10 mm. In some embodiments, the heat pipe is copper-based while in others, it is aluminum-based. In some embodiments, the heat pipe uses water as its heat flux fluid, while in other it uses acetone. As shorter heat pipes appear to transport more heat more quickly, in some embodiments, the length of the heat pipe is no more than 200 mm, preferably no more than 150 mm, more preferably no more than about 100 mm. In some embodiments, flat heat pipes from Wakefield-Vette of Pelham, N.H., USA are used.
In some embodiments, and now referring to
In use, illustrative embodiments of the device may be actuated to cause irradiation from the light emitter and the distal end of the device is pressed upon the eyelid into the space between the eyeball and the top of the eye socket. In some embodiments, the heat pipe is held at an angle to the ground with the condenser end up, to take advantage of the heated vapor's tendency to rise and the condensed liquid's tendency to fall. Therapy is preferably carried out for between about 15 and 30 minutes. US 2018-0193664 (Janssen) is incorporated by reference in its entirety.
In some embodiments, and now referring to
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- a) a light pipe 71 made of a substantially transparent material (such as acrylic) and comprising i) a substantially concavo-convex distal end portion 3 adapted to be positioned (e.g., inserted) in a region between the eye and the eye socket, and ii) a proximal end portion 74; iii) an upper surface 77; iv) a lower surface 79, wherein the concave portion thereof is displayed on the lower surface and the convex portion thereof is displayed on the upper surface; and v) a distal end face 80;
- b) at least one light emitter 102 positioned proximal of the proximal end portion of the light pipe, the light emitter having a NIR light emitting diode 82 oriented to shine in the distal (posterior) direction into the proximal end portion of the light pipe;
- c) a power source 9 (preferably at least one battery) electrically connected to the light emitter;
- d) a thermal insulator 51 (such as a cellulose sheet) covering at least the upper and lower surfaces of the light pipe;
- e) a metallic cladding layer 84 (such as a foil 183) covering the insulator, and
- f) a convex lens 72 positioned between the light emitter and the proximal end portion of the light pipe, the convexity of the convex lens facing distally to preferably focus light from the light emitter into the substantial center of the distal end face of the light pipe.
In some embodiments, the light emitter is a 50 W 850 nm NIR light emitter, available from Hontiey. See Hontiey Store at https://hontieychina.aliexpress.com/store/2188100. The purpose of the metal cladding layer is to protect the user from NIR light emanating through the sides of the light pipe. The purpose of the thermal insulator is to protect the user from the heat internally generated within the light pipe.
Now referring to
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- a) a heat pipe 132 having an upper surface 303, a lower surface 305, a proximal end portion 307 and a distal end portion 309;
- b) a Peltier thermoelectric element 311 having a lower surface 313 attached to the distal end portion of the heat pipe upon the upper surface of the heat pipe, and an upper surface 315;
- c) a light emitter 102 having an upper surface 319, a lower surface 321, and an NIR LED 200 attached to its upper surface, the lower surface of the light emitter attached to the upper surface of the thermoelectric element,
- d) an optional thermal insulator 325 (preferably an optically transparent insulator such as an aerogel) attached to the upper surface of the light emitter,
- e) at least one metallic heat sink 19 (preferably finned) attached to the proximal end portion of the heat pipe, and
- f) at least one power source 9 electrically connected to the thermoelectric element and the light emitter, wherein the power source powers the thermoelectric element to cool the upper surface of the thermoelectric element.
This embodiment is advantageous because it puts the cooling power of the Peltier chip very close to the active LED. In some embodiments of the
Referring now to
-
- a) a metal pipe 351 having a bore 354, an upper surface 352, a closed proximal end portion 353 and a closed distal end portion 355,
- b) a heat transfer fluid 356 (such as water) contained within the bore of the metal pipe,
- c) a light emitter 102 having an upper surface 359, a lower surface 361 and an NIR LED 200 attached to the upper surface 359,
- d) a thermal insulator 361 (preferably an optically transparent insulator such as a transparent aerogel) attached to the upper surface of the light emitter,
- e) a thermoelectric element 364 attached to the closed proximal end portion of the metal pipe,
- f) at least one power source 9 electrically connected to the thermoelectric unit and the light emitter, wherein the power source is adapted to power the thermoelectric unit to cool the metal pipe.
In some variants of
Referring now to
-
- a) a metal pipe 451 having a bore 454, an upper surface 452, an open proximal end portion 453 and a closed distal end portion 455,
- b) a light emitter 102 having an upper surface 459, a lower surface 460 and an NIR LED 463 attached to the upper surface 459,
- c) an optional thermal insulator 461 (preferably an optically transparent insulator such as a transparent aerogel) attached to the upper surface of the light emitter,
- d) a squeezable container 464 having a spout 471 fluidly attached to the open proximal end portion of the metal pipe,
- e) a burstable bag 481 located within the container,
- f) water 456 contained within the burstable bag 481,
- g) a plurality of endothermic beads 483 contained within the container,
- h) heat shrink tubing 468 surrounding the fluid attachment of the container and the metal pipe,
- i) insulation 466 surrounding the squeezable container;
- j) at least one power source 9 electrically connected to the light emitter.
In use, the squeezable container is squeezed, thereby rupturing the burstable bag containing the water and releasing the water. The water mixes with the endothermic beads, thereby solubilizing the beads, causing an endothermic reaction and lowering the temperature of the water. The chilled water travels to the closed distal end portion of the metal pipe, where it cools the active LED. Preferably, the diameter of the beads is greater than the diameter of the bore.
In some embodiments, the hollow light pipe 104 may be formed from metal and/or internally coated with NIR reflective metal. For example, the light pipe 104 may be a metal pipe, which advantageously dissipates heat into the surrounding air throughout its whole surface area. The NIR reflective surface is advantageous for internal reflectance and maximizing the irradiance output from the light pipe 104. Furthermore, some embodiments may not include the reflector 106.
-
- a) a light pipe (preferably hollow) having an upper surface, a lower surface, a proximal end portion and a distal end portion, wherein the lower and upper surfaces in the region of the distal end portion form a substantially concavo-convex shape,
- b) a convex lens having a convex distal surface and a proximal surface,
- c) a reflector having a proximal surface, a distal surface and a light reflective surface therebetween,
- d) a light emitter having a proximal end portion, a distal end portion having a distal end surface and a near infrared light emitting diode on the distal end surface,
- e) an optional heat sink (preferably a finned heat sink) having a proximal surface and a distal surface,
- f) an optional fan
wherein the proximal surface of the convex lens is attached to the distal surface of the reflector and oriented so that the convexity faces distally,
wherein the proximal end portion of the light pipe is attached to the distal surface of the reflector,
wherein the distal end portion of the light emitter is attached to the proximal surface of the reflector,
wherein the proximal end portion of the light emitter is attached to the distal surface of the heat sink, and
wherein the fan is attached to the proximal surface of the heat sink.
While
-
- a) an eyepiece
- b) a fiber optic cable having a proximal end portion and a distal end portion,
- c) a hollow housing having an upper surface, a lower surface, a proximal end portion and a distal endportion,
- d) a doublet lens having a distal surface and a proximal surface,
- e) a reflector having a proximal surface, a distal surface and a light reflective surface therebetween,
- f) a light emitter having a proximal end portion, a distal end portion having a distal end surface and a near infrared light emitting diode on the distal end surface,
- g) an optional heat sink (preferably a finned heat sink) having a proximal surface and a distal surface,
- h) an optional fan,
In the embodiment shown in
Although
Now referring to
-
- a) a light pipe (preferably hollow) having an upper surface, a lower surface, a proximal end portion and a distal endportion, wherein the lower and upper surfaces in the region of the distal end portion form a substantially concavo-convex shape,
- b) an optional convex lens having a convex distal surface and a proximal surface,
- c) a reflector having a proximal surface, a distal surface and a light reflective surface therebetween,
- d) a light emitter having a proximal end portion, a distal end portion having a distal end surface and a near infrared light emitting diode on the distal end surface,
- e) a phase change cooling element
wherein the proximal surface of the convex lens is attached to the distal surface of the reflector and oriented so that the convexity faces distally, wherein the proximal end portion of the light pipe is attached to the distal surface of the reflector, wherein the distal end portion of the light emitter is attached to the proximal surface of the reflector, and wherein the proximal end portion of the light emitter is attached to the distal surface of the cooling element.
Now referring to
-
- a) a light pipe (preferably hollow) having an upper surface, a lower surface, a proximal end portion and a distal end portion, wherein the lower and upper surfaces in the region of the distal end portion form a substantially concavo-convex shape,
- b) a convex lens having a convex distal surface and a proximal surface,
- c) a reflector having a proximal surface, a distal surface and a light reflective surface therebetween,
- d) a light emitter having a proximal end portion, a distal end portion having a distal end surface and a near infrared light emitting diode on the distal end surface,
- e) an optional first heat sink (preferably a finned heat sink) having a proximal surface and a distal surface,
- f) an optional first fan
- g) a heat pipe having a proximal end portion, and
- h) an optional second heat sink (preferably finned heat sink)
wherein the proximal surface of the convex lens is attached to the distal surface of the reflector and oriented so that the convexity faces distally, wherein the proximal end portion of the light pipe is attached to the distal surface of the reflector, wherein the distal end portion of the light emitter is attached to the proximal surface of the reflector, wherein the proximal end portion of the light emitter is attached to the distal surface of the heat sink, wherein the fan is attached to the proximal surface of the heat sink, wherein the heat pipe is attached lengthwise to the light pipe, and wherein the second heat sink is attached to the proximal end portion of the heat pipe.
Whereas
Also, in some embodiments, the reflector is eliminated.
In some embodiments, the light delivery device includes:
-
- a) a light pipe (e.g., solid) having an upper surface, a lower surface, a proximal end portion and a distal end portion, wherein the lower and upper surfaces in the region of the distal end portion form a substantially concavo-convex shape,
- b) a metallic coating on the upper and lower surfaces of the light pipe,
- c) a light emitter having a proximal end portion, a distal end portion having a distal end surface and a near infrared light emitting diode on the distal end surface,
- d) an optional heat sink (preferably a finned heat sink) having a proximal surface and a distal surface, and
- e) an optional fan
The distal end portion of the light emitter may be attached to the proximal end portion of the light pipe. The proximal end portion of the light emitter may be attached to the distal surface of the heat sink. The fan may be attached to the proximal surface of the heat sink.
Now referring to
-
- a) a light pipe (preferably hollow) having an upper surface, a lower surface, a proximal end portion and a distal endportion, wherein the lower and upper surfaces in the region of the distal end portion form a substantially concavo-convex shape,
- b) a convex lens having a convex distal surface and a proximal surface,
- c) a reflector having a proximal surface, a distal surface and a light reflective surface therebetween,
- d) a light emitter having a proximal end portion, a distal end portion having a distal end surface and a near infrared light emitting diode on the distal end surface,
- e) an optional heat sink (preferably a finned heat sink) having a proximal surface and a distal surface,
- f) an optional fan
- g) an optional insulation layer having an inner and outer surface, and
- h) an optional metal foil
- i) an optional porous plastic layer (such as Styrofoam 182)
wherein the proximal surface of the convex lens is attached to the distal surface of the reflector and oriented so that the convexity faces distally, wherein the proximal end portion of the light pipe is attached to the distal surface of the reflector, wherein the distal end portion of the light emitter is attached to the proximal surface of the reflector, wherein the proximal end portion of the light emitter is attached to the distal surface of the heat sink, and wherein the fan is attached to the proximal surface of the heat sink, wherein the inner surface of the insulating layer is attached to the upper and lower surfaces of the light pipe, wherein the metal foil is attached to the outer layer of the insulating layer.
wherein the porous plastic layer is attached to the distal end portion of the light pipe on the upper and lower surfaces thereof.
Whereas
Now referring to
-
- a) a hollow light pipe having an upper surface, a lower surface, a proximal end portion and a distal endportion, wherein the lower and upper surfaces in the region of the distal end portion form a substantially concavo-convex shape, wherein at least one of the upper and lower surfaces has a port
- b) a convex lens having a convex distal surface and a proximal surface,
- c) a reflector having a proximal surface, a distal surface and a light reflective surface therebetween,
- d) a light emitter having a proximal end portion, a distal end portion having a distal end surface and a near infrared light emitting diode on the distal end surface,
- e) an optional heat sink (preferably a finned heat sink) having a proximal surface and a distal surface,
- f) an optional first fan
- g) tubing having a first and second end,
- h) a second fan
wherein the proximal surface of the convex lens is attached to the distal surface of the reflector and oriented so that the convexity faces distally,
wherein the proximal end portion of the light pipe is attached to the distal surface of the reflector,
wherein the distal end portion of the light emitter is attached to the proximal surface of the reflector,
wherein the proximal end portion of the light emitter is attached to the distal surface of the heat sink, and
wherein the first fan is attached to the proximal surface of the heat sink,
wherein the first end of the tubing is connected to the port, and
wherein the second end of the tubing is connected to the second fan.
Also, in some embodiments, the reflector is eliminated.
In the
Now referring to
-
- a) a light pipe (preferably hollow) having an upper surface, a lower surface, a proximal end portion and a distal endportion, wherein the lower and upper surfaces in the region of the distal end portion form a substantially concavo-convex shape,
- b) a convex lens having a convex distal surface and a proximal surface,
- c) a reflector having a proximal surface, a distal surface and a light reflective surface therebetween,
- d) a light emitter having a proximal end portion, a distal end portion having a distal end surface and a near infrared light emitting diode on the distal end surface,
- e) an optional heat sink (preferably a finned heat sink) having a proximal surface and a distal surface,
- f) an optional fan
- g) a peltier thermoelectric element having a proximal surface and a distal surface,
wherein the proximal surface of the convex lens is attached to the distal surface of the reflector and oriented so that the convexity faces distally,
wherein the proximal end portion of the light pipe is attached to the distal surface of the reflector,
wherein the distal end portion of the light emitter is attached to the proximal surface of the reflector,
wherein the proximal end portion of the light emitter is attached to the distal end surface of the peltier thermoelectric element,
wherein the proximal end surface of the peltier thermoelectric element is attached to the distal surface of the heat sink, and
wherein the fan is attached to the proximal surface of the heat sink.
Whereas
Also, in some embodiments, the reflector is eliminated.
Now referring to
-
- a) a hollow light pipe having an upper surface, a lower surface, a proximal end portion and a distal endportion, wherein the lower and upper surfaces in the region of the distal end portion form a substantially concavo-convex shape, wherein at least one of the upper and lower surfaces has a port 187 connecting an inside of the light pipe to an outside of the light pipe,
- b) a convex lens having a convex distal surface and a proximal surface,
- c) a reflector having a proximal surface, a distal surface and a light reflective surface therebetween,
- d) a light emitter having a proximal end portion, a distal end portion having a distal end surface and a near infrared light emitting diode on the distal end surface,
- e) an optional heat sink (preferably a finned heat sink) having a proximal surface and a distal surface,
- f) an optional first fan
wherein the proximal surface of the convex lens is attached to the distal surface of the reflector and oriented so that the convexity faces distally,
wherein the proximal end portion of the light pipe is attached to the distal surface of the reflector,
wherein the distal end portion of the light emitter is attached to the proximal surface of the reflector,
wherein the proximal end portion of the light emitter is attached to the distal surface of the heat sink, and
wherein the first fan is attached to the proximal surface of the heat sink.
Also, in some embodiments, the reflector is eliminated.
To deliver NIR light transorbitally, illustrative embodiments position the device 100, or a portion thereof, in the orbital socket of the patient, such that the NIR light is emitted towards the frontal lobe of the brain. The emitter 102 has a light emitting surface that emits the NIR light towards a light guide 104. The light guide 104 guides the light towards a first direction. In some embodiments, the first direction is generally towards a distal end 130 of the housing 118 of the device 100. Additionally, or alternatively, the first direction may be towards a reflector 106 that is configured to reflect the light towards a second direction (discussed further below).
The light guide 104 may be formed from a solid material, such as a transparent acrylic material. While the light guide 104 can take alternate forms (e.g., hollow), in this embodiment the light guide may be formed from a solid material. In some embodiments, the light guide 104 has a proximal end 112 configured to receive the emitted NIR light from the emitter 102, and a distal end 114 through which the light exits the guide 104. In some embodiments, the light may enter and exit the guide 104 near the proximal end 112 and the distal end 114, respectively. Accordingly, illustrative embodiments should not be considered as being limited to receiving and/or transmitting light from end surfaces of the guide 104. Indeed, in some embodiments, the upper distal surface of the light guide 104 has an opening and/or a window through which the NIR light escapes.
During transorbital NIR light delivery, a tip 134 of the light guide 104 is positioned between the patient's eyelid and eye socket (i.e., in the periorbital space around the patient's eye). Accordingly, as discussed further below with reference to
In some embodiments, the reflector 106 may be formed by an exposed portion of reflective material 116 on the light guide 104. The reflective material 116 is configured to transmit all or substantially all of the received light from the proximal end 112 to the distal end 114 of the light guide 104. To that end, the material 116 may be configured to cause total internal reflection of the NIR light between the proximal end 112 and the distal end 114 of the light guide 104. The material 116 may be formed of a metal, such as aluminum. In some embodiments, the metallic material 116 may form a coating around the solid light guide 104. Thus, the NIR light may reflect off the inner surface of the reflective material 116 as it travels through the light guide 104 towards the reflector 106.
In some embodiments, the reflective material 116 may be coated on all of the surfaces of the device 100 except for the light guide-emitter interface and an opening 152 or a NIR light transparent window on the distal tip 134 (e.g., the dorsal face of the tip 134). A portion of the reflective material 116 is configured to reflect light towards the periorbital space through the opening 152 and/or window, and thus, acts as the reflector 106.
Because the reflective material 116 may absorb some of the light as it travels along the guide 104, illustrative embodiments may use a higher intensity light emitter 102 (also referred to as a light source 102) than may otherwise be required to deliver the effective dosage if none of the light was absorbed. For example, the light source 102 may be, for example, a Hontiey or Chanzon 10 W 850 nm LED. However, some other embodiments may include a 50 W 850 nm Hontiey or Chanzon LED.
During operation the light source 102 may produce heat that undesirably impacts patient comfort (e.g., burning the skin). The device 100 may include one or more thermal management systems to help manage excess heat. For example, illustrative embodiments may include a heat sink 19 coupled with the non-light emitting surface of the light source 102. The heat sink 19 may have fins to enhance heat transfer. Alternatively, or additionally, a heat pipe may be coupled with the light emitter 102. Some embodiments may include a fan 219 configured to convectively cool the heat sink 19 and/or the heat pipe. The fan 219 may be mounted to the housing 118 via a fan mount 128. The housing 118 may also include air vents 126 to assist with air circulation and cooling. Other thermal management systems that may be used with illustrative embodiments are described, for example, with reference to
In some embodiments, the device 100 has the reflector 106 (e.g., the portion of the material 116 that reflects light towards the brain) at or near the distal end 130. The reflector 106 is configured to change a direction of the NIR light towards the frontal lobe of the patient. For example, the reflector 106 may redirect the light towards the orbito-frontal cortex and/or away from the back of the patient's eye. To that end, the light guide 104 may have an opening and/or a NIR light transparent window through which the NIR light exits the light guide 104. In some embodiments, the reflector 106 may be a mirror (e.g., coupled to the light guide 104 or another portion of the device 100). Alternatively, the reflector 106 may be an exposed inner surface of the material 116. For example, the reflector 106 may be an inner surface of the aluminum coating. In various embodiments, the reflector 106 has a reflectance of at least 80% for NIR light and/or red light. Furthermore, in some embodiments, the reflector 106 may have a reflectance of at least 90%, at least 93%, at least 95%, or at least 99%, for NIR light and/or red light.
As shown in
The reflector 106 can be formed from a portion of NIR reflective metal, and/or NIR reflective coated metal or plastic. In some embodiments, the reflector 106 is positioned in a straight extruded tip. This provides the advantage of minimizing internal reflectance at the light guide-air interface.
The device 100 has a hollow light guide 104 with the reflector 106 configured to redirect light emitted by the light source 102 (e.g., an LED array). As discussed further below, illustrative embodiments additionally contain optics that provide a number of advantages, including increasing the net effective dosage of NIR light that reaches the brain. Illustrative embodiments increase the net effective NIR light that reaches the brain while remaining within maximum permissible exposure limits. To that end, the device 100 may include a collimator 146 and an optic 148 configured to focus the NIR light to increase the effective amount of light that reaches the brain without surpassing the permissible exposure limit.
The collimator 146 is configured to receive and collimate the NIR light emitted by the light emitter 102. Typically, when the light is emitted by the source 102, it spreads into a wide cone. By positioning the collimator 146 distal to the light emitting surface, the collimator 146 collects the light beams and collimates them after they are emitted. In various embodiments the collimator 146 may be, for example, a parabolic mirror, an ellipsoidal mirror, a Fresnel lens, and/or a convex lens. Preferably, the collimator 146 is configured to cause total internal reflection.
To further enhance the amount of NIR light that reaches the brain, illustrative embodiments may include a focusing optic 148, such as a cylindrical lens, configured to focus the NIR light. In some embodiments, the optic 148 may be positioned distal to the collimator 146 (e.g., with or without an air gap between the collimator 146 and the optic 148). Accordingly, the optic 148 may focus collimated light. However, in some other embodiments, the device 100 may include the optic 148 without the collimator 146, or vice-versa. Thus, in some embodiments, the optic 148 may focus uncollimated light.
In illustrative embodiments, the focusing optic 148 focuses the light in the first direction 109 towards the reflector 106. Thus, a complete light guide 104 may not be necessary (e.g., because the light is not diffusively spreading). Accordingly, illustrative embodiments may merely include the tip 134 of the light guide 104. The focusing optic 148 may focus the NIR light towards the reflector 106. Indeed, some embodiments may include no light guide 104 at all, and instead may merely have the reflector 106 (e.g., coupled with the housing 118 via a mechanical support).
The light is shown as traveling the first direction 109A and 109B. When the focused light contacts the reflector 106, the light is reflected towards the second direction 111A and 111B, respectively. The light exits the light guide 104 through the opening 152. During use, the tip 134 is positioned in the periorbital space, and the opening 152 faces up towards the patient's brain. Accordingly, illustrative embodiments are configured such that the focused beam is redirected by the reflector 106 to transmit light transorbitally towards the patient's brain. As an additional advantage, the tip 134 may shield the eye from light exposure (e.g., backscatter).
In some embodiments, the hollow light guide 104 is formed of metal and may have a polished inner face 155 that acts as the reflector 106. The light travels in the second direction 111 towards the patient's brain through the opening 152 in the light guide 104. Instead of the opening 152, some embodiments may include an NIR transparent window. In some embodiments, the hollow light guide 104 may be purely structural, merely supporting the reflector 106 at its tip 134. In some embodiments, custom focusing optics 148 may be used to produce an output light spot shape that matches the geometry of the reflector 106, as discussed with reference to
In illustrative embodiments, the reflector 106 is angled relative to a longitudinal axis of the hollow light pipe 104. In some embodiments, the reflector 106 is angled such that the light exits the window and/or opening 152 at an angle substantially perpendicular to the longitudinal axis of the light pipe.
The tip 134 of the hollow light pipe 104 may be formed from a light reflective material. The tip 134 has an upper wall, a lower wall, and opposing side walls connecting the upper and lower walls. Preferably, the lower and upper walls of a distal end of the tip 134 form a substantially concavo-convex shape, wherein the upper wall has the opening 152
There is, however, an operational risk associated with using a convergent light source. If the device 100 is held at such a length outside of the intended operating parameters, such that the focal point is on or close to the skin 158 surface, the high power density can damage the skin 158. The penetration depth of light in tissue is inversely related to beam divergence and directly related to power density. In the case of the three focal length conditions, the penetration depth may increase as the focal length of the optics becomes greater than the distance to the reflector 106. The desirability of each embodiment lends to the depth and desired irradiance of the target neural tissue, as well as operational safety.
While the embodiments shown in
Focusing optics 148 can be leveraged to control the output of the light source 102 to the desired uniformity, spot shape, and size. Optics 148 can also improve power efficiency by controlling the path of divergent light from a light source 102. To collimate the divergent beam of the light source 102, a Total Internal Reflection (TIR) collimator 146 is placed at the interface of the light source 102. In the instances where a round spot is desired, the spherical lens optic 148 shown in
The process 400 begins at step 420, which positions the device 100 in the peri-orbital space of the patient. Specifically, the tip 134 at the distal end 130 of the housing 118 is positioned between the eye lid and orbital bone. To that end, the tip 134 preferably has a substantially concavo-convex shape to better fit within the concavo-convex cavity between the eye and the orbital bone and to improve compliance and optical interface. Additionally, the tip 134 is thin to assist with better positioning within the small periorbital space. Accordingly, the tip 134 may have a thickness of less than 5 mm, less than 3 mm, or less than 2 mm. These relatively thin sections allow for fairly comfortable distal (posterior) insertion of the tip 134 into the region between the eye and the eye socket to a distance of at least 8 mm, at least 10 mm, or at least 15 mm. Additionally, or alternatively, some embodiments may position the tip 134 into the orbital socket at most about 25 mm, or at most about 20 mm. In some embodiments, the substantially concavo-convex tip 134 preferably has a thickness of less than 5 mm at an insertion depth of about 20 mm from the distal end 130, thereby keeping the substantial majority of the light pipe 104 that enters the eye socket relatively thin. In some embodiments, a flange on the hollow light guide 104 connects to the housing 118 at 15 mm from the distal point of the tip 134, limiting insertion depth into the orbit. In some embodiments, this distance is in the range of 5 mm to 20 mm.
When the tip 134 is positioned in the periorbital space, an NIR light transparent window and/or an opening 152 is preferably facing upward towards the brain, such that any light that escapes the light guide 104 is directed towards the brain. To that end, the tip 134 has a reflector 106 configured to change the direction of light pulsed by the light source 102 from the first direction 109 to the second direction 111.
In some embodiments, light thermalization at the skin 158 may limit the amount of light that can be pulsed towards the brain is the biggest barrier in the development of this device. In addition to the various thermal management systems described through the application, another attempt to mitigate the thermalization may include applying a cooling gel at the eyelid in contact with the distal tip 134 of the device 100. For example, menthol or lidocaine rub may be utilized to lower the temperature at the eyelid, and/or to provide a cooling sensation to the eyelid and give a tactile stimulus to the patient.
The process 400 then proceeds to step 422, which pulses light from the light source 102. As described previously, the light source 102 is configured to pulse NIR light to treat the brain. Some embodiments may have a plurality of light sources 102 (e.g., as shown in
Because the light source 102 tends to run hot after use, the device 100 includes a thermal management system, such as a heat sink 19 and/or fan 219 attached to the back face of the LED to maintain the emitter 102 temperature at the recommended, safe operating point. This ensures quality and consistency of light throughout the treatment, as well as prevents the LED from operational damage. Air vents 126 are built into the housing 118 adjacent to the intake face of the fan 219 and the sides of the heat sink 19 for thermal exhaust. Lastly, a cable harness 162 on the posterior face of the housing 118 leads to a power controller input. The controller enables pulse width modulation input to the light source.
The process 400 then proceeds to step 424, which collimates the light emitted by the light source 102. To that end, the collimator 146 is positioned distally of the light source 102, such that it receives all or substantially all of the emitted light, and collimates it. In illustrative embodiments, the collimator 146 assists with increasing the energy density of the emitted light that ultimately reaches the brain. The collimator may be, for example, a TIR optic.
The process 400 then proceeds to step 426, which focuses the collimated light by passing it through the focusing optic 148. The focusing optic 148 may be, for example, a spherical lens used to focus the beam. Additionally, or alternatively, the focusing optic 148 may be a cylindrical lens, or a custom shaped lens. Furthermore, some embodiments may use a plurality of lenses in series to produce a custom output spot 156 shape (as shown in
Focusing the light results in a focal point for the light. In some embodiments, the device 100 is configured such that the focusing optic 148 has a focal point at the distal tip 134 of the light guide 104. For example, the tip 134 may include a hollow metal portion whose inner face is polished to work as a reflector 106 that changes the light path direction. In some other embodiments, however, the focal point may be proximal to, or distal to, the reflector.
The process 400 then proceeds to step 428, which reflects the light towards the brain. To that end, the tip 134 and/or the light guide 134 has a reflector 106 configured to change a direction of the light from the first direction 106 towards the reflector 106 to the second direction 111 towards the brain. In some embodiments, the first direction 109 may be the direction that light is emitted from the source 102. In some other embodiments, the first direction 109 may be the direction that the light comes from prior to reaching the reflector. In some embodiments, the first direction 109 may be the direction of light collimated by the collimator 146 and/or focused 148 by the focusing lens 148. The reflector 106 may be, for example, a mirror, a polished metal surface of the tip 134, and/or the internal surface of an NIR light reflective coating on the solid light guide 104 (e.g., inner surface of material 116 in
The process 400 then asks, at step 430, whether more light is needed for the treatment. If more light is needed, then the process returns to step 422, where light is pulsed again. Illustrative embodiments dose between 0.1-1.0 J/cm2 across different regions of the orbitofrontal cortex. In some embodiments, the process 400 is repeated until 0.1-10 J/cm2 of light reaches the brain. In some embodiments, the process is repeated at intervals, to allow the device 100 to cool off, and to prevent or reduce the risk that maximum permissible exposure limits are reached for the skin 158 receiving the light. The maximum permissible exposure limit for 850 nm light is approximately 400 mW/cm2 at the skin 158. In some embodiments, a therapeutic dose of emitted light is about 400 mW/cm2, so as to maximize the light reaching the brain without overcoming the maximum permissible exposure limit. In some embodiments, the light may be dosed every 48 hours. In some embodiments, the process may be repeated for three consecutive days, at hours 0, 24, and 48.
If no more light is needed for treatment, then the device 100 is removed from the periorbital space and the process comes to an end. Although step 432 is shown as coming after step 430, it should be understood that in some protocols having an extended wait between dosing (e.g., every 5 minutes or more) the device 100 may be removed from the periorbital space, and simply repositioned at the time of the subsequent dose.
Illustrative embodiments use the temperature drop of the disposable tank 168 and its contents to cool the non-light emitting surface of the LED light source 102. The tank 168 may be fitted with two brackets: a thermal insulator like rubber to reduce heat exchange on the side opposite of the LED, and a metal, thermally conductive bracket 170 attached to the non-light emitting surface of the LED 200. In some embodiments, the thermally insulating bracket 172 encompasses the majority of the exposed surface area of the tank 168. Heat exchange occurs between the LED light source 102 and the LPG tank 168 through the metal bracket 170.
Compressed air escaping the tank 168 can be leveraged to cool other aspects of the device 100. As more gas is released, the gas cools relative to room temperature when the heat transferred to the tank 168 by the LED is less than that consumed by the phase change in the tank 168. In some embodiments, the cold gas may be used to cool the skin-device interface.
The LED is mounted on a thermally conductive heat pipe configured to wick heat from the hotter evaporative side to the cooler condensing side. Some embodiments could also be used with a typical thermally conductive material like copper. On the cooler side is mounted a Thermoelectric cooling (Peltier) chip. This acts to keep the cool side of the heat pipe cool at all times. The hot side of the TEC is then mounted on a heat sink and fan in order to dissipate heat quickly and efficiently.
Illustrative embodiments may include a second reflective surface may be added distally of the collimator in order to guide collimated light away from the eyeball and towards the orbitofrontal cortex.
-
- a) a first heat pipe having a proximal end portion, a distal end portion, and an upper surface,
- b) a light emitter comprising a lower surface, an upper surface, and an NIR LED on the upper surface,
- c) a peltier thermoelectric element having a cold surface and a hot surface,
- d) a second heat pipe having a proximal end portion and a distal end portion, and
- e) a cooling element (such as a phase change cooling device)
wherein the lower surface of the light emitter is attached to the upper surface of the distal end portion of the first heat pipe, wherein the cold surface of the peltier thermoelectric element is attached to the proximal end portion of the first heat pipe, wherein the hot surface of the peltier thermoelectric element is attached to the distal end portion of the second heat pipe, wherein the cooling element is attached to the proximal end portion of the second heat pipe.
Therefore, there is provided, as in
While illustrative embodiments refer to the optic as focusing collimated light, it should be understood that some embodiments do not have a collimator. Accordingly, the above discussion referring to focusing collimated light also applies to light that is not collimated.
A person of skill in the art understands that illustrative embodiments provide a number of advantages. For example, advantages include that a reflector positioned in the periorbital cavity is used to enable pulsing of light transorbitally. Otherwise, it is difficult to deliver light transorbitally. Illustrative embodiments also provide a light guide, collimator, and/or focusing optic to assist with delivering all, or substantially all, of the light to the reflector. Furthermore, illustrative embodiments optimize the amount of light delivered to the brain while minimizing the exposure of tissue (e.g., skin) to high amounts of light and remaining within the maximum permissible exposure limit.
Disclosed embodiments, or portions thereof, may be combined in ways not listed above and/or not explicitly claimed. In addition, embodiments disclosed herein may be suitably practiced, absent any element that is not specifically disclosed herein. Accordingly, the invention should not be viewed as being limited to the disclosed embodiments. Additionally, although some components and/or features of the device 100 may be described as optional, illustrative embodiments should not be interpreted as requiring components and/or features that have not explicitly been described as optional.
The embodiments of the invention described above are intended to be merely exemplary; numerous variations and modifications will be apparent to those skilled in the art. Such variations and modifications are intended to be within the scope as defined by any of the appended claims.
Claims
1. A device for treating the brain, the device comprising:
- a light source configured to emit near infrared light;
- a collimator configured to receive the near infrared light emitted by the light emitter, the collimator further configured to collimate the near infrared light;
- an optic configured to focus collimated light; and
- a reflector configured to change a direction of the collimated light, the reflector being at a distal end of the device, the distal end being configured to fit between an upper portion of an eyelid of a patient and an orbital socket of the patient.
2. The device as defined by claim 1, wherein the light source is an LED or a laser.
3. The device as defined by claim 1, further comprising a plurality of light sources.
4. The device as defined by claim 1, wherein the optic is a cylindrical lens.
5. The device as defined by claim 1, wherein the collimator is a parabolic mirror, an ellipsoidal mirror, a total internal reflection optic, a Fresnel lens, and/or a convex lens.
6. The device as defined by claim 1, further comprising a housing having therein the light source, the collimator, and the optic, wherein the reflector is outside of the housing.
7. The device as defined by claim 1, wherein the light source is configured to provide a dosage of light to the brain with an energy density of about around 1 J/cm{circumflex over ( )}2.
8. A device for treating the brain, the device comprising:
- a light emitter configured to emit near infrared light;
- a light guide having: a proximal end configured to receive the near infrared light from the light emitter, a distal end through which the near infrared light exits the light guide, the distal end configured to fit between an upper portion of an eyelid of a patient and an orbital socket of the patient, and a material configured to cause total internal reflection of the near infrared light between the proximal end and the distal end; and
- a reflective portion configured to change a direction of the near infrared light that exits the light guide.
9. The device as defined by claim 8, wherein the light guide is a light pipe formed of a solid material.
10. The device as defined by claim 9, wherein the solid material includes acrylic.
11. The device as defined by claim 8, wherein the material configured to cause total internal reflection is a coating.
12. The device as defined by claim 11, wherein the coating is aluminum.
13. The device as defined by claim 8, further comprising a thermo electric cooler, and/or a heat sink coupled with the light source.
14. The device as defined by claim 8, further comprising a housing having the light emitter and the light guide therein, the housing having an open distal end through which the light guide passes.
15. The device as defined by claim 8, wherein the reflector is an exposed internal surface of the material configured to cause the total internal reflection.
16. A method for treating the brain, the method comprising:
- providing a device having: a light emitter configured to emit near infrared light in a first direction, and a reflector configured to change the direction of the light from a first direction to a second direction;
- positioning at least a portion of the device in an orbital cavity of the patient, such that the second direction is toward an orbitofrontal cortex of the brain of the patient.
17. The method as defined by claim 16, further comprising:
- emitting a therapeutic dose of near infrared light from the light emitter;
- reflecting the emitted near infrared light transorbitally towards the orbitofrontal cortex of the patient.
18. The method as defined by claim 16, wherein the device further comprises a collimator, the method further actuating the LED so that the NIR light exits the LED and is substantially collimated in the collimator.
19. The method as defined by claim 16, wherein the device further comprises an optic configured to focus the light towards the reflector.
20. The method as defined by claim 16, wherein the positioning includes placing the reflector about 10 mm into the orbital socket from a surface of a frontal bone of the patient.
Type: Application
Filed: Dec 10, 2020
Publication Date: Apr 1, 2021
Inventors: Griffin Cummings (Brighton, MA), Thomas M. DiMauro (Southboro, MA), Alexander Samaha (Newton, MA), Alexandru Paunescu (Clinton, NJ), Mark T. Hall (Bridgewater, MA)
Application Number: 17/117,678