JPH0910214A - Ultrasonic catheter - Google Patents

Abstract

PURPOSE: To prevent leakage even when transfer liquid in injected by high pressure by forming the injection port of liquid on an at-hand side of a catheter, forming a sealing member for turning a part between an at-hand side and a tip side of the injection port fluid-tight on the at-hand side of the injection port and mechanically fixing or releasing a driving shaft by the sealing member. CONSTITUTION: A signal line 7 is incorporated in the driving shaft 6 and electrically connected to the electric contact points 61 and 62 of the receptacle 32 of an external drive source 8 through the electric contact points 51 and 52 of the connector 31 of an at-hand side operation part 40 and the driving shaft 6 is detachably mechanically connected to the external driving part 8 by the fitting part 33 of the at-hand operation part 40. The at-hand operation part 40 is provided with a cylindrical seal 41 which is the elastic body of resin such as rubber and elastomer, etc., provided with an inner surface shape for which a part of an inner diameter is narrowed, a seal operation part 42 provided with a screw mechanism for smashing the seal 41 and the injection port 43 for injecting the ultrasonic transfer liquid 9 from an outside.

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 by inserting it into a body cavity such as a blood vessel or a blood vessel.

[0002]

BACKGROUND OF THE INVENTION Traditionally, the coronary arteries of the heart and other small blood vessels,
Alternatively, there is known an ultrasonic catheter which is inserted into a blood vessel such as a bile duct to display a cross-sectional image of a lumen and measure blood flow. This ultrasonic catheter is, for example, as shown in FIG. 1, a drive transmission shaft for transmitting a driving force for rotating or reciprocating the ultrasonic transducer 3 provided at the tip of a hollow catheter shaft 2 inserted into a body cavity. 6, a signal line 7 for connecting the vibrator 3, the external electric circuit 5 and the drive source 8 is built in, and the drive shaft is mechanically driven by the external drive source 8 to scan ultrasonic waves to display an image. An ultrasonic catheter that displays an ultrasonic image by the device 1 is known. In this case, in order to efficiently transmit and receive ultrasonic waves in the gap between the ultrasonic transducer 3 and the catheter shaft 2, the drive shaft 6
In order to improve the slidability of the catheter shaft 2, it must be filled with an ultrasonic wave transmitting liquid 9 such as water.

When inserting the ultrasonic catheter into the body cavity, it is necessary to perform a priming operation in which the catheter shaft is preliminarily filled with the ultrasonic wave transmitting liquid 9, and after the insertion into the body cavity, the bubbles contained in the transmitting liquid. It is necessary to perform a flushing operation in order to prevent the adherence to the vibrator and the inflow of blood.
Therefore, a port 11 for injecting this ultrasonic transmission liquid into the catheter is provided on the catheter proximal side. In addition, a seal 12 is provided on the proximal side so that the ultrasonic transmission liquid does not leak from the proximal end of the catheter during priming or flushing and does not impair the rotation or translational movement of the drive shaft 6.

[0004]

However, in an ultrafine ultrasonic catheter having an outer diameter of 3 mm or less, particularly an outer diameter of 1 mm or less, which is inserted into a thin blood vessel such as a coronary artery,
Since the gap between the drive shaft 6 and the catheter shaft 2 becomes very narrow, in order to inject the ultrasonic transmission liquid 9 to the tip of the catheter, it must be injected from the port 11 at a pressure of several atmospheres or more. At this time, in the conventional seal, since the liquid leaks out from the slight gap between the drive shaft 6 and the seal 12, it is difficult to inject the ultrasonic transmission liquid to the distal end portion of the catheter.

Therefore, it is an object of the present invention to provide a sealing mechanism which does not leak even if a transmission liquid is injected at a high pressure in the ultrasonic catheter.

[0006]

The object is to incorporate a drive shaft for transmitting a mechanical driving force from a proximal side to a distal side into a catheter to be inserted into a body cavity and use the inside of the distal side of the catheter. An ultrasonic catheter having an ultrasonic transducer on its side and having a mechanism for directly or indirectly rotating or translating the transducer, wherein a liquid injection port provided on the proximal side of the catheter and the injection port Ultrasonic wave characterized in that it has a seal member that is located on the hand side of the device and makes the space between the hand side and the tip side liquid-tight, and that the seal member can mechanically fix or release the drive shaft Achieved by catheter.

The liquid tightness obtained by the sealing member is preferably at least 1 atm or more.

Further, it is preferable to use a flexible resin as the seal member.

[0009]

2 is an axial sectional view showing the structure of the distal end portion of an ultrasonic catheter 10 of the present invention, and FIG. 3 is a sectional view showing the structure of a transducer 20 of the ultrasonic catheter of the present invention. The ultrasonic transducer 23 is formed by depositing electrodes 22 on both surfaces of a piezoelectric body 21 made of PZT (lead zirconate titanate), PVDF (polyvinylidene fluoride) or the like at the tip of the catheter by printing or the like. A backing material 24 made of a resin such as epoxy, urethane, or acrylic that absorbs and attenuates ultrasonic waves is provided on the back surface side. Back material here 24
As shown in FIG. 3A, the thickness difference D on the back side is λ /
4 (where λ is the wavelength in the backing material at the transmission frequency) is provided so that the reflected wave from the back surface of the backing material 24 is canceled by interference, or as shown in FIG. 3B. So that the low acoustic impedance layer 26
(Z = 1 × 10 ⁶ Kg / m ^{2 s to} 8 × 10 ⁶ Kg / m ² s) and the high impedance layer 27 (Z = 20 × 10 ⁶ kg / m ² s or more) are alternately laminated. It may be a back material that reduces the influence of reflected waves from the back surface of the back material 24.

On the ultrasonic wave transmitting / receiving surface side of the vibrator 23, a matching layer 28 for acoustic matching with the ultrasonic wave transmitting liquid is formed. The acoustic impedance Z of the matching layer has a characteristic of Z0 ≦ Z ≦ Z1 where Z0 is the acoustic impedance of the piezoelectric body and Z1 is the acoustic impedance of the ultrasonic wave transmitting liquid. For example, water (Z
0 = about 1.5 × 10 ⁶ Kg / m ² s) and PZ as a piezoelectric body
When T (Z1 = about 30 × 10 ⁶ Kg / m ² s) is used, Z = 3 to 7 × 10 ⁶ Kg / m ² s is suitable for the matching layer. Matching layer 5
A thickness of 0 is suitable around λ / 4, where λ is the wavelength in the matching layer at the transmission frequency. In this example, the number of matching layers is one, but the number of matching layers may be two or more.

The conductors 71 of the signal line 7 covered with the insulator 72 are connected to the electrodes 22 on both sides of the vibrator 23.

FIG. 4 and FIG. 5 are axial sectional views showing a hand operation portion of the ultrasonic catheter of the present invention. As shown in FIG. 4, the signal line 7 is built in the drive shaft 6 and electrically connected to the receptacles 61 and 62 of the external drive source 8 via the electrical contacts 51 and 52 of the connector 31 of the proximal side operation unit 40. To be done.

The drive shaft 6 is detachably and mechanically connected to an external drive unit 8 such as a motor at a fitting unit 33 of the hand operation unit 40.

As shown in FIG. 4, a seal 41 having a cylindrical inner surface with a narrow inner diameter, which is a resin elastic body such as rubber or elastomer, is crushed in the hand operation section 40. A seal operating portion 42 having a screw mechanism for injection and an injection port 43 for injecting the ultrasonic transmission liquid 9 from the outside are provided.

As the seal 41, an elastic body such as thermoplastic resin, Teflon (registered trademark), silicon, or fluorine resin is used.

When priming the ultrasonic wave transmitting liquid 9 into the catheter shaft 2, the seal operating portion 42 is rotated and the seal 41 is crushed toward the catheter tip side as shown in FIG. Then, the drive shaft 6 is mechanically fixed and the catheter shaft 2 is kept in a liquid-tight state. Next, the ultrasonic wave transmitting liquid 9 is injected into the catheter shaft 2 from the injection port 43 using a syringe, an inflator for a PTCA balloon, or the like. The injection pressure depends on the clearance between the catheter shaft 2 and the drive shaft,
The atmospheric pressure is about 20 atm gauge pressure.

After completely filling the inside of the catheter shaft 2 with the liquid, the seal operating portion 42 is reversely rotated to restore the seal 41 to its original shape as shown in FIG. 5, and a gap 54 is formed between the seal 41 and the drive shaft 6. Provided and mechanically release the drive shaft 6.

Since this sealing mechanism is provided, priming can be completed easily without leakage of the injecting liquid from the hand side end of the hand operation unit 40, and even when the gap between the drive shaft and the catheter shaft is small and 10 μm to 100 μm. Priming is possible in a short time.

<Modification> FIGS. 6 and 7 show modifications of the present invention. In this modified example, by rotating the seal operating portion 57, the seal 56 formed of a resin elastic material such as rubber or elastomer is brought into close contact with the drive shaft 6, thereby mechanically fixing the drive shaft 6 and The inside of the catheter shaft is made liquid-tight (FIG. 6), and priming work is performed.

After the priming is completed, the seal 56 is released from the drive shaft 6 by rotating the seal operating portion 57 in the reverse direction (FIG. 7).

In the present invention, as shown in FIG. 8 (the operating portion at hand is not shown), the ultrasonic reflecting plate 4 provided at the distal end of the catheter is rotated or reciprocated by a drive shaft to scan ultrasonic waves. Even in this case, the same effect can be obtained.

[0022]

As described above, the catheter that is used by inserting it into the body cavity has a built-in drive shaft for transmitting a mechanical driving force from the proximal side to the distal side, and ultrasonic vibration is generated inside the distal side of the catheter. An ultrasonic catheter having a child and a mechanism for directly or indirectly rotating or translating the transducer, wherein a liquid injection port provided on the proximal side of the catheter and a proximal side of the injection port are provided. Since it has a seal member that is positioned and liquid-tight between the proximal side and the distal side, and the seal member can mechanically fix or release the drive shaft, the gap between the catheter shaft and the drive shaft is Is very narrow, and even in the case of 10 μm to 100 μm, the priming operation can be easily performed in a short time.

[Brief description of the drawings]

FIG. 1 is an axial cross-section of a conventional ultrasonic catheter and a configuration diagram of a system.

FIG. 2 is an axial cross-sectional view of the tip portion of the ultrasonic catheter of the present invention.

FIG. 3 is a sectional view of a transducer of an ultrasonic catheter of the present invention.

FIG. 4 is an axial cross-sectional view showing an ultrasonic catheter proximal operation unit of the present invention.

FIG. 5 is an axial cross-sectional view showing an ultrasonic catheter proximal operation unit of the present invention.

FIG. 6 is a cross-sectional view in the axial direction showing an ultrasonic catheter near-end operating portion according to a modified example of the present invention.

FIG. 7 is an axial cross-sectional view showing an ultrasonic catheter proximal operation unit of a modified example of the present invention.

FIG. 8 is a partial axial cross-sectional view showing a distal end portion of an ultrasonic catheter according to a modified example of the present invention.

[Brief description of reference numerals]

1: Image display device 2: Catheter shaft
3, 23: Transducer 4: Reflector 5: External electric circuit
6: Drive shaft 7: Signal line 71: Conductor
72: Insulator 8: External drive source 9: Ultrasonic transmission liquid 10: Ultrasonic catheter body 11, 43: Injection port 12: Seal 13: External drive unit 20: Transducer 21: Piezoelectric body 22: Electrode 24, 26, 27 : Back material
25: Concavo-convex part of back material 28: Matching layer 31: Connector
32: Receptacle 33: Fitting part 40: Hand operation part 4
1, 56: Elastic body seal 42, 57: Seal operation part 51, 52, 6
1, 62: Electrical contact 53: Bearing 54: Gap

Claims (3)

[Claims] 1. A drive shaft for transmitting a mechanical drive force from a proximal side to a distal side is built in a catheter to be inserted into a body cavity, and an ultrasonic transducer is provided inside the distal side of the catheter. An ultrasonic catheter having a mechanism for directly or indirectly rotating or translating a transducer,
A liquid injection port provided on the proximal side of the catheter, and a seal member located on the proximal side of the injection port for making the space between the proximal side and the distal side liquid-tight, and the sealing member serves to drive the drive shaft. An ultrasonic catheter characterized in that it can be mechanically fixed or released. 2. An ultrasonic catheter, wherein the liquid tightness obtained by the seal member is at least 1 atm or more. 3. The ultrasonic catheter according to claim 1, wherein a flexible resin is used as the sealing member.