Method and Apparatus for treatment of viral infections
20240001137 ยท 2024-01-04
Inventors
Cpc classification
International classification
Abstract
The Method for the treatment of patients with viral infections such as COV-2-BARS or others using Microwave Resonant Absorption (MRA) effect in viruses and based on Structure Resonant Energy Transfer (SRET) that causes Confined Acoustic Vibrations (CAV) in infectious viruses and, as a result, their destruction. Devices using coupling of multi-frequency microwave energy to the patient organs infected with virus with Near Field Focused (NFF) antenna arrays, implemented to irradiate infected organs such as lungs, larynx, and nasofarinx by exciting high amplitude acoustic vibrations to fracture the outer protein shell (capsid) of the virus and completely or, at least, partially inactivate it.
Claims
1. A method of treatment a patient infected with a virus comprising: a) identifying the virus which infected the patient; b) determining an acoustic resonant frequency or frequency bandwidth corresponding to the identified virus; c) identifying a threshold field strength E.sub.th and a power density P.sub.th required for a complete or a partial destruction of the virus in a patient's organ designated for a treatment; d) mapping the patient's organ designated for the treatment using MRI, tomography or another imaging method and using results for programming an antenna array beam forming network (BFN); e) developing a model for the organ designated for the treatment of an EM wave propagation through anatomical tissue layers using numerical bioelectromagnetics; f) selecting a Near Field Focus broadband antenna array which is best applicable for irradiation of the patient's organ designated for the treatment and having an operating bandwidth wide enough to operate at a single resonant frequency, or simultaneously operate at several separate frequencies, or operating in a continuous frequency sweeping mode over specific frequency band corresponding to a CAV frequency range of the virus, using in a Near Field Focus technology at least one microstrip array, horn antennas, linear dipoles and monopoles, spiral antennas, waveguide apertures, Vivaldi arrays, waveguide slot arrays, and other antennas suitable for the treatment of the patient's organ; g) creating a space/time plan of movement of a focal spot for treatment of the infected organ based on information obtained during mapping of the patient's organ in 1d); h) creating a software program for phase/amplitude values according to plan 1g) for steering a focal spot of a selected Near Field Focus antenna array over a full volume or a partial volume of the organ designated for the treatment, and controlling the steering by a digital Beam Forming Network; i) connecting a microwave source or microwave sources operating at a single frequency, or several frequencies, or continuously sweeping over the identified in 1b) frequency band width and having a sufficient power delivered to radiating elements to achieve the identified threshold field strength and the power density determine in 1c) in the focal spot required for a complete or a partial destruction of the identified virus in the patient's organ designated for treatment; j) controlling a temperature of the organ designated for treatment to prevent overheating of surrounding tissues using a microwave radiometer connected to the same irradiating Near Field Focus antenna array antenna or to a separate Near Field Focus antenna array; k) if two different antenna arrays or different frequencies are used for temperature control, setting phase parameters of both receive and transmit antenna arrays in such a way that focal spots from the both arrays provide a synchronous 3-D movement inside of the organ under the treatment covering the same area inside of the organ designated for the treatment, and so that when a common Near Field Focus antenna array is used for irradiation (transmit, Tx) functions and for a temperature control (receive, Rx) functions, a condition of a synchronous movement of Tx and Rx focal spot will be satisfied automatically if the same frequency or frequency band is used for Tx and Rx operation; and conducting approximately 15 minutes to one hour treatment sessions to eradicate the virus.
2. The method according to claim 1a), further comprising using the method for the treatment of a patient infected with the virus selected from the group consisting of an influenza A virus, an enterovirus EV71, a pleiomorphic Coronavirus SARS-Cov-2, and other viruses with acoustic resonant frequency in a microwave band 3 GHz-100 GHz.
3. The method according to claim 1f), and further comprising using different microwave antenna arrays for targeting different organs which require the treatment, selected from the group consisting of but not limited to lungs, larynx, or nasal cavities.
4. The method according to claim 1f), and further comprising transmitting by the selected antenna arrays radiating electromagnetic waves with a linear polarization or a circular polarization, depending on a type and a shape of the virus.
5. The method according to claim 1, further comprising connecting the microwave antenna arrays to a microwave power source with operating parameters identified in claim 1i.
6. The method according to claim 1j, further comprising using as temperature monitoring means a microwave radiometer receiver with an operating frequency at which the organ designated for treatment has a significant absorption using a Plank's Law of Black Body Radiation or working in the same frequency band as irradiating system; and connecting the radiometer-receiver to the antenna phase array creating a Near Field Focus pattern focused and steered at the same area of the organ as the treatment antenna array in claim 1f) and is used for measuring temperature at tissue layers around treatment spot in order to control irradiating power not to exceed safety level.
7. The method according to claim 6, and further comprising of a synchronized movement of focal spots of the radiometer antenna array and the treatment antenna array in location and time if a separate antenna is used for the radiometer, or satisfying this requirement by using a common or the same antenna array for irradiation and radiometer functions and with a radiometer operating frequency band falling within a Tx frequency band.
8. The method according to claim 1, and further comprising of a selected microwave source frequency at Microwave Resonant Absorption (MRA) frequency band causing a maximum Structure Resonant Energy Transfer (SRET) that results in a high amplitude of CAV in the infecting virus and, ultimately, in its destruction.
9. The method according to claim 1; and further comprising using a detailed 3-D structural picture created by MRI, X-Ray or other methods to properly model an EM wave propagating media using a Finite Difference Time Domain (FDTD) method for planned in 1g) positions of the focal spot for treatment of the infected organ and a program phase array controller in the Beam Forming Network for focal spot time and space movement inside of a large organ, or for a correct position of a focus of the antenna arrays on smaller organs that can use a stationary focal point.
10. The method according to claim 1, further comprising using microwave radiators for treatment of internal organs located inside of a patient body and which are formed as antenna arrays designed in such a way that the highest electric field strength is created in a volume occupied by an organ designated for treatment while radiating elements are located in the proximity of the organ.
11. The method in claim 1d), wherein the EM model created in claim 9 is used for calculating variable phase and amplitude weight coefficients in the Beam Forming Network for microwave radiators of array used for treatment of organs, allowing a focal spot with a high power density to move inside the organ designated for treatment providing essentially 3-dimentional treatment capabilities.
12. The method according to claim 3, further comprising using for the treatment of different organs that are not located deep in the patient's body such as for example larynges or nasal cavities, but closer to a surface, conformal microwave radiators of suitable shapes with or without Near Field Focus.
13. The method according to claim 1f), further comprising positioning antenna array outside of the body and placing it in a close proximity of the organ designated for treatment, so that if lungs are under the treatment, the antenna array is positioned across a chest and/or a back, and/or sides of a patient torso, and if larynges are under the treatment the antenna array is positioned around a neck of a patient, if nasal cavities are under the treatment the antenna array is positioned near a face of the patient.
14. The method according to claims 1 and 4, further comprising using an electromagnetic power source or sources which can produce several fixed frequencies or a frequency sweeping around a central frequency equal to a frequency of the MRA, with bandwidth of up to +/35% to affect virions that have different sizes and mass.
15. The method according to claim 1, further comprising using irradiating arrays having a fixed phase shift between radiating elements that will cause a movement of the focal spot of the antenna array in a vicinity of the infected organ to cover different parts of it, when an electromagnetic power source produces a variable frequency sweeping around a central frequency.
16. An apparatus for microwave radiation treatment, comprising: a) a microwave power generator or several generators having operating frequency equal or close to microwave frequency at which maximum SRET power has been absorbed by specified in 1b) viral pathogen, or capable of radiating variable frequency, or several fixed frequencies covering bandwidth of MRA for viruses with different sizes and mass; b) the power of the generator(s) must be equal or above the level sufficient to provide the field strength and power density at the organ under treatment to produce Confined Acoustic Vibrations (CAV) with amplitude above the threshold to cause acousto-mechanical destruction of the virus shell (capsid lyses); c) the conformal antenna array corresponding to method in claim 9, wherein it has a gain capable of creating focal spot to irradiate organ under the treatment with said NFF spot having electrical field strength and power density sufficient to cause CAV in the virus with amplitude producing a destructive stress in the virus lipoid capsid; d) conformal antenna array where digital beam-forming is implemented for computerized control of amplitude and phase of radiating elements to create the focused microwave energy spot in the required positions inside of the organ under the treatment using data obtained in claim 1d as a guidance. e) the conformal arrays of claims 12 and 13, wherein the radiating elements that are used for treatment of the organs located deep inside of the body (lungs, for example) and may use high EM power, are thermally insulated from the skin by layer of dielectric (so called coupling bolus) with circulating liquid to minimize rise of the skin temperature caused by high EM power application and protecting nearest fat and muscle tissues; also using said bolus to provide impedance matching to minimize surface reflections from the antennabody interface by selecting circulating liquid with proper dielectric constant and low microwave loss coefficient (low tan); f) the conformal arrays of claim 17e that are used for different organs treatment and require cooling bolus, wherein said arrays are printed on flexible printed circuit board (PC-board) and located inside of the conforming water bolus, wherein antenna array PC-boards and cooling bolus are assembled into elastic support structure in the shape of the vest that snugly fits the patient torso or in the shape of the collar to fit around patient's throat, or in the shape of nose maxilla to irradiate nasal air passage and sinuses area; g) vest in claim 17f wherein, if the separate irradiating array and radiometer array are selected, they are placed on the opposite sides of the vest, for example: if the irradiating antenna PC-boards are located in part of the vest covering the front of the torso, the radiometer antennas will be located at the rear (posterior) part of the vest, or at the torso lateral sides; h) the conformal array of claim 3 in the shape of collar with or without bolus around the neck of the patient with the goal of irradiating virus infected larynges located in this area; i) array assembly of claim 16h, wherein depend on the results of claim 1d) the water bolus may or may not be used for treatment procedure; j) the antenna array assembly of claim 3 in the shape of two NFF arrays with two planar or curved PC-boards assembled as a two-panel assembly with the angle between two planes and the size of the planes is determined by the anatomy of the patient, said assembly positioned in the patient face proximity.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
[0093] COVID-2-SARS infecting process takes approximately 10 hours during which the virus makes intracellular virions [15]. This source also reports the amount of viruses per swab from nasal-pharynges area as up to 10.sup.9 RNAs/swab and from throat phlegm up to 10.sup.11 RNAs/ml. It is obvious, that even partial weakening of viral load in the body by microwave radiation using SAR for virus destruction will decrease the severity of the disease.
[0094] The invention discloses the method and apparatus for noninvasive treatment of patients, who contracted viral infections such as COVID-19, influenza, and other viral diseases, using phenomenon of microwave energy coupling to acoustic energy vibrations inside of the virus capsid, leading to its' lyses and destruction.
[0095] The discovery of the possibility of coupling of acoustic resonant vibrations in viruses to the external electromagnetic waves in [3], [4], [5], [6] with frequency equal to virion's acoustic resonance frequency created a possibility of swinging the charges in by-polar shell of the virus with electric field amplitude high enough to cause the rupture of virion protein capsid. The SAR method require certain threshold electrical field amplitude. To achieve this goal, the direct application of the microwave energy from external source through antenna, as described in [4] will require prohibitively high power density at the skin surface.
[0096] The present application deals with a method using NFF antenna arrays for external delivery of lowest possible EM field by creation of small spot of concentrated energy inside of the organ containing viruses with required power density to destroy the virus. The focal spot is moved inside of the organ in a controlled way to irradiate full volume of the organ. For COVID-19 and other SARS viruses treatment it can be lungs or larynges, or nasal passages. The safety of the patient is ensured by monitoring of the tissue temperature in the vicinity of the irradiated spot by passive microwave radiometer connected to the irradiating array or separate NFF antenna array operating at lower frequency for better body penetration in which focal spot movement is synchronized with movement of the irradiating spot. Another advantage of the proposed method is that it teaches practical implementation of the simultaneous application of multiple frequencies or broad band frequency continuous sweeping for destruction of Covid-19 viruses with range of different sizes and/or mass originally suggested in [6].
[0097] The present application exploits extreme flexibility of NFF antenna arrays to control the side-lobe level, shape the 3 dB focal spot, implement multifocus patterns, and electronically stir the focal point in 3-D space.
[0098] The proposed treatment procedure for the NFF antenna array used for SARS virus infected patient is as follows: [0099] 1. After clarifying the type of the virus that infected the patient, determine the exact dimensions of the patient's organ under the treatment using X-ray or MRI or other methods. Use measured parameters of the organ in the program for control of the movement of irradiating focal spot. [0100] 2. Estimate electrical field amplitude and microwave power density required for virions rapture. If this is the case of COVID-19 infection, the reported value of P.sub.th=14 W/m.sup.2 is acceptable value for 100% eradication over 15 minutes session. P.sub.th=1.5 W/m.sup.2 allowed for 38% of virus deactivation [3], [4], [6]. [0101] 3. Select the frequency of the microwave source equal to acoustic resonant frequency of the virus. For SARS-CoV-2 viral infection typical frequency band is 8.5-17 GHz [4], [6]. [0102] 4. Estimate propagation losses from the skin surface to the center of the organ. Create theoretical model of multilayer EM wave propagation from NFF antenna array positioned outside of the body through layers of skin, fat, muscle, and others to the organ to be irradiated. For this task multidisciplinary optimization software (MDO) such as VSimEM, XFdtd, and others can be used. The detailed description of the method using Finite Difference Time Domain (FDTD) is given in [23]. [0103] 5. Select microwave matching of propagation medias between antenna array and human body to minimize reflections (this matching layer called bolus). Using circulating liquid dielectric, the bolus is also can be used for cooling of the nearest layers of the skin and fat from temperature rise caused by irradiating array. The results of multiple experiments and studies of the dielectric constant of this matching layer shows that the minimum reflections were achieved by the layer having thickness close to of the operating wavelength and dielectric constant in the range of 5 to 10, depending on the irradiated area of the body. In some applications, such as nasal cavities or larynges, the bolus may not be needed. [0104] 6. Select the appropriate microstrip conformal NFF array(s) with focal points capable to irradiate the entire organ. Preprogram the beam-former processor for 3-D focal spot movement using size/location information of the organ obtained in the steps 1 and 4. [0105] 7. Similarly to step 6, select location and parameters of the passive temperature monitoring array and synchronize the movement of focal spot of the radiometer array with movement of the irradiating focal spot.
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[0108] This temperature monitoring method implies lower frequency NFF phased array located on the opposite side of the body in reference to the irradiating array and having synchronized movement of the focal spot in such a way that spots of both arrays cover the same volume with the temperature array receiving spot located where the maximum EM energy absorption happens, usually in the area with the maximum microwave propagation loss. Arrays 54 shown in
[0109] Radiometer conformal receiving arrays can be positioned on the opposite side of the patient's body to avoid obstruction for irradiating arrays. Two separate antenna arrays for temperature monitoring are shown in
[0110]
[0111] A block diagram of the first embodiment of the method described above with TX and Rx separate arrays is shown in
[0112] This embodiment allows for a maximum flexibility because the position of the receive and transmit arrays' focal spots can be independently controlled. As can be seen from the diagram in
[0113] The second embodiment of the method of the invention with a temperature control and monitoring is shown in
[0114] The third embodiment of the system is shown in
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[0118] An apparatus of the invention for a lungs treatment will be now described in detail. The lungs occupy most of the volume inside of the rib cage (thorax) and, in case of the SARS infection, can be a major source of the new virion creation accompanied with rapidly worsening patient condition. It has to be noticed that the goal of this treatment is not a thermal ablation in the irradiated organ, like it is done in a hyperthermia tumor treatment, but a delivery of a lower power microwave radiation for virus destruction in the organ. Therefore, many other technical solutions may be implemented that can produce controlled focused microwave radiation at different parts of the infected organ.
[0119] In
[0120] In order to irradiate lungs with microwave energy with a level high enough to destroy SARS virions, the patient is subjected to the focused microwave beam which intensifies the energy density at the focal spot 100 times (20 dB) compared to non-directional source [14]. The focal spot or multiple spots has to be moved in 3D direction covering most of the lung volume in order to be effective in virus destruction. Irradiation from one side (back or posterior side, for example) of the lung will require the maximum focal distance from the surface of the rib cage approximately 3.5 cm or of the lung depth. After completing the treatment from the posterior side, the treatment from the front (anterior) side can be provided and positions of Tx and Rx arrays (if used) can be switched (
[0121] Following the plan described above and listed in
TABLE-US-00002 TABLE 2 Required Required SARS Power Power Acoustic Density for Density for Resonance Complete 38% Frequency, Eradication, Eradication, Virion GHz [3] W/m.sup.2 [6] W/m.sup.2 [3] CoV-2- 6.5-9.5-10.5 14.5 1.5 SARS
[0122] There is a wide range of frequencies that can cause Structure Acoustic destruction of CoV-2-SARS virus (8.5 GHz-17 GHz, [6]). In [6] also was suggested to sweep irradiating frequency to cause the faster lyses of capsid of viruses with different sizes and mass, and, therefore, different Acoustic Resonance frequencies. In the present invention four separate frequencies or swiping over the smaller frequency band located at the lower end of the range are suggested (Table 2). The reason for that is the variation of the frequency band +/20% will cause insignificant changes in the position and size of the focal spot, which simplifies the control algorithm. It is important to note, that during the frequency sensitivity study in [3], authors observed shallow resonance in the inactivation ratio over the bandwidth of 35% with the inactivation ratio of virions more than 80% with more pronounced effect at the lower side of the resonance curve. Operating at the lower part of the Acoustic Resonance Frequency band (Table 2) will require less radiating power because of the smaller losses in a human tissue at lower frequencies. Using data obtained in the second step, the treatment plan and positions of the focal spot for 3-D exposure of the patient's organ under the treatment has been recorded and the limiting borders of lungs irradiation have been determined.
[0123] Losses in human body depend on electrical properties of the layers of human tissue through which the desired microwave energy has to pass under treatment by a microwave irradiation. Some EM parameters of human tissue layers under consideration is shown in
[0124] In
[0125] The EM wave propagation studies through human tissues show that X and Ku bands microwave frequencies will experience very high losses. The International Commission on Non-Ionizing Radiation Protection (ICNIRP) stipulated the safe microwave power density within 200 W/m.sup.2. In order to limit an input microwave power to which the skin surface will be exposed below 200 w/m.sup.2, the maximum value of loss at selected frequencies has to be properly calculated for the organ under the treatment. In order to overcome significant losses experienced by EM beam propagating through different layers to reach the organ with required power density, the applied power density at the surface of the skin must be significantly higher than the safety limit. In order to overcome this problem and protect the patient from overheating by microwave energy the device called bolus has been developed and used for a cancer patient treatment [41]. Using a local cooling effect created by the bolus the order of magnitude higher power density can be applied [39]. In [45] the method of treatment of neck tumors using the bolus for cooling of the surface tissues has been described. The applied power was reaching 1000 W in that study.
[0126] Table 3 demonstrates the effect of high dielectric constant of human lungs on the wavelength and focal spot diameter at selected operating frequencies. As was mentioned in [6], to destroy viruses with different size and mass, the most prudent way to fight COVID infection will be a simultaneous radiation at several microwave frequencies. In this embodiment frequencies have been selected based on results of investigation in [3], where it was shown that inactivation efficiency did not deteriorate significantly up to the lowest frequency 6.5 GHz. At this frequency more than 70% of the virus was inactivated after 15 minutes exposure. The highest operating frequency of the embodiment was selected based on a reasonable penetration of the microwave beam into the lungs volume and implementing a cooling bolus to protect the outermost tissues. Using a deionized water a cooling bolus tightly applied to the body surface, and assuming power density at the focal spot has to be 3 times or more above the virus destruction threshold power, the maximum propagation loss can be calculated. Calculations for the bolus operating parameters are provided in with the recommended water temperature of 30 C for deeper EM energy tissue penetrations. The desired range of exterior skin temperature must be kept in 40-42 C. or below pain threshold. The total power was selected from experimental results to obtain maximum temperature of 40 C. in healthy tissues using a typical bolus for cooling and matching. The bolus assembly containing the conformal microstrip arrays for this apparatus embodiment is shown in
[0127] For convenience of the tight enveloping around the torso for lungs treatment the bolus 131 has a shape of a vest made of materials available in the industry and used for the bolus manufacturing elsewhere [39]. In
[0128] Four frequencies that fall in the COVID-19 virion SAR band have been selected for this embodiment. It can be reasonably assumed that the array applied power for each frequency will be 100 W. Results calculated on the premise that for a typical short focused NFF antenna array the focal spot has a diameter of 1 .sub.g are shown in Table 3. Several single frequency oscillators can be substituted by a single slow sweeping or stepping oscillator capable of operating in SAR frequency range.
TABLE-US-00003 TABLE 3 Frequency, GHz 6.5 8.5 9.5 10.5 .sub.r lungs 18 17 16.4 15.90 g in lung, cm 1.09 0.86 0.78 0.72 d spot, g 1 1 1 1 Power Density Required, w/m2 5 5 5 5 Power of the external source, w 100 100 100 100 Allowed Propagation Loss, dB 73.33 75.41 76.22 76.96
[0129] In Table 3 Allowed Propagation Loss was calculated as a ratio between a required power density at the focal spot for virus destruction and an applied safe power density using bolus. One can notice that the actual focal spot diameter is approximately the same for all frequencies because of the frequency dependence of lungs' relative dielectric constant .sub.r. This phenomenon simplifies a control of a focal spot for a broad band frequency operation.
[0130] The third step requires a creation of a space-time control movement of the focal spot of the array. For general requirements for the array parameters, the specific to the organ propagation path and losses should be analyzed. For the lungs treatment the detailed propagation analysis through the human body has been done in [22]. The charts published in this work can be used for different operating frequencies applied for the treatment.
[0131] By interpolating these charts for selected operating frequencies for this apparatus embodiment, Table 4 with information for a lungs penetration depth for each frequency has been calculated.
[0132] Using charts published in for calculation the EM wave propagation losses for different tissue layers the penetration depth of the focal spot with power density of 5 W/m.sup.2, which is more than three times of the minimum threshold power density 1.5 W/m.sup.2, can be found from Table 4.
TABLE-US-00004 TABLE 4 Frequency, GHz 6.5 7.5 8.5 9.5 Thicknss, Loss, Loss in Loss, Loss in Loss, Loss in Loss, Loss in Tissue cm dB/cm Tissue, dB dB/cm Tissue, dB dB/cm Tissue, dB dB/cm Tissue, dB Skin 0.3 3 1 5 2 6 1.8 7 2.1 Fat 0.2 3 0.6 5 1 6 1.2 7 1.4 Muscle 1.5 10 15 13 19.5 15 22.5 17 25.5 Cartilage 0.6 13 8 17 10.2 19 11.4 23 13.8 Lungs 12 16 20 23 Propagation Loss to 24 33 37 43 Lungs Allowed loss in Lungs 49 42 39 33 Maximum Lung 4.1 2.6 1.9 1.5 EM Energy Penetration, cm
[0133] The calculations in Table 4 have been made for the applied power at array of 100 W per carrier. The penetration depth values are typical and must be calculated for each individual patient considering anatomy of his organ, size of array, and used frequencies for treatment. Table 4 demonstrates that using the microstrip NFF antenna array with practically realizable power at the source, the multi-frequency irradiation method of COVID-19 lungs treatment is possible with a significant penetration of a microwave energy into the lungs volume with a sufficient power density level to cause Confined Acoustic Vibrations (CAV) in infectious viruses and, as a result, their destruction. As it follows from safety irradiating power limitations, with properly designed bolus the simultaneous irradiation of lungs with several frequencies from anterior and posterior positions of NFF arrays can achieve a full lungs volume treatment using the proposed embodiment.
[0134] It is important to note that EM energy penetration in lungs significantly depends on the patient's anatomy and in some cases the losses in tissues may be very high, prohibiting irradiation of lungs at higher frequencies because of the safe power limitations for the specific bolus design. In this case a longer time irradiation at lower frequencies may be implemented to achieve a desirable result and keep the power density at the irradiation spot above P.sub.th.
[0135] In the next step of this embodiment design the actual antenna array approach is selected. As it was discussed earlier, a conformal printed circuit array is the most suitable antenna solution. Conformal printed circuit arrays with a near field focus allow significant 3-dimentional freedom in positioning of the focal spot at the desirable location simply by changing the phase relationship between radiating elements. It can be seen from equation (4) that describes a phase conjugate approach to create a focal point where radiating fields from all elements will be added in-phase:
.sub.mn=2/*R.sub.focalR.sub.mn2,(4)
wherein [0136] .sub.mn is the relative phase between the radiating elements, [0137] is the free-space wavelength, and [0138] .Math..sub.2 stands for the Euclidean distance.
[0139] From (4) it can be seen that by changing the phase shift between the elements of the array, the position of the focal spot can be changed in a three-dimensional space. There are multiple sources discussing different methods of NFF antenna array design including an advanced computer based electromagnetic field modeling [14], [15],[16]. The method described below serves as an example of possible practical solution for this embodiment implementation.
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[0141] To avoid a beam squint effect for wide band applications, which exists for narrow band transmission line phase shifters, the time delay solution is used for this embodiment for the control of the phase in DBF. The ability of DBF to compensate for a phase and time delay of different array elements allows significant independence of the antenna geometry from desired performance, making many different configurations feasible, including a practically frequency independent convenient physical shape conformal array. Contemporary ASIC modules [23] contain all necessary digital circuitry including A/D and D/A converters that needed for a computer controlled beam synthesis.
[0142] In order to fully realize the benefits of a multi-frequency organ irradiation, the elementary radiating elements must be broadband with low VSWR over the operating band. There are several classes of antennas operating over octave or even wider bandwidth. In this embodiment a bow-tie radiator type is selected because of its planar geometry and easy adaptability for a microstrip design [27]. In
[0143] In
[0144] By connecting these outputs to two eight-way power dividers 164 one can create a broadband input network for sixteen sub-arrays. Two big dotted line module groups indicate the equipment assembled in an external control rack marked EXTERNAL CONTROL RACK, which is connected to the patient module marked PATIENT VEST with a water bolus and microwave NFF antenna arrays via cable assemblies.
[0145] For this embodiment parameters of the focused beams of an 88 NFF array of 6.5 GHz-10.5 GHz broad band butterfly patches are shown in Table 5. Outline dimensions of one NFF array is approximately 12 cm12 cm. Four such array assembled into a vest wearing by a patient can provide EM energy for both lungs from the front or from the back sides of the body.
TABLE-US-00005 TABLE 5 Frequency, GHz 6.5 7.5 8.5 9.5 10.50 o, cm 4.6 4.0 3.5 3.2 2.9 g, lungs 2.06 1.79 1.58 1.41 1.28 Elements 0.56 0.64 0.73 0.81 0.90 Space, g D, space sub- 2.30 2.30 2.30 2.30 2.30 array, cm
[0146] A bolus dielectric constant for the parameters shown in the Table 5, is =5. The bolus serves not only for a skin cooling purpose, but also to provide a matching layer between an antenna array and human tissues. As can be expected, because of the broadband properties of the radiating structure, the geometrical parameters of the focal spot will be frequency dependent. A calculated diameter of the focal spot as a function of the focal distance from the array plane is shown in
[0147] Numerical analysis demonstrates that, for a given antenna size, movement of the focal spot in the organ is accompanied with the changing of the diameter of the focal spot (see Table 3). This variations in the treatment area will cause the change in the power density of irradiation and, therefore, may require the adjustment of the input power, which may be different for different frequencies. Moving the array closer to the skin surface will make a focal distance smaller, and, correspondingly, the diameter of the focal spot smaller, up to a minimum .sub.g/3 [42], which also may be considered during the treatment plan stage.
[0148] An apparatus for larynges treatment according to the present invention will now be described.
[0149] Prior to each treatment, similarly to the lungs treatment procedure, the treatment planning (TP) is required to obtain information about the optimal amplitude and phase settings for each channel in the phased array, and the applicator position around the patient's neck. The anatomy of the treatment area for larynges is shown in
[0150] Analysis of anatomy of an adult patient revealed that the applicator should have a square aperture around 50-60 mm with a bolus for better patient contour conformity. Applying two NFF arrays to two sides of the front area of the neck requires a signal to come through the following body layers structure, shown in the Table 6.
TABLE-US-00006 TABLE 6 Mucous Skin Muscle Cartilage Gland Membrane Dielectric 31.80 43.40 26.30 46 43.40 constant @9.5 GHz, Thickness, cm 0.3 0.3 0.6 0.5 0.8
[0151] A cross-section of the larynx shown in
[0152] The inter-element spacing of arrays 202 in
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[0156] A focal spot control is provided using similar method implemented for lungs treatment embodiment and shown in detail in
[0157] The patient can sit in a chair or lay down on a bed with an antenna arrays holding fixture 225 (
[0158] Other type broad band microstrip radiating elements can be used. The array control is realized using individual Base Band Digital controllers marked BEAMFORMER in
[0159] Considering the anatomy of larynx area, in order to reach a rear mucous membrane area, which is typically get affected by COVID-19 virus, the EM waves must propagate through the thin layers of skin and fat, then thicker layer of thyroid cartilage, and a few centimeters of free space. It results in significantly lower tissue losses than in a lungs irradiation setup and opens up a possibility of using a higher irradiating power density as well as a higher frequency.
[0160] Table 7 displays results of approximate calculations for power requirements and a penetration depth for the proposed typical, larynges treatment embodiment with a power density of 14.5 W/m.sup.2, which is ten times above the critical value for COVID-19 virus destruction. As reported in [6], this power density level will provide 100% virus inactivation over 15 minutes session.
TABLE-US-00007 TABLE 7 Frequency, GHz 9.5 10.5 11.5 12.5 Loss, Loss in Loss, Loss in Loss, Loss in Loss, Loss in Tissue dB/cm Tissue, dB dB/cm Tissue, dB dB/cm Tissue, dB dB/cm Tissue, dB Skin 7 2.1 8 2.4 10 9 12 21.6 Fat 7 0.7 8 0.8 16 4.8 18 10.8 Cartilage 25 15 30 18 35 21 40 24 Propagation Loss to 17.8 21.2 34.8 56.4 Mucous Membrane Layer Maximum Mucous 1.55 1.34 0.85 0.3 Membrane EM Energy Penetration, cm
[0161] Data in Table 7 was estimated for an input power from each frequency source for one array equal to 100 W with a water bolus heat transfer equal 300 W/m.sup.2/K. This data demonstrates that with a proper bolus design the input power for lower frequencies 9.5 GHz and 10.5 GHz can be lower than 100 W to guarantee enough penetration into a gland or mucous membrane of 0.5 cm. Correspondingly, with higher bolus heat transfer parameter even higher frequencies can be used in this embodiment for a better efficiency in virus destruction.
[0162] A nasal cavity and nasopharinx area treatment embodiment according to the present invention is described in detail below. The third area that require early treatment for COV-2-SARS viral infection is nasal cavity and nasopharinx area. Anatomy of this part of the body is shown in
[0163]
[0164] NFF antenna arrays 272 are connected to the control rack with the microwave, baseband and digital equipment via microwave cable assemblies 224, containing 8 coaxial cables connected to each radiator (8 radiators in this exemplary embodiment) for individual phase and amplitude control of EM waves and controlled focal spot location movement inside of the nasal cavity and nasofarinx area. Table 8 shows typical values expected for a setup position in
TABLE-US-00008 TABLE 8 Frequency, GHz 9.5 10.5 11.5 12.5 Loss, Loss in Loss, Loss in Loss, Loss in Loss, Loss in Tissue dB/cm Tissue, dB dB/cm Tissue, dB dB/cm Tissue, dB dB/cm Tissue, dB Skin 7 2.1 8 2.4 10 9 12 21.6 Fat 7 0.7 8 0.8 16 4.8 18 10.8 Cartilage 25 15 30 18 35 21 40 24 Propagation Loss to 17.8 21.2 34.8 56.4 Mucous Membrane Layer Maxim Mucous 1.4 1.12 0.66 0.1 Membrane EM Energy Penetration, cm
[0165] Because of the smaller size and, therefore the lower antenna gain the penetration into the mucous membrane for nasofaringes treatment is less, which can be compensated by using a higher power for a higher frequency and bolus adjustment, if needed. The present invention is not limited to the details shown since various modifications and structural changes are possible without departing from the spirit of the invention. What is desired to be protected by Letters Patent is set forth in particular in appended claims.