Microwave power emission radiation structure for rewarming and resuscitating biological tissue

Abstract

The invention discloses a microwave power emission and radiation structure for rewarming and resuscitating biological tissues, comprising a rectangular resonant cavity (10), an antenna sleeve (20) connected to one end surface of the rectangular resonant cavity (10), the antenna sleeve (20) being connected to the inside of the rectangular resonant cavity (10); an antenna core (30) is further arranged in the antenna sleeve (20), the lower end of the antenna core (30) extends a certain length into the rectangular resonant cavity (10), and a wave-transmitting material for fixing is filled between the antenna core (30) and the antenna sleeve (20); the antenna core (30) is used to emit microwaves into the rectangular resonant cavity (10); the wide side length a, the narrow side length b and the long side length l of the space in the rectangular resonant cavity (10) satisfy a predetermined relationship, so that the microwaves realize the TE101 resonant mode. The structure is conducive to uniform heating of biological tissues, and compared with the prior art, the overall structure is simple and easy to manufacture.

Description

Technical Field

[0001] The invention belongs to the technical field of biological tissue rewarming and resuscitation, and in particular relates to a microwave power emitting radiation structure for rewarming and resuscitating biological tissue. Background Art

[0002] At present, the freezing of biological tissues in the world is very mature, and there are good solutions for freezing single cells, multi-cells, biological tissues, biological organs, etc., which realize the cryopreservation of various biological tissues. However, the technology for rewarming and reviving biological tissues preserved at low temperatures is not mature. The current rewarming technologies include 37℃ water bath rewarming, air rewarming, -20℃ ice rewarming, microwave rewarming, laser rewarming, nano rewarming, etc.

[0003] In the existing microwave rewarming technology, the microwave frequency band of 2450MHz is used for rewarming and resuscitation of biological tissues. Its penetration depth is small, and it cannot achieve a good heating and rewarming effect for larger biological tissues. In order to achieve a greater penetration depth, experiments have shown that it is better to use microwaves in the frequency band of 430-440MHz. However, due to the long wavelength, the emission and divergence of microwaves in the frequency band of 430-440MHz are more complicated. There has been no practical solution to what kind of structure to use in resuscitation and rewarming applications to achieve the emission and radiation of microwaves in this frequency band. Summary of the invention

[0004] One of the technical problems to be solved by the present invention is to provide a microwave power emitting radiation structure for rewarming and resuscitating biological tissues, so as to achieve uniform heating of the biological tissues and thereby rewarm and resuscitate them.

[0005] In order to solve the above technical problems, an embodiment of the present application provides a microwave power emitting and radiating structure for rewarming and resuscitating biological tissues, comprising a rectangular resonant cavity (10), an antenna sleeve (20) being vertically connected to one end surface of the rectangular resonant cavity (10), and the antenna sleeve (20) being communicated with the interior of the rectangular resonant cavity (10);

[0006] An antenna core (30) is also coaxially arranged in the antenna sleeve (20), the lower end of the antenna core (30) extends a certain length into the rectangular resonant cavity (10), and a wave-transmitting material for fixation is filled between the antenna core (30) and the antenna sleeve (20);

[0007] in,

[0008] The antenna core (30) is used to be connected to a microwave feed line to emit microwaves into a rectangular resonant cavity (10); the wide side length a, the narrow side length b and the long side length l of the space in the rectangular resonant cavity (10) satisfy the following relationship so that the microwaves realize a TE101 resonant mode:

[0009]

[0010] Optionally, the width side length is greater than or equal to 340.91 mm and less than or equal to 697.67 mm; the length side length is greater than or equal to 196.82 mm and less than or equal to 805.60 mm.

[0011] Optionally, the width side length is 500 mm and the length side length is 480 mm.

[0012] Optionally, the end surface to which the antenna sleeve (20) is connected is the end surface where the wide side and the long side of the rectangular resonant cavity (10) are located.

[0013] Optionally, the antenna sleeve (20) is a cylindrical sleeve with an inner radius of 45 mm and an inner space height of 102 mm; one end of the antenna sleeve (20) is open, and the other end is closed and provided with a central feeder hole (21);

[0014] A connecting hole (11) is provided on the end surface at a distance of 140 mm from the wide side of the inner space of the rectangular resonant cavity (10) and equidistant from the long sides of the inner space on both sides; the open end of the antenna sleeve is cooperatively connected to the connecting hole (11) so that the antenna sleeve (20) is connected to the inside of the rectangular resonant cavity (10).

[0015] Optionally, the open end of the antenna sleeve is connected to the connecting hole (11) through a flange assembly.

[0016] Optionally, the radius of the central feed line hole (21) is 5 mm, and the upper end of the antenna core (30) extends into the central feed line hole (21).

[0017] Optionally, the appearance structure of the antenna core (30) is composed of an upper frustum (31), a transition frustum (32) and a lower cylinder (33) from top to bottom.

[0018] Optionally, the upper base radius of the upper frustum (31) is 0.45 mm, the lower base radius is 0.5 mm, and the height is 6 mm; the upper base radius of the transition frustum (32) is 0.5 mm, the lower base radius is 25 mm, and the height is 60 mm; the bottom radius of the lower cylinder (33) is 25 mm, and the height is 70 mm.

[0019] Optionally, the antenna core (30) is made of brass.

[0020] Compared with the prior art, one or more embodiments of the above scheme may have the following advantages or beneficial effects:

[0021] (1) Different from the prior art in the art that uses multiple water columns and multiple pins to solve the technical route of reflected waves and resonant frequencies, the present invention realizes the microwave TE101 resonance mode through a specific structural design, so that the radiation in the cavity is uniform, which is beneficial to the uniform heating of biological tissues. Compared with the prior art, the overall structure is simple and easy to produce.

[0022] (2) In the field of rewarming and resuscitation of biological tissue technology, the present application proposes a specific structure for realizing microwave emission radiation in the frequency band of 430 to 440 MHz, thereby providing strong support for solving the problem of microwave penetration in biological tissues and the problem of uniformity of heating inside and outside biological tissues.

[0023] Other advantages, objectives, and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the following description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide a further understanding of the technical solution of the present application or the prior art, and constitute a part of the specification. Among them, the accompanying drawings expressing the embodiments of the present application are used together with the embodiments of the present application to explain the technical solution of the present application, but do not constitute a limitation on the technical solution of the present application.

[0025] Figure 1 is a schematic structural diagram of a microwave power radiation structure according to an embodiment of the present invention;

[0026] Figure 2 yes Figure 1 A schematic illustration of the orientation of each side of the space in the rectangular resonant cavity in the embodiment shown;

[0027] Figure 3a is a schematic structural diagram of an antenna sleeve according to an embodiment of the present invention;

[0028] Figure 3b is a structural schematic diagram of an antenna sleeve from another perspective according to an embodiment of the present invention;

[0029] Figure 4 4 is a structural front view of an antenna core according to an embodiment of the present invention.

[0030] In the figure, 10 is a rectangular resonant cavity; 11 is a connecting hole; 20 is an antenna sleeve; 21 is a central feed hole; 30 is an antenna core; 31 is an upper frustum; 32 is a transition frustum; and 33 is a lower cylinder. DETAILED DESCRIPTION

[0031] The following will describe the implementation methods of the present invention in detail with reference to the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve corresponding technical effects can be fully understood and implemented accordingly. The embodiments of the present application and the various features in the embodiments can be combined with each other without conflict, and the technical solutions formed are all within the protection scope of the present invention.

[0032] In the existing microwave reheating technology, the microwave frequency is 2450MHz, and the single-mode microwave of TE103 mode is used. The standard rectangular waveguide parameters are generally used. The waveguide model is domestic BJ22 (international R22) with a wide side a=109.2mm and a narrow side b=54.6mm, or the waveguide model is domestic BJ26 (international R26) with a wide side a=86.4mm and a narrow side b=43.2mm. The microwave transmitter head uses the transmitting antenna of the microwave magnetron. The rectangular waveguide requires multiple water columns and multiple pins to absorb the reflected waves and adjust the microwave frequency. The penetration depth of 2450MHz microwaves is small, and uniform heating effect cannot be obtained for larger biological tissues.

[0033] In order to achieve a greater penetration depth, experiments show that the 430-440MHz microwave frequency band is better. Microwaves, as electromagnetic waves, have the dual nature of waves and particles, and will self-cancel or self-superimpose to produce standing waves. Microwaves in the frequency range of 430-440MHz have a longer wavelength and belong to decimeter waves. For waves of this level, its transmitting antenna and resonant cavity are more difficult to design, and the combination between them is even more difficult.

[0034] In order to achieve rapid and uniform rewarming of biological tissues, the microwave radiation in the resonant cavity should be relatively uniform. The TE101 mode can achieve uniform microwave radiation in the cavity, and its single-mode operating frequency range is wide and the attenuation is small.

[0035] Therefore, in order to realize the power emission of microwaves and the TE101 mode of uniform microwave radiation, the present invention proposes the following microwave power emission and radiation structure for rewarming and resuscitating biological tissues:

[0036] like Figure 1 As shown, the microwave power emitting and radiating structure in this embodiment includes a rectangular resonant cavity 10, an antenna sleeve 20 is vertically connected to one end surface of the rectangular resonant cavity 10, and the antenna sleeve 20 is connected to the inside of the rectangular resonant cavity 10;

[0037] An antenna core 30 is also coaxially arranged in the antenna sleeve 20, and the lower end of the antenna core 30 extends a certain length into the rectangular resonant cavity 10, and a wave-transmitting material (not shown in the figure) for fixing is filled between the antenna core 30 and the antenna sleeve 20;

[0038] In the microwave power transmitting and radiating structure, the antenna core 30 is used to connect to the microwave feed line to transmit the high-frequency microwave into the rectangular resonant cavity 10; Figure 1 and Figure 2 As shown, the width a, narrow side b and length l of the space in the rectangular resonant cavity 10 satisfy the following relationship (1), so that the microwave realizes the TE101 resonance mode,

[0039] And a=2b (1)

[0040] Different from the prior art in this field that uses multiple water columns and multiple pins to solve the technical route of reflected waves and resonant frequencies, the present invention realizes the microwave TE101 resonance mode through a specific structural design, so that the radiation in the cavity is uniform, which is beneficial to the uniform heating of biological tissues. Compared with the prior art, the overall structure is simple and easy to produce.

[0041] In order to facilitate further understanding of the present invention, the derivation of the internal space dimension relationship equation (1) of the rectangular resonant cavity is briefly introduced below.

[0042] (I) Derivation of the width length a of the space inside the rectangular waveguide resonant cavity (rectangular resonant cavity)

[0043] The distribution of electric and magnetic fields in the rectangular waveguide resonant cavity corresponds to that of the rectangular waveguide, and there are TE-type oscillation modes and TH-type oscillation modes. For the TE mode, Ez = 0 (Ez represents the electric field intensity in the z-axis direction, and Ez = 0 means that the electric field has no component in the z-axis direction). According to the existing results of the rectangular waveguide, based on Maxwell's equations, Hz (Hz represents the magnetic field intensity in the z-axis direction) can be regarded as a standing wave synthesized by the traveling waves transmitted in the positive and negative directions on the transmission line. The Hz components of the TE waves transmitted in the +Z and -Z directions in the rectangular waveguide are superimposed, and the expression (2) of Hz is obtained as follows:

[0044]

[0045] There are boundary conditions at the broadside of the waveguide:

[0046]

[0047] Then we can get the coefficients in the Hz expression as:

[0048]

[0049] When the total phase shift of the electromagnetic wave in the resonant cavity is an integer multiple of π, resonance can occur. Taking the medium filled in the rectangular cavity as air as an example, the boundary conditions (3) of the rectangular waveguide resonant cavity and expression (4) can be obtained:

[0050]

[0051] Where λc is the cutoff wavelength of the rectangular waveguide, and its expression is:

[0052]

[0053] Combining expressions (5) and (6), we can get the relationship between the resonant wavelength and the cavity size in a rectangular resonant cavity:

[0054]

[0055] For a rectangular resonant cavity of a certain size (a, b and l are constant), different resonant modes (different combinations of m, n, and q) correspond to different resonant frequencies and resonant wavelengths, that is, they correspond to different distributions of electric and magnetic fields under TEmnq resonant fields or THmnq resonant fields. The lowest mode in a rectangular waveguide is the TE10 mode, and its cutoff wavelength is the longest λc=2a. Therefore, it is possible to achieve single-mode transmission in the waveguide. The TE10 mode is also called the main wave in a rectangular waveguide and is the most important wave type in a rectangular waveguide. In practical applications, rectangular waveguides all work in the TE10 mode. TE10 refers to electromagnetic waves in a standard rectangular waveguide with a magnetic field component but no electric field component along the propagation direction. The "1" in TE10 refers to a half-wave change in the electromagnetic field in the direction of the wide side of the rectangular waveguide, and the "0" refers to a uniform distribution on the narrow side. The longitudinal single full standing wave mode formed by the TE10 mode is the fundamental mode of the rectangular resonant cavity or the TE101 mode.

[0056] Only single-mode TE10 mode can be transmitted in a rectangular waveguide, so the main mode resonating in the rectangular resonant cavity is also one of the TE10q modes. In order to achieve single-mode resonance, the corresponding rectangular waveguide must be designed as a single-mode waveguide. The conditions for single-mode transmission of the TE10 main mode are:

[0057]

[0058] (II) Derivation of the side length l of the space inside the rectangular waveguide resonant cavity

[0059] Using expression (7), the resonance condition of the TE10q series mode in the rectangular resonant cavity is:

[0060]

[0061] Combining expressions (8) and (9), we can get:

[0062]

[0063] According to expression (10), the condition for the TE10q resonance mode to resonate is:

[0064]

[0065] According to expression (11), in the series of TE10q resonant modes, only TE101 mode can have single-mode resonance, and it can be determined that the necessary condition for resonating TE101 mode in the rectangular waveguide resonant cavity is:

[0066]

[0067] In rectangular waveguide matching loads, only the TE101 resonant mode is often used. In rectangular waveguides, the TE10 transmission mode is limited to λc=2a. From expressions (4), (5) and (12), it can be seen that the conditions for resonance in the rectangular resonant cavity and only one resonant mode, the TE101 mode, are:

[0068]

[0069] When the TE101 mode resonates in a rectangular resonant cavity, both the horizontal and vertical directions are standing waves, and there is no traveling wave.

[0070] (III) Derivation of the narrow side length b of the rectangular waveguide resonant cavity

[0071] In a rectangular waveguide, in order to ensure the maximum passing power under bandwidth, a=2b, which is also called a standard waveguide.

[0072] At this point, the derivation of the internal space dimension relationship equation (1) of the rectangular resonant cavity is completed.

[0073] In the rewarming and resuscitation of biological tissues, in order to achieve good penetration effect on larger tissues (generally referring to rectangular tissues with a side length of more than 30 mm, or spherical tissues with a diameter of more than 30 mm), experiments have shown that microwaves in the 430-440 MHz frequency band are required.

[0074] On the basis of the above embodiment, in order to achieve uniform radiation of microwave power in the 430-440 MHz frequency band, the wide side length a, narrow side length b and length side length l of the space in the rectangular resonant cavity need to satisfy a certain value range. For this reason, in one embodiment of the present application, the value ranges of the wide side length a, narrow side length b and length side length l are as follows:

[0075] 340.91mm≤a≤697.67mm,

[0076] 170.46mm≤b≤348.84mm,

[0077] 196.82mm≤l≤805.60mm.

[0078] In order to facilitate the understanding of the present invention, the calculation process of the above value range is briefly described below:

[0079] The wavelength range of microwaves in the 430-440 MHz frequency band is calculated according to the microwave wavelength formula λ=c / f; the obtained wavelength range is substituted into expression (8) to determine the value range of the wide side length a, and then according to a=2b, the value range of the narrow side length b is determined; the value range of the wide side length a is substituted into expression (12) to determine the value range of the length side length l.

[0080] Furthermore, according to the microwave frequency screening test of biological tissue, the present application found that 433MHz and 434MHz have better rewarming and resuscitation effects on biological tissue. Based on this experimental result, according to the volume formula V=a×b×l, the minimum volume value is screened with expression (13) (the microwave frequency is 433Mhz at this time), and the optimization is performed from the perspective of production convenience, and finally the size of the inner space of the rectangular resonant cavity is determined as:

[0081] The width length a is 500mm, the narrow side length b is 250mm, and the length side length l is 480mm;

[0082] In this preferred embodiment, in actual production, based on the size of the inner space of the rectangular resonant cavity, a metal plate with a thickness of 1.5 mm may be selected to manufacture the rectangular resonant cavity.

[0083] In microwave reheating technology, in order to realize the emission of microwave power, a microwave power emission antenna is required, but the microwave power antennas currently available on the market cannot meet the needs of actual use. Therefore, according to the characteristics of microwaves, the present invention uses HFSS software for simulation, and according to the actual processing capacity, designs the specific size structure of the microwave power emission antenna, which includes an antenna sleeve and an antenna core.

[0084] Specifically, in the above preferred embodiments, Figure 1 As shown, the antenna sleeve 20 is vertically connected to one end face of the rectangular resonant cavity 10 and is communicated with the interior of the rectangular resonant cavity 10 ; the end face to which the antenna sleeve 20 is connected is the end face where the wide side and the long side of the rectangular resonant cavity 10 are located.

[0085] like Figure 3a , Figure 3b As shown, the antenna sleeve 20 is a cylindrical sleeve with an inner radius of 45 mm and an inner space height of 102 mm. One end of the antenna sleeve 20 is open, and the other end is closed and provided with a central feeder hole 21.

[0086] It should be noted that the central feed hole 21 is used to pass the microwave feed line, and its shape and size are determined based on the wire specifications, for example, it is a circular hole with a radius of 5 mm. In actual production, the wall thickness of the antenna sleeve 20 can be selected to be 2 mm, and it is not difficult to understand that the material of the antenna sleeve 20 should be metal.

[0087] It should also be noted that in order to achieve communication between the antenna sleeve 20 and the interior of the rectangular resonant cavity 10, Figure 1 As shown, on the end face where the wide side and the length side of the rectangular resonant cavity 10 are located, a connecting hole 11 is provided at a distance of 140 mm from the left wide side of the space inside the rectangular resonant cavity and equidistant from the length sides of the inner space on both sides. The opening end of the antenna sleeve 20 is connected with the connecting hole 11 to realize the connection between the antenna sleeve 20 and the inside of the rectangular resonant cavity 10.

[0088] Specifically, the size of the communication hole 11 corresponds to the size of the opening end of the antenna sleeve, which is 45 mm here; and in order to facilitate the connection between the two, the opening end of the antenna sleeve and the communication hole are connected through a flange assembly.

[0089] like Figure 1 As shown, an antenna core 30 is coaxially arranged in the antenna sleeve 20, and the lower end of the antenna core 30 extends a certain length into the rectangular resonant cavity 10, while the upper end of the antenna core (30) extends into the central feed hole (21). A wave-transmitting material for fixing is filled between the antenna core 30 and the antenna sleeve 20 to ensure the positional relationship between the antenna core 30 and the antenna sleeve 20.

[0090] like Figure 1 and Figure 4 As shown, the antenna core 30 is a rotating body, and its appearance structure from top to bottom is composed of a truncated cone body 31, a transition truncated cone body 32 and a lower cylinder body 33. The material of the antenna core 30 is also metal, for example, its material is brass. Figure 4 As shown, the specific dimensions of the antenna core 30 are:

[0091] The height of the lower cylinder 33 is 70mm, and the bottom radius is 25mm (not shown in the figure); the height of the transition frustum body 32 is 60mm, the lower bottom radius is equal to the bottom radius of the lower cylinder 33, which is 25mm (not shown in the figure), and the upper bottom radius is 0.5mm (not shown in the figure); the upper bottom radius of the upper frustum body 31 is 0.45mm, the lower bottom radius is equal to the upper bottom radius of the transition frustum body 32, which is 0.5mm, and the height is 6mm (not shown in the figure).

[0092] In the field of rewarming and resuscitation biological tissue technology, the present invention proposes a specific emission and radiation structure for realizing microwave emission and radiation in the 433MHz frequency band and realizing the TE101 resonance mode, which provides strong support for solving the problem of microwave penetration in biological tissues and the problem of uniformity of heating inside and outside biological tissues.

[0093] In addition, experiments have shown that when the frequency of the microwaves fed in is 423-443Mhz, based on the structure of the preferred embodiment of the present invention, the structural dimensions are adjusted accordingly so that the height of the lower cylinder of the antenna core does not exceed 250mm, and the changes in the values ​​of other dimensions of the antenna core and the antenna sleeve do not exceed 50% of the original values, which can approximately achieve the rewarming and resuscitation effect on biological tissues in this embodiment of the present application.

[0094] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any person familiar with the technology within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A microwave power emitting radiation structure for rewarming and resuscitating biological tissues, characterized in that: Used to achieve microwave emission radiation in the frequency band of 430 to 440 MHz, comprising a rectangular resonant cavity (10), an antenna sleeve (20) being vertically connected to one end surface of the rectangular resonant cavity (10), and the antenna sleeve (20) being in communication with the interior of the rectangular resonant cavity (10); An antenna core (30) is also coaxially arranged in the antenna sleeve (20), the lower end of the antenna core (30) extends a certain length into the rectangular resonant cavity (10), and a wave-transmitting material for fixation is filled between the antenna core (30) and the antenna sleeve (20); The antenna core (30) is used to be connected to a microwave feed line to emit microwaves into a rectangular resonant cavity (10); the wide side length a, narrow side length b and long side length l of the space in the rectangular resonant cavity (10) satisfy the following relationship so that the microwaves realize a TE101 resonant mode: a=2b; The end surface to which the antenna sleeve (20) is connected is the end surface where the wide side and the length side of the rectangular resonant cavity (10) are located; the antenna sleeve (20) is a cylindrical sleeve with an inner radius of 45 mm and an inner space height of 102 mm; one end of the antenna sleeve (20) is open, and the other end is closed and provided with a central feeder hole (21); A connecting hole (11) is provided on the end surface at a distance of 140 mm from the wide side of the inner space of the rectangular resonant cavity (10) and equidistant from the long sides of the inner space on both sides; the open end of the antenna sleeve is cooperatively connected to the connecting hole (11) so that the antenna sleeve (20) is connected to the inside of the rectangular resonant cavity (10).

2. The structure according to claim 1, characterized in that: The width side length is greater than or equal to 340.91 mm and less than or equal to 697.67 mm; the length side length is greater than or equal to 196.82 mm and less than or equal to 805.60 mm.

3. The structure according to claim 2, characterized in that: The width side length is 500 mm, and the length side length is 480 mm.

4. The structure according to claim 1, characterized in that The open end of the antenna sleeve is connected to the communicating hole (11) through a flange assembly.

5. The structure according to claim 1, characterized in that: The radius of the central feed line hole (21) is 5 mm, and the upper end of the antenna core (30) extends into the central feed line hole (21).

6. The structure according to claim 5, characterized in that The appearance structure of the antenna core (30) is composed of an upper frustum (31), a transition frustum (32) and a lower cylinder (33) from top to bottom.

7. The structure according to claim 6, characterized in that The upper base radius of the upper frustum (31) is 0.45 mm, the lower base radius is 0.5 mm, and the height is 6 mm; the upper base radius of the transition frustum (32) is 0.5 mm, the lower base radius is 25 mm, and the height is 60 mm; the bottom radius of the lower cylinder (33) is 25 mm, and the height is 70 mm.

8. The structure according to any one of claims 1 to 7, characterized in that The material of the antenna core (30) is brass.

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