Controlling illumination and brain temperature in optogenetic activation

Abstract

A device (22) implanted in an organ, the device includes: (a) an energy consuming device (ECD) (44) configured to receive electrical power and to apply energy to the organ, and (b) a resonance circuit (21), which is configured to (i) receive a magnetic field (MF), and (ii) convert the MF to the electrical power, a resonance frequency (25) of the resonance circuit (21) depending on a temperature of the organ, and in response to a change in the temperature of the organ, the resonance circuit (21) is configured to change an intensity of the electrical power supplied to the ECD (44).

Description

[0001] CONTROLLING ILLUMINATION AND BRAIN TEMPERATURE IN QPTQGENETIC ACTIVATION

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Patent Application 63 / 507,997, filed June 14, 2023, whose disclosure is incorporated herein by reference.

[0004] FIELD OF THE INVENTION

[0005] The present invention relates generally to optogenetic -based medical devices, and particularly to methods and systems for optogenetic illumination with thermal protection and closed loop control.

[0006] BACKGROUND OF THE INVENTION

[0007] Some neurological diseases, such as but not limited to Parkinson’s disease, Epilepsy, Neuropathic pain, and other types of neurological diseases and / or disorders, may be treated using several techniques.

[0008] For example, U.S. Patent Application Publication 2005 / 0143330 to Mandel et al., describes a method for treating Parkinson’s disease in patients exhibiting increasing resistance to the administration of L-dopa due to loss of aromatic L-amino acid decarboxylase activity in striatal neurons comprises transfection of the caudate and / or putamen regions with a viral vector encoding AADC. The vector preferably has a promoter system provided for the expression of the AADC nucleic acid, and is injected at a slow rate, at a level designed to restore AADC activity to tissues undergoing progressive loss of that activity. The AADC renewed activity permits conversion of L-dopa, in the brain, to dopamine.

[0009] There are implanted devices, such as deep brain stimulator (DBS), and responsive neurostimulator (RNS) that are applying electrical stimulation to the brain for treating several types of neurological diseases and / or disorders that are not controlled by medication.

[0010] U.S. Patent 11,779,658 to Schorge et al., describes expression vectors comprising engineered genes. The invention provides expression vectors, nucleic acids, vector particles and methods of treatment involving these vector particles, comprising an engineered KCNA1 gene encoding an edited Kvl.l potassium channel, as well as methods of confirming the presence of engineered KCNA1 mRNA in a cell. The features of the engineered KCNA1 gene combine to advantageously enhance the translation and activity of the Kvl.l protein and improve detection of KCNA1 gene expression in a cell and can be used for example in the treatment of epilepsy and similar neurological disorders. Optogenetic activations may be used in treating various types of neurological diseases (e.g., Parkinson’s disease) by illuminating the respective areas in the tissue in question (e.g., human brain), as described in more detail below. U.S. Patent 11,180,537 to Mohanty et al., describes optogenetic modulation by multi-characteristic opsins for vision restoration and other applications.

[0011] Brain catheterization techniques have evolved for treating acute neurological diseases and preventing events, such as strokes, aneurysms, and stenosis. Stents that are designated for brain vasculature are required to be designed with sufficiently small size (and tight control of other attributes) compared to stents targeted to be used in other procedures performed in the general vascular system of a human. Such requirements and techniques are described, for example, in “A patient guide to brain stent placement” by Jill Novitzke (Journal of vascular intervention in neurology (J Vase Interv Neurol.) 2009 Apr; 2(2): 177-179). It is noted that in ISO 14117, the international organization of standardization (ISO) specifies test methodologies for the evaluation of the electromagnetic compatibility (EMC) of active implantable devices. Moreover, the temperature increase in the brain during medical procedures must not exceed about 2°C, as stated by regulatory agencies (such as ISO, the food and drug administration (FDA) and the like). As such, it is important to tightly control the illumination and the temperature in such procedures.

[0012] SUMMARY OF THE INVENTION

[0013] An embodiment of the present invention that is described herein provides a device implanted in an organ, the device including (a) an energy consuming device (ECD) configured to receive electrical power and to apply energy to the organ, and (b) a resonance circuit, which is configured to (i) receive a magnetic field (MF), and (ii) convert the MF to the electrical power, a resonance frequency of the resonance circuit depending on a temperature of the organ, and in response to a change in the temperature of the organ, the resonance circuit is configured to change an intensity of the electrical power supplied to the ECD.

[0014] In some embodiments, the device includes a MF source external to the organ and configured to generate the MF, the MF source: (a) includes an external inductor configured to generate the MF in response to receiving an electrical current, and (b) configured to (i) supply the electrical current to the external inductor, and (ii) sense a change in the supplied electrical current in response to the change in intensity of the electrical power supplied to the ECD. In other embodiments, the MF source is configured to supply the electrical current having a given frequency, and at a first temperature of the organ the resonance circuit has a first resonance frequency and configured to supply a first power to the ECD, and at a second temperature of the organ the resonance circuit has a second resonance frequency, different from the first resonance frequency, and configured to supply, to the ECD, a second power different from the first power. In yet other embodiments, the resonance circuit includes a capacitor and an inductor interconnected in parallel to one another, and at least one of (a) a capacitance of the capacitor, and (b) an inductance of the inductor is configured to change in response to altering temperature of the organ.

[0015] In some embodiments, in response to the altering temperature of the organ, the capacitor is configured to change the capacitance by changing a distance between conductors of the capacitor. In other embodiments, the capacitor includes a microelectromechanical (MEMS) device. In yet other embodiments, the inductor has a ferrite component configured to increase the induction of the inductor, and a permeability of the ferrite component depends on the temperature, and based on the ferrite component, the inductor is configured to change the inductance in response to the altering temperature of the organ.

[0016] In some embodiments, the device includes a subdermal MF source implanted between a scalp and the organ and configured to generate the MF, and the MF source: includes (i) an additional inductor configured to generate the MF in response to receiving an electrical current, and (ii) a power storage apparatus configured to supply the electrical current to the external inductor. In other embodiments, the ECD includes one or more light emitting diodes (EEDs), which are coated with a biocompatible material configured to electrically isolate between the one or more EEDs and tissue surrounding the one or more LEDs, and the one or more LEDs are configured to apply to the brain light in response to receiving the electrical power. In yet other embodiments, at least one of the LEDs is configured to produce a temperature signal indicative of the temperature of the organ.

[0017] In some embodiments, the device includes a processor that, in response to the sensed change in the supplied electrical current, is configured to produce a control signal indicative of the temperature of the organ. In other embodiments, the processor is configured to control the temperature of the organ in a closed loop based on one or more signals indicative of the temperature of the organ. In yet other embodiments, the organ includes a head of a patient, and the device is configured to be implanted in the head (i) between a scalp and a skull, or (ii) between the skull and a dura, for performing an optogenetic activation in a brain of the patient.

[0018] In some embodiments, the resonance circuit includes (a) a stent, which is shaped to be implemented in a blood vessel, and is configured to (i) receive the MF, and (ii) convert the MF to the electrical power, and (b) electrical leads for connecting between the stent and at least the ECD. In other embodiments, the stent includes an alloy of nickel-titanium, which is at least partially coated with a biocompatible material configured to electrically isolate between the stent and tissue surrounding the stent. In yet other embodiments, the stent includes (i) an electrically conductive wire, and (ii) a layer of polyether ether ketone (PEEK), which is coated over the electrically conductive wire and configured to electrically isolate between the electrically conductive wire and tissue surrounding the electrically conductive wire.

[0019] There is additionally provided, in accordance with an embodiment of the present invention, a method for fabricating a device intended to be implanted in an organ, the method including producing a resonance circuit, for (i) receiving a magnetic field (MF), and (ii) converting the MF to an electrical power, and a resonance frequency of the resonance circuit depends on a temperature of the organ. The resonance circuit is integrated with an energy consuming device (ECD) configured to receive the electrical power and to apply energy to the organ, and in response to a change in the temperature of the organ, the resonance circuit changes an intensity of the electrical power supplied to the ECD.

[0020] In some embodiments, producing the resonance circuit includes (i) producing at least a capacitor and an inductor, and at least one of (a) a capacitance of the capacitor, and (b) an inductance of the inductor, changes in response to altering temperature of the organ, and (ii) interconnecting the capacitor and the inductor in parallel to one another. In other embodiments, producing the inductor includes producing a stent having an electrically conducting coil coated with an electrically insulating layer. In yet other embodiments, the electrically conducting coil includes an alloy of nickel and titanium.

[0021] In some embodiments, the electrically insulating layer includes polyether ether ketone (PEEK). In other embodiments, producing the capacitor includes (i) connecting the ECD to an electrically conducting lead, (ii) positioning first and second edges of the electrically conducting lead at a predefined gap from one another, and (iii) disposing a dielectric layer in the gap between the first and second edges.

[0022] There is further provided, in accordance with an embodiment of the present invention, a method including, in a device implanted in an organ and having: (i) an energy consuming device (ECD) for applying energy to the organ in response to receiving electrical power, and (ii) a resonance circuit whose resonance frequency depends on a temperature of the organ, receiving a magnetic field (MF) from a MF source external to the organ. The MF is converted to the electrical power, and in response to a change in the temperature of the organ, changing an intensity of the electrical power supplied to the ECD. In some embodiments, the method includes in response to receiving a first signal indicative of a change in the supplied electrical current, produce a second signal indicative of the temperature of the organ. In other embodiments, implanting the device in the organ includes implanting the device in a head of a patient, (i) between a skin and a skull of the head, or (ii) between the skull and a dura of the head, and performing an optogenetic activation in a brain of the patient. In yet other embodiments, implanting the device including implanting: (a) the resonance circuit including a stent, which is shaped to be implemented in a blood vessel for receiving the MF and converting the MF to the electrical power, and (b) electrical leads for connecting between the stent and at least the ECD.

[0023] There is additionally provided, in accordance with an embodiment of the present invention, a subdermal pulse generating device, including: (a) an energy consuming device (ECD) configured to receive electrical power and to apply energy to the organ, (b) a power storage apparatus configured to supply the electrical power to the ECD, and (c) an antenna, which is configured to (i) receive a magnetic field (MF), and (ii) convert the MF to the electrical power for at least one of: (1) charging the power storage apparatus, and (2) supplying the electrical power to the ECD.

[0024] In some embodiments, the power storage apparatus includes one or more rechargeable batteries. In other embodiments, the antenna includes a first inductor, and including a MF source external to the organ and configured to generate the MF, and the MF source: (i) includes a second inductor configured to generate the MF in response to receiving an electrical current, and (ii) configured to supply the electrical current to the second inductor. In yet other embodiments, the MF source is implemented in a wearable clothing item.

[0025] In some embodiments, the MF source is implemented in bed linen. In other embodiments, the device includes a processor, which is configured to (i) sense a temperature of the organ, and (ii) control the electrical power supplied to the ECD in order to maintain the temperature within a predefined range.

[0026] In some embodiments, the processor is configured to produce a signal indicative of the sensed temperature of the organ, and to display the sensed temperature to a user over a display. In other embodiments, the organ includes a head, and at least the ECD, the power storage, and the antenna, are implanted between a skull and a scalp of the head.

[0027] The present invention will be more fully understood from the following detailed description of the embodiments thereof, taken together with the drawings in which: BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Fig. 1 is a block diagram that schematically illustrates a closed-loop control of an optogenetic activation, in accordance with an embodiment of the present invention;

[0029] Fig. 2 is a block diagram that schematically illustrates an induction-based thermal switch implemented in an implantable device and an external device used in the optogenetic illumination procedure of Fig. 1, in accordance with an embodiment of the present invention;

[0030] Figs. 3A and 3B are schematic, pictorial illustrates of stent-based implantable devices, in accordance with other embodiments of the present invention;

[0031] Figs. 4A and 4B are schematic pictorial illustrations of multiple implantable devices used in the optogenetic illumination procedure of Fig. 1, in accordance with several embodiments of the present invention;

[0032] Fig. 5A is a schematic, pictorial illustration of an implantable subdermal pulse generating device used in the optogenetic illumination procedure of Fig. 1, in accordance with an embodiment of the present invention;

[0033] Fig. 5B is a schematic, pictorial illustration of an implementation of subdermal pulse generating device of Fig. 5A, in accordance with another embodiment of the present invention;

[0034] Fig. 5C is a schematic, pictorial illustration of a charging device for transferring energy to the implanted devices of Figs. 3 A, 3B, 5 A and 5B, in accordance with another embodiment of the present invention;

[0035] Fig. 6 is a flow chart that schematically illustrates a method for performing optogenetic illumination with thermal protection and closed loop control, in accordance with an embodiment of the present invention; and

[0036] Fig. 7 is a flow chart that schematically illustrates a method for fabricating a stent-based implantable device used in the optogenetic illumination procedure of Fig. 1, in accordance with an embodiment of the present invention.

[0037] DETAILED DESCRIPTION OF EMBODIMENTS

[0038] OVERVIEW

[0039] Some neurological conditions are characterized by abnormal activity of neurons (nerve cells), such is the case in epileptic seizures, Parkinson's disease, neuropathic pain, and other syndromes. Neuronal activity is generated by electrochemical changes on the surface of neurons, which, in turn, leads to an electric current known in the art as an action potential. Voltage-gated ion channels located on the membrane of the nerve cell mediate the passage of ions through the membrane, creating a shift in the electric potential that travels along an axon of the neuron to a presynaptic terminal of the neuron. At the synapse (a small gap between neurons), the opening of calcium channels triggers the release of neurotransmitters (chemical substances that mediate activity in the receiving neuron), which bind to receptors on neighboring neurons and either excite or inhibit their activity.

[0040] Some methods of treating neurological syndromes rely commonly on medications that nonspecifically affect the whole brain (including other organs, as part of its systemic effect). In some cases (such as in 30% of epilepsy cases) medications fail to produce the required effect, or produce adverse effects which may seriously impair quality of life for the patient. Another treatment technique includes electrical stimulation using implanted electrodes to administer electrical impulses to specific areas of the brain. This technique offers improved precision and efficacy over the aforementioned medication, but still lacks precise spatial control because this technique cannot discern between different types of cells in the area receiving the electrical stimulation pulse(s). More specifically, this technique cannot discern between different types mostly due to stimulation of white matter axons in the vicinity of the actual target, as well as induce excitatory and inhibitory neurons without discerning.

[0041] Another technique, referred to herein as optogenetics, allows a spatiotemporally precise modulation of selected neurons by inserting genes which, in turn, lead to the expression of opsins (light-sensitive proteins) on the selected cells membrane. These opsins are activated by light and control neuronal activity through endogenous cellular mechanisms. These opsins, change their structure when exposed to light of a certain wavelength, causing the opening of ion channels in the membrane and the passage of specific ions into the cell or in the case of G-protein-coupled receptor (GPCR) opsins, the activation of endogenous GPCR intracellular cascades.

[0042] The improved spatiotemporal precision capabilities or optogenetics (compared to that of the electrode-based electrical stimulation, and chemical drugs) enables the development of treatments for neurological diseases in a precise manner while lowering adverse effects profiles. The light penetration profile of red light enables the possibility to develop these treatments in a minimally invasive manner, and in large brains, such as humas brain.

[0043] An embodiment of the present invention that is described herein-below provides a combination of opsins expressed in a relevant brain area including the brain’s cortex or deep structures (e.g. thalamus, hippocampus, basal ganglia, and others), and an optical illumination device to carry out the treatment. In some embodiments, the optical illumination device is implanted superficially, for example, between the patient's skull and dura, in a minimally invasive procedure. In other embodiments, the optical illumination device is implanted deeper, using any suitable technique, such as the techniques used for implanting deep brain stimulation electrodes, or intravascular intervention techniques.

[0044] In some embodiments, the implanted device is configured to emit light in one or more suitable wavelengths (e.g., wavelengths between about 430 nm and 750 nm), so as to activate the opsins in a closer or farther than the location of optrodes (optical electrodes - e.g., devices designed to deliver light and collect fluorescence using a monolithic fiber electrode) depending on the application requirements, and the related neurological indication treatment protocol. It is noted that implanting the device externally to the dura mater (e.g., using a minimally invasive technique) reduces risks of complications associated with intracranial surgery, such as intracranial bleeding and infection, and migration and / or breakage of one or more electrodes.

[0045] In order to prevent tissue damage, activation of implanted devices requires a strict range of temperatures. More specifically, the temperature increase caused by implanted devices must not exceed about 2°C, as stated by regulatory agencies [ISO 14117]. Some illumination techniques, such as photobiomodulation therapy effect, are associated with light flux. In some embodiments of the present invention, in order to maximize light output while maintaining temperature increase within the aforementioned 2°C limit, the implanted device has a continuous, digital temperature measurement. Embodiments of the present invention disclose various techniques for controlling the temperature in the above-described treatment, and are depicted in detail, at least in Figs. 2-6 below.

[0046] In some embodiments, the disclosed techniques enable minimizing intensities of illumination, which is sufficient for activating GPCR bistable opsins, such as but not limited to eOPN3 cited, for example, in U.S. Patent Application Publication 2021 / 0403518 to Yizhar et al., whose disclosure is incorporated by reference. As such, the disclosed techniques reduce power consumption and prevent tissue overheating. In an embodiment, the implanted device is configured to apply heat cut-off techniques instead of heat measurements. Such heat cut-off techniques provide the medical staff and the patient with a simple, small, and reliable apparatus compared to that of a code -based digital measurements. Example implementations of such techniques are depicted in detail in Figs. 2, 3A and 3B below. Moreover, such techniques may be implemented for treating several areas in the brain located at various respective distances from the skull (e.g., in superficial or deep tissue of the brain). In some embodiments, the implanted device comprises an array of light-emitting diodes (LEDs) each of which configured to illuminate a respective area in the brain with a predefined wavelength suitable for (i) the required depth of the treated area, and (ii) predefined wavelength(s) to obtain an effective treatment, e.g., by inhibition through the endogenous GPCR pathways. In some embodiments, during the optogenetic activation, a processor of the device is configured to address different signals to different respective LEDs, so as to treat different areas at different depths of the brain. Implementations of these techniques are described in detail in Figs. 4A and 4B below.

[0047] In some embodiments, the implanted device may comprise a pulse generator comprising (i) a control unit (e.g., a processor having temperature measurement capabilities), (ii) one or more LEDs, (iii) an antenna configured to receive a magnetic field (MF) from an external charging device, and to convert the MF to electrical power intended to be supplied to the LEDs, and (iv) a power storage device, such as one or more suitable rechargeable batteries, configured to receive the power from the antenna and to supply the power to the one or more LEDs. Moreover, the external charging device may be implemented in an item of clothing (e.g., a hat) worn by the patient, in a bed linen (for charging while the patient is sleeping), or in any other suitable type of apparatus. The external charging device comprises power supply and an antenna for wirelessly conveying the energy to the aforementioned antenna of the implanted device. The external antenna may be implemented, for example, using an inductor configured to receive electrical current from the power supply, and convert the electrical current to the MF transmitted to the internal antenna of the implanted device. The implanted device and the external charging device are described in detail in Figs. 5A, 5B and 5C below.

[0048] This disclosed techniques may be applied to reduce time and costs associated with surgical operations. Controlling the illumination wavelength (e.g., red light) enable controllable penetration factor in biological tissue, and reducing the size of the implanted device. For example, in order to maximize efficacy, and obtain reduced invasiveness profile, the device may be applied to illuminate sensitive opsins which are reactive to wavelengths longer than 530 nm.

[0049] SYSTEM DESCRIPTION

[0050] Fig. 1 is a block diagram that schematically illustrates a system 10 used to perform a closed-loop control of an optogenetic activation, in accordance with an embodiment of the present invention.

[0051] In some embodiments, the optogenetic activation whose essence are described in the overview section above, is carried out using system 10, typically having an implantable device and an external device. Several implementations of the implantable and external devices are described in detail in Figs. 2-5C below.

[0052] In some embodiments, system 10 comprises electroencephalogram (EEG) electrodes 12 configured to measure electrical activity in a brain 7 of a patient 9 using small (e.g., about 10 mm), metal discs attached to the scalp of patient 9 shown in an inset 8 presenting a sectional view of tissues surrounding the brain 7 of patient 9. In other embodiments, the device is implanted between the skull and the dura matter and comprises smaller discs (e.g., having a diameter smaller than about 5mm). system 10 further comprises an amplifier 14 configured to amplify the signals received from electrodes 12, and a processor 11 configured to receive the amplified signals and to control a light stimulation device 16, also referred to herein as a device 16, for brevity. Several implementations of device 16 and processor 11 are described in detail in Figs. 2-5C below.

[0053] Typically, processor 11 comprises an application- specific integrated circuit (ASIC) device, which is customized to carry out the functions described herein. The configuration may be downloaded to the computer in electronic form, over a network, for example, or it may, alternatively or additionally, be provided and / or stored on non-transitory tangible media, such as magnetic, optical, or electronic memory connected to an inductive programmer.

[0054] Fig. 2 is a block diagram that schematically illustrates an induction-based thermal switch implemented in an implantable device 22, and an external device 33, in accordance with an embodiment of the present invention.

[0055] Implantable device 22 and external device 33 are also referred to herein for brevity as device 22 and device 33, respectively. Devices 22 and 33 may replace, for example, device 16 and processor 11 of Fig. 1 above, and may be used in the optogenetic illumination procedure of Fig. 1.

[0056] In some embodiments, device 33 is external to the head of patient 9, and device 22 may be implanted in patient 9, e.g., (i) between the skin and scalp, or (ii) between the scalp and skull, or (iii) between the skull and the dura mater or in deeper tissue such as blood vessels), as described in Figs. 3 A and 3B. In the present example, device 33 comprises processor 11, a current meter referred to herein as an amperemeter 18, configured to measure the current flowing in device 33, and an inductor implemented in an inductive coil 20. Device 22 comprises an energy consuming device (ECD), in the present example at least one light-emitting diode (LED) 44 configured to receive electrical power and to emit optical illumination directed into the brain 7 of patient 9. In other embodiments, instead of LED 44, device 22 may comprise any other suitable type of ECD configured to apply energy to brain 7 or to any other organ of patient 9 (in another medical procedure).

[0057] In some embodiments, device 22 comprises a resonance circuit 21, which is configured to (i) receive a magnetic field (MF) from coil 22, and (ii) convert the MF to the electrical power used for operating LED 44. In the present example, resonance circuit 21 comprises a capacitor 23 and an inductive coil 24, also referred to herein as an inductor 24 interconnected in parallel to one another using electrical leads 27. In some embodiments, in response to receiving the MF, coil 24 is configured to induce electrical current for generating the aforementioned electrical power. LED 44 and resonance circuit 21 are electrically connected to one another using leads 27. Moreover, at least one of and typically all the components of device 22 may be implemented on a circuit board (CB) 29, which is biocompatible or being coated using a suitable biocompatible coating material (e.g., a polycyclic aromatic hydrocarbon with the chemical formula C20H12, also referred to herein as perylene).

[0058] As described in the overview section above, in order to prevent damage to brain 7, the temperature increase that is typically caused by the operation of implanted device 22 (e.g., by the illumination by the LED(s) 44), must not exceed about 2°C. Thus, it is very important to control the temperature in brain 7 by controlling the illumination of LED 44. In some embodiments, capacitor 23 and inductor 24 are selected such that at least one of (a) the capacitance of capacitor 23, and (b) the inductance of inductor 24 is configured to by altered in response to changes in the temperature in brain 7. In such embodiments, the resonance frequency of resonance circuit 21 depends on the temperature of brain 7.

[0059] In some embodiments, the frequency of the signal (e.g., MF) received from device 33 is adjusted to the regular temperature of patient 9 (e.g., about 37oC). It is noted that inductive coupling requires a resonance between inductor 24 and capacitor 23. To increase the efficiency of the coupling, the Q factor (which is a dimensionless parameter describing how underdamped is the resonance) of resonance circuit 21 is chosen to be high. As such, a resonance frequency 25 of resonance circuit 21 is adjusted to harvest the maximal energy by device 22 at the regular temperature of brain 7, e.g., at about 37 oC. In the present example, the capacitance of capacitor 23 alters with the temperature due to changes in the dielectric coefficients of the material of capacitor 23, and due to mechanical changes in the conductors of capacitor 23. In order to increase the temperature coefficient in a controllable manner the capacitor is produced using a microelectromechanical (MEMS) process. In the MEMS-based capacitor 23, any change in the temperature of brain 6, results in a change in the distance between conductive layers capacitor 23, and thereby, varies the capacitance of capacitor 23.

[0060] Additionally, or alternatively, device 22 comprises a ferrite element 26, which is integrated with inductor 24 and is configured to increase the inductance of inductor 24. It is noted that the permeability of the ferrite element 26 changes with temperature, thus, the inductance of inductor 24 also changes in response to changes in the temperature of brain 7. In some embodiments, in response to a change in the temperature of brain 7, the resonance frequency 25 of resonance circuit 21 is being altered, for example, an increase in temperature shifts the resonance frequency 25. In this configuration, resonance circuit 21 is configured to function as a negative feedback, so that in response to an increase in the temperature of brain 7, the resonance frequency 25 of resonance circuit 21 shifts to reduce the intensity of the energy received by device 22. In such embodiments, device 22 is configured to receive a smaller portion of the energy of the MF received from device 33. This results in reducing the intensity of the electrical power supplied from device 33, via resonance circuit 21, to LED 44.

[0061] In some embodiments, processor 11 is configured to generate electrical current supplied to coil 20, which is configured to generate the MF inducted to inductor 24 of device 22. It is noted that in response to the increased temperature of brain 7, the reduced amount of energy consumed by device 22 results in a reduced consumption of current, which is measured by amperemeter 18. In such embodiments, processor 11 is configured to reduce the electrical current supplied to coil 20, so as to adjust the illumination level by LED 44, and hereby, reduce the temperature of brain 7 back to about 37 oC.

[0062] Additionally, or alternatively, the diode of LED 44 is configured to measure the temperature in brain 7, and the measured temperature is conveyed to processor 11 for controlling the electrical current supplied to coil 20, so as to control the temperature in brain 7.

[0063] In some embodiments, based on at least one of: (i) the temperature-dependence of resonance frequency 25, (ii) the temperature measurement by the diode of LED 44, as well as the sensed level of electrical current (e.g., by amperemeter 18), processor 11 is configured to control the illumination level in closed loop, and thereby, to control the temperature in brain 7 in closed loop. Moreover, processor 11 is configured to generate a signal indicative of the changes in electrical current draw. So as to prevent overheating in brain 7, and to generate an alarm (e.g., by displaying over a display, or using any other alarming technique) to the user of devices 22 and 33.

[0064] In some embodiments, based on the temperature dependence of resonance frequency 25, resonance circuit 21 is configured to serve as an inherent dimmer of the power supplied to LED 44.

[0065] Figs. 3 A and 3B are schematic, pictorial illustrates of stent-based implantable devices 31 and 32, in accordance with embodiments of the present invention. Each of stent-based implantable devices 31 and 32 are also referred to herein as devices 31 and 32, for brevity, and these devices may replace, for example, device 22 of Fig. 2 above, and / or device 16 of Fig. 1 above.

[0066] Reference is now made to Fig. 3A. In some embodiments, devices 31 comprises an inductive coil 34 (that also serves as an antenna, as described in the overview above) and a ferrite element 36 having a functionality similar to that of respective coil 24 and ferrite element 26 of Fig. 2 above. In the present implementation example, coil 34 comprises a stent made from an alloy of nickel and titanium (e.g., with a near-equiatomic composition (i.e., 49%-51%) of nickel and titanium, respectively), also referred to as nitinol. It is noted that nitinol-based stents, which are biocompatible, are used broadly in medical procedures and have mature fabrication processes.

[0067] In some embodiments, nitinol has a shape memory, which is the ability of nitinol to undergo deformation at a given temperature, and gain elasticity to inspire to the deformed shape.

[0068] In such embodiments, the stent is configured to fit in a blood vessel (e.g., in the head) of patient 9. More specifically, coil 34 is configured to collapse for being implanted using a minimally invasive procedure known in the art, and expand to a predesigned structure to hold onto a selected cavity (e.g., the aforementioned blood vessel) within the head of patient 9. In the present example, the electrical conductivity of coil 34 is about 100 micro-ohms per cm. As described in Fig. 2 above, the power required to operate LED 44 is received wirelessly by inductance, as such, no battery or any other energy storage device is needed, so as to simplify the structure of implantable device 31.

[0069] In some embodiments, device 31 comprises capacitor 23 and at least one LED 44 connected in parallel to one another, and connected to coil 34 using leads 27. Additionally, or alternatively, capacitor 23 and the at least one LED 44 may be mounted on a biocompatible CB 39 (e.g., a CB coated with biocompatible material, such as perylene) and are electrically connected using leads 27 or traces implemented in CB 39. Coil 34 is coupled with leads 27 using any suitable technique, such as but not limited to laser welding.

[0070] In some embodiments, coil 34 is coated with a biocompatible and electrically insulating material disposed over the outer surface of coil 34 using a suitable coating (e.g., perylene). The structure of ferrite element 36 may be similar to that of ferrite element 26 of Fig. 2 above, or may have any other suitable size and shape to fit into the geometrical limitations of the stent. In the present implementation, the edges of coil 34 are electrically connected (e.g., using leads 27) to ferrite element 36 and CB 39. In some embodiments, the induction receiving antenna implemented in coil 34 is designed to be integrated into the stent, so as to reduce the overall size of coil 34. The stent of coil 34 is formed in a shape fitting to the blood vessel, and is implanted in the blood vessel to prevent detachment, but coil 34 is not required (and / or configured) to apply force to open the blood vessel.

[0071] In some embodiments, in addition to or instead of ferrite element 36, the blood flowing through the aforementioned blood vessel of patient 9, may be taken into consideration as a ferrite material for increasing the inductive of the antenna implemented in coil 34, and thereby enables a reduction in the size of coil 34 and increasing the Q factor thereof.

[0072] Reference is now made to Fig. 3B showing device 32, which is another implementation of a stent-based coil 35 with LEDs 44 and capacitor 23 in accordance with an embodiment of the present invention. In some embodiments, device 32 comprises a CB 49 having multiple LEDs 44 and capacitor 23, which are mounted on CB 49 and are interconnected using traces 38 of CB 49. In this configuration, CB 49 is electrically connected with edges 41 of coil 35 using traces 38 (and / or leads 27 shown in Fig. 3A above).

[0073] In some embodiments, coil 35 has a shape other than cylindrically symmetrical to control the spread and directing of the light beams generated by LEDs 44.

[0074] In some embodiments, both coils 34 and 35 (of Figs. 3A and 3B, respectively) have radio-opaque markings that could be used by a physician for guiding and implanting the stent into the intended position of the stent within the head of patient 9. In some embodiments, multiple stent-based devices, such as device 32 (and / or device 31), may be implanted in the head of patient 9, as will be described in detail in Figs. 4A and 4B below. In an embodiment, each device 32 may by operated using a different operating frequency to enable illumination control. In another embodiment, multiple devices (such as device) 32 may be operated using the same operational frequency to enable an increased illumination and area being illuminated by LEDs 44.

[0075] In some embodiments, both implantable devices 31 and 32 are configured to receive energy from an external device, such as device 33, as shown and described in detail in Fig. 2 above. In the example of Fig. 2, device 33 is completely external to the body of patient 9. In other embodiments, (in addition to or) instead of device 33, the energy-supplying device may be implanted in the skull of patient 9. In alternative embodiments, the energy-supplying device may be implanted between the patient's skull and skin of patient 9.

[0076] In some embodiments, the energy- supplying device may comprise sensors such as but not limited to EEG electrodes 12 (shown in Fig. 1 above), MEMS accelerometers, such as the ADXL358 product, supplied by Analog Devices Inc. (One Analog Way, Wilmington, MA 01887), configured to adjust stimulation in different positions of patients (e.g., standing, sitting, laying), and gyroscopes, such as the ADXRS290 product, also supplied by Analog Devices, configured to adjust to movements of the patient (e.g., tremors, falls, and head tilts). These devices are further configured to produce respective signals that processor 11 could use as input for an algorithm to decide (i) whether or not to supply wireless energy to any of devices 16, 22, 31, and 32, of Figs. 1, 2, 3A and 3B, respectively, and (ii) the amount of energy (e.g., the intensity of the magnetic field) required to be wirelessly sent to the implanted device for performing the required level of illumination (by LEDs 44) to obtain the required medical effect in treating brain 7 of patient 9.

[0077] In other embodiments, instead of the coated nitinol described above, at least one stent of coils 34 and 35 comprises (i) an electrically conductive wire (e.g., shown as trace 38 in Fig. 3B), and (ii) a layer of poly ether ether ketone (PEEK), which is coated over the electrically conductive wire, and is configured to electrically isolate between the electrically conductive wire and tissue, such as the blood vessel, surrounding the electrically conductive wire. PEEK is biocompatible and has memory shape attributes similar (but typically not identical) to that of nitinol, so that the combination of the electrically conductive wire and the PEEK coating, can be used in at least one of coils 34 and 35. Moreover, PEEK has high electrical resistivity (larger than about 5x1016 ohm per cm) to prevent undesired leakage of electrical current along the stent, and the PEEK coating is typically produced using an injection molding process.

[0078] In some embodiments, the fabrication of the PEEK-based stent of coil 34 and / or 35 comprises first and second process operations. In the first operation, the electrically conductive wire is formed in the shape of the stent-based antenna, and configured for receiving the energy from energy- supplying device 33, and wiring to connect LEDs 44 and capacitor 23 together. In some embodiments, the connection with LEDs 44 and capacitor 23 is carried out in a wafer level to reduce the size of the respective implantable device (e.g., device 31 and / or device 32) and to enable mass production of the PEEK-based implantable device.

[0079] In some embodiments, in the first operation, capacitor 23 is fabricated utilizing the mechanical properties of the material used in the electrically conductive wire. In an embodiment shown in Fig. 3B above, the electrodes of capacitor 23 are formed from the edges 37 of the electrically conductive wire (e.g., trace 38 in Fig. 3B), and capacitor 23 is formed by inserting (disposing) PEEK between edges 37 of trace 38. This fabrication technique reduces the size and simplifies the structure (by reducing the number of components) of the implantable device (such as device 32). Moreover, this fabrication technique simplifies the fabrication costs of the implantable device, by fabricating capacitor 23 together with the coil connecting LEDs 44. In some embodiments, the antenna design of the implantable device (e.g., device 32) does not require a ferrite element and uses the blood surrounding coil 35 instead of the ferrite element. In some embodiments, this implementation is applied to reduce the size of the stent-based antenna, and to increase the Q factor of coil 35.

[0080] In some embodiments, in the second operation, the electrically conductive wire (e.g., instead of race 38) is placed in a mold and coated with injected PEEK, so as to obtain the required mechanical properties of the stent of coil 35. It is noted that PEEK is not absorbing the wavelengths (e.g., higher than about 530 nm) of the light generated by LEDs 44. Thus, most of the light emitted by LEDs 44 is used for performing the optogenetic activation.

[0081] In some embodiments, the stent of coil 35 may be formed using a heat shaping process on a pre-made mix of pure PEEK and PEEK engulfed wires, so as to fabricate the antenna to obtain the required shape. As also described above, in some embodiments, the shape of coil 35 must be other than cylindrically symmetric, so as to enable the control of light spread and direction toward brain 7. Moreover, coil 35 may comprise radio-opaque markings that could be used by a physician for guiding and implanting the stent (implemented in coil 35) into the intended position of the stent within the predefined blood vessel of patient 9, as also described above.

[0082] In some embodiments, multiple stent-based devices, such as device 32, may be implanted in the head of patient 9, as will be described in detail in Figs. 4A and 4B below. In an embodiment, each device 32 may by operated using a different operating frequency to enable illumination control. In another embodiment, multiple devices 32 may be operated using the same operational frequency to enable an increased illumination and area being illuminated by LEDs 44.

[0083] In some embodiments, both implantable device 32 is configured to receive energy from an external device, such as device 33 shown and described in detail in Fig. 2 above. In the example of Fig. 2, device 33 is completely external to the body of patient 9. In other embodiments, (in addition to or) instead of device 33, the energy-supplying device may be implanted in the skull of patient 9. In alternative embodiments, the energy-supplying device may be implanted between the patient's skull and skin of patient 9.

[0084] In some embodiments, the energy- supplying device (e.g., device 33) and / or implantable device 32 may comprise sensors such as but not limited to EEG electrodes 12 (shown in Fig. 1 above), MEMS accelerometers, such as the aforementioned ADXL358 product, configured to adjust stimulation in different positions of patients (e.g., standing, sitting, laying), and gyroscopes, such as the aforementioned ADXRS290 product, also supplied by Analog Devices, configured to adjust to movements of the patient (e.g., tremors, falls, head tilts). These devices are configured to produce respective signals that processor 11 could use as input for an algorithm to decide (i) whether or not to supply wireless energy to device 32, and (ii) the amount of energy (e.g., the intensity of the magnetic field) required to be wirelessly sent to device 32 for performing the required level of illumination (by LEDs 44) to obtain the required medical effect in treating brain 7 of patient 9.

[0085] These particular configurations of devices 33, 22, 31 and 32 of Figs. 2, 3A and 3B, are shown by way of example, in order to illustrate certain problems that are addressed by embodiments of the present invention and to demonstrate the application of these embodiments in enhancing the performance of such a system (e.g., system 10 of Fig. 1 above) for performing brain-treatment procedures using closed-loop control as described above. Embodiments of the present invention, however, are by no means limited to this specific sort of example devices and / or system 10, and the principles described herein may similarly be applied to other sorts of systems that may be used in optogenetic activations.

[0086] Figs. 4A and 4B are schematic pictorial illustrations of multiple implantable devices 55a and 55b used in the optogenetic illumination procedure of Fig. 1, in accordance with several embodiments of the present invention.

[0087] In some cases, the optogenetic activation requires activation and / or inhibition in multiple treatment areas in brain 7. At least two of the treatment areas may be located at different depths within the skull of patient 9. It is noted that longer wavelengths (e.g., 625 nm) penetrate tissue deeper than shorter wavelengths (e.g., 530 nm).

[0088] In some cases, the optogenetic activation requires post-implantation control over which LEDs are turned on. Moreover, the required control could be specific per patient, per treatment or per time. As such, performing the control using separate control wires per LED or per region could increase resistance path, reduce device reliability, increase the size, or increase the complexity of fabricating such an illumination system.

[0089] In some embodiments, multiple illumination devices 55a and 55b are implanted in the head of patient 9 using systems 50 and 56 of Figs. 4A and 4B, respectively. At least one of devices 55a and 55b may be similar to any of devices 22, 31, and 32 of the above Figs. 2, 3A and 3B, respectively.

[0090] In some embodiments, each of systems 50 and 56 comprises processor 11 configured to control the illumination of devices 55a and 55b implanted at several locations at the head of patient 9 in order to illuminate respective areas at brain 7. In order to apply the light differentially, for example, to different areas at different times, processor 11 is configured to generate control signals for activating devices 55a and 55b. Reference is now made to Fig. 4A. In some embodiments, system 50 comprises bandpass filters 53 implemented using any suitable sort of RLC circuits. In the present example, the band-pass filter is implemented using a capacitor 52 and an inductor 54 interconnected serially, or using any other suitable configuration. The properties of capacitor 52 and inductor 54 are selected to obtain the requested band-pass filter. In some embodiments, the control signals have different frequencies for activating each device 55 or a group of multiple devices 55 at the same time. In such embodiments, processor 11 is configured to activate different devices 55 at different times.

[0091] It is noted that the penetration depth of light depends on the wavelength of the light. In the present example, the maximal response (to light) of the light-sensitive proteins implemented in brain 7, is obtained at a wavelength of about 527 nm, and about 50% of the response (which is sufficient to carry out the procedure) is obtained at a wavelength of about 630 nm.

[0092] In an example implementation, devices 55a and 55b comprise different LEDs 44a and 44b, respectively, which are configured to emit different wavelengths of light, e.g., 527 nm, and 620 nm, respectively. It is noted that in some cases there could be a tradeoff between the efficacy and the depth of the illumination. For example, the 527 nm wavelength has the maximal efficacy but shallow penetration depth, and 700 nm could penetrate to any location in brain 7, but the illumination has low effect on the light-sensitive protein used in the present example. In this implementation, processor 11 is configured to activate (i) devices 55a to carry out the procedure in superficial areas located in close proximity to the skull, and (ii) devices 55b to carry out the procedure in areas deeper in the skull.

[0093] In another example implementation, devices 55a and 55b comprise similar LEDs 44a and 44b, configured to emit the same wavelengths of light, e.g., 630 nm, but are required to be activated at different times. Moreover, devices 55a and 55b have different band-pass filters 53. In this implementation, processor 11 is configured to activate (i) devices 55a to carry out the procedure at a first-time interval using a first control signal having a first frequency, and (ii) devices 55b to carry out the procedure a second-time interval, different from the first-time interval, by using a second control signal having a second frequency different from the first frequency. As such, the differential activation of devices 55a and 55b is carried out using analog techniques implemented in the band-pass filers 53 described above.

[0094] Reference is now made to Fig. 4B. In some embodiments, the devices 55a and 55b are similar to that presented in Fig. 4A above, but the activation is carried out using digital techniques. In some embodiments, each device among devices 55a and 55b has a predefined address, and processor 11 is configured to address the activation signal to each specific device to carry out the procedure at different times, different locations, and at different depth within the skull of patient 9, as described in detail in Fig. 4A above. In the present example, the example of Fig. 4B, the addressing is implemented in software, and using a diode 57, a switch 59, and a hold-up capacitor 58.

[0095] In some embodiments, the techniques described in Figs. 4A and 4B above reduce the number of components (e.g., processors, wiring, antennas, and more) implanted in the head of patient 9. Moreover, devices 55a and 55b of each of systems 50 and 56 receive energy wirelessly from an external device, such as device 33 whose structure and functionality are described in detail in Fig. 2 above.

[0096] Fig. 5A is a schematic, pictorial illustration of an implantable subdermal pulse generating device, referred to herein as a device 60, used in the optogenetic illumination procedure of Fig. 1, in accordance with an embodiment of the present invention. In the present example, device 60 is implanted between the skin and the skull of the head of patient 9.

[0097] In some embodiments, device 60 comprises a pulse generator comprising (i) a control unit 62, such as processor 11 of Figs. 1-4B above, and (ii) one or more light-emitting devices, such as one or more LEDs 44 of Figs. 1-4B above. In some embodiments, processor 11 comprises temperature-sensing circuitry configured to generate a signal indicative of the temperature at an area in brain 7, which is in proximity to processor 11.

[0098] In some embodiments, device 60 comprises an antenna 61 (such as inductor 24, and stent-based coils 34 and 35 of Figs. 2, 3A and 3B above, respectively), which is configured to receive the magnetic field from an external charging device (such as a device described in Fig. 5C below, or device 33 shown in Fig. 2 above), and to convert the magnetic field to electrical power intended to be supplied to LEDs 44.

[0099] In some embodiments, device 60 further comprises a power storage device 63, such as a pack of rechargeable batteries, configured to receive the power from antenna 61 and to supply the power to the one or more LEDs 44, as described in detail, for example in Fig. 2 above. In some embodiments, the one or more batteries comprise one or more medical grade solid state batteries. Such batteries are configured to carry about 50 micro -ampere-hour (uAH) per cell, and have a size of about 10 mm, 4 mm, and 0.6 mm in XYZ dimensions. For example, the solid- state battery may be implemented using a Stereax® M50 product supplied by Ilika Technologies Ltd (Southampton SO16 7NS, UK), and having a footprint of 10.75 mm by 3.75 mm, and a thickness of about 0.6 mm.

[0100] It is noted that the human scalp of an adult has a surface area larger than about 500 cm2, which can easily incorporate the size of power storage device 63. Moreover, typically, a deep brain stimulator (DBS) requires a battery having the capacity of about 200 mAH, which is sufficient for operating the DBS for about 30 days. In some embodiments, power storage device 63 is configured to connect multiple batteries in parallel, and thereby, has sufficient capacity to power device 60 to operate for more than two full days. Moreover, power storage device 63 is configured to be rechargeable wirelessly, as described in Fig. 2 above.

[0101] Fig. 5B is a schematic, pictorial illustration of an implementation of subdermal pulse generating device 60 of Fig. 5A, in accordance with another embodiment of the present invention. In the present example, device 60 comprises a biocompatible package 64 configured to contain control unit 62, and power storage device 63. Moreover, antenna 61 is extended from package 64 along the perimeter of the surface of the skull, and both package 64 and antenna 61 are implanted over the surface of the skull of patient 9.

[0102] Fig. 5C is a schematic, pictorial illustration of a charging device 66 for transferring energy to implanted device 60 shown in Figs. 5A and 5B above, in accordance with another embodiment of the present invention.

[0103] In some embodiments, the external charging device 66 may be implemented in an item of clothing, in the present example, in a hat 68 worn by patient 9. In the present implementation, external charging device 66 comprises power supply implemented in a rechargeable battery 67, and an antenna 69, which is extended from battery 67 for wirelessly supplying the energy (e.g., over a magnetic field as described in detail in Fig. 2 above, or using any other suitable technique), to antenna 61 of implanted device 60.

[0104] In some embodiments, antenna 69 of device 66 may be implemented, for example, using an inductor configured to (i) receive electrical current from rechargeable battery 67, and (ii) convert the electrical current to the magnetic field transmitted to antenna 61 of implanted device 60.

[0105] In alternative embodiments, device 66 may be implemented in a bed linen for charging power storage device 63 while patient 9 is sleeping, or in any other suitable type of apparatus which is placed in contact with the head of patient 9.

[0106] These particular configurations of devices 60 and 66 of Figs. 5A-5C, are shown by way of example, in order to illustrate certain problems that are addressed by embodiments of the present invention and to demonstrate the application of these embodiments in enhancing the performance of a system for performing brain-treatment procedures using closed-loop control as described in the example of system 10 of Fig. 1 above. Embodiments of the present invention, however, are by no means limited to this specific sort of example configurations, and the principles described herein may similarly be applied to other sorts of implanted devices and charging devices that may be used in optogenetic activations and may have any suitable arrangement of the components described above, or other components configured to perform the operations described in Figs. 1-5C above.

[0107] Fig. 6 is a flow chart that schematically illustrates a method for performing optogenetic illumination with thermal protection and closed loop control, in accordance with an embodiment of the present invention.

[0108] In some embodiments, the method of Fig. 6 is implemented using devices 22 and 33 of Fig. 2 above, but the method may be implemented, mutatis mutandis, using any of the devices shown in Figs. 1-5C above.

[0109] The method begins at a device implanting step 100, with implanting in the head of patient 9, device 22 having LED 44, and resonance circuit 21 having capacitor 23 and inductor 24, wherein the resonance frequency 25 of resonance circuit 21 depends on the temperature of brain 7, as described in detail in Figs. 1 and 2 above.

[0110] At a power generating step 102, receiving the MF from coil 20 of device 33, converting the MF to the electrical power, and supplying, as described in detail in Fig. 2 above.

[0111] At a temperature controlling step that concludes the method, in response to sensing a change in the brain temperature (e.g., by sensing reduced consumption of electrical current by amperemeter 18 of device 33), the processor 11 is configured to change the intensity of the electrical current supplied to coil 20, resulting in reduced MF supplied to device 22, and therefore, reduced power supplied to LED 44, as described in detail in Fig. 2 above.

[0112] Fig. 7 is a flow chart that schematically illustrates a method for fabricating a stent-based implantable device 32, used in the optogenetic illumination procedure of Fig. 1, in accordance with an embodiment of the present invention.

[0113] The method begins at a stent production step 200, with producing stent-based coil 35 configured to be implanted in blood vessel, as described in detail in Fig. 3B above. In the present example, coil 35 comprises nitinol, but in another example coil 35 may comprise any suitable type of electrically conductive wire, as described in Fig. 3B above.

[0114] At a coating step 202, (i) at least a portion of the nitinol-based coil 35 is coated with a biocompatible and electrically insulating layer disposed over the outer surface of coil 35, using a suitable galvanized coating (e.g., perylene), or alternatively, (ii) a PEEK is coated over the electrically conductive wire of coil 35 for electrically insulating between the electrically conductive wire and the blood vessel surrounding the electrically conductive wire, as described in detail in Figs. 3A and 3B above. At an LED connecting step 204, one or more LEDs 44 are connected to and along any suitable type of electrical lead (e.g., electrical trace 38 of CB 49), as described in detail in Fig. 3B above.

[0115] At a capacitor formation step 206, capacitor 23 of device 32 is formed by positioning edges 37 of the electrically conducting lead (e.g., electrical trace 38) at a predefined gap from one another, and disposing dielectric layer (e.g., made from PEEK) in the gap, as described in detail in Fig. 3B above.

[0116] At a stent and lead connecting step 208 that concludes the method, the edges 41 of coil 35 are electrically coupled with the electrical lead, in the present example, with electrical trace 38 of CB 49, as described in detail in Fig. 3B above.

[0117] Although the embodiments described herein mainly address techniques for treating Parkinson’s disease, Epilepsy, Neuropathic pain, and other neurological diseases and / or disorders using optogenetic illumination with thermal protection and closed loop control, the methods and systems described herein can also be used in other applications, such as in electrical stimulation suitable for treating Parkinson’s disease, Epilepsy, Neuropathic pain, and other types of neurological diseases and / or disorders.

[0118] It will thus be appreciated that the embodiments described above are cited by way of example, and that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and sub-combinations of the various features described hereinabove, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art. Documents incorporated by reference in the present patent application are to be considered an integral part of the application except that to the extent any terms are defined in these incorporated documents in a manner that conflicts with the definitions made explicitly or implicitly in the present specification, only the definitions in the present specification should be considered.

Claims

CLAIMS1. A device implanted in an organ, the device comprising: an energy consuming device (ECD) configured to receive electrical power and to apply energy to the organ; and a resonance circuit, which is configured to (i) receive a magnetic field (MF), and (ii) convert the MF to the electrical power, wherein a resonance frequency of the resonance circuit depending on a temperature of the organ, and wherein, in response to a change in the temperature of the organ, the resonance circuit is configured to change an intensity of the electrical power supplied to the ECD.

2. The device according to claim 1, and comprising a MF source external to the organ and configured to generate the MF, wherein the MF source: (a) comprises an external inductor configured to generate the MF in response to receiving an electrical current, and (b) configured to (i) supply the electrical current to the external inductor, and (ii) sense a change in the supplied electrical current in response to the change in intensity of the electrical power supplied to the ECD.

3. The device according to claim 2, wherein the MF source is configured to supply the electrical current having a given frequency, wherein at a first temperature of the organ the resonance circuit has a first resonance frequency and configured to supply a first power to the ECD, and at a second temperature of the organ the resonance circuit has a second resonance frequency, different from the first resonance frequency, and configured to supply, to the ECD, a second power different from the first power.

4. The device according to claim 3, wherein the resonance circuit comprises a capacitor and an inductor interconnected in parallel to one another, and wherein at least one of (a) a capacitance of the capacitor, and (b) an inductance of the inductor is configured to change in response to altering temperature of the organ.

5. The device according to claim 4, wherein, in response to the altering temperature of the organ, the capacitor is configured to change the capacitance by changing a distance between conductors of the capacitor.

6. The device according to claim 5, wherein the capacitor comprises a microelectromechanical (MEMS) device.

7. The device according to claim 4, wherein the inductor has a ferrite component configured to increase the induction of the inductor, wherein a permeability of the ferritecomponent depends on the temperature, and wherein based on the ferrite component, the inductor is configured to change the inductance in response to the altering temperature of the organ.

8. The device according to claim 1, and comprising a subdermal MF source implanted between a scalp and the organ and configured to generate the MF, wherein the MF source: comprises (i) an additional inductor configured to generate the MF in response to receiving an electrical current, and (ii) a power storage apparatus configured to supply the electrical current to the external inductor.

9. The device according to claim 1, wherein the ECD comprises one or more light emitting diodes (LEDs), which are coated with a biocompatible material configured to electrically isolate between the one or more LEDs and tissue surrounding the one or more LEDs, and wherein the one or more LEDs are configured to apply to the brain light in response to receiving the electrical power.

10. The device according to claim 9, wherein at least one of the LEDs is configured to produce a temperature signal indicative of the temperature of the organ.

11. The device according to any of claims 2-10, and comprising a processor that, in response to the sensed change in the supplied electrical current, is configured to produce a control signal indicative of the temperature of the organ.

12. The device according to claim 11, wherein the processor is configured to control the temperature of the organ in a closed loop based on one or more signals indicative of the temperature of the organ.

13. The device according to any of claims 2-10, wherein the organ comprises a head of a patient, and wherein the device is configured to be implanted in the head (i) between a scalp and a skull, or (ii) between the skull and a dura, for performing an optogenetic activation in a brain of the patient.

14. The device according to any of claims 2-10, wherein the resonance circuit comprises (a) a stent, which is shaped to be implemented in a blood vessel, and is configured to (i) receive the MF, and (ii) convert the MF to the electrical power, and (b) electrical leads for connecting between the stent and at least the ECD.

15. The device according to claim 14, wherein the stent comprises an alloy of nickeltitanium, which is at least partially coated with a biocompatible material configured to electrically isolate between the stent and tissue surrounding the stent.

16. The device according to claim 14, wherein the stent comprises (i) an electrically conductive wire, and (ii) a layer of polyether ether ketone (PEEK), which is coated over the electrically conductive wire and configured to electrically isolate between the electrically conductive wire and tissue surrounding the electrically conductive wire.

17. A method for fabricating a device intended to be implanted in an organ, the method comprising: producing a resonance circuit, for (i) receiving a magnetic field (MF), and (ii) converting the MF to an electrical power, wherein a resonance frequency of the resonance circuit depends on a temperature of the organ; and integrating the resonance circuit with an energy consuming device (ECD) configured to receive the electrical power and to apply energy to the organ, wherein in response to a change in the temperature of the organ, the resonance circuit changes an intensity of the electrical power supplied to the ECD.

18. The method according to claim 17, wherein producing the resonance circuit comprises (i) producing at least a capacitor and an inductor, wherein at least one of (a) a capacitance of the capacitor, and (b) an inductance of the inductor, changes in response to altering temperature of the organ, and (ii) interconnecting the capacitor and the inductor in parallel to one another.

19. The method according to claim 18, wherein producing the inductor comprises producing a stent having an electrically conducting coil coated with an electrically insulating layer.

20. The method according to claim 19, wherein the electrically conducting coil comprises an alloy of nickel and titanium.

21. The method according to claim 19, wherein the electrically insulating layer comprises poly ether ether ketone (PEEK).

22. The method according to claim 18, wherein producing the capacitor comprises (i) connecting the ECD to an electrically conducting lead, (ii) positioning first and second edges of the electrically conducting lead at a predefined gap from one another, and (iii) disposing a dielectric layer in the gap between the first and second edges.

23. A method, comprising:in a device implanted in an organ and having: (i) an energy consuming device (ECD) for applying energy to the organ in response to receiving electrical power, and (ii) a resonance circuit whose resonance frequency depends on a temperature of the organ, receiving a magnetic field (MF) from a MF source external to the organ; converting the MF to the electrical power; and in response to a change in the temperature of the organ, changing an intensity of the electrical power supplied to the ECD.

24. The method according to claim 23, wherein the MF source comprises an external inductor for generating the MF in response to receiving an electrical current, and wherein receiving the MF comprises sensing a change in the supplied electrical current in response to the change in intensity of the electrical power supplied to the ECD.

25. The method according to claim 24, and comprising in response to receiving a first signal indicative of a change in the supplied electrical current, produce a second signal indicative of the temperature of the organ.

26. The method according to any of claims 23-25, wherein implanting the device in the organ comprises implanting the device in a head of a patient, (i) between a skin and a skull of the head, or (ii) between the skull and a dura of the head, and performing an optogenetic activation in a brain of the patient.

27. The method according to any of claims 23-25, wherein implanting the device comprising implanting: (a) the resonance circuit comprising a stent, which is shaped to be implemented in a blood vessel for receiving the MF and converting the MF to the electrical power, and (b) electrical leads for connecting between the stent and at least the ECD.

28. A subdermal pulse generating device, comprising: an energy consuming device (ECD) configured to receive electrical power and to apply energy to the organ; a power storage apparatus configured to supply the electrical power to the ECD; and an antenna, which is configured to (i) receive a magnetic field (MF), and (ii) convert the MF to the electrical power for at least one of: (a) charging the power storage apparatus, and (b) supplying the electrical power to the ECD.

29. The device according to claim 28, wherein the power storage apparatus comprises one or more rechargeable batteries.

30. The device according to claim 28, wherein the antenna comprises a first inductor, and comprising a MF source external to the organ and configured to generate the MF, wherein the MF source: (i) comprises a second inductor configured to generate the MF in response to receiving an electrical current, and (ii) configured to supply the electrical current to the second inductor.

31. The device according to claim 30, wherein the MF source is implemented in a wearable clothing item.

32. The device according to claim 30, wherein the MF source is implemented in bed linen.

33. The device according to claim 28, and comprising a processor, which is configured to (i) sense a temperature of the organ, and (ii) control the electrical power supplied to the ECD in order to maintain the temperature within a predefined range.

34. The device according to claim 28, wherein the processor is configured to produce a signal indicative of the sensed temperature of the organ, and to display the sensed temperature to a user over a display.

35. The device according to any of claims 28-34, wherein the organ comprises a head, and wherein at least the ECD, the power storage, and the antenna, are implanted between a skull and a scalp of the head.

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