WO2013062118A1

WO2013062118A1 - Fat removal device

Info

Publication number: WO2013062118A1
Application number: PCT/JP2012/077812
Authority: WO
Inventors: Miyuki Murakami
Original assignee: Olympus Corporation
Priority date: 2011-10-26
Filing date: 2012-10-22
Publication date: 2013-05-02
Also published as: JP2013090809A

Abstract

Fatty tissue is removed while preventing heat from being transferred to surrounding tissue. Provided is a fat removal device (100) including a substantially tubular housing (10) having an opening (10a) that is pressed onto fatty tissue (A); an ultrasonic element (20) that is accommodated in the housing (10) and radiates focused ultrasonic waves onto a surface of the fatty tissue (A) exposed within the housing (10) due to being pressed by the opening (10a); and a feed tube (30) that feeds a fluidic propagation material (W), through which the ultrasonic waves propagate, into the housing (10). The housing (10) has a reservoir chamber (12) that is located between the ultrasonic element (20) and the surface of the fatty tissue (A) exposed within the housing (10) through the opening (10a) and that is filled with the propagation material (W) fed from the feed tube (30).

Description

.{ DESCRIPTION}

{Title of Invention}

FAT REMOVAL DEVICE

{Technical Field}

{0001}

The present invention relates to fat removal devices. {Background Art}

{0002}

In the related art, a fat removal device that removes fatty tissue inside a patient's body by using focused

ultrasonic waves is known (for example, see Patent Literature 1) . The fat removal device discussed in Patent Literature 1 radiates the focused ultrasonic waves from outside the

patient's body to a focal point in the fatty tissue inside the body, thereby dissolving the fatty tissue with the heat generated by the focused ultrasonic waves.

{Citation List}

{Patent Literature}

{0003}

{ PTL 1}

Japanese Unexamined Patent Application, Publication No. 2008- 212708

{Summary of Invention}

{Technical Problem}

{0004} However, if the fatty tissue adhered to an organ is to be removed by using the fat removal device discussed in Patent Literature 1, there is a problem in that the heat generated by the ultrasonic waves is transferred to tissue surrounding the fatty tissue since the fat removal device discussed in Patent Literature 1 cannot physically remove an area surrounding the focal point on the fatty tissue from that location.

{0005}

The present invention has been made in view of the circumstances described above, and an object thereof is to provide a fat removal device that can remove fatty tissue while preventing heat from being transferred to surrounding tissue.

{Solution to Problem}

{0006}

In order to achieve the aforementioned object, the present invention provides the following solutions.

A first aspect of the invention provides a fat removal device including a substantially tubular housing having an opening that is pressed onto fatty tissue; an ultrasonic element that is accommodated in the housing and radiates a focused ultrasonic wave onto a surface of the fatty tissue exposed within the housing due to being pressed by the

opening; and a feed tube that feeds a fluidic propagation material, through which the ultrasonic wave propagates, into the housing. The housing has a reservoir chamber that is located between the ultrasonic element and the surface of the fatty tissue exposed within the housing through the opening and that is filled with the propagation material fed from the feed tube.

{0007}

According to this aspect, the opening is pressed onto the fatty tissue adhered to an organ, etc. of a living organism so as to expose the surface of the fatty tissue within the housing, thereby forming the reservoir chamber that can retain the propagation material within the housing. In this state, the reservoir chamber is filled with the propagation material via the feed tube, and the ultrasonic element generates an ultrasonic wave, whereby the surface of the fatty tissue exposed within the housing is irradiated with the ultrasonic wave via the propagation material.

{0008}

When the ultrasonic wave is radiated to a focal point on the surface of the fatty tissue, negative pressure is

generated in an area on the surface of the fatty tissue that coincides with the focal point of the ultrasonic wave so that a bubble nucleus contained in the propagation material grows, thus causing cavitation. Thus, the fatty tissue irradiated with the ultrasonic wave becomes dissolved or fragmented so as to become detached from the organ, etc. {0009}

In this case, acoustic streaming occurs in the

propagation material due to the nonlinear properties of the ultrasonic wave. Because the sonic speed of the acoustic streaming reaches a maximum when the sound pressure of the ultrasonic wave is at the highest level, that is, at the focal point of the ultrasonic wave, the fatty tissue detached from the organ, etc. due to the cavitation can be removed by the acoustic streaming. Moreover, the area from which the fatty tissue is detached can be cooled by a water-cooling effect of the acoustic streaming. Consequently, the fatty tissue can be removed while preventing the heat generated by the ultrasonic wave from being transferred to surrounding tissue.

{0010}

A second aspect of the invention provides a fat removal device including a substantially tubular housing having an opening that is pressed onto fatty tissue; an ultrasonic element that is accommodated in the housing and radiates a focused ultrasonic wave onto a surface of the fatty tissue exposed within the housing due to being pressed by the

opening; and a feed tube that feeds a fluidic propagation material into the housing. The housing includes a partition member that has acoustic transmission characteristics and partitions the housing into an opening region filled with the propagation material fed from the feed tube and a ultrasonic- element region filled with the propagation material in advance.

{0011}

According to this aspect, the ultrasonic element is double-insulated by the housing and the partition member from the surface of the fatty tissue that is to be disposed adjacent to the opening, thereby allowing for improved electrical safety. Furthermore, the space within the housing filled with the propagation material fed from the feed tube can be reduced, due to the ultrasonic-element region, as compared with a case where the entire region from the surface of the fatty tissue to the ultrasonic element is used. Thus, the floating period of a bubble nucleus contained in the propagation material fed from the feed tube is reduced, thereby allowing for improved cavitation generation

efficiency. Furthermore, the propagation material can be made to circulate readily, so that the fatty tissue detached from the organ, etc. can be removed more efficiently.

{0012}

In the above aspects, the housing may have a suction path through which the propagation material retained in the

reservoir chamber is suctioned and drained.

With this configuration, the fatty tissue detached from the organ, etc. by radiating the ultrasonic wave thereto can be suctioned and drained away via the suction path together β

with the propagation material. Consequently, the fatty tissue detached from the organ, etc. can be readily removed from inside the patient's body.

{0013}

In the above aspects, the feed tube may have a narrow ejection port through which the propagation material is ejected into the reservoir chamber.

With this configuration, when the propagation material is fed to the reservoir chamber via the feed tube, the

propagation material spreads over a wide area in the reservoir chamber from the narrow ejection port, whereby a bubble nucleus can be readily formed in the propagation material. In the case where a bubble nucleus is contained in the

propagation material in advance, the bubble nucleus can be further increased in size so as to facilitate cavitation. On the other hand, if the propagation material does not contain a bubble nucleus, like degassed water, a bubble nucleus can be formed therein so as to facilitate cavitation.

{0014 }

In the above aspects, the feed tube may be formed such that a puncture needle having a sharp pointed end is

insertable thereto and removable therefrom.

With this configuration, before the propagation material is fed to the housing from the feed tube, the puncture needle may be inserted into the feed tube so as to puncture and rupture the epicardium, etc. on the surface of the fatty tissue. Thus, a hole for removing the fatty tissue can be formed in the epicardium by using the puncture needle, thereby eliminating the need for performing ultrasonic wave radiation necessary for causing cavitation for forming a hole in the epicardium.

{0015}

In the above aspects, the opening may be disposed such that a plane thereof is tilted relative to a center line of the housing.

With this configuration, the opening is pressed onto the surface of the fatty tissue in a state where the housing is tilted relative thereto. This makes it easy to approach the surface of the fatty tissue even in a small space where the distance from the surface of the fatty tissue is short. For example, in an extracardiac approach, the distance to the pericardium is reduced, thereby reducing the risk of cardiac tamponade .

{0016}

In the above aspects, the fat removal device may further include a tubular member that covers the housing while

exposing the opening. In this case, the tubular member may include a suction tube disposed between the tubular member and the housing, and a hole that is attachable by suction to the surface of the fatty tissue in a state where the opening is pressed onto the surface of the fatty tissue.

With this configuration, the tubular member is attached to the surface of the fatty tissue by suction via the hole in the state where the opening of the housing is pressed onto the surface of the fatty tissue. In this case, even if the propagation material fed to the reservoir chamber in the housing leaks outward from the housing via the opening, the leakage of the propagation material can be stopped by the tubular member, and the propagation material can be collected by the suction tube. This reliably prevents the propagation material from remaining in the body of the living organism. {0017}

In the above aspects, the fat removal device may further include a push-pull mechanism that moves the ultrasonic element toward and away from the opening.

With this configuration, the ultrasonic element is moved back and forth by the push-pull mechanism so that the focal point of the ultrasonic wave can be moved in the thickness direction of the fatty tissue. Thus, the fatty tissue can be excavated and removed in the thickness direction thereof until reaching near the surface of the organ, etc. to which the fatty tissue is adhered.

{0018}

In the above aspects, the fat removal device may further include a distance calculator that calculates the distance between the ultrasonic element and the surface of the fatty tissue exposed within the housing through the opening, and a controller that controls a push-pull mechanism in accordance with the distance calculated by the distance calculator.

With this configuration, based on the distance between the surface of the fatty tissue and the ultrasonic element calculated by the distance calculator, the controller

feedback-controls the push-pull mechanism so that the fatty tissue can be automatically removed in the thickness direction thereof .

{Advantageous Effects of Invention}

{0019}

The present invention is advantageous in that it can remove fatty tissue while preventing heat from being

transferred to surrounding tissue.

{Brief Description of Drawings}

{0020}

{Fig. 1A} Fig. 1A is a longitudinal sectional view of a fat removal device according to a first embodiment of the present invention, taken in the longitudinal direction thereof.

{Fig. IB} Fig. IB is a cross-sectional view of the fat removal device in Fig. 1A.

{Fig. 2A} Fig. 2A is a longitudinal sectional view of a fat removal device according to a first modification of the first embodiment of the present invention. {Fig. 2B} Fig. 2B is a cross-sectional view of the fat removal device in Fig. 2A.

{Fig. 3} Fig. 3 is an external view illustrating a state where a feed pump and a drain pump are connected to the fat removal device in Figs. 2A and 2B.

{Fig. 4} Fig. 4 is a longitudinal sectional view of a fat removal device according to a second modification of the first embodiment of the present invention.

{Fig. 5} Fig. 5 is a longitudinal sectional view of a fat removal device according to a third modification of the first embodiment of the present invention.

{Fig. 6} Fig. 6 is a longitudinal sectional view of a fat removal device according to a fourth modification of the first embodiment of the present invention.

{Fig. 7A} Fig. 7A is an external view of a fat removal device according to a fifth modification of the first embodiment of the present invention.

{Fig. 7B} Fig. 7B is a longitudinal sectional view of the fat removal device in Fig. 7A.

{Fig. 8} Fig. 8 is a longitudinal sectional view of a fat removal device according to a sixth modification of the first embodiment of the present invention.

{Fig. 9A} Fig. 9A illustrates a state where the epicardium, etc. is ruptured by the fat removal device in Fig. 8.

{Fig. 9B} Fig. 9B illustrates a state where a propagation material is fed to a reservoir chamber after the epicardium is ruptured.

{Fig. 10} Fig. 10 is a longitudinal sectional view of a fat removal device according to a seventh modification of the first embodiment of the present invention.

{Fig. 11} Fig. 11 is a longitudinal sectional view of a fat removal device according to an eighth modification of the first embodiment of the present invention.

{Fig. 12A} Fig. 12A illustrates a state where ultrasonic waves are focused on the surface of fatty tissue by the fat removal device in Fig. 11.

{Fig. 12B} Fig. 12B illustrates a state where a hole is formed in the fatty tissue.

{Fig. 12C} Fig. 12C illustrates a state where the hole in Fig. 12B is made deeper.

{Fig. 13} Fig. 13 illustrates a configuration for

automatically controlling a push-pull mechanism of the fat removal device in Fig. 11.

{Fig. 14} Fig. 14 is a longitudinal sectional view of a fat removal device according to a second embodiment of the present invention, taken in the longitudinal direction thereof.

{Description of Embodiments}

{0021}

{First Embodiment}

A fat removal device according to a first embodiment of the present invention will be described below with reference to the drawings.

The fat removal device according to this embodiment is capable of dissolving fatty tissue adhered to an organ, such as the heart, of a living organism. For example, as shown in Fig. 1A, a fat removal device 100 includes a hollow,

substantially-cylindrical, narrow housing 10 that is to be inserted into a living organism; an ultrasonic element 20 that is accommodated in the housing 10 and generates focused ultrasonic waves; and a feed tube 30 that feeds a propagation material W, through which the ultrasonic waves propagate, into the housing 10.

{0022}

The housing 10 has an opening 10a located on the center line of a distal end thereof. By pressing the opening 10a onto fatty tissue A, the surface of the fatty tissue A can be exposed within the housing 10 through the opening 10a.

Furthermore, the housing 10 has a reservoir chamber 12 between the ultrasonic element 20 and the surface of the fatty tissue A exposed within the housing 10 through the opening 10a, such that the propagation material W can be retained therein. The propagation material W is, for example, a liquid having fluidity, such as a non-degassed physiological saline

solution .

{0023} As shown in Figs. 1A and IB, the ultrasonic element 20 has the shape of a ring with a through-hole 20a in the center and has a surface that is recessed in the thickness direction. The ultrasonic element 20 is engaged with and supported by a distal end of a tubular element holder 22 having an outer diameter that is slightly smaller than the inner diameter of the housing 10. The ultrasonic element 20 is disposed such that the surface thereof faces the opening 10a. Moreover, the ultrasonic element 20 is positioned so that the focal point of the focused ultrasonic waves substantially coincides with the opening 10a of the housing 10. Reference character P denotes the focal point of the ultrasonic waves.

{0024}

The ultrasonic element 20 generates focused ultrasonic waves (with a center frequency of, for example, 1 MHz) and radiates the ultrasonic waves onto the surface of the fatty tissue A exposed in the reservoir chamber 12 through the opening 10a. The reverse surface of the ultrasonic element 20 is in contact with the air, and watertightness is maintained by the element holder 22. With the ultrasonic element 20 accommodated within the housing 10, the ultrasonic element 20 can be prevented from directly coming into contact with the living organism, thereby ensuring electrical safety. In particular, electrical safety can be ensured when performing medical treatment on the heart. {0025}

The feed tube 30 is disposed so as -to be insertable into and removable from the through-hole 20a in the ultrasonic element 20. The feed tube 30 has an ejection port 30a from which the propagation material W is ejected. The ejection port 30a is flush with the surface of the ultrasonic element 20. In the state where the surface of the fatty tissue A is exposed in the reservoir chamber 12 through the opening 10a of the housing 10, the feed tube 30 feeds the propagation

material W to the reservoir chamber 12 so as to fill it with the propagation material W, whereby a ultrasonic-wave

propagation space is formed by the propagation material W between the surface of the fatty tissue A and the ultrasonic element 20.

{0026}

Next, the operation of the fat removal device 100 having the above-described configuration will be described below.

In order to remove the fatty tissue A adhered to an organ, etc. of a living organism by using the fat removal device 100 according to this embodiment, the housing 10 is first inserted into the living organism so as to press the opening 10a of the housing 10 onto the fatty tissue A

(pressing step) . Thus, the opening 10a of the housing 10 is blocked by the fatty tissue A, and the surface of the fatty tissue A becomes exposed in the reservoir chamber 12 of the housing 10.

{0027}

Subsequently, the feed tube 30 feeds the propagation material W into the reservoir chamber 12 so that the

propagation material W fills the reservoir chamber 12 (feeding step) . When the reservoir chamber 12 is filled with the propagation material W, the ultrasonic element 20 generates 1- MHz high-intensity ultrasonic waves that are focused toward the opening 10a of the housing 10 and radiates the ultrasonic waves onto the surface of the fatty tissue A exposed in the reservoir chamber 12 via the propagation material W (radiating step) .

{0028}

When the ultrasonic waves are radiated to the focal point on the surface of the fatty tissue A, negative pressure is generated in an area on the surface of the fatty tissue A that coincides with the focal point P of the ultrasonic waves so that a bubble nucleus contained in the propagation material W grows, thus causing cavitation. Thus, the fatty tissue A irradiated with the ultrasonic waves becomes dissolved or fragmented so as to become detached from the organ, etc.

{0029}

In this case, acoustic streaming occurs in the

propagation material W due to the nonlinear properties of the ultrasonic waves. The acoustic streaming flows in the radiation direction of the ultrasonic waves, and the sonic speed thereof reaches a maximum when the sound pressure of the ultrasonic waves is at the highest level, that is, at the focal point P of the ultrasonic waves. Therefore, the fatty tissue A detached from the organ, etc. due to the cavitation occurring at the surface of the fatty tissue A can be washed away by the acoustic streaming. Moreover, the area from which the fatty tissue A is detached can be cooled by a water- cooling effect of the acoustic streaming.

{0030}

As described above, with the fat removal device 100 according to this embodiment, the ultrasonic element 20 radiates the ultrasonic waves onto the surface of the fatty tissue A exposed within the housing 10 through the opening 10a thereof so that cavitation occurs, thereby detaching the fatty tissue A from the organ, etc. Moreover, the detached fatty tissue A is washed away by the acoustic streaming of the propagation material W, and at the same time, the area from which the fatty tissue A is detached can be cooled by the cooling effect thereof. Consequently, the fatty tissue A can be removed while preventing the heat generated by the

ultrasonic waves from being transferred to surrounding tissue. {0031}

The above embodiment may be modified as follows.

Referring to Figs. 2A and 2B, as a first modification, for example, the housing 10 may have a suction path 14 through which the propagation material W retained in the reservoir chamber 12 can be suctioned and drained away. In this case, a gap may be provided between the inner wall of the housing 10 and the outer wall of the element holder 22 so that the gap can function as the suction path 14. Furthermore, as shown in Fig. 3, the feed tube 30 may be connected to a feed pump 31, and the suction path 14 may be connected to a drain pump 15. In this case, the propagation material W sent from the feed pump 31 may be fed to the reservoir chamber 12 via the feed tube 30, whereas the propagation material in the reservoir chamber 12 may be suctioned and drained by the drain pump 15 via the suction path 14. In the state where the reservoir chamber 12 is filled with the propagation material W, the ultrasonic waves may be radiated onto the surface of the fatty tissue A.

{0032}

Accordingly, the fatty tissue A detached from the organ, etc. due to being irradiated with the ultrasonic waves and washed away by the acoustic streaming can be suctioned and drained away (suctioning step) together with the propagation material W via the suction path 14. Thus, the fatty tissue A detached from the organ, etc. can be readily removed from inside the patient's body.

In the following modifications and embodiments, the housing 10 will be described as having the suction path 14. Furthermore, in second to fifth modifications, seventh and eighth modifications, and a second embodiment to be described below, the feed pump 31 and the drain pump 15 shown in Fig. 3 may respectively be connected to the feed tube 30 and the suction path 14.

{0033}

Referring to Fig. 4, as a second modification, for example, the ejection port 30a of the feed tube 30 may have a small diameter so that the propagation material W can be readily ejected into the reservoir chamber 12 with high momentum. In this case, the distal end of the feed tube 30 may be tapered such that only the distal end of the feed tube 30 to be inserted into the through-hole 20a in the ultrasonic element 20 is locally reduced in diameter.

{0034}

Accordingly, when the propagation material W is fed to the reservoir chamber 12 via the feed tube 30, the propagation material W spreads with high momentum over a wide area in the reservoir chamber 12 from the narrow ejection port 30a, whereby a bubble nucleus can be readily formed in the

propagation material . In the case where a bubble nucleus is contained in the propagation material W in advance, the bubble nucleus can be further increased in size so as to facilitate cavitation. On the other hand, if the propagation material W does not contain a bubble nucleus, like degassed water, a bubble nucleus can be formed therein so as to facilitate cavitation .

{0035}

Referring to Fig. 5, as a third modification, instead of disposing the ejection port 30a of the feed tube 30 flush with the surface of the ultrasonic element 20, the distal end of the feed tube 30 may protrude from the surface of the

ultrasonic element 20 toward the opening 10a of the housing 10 so that the ejection port 30a is disposed near the opening 10a.

{0036}

Accordingly, the distance from the surface of the fatty tissue A exposed through the opening 10a to the ejection port 30a of the feed tube 30 is reduced, thereby increasing the acoustic streaming effect of the propagation material W, as well as increasing the flow rate of circulating current near the focal point P of the ultrasonic waves.

{0037}

Referring to Fig. 6, as a fourth modification, the ultrasonic element 20 may be disk-shaped, and the ejection port 30a of the feed tube 30 may be disposed radially outward of the ultrasonic element 20. In this case, a plurality of feed tubes 30 may be arranged and spaced apart from each other in the circumferential direction around the element holder 22,

I and the propagation material W may be ejected from the ejection ports 30a of the feed tubes 30 parallel to the radiation direction of the ultrasonic waves emitted from the ultrasonic element 20. This allows for an increased acoustic streaming effect of the propagation material W, as well as an increased flow rate of circulating current near the focal point P of the ultrasonic waves.

{0038 }

Referring to Figs. 7A and 7B, as a fifth modification, instead of disposing the opening 10a such that the plane thereof is orthogonal to the center line of the housing 10, the plane of the opening 10a may be tilted relative to the center line of the housing 10. In this case, the opening 10a may be disposed such that an angle formed between the center line of the housing 10 and the plane of the opening 10a is an acute angle. Furthermore, the position of the ultrasonic element 20 may be adjusted in accordance with the position and the orientation of the opening 10a so that the focal point P of the ultrasonic waves coincides with the opening 10a.

{0039}

Accordingly, the opening 10a is pressed onto the surface of the fatty tissue A in a state where the housing 10 is tilted relative thereto. This makes it easy to approach the surface of the fatty tissue A even in a small space where the distance from the surface of the fatty tissue A is short. For example, in an extracardiac approach, the distance to the pericardium is reduced, thereby reducing the risk of cardiac tamponade .

{0040}

Referring to Fig. 8, as a sixth modification, the feed tube 30 may function as, for example, a sheath into and from which a puncture needle 32 having a sharp pointed end 32a can be inserted and removed. In this case, for example, the base end of the feed tube 30 may be divided into two branch paths, such that one branch path may be connected to a pump, etc. to which the propagation material W is delivered, whereas the other branch path may accommodate the puncture needle 32 therein in a movable manner.

{0041}

In this case, as shown in Fig. 9A, before the propagation material W is fed to the reservoir chamber 12 from the feed tube 30, the puncture needle 32 is inserted into the feed tube 30 so as to puncture and rupture the epicardium B, etc. on the surface of the fatty tissue A (puncturing step) . Then, as shown in Fig. 9B, the puncture needle 32 is withdrawn into the feed tube 30, and the propagation material is fed to the reservoir chamber 12 from the feed tube 30. Accordingly, a hole for removing the fatty tissue A can be formed in the epicardium B by using the puncture needle 32, thereby

eliminating · the need for performing ultrasonic wave radiation necessary for causing cavitation for forming a hole in the epicardium B.

{0042}

Referring to Fig. 10, as a seventh modification, a tubular member 40 having a larger diameter than the housing 10 may be used to cover a radially-outward area of the housing 10 while leaving the opening 10a of the housing 10 exposed. In this case, the tubular member 40 may include suction tubes 42 disposed in a gap between the tubular member 40 and the outer wall surface of the housing 10, and a hole 40a that is

attachable by suction to the surface of the fatty tissue A in a state where the opening 10a is pressed onto the surface of the fatty tissue A. In Fig. 10, multiple suction tubes 42 are arranged and spaced apart from each other in the suction path 14 and in an area surrounding the housing 10.

{0043}

Because the hole 40a of the tubular member 40 is attached to the surface of the fatty tissue A by suction, even if the propagation material fed to the reservoir chamber 12 in the housing 10 leaks outward from the housing 10 via the opening 10a, the leakage of the propagation material W can be stopped by the tubular member 40, and the propagation material W can be collected by the suction tubes 42. This reliably prevents the propagation material from remaining in the body of the living organism. { 0044 }

Referring to Fig. 11, as an eighth modification, a push- pull mechanism 50 that can move the ultrasonic element 20 toward and away from the opening 10a of the housing 10 may be provided. In this case, the push-pull mechanism 50 may be disposed at the base end of the element holder 22 so that the base end of the element holder 22 may be pushed or pulled by the push-pull mechanism 50, thereby moving the ultrasonic element 20 back and forth together with the element holder 22. The push-pull mechanism 50 may be of any kind so long as it is compact, and may be, for example, a shape-memory alloy

component or a piezoelectric element that is expandable and contractible along the center line of the housing 10.

{0045}

By means of the ultrasonic element 20 moved back and forth by the push-pull mechanism 50, the focal point P of the ultrasonic waves can be moved in the thickness direction of the fatty tissue A. Thus, the fatty tissue A can be excavated and removed in the thickness direction thereof until reaching near the surface of the organ, etc. to which the fatty tissue A is adhered.

{0046}

For example, as shown in Fig. 12A, when commencing medical treatment for dissolving the fatty tissue A,

positional adjustment is performed so that the focal point of the ultrasonic waves substantially coincides with the opening 10a of- the housing 10 (namely, the surface of the fatty tissue A) . When the ultrasonic waves are radiated onto the surface of the fatty tissue A in this state, the surface of the fatty tissue A near the focal point P becomes dissolved and is physically removed, thereby forming a hole C in the fatty tissue A. Subsequently, as shown in Fig. 12B, the push-pull mechanism 50 moves the element holder 22 forward so that the focal point P substantially coincides with the bottom of the hole C formed in the fatty tissue A. Then, the ultrasonic waves are radiated again so as to make the hole C deeper.

{0047}

By repeating these steps, a narrow hole C that extends deep into an area near the cardiac muscle is formed, as shown in Fig. 12C. This series of steps may be performed by

manually operating the push-pull mechanism 50 or by

automatically controlling the push-pull mechanism 50.

Moreover, in order to perform this series of steps

continuously, the element holder 22 may be moved forward continuously by the push-pull mechanism 50.

{0048 }

If the push-pull mechanism 50 is to be automatically controlled, the following configuration is possible. For example, as shown in Fig. 13, a transmitter-receiver circuit 52 that generates a pulse signal, a transmitter-receiver converter 54 that transmits and receives the pulse signal, a distance calculator 56 that calculates the distance between- the surface of the fatty tissue A exposed in the reservoir chamber 12 through the opening 10a and the ultrasonic element 20, and a controller 58 that controls the push-pull mechanism 50 in accordance with the distance calculated by the distance calculator 56 may be provided.

{0049}

In this case, the transmitter-receiver converter 54 may be provided in an insertable-removable manner in the feed tube 30 and may be disposed such that a detection surface of the transmitter-receiver converter 54 inserted in the feed tube 30 is substantially aligned with the surface of the ultrasonic element 20. The distance calculator 56 may calculate a difference (i.e., a time difference) between the transmission time point of a sound wave and the first reception time point of the sound wave on the basis of a pulse signal of a

reflected wave detected by the transmitter-receiver converter 54 and transmitted from the transmitter-receiver circuit 52, so as to determine the distance from the sound source to the surface of the fatty tissue A.

{0050}

Accordingly, based on the distance between the surface of the fatty tissue A and the ultrasonic element 20 calculated by the distance calculator 56, the controller 58 feedback- controls the push-pull mechanism 50 so that the fatty tissue A can be automatically removed in the thickness direction thereof.

{0051}

In addition to controlling the push-pull mechanism 50, the controller 58 may stop the radiation of the ultrasonic waves for dissolving the fatty tissue A in accordance with a reflected wave response. For example, when monitoring a removal process of the fatty tissue A on a cardiac surface, if the time difference between a first reflected wave and a second reflected wave is small, the fat removal at the outer side of the cardiac muscle is substantially completed, meaning that the surface of the cardiac muscle will shortly become exposed. Therefore, a time difference ΔΤ between the first reflected wave and the second reflected wave may be set in advance and used as a threshold value so that when a time difference At during monitoring becomes smaller than or equal to ΔΤ, the ultrasonic element 20 may be controlled so as to stop the radiation of ultrasonic waves.

{0052}

{Second Embodiment}

Next, a fat removal device 200 according to a second embodiment of the present invention will be described with reference to Fig. 14.

The fat removal device 200 according to this embodiment differs from that in the first embodiment in that the housing 10 includes a film (partition member) 60 that partitions the housing 10 into an opening region 62A filled with the

propagation material W fed from the feed tube 30 and an ultrasonic-element region 62B filled with the propagation material W in advance.

In the following description, components that are the same as those in the fat removal device 100 according to the first embodiment are given the same reference numerals, and descriptions thereof will be omitted.

{0053}

The element holder 22 protrudes toward the opening 10a of the housing 10 from the front surface of the ultrasonic element 20 and positionally fixes the ultrasonic element 20 at an intermediate position in the longitudinal direction.

Similar to the element holder 22, the feed tube 30 extends toward the opening 10a of the housing 10 from the front surface of the ultrasonic element 20.

{0054}

The film 60 is composed of a resinous material with high acoustic transmission characteristics, such as polyethylene terepht'halate (PET) or polycarbonate, and is formed thin enough to ensure sufficient thin-film strength. Preferably, the film 60 is sufficiently thin relative to (for example, smaller than or equal to about 1/10 of) the wavelength of the sound waves.

{0055}

The film 60 is ring-shaped and is disposed at the distal end of the element holder 22 so as to surround the ejection port 30a of the feed tube 30. Thus, the element holder 22, the ultrasonic element 20, and the film 60 form the

ultrasonic-element region 62B, which is a sealed chamber, around the feed tube 30. Furthermore, the opening region 62A into which the ejection port 30a of the feed tube 30 opens is formed around the ultrasonic-element region 62B and is

surrounded by the housing 10 and the surface of the fatty tissue A exposed therein through the opening 10a.

The propagation material that fills the ultrasonic- element region 62B in advance may be a material that satisfies acoustic matching conditions with the ultrasonic element 20 or a liquid with a small absorption coefficient, such as water. {0056}

With the fat removal device 200 according to this

embodiment having the above-described configuration, the ultrasonic element 20 is double-insulated by the housing 10 and the film 60 from the surface of the fatty tissue A that is to be disposed adjacent to the opening 10a of the housing 10, thereby allowing for improved electrical safety. Furthermore, the space within the housing 10 filled with the propagation material W fed from the feed tube 30 can be reduced, due to the ultrasonic-element region 62B, as compared with a case where the entire region from the surface of the fatty tissue A to the ultrasonic element 20 is used. Thus, the floating period of a bubble nucleus contained in the propagation material W fed from the feed tube 30 is reduced, thereby allowing for improved cavitation generation efficiency.

Furthermore, the propagation material can be made to circulate readily, so that the fatty tissue A detached from the organ, etc. can be removed more efficiently.

{0057}

Although the embodiments of the present invention have been described in detail above with reference to the drawings, specific configurations are not limited to these embodiments, and design modifications and the like are included so long as they do not depart from the spirit of the invention. For example, the present invention is not limited to the above embodiments and the modifications thereof and may be applied to an embodiment with an appropriate combination of these embodiments and modifications; the invention is not limited in particular. Furthermore, for example, although the ultrasonic element 20 is configured to radiate ultrasonic waves with a center frequency of 1 MHz in the above embodiments, the center frequency of the ultrasonic element 20 may range between about several tens of kHz and several MHz and is not limited to the numeral value described in the above embodiments. The frequency may be set to a low value of several tens of kHz if the cavitation effect is to be increased, or may be set to a high value if the acoustic streaming effect is to be

increased.

{0058}

Moreover, a combination of ultrasonic waves with

different frequencies may be radiated. For example, 1-MHz ultrasonic waves and 1.5-MHz ultrasonic waves may be radiated. In this case, utilizing the effective generation of a

difference tone of 500 kHz and a harmonic tone of 2.5 MHz at the focal point may facilitate the occurrence of cavitation by the difference-tone component and the occurrence of acoustic streaming by the harmonic tone. The combination of different frequencies may be set in accordance with the size of the bubble nucleus contained in the injected liquid (i.e., the propagation material) , that is, the resonance frequency of the bubble nucleus.

{0059}

{Additional Item 1}

A fat removal method including a pressing step for pressing an opening of a housing onto a surface of fatty tissue; a feeding step for filling a space between an

ultrasonic element and the surface of the fatty tissue exposed within the housing through the opening in the pressing step with a fluidic propagation material through which an ultrasonic wave propagates; and a radiating step for radiating the ultrasonic wave focused by the ultrasonic element onto the surface of the fatty tissue exposed within the space filled with the propagation material.

{0060}

{Additional Item 2}

The fat removal method according to additional item 1, further including a puncturing step for puncturing and

rupturing an epicardium, which covers the fatty tissue pressed in the pressing step, by using a puncture needle.

{0061}

{Additional Item 3}

The fat removal method according to additional item 1 or 2, further including a suctioning step for suctioning and draining the fatty tissue dissolved by heat generated by the ultrasonic wave radiated in the radiating step.

{Reference Signs List}

{0062}

A fatty tissue

10 housing

10a opening

12 reservoir chamber

14 suction path

20 ultrasonic element

20a through-hole feed tube

a ejection port

puncture needle

a pointed end

tubular member

a hole

suction tube

push-pull mechanism distance calculator controller

film (partition member)A opening region

B ultrasonic-element region0, 200 fat removal device

Claims

{ CLAIMS }

{Claim 1}

A fat removal device comprising:

a substantially tubular housing having an opening that is pressed onto fatty tissue;

an ultrasonic element that is accommodated in the housing and radiates a focused ultrasonic wave onto a surface of the fatty tissue exposed within the housing due to being pressed by the opening; and

a feed tube that feeds a fluidic propagation material, through which the ultrasonic wave propagates, into the

housing,

wherein the housing has a reservoir chamber that is located between the ultrasonic element and the surface of the fatty tissue exposed within the housing through the opening and that is filled with the propagation material fed from the feed tube.

{Claim 2}

A fat removal device comprising:

an ultrasonic element that is accommodated in the housing and radiates a focused ultrasonic wave onto a surface of the fatty tissue exposed within the housing due to being pressed by the opening; and a feed tube that feeds a fluidic propagation material into the housing,

wherein the housing includes a partition member that has acoustic transmission characteristics and partitions the housing into an opening region filled with the propagation material fed from the feed tube and a ultrasonic-element region filled with the propagation material in advance.

{Claim 3}

The fat removal device according to Claim 1 or 2, wherein the housing has a suction path through which the propagation material retained in the reservoir chamber is suctioned and drained.

{Claim 4}

The fat removal device according to Claim 1 or 3, wherein the feed tube has a narrow ejection port through which the propagation material is ejected into the reservoir chamber. {Claim 5}

The fat removal device according to any one of Claims 1 to 4, wherein the feed tube is formed such that a puncture needle having a sharp pointed end is insertable thereto and removable therefrom.

{Claim 6}

The fat removal device according to any one of Claims 1 to 5, wherein the opening is disposed such that a plane thereof is tilted relative to a center line of the housing. {Claim 7}

The fat removal device according to any one of Claims 1 to 6, further comprising a tubular member that covers the housing while exposing the opening,

wherein the tubular member includes a suction tube disposed between the tubular member and the housing, and a hole that is attachable by suction to the surface of the fatty tissue in a state where the opening is pressed onto the surface of the fatty tissue.

{Claim 8}

The fat removal device according to any one of Claims 1 to 7, further comprising a push-pull mechanism that moves the ultrasonic element toward and away from the opening.

{Claim 9}

The fat removal device according to Claim 1, further comprising :

a distance calculator that calculates the distance between the ultrasonic element and the surface of the fatty tissue exposed within the housing through the opening; and

a controller that controls the push-pull mechanism in accordance with the distance calculated by the distance calculator .