JPH0984879A - Blood vessel expansion apparatus using hot balloon catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blood vessel expansion apparatus using a hot balloon catheter in which heating temp. is easily controlled and local heating can be performed and reduction of the diameter can be performed and which is easily manufactured. SOLUTION: This blood vessel expansion apparatus is constituted of a hot balloon catheter 1 and a heater temp. controlling part 2. A heater 14 serving also as a temp. sensor is provided in the balloon 13 or adjacently to the balloon 13 at the apex part of the hot balloon catheter 1 and heating and temp. controlling of the heater 14 is performed by means of the heater temp. controlling part 2 in which feeding of an electric current for heating to the heater 14 and receiving of a temp. detecting signal from the heater 14 can be automatically switched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vasodilator using a hot balloon catheter used for so-called vasodilation, which expands a stenosis of a blood vessel, particularly a heart blood vessel due to arteriosclerosis.

[0002]

2. Description of the Related Art Conventionally, as a hot balloon catheter used for vasodilation, a catheter having a balloon capable of inflating and deflating at its distal end has a high-frequency energizing electrode integrally incorporated in an inner tube. Things have been proposed. When treating a stenosis of a blood vessel, high-frequency dielectric heating heats the stenosis at an appropriate temperature to improve elastic fiber extension of the tunica media, and also plasticizes thrombus and other lipids. While doing so, the balloon is pressurized and inflated to mechanically crush the thrombus or atheroma, the blood vessel wall is extended to expand the stenosis, and the blood flow is improved (Japanese Patent Laid-Open No. 3-251258, Kaihei 4-24
6367, JP-A-6-98937, etc.).

The balloon catheter disclosed in Japanese Unexamined Patent Publication (Kokai) No. 3-251258 has a high-frequency energizing electrode provided on the outer circumference of a hollow catheter shaft. A high-frequency voltage is applied between this electrode and an electrode plate arranged outside the living body to form a balloon. This is a method for locally dielectrically heating a narrowed portion of a blood vessel wall having a large dielectric loss rate in contact with the film. In addition, JP-A-4-24636
The balloon catheter of Japanese Patent No. 7 is provided with a high-frequency energizing electrode on the catheter shaft in the balloon and a plurality of small holes for perfusing a cooling liquid in the catheter shaft in the balloon. The intimal surface of the blood vessel that contacts the balloon is not cauterized. The hot balloon catheter disclosed in Japanese Patent Laid-Open No. 6-98937 has a shaft having a high frequency energizing function and a guide wire having an electrode portion at the distal end thereof. The tip of the hot wire catheter is inserted through the guide wire having the high frequency energizing function. A high-frequency voltage is applied between the electrode part of the abdomen and the counter electrode plate applied to the back of the patient, etc., whereby the vicinity of the stenotic site of the blood vessel is dielectrically heated.

However, these conventional hot balloon catheters have the drawback that it takes time to prepare for the procedure because the counter electrode is separately provided outside the body. In addition, since high-frequency current is applied across the living body and the distance between the electrodes is long, power consumption is large, and it is difficult to control the heating temperature. Therefore, it is difficult to locally heat the target site only. Had. On the other hand, there is also proposed a hot balloon catheter which is provided with a high-frequency current-carrying electrode and a temperature sensor inside the balloon so that the temperature of the electrode is controlled by a detection signal of the temperature sensor (Japanese Patent Laid-Open No. 5-212118, Japanese Patent Application Laid-Open No. 5-212118). Kaihei 5-2
No. 28215), however, because these are also heating of the stenosis part using high frequency, there is a drawback that an error is likely to occur in the temperature measurement and the blood vessel may be cauterized.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. It is easy to control the heating temperature, local heating is possible, diameter reduction is possible, and manufacturing is possible. An object of the present invention is to provide a vasodilator using an easy hot balloon catheter.

[0006]

In order to solve the above-mentioned problems, the present invention comprises a balloon at the tip and a heater also serving as a temperature sensor is provided inside or adjacent to the balloon. The hot balloon catheter, an energizing means for supplying a heating current to the heater of the hot balloon catheter, a temperature detecting means for receiving a temperature detection signal from the heater, a heating current supply to the heater and a heater A blood vessel dilating device comprising a switching means for automatically switching between reception of a temperature detection signal and temperature control means for controlling a current supplied to a heater based on the temperature detection signal received by the temperature detection means are doing.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing an embodiment of the temperature control unit of FIG. As shown in FIG. 1, the vasodilator of the present invention comprises a hot balloon catheter 1 and a heater temperature control unit 2. A heater 14 also serving as a temperature sensor is provided in the balloon 13 or adjacent to the balloon 13 at the tip of the hot balloon catheter 1. The heating and temperature control of the heater 14 is controlled by a heating current to the heater 14. This is performed by the heater temperature control unit 2 which can automatically switch between supply and reception of the temperature detection signal from the heater 14.

The hot balloon catheter 1 includes an outer tube 11, an inner tube 12 inserted into the outer tube 11, a distal end portion of the outer tube 11 and a balloon 13 adhesively fixed to the distal end portion of the inner tube 12, and a balloon 13. The heater 14 is provided inside or adjacent to (including proximity to) the balloon 13 and also serves as a temperature sensor. The heater 14 is connected to the heater temperature control unit 2 via a lead wire 15. The outer tube 11 and the inner tube 12 are flexible resins such as olefin resins such as ethylene-vinyl acetate copolymer, polyethylene, polypropylene and ethylene-propylene copolymer, and polytetrafluoroethylene and tetrafluoroethylene-. A tube made of fluororesin such as propylene hexafluoride copolymer, polyester, polyvinyl chloride, polyurethane, polyethylene terephthalate (PET), polyamide, etc. The inner tube 12 is balloon-expanded in the inner lumen of the outer tube 11. It is inserted so as to secure a passage (lumen 16) for liquid injection.

A balloon 13 is provided on the outer wall of the inner tube 12.
A heater 14 that also serves as a temperature sensor is provided inside (or may be adjacent to) the balloon 13. As a material for forming the heater 14, a stainless pipe to which a constantan wire is connected (a thermocouple) or the like is preferably adopted.

The balloon 13 is a thin film having a wall thickness of generally 0.001 to 0.1 mm, which is adhered to the tip portions of the inner tube 12 and the outer tube 11 by a method such as an adhesive or heat welding, and has appropriate toughness. A material with strength, for example
Ethylene-butylene-styrene block copolymer mixed with low molecular weight polystyrene and optionally polypropylene, polyvinyl chloride, polyester, thermoplastic rubber, silicone-polycarbonate copolymer, ethylene-vinyl acetate copolymer , Polyethylene terephthalate, polyamide, etc. are preferably adopted.

As shown in FIG. 2, the heater temperature control unit 2 is based on a heating power source 21, a temperature measuring unit 22 that receives a temperature detection signal from the heater 14, and temperature data measured by the temperature measuring unit 22. Control circuit 23 for controlling the electric current supplied to the heater 14 by the heater, and this control circuit 2
Based on the heating control signal from the heater 3, the heater 14 is connected to the heating power source 21, and the heater 14 and the temperature measuring unit 22 are connected.
It comprises a switching means 24 for automatically switching the connection with.
The automatic switching of the connection between the heater 14 and the heating power source 21 and the temperature measuring unit 22 is normally performed at intervals of 0.1 seconds to 0.5 seconds, but the connection time between the heater 14 and the heating power source 21 Is longer in the initial stage of heating when the temperature of the heater 14 is lower than the connection time between the heater 14 and the temperature measuring unit 22, and becomes shorter after the temperature of the heater 14 reaches a predetermined temperature. Then, when the temperature of the heater 14 becomes higher than a predetermined temperature (when the temperature measuring unit 22 receives a temperature detection signal higher than the predetermined temperature), a heating interruption signal is output from the control circuit 23 to heat the heater 14 and the heater 14. Connection with the power supply 21 for
The connection between the heater 14 and the temperature measuring unit 22 is automatically switched, and the heating of the heater 14 is interrupted by the interruption of the heating of the heater 14.
When the temperature becomes lower than a predetermined temperature (when the temperature measuring unit 22 receives a temperature detection signal lower than the predetermined temperature), a heating start signal is output from the control circuit 23 and the heater 14 and the temperature measuring unit 22 Connection is heater 14 and heating power supply 2
The connection with 1 is automatically switched. It should be noted that the heater temperature control unit 2 is provided with a temperature display unit 25 so that the temperature measurement unit 22
You may make it display the temperature detected by.

Next, the use of the vasodilator of the present invention will be described with reference to FIGS. 1 and 2. First, a hot balloon catheter is percutaneously inserted into a blood vessel, and the tip portion of the inner tube 1 is positioned beyond the narrowed portion of the blood vessel. At this time, the balloon 3 is located exactly at the stenosis site of the blood vessel. When saline or the like as a fluid for inflating the balloon is injected into the balloon 3 via the lumen 8, the balloon 3 expands and presses the stenosis site. Next, turn on the switch (not shown) of the heater temperature control unit 2
Then, the connection of the heater 14 and the heating power source 21 and the connection of the heater 14 and the temperature measuring unit 22 are alternately repeated by the switching means 24, and the energization of the heater 14 and the temperature measurement of the heater 14 are performed. Repeated alternately. The connection time with the heating power source 21 is long in the initial stage of heating when the temperature of the heater 14 is low, and is short after the temperature of the heater 14 reaches a predetermined temperature. Then, when the temperature of the heater 14 becomes higher than a predetermined temperature, the connection between the heater 14 and the heating power source 21 is automatically switched to the connection between the heater 14 and the temperature measuring unit 22, and the heating of the heater 14 is interrupted. When the temperature of the heater 14 becomes lower than a predetermined temperature, the connection between the heater 14 and the temperature measuring unit 22 is automatically switched to the connection between the heater 14 and the heating power source 21. In this way, the narrowed portion of the blood vessel is expanded by heating and compression.

[0013]

As is apparent from the above description, by adopting the vasodilator of the present invention, the heating temperature of the heater can be accurately measured and controlled, so that it is better than the conventional one. The blood vessel stenosis 2 can be expanded.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing an embodiment of a heater temperature control unit of FIG.

[Explanation of symbols]

 1 Hot Balloon Catheter 11 Outer Tube 12 Inner Tube 13 Balloon 14 Heater 15 Lead Wire 2 Heater Temperature Control Section 21 Heating Power Supply 22 Temperature Measuring Section 23 Control Circuit 24 Switching Means

Claims (1)

[Claims] 1. A hot balloon catheter comprising a balloon at its distal end and a heater also serving as a temperature sensor provided inside or adjacent to the balloon.
Energizing means for supplying a heating current to the heater of the hot balloon catheter, temperature detecting means for receiving a temperature detection signal from the heater, supply of heating current to the heater and reception of a temperature detection signal from the heater And a temperature control means for controlling the current supplied to the heater based on the temperature detection signal received by the temperature detection means.