JP2003210462A - Ultrasonic catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably construct a fine ultrasonic image by easily eliminating bubbles around an ultrasonic transducer. <P>SOLUTION: In this ultrasonic catheter 1, a drive shaft 4 for transmitting mechanical driving force from the proximal end to the distal end is built in a catheter tube 21, and a housing 50 provided with the ultrasonic transducer 51 is connected to the drive shaft 4. A housing coil 52 connected to the tip side of the housing 50 is hollow, and a passage communicating with an internal space is formed at least at one part of a sidewall. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic catheter used for displaying a cross-sectional image of a lumen by inserting it into a body cavity such as a blood vessel, a blood vessel, a digestive tract or the like. Is.

[0002]

2. Description of the Related Art As a treatment for a vascular stenosis causing a myocardial infarction or the like, a surgical technique has been performed in which a catheter is used for percutaneous treatment. In this surgical technique, a stenosis is spread with a dilatation catheter having a balloon at the tip,
There are various methods such as a method of indwelling a metal tube called a stent, a method of cutting a stenosis by rotating a grindstone or a cutter with an instrument called a rotablator, and a preferable method according to the nature of the stenosis and the patient's condition. Is selected. The ultrasonic catheter is mainly used for percutaneous treatment of a vascular stenosis to observe the properties of the stenosis and to assist the decision to select a treatment method. It is also used to observe the condition.

A conventional ultrasonic catheter is composed of a flexible imaging core (an ultrasonic transducer unit for transmitting and receiving ultrasonic waves and a drive shaft for rotating the same) and a catheter tube for covering them. Ultrasound catheter inspection generally carries an ultrasonic transducer unit located near the distal end of the ultrasonic catheter along the guide wire that has reached the vascular stenosis, which is the affected area, to the affected area, where ultrasonic waves are transmitted. Ultrasonic observation is performed by operating the transducer unit to continuously observe ultrasonic tomographic images before and after the affected area.

In some of such ultrasonic catheters, a tightly wound housing coil is connected to the distal end side of the ultrasonic transducer unit. This is for the purpose of softening the strength change because there is a possibility that a kink (bending) of the catheter tube may occur if the strength change is large between the part where the imaging core is present inside the catheter tube and the part where it is not present. And the purpose of stabilizing the rotation of the ultrasonic transducer unit are compatible with each other.

In such an ultrasonic catheter, an image signal cannot be acquired unless there is an ultrasonic wave propagating substance that propagates ultrasonic waves between the ultrasonic transducer and the blood vessel wall. Prior to insertion into a patient, a priming operation is performed in which the inside of the catheter tube is replaced with air from a liquid such as physiological saline. If the priming work is not performed sufficiently and minute bubbles remain on the surface of the ultrasonic transducer, the bubbles will block or scatter the ultrasonic waves by strong reflection and disturb the image quality significantly. It is required to eliminate bubbles from the.

[0006]

However, since the housing coil described above has a close-wound structure, air bubbles remain inside the coil, and these air bubbles move to the surface of the ultrasonic transducer during ultrasonic observation, and the observation is performed. There was a possibility of blocking.
Also, when the high-pressure liquid is injected during the priming work, the drive shaft expands, and the housing coil enters the portion of the catheter tube on the distal end side where the inner diameter is small, and the gap that forms the flow path becomes small, making it difficult to eliminate air bubbles. Was becoming.

The present invention has been made in view of the above problems, and makes it possible to maintain good kink resistance and rotational stability while leaving no bubbles and achieving good ultrasonic image construction. With the goal.

[0008]

Such an object is achieved by the present invention described in (1) to (4) below.

(1) A catheter tube that is used by inserting it into a body cavity or a lumen is used, and a drive shaft that transmits a mechanical driving force from the proximal end side to the distal end side is built in the catheter tube, and the drive shaft is driven. A housing provided with an ultrasonic transducer is connected to the shaft on the tip side of the catheter tube, and an elastic body connected to the housing on the side opposite to the side to which the drive shaft is connected and the drive shaft are connected to each other. An ultrasonic catheter having a hand mechanism unit connectable to an external drive source for rotation, wherein the elastic body is hollow, and a flow path communicating with the internal space of the elastic body is formed at least at one side wall. An ultrasonic catheter characterized in that

(2) The elastic body is a coil in which at least a part of the elastic body is sparsely wound.
The ultrasonic catheter according to 1.

(3) The ultrasonic catheter as described in (1) or (2) above, wherein the tip of the elastic body has a reduced diameter.

(4) The housing according to any one of the above (1) to (3), characterized in that the housing has a passage that allows the surface of the ultrasonic transducer and the internal space of the elastic body to circulate. Ultrasonic catheter.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The ultrasonic catheter of the present invention will be described below in detail with reference to the preferred configuration examples shown in the accompanying drawings.

FIG. 1 is an overall side view showing an embodiment of the ultrasonic catheter of the present invention.

FIG. 2 is a longitudinal sectional view of the proximal portion of the catheter shown in FIG.

FIG. 3 is a longitudinal sectional view of the distal end portion of the catheter shown in FIG.

As shown in FIGS. 1, 2 and 3, the ultrasonic catheter 1 is composed of an insertion portion 2 for inserting into a body cavity and a hand portion 3.

The insertion portion 2 has a hollow catheter tube 21 having a priming lumen 20 opened on the distal end side thereof, and a drive shaft 4 attached over substantially the entire length of the tube 21 and rotatably contained in the tube 21. The drive shaft 4 is made of, for example, a multi-layered multi-layered contact coil or the like, which is flexible and has a characteristic that rotation can be transmitted well from the hand side to the tip side.

An ultrasonic transducer unit 5 is attached to the tip of the drive shaft 4, and a signal line 54 is inserted and connected through the inside of the drive shaft 4. The ultrasonic transducer unit 5 includes a housing 50 formed by cutting out a metal pipe fixed to the tip of the drive shaft 4, and an ultrasonic transducer 51 mounted in the housing 50.

A housing coil 52, a part of which has been processed into a coiled coil, is fixed to the tip of the ultrasonic transducer unit 5. A part of the front end side of the housing coil 52 is tightly wound and has a tapered diameter. Tube 21
In order to confirm the position of the ultrasonic catheter 1 under the X-ray image, a marker coil 22 formed of an X-ray contrasting metal such as platinum or tungsten is attached inside, and the tip of the housing coil 52 is The marker coil 22 is partially inserted inside. This allows the tube 21
Since some member is present throughout the lumen of the tube, and there is no point of sudden change in physical properties, the tube is unlikely to be bent (kink). Further, the base side of the housing coil 52 is also formed in a tightly wound shape, which is a structure advantageous in terms of strength for brazing with the housing 50.

A guide wire lumen 6 is provided at the tip of the tube 21, and the guide wire lumen 6 is provided.
Positions the proximal end opening 61 closer to the tip side than the ultrasonic transducer unit 5 so as not to obstruct the ultrasonic signal.

The ultrasonic oscillator 51 in the ultrasonic oscillator unit 5 transmits and receives ultrasonic waves toward the tissue in the body cavity. The electrical connection with the ultrasonic transducer 51 is the signal line 5 as described above.
4 and is operated by an external drive source (not shown) connected to the hand part 3.

The proximal portion 3 has a hub 31 having a port 30 for injecting a physiological saline solution for priming, and a sealing means 3 for preventing the fluid in the catheter from leaking to the proximal opening.
Have two. A pipe 41 is connected to the base end side of the drive shaft 4, and a rotor 33 for transmitting the rotation of an external drive source (not shown) to the drive shaft 4 is connected to the pipe 41 through a sealing means 32 including an O-ring 321. There is. The rotor 33 is covered with a joint 34 joined to the hub 31. A male connector 35 connected to the base end of the signal line 54 is installed on the rotor 33, and by connecting the hand portion 3 to an external drive source, it is electrically connected to a female connector (not shown) provided in the external drive source. .

Next, the operation method and operation of the present invention will be described. FIG. 4 is a schematic diagram of the flow of physiological saline solution by priming in the ultrasonic catheter 1 of FIG.

Prior to the procedure, the ultrasonic catheter 1 needs to be primed and filled with physiological saline. The presence of residual air is not preferable because bubbles may adhere to the ultrasonic transducer during the procedure and the image may deteriorate.

The priming work of the ultrasonic catheter 1 in this embodiment is performed by the port 30 of the hub 31 of the hand portion 3.
Then, a physiological saline solution is injected using a syringe or the like (not shown). The physiological saline solution escapes into the priming lumen 20 through a gap between the inner wall surface of the tube 21 and the surface of the drive shaft 4.
At this time, the drive shaft 4 formed by the coil
However, the housing coil 52 penetrates deeper into the marker coil 22 due to a slight expansion due to the injection pressure of physiological saline. Due to this phenomenon, the housing coil 52 approaches the inlet of the priming lumen 20 and the gaps between the respective parts are narrowed, so it is not easy to circulate the physiological saline or air in this state, but according to the present embodiment, The physiological saline solution flows into the inside of the housing coil 52 from the loosely-wound portion of the housing coil 52 and smoothly flows, so that the vicinity of the ultrasonic transducer 51 is easily filled with the physiological saline solution. For this reason, it is difficult for bubbles to adhere to the ultrasonic transducer 51, and it is possible to prevent the image from deteriorating.

In a more preferred embodiment, the hole 53 is formed through the surface of the ultrasonic transducer 51 into the internal space of the housing coil 52, and the housing coil 52 is loosely wound to form the ultrasonic transducer 51. The bubbles on the surface of the tube are easily removed, and the flow in the housing coil 52 is more active, so that the bubbles in the tube 22 can be removed more easily.

Although the ultrasonic catheter of the present invention has been described above based on the illustrated embodiment, the present invention is not limited to this.

For example, all of the housing coils may be loosely wound, and the tip may not be tapered. Further, one to several holes may be formed on the side surface of a flexible circular tube such as a rubber material.

[0030]

As described above, according to the ultrasonic catheter of the present invention, by providing the liquid flow path on the side wall of the housing coil in front of the ultrasonic transducer, the characteristics suitable for the ultrasonic catheter ( Since air bubbles can be efficiently removed while maintaining kink resistance and rotational stability), it is possible to contribute to improved image stability and patient safety.

[Brief description of drawings]

FIG. 1 is an overall side view showing an embodiment of an ultrasonic catheter of the present invention.

2 is a longitudinal sectional view of a proximal portion of the ultrasonic catheter shown in FIG.

3 is a vertical cross-sectional view of the distal end portion of the ultrasonic catheter shown in FIG.

FIG. 4 is a schematic diagram of a flow of a physiological saline solution at the distal end portion of the ultrasonic catheter 1.

[Explanation of symbols]

1 ... Ultrasonic catheter 2 ... Catheter tube 3 ... Connector 4 ... Drive shaft 5 ... Ultrasonic transducer unit 6 ... Guide wire lumen 50 ... Housing 51 ... Ultrasonic transducer 52 ... Housing coil 53 ... hole 54 ... Signal line

Claims (4)

[Claims] 1. A catheter tube which is used by being inserted into a body cavity or a lumen, and a drive shaft for transmitting a mechanical drive force from a proximal end side to a distal end side is incorporated in the catheter tube, and the drive shaft. Is connected to a housing equipped with an ultrasonic transducer on the distal end side of the catheter tube, and an elastic body connected to the opposite side of the housing to which the drive shaft is connected and the drive shaft are rotated. An ultrasonic catheter having a hand mechanism unit connectable to an external drive source, wherein the elastic body is hollow, and a flow path communicating with the internal space of the elastic body is formed at least at one side wall. An ultrasonic catheter characterized in that 2. The ultrasonic catheter according to claim 1, wherein the elastic body is a coil in which at least a part of the elastic body is sparsely wound. 3. The ultrasonic catheter according to claim 1, wherein the tip of the elastic body has a reduced diameter. 4. The ultrasonic catheter according to claim 1, wherein the housing has a passage that allows the surface of the ultrasonic transducer and the internal space of the elastic body to circulate.