The present invention generally relates to a blood vessel insertion-type treatment device. More specifically, the invention pertains to a blood vessel insertion-type treatment device which is configured to be inserted into a blood vessel to perform cauterization on biological tissues around the blood vessel through the inside of the blood vessel.
In recent years, it is understood that abnormal renal artery sympathetic nerve activity causes congestive heart failure, renal failure, hypertension, and other cardio-renal diseases. In addition, it is also known that these diseases are treated by removing a renal artery sympathetic nerve. In order to perform cauterization on the renal artery sympathetic nerve, a renal neuromodulation apparatus has been proposed which inserts an electrode into a renal artery and applies a pulse output electric field to the renal artery exchange nerve from the electrode. An example of this apparatus is disclosed in Japanese Application Publication No. 2008-515544.
In the cauterization of the renal artery sympathetic nerve which is performed by the renal neuromodulation apparatus disclosed in Japanese Application Publication No. 2008-515544 using the pulse output electric field, current density in a blood vessel intima increases to the maximum. For this reason, heat generated in the blood vessel intima increases to the maximum. Therefore, there is a possibility that the cauterization is performed on the entire vessel wall including the blood vessel intima. Consequently, side effects such as intimal thickening and thrombosis may occur.
A blood vessel insertion-type treatment device is disclosed which is configured to cauterize biological tissue around a blood vessel, such as the sympathetic nerve around a renal artery, while also suppressing damage to the blood vessel.
According to one aspect, a blood vessel insertion-type treatment device comprises: an elongated insertion body possessing an insertion end configured to be inserted into a blood vessel and a proximal end; and an ultrasonic generator axially movably positioned in the insertion body. The ultrasonic generator includes an ultrasonic transducer which radiates cauterizing ultrasonic waves converging on a converging position and an actuator which adjusts the ultrasonic transducer to change a location of the converging position at which converge the cauterizing ultrasonic waves radiated by the ultrasonic transducer.
The cauterizing ultrasonic waves converging on the converging position cauterize biological tissue on the converging position. Therefore, it is possible to suppress damage to blood vessels interposed between the ultrasonic generator and cauterizing target tissues. In addition, the actuator changes the direction from the ultrasonic transducer to the converging position. Therefore, without being limited to one specific point, it is possible to cauterize the biological tissue around the blood vessel even while an ultrasonic generator is used.
According to another aspect, a blood vessel insertion-type treatment device includes a sheath configured to be inserted into and moved along a blood vessel, wherein the sheath possesses an open distal end, an elongated insertion body positioned in the sheath and axially movable relative to the sheath to project a distal end portion of the elongated insertion body distally beyond the open distal end of the sheath, an ultrasonic transducer which radiates cauterizing ultrasonic waves that converge, wherein the ultrasonic transducer is located at the distal end portion of the elongated insertion body, and an actuator on which the ultrasonic transducer is mounted so that the ultrasonic transducer overlies the actuator and which is operable to adjust a location at which the cauterizing ultrasonic waves radiated by the ultrasonic transducer converge. The actuator is disposed on the elongated insertion body so that the actuator and the elongated insertion body move together as a unit.
In accordance with another aspect, a method of treating a treatment location comprises: inserting an elongated body into a blood vessel, with an ultrasonic transducer which radiates cauterizing ultrasonic waves that converge being located at a distal end portion of the elongated insertion body and being movable together with the elongated body as a unit; moving the elongated body along the blood vessel to position the distal end portion of the elongated body adjacent the treatment location; adjusting tilt of the ultrasonic transducer to change a converging position at which the cauterizing ultrasonic waves radiated by the ultrasonic transducer converge so that the converging position is at the treatment location; and radiating cauterizing ultrasonic waves at the treatment location to cauterize the treatment location.
Hereinafter, embodiments of a blood vessel insertion-type treatment device representing examples of the blood vessel insertion-type treatment device disclosed here will be described with reference to the drawings.
Referring to
The guiding catheter 200 has a tubular shape, and medical examination and treatment devices can be inserted into the guiding catheter 200. A blood vessel insertion-type treatment device 100 possesses an overall elongated shape, has an insertion end and a proximal end, and is insertable into a lumen of the guiding catheter 200 through the insertion end. The surgeon inserts the blood vessel insertion-type treatment device 100 into the guiding catheter 200, and causes the insertion end to protrude from the guiding catheter 200 (refer to
As described below, the blood vessel insertion-type treatment device 100 has an imaging function and a cauterizing function. To fulfill the imaging function, the blood vessel insertion-type treatment device 100 is configured to radiate imaging ultrasonic waves (IUS in
Based on the acquired image, the surgeon determines a sympathetic nerve SN to be cauterized, and adjusts the position of the blood vessel insertion-type treatment device 100 so that cauterizing ultrasonic waves are radiated to the determined sympathetic nerve SN. The cauterizing ultrasonic waves are identified as CUS in
Next, a configuration of the blood vessel insertion-type treatment device 100 will be described with reference to
The sheath 102 possesses a tubular shape and is a member having acoustic characteristics and flexibility. A distal end portion on the insertion end side of the sheath 102 is open. In addition, when the sheath 102 starts to be used, the sheath 102 is internally filled, from the proximal end, with a medium having acoustic transmission characteristics or properties. A tongue piece (not illustrated) extending to an inner surface is formed on the proximal side of the sheath 102.
The insertion body 103 is a flexible member extending from the proximal end of the sheath 102 to the insertion end (distal end) of the sheath 102. In a state where the insertion end or distal end of the insertion body 103 is positioned at the insertion end or distal end of the sheath 102, the proximal end of the insertion body 103 protrudes from the proximal end of the sheath 102. The insertion body 103 is thus longer than the sheath 102.
The outer diameter of the insertion body 103 is narrower (smaller) than the inner diameter of the sheath 102, and the insertion body 103 is freely displaceable or axially movable inside the sheath 102 in the longitudinal direction. A longitudinally extending groove portion (groove) D is formed in the insertion body 103. The tongue piece of the sheath 102 engages (is positioned in) the groove portion D to prevent pivotal rotation of the insertion body 103 inside the sheath 102 about the longitudinal direction.
The first ultrasonic generator 104 is disposed near the insertion end or distal end of the insertion body 103. The first ultrasonic generator 104 is axially spaced from the image acquisition unit 105 along the longitudinal or axial extent of the insertion body 103. A recessed portion (recess) is formed near the insertion end of the insertion body 103, and the first ultrasonic generator 104 is embedded or positioned in the recessed portion. The first ultrasonic generator 104 has a single unit of a first ultrasonic transducer 106 (the first ultrasonic transducer 106 in this embodiment consists of a single ultrasonic transducer), an acoustic lens 107, and a first actuator 108.
The first ultrasonic transducer 106 possesses a flat plate shape, and radiates cauterizing ultrasonic waves CUS, having a frequency suitable for cauterization, from a plate surface. Depending on the frequency, a distance for transmitting the ultrasonic waves and a calorific value in a converging position of the ultrasonic waves are determined. Therefore, the frequency of the cauterizing ultrasonic waves CUS is predetermined, based on an approximate interval from the inside of the renal artery RA to the renal artery sympathetic nerve SN and the calorific value required for the cauterization of the sympathetic nerve SN.
A signal line, extending from the first ultrasonic transducer 106 to the proximal end of the insertion body 103, is connected to a cauterization control unit. The cauterization control unit supplies a drive signal to the first ultrasonic transducer 106 to generate the cauterizing ultrasonic waves CUS at the above-described frequency.
The acoustic lens 107 is disposed on a surface of the first ultrasonic transducer 106. The acoustic lens 107 causes the ultrasonic waves to converge at the converging position away from the acoustic lens 107 by a predetermined distance, thereby maximizing heat energy near the converging position. The acoustic lens 107 is configured to have a predetermined focal length, based on the approximate distance from the inside of the renal artery to the renal artery sympathetic nerve.
The first actuator 108 can cause a plate surface of the first ultrasonic transducer 106 on which the acoustic lens 107 is located to tilt from (deviate from) a first reference axis RX1. The first reference axis RX1 is normal (perpendicular) to the plate surface of the first ultrasonic transducer 106 in a state where the first actuator 108 is not driven or not operated.
The first actuator 108 is configured to cause the first ultrasonic transducer 106 to tilt from the first reference axis RX1 in a direction along a first tilting plane (plane of the paper in
A signal line, extending from the first actuator 108 to the proximal end of the insertion body 103, is connected to the cauterization control unit. The cauterization control unit supplies the first actuator 108 with a drive signal for causing the first ultrasonic transducer 106 to tilt along the first tilting plane and the second tilting plane. The first actuator 108 thus tilts or adjusts the position of the first ultrasonic transducer 106 relative to the elongated body 103, and the first actuator 108 performs this adjustment independent of any movement (rotational movement or axial movement) of the elongated body 103.
As illustrated in
The imaging ultrasonic transducer 109 possesses a flat plate shape and generates, from the plate surface, imaging ultrasonic waves IUS suitable for acquisition of an image. In addition, the imaging ultrasonic transducer 109 generates a pixel signal corresponding to the reflected waves of the imaging ultrasonic waves IUS. The resolution of the reflected waves of the ultrasonic waves changes depending on the frequency of the ultrasonic waves. Based on the resolution required for confirmation and medical examination of the position of a specific sympathetic nerve, the frequency of the imaging ultrasonic waves IUS is predetermined.
A signal line, extending from the imaging ultrasonic transducer 109 to the proximal end of the insertion body 103, is connected to an imaging control unit. The imaging control unit supplies the imaging ultrasonic transducer 109 with a drive signal for generating the imaging ultrasonic waves IUS at the above-described frequency. In addition, the imaging control unit receives a pixel signal generated by the imaging ultrasonic transducer 109.
The imaging ultrasonic transducer 109 is configured to create an image of tissue, and can also observe a temperature change when the cauterizing ultrasonic waves are radiated and a status change in a state of the tissue. Reflection of the ultrasonic waves occurs at a boundary where acoustic impedance represented by the product of the density of a medium and sound speed of the medium varies. The acoustic impedance varies in such a manner that the density, the sound speed, or hardness of the tissue varies in response to the heating of the tissues. In this manner, a signal of the ultrasonic waves reflected on the tissues varies, and accordingly, it is possible to diagnose a cauterized state of the tissue.
The second actuator 110 is configured to cause the plate surface of the imaging ultrasonic transducer 109 to tilt from a second reference axis RX2. The second reference axis RX2 is normal (perpendicular) to the plate surface of the imaging ultrasonic transducer 109 in a state where the second actuator 110 is not driven or is not operated. In addition, the second reference axis RX2 is included in the first tilting plane (plane of the paper in
The second actuator 110 is configured to cause the imaging ultrasonic transducer 109 to tilt from the second reference axis RX2 in a direction along the first tilting plane (plane of the paper in
A signal line, extending from the second actuator 110 to the proximal end of the insertion body 103, is connected to the imaging control unit. The image control unit supplies the second actuator 110 with a drive signal for causing the imaging ultrasonic transducer 109 to tilt along the first tilting plane and the third tilting plane.
The imaging control unit estimates multiple locations to which the imaging ultrasonic waves are radiated, based on a drive signal transmitted to the second actuator 110 or information for generating the drive signal. The imaging control unit creates an image, based on an image signal and a position of the estimated radiation locations of the imaging ultrasonic waves.
The expandable member 101 is disposed on the sheath 102. A wire configuring the expandable member 101 is bent outward from the blood vessel insertion-type treatment device 100, and the wire presses against the inner wall of the blood vessel. In this manner, the blood vessel insertion-type treatment device 100 can be fixed in the blood vessel.
According to the blood vessel insertion-type treatment device 100 of the first embodiment having the above-described configuration, it is possible to maximize heat energy at the converging position of the cauterizing ultrasonic waves. It is thus possible to cauterize the biological tissues distributed in a range from the inside of the blood vessel to the outside of the blood vessel, while also suppressing damage to the blood vessel interposed between the biological tissues.
In addition, with the blood vessel insertion-type treatment device 100 of the first embodiment, it is possible to change the facing direction of the converging position from the first ultrasonic transducer 106 using the first actuator 108.
In the cauterization of the biological tissue using the ultrasonic transducer, the ultrasonic waves are caused to converge on a focus (focus region). Consequently, a region where the cauterization is possible is only in the vicinity of the focus. Therefore, in the present embodiment, the first actuator 108 is used to change the direction from the first ultrasonic transducer 106 to the converging position. In this manner, it is possible to cauterize the biological tissue distributed at various positions near the insertion end of the sheath 102.
In addition, according to the blood vessel insertion-type treatment device 100 of the first embodiment, the image acquisition unit 105 is disposed near the first ultrasonic generator 104. Therefore, it is relatively easy to confirm the biological tissue to be cauterized, and to confirm the cauterized state.
In particular, the image acquisition unit 105 uses the second actuator 110 to change the posture of the imaging ultrasonic transducer 109 which radiates the imaging ultrasonic waves. In this manner, it is possible to scan the biological tissue around the blood vessel by using the imaging ultrasonic waves.
In addition, according to the blood vessel insertion-type treatment device 100 of the first embodiment, it is possible to temporarily fix the position of the insertion end of the blood vessel insertion-type treatment device 100 in the blood vessel using the expandable member 101. It is possible to reduce a blur in a reproduced image by fixing the blood vessel insertion-type treatment device 100. In addition, it is possible to reduce a blur occurring at the radiation position of the cauterizing ultrasonic waves CUS. Also, because an expandable member 101 is used, it is possible to ensure the blood flow. Accordingly, it is possible to prevent overheating of an inner wall portion of the blood vessel to which the cauterizing ultrasonic waves CUS are radiated, while the blood vessel insertion-type treatment device 100 is fixed in position in the blood vessel.
Next, a blood vessel insertion-type treatment device according to a second embodiment will be described. The second embodiment differs from the first embodiment in that the image acquisition unit is integrated with the first ultrasonic generator. The following description of the second embodiment focuses primarily on differences between this second embodiment and the first embodiment described above and illustrated in
As illustrated in
A first ultrasonic generator 1040 is disposed near the insertion end or distal end of the insertion body 103. A recessed portion (recess) is positioned near the insertion end of the insertion body 103, and the first ultrasonic generator 1040 is embedded or positioned in the recessed portion. The first ultrasonic generator 1040 has a single unit of the first ultrasonic transducer 106 (the first ultrasonic transducer 106 in this embodiment consists of a single ultrasonic transducer), the acoustic lens 107, the first actuator 108, and an imaging ultrasonic transducer 1090. As shown in
The configuration and function of the first ultrasonic transducer 106, the acoustic lens 107, and the first actuator 108 are the same as those in the first embodiment. Therefore, similar to the first embodiment, it is possible to radiate the cauterizing ultrasonic waves CUS to converge on the converging position away from the first ultrasonic generator 1040 by a predetermined distance. In addition, similar to the first embodiment, the first actuator 108 is configured to tilt the first ultrasonic transducer 106 in the direction along the first tilting plane and the second tilting plane.
In this second embodiment, the imaging ultrasonic transducer 1090 is disposed between the first ultrasonic transducer 106 and the acoustic lens 107. For example, the imaging ultrasonic transducer 1090 is formed of a piezoelectric film sheet, and can generate the imaging ultrasonic waves IUS. In addition, the imaging ultrasonic transducer 1090 generates a pixel signal corresponding to the reflected waves of the imaging ultrasonic waves IUS.
The imaging ultrasonic transducer 1090 together with the first ultrasonic transducer 106 can also tilt in response to the drive or operation of the first actuator 108, in the direction along the first tilting plane and the second tilting plane.
According to the blood vessel insertion-type treatment device 1000 of the second embodiment which has the above-described configuration, it is also possible to maximize heat energy at the converging position of the cauterizing ultrasonic waves. Therefore, whereas it is possible to cauterize the biological tissues distributed in a range from the inside of the blood vessel to the outside of the blood vessel, it is also possible to suppress damage to the blood vessel interposed between the biological tissues.
In addition, according to the blood vessel insertion-type treatment device 1000 of the second embodiment, it is also possible to cauterize the biological tissues distributed at various positions near the insertion end of the sheath 102, by driving or operating the first actuator 108. It is also possible to scan the biological tissues around the blood vessel by using the imaging ultrasonic waves. In addition, according to the blood vessel insertion-type treatment device 1000 of the second embodiment, it is possible to temporarily fix the vicinity of the insertion end of the blood vessel insertion-type treatment device 1000 in the blood vessel using the expandable member 01. In addition, since the expandable member 101 is used, it is possible to ensure the blood flow. Accordingly, it is possible to prevent overheating of the inner wall portion of the blood vessel to which the cauterizing ultrasonic waves CUS are radiated, while the blood vessel insertion-type treatment device 100 is fixed into the blood vessel.
Set forth above is a detailed description of examples of the blood vessel insertion-type treatment device disclosed here. However, it should be noted that those skilled in the art can easily perform various modifications and corrections based on the present disclosure. Therefore, all these modifications and corrections are intended to be included within the scope of the present invention.
For example, the blood vessel insertion-type treatment device 100, 1000 of the first and second embodiments includes the expandable member 101. However, a configuration may be employed in which the blood vessel insertion-type treatment device 100, 1000 is temporarily fixed in the blood vessel using other balloons.
In particular, it is preferable to use a balloon for preventing overheating of the inner wall of the blood vessel. For example, as illustrated in
In addition, for example, as illustrated in
Alternatively, it is preferable to use a perfusion balloon and a cryo-balloon in which the inner wall of the blood vessel can be cooled by a refrigerant. In the cauterization using the ultrasonic waves, it is possible to maximize the heating energy at the focus (focal region/point). However, blood vessel walls including the inner wall of the blood vessel through which the ultrasonic waves are propagated prior to convergence may also be heated by the ultrasonic waves. Therefore, it is possible to further reduce a possibility of damage which may occur on the inner wall of the blood vessel, by using the cooling-type balloon.
In addition, in the first embodiment, the first actuator 108 is configured to cause the first ultrasonic transducer 106 to tilt along both the first tilting plane and the second tilting plane. However, the first actuator 108 may be configured to cause the first ultrasonic transducer 106 to tilt along at least any one tilting plane. In addition, the second actuator 110 is configured to cause the imaging ultrasonic transducer 109 to tilt along both the first tilting plane and the third tilting plane. However, the second actuator 110 may be configured to cause the imaging ultrasonic transducer 109 to tilt along at least any one tilting plane.
The first actuator 108 and the second actuator 110 may be configured to cause the first ultrasonic transducer 106 and the imaging ultrasonic transducer 110 to tilt along only the first tilting plane. According to this configuration, it is also possible to cauterize the biological tissues distributed along the circumferential direction of the blood vessel, and to acquire the image of the biological tissues, by rotating the blood vessel insertion-type treatment device 100 about the longitudinal direction. In addition, according to this configuration, without disposing a tongue piece of the sheath 102 in a groove portion D of the insertion body 103, it is also possible to cauterize the biological tissues distributed along the circumferential direction of the blood vessel, and to acquire the image of the biological tissues, by pivotally rotating the insertion body 103 inside the sheath 102 in the longitudinal direction.
The first actuator 108 and the second actuator 110 may be configured to cause the first ultrasonic transducer 106 and the imaging ultrasonic transducer 110 to be respectively tilted along only the second tilting plane and the third tilting plane. According to this configuration, it is also possible to cauterize the biological tissue distributed along the longitudinal direction of the blood vessel, and to acquire the image of the biological tissue by displacing the insertion body 103 inside the sheath 102 in the longitudinal direction.
In addition, in the first embodiment, the image acquisition unit 105 is configured to acquire the image by using the ultrasonic waves, but may be configured to acquire the image, based on optical information such as TD-OCT and HUD-OCT.
In the second embodiment, the imaging ultrasonic transducer 1090 is configured to be interposed between the first ultrasonic transducer 106 and the acoustic lens 107, but may be configured to be interposed between the first ultrasonic transducer 106 and the first actuator 108.
The detailed description above describes features and aspects of embodiments of a blood vessel insertion-type treatment device and manner of use/operation of a blood vessel insertion-type treatment device. The invention is not limited, however, to the precise embodiments and variations described. Various changes, modifications and equivalents could be effected by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims. It is expressly intended that all such changes, modifications and equivalents which fall within the scope of the claims are embraced by the claims.
Number | Date | Country | Kind |
---|---|---|---|
2012-067127 | Mar 2012 | JP | national |
This application is a continuation of International Application No. PCT/JP2013/001539 filed on Mar. 8, 2013, and claims priority to Japanese Application No. 2012-067127 filed on Mar. 23, 2012, the entire content of both of which is incorporated herein by reference.
Number | Date | Country | |
---|---|---|---|
Parent | PCT/JP2013/001539 | Mar 2013 | US |
Child | 14494151 | US |