In-vivo liquid flow promotion device

Abstract

To provide an in-vivo liquid flow promotion device capable of safely and effectively promoting a liquid flow in a desired direction.SOLUTION: The device comprises: an ultrasonic vibrator 2 which generates ultrasonic waves; and an acoustic stream generation part 3 which adjusts the phase of the ultrasonic waves generated by the ultrasonic vibrator to converge it at a predetermined position and causes an in-vivo liquid at a convergence position to generate an acoustic flow by a pressure distribution generated according to the phase.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a device for promoting fluid flow in a living body. [Background technology]

[0002] It is known that promoting the flow of bodily fluids in the body can lead to disease treatment and health promotion. For example, in the case of blood, promoting blood circulation can be expected to improve stiff shoulders and cold sensitivity, and in the case of lymphatic fluid, promoting the flow can be expected to have a fatigue recovery effect by promoting the removal of waste products. Furthermore, in recent years, it has been suggested that promoting the flow of cerebrospinal fluid can also lead to disease treatment.

[0003] For example, many people around the world suffer from brain-related neurological disorders (depression, dementia, etc.). For example, antidepressants are a common treatment for depression, and they compensate for the lack of neurotransmitters, but since it is believed that there are other causes of the symptoms, there is a need to establish new drugs that act on these causes, or new treatment modalities that can replace drugs.

[0004] A new drug-free treatment method is to promote the flow of cerebrospinal fluid, which is the fluid that surrounds nerve cells in the brain. Cerebrospinal fluid is the fluid that surrounds nerve cells in the brain. In recent years, it has become clear that the brain actively flows cerebrospinal fluid during sleep to remove waste products. When this flow weakens due to aging, etc., it has been found that waste products accumulate around nerve cells, degenerating the cells themselves and causing dementia. In addition, it has been found that depression is also related to the deterioration of the flow of cerebrospinal fluid, and it has been suggested that improving the flow may improve symptoms. Furthermore, it has been found to be related to sleep quality and brain aging. Therefore, if the flow of cerebrospinal fluid can be controlled and promoted from the outside, it may be possible to prevent and treat brain neurological diseases (depression, dementia), and even alleviate brain aging.

[0005] Patent Document 1 discloses that cerebrospinal fluid is locally expanded by thermal energy generated by irradiating a specific location in the brain with sound waves, thereby inducing convection and promoting fluid flow. However, the technology of Patent Document 1 needs to be implemented while suppressing side effects caused by fever, and there is a problem in that it is not possible to safely and effectively promote fluid flow. In addition, since the expansion occurs isotropically, a force is applied in a direction that does not promote fluid flow, which may cause cerebrospinal fluid to flow backwards. Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide an in vivo fluid flow promoting device that can safely and effectively promote fluid flow in a desired direction. [Means for solving the problem]

[0007] One aspect of the present invention is an in vivo fluid flow promotion device comprising an ultrasonic transducer that generates ultrasonic waves, and an acoustic streaming generator that adjusts the phase of the ultrasonic waves generated by the ultrasonic transducer to focus the ultrasonic waves at a predetermined position, and generates acoustic streaming in the in vivo fluid at the focused position by a pressure distribution generated in accordance with the phase. Effect of the Invention

[0008] The present invention can provide an in vivo fluid flow promoting device that can safely and effectively promote fluid flow in a desired direction. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing a first embodiment of a biological fluid flow promoting device according to the present invention; [Diagram 2] FIG. 2 is a partial cross-sectional view of the device 1 for promoting fluid flow in a living body. [Diagram 3] FIG. 1 is a schematic diagram showing the flow of cerebrospinal fluid in the brain. [Figure 4] 11 is a cross-sectional view of an acoustic refraction member 3G according to a second embodiment. FIG. [Diagram 5]13 is a perspective view of the acoustic refraction member 3G as seen from the focal position S side. FIG. [Figure 6] 1 is a diagram showing the pressure distribution in the X direction of ultrasonic waves focused at a focusing position S. FIG. [Figure 7] 1 is a diagram showing the pressure distribution in the Y direction of ultrasonic waves focused at a focusing position S. FIG. [Figure 8] 1 is a diagram showing the pressure distribution in the XY plane of ultrasound focused at a focal position S. FIG. [Figure 9] FIG. 1 shows an example of an experiment in which ultrasound is focused on a liquid. [Figure 10] FIG. 11 is a perspective view of an acoustic refraction member 3M according to the third embodiment. [Figure 11] 1 is a vector diagram showing how the acoustic refraction member 3M generates a driving force in space. [Figure 12] FIG. 12 is an enlarged side view of a portion of FIG. [Figure 13] FIG. 11 is a schematic diagram showing a fourth embodiment of the device for promoting fluid flow in a living body according to the present invention. [Figure 14] FIG. 13 is a diagram showing an example of use of the biological fluid flow promoting device. [Figure 15] FIG. 13 is a diagram showing an example of use of the biological fluid flow promoting device. [Figure 16] FIG. 13 is a diagram showing an example of use of the biological fluid flow promoting device. [Figure 17] FIG. 13 is a diagram showing an example of use of the biological fluid flow promoting device. [Figure 18] FIG. 13 is a diagram showing an example of use of the biological fluid flow promoting device. [Figure 19] FIG. 13 is a diagram showing an example of use of the biological fluid flow promoting device. [Figure 20] FIG. 13 is a diagram showing an example of use of the biological fluid flow promoting device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] BEST MODE FOR CARRYING OUT THE DISCLOSURE Hereinafter, an embodiment of the device for promoting fluid flow in a living body according to the present invention will be described with reference to Figs. The following embodiment shows one aspect of the present invention, does not limit the present invention, and can be modified as desired within the scope of the technical idea of ​​the present invention. In addition, in the following drawings, the scale and number of each structure are different from the actual structure in order to make each configuration easier to understand.

[0011] [First embodiment of the biological fluid flow promoting device] FIG. 1 is a schematic diagram showing the configuration of a first embodiment of a biological fluid flow promoting device according to the present invention. The biological fluid flow promoting device 1, attached to the living body H, focuses and irradiates ultrasonic waves at a predetermined position inside the body, thereby generating an acoustic flow at the ultrasonic focus position S, and promoting the flow of the biological fluid in a direction along the flow of the biological fluid. "Along the flow of the biological fluid" means having a vector in the direction of travel of the biological fluid. The "predetermined position" is a specific position in the path through which the biological fluid flows within the living body, and can be set appropriately depending on the desired effect. In FIG. 1, the biological fluid flow promoting device 1 is attached to the head, and the focus position S is set inside the head (inside the brain).

[0012] As shown in FIG. 1, the biological fluid flow enhancing device 1 includes an ultrasonic transducer 2, an acoustic flow generating unit 3, and a guide member 4.

[0013] The ultrasonic transducer 2 generates ultrasonic waves in the direction in which the axis J extends. The ultrasonic transducer 2 is housed inside a cylindrical cover 2A. Fig. 2 is a partial cross-sectional view of the biological fluid flow promoting device 1. As shown in Fig. 2, the ultrasonic transducer 2 has a vibration surface 2B at the tip on the focal position S side.

[0014] The acoustic streaming generator 3 adjusts the phase of the ultrasonic waves generated by the ultrasonic transducer 2 and focuses the ultrasonic waves at a predetermined position. The axis J is an imaginary line extending from an acoustic refraction member 3D (described later) of the acoustic refraction member 3 toward the focusing position S. Since the ultrasonic waves emitted from the ultrasonic transducer 2 travel in a direction along the axis J (the direction from the acoustic refraction member 3D toward the focusing position S), this direction may be referred to as the "traveling direction" in the following description.

[0015] The acoustic streaming generator 3 has a cylindrical protrusion 3F on the side facing the focusing position S. The acoustic streaming generator 3 has a circular recess 3A on the side opposite the focusing position S. The tip of the cover 2A of the ultrasonic transducer 2 on the side facing the focusing position S is inserted into the recess 3A. The peripheral surface 3B of the recess 3A fits into the outer periphery of the cover 2A. The bottom surface 3C of the recess 3A is in surface contact with the vibration surface 2B of the ultrasonic transducer 2. The acoustic streaming generator 3 transmits ultrasonic waves generated by the ultrasonic transducer 2 via the vibration surface 2B and the bottom surface 3C.

[0016] The acoustic streaming generating unit 3 of this embodiment adjusts the phase of the ultrasonic waves, which is uniform in the circumferential direction about the axis J, and in the radial direction about the axis J, the direction toward the focal position S is set as the traveling direction. The acoustic streaming generating unit 3 of this embodiment has an acoustic refraction member 3D. The acoustic refraction member 3D has a concave surface 3E on the side facing the focal position S. The concave surface 3E has a curved shape for focusing the ultrasonic waves at a target position. When the axis J is set at the center of the acoustic refraction member 3D in a plan view, the concave surface 3E curves in the direction toward the focal position S in the traveling direction as it moves toward the outside in the radial direction centered on the axis J extending in the traveling direction. The concave surface 3E is a spherical surface recessed from the surface of the acoustic refraction member 3D facing the focal position S. The acoustic refraction member 3D refracts the ultrasonic waves incident from the ultrasonic transducer 2 at the concave surface 3E, and sets the traveling direction to the focal position S.

[0017] The material of the acoustic refraction member 3D is, for example, silicone rubber, and PDMS (polydimethylsiloxane) silicone rubber is used. The acoustic impedance of PDMS is almost the same as that of water, which allows ultrasonic waves to propagate more effectively.

[0018] The guide member 4 has a recess 4A, a storage portion 4B, and a joint portion 4C. The recess 4A is circular, and is located on the opposite side of the guide member 4 from the focusing position S. The protrusion 3F of the acoustic streaming generator 3 is inserted and fitted into the recess 4A. The guide member 4 is made of silicone rubber or a resin material with high hardness.

[0019] The storage section 4B penetrates the guide member 4 along the axis J. The storage section 4B is a circular through-hole centered on the axis J. The storage section 4B opens toward the focusing position S. The diameter of the storage section 4B is larger than the diameter of the concave surface 3E. The concave surface 3E is formed facing the storage section 4B. The storage section 4B is capable of storing and holding a propagation liquid 5 through which ultrasonic waves propagate. As the propagation liquid 5, water or a gel used in general ultrasound examinations is suitable.

[0020] The joint 4C is a region of the guide member 4 facing the focusing position S. The joint 4C surrounds the storage section 4B. The joint 4C is joined to the living body H. In this embodiment, the joint 4C is joined from the forehead to the nose of the living body H, as an example. When the joint 4C is joined to the living body H, the storage section 4B is sealed. When the joint 4C is joined to the living body H, the propagation medium 5 is held in a state of being filled in the storage section 4B. When the joint 4C is joined to the living body H, the joint 4C defines the focusing position S as a target position. In other words, the guide member 4 is formed into a shape that defines the focusing position S as a target position when the joint 4C is joined to the living body H.

[0021] Although there is no particular limitation on the method for producing the guide member 4, it is preferable to obtain facial shape data of the subject by 3D scanning, and use the obtained facial shape data to produce the guide member 4, for example, with a general-purpose 3D printer. By adopting this method, the subject can easily position the in vivo fluid flow promoting device 1 on the face and use it.

[0022] To promote fluid flow in a living body H using the living body fluid flow promoting device 1 having the above-mentioned configuration, the joint 4C of the guide member 4 is joined to the face of the subject, which is the living body H. Then, the ultrasonic transducer 2 generates ultrasonic waves. The generated ultrasonic waves are irradiated from the forehead of the subject via the vibration surface 2B, the bottom surface 3C, the concave surface 3E, and the transmitting liquid 5.

[0023] Here, if there is hair, the ultrasonic waves cannot propagate to the inside of the brain, so it is necessary to shave the head. Shaving the head is mentally stressful for the subject, and is preferably avoided. In this embodiment, the ultrasonic waves are irradiated from the forehead, so shaving is not required, which is excellent in practical use. As for the irradiation position, even if hair shaving is required, irradiation may be performed from a location where there is hair, for example, as long as it can promote the flow of liquid in the living body H.

[0024] Ultrasound emitted from the subject's forehead is focused at focusing position S as shown in Figure 1 in the direction of propagation set by the acoustic refraction member 3D, and an acoustic stream is generated in the direction along which axis J extends due to the pressure distribution generated according to the adjusted phase.

[0025] FIG. 3 is a schematic diagram showing the flow of cerebrospinal fluid within the brain. As shown in Fig. 3, it is believed that cerebrospinal fluid 10 seeps out from the choroid plexus, flows through the brain, is absorbed by arachnoid granulations, and flows into the superior sagittal sinus, which is a blood vessel in the brain. In Fig. 3, the original flow direction of cerebrospinal fluid 10 is indicated by an arrow. In other figures described below, the flow direction of cerebrospinal fluid is also indicated by an arrow in schematic diagrams similar to or corresponding to Fig. 3.

[0026] The flow of cerebrospinal fluid 10, which is a biological fluid in the brain, seeps out from the choroid plexus of the lateral ventricle, advances to the third ventricle, passes through the cerebral aqueduct, and reaches the fourth ventricle. After that, it advances to the subarachnoid space, which is the gap between the brain and the arachnoid membrane that covers the entire brain, and some of it advances toward the back of the head, while some of it goes around the periphery of the spinal cord and advances forward toward the frontal lobe.

[0027] Ultrasound emitted from the in vivo fluid flow promotion device 1 is emitted with the vicinity of the entrance of the cerebral aqueduct as the target position (predetermined position) of focal position S. An acoustic stream generated at focal position S by the irradiation of ultrasound is generated inside the third ventricle along axis J toward the downstream cerebral aqueduct, promoting the fluid flow in line with the original flow. Note that the direction of irradiation (direction along axis J) does not need to be completely parallel to the original flow direction of cerebrospinal fluid 10. It is sufficient that the direction of irradiation includes a vector component in the direction of the fluid flow.

[0028] In this case, it is preferable from the viewpoint of stably promoting the liquid flow that the direction of ultrasound irradiation (direction along the axis J) is approximately -60° or more and +60° or less with respect to the flow direction of the cerebrospinal fluid 10. In addition, the power of ultrasound irradiation is 10 w / cm at the highest part at the focal position S. 2 This range can be empirically used as a safe range.

[0029] Furthermore, the promotion of the flow of the cerebrospinal fluid 10 can be confirmed, for example, by observing the flow of the cerebrospinal fluid 10 at the focal position S (target position) using MRI (Magnetic Resonance Imaging).

[0030] As described above, in the biological fluid flow promotion device 1 of this embodiment, the phase of the ultrasound generated by the ultrasonic transducer 2 is adjusted to focus the ultrasound and generate acoustic flow in the biological fluid at the focusing position S, so there is no need to suppress side effects caused by heat generation, as in the case of promoting fluid flow using convection generated by locally expanding cerebrospinal fluid with thermal energy.

[0031] Therefore, in the biological fluid flow promoting device 1 of the present embodiment, the flow of cerebrospinal fluid 10 in the brain can be promoted safely and effectively, and the effect of promoting the removal of waste products can be obtained. Furthermore, in the biological fluid flow promotion device 1 of this embodiment, the flow of biological fluid is promoted by acoustic streaming, so that the flow of fluid can be promoted in the desired direction without causing backflow, as occurs when cerebrospinal fluid is locally expanded.

[0032] [Second embodiment of the biological fluid flow promoting device] Next, a second embodiment of the device 1 for promoting fluid flow in a living body will be described with reference to Figures 4 to 9. In these figures, the same components as those in the first embodiment shown in Figures 1 to 3 are designated by the same reference numerals, and the description thereof will be omitted. The device 1 for enhancing fluid flow in a living body according to the second embodiment differs from that according to the first embodiment in the configuration of the acoustic refraction member.

[0033] The device 1 for promoting fluid flow in a living body includes an acoustic flow generating section 3 which is an acoustic refraction member 3G. Fig. 4 is a cross-sectional view of the acoustic refraction member 3G, and Fig. 5 is a perspective view of the acoustic refraction member 3G as viewed from the focal position S side.

[0034] As shown in FIG. 4, the acoustic refraction member 3G has a groove 3J recessed from a surface 3H facing the focusing position S. The radial cross section of the groove 3J is V-shaped. The V-shaped groove 3J is formed by an inclined surface 3K and a vertical surface 3L. When an axis J is set at the center of the acoustic refraction member 3G in a plan view, the inclined surface 3K inclines in a radially inward direction centered on the axis J as it moves away from the surface 3H. The vertical surface 3L is perpendicular to the surface 3H and extends in a direction away from the surface 3H. The inclined surfaces 3K and the vertical surface 3L that form adjacent grooves 3J in the radial direction intersect at the position of the surface 3H in the direction along the axis J.

[0035] When viewed from the focusing position S side, the inclined surface 3K is arranged in a spiral shape extending in a direction toward one side in the circumferential direction centered on the axis line J as it moves radially outward from the axis line J. The inclined surface 3K is arranged in a spiral shape extending in a clockwise direction as it moves radially outward. The inclined surface 3K may be configured to be arranged in a spiral shape extending in a counterclockwise direction as it moves radially outward.

[0036] The inclined surfaces 3K are arranged at predetermined intervals in the circumferential direction. Four inclined surfaces 3K are arranged at 90° intervals in the circumferential direction.

[0037] Fig. 6 is a diagram showing experimental results of pressure distribution (pressure field) in the X direction of ultrasonic waves focused at focusing position S, when the X direction and Y direction are parallel to face 3H and perpendicular to each other in acoustic refraction member 3G. Fig. 7 is a diagram showing experimental results of pressure distribution (pressure field) in the Y direction of ultrasonic waves focused at focusing position S. Fig. 8 is a diagram showing numerical simulation results of pressure distribution (pressure field) in the XY plane of ultrasonic waves focused at focusing position S.

[0038] As shown in Figure 6, it was confirmed that at the focusing position S, there is a place where the pressure is high at a position with a radius of 3 mm on the +X side from the axis J where measurements were taken in the X direction. It can also be inferred that there is a similar place where the pressure is high at a position with a radius of 3 mm on the -X side from the axis J where measurements were not taken. Similarly, as shown in Figure 7, it was confirmed that there are places where the pressure is high at a radius of 3 mm from the axis J on both sides in the Y direction. From the results of this experiment, it is inferred that a ring-shaped pressure field is formed as shown in Figure 8.

[0039] Furthermore, as shown in FIG. 8, at the ultrasonic focal position S, a circumferential pressure distribution is generated in which the pressure of the pressure field is greatest on the X-axis and Y-axis and decreases as it progresses in the clockwise direction.

[0040] Therefore, by generating a pressure distribution in the circumferential direction centered on the axis J at the focal position S of the ultrasonic waves, it is possible to generate an acoustic stream in the circumferential direction. Therefore, a force in a rotational direction acts on the cerebrospinal fluid 10 located at the focusing position S in accordance with the pressure distribution in the circumferential direction about the axis J, thereby generating a vortex flow.

[0041] 9 is a diagram showing an example of an experiment in which ultrasonic waves are focused on liquid using an acoustic refraction member 3G. As shown by the arrow in FIG. 9, it was possible to observe that clockwise rotation occurred in the liquid.

[0042] In the biological fluid flow promoting device 1 of this embodiment, in addition to obtaining the same actions and effects as those of the first embodiment described above, it is possible to generate an acoustic flow in a rotational direction in the biological fluid, thereby further promoting the liquid flow.

[0043] [Third embodiment of the biological fluid flow promoting device] Next, a third embodiment of the device 1 for promoting fluid flow in a living body will be described with reference to Fig. 10 to Fig. 12. In these figures, the same components as those in the first embodiment shown in Fig. 1 to Fig. 8 are denoted by the same reference numerals, and the description thereof will be omitted or simplified. The device 1 for enhancing fluid flow in a living body according to the third embodiment differs from that according to the first embodiment in the configuration of the acoustic refraction member.

[0044] The device 1 for promoting fluid flow in a living body has an acoustic flow generating section 3 which is an acoustic refraction member 3M. Fig. 10 is a perspective view of the acoustic refraction member 3M. Fig. 11 is a vector diagram showing how the acoustic refraction member 3M generates a driving force in space. Fig. 12 is an enlarged side view of a portion of Fig. 11.

[0045] As shown in Fig. 10, the acoustic refraction member 3M in this embodiment has an inner peripheral surface 13A and an outer peripheral surface 13B. The inner peripheral surface 13A and the outer peripheral surface 13B are peripheral surfaces centered on a second axis J2 that is perpendicular to an imaginary plane S1 including the axis J in a plan view. The second axis J2 is perpendicular to each of the three axes J shown in Fig. 10. The acoustic refraction member 3M has an inner peripheral surface 13A formed in an arc shape facing the focusing position S.

[0046] The ultrasonic waves traveling through the acoustic refraction member 3M having the above-mentioned configuration are focused at a focusing position S when viewed from the second axis J2. On the other hand, when viewed from a lateral direction perpendicular to the second axis J2, the ultrasonic waves emitted from the inner circumferential surface 13A are not focused because they travel perpendicular to the generating line parallel to the second axis J2.

[0047] Therefore, as shown in Fig. 11, the driving force vector of the ultrasonic wave emitted from the acoustic refraction member 3M travels from the upper right to the lower left, but the driving force vectors are aligned in parallel in the direction along the second axis J2 as shown in Fig. 12. In this case, the component of the driving force vector traveling to the left in the figure is generated in a straight line, as shown by the arrow surrounded by a two-dot chain line square.

[0048] In the biological fluid flow promoting device 1 of this embodiment, in addition to obtaining the same actions and effects as those of the first embodiment described above, by irradiating the area where it is desired to generate a linear flow, it is possible to effectively promote the fluid flow.

[0049] [Fourth embodiment of the biological fluid flow promoting device] Next, a fourth embodiment of the device 1 for promoting fluid flow in a living body will be described with reference to Fig. 13. In this figure, the same components as those in the first embodiment shown in Figs. 1 to 3 are given the same reference numerals, and their description will be omitted or simplified. The biological fluid flow enhancing device 1 of the third embodiment differs from the first embodiment in the configurations of the ultrasonic transducer 2, acoustic flow generating section 3 and guide member 4.

[0050] FIG. 13 is a schematic diagram showing the configuration of a fourth embodiment of the device 1 for promoting fluid flow in a living body. 13, the guide member 4 in this embodiment is provided at the tip of the cover 2A on the focusing position S side. The guide member 4 has a container portion 4B, a joint portion 4C, and a cup portion 4D. The cup portion 4D is cup-shaped with a diameter expanding from the tip of the cover 2A toward the living body H. The joint portion 4C is provided at the tip of the cup portion 4D. In addition, the container portion 4B is provided inside the cup portion 4D.

[0051] The ultrasonic transducer 2 is, for example, several mm in size. A plurality of ultrasonic transducers 2 are arranged at a position facing the storage section 4B. Each of the plurality of ultrasonic transducers 2 can independently generate ultrasonic waves. The ultrasonic transducers 2 are arranged in an array at the tip of the cover 2A facing the storage section 4B. The ultrasonic transducers 2 are arranged in an array on the inner peripheral surface of the cup section 4D facing the storage section 4B.

[0052] The acoustic streaming generator 3 has a controller 3N. The controller 3N individually controls the phase of the ultrasonic waves generated by the multiple ultrasonic transducers 2. By the controller 3N individually controlling the phase of the ultrasonic waves generated by the multiple ultrasonic transducers 2, acoustic streaming can be generated by a pressure distribution generated according to the phase.

[0053] For example, the control unit 3N can individually control the phase of the ultrasound generated by the ultrasound transducer 2 to generate a pressure distribution similar to the pressure distribution generated by the concave surface 3E of the acoustic refraction member 3D shown in Figure 2, thereby focusing the ultrasound in a point-like manner at the focusing position S.

[0054] Furthermore, the control unit 3N can individually control the phase of the ultrasound generated by the ultrasonic transducer 2 to generate a pressure distribution that is the same as or similar to the pressure distribution shown in Figure 8 generated by the inclined surface 3K of the acoustic refraction member 3G shown in Figures 4 and 5, thereby generating an acoustic flow in which a rotational force acts in accordance with the circumferential pressure distribution, generating a vortex flow.

[0055] Furthermore, the control unit 3N can individually control the phase of the ultrasound generated by the ultrasonic transducer 2 to generate a pressure distribution that is the same as or similar to the pressure distribution that generates the driving force vectors shown in Figures 11 and 12, thereby generating an acoustic stream that generates a linear flow.

[0056] [Example of use of the biological fluid flow promotion device 1] FIG. 14 is a diagram showing an example of use of the biological fluid flow promoting device 1. In the first embodiment, as shown in Fig. 3, ultrasonic waves are irradiated to the vicinity of the entrance of the cerebral aqueduct as the target position of the focal position S. As shown in Fig. 14, by irradiating ultrasonic waves from the forehead to the subarachnoid space as the focal position S, the flow from the front to the back of the head can be promoted.

[0057] 15 and 16 are diagrams showing an example of use of another device 1 for promoting fluid flow in a living body. In the first embodiment, as shown in Fig. 3, ultrasonic waves were applied from the forehead using the biological fluid flow promoting device 1. As shown in Fig. 15 and Fig. 16, a configuration may be adopted in which multiple biological fluid flow promoting devices 1 are used and ultrasonic waves are applied from the left and right temples in addition to the forehead. By adopting this configuration, the fluid flow effect can be further enhanced. In this case, the focal position S may be the same, or a plurality of in vivo fluid flow promotion devices 1 may be configured to irradiate ultrasonic waves to focal positions S at different positions.

[0058] 17 and 18 are diagrams showing an example of use of another biological fluid flow promoting device 1. In FIG. In the second embodiment, an example has been given of a configuration in which ultrasonic waves are irradiated to the vicinity of the entrance of the cerebral aqueduct as the target position of the focal position S, and a rotational force is applied to the cerebrospinal fluid 10 to generate a vortex flow. As shown in Fig. 17, ultrasonic waves may be irradiated from the vicinity of the temples by the biological fluid flow promoting device 1 described in the second embodiment, and as shown in Fig. 18, ultrasonic waves may be irradiated to the third ventricle as the target position of the focal position S from the vicinity of the temples. By adopting this configuration, a rotating flow of the cerebrospinal fluid 10 can be generated in the third ventricle, which can promote the inflow of the cerebrospinal fluid 10 from the lateral ventricle.

[0059] 19 and 20 are diagrams showing an example of use of another device 1 for promoting fluid flow in a living body. In the second embodiment, a configuration has been exemplified in which one biological fluid flow promoting device 1 is used to apply a rotational force to the cerebrospinal fluid 10 to generate a vortex flow. As shown in Fig. 19, two biological fluid flow promoting devices 1 are arranged on the left and right sides of the center of the forehead. The two biological fluid flow promoting devices 1 rotate in opposite directions to apply a force to the cerebrospinal fluid 10 to generate a vortex flow. By adopting this configuration, it is possible to generate a straight flow of cerebrospinal fluid 10 in the central portion between the two biological fluid flow promoting devices 1. With this configuration, it is possible to promote the flow of cerebrospinal fluid 10 flowing in the shallow portion of the forehead, as shown in FIG.

[0060] In addition, the example of use of the in vivo fluid flow promoting device 1 described using Figures 14 to 20 can also be used using the in vivo fluid flow promoting device 1 described as the fourth embodiment using Figure 13. In other words, by controlling the phase of the ultrasound generated by the multiple ultrasonic transducers 2 using the control unit 3N, in each of the usage examples of the biological fluid flow promotion device 1 described using Figures 14 to 20, a pressure distribution can be generated that is the same as or similar to the pressure distribution generated in accordance with the phase adjusted by the acoustic flow generating unit 3, thereby obtaining similar usage results.

[0061] Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to the examples. The shapes and combinations of the components shown in the above examples are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

[0062] In the above embodiment, the configuration in which the fluid in the living body is the cerebrospinal fluid 10 is exemplified, but the present invention is not limited to this configuration. In addition to the cerebrospinal fluid 10, examples of the fluid in the living body include blood and lymphatic fluid. In particular, blood has an effect of promoting blood circulation, while lymphatic fluid and cerebrospinal fluid have an effect of removing waste products.

[0063] In the above embodiment, the in vivo fluid flow promoting device 1 is configured to irradiate the ultrasonic wave to the head of the living body H, but is not limited to this configuration. The position of the living body H to be irradiated when obtaining the fluid flow promoting effect of the cerebrospinal fluid 10 may be, for example, a spine, in addition to the head.

[0064] Moreover, the location on the living body H to which the biological fluid flow enhancing device 1 irradiates ultrasonic waves is preferably at least one of the face, the neck area, and the back. By adopting this configuration, the effect of promoting the flow of cerebrospinal fluid 10 is obtained without the need for shaving the subject's head, which reduces the psychological stress of the subject.

[0065] The present invention includes the following aspects. [1] An apparatus for promoting fluid flow in a living body, comprising: an ultrasonic transducer that generates ultrasonic waves; and an acoustic streaming generator that adjusts the phase of the ultrasonic waves generated by the ultrasonic transducer to focus the waves at a predetermined position, and generates acoustic streaming in the biological fluid at the focused position using a pressure distribution generated in accordance with the phase. [2] The acoustic flow generating unit has an acoustic refraction member. The device for promoting fluid flow in a living body as described in [1] above. [3] The acoustic refraction member has a concave surface that curves in a direction toward the focusing position as it extends radially outward from the acoustic refraction member toward the focusing position, The device for promoting fluid flow in a living body as described in [2] above. [4] The acoustic refraction member has an inclined surface that inclines in a radially inward direction about an axis extending from the acoustic refraction member toward the focusing position as it moves away from a surface facing the focusing position, and the inclined surface is arranged in a spiral shape extending in a direction toward one side in a circumferential direction about the axis as it moves from the axis toward the radially outward direction. The device for promoting fluid flow in a living body as described in [2] above. [5] The acoustic refraction member has an inner circumferential surface and an outer circumferential surface centered on a second axis perpendicular to a virtual plane including an axis extending from the acoustic refraction member toward the focusing position, the inner circumferential surface being formed in an arc shape facing the focusing position. The device for promoting fluid flow in a living body as described in [2] above. [6] A plurality of the ultrasonic transducers are arranged in an array, and the acoustic streaming generating unit has a control unit that individually controls the phases of the ultrasonic waves generated by the plurality of ultrasonic transducers. The device for promoting fluid flow in a living body as described in [1] above. [7] A guide member having a container that opens toward the focal position and contains a propagation liquid through which the ultrasonic waves propagate, and a joint that surrounds the container and defines the focal position as a target position when joined to a living body. The device for promoting fluid flow in a living body described in any one of [1] to [6]. [Explanation of symbols]

[0066] 1. Device for promoting fluid flow in the body 2 Ultrasonic transducer 3 Acoustic flow generation section 3D, 3G, 3M acoustic refractive materials 3E concave 3K sloped surface 4 Guide member 4B Storage section 4C joint 5. Propagation fluid 13A Inner surface 13B Outer surface H. Living body J axis J2 2nd axis S Focusing position [Prior art documents] [Patent documents]

[0067] [Patent Document 1] Patent No. 6585836

Claims

1. An ultrasonic transducer that generates ultrasonic waves; an acoustic streaming generator that adjusts a phase of the ultrasonic waves generated by the ultrasonic transducer to focus the ultrasonic waves at a predetermined position and generates acoustic streaming in the biological fluid at the focused position according to a pressure distribution generated in accordance with the phase; An apparatus for promoting fluid flow in a living body comprising:

2. The acoustic flow generating unit has an acoustic refraction member. The device for promoting fluid flow in a living body according to claim 1.

3. The acoustic refraction member has a concave surface that curves in a direction toward the focusing position as it extends radially outward from the acoustic refraction member about an axis extending from the acoustic refraction member toward the focusing position. The device for promoting fluid flow in a living body according to claim 2.

4. The acoustic refraction member has an inclined surface that is inclined in a radially inward direction about an axis extending from the acoustic refraction member toward the focusing position as the inclination increases with distance from the surface facing the focusing position, The inclined surfaces are arranged in a spiral shape extending in a direction toward one side in a circumferential direction centered on the axis line as they move outward in the radial direction from the axis line. The device for promoting fluid flow in a living body according to claim 2.

5. The acoustic refractive member is The acoustic refraction member has an inner circumferential surface and an outer circumferential surface, the inner circumferential surface being centered on a second axis line that is located on the focal position side and is perpendicular to a virtual plane that includes an axis line extending from the acoustic refraction member toward the focal position, The inner circumferential surface is formed in an arc shape facing the focusing position. The device for promoting fluid flow in a living body according to claim 2.

6. The ultrasonic transducers are arranged in a plurality of arrays, The acoustic streaming generator has a control unit that individually controls the phases of the ultrasonic waves generated by the plurality of ultrasonic transducers. The device for promoting fluid flow in a living body according to claim 1.

7. The guide member includes a container that opens toward the focal position and contains a propagation liquid through which the ultrasonic waves propagate, and a joint that surrounds the container and defines the focal position as a target position when joined to a living body. The device for promoting fluid flow in a living body according to any one of claims 1 to 6.

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