JPH11244248A - Guide wire type stromuhr - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a guide wire type stromuhr provided with a guide wire type or semiconductor type pressure sensor and/or an electrode for intracardiac electrocardiogram capable of measuring a blood stream in a microvessel such as coronary artery particularly in catheter treatment such as percutaneous angioplasty and percutaneous coronary angioplasty. SOLUTION: In a stainless guide wire having an outside diameter of 0.3 to 1.1 mm and a lumen, a part having a length of 10 to 30 mm including a round part at a tip thereof is a tubular coil made of a platinum wire allowing not the penetration of X ray, a micro wiring connecting an external equipment with a temperature sensing member disposed in a guide wire opening part is disposed in the lumen of the guide wire, a temperature of a blood stream thermally diluted by cooling salt water poured through a flexible tubule is sensed by a temperature sensing part in the opening part, and a blood stream flow velocity F=(C1 Q1 /C0 T0 )ΔT/ΔS and a blood stream Q=Σ(C1 Q1 /C0 T0 ) dTdS are measured from a temperature change curve up to the time when the temperature of blood stream becomes balanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention measures blood flow in intracardiac blood vessels in clinical electrophysiological examination (EPS), percutaneous angioplasty (PTA), percutaneous coronary angioplasty (PTCA), and the like. More specifically, the main body of the blood flow meter is an EP.
In a clinical examination, PTA, PTCA treatment, a guide wire is inserted and guided into a target vascular site, and the heart is guided through a cooled physiological saline injected by a temperature sensing member provided at the distal end of the guide wire. The present invention relates to a guidewire-type blood flow meter for measuring a blood flow velocity and a blood flow of an internal blood vessel, particularly a microvascular such as a coronary artery. Furthermore, the present invention further provides a guide wire having a pressure sensor and / or an electrode for an intracardiac electrocardiogram, wherein the main body is provided with a blood pressure measurement and / or an electrocardiogram measurement at an intracardiac blood vessel site. The present invention also relates to a guidewire type blood flow meter for measuring a blood flow velocity and a blood flow.

[0002]

2. Description of the Related Art In medical practice related to the heart, such as clinical and surgical operations, that is, monitoring and measurement during cardiac catheterization or catheter treatment, that is, monitoring during medical procedures such as PTCA and PTA, parameters such as electrocardiogram and blood pressure are extremely large. It is important, and since these are deeply related to the behavior of blood flow in the intracardiac blood vessels, it is also necessary to synchronize and measure the blood flow velocity or blood flow in each part of the heart. Is extremely important to

[0003] As described above, blood flow measurement is indispensable for such clinical examination and treatment of the heart. Conventionally, generally used blood flow measurement includes indirect and direct methods. One of the indirect methods is Swangantz (S
wan-Ganz) thermodilution (thermodilution) catheterization. This method is based on a thermodilution method in which a cooling physiological saline is injected from a catheter, and a blood flow velocity is calculated from a temperature change until a temperature of a blood flow thermally diluted by a thermocouple provided on the catheter reaches an equilibrium temperature. It is said that. Similarly, there is an ultrasonic Doppler blood flow meter as an indirect method, which emits ultrasonic waves from outside the body to the blood, receives reflected waves from the blood, and obtains blood from a change in frequency based on the Doppler effect due to the blood flow of the reflected waves. This is for obtaining the flow rate.

On the other hand, as a direct method, there is an electromagnetic blood flow method of measuring a blood flow via electromagnetic waves induced by electromagnetic induction from a probe which encloses a blood vessel which is incised and drawn out during surgery from around the blood vessel. Any of the direct laws, including the direct law of
This is a measurement method that can be performed only in surgical incision surgery.

[0005] Both these indirect and direct methods are currently
Although widely used in the medical field,
Both have their strengths and weaknesses, and recently there have been proposals for improvement of the indirect method that does not require surgical operation.

For example, Japanese Patent Application Laid-Open No. Hei 5-137725 discloses that an ultrasonic Doppler blood flow measuring unit using a plurality of ultrasonic transducers continuously measures a blood flow through a catheter provided with a plurality of ultrasonic transducers. A measurement method for continuously monitoring blood flow from both a thermodilution measurement unit for injecting physiological saline separately provided for measuring the measured value and measuring blood flow is described. .

Further, for the purpose of measuring blood flow in a minute blood vessel part, which cannot be measured by the conventional catheter method, a catheter is inserted through a guide wire used to guide the catheter to the target part. Attempts have been made to measure blood flow.

For example, Japanese Patent Application Laid-Open No. 2-279132 describes a guide wire type blood flow meter which focuses on a guide wire which is excellent in operability in a minute blood vessel. That is, the lumen of the guide wire has electrodes for measuring the cross-sectional area of the blood vessel and the blood flow rate of the coronary artery, and the distal end of the guide wire has two electrodes, a base electrode and a terminal electrode separated by an insulator. After a voltage is impressed via the electrodes, the blood flow velocity is determined from the current behavior between the two electrodes based on the linear relationship between the blood flow velocity and the current flow. Is to be measured.

Further, Japanese Patent Application Laid-Open No. 5-329119 discloses that a thermocouple provided on a guide wire inserted into a lumen of a catheter is heated at a high frequency to transmit a certain amount of heat to a blood flow. There has been proposed a method of electrically measuring a temperature change of a temperature sensing chip provided in a unit to obtain a blood flow.

[0010]

As described above, catheter treatment for heart disease has rapidly spread, and in particular, percutaneous coronary angioplasty (PTCA) performed using a balloon catheter for coronary stenosis has been used for cardiac treatment. Many catheterization methods are also used for treatments such as percutaneous angioplasty (PTA), which is performed as dilation of large blood vessels and peripheral blood vessels.

[0011] However, these treatments are always performed under the monitoring of the patient's condition. Conventionally, an electrocardiogram (body surface electrocardiogram or intracardiac electrocardiogram), blood pressure monitoring, and the like are required, and in some cases, blood flow measurement is also required. And these monitoring are very important. In particular, there is a strong need for accurate blood flow measurement in microvessels and improvement of indirect methods that do not require surgery, including verification of results after PTCA and PTA surgery in microvessels such as coronary arteries. .

[0012] However, the blood vessel drawn and cut out by the indirect method of the blood vessel insertion type Swan Ganz, which is a typical blood flow meter of the above-mentioned indirect method and direct method, thermodilution catheter method of Swan-Ganz or surgical operation, is sandwiched by a probe for measurement. Both the indirect method and the direct method, including the direct method electromagnetic blood flow meter, have their advantages and disadvantages.

In other words, the most reliable direct blood flow meter at present can be used only during surgical operations,
The ultrasonic blood flow meter, which is the center of the indirect method, is not clear where the blood flow in the living body is measured, and the device combining the ultrasonic sensor and the computer for calculation is expensive, Even if such a sensor is provided on the catheter, the catheter is too thick to be measured on microvessels.

Furthermore, the Swan-Ganz thermodilution catheter method used for medical purposes as a general thermal flow meter uses a thermodilution curve obtained by sensing a temperature change with a built-in thermocouple or thermistor. The blood flow is obtained from the integration of the figure.For this reason, even if a low-temperature saline solution is injected or an electric current is passed through the built-in resistance heating element to heat it by electric heating, a large amount of heat change is required to measure the blood flow. The method of injecting the cooling saline solution is complicated, and the error is large, so that accurate measurement cannot be obtained. Also, even if the latter is supplied with electric heat, the blood flow is heated to 60 to 70 ° C. Therefore, there are various dangers. Moreover, the conventional catheter method has a problem that it is impossible to measure a blood flow in a minute blood vessel such as a coronary artery.

[0015] In view of the above problems, the present inventor has proposed:
As a result of intensive studies to improve the conventional indirect method of thermodilution catheter method, the present applicant has already filed Japanese Patent Application No. 9-1903.
Focusing on a guide wire with a semiconductor type pressure sensor excellent in insertability into fine details and operability described in the patent specification No. 07, and using a temperature compensating circuit built in this pressure sensor, the blood flow is measured. The present invention has been made based on the knowledge that blood flow can be measured by temperature sensing as in the conventional Swan-Ganz-type thermodilution catheter method.

Accordingly, an object of the present invention is to insert a blood flow meter into a blood vessel without the need for surgical operation to measure the blood flow, and to perform a thermodilution of a Swan Ganz using a conventional catheter. An object of the present invention is to provide a guidewire-type blood flow meter which enables measurement of blood flow in microvessels such as coronary artery, which cannot be measured by the method.

Another object of the present invention is to provide a guide wire type blood flow meter which is combined with an improved saline injection method in order to improve the measurement accuracy of the thermodilution method.

Another object of the present invention is to measure blood flow at an intracardiac vascular site alone, and to file a patent application filed with Japanese Patent Application Nos. Hei 9-190307 and Hei 9-190308.
Guide wire described in the specification of Japanese Patent Application Publication No. H10-107, the guide wire having a pressure sensor and / or a guide wire with an electrode for an electrocardiogram, thereby measuring blood flow in synchronization with accurate blood pressure measurement and electrocardiogram measurement in each part of the heart And a blood flow meter.

[0019]

According to the present invention, an outer diameter for inserting and guiding a catheter into the heart is 0.3 to 1.1 mm.
In a stainless steel guide wire, the tip of the tubular coil is made of a platinum wire that is radiopaque at a length of 10 to 30 mm, and is welded to the rounded tip or adjacent to the tubular coil. The stainless steel mantle tube has an opening that comes into contact with the blood flow, and the guide wire has a fine wire inside the lumen of the guide wire connecting the external device and the temperature sensing member provided in the opening, and the temperature of the opening is The sensing unit senses the temperature of the blood flow thermally diluted with the cooled physiological saline injected through the flexible tubule, and obtains the following equation from the thermodilution curve diagram of the blood flow recorded on an external device, F = C ₁ Q ₁ ΔT / C ₀ T ₀ ΔS [1] C _1, C ₀ ; respectively, cooled physiological saline and specific heat of blood, T _0, ΔT; temperature of blood, temperature of blood and physiological saline, respectively temperature difference between _{T 1 (ΔT = T 0 -T} 1 , (Provided that _{0 ≦ T 1 ≦ 20 ℃)} , Q 1; injection volume of the cooling saline (ml / min), ΔS; cooling saline is injected, the temperature of the temperature sensing portion has a minimum value Time to reach blood temperature T ₀ (min),
And Q = Σ (C ₁ Q ₁ / C ₀ T ₀ ) dTdS... [2] Blood flow velocity F (ml / min) and blood flow Q
(Ml) is provided.

In the blood flow meter, as the temperature sensing member, an allomer-chromel type thermocouple, a platinum resistance temperature detector, a semiconductor temperature-sensitive resistance element, or a thin film temperature sensor such as SiC, ZrN, Pt, etc. is preferable.

According to the present invention, in a guide wire type blood flow meter capable of measuring a blood flow in synchronization with a blood pressure and / or an electrocardiogram, the temperature sensing portion for measuring the blood flow has a silicon type pressure sensor for measuring blood pressure. A guide wire, which is provided as a temperature compensation circuit paired with a Whiston bridge circuit on the chip surface to measure blood flow in a blood vessel in synchronization with blood pressure measurement in the heart and / or electrocardiogram. A blood flow meter is provided.

In a guidewire type blood flow meter with a pressure sensor and / or an electrode for an intracardiac electrogram according to the present invention,
As a temperature sensing member assembled in the temperature compensation circuit, S
Thin-film temperature sensors such as iC, ZrN, and Pt are preferred.

Furthermore, in the present invention, in particular, in a minute blood vessel such as a coronary artery, in order to obtain an accurate measurement value with a small amount of heat change, a thermo-dilution is performed with a cooling physiological saline at a temperature sensing portion of an opening. To sense the blood flow temperature, the injection hole at the tip of the flexible thin tube connected to the external syringe is inserted directly into the microvessels, a predetermined amount of the saline is injected, and the blood flow temperature is sent to the external device. In order to record the thermodilution curve diagram of the temperature change up to equilibrium, 1. The flexible thin tube (fine injection tube) is a plastic tube having an outer diameter of 0.3 to 1.5 mm. 1 to 3 mm from the rounded end of the plastic tube
2. having one to four injection holes laterally at the site; 3. The injection amount of the saline is 0.5 to 3 ml; It is preferable that the plastic tube is resin-bonded to a guide wire of the main body of the blood flow meter.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Operation) The guide wire type blood flow meter according to the present invention has a guide wire whose main body is a helical fine diameter wound tightly with a fine stainless wire as already described above. The blood flow meter is a tubular wire, and the platinum tubular coil at the tip of the tubular wire serves as a marker as a dark part that is opaque to X-rays under X-ray fluoroscopy. Are easily inserted even in the minute blood vessels of the heart, and have a feature that the measurement site of the blood flow can be clarified. Temperature sensing provided at the distal end as a blood flow meter even in a coronary artery branching right and left so as to wrap the heart from the base of the aorta, for example, having a microvascular diameter of 4 mm or less, particularly 3 mm or less. The part can be easily and stably inserted into the target site.

Since the blood flow meter of the present invention is a thermodilution method, similarly to the conventional thermodilution catheter method of Swan-Ganz, it injects a cooled physiological saline, and uses a flexible thin tube for the injection. It is. In the present invention, a plastics flexible thin tube is suitably used as the thin tube. For example, a saline infusion catheter with a side port conventionally used by the Swan-Ganz method is used, and the blood flow meter of the present invention is used. Since the main body is a guide wire, it is inserted through the blood flow meter itself.

In normal thermodilution method, the temperature of the physiological saline injected is such that the blood temperature of the human body sensed by the temperature sensing unit can be regarded as approximately 37 ° C., and a clear temperature change needs to be given to the blood flow. Physiological saline cooled to at least about 10 ° C. below the blood temperature, preferably from 0 to 20 ° C., more preferably from 4 to 10 ° C., is injected from the side port.

The guide wire type blood flow meter according to the present invention
If the measurement site is a microvessel, the injection amount is 0.5 to
It has the characteristic that it can be appropriately selected and measured within a range of 4 ml, preferably 1 to 2.5 ml (see Examples described later). In the thermodilution method, since accurate measurement is expected as the injection is performed as quickly as possible, it is extremely desirable that the injection amount be reduced as in the examples described later.

If the microvessels are coronary arteries branching from the aorta so as to enclose the heart, the distal end of the main port of the catheter is placed above the blood flow at the measurement site through the blood flow meter which is also a guide wire. It is inserted into the coronary artery entrance (see FIG. 2). As a result, at the measurement site in the coronary artery, a blood flow with a reduced temperature that has been thermodiluted with the cooled saline flowing from the aorta flows, and the thermodiluted blood flow ends, and the blood flow becomes the blood temperature and the blood flow. A temperature change until equilibrium is measured over time by the temperature sensing member of the guide wire type blood flow meter of the present invention, and a thermo-dilution curve diagram of the temperature change as shown in FIG. Is recorded.

The blood flow velocity and blood flow measured by the guide wire type blood flow meter according to the present invention will now be described with reference to the thermodilution curve diagram of FIG. This is a value obtained by differentiating a curve portion corresponding to the temperature rising time, and the following formula [1] is obtained assuming that all the heat change amounts due to the injected cooling saline solution have passed through the temperature sensor of the blood flow meter. Corresponding to the blood flow velocity F (ml / min). F = (C ₁ Q ₁ / C ₀ T ₀ ) ΔT / ΔS [1] In the formula [1], C _{1 and} C ₀ respectively represent the specific heat of the cooled physiological saline and blood to be injected. , T _0, [Delta] T respectively represent the temperature of the blood, the temperature difference between the temperature T ₁ of the saline at the time of injection and blood _{(ΔT = T 0 -T 1)} , also Q ₁ is injected cooling saline In the volume (ml / min), ΔS is the time (min) from the time when the cooled physiological saline is injected and the temperature of the temperature sensor reaches the minimum value to the time when the temperature reaches the blood temperature T ₀ . Further, as described later, T ₁ is preferably in a range of at least 0 ≦ T ₁ ≦ 20 ° C., more preferably 4 to 10 ° C., in order to give a clear thermal change to the blood flow. In order to reduce the error, it is preferable to quickly inject the saline solution, and in the present invention, the injection was performed in 1 to 3 seconds in Examples described later.

In FIG. 4, the area of the curve corresponding to the rise time of the thermodilution curve corresponds to the blood flow Q (ml) flowing during the time ΔS shown in FIG. By integrating the corresponding parts, it is obtained as the following equation [2]. Q = Σ (C ₁ Q ₁ / C ₀ T ₀ ) dTdS (2) In the present invention, C ₁ and C ₀ can be regarded as C ₁ = C ₀ . From the above, based on the thermodilution curve diagram which was automatically recorded on the external device through the blood flow meter according to the present invention, the blood flow velocity F (ml / min) and the blood flow Q corresponding to the equations [1] and [2] were obtained.
(Ml) are obtained.

As described above, the blood flow meter according to the present invention comprises:
For example, when inserting an angiographic catheter or a catheter used for catheter treatment of various hearts into a blood vessel in the heart, a guide wire used for guiding the insertion is provided with a temperature sensing member for blood flow measurement. In particular, when a guide wire with a pressure sensor capable of measuring blood pressure, for which a patent application has already been filed by the present applicant, is used (see the conceptual diagram (A) in FIG. 1), the intracardiac of the tip portion inserted at the same time is used. Blood flow can be measured in synchronization with blood pressure, which is a remarkable feature of the guidewire type blood flow meter of the present invention.

In the case where the blood flow meter of the present invention has a guide wire type intracardiac electrocardiogram electrode for which a patent application has already been filed by the present applicant (see the conceptual diagram (B) of FIG. 1),
Since the tip platinum portion connected to this external measuring device by fine wiring is an electrode for electrocardiogram, accurate blood pressure measurement in the coronary artery in the heart which could not be obtained by conventional catheterization, furthermore Is synchronized with the intracardiac ECG,
The blood flow at the site is also measured, and these are features of the present invention that cannot be considered with a conventional blood flow meter.

Further, as described above, since the main body of the blood flow meter is a fine metal guide wire having excellent insertability and operability, it was impossible to perform measurement with a conventional catheter-type blood flow meter. Blood flow monitoring is possible even in a minute peripheral blood vessel of the heart such as a coronary artery, which is a remarkable feature of the present invention.

(Guide wire type blood flow meter) The guide wire type blood flow meter according to the present invention is a thermal flow meter, in which the blood flow meter is directly inserted into a minute blood vessel to sense the temperature at the tip. A temperature change of a blood flow thermally diluted with a predetermined amount of cooled physiological saline inserted by the member is sensed. Therefore, in order to measure the blood flow with the blood flow meter of the present invention, an injection operation of injecting a cooling saline solution into a blood vessel and thermally diluting the blood flow is required. In addition, since this injection method affects the measurement accuracy, the present invention improves this injection method, and measures the blood flow of microvessels by using an extremely small injection amount (thermodilution amount) and spot injection compared to the conventional method. Is made possible.

The improved injection method uses a fine guide wire as the main body of the blood flow meter, so that even a minute blood vessel to be measured by the present invention can be used as an injection tube for saline injection. Plastics microtubules with a diameter of 0.5 to 1.5 mm can be used. As a result, as described above, saline is directly injected into the target blood vessel, and spot injection is performed by devising the injection hole of the fine injection tube. It was made to.

As a result, the saline solution is spot-injected directly into the target blood vessel as described above. Therefore, as described in a reference example described later, the saline solution injected according to the conventional measurement method is used for the blood flow of cardiac activity. This is because it is not necessary to put the heat in the circulation, and a clear temperature change can be given to the blood flow even if the heat change amount (cooling saline amount) given to the blood flow as the thermodilution method is extremely reduced as compared with the conventional method. See the examples below).

Also, by injecting the microtubule for injection into a guidewire of the main body of the blood flowmeter and integrating the microtube for injection, the microtube as an injection tube can be inserted into a target blood vessel, and a spot of saline can be spotted. Make injection easier.

From the above, the injection amount of saline required for changing the temperature can be extremely reduced as compared with the conventional indirect catheter method, and all the injected heat change amounts can be measured by the blood flow meter. As a result, the blood flow measurement can be performed with improved measurement accuracy as compared with the conventional indirect method-thermodilution method, as will be apparent from the examples described later. I think it was.

Although the details are not clear, the blood flow meter of the present invention is a blood vessel insertion type guide wire having a small diameter, which is described in the following (1) to (4). The feature and the function and effect can be utilized to enable measurement of blood flow in microvessels. (1) The guidewire type blood flow meter is a stainless steel guidewire type having an inner diameter of 0.3 to 1.1 mm and a length of 10 to 30 including a rounded portion at the tip.
mm is a spiral-shaped tubular coil formed by densely winding a fine platinum wire, which is radiopaque. With this, the X-ray opaque part is used as a marker under X-ray fluoroscopy, and by rotating the tip of the guide wire left and right outside the body,
The movement is easily actuated by the guidewire in the blood vessel along the spiral shape of the guidewire, and can be advanced or changed direction. (2) In the lumen, there is a fine wiring connecting the external device and the temperature sensing member provided in the guide wire opening, and the opening of the temperature sensing member is adjacent to the X-ray opaque portion. Provided on a stainless steel sheath tube having a length of 2 to 30 mm which is welded by
It is provided at the rounded portion at the tip of the line opaque portion. As a result, the temperature sensing material of the blood flow meter is provided at a location that is very easy to contact the blood flow. (3) The cooled physiological saline injected to dilute the blood flow is 0.5 to 1.5 m in outer diameter connected to an external syringe.
m, inserted through a flexible microinjection tube 50-200 cm long. Also, from the rounded part at the tip of the injection tube,
At the 3 mm site, there are 1 to 4, preferably 2 to 3 injection holes along the tube in the lateral direction, and the injection hole site at the time of injection is inserted so as to be located in the microvessel. In the present invention, this fine tube may be inserted separately from the guide wire of the main body of the blood flow meter. However, since the diameter of the tube is fine, the tube is integrated with the guide wire, thereby reducing the complexity of insertion. Not only that, the saline can be accurately spot-injected into the microvessels. (4) The volume of the cooled physiological saline injected to give a clear temperature change to the blood flow by heat dilution may be 0.5 to 3 ml, preferably 1 to 1.5 ml. In the conventional Swan-Ganz catheter method, the injection volume is 5 ml for children and 10 m for adults.
In the present invention, the injection amount may be appropriately changed in the range of 5 to 10 ml in ordinary blood vessels other than the microvessels. Is used, and when the control of the measurement is microvessels, the injection amount is 0.5 to 3 as described above.
ml, preferably in the range of 1 to 1.5 ml. Also, the blood temperature of the human body is considered to be approximately 37 ° C., and physiological saline cooled at least about 10 ° C. lower than the blood temperature, preferably 0 to 20 ° C., and more preferably 4 to 10 ° C. is injected.

Therefore, the blood flow meter according to the present invention and the micro-injection tube used in conjunction with the blood flow meter can significantly reduce the amount of injection compared to the conventional method, and can quickly inject the injection in a spot-like manner. This is because the measurement accuracy of the thermodilution method was improved, which is consistent with the fact that the injection amount was reduced as in the use example described later.

The guide wire type blood flow meter according to the present invention is an extremely fine tubular wire as described above, and the guide wires of the main body are fixed to each other as shown in the conceptual diagram (A) of FIG. And an outer tube 2 made of stainless steel and having an extension 3 connected to an external measuring device and a sensor such as a temperature sensing member facing the opening, and an X-ray opaque tip 1 and the tip thereof. A rounded tip made of alloy is fixedly attached to the tip of 1.

Further, as is clear from the conceptual diagram (C) of FIG. 1, the opening for providing the temperature sensing member may be located at the rounded portion of the X-ray opaque tip portion 7, as exemplified in the drawing. Alternatively, the thermocouple 8 of the temperature sensing member can be fixedly mounted with resin. Therefore, it can be clearly understood from the drawings that the blood flow meter of the present invention is provided so that the temperature sensing member thereof is in sufficient contact with the blood flow in both types.

Now, the blood flow meter of the present invention will be described in more detail with reference to FIG.
m, and a tip 1 or 7 is a tubular coil densely packed with a platinum wire having an X-ray opaque length of 10 to 30 mm. In the guide wire with a pressure sensor shown in FIG. 1 (A), the tip 1 is welded to a stainless steel jacket tube 2 and the tinned silver-alloy alloy tip is welded. The pipe 2 is provided with a pressure sensor and a temperature sensing member.

The roundness of the X-ray opaque portion 1 or 7 is because the blood vessel wall is not damaged when the blood flow meter is inserted. In addition, since the insertion into the cardiovascular system is performed under fluoroscopy, this radiopaque portion is confirmed as a shadow (shadow picture), which not only facilitates the insertion of the above-mentioned catheter, but also facilitates blood flow. As a marker of the meter, a measurement site such as a blood flow can be clearly monitored.

The mantle tube 2 (sensor section) is made of stainless steel having a lumen having a length of 2 to 20 mm, preferably 3 to 10 mm, and a silicon chip 5 is provided in the inside of the mantle tube facing the opening. The semiconductor type pressure sensor or the temperature sensing member is fixed on the pedestal with epoxy resin exposing the sensing surface so as to contact the blood flow, and the terminals of the sensor etc. They are connected by fine wiring 6. Further, FIG. 1 (B) shows a platinum X-ray opaque portion of the distal end portion 1 where the outer surface of the guide wire is coated with a resin except for the distal end portion 1 and the metal surface is exposed. This is a guide wire type blood flow meter with an electrode for an electrocardiogram which is an electrode, and an internal fine wiring 6 ′ is welded to the distal end portion 1 and connected to an external device.

The length depends on the purpose of use,
In general, those having a length of 30 to 250 cm are appropriately used, and, if necessary, have a length of 1 to connect to an external measuring device at an end exposed outside the body when used.
A stainless steel extension tubular wire of 00 to 200 cm is detachably connected and used for easy extension.

(Blood Flow) The coronary artery, which is one of the minute blood vessels of the heart targeted by the blood flow meter of the present invention, is called a cardiac feeding tube that supplies oxygen and nutrients to the heart itself, and has a blood vessel diameter of 3 mm. Peripheral blood vessels are distributed so as to wrap around the heart from the surface, branching right and left from the base of the aorta. In such microvessels of the heart,
Recently, PT, a treatment for ischemia that replaces bypass surgery
In CA (percutaneous coronary angioplasty) and the like, a treatment for dilating a stenosis using a catheter with a balloon is being performed. In order to monitor a patient, at least blood pressure and an electrocardiogram are monitored. It is said that it is necessary to do.

The present inventor has proposed that a guide wire with a semiconductor type pressure sensor, which has already been applied for a patent, can be used for P-wires.
Although the blood pressure before and after the stenosis was successfully measured and monitored during the TCA operation, the blood flow was measured using the guidewire-type blood flow meter according to the present invention, so that the verification after the PTCA operation was confirmed. It is also expected that this will provide therapeutic information about the circulatory system, such as arrhythmias, myocardial disorders, atrial and ventricular hypertrophy, and pulmonary circulatory disorders.

Thus, the blood pressure changes in response to one beat of the diastole and the systole of the heart. In the aorta, the systolic pressure is usually 90 to 130 mmHg (diastolic pressure; 60 to 90 mmHg).
mmHg), the systolic pressure is 15
３５35 mmHg (diastolic pressure; 5 to 10 mmHg). In the right ventricle, the systolic pressure is 25 mmH
g or less (end diastolic pressure; 5-7 mmHg), and in the left ventricle, the systolic pressure is 80-120 mmHg (end diastolic pressure;
5 to 12 mmHg), and the blood circulates to generate a blood flow in response to one beat of the diastolic and systolic phases of the heart activity.

Therefore, it is understood that the measurement of blood flow by the guide wire type blood flow meter according to the present invention in synchronism with the blood pressure waveform and the electrocardiogram as a sign of heart activity is extremely significant for diagnosis or treatment of heart disease. Is done.

As a heart disease for which the measurement of blood flow is actually emphasized, there is an ischemic disease caused by stenosis or occlusion of a coronary artery.
Insufficient blood supply to tissues, high frequency among heart diseases, high mortality such as angina (exercise angina, atypical angina) and myocardial infarction, the most important heart disease And painless myocardial ischemia, heart failure, arrhythmia, valvular disease and the like.

Therefore, the use of the guide wire type blood flow meter of the present invention will be described in more detail. For example, in coronary angiography which is indispensable for diagnosis of angina pectoris and myocardial infarction, the origin of the left and right coronary arteries is determined. The method of taking an image of the coronary artery on a cine film by injecting a contrast agent through a catheter from the part is taken, and before injecting the contrast agent, the blood flow meter of the present invention is used as a so-called guide wire, After the contrast medium is injected, it is inserted again to be used suitably for measuring the blood pressure at the target site and / or measuring the blood flow at the insertion site.

In percutaneous coronary angioplasty (PTCA), which is widely used as a treatment for ischemic heart disease, a guidewire-type intracardiac electrode is passed through an occluded coronary artery, and a balloon catheter is occluded. It is preferably used for mechanically expanding the occluded blood vessel by inflating the balloon by inserting it into the public part, re-establishing blood flow, and quickly measuring pressure or blood flow before and after the stenosis.

Further, as a method of treating a cardiac catheter, the method is suitably used when a catheter is inserted from an artery or a vein to measure the pressure and blood flow in the atrium and the ventricle.

As described above, PTCA, PTA
Conducted as a prior diagnosis of catheter treatment such as
In clinical examination such as S, we monitor electrocardiogram,
At the same time, it is suitably used not only for measuring blood flow in conjunction with blood pressure check, but also for microvessels other than the heart, such as blood vessels in the brain.

The present invention is further described in the following examples.

(Temperature Sensing Member) Examples of the temperature sensing member provided in the guide wire type blood flow meter according to the present invention include a thermocouple, a temperature measuring resistor, a thermistor, and a thin film temperature sensor described below. Depending on the type of the blood flow meter of the present invention, preferably, it can be appropriately selected from a thermocouple, a thermistor, and a thin film temperature sensor.

As a thermocouple, K-type allomer-chromel (AC) is an alloy containing Ni as a main component and has good corrosion resistance at low temperatures and good temperature linearity.

As a temperature measuring resistor, the resistance value changes only with the temperature, and the temperature and the resistance value have a good linearity. For example, a resistor of 100 Ω at 0 ° C. of platinum temperature measuring resistor has a resistance per 1 ° C. The value change is about 0.4Ω, and when a current of 1 mA is passed through it, the output changes by 400 μV, the sensitivity is high, the electromotive force per 40 ° C./° C. of the K-type thermocouple is large, and the temperature coefficient of the resistance is large. JIS has been adopted as a resistance thermometer.

The thermistor is a semiconductor temperature-sensitive resistance element, which is a normal semiconductor having a negative temperature coefficient of resistance (NTC) whose resistance value decreases with temperature. Since the electric resistance is large, the lead wire can be lengthened, the temperature coefficient of the resistance is increased by one digit, and a compensating lead wire and a reference point are not required unlike a thermocouple. As described above, since the resistance is as large as kΩ, it can be easily combined with an electronic circuit, and is most widely used for measurement as a low to medium temperature temperature sensor of −50 to 350 ° C., and is standardized by JIS as an NTC thermistor.

Further, in addition to the above three types, SiC, Zr
There are thin-film temperature sensors such as N and Pt, and ZrN is a low-temperature temperature sensor, which is suitable as a high-sensitivity sensor near room temperature. The SiC and Pt thin-film sensors have the weak points of the platinum temperature sensor. Reinforcement of mechanical strength and downsizing can be achieved. Further, as an IC temperature sensor, a temperature change of −2 mV / ° C. of the voltage between the base and the emitter of the transistor is used to measure the temperature with an accuracy of ± 0 and 1 ° C. in the range of −50 to 150 ° C. .

(Semiconductor Pressure Sensor, Temperature Compensation Circuit) The semiconductor pressure sensor mounted on the guide wire according to the present invention may be a diaphragm type capacitance type, a semiconductor diffusion resistance type, or a semiconductor capacitance type. , An electromagnetic induction type, a piezoelectric element type, a force balance type, a strain gauge type, and a thin film strain sensor type. A piezoresistive pressure sensor with a Wheatstone bridge on the base to fix the sensor amplifies the measured electric resistance by a semiconductor sensor that converts the pressure change to electric resistance, and the atmospheric pressure sensor inside the main unit amplifies the measured electric resistance The blood pressure is measured by correcting and converting the voltage. That is, when an excitation voltage is supplied to the Wheatstone bridge circuit, the resistance is changed by receiving pressure of the silicon membrane.
On the other hand, a change is received by a temperature resistance element provided in the temperature compensation circuit, and the resistance difference between the two is converted into a voltage and converted into a pressure. Further, the temperature of the blood flow is sensed by the temperature resistance element.

(Fine Wiring) As the conductive fine wiring connected to the temperature sensing member and the semiconductor sensor, a micro cable in which ordinary fine conductive wires are covered with a fluororesin is preferably used. In the present invention, a flexible printed wiring board can be appropriately used in addition to a normal conductive wire. That is, copper foil on a film such as a polyester film, a fluororesin film, a polyimide film, a polyester film, a polyvinyl chloride film,
Or a flexible printed wiring material with a ribbon-shaped copper core attached to it, and furthermore a flexible flat cable, a flexible printed circuit, a low loss printed board, a through-hole plated printed wiring board, a non-through-hole printed printed wiring board, and a flexible printed wiring Microlithography using a photoresist on a plate or a silicon substrate can be used.

The guide wire of the main body of the blood flow meter of the present invention has no problem of corrosion, toxicity, elution, etc. since its main material is corrosion-resistant stainless steel or platinum. From the viewpoint of safety, special consideration is given to dissolution, toxicity, corrosion, etc. of the material of the member, and a resin-coated material is used to improve insertability.

(Embodiment) The blood flow measurement is performed independently by the guide wire type blood flow meter or the guide wire type blood flow meter with a pressure sensor and / or the electrode for an intracardiac electrocardiogram used in the present invention, or the blood pressure and / or blood pressure is measured. The measurement of the blood flow velocity in synchronization with the electrocardiogram measurement will be described below with reference to FIGS.

(Usage Example 1: Guidewire blood flowmeter with pressure sensor) In the case of coronary artery stenosis, first, a guidewire blood flowmeter with a semiconductor pressure sensor was used.
The site where the blood vessel is narrowed is passed through the guiding catheter to the site where the blood vessel is narrowed.
The CA balloon was inflated, and the blood pressure before and after the stenosis before and after the treatment was measured. FIG. 5A shows a pressure waveform before balloon dilation before a stenosis, and FIG. 5B shows a pressure waveform after balloon dilation. A PG curve in the figure is obtained by a guide wire type blood flow meter with a pressure sensor according to the present invention. In the blood pressure wave, the GC curve is a pressure waveform by a guiding catheter for comparison. In FIG. 6, after measuring the blood pressure just before the stenosis,
The blood flow meter was advanced over the stenosis, and the pressure waveform at the stenosis tip during PTCA operation was measured. The curve A in the figure is the pressure waveform before the stenosis, and the curve B is the pressure waveform before the stenosis during the PTCA operation.

When the two waveforms are compared, the effect of dilation of the stenosis is confirmed from the waveform after the PTCA operation.
A preliminary blood flow ratio (Fract) obtained as a ratio of a and Pd
ionic Flow Reserve; FFR = Pd
/ Pa), which is also characteristic of the blood flow meter of the present invention being a guide wire type with a pressure sensor.

(Usage Example 2: Guidewire-type blood flowmeter with pressure sensor) A measurement example in which a guidewire-type blood flowmeter with a pressure sensor was used and saline was injected using a catheter as a fine tube was shown in FIG. This will be described with reference to FIGS. As described above, in the percutaneous coronary angioplasty (PTCA), which is widely used in place of bypass surgery, using the blood flow meter of the present invention, a guidewire type blood flow with a semiconductor type pressure sensor is applied to an occluded coronary artery. Through the meter, along with this insert the balloon catheter into the obturator,
In the method of mechanically expanding the occluded blood vessel by inflating the balloon and measuring the blood flow again, after quickly measuring the pressure before and after the stenosis, the blood flow is measured in synchronization with this. is there.

In FIG. 2, a guidewire type blood flow meter 16 according to the present invention is inserted along a coronary artery 14 branched from an aorta 13. The hatched portion 17 of the coronary artery 14
Is a coronary artery in which an occluded diseased part such as 18 is reopened by PTCA operation, and the main body of the guide wire type blood flow meter is equipped with a semiconductor type pressure sensor as described above. A clearly improved blood pressure waveform before and after was measured, and the postoperative blood flow was measured in synchronization with this. That is, the distal end portion (temperature sensing portion) of the blood flow meter of the present application is inserted beyond the shaded portion 17, and then the catheter 11 with the side port 12 is inserted through the guide wire 16 which is a blood flow meter, and the distal end opening is closed as shown in FIG. Is inserted so as to reach the coronary artery entrance 15.

When inserting the catheter, the blood flow surface in the catheter must be at least
Higher than Next, in FIG. 2, a syringe for injecting a cooling saline is connected to the side port 12 at the same time, and this syringe is a special syringe, and a physiological saline always cooled to a constant temperature is circulated. The temperature of the circulated and cooled saline solution is measured with a thermometer at a supply port to the syringe. When the saline solution is injected, the circulatory system is cocked, and the main port 11 of the catheter is used as needed. Click also to quickly inject a predetermined amount of cooling saline.

As a cooling saline, 3.6 ml of physiological saline at 5.4 ° C. is injected in about 2 seconds, and at the same time, the temperature sensed by a temperature sensor at the tip of the guide wire 16 by an external measuring instrument is injected. The blood flow temperature above the infused sensing part is the normal blood temperature T ₀ (3
7 ° C) and flows to the sensing part. The temperature change until the blood flow temperature measured by the sensing unit again becomes the normal blood temperature T ₀ was recorded over time, and a thermodilution curve diagram (see FIG. 4) was obtained. In addition, this measurement was performed twice under the same conditions, and almost the same thermodilution curve diagram could be obtained.

As a result, the guide wire type intracardiac blood flow meter according to the present invention is also used as a guide wire for guiding the insertion of a catheter, and the guide wire is equipped with a semiconductor pressure sensor for measuring blood pressure. In this case, insertion guidance, blood pressure measurement, blood flow measurement, and other functions are performed, and the blood flow after PTCA operation is measured by this blood flow meter. It can be verified. Further, when the blood flow meter is provided with a guide wire type intracardiac electrocardiogram electrode (see FIG. 1B), the blood flow measurement (blood flow velocity, blood flow rate) at the insertion site, which is the object of the present invention, is performed. This can be performed in synchronization with the electrocardiogram waveform.

(Usage Example 3: Guidewire type blood flow meter with pressure sensor) Using a guidewire type blood flow meter with a pressure sensor, a flexible fine injection tube 19 with an outer diameter of 1 mm was used for injecting cooling saline. To be inserted over the shaded portion 17 of the coronary artery 14, which is the same vascular site as in Use Example 2, and
An example in which the blood flow flowing normally in synchronization with the clearly improved blood pressure before and after the operation A will be described with reference to FIG.

In FIG. 3, the distal end (temperature sensing portion) of the guide wire type blood flow meter 16 according to the present invention is inserted along the coronary artery 14 branched from the aorta 13 beyond the hatched portion 17 shown in FIG. Then, the catheter 11 with the side port 12 is inserted through the guide wire type blood flow meter 16, and the distal end port is inserted so as to reach the coronary artery entrance 15 in FIG.

When inserting the catheter, the blood flow surface in the catheter must be at least the side port 12 '.
Higher than Next, in FIG. 3, a fine injection tube 19 to which the cooling water injection syringe 20 is connected is inserted from the side port 12 at the same time, and the injection hole 21 at the distal end thereof passes over the coronary artery entrance 15 as shown in FIG. Insert slightly into the coronary artery.

At the time of injection, 1.6 ml of 4.8 ° C. physiological saline was injected in about 1.5 seconds from three injection holes provided laterally at a position 2-3 mm from the tip. At the same time, the temperature sensed by the temperature sensing unit at the distal end of the guide wire 16 by an external measuring instrument causes the blood flow temperature to drop below the normal blood temperature T ₀ (37 ° C.) due to the injected physiological saline, and the sensing unit The temperature change until the blood flow temperature measured in step (1) returns to the normal blood temperature T ₀ again was recorded over time to obtain a thermodilution curve diagram. In addition, this measurement was performed twice under the same conditions, and almost the same thermodilution curve diagram could be obtained.

(Usage Example 4: Guide wire type blood flow meter) A guide wire type blood flow meter shown in FIG. 1 (C) as a blood flow meter, wherein an allomer-chromel K-type thermocouple is attached to a temperature sensing member. ing. This blood flow meter was inserted into a normal coronary artery, and then 3.2 ml and 3.6 ml of physiological saline at 6 ° C. were injected in 2 seconds and 3 seconds, respectively, as in Example 1. FIG. A thermodilution curve diagram was obtained as shown.

Reference Example 1 Conventional Sawangantz Indirect Method For example, to measure the blood flow in the pulmonary artery in the heart by the thermodilution catheter method, a balloon is provided at the distal end of the catheter, and a balloon is provided behind the balloon. A thermistor is attached, a catheter is inserted from the right hand vein, and the tip of the catheter enters the right atrium of the heart. When the balloon is inflated in the right atrium, the balloon enters the pulmonary artery from the right ventricle due to the blood flow, where the balloon is contracted and the catheter is fixed, and the temperature change at the tip of the pulmonary artery is measured as follows. Measure blood flow at

That is, since the injection hole on the side of the catheter approximately 30 cm behind the balloon is located in the right ventricle, when 10 ml of saline solution cooled to, for example, 4 ° C. is injected, the blood is ejected into the right ventricle and blood in the right ventricle is injected. And the blood flow that has been thermodiluted and the temperature has dropped out of the right ventricle at the next heartbeat, and the cooled blood flow is sensed by the thermistor, and a thermodilution curve diagram similar to FIG. 4 is obtained, From this, the blood flow is determined. In such a conventional catheter method, a large amount of heat change is required, the injection is complicated, the blood flow path is long, and an error easily occurs, and the blood flow cannot be measured accurately. Moreover, because of such an injection method and a measurement method, measurement on a fine blood vessel as in the present invention is impossible.

[0080]

According to the present invention, a clinical test such as EPS can be performed by a metal guide wire type blood flow meter or a guide wire type blood flow meter with a pressure sensor and / or an electrode for electrocardiogram according to the present invention.
In catheter treatments such as TA (percutaneous angioplasty) and PTCA (percutaneous coronary angioplasty), the blood flow meter serves as a guide wire and is essential for these examinations and treatments. With a guide wire type or semiconductor type pressure sensor capable of measuring blood pressure at an inserted site and / or measuring an electrocardiogram at an intracardiac site close to the heart surface and synchronizing with the measurement, and / or A guidewire-type blood flowmeter with an electrocardiogram electrode could be provided.

The guide wire type blood flow meter according to the present invention
Because the guide wire of the main body of the blood flow meter is fine, and the insertion and operability are extremely excellent, blood that can measure blood flow in micro blood vessels such as the coronary artery, which was impossible with the conventional thermodilution method, is not possible. It is a flow meter.

Further, by examining the method of injecting physiological saline to be combined with the blood flow meter of the present invention, the injection amount of physiological saline required for thermodilution is significantly reduced as compared with the conventional thermodilution catheter method. As a result, the injection of saline solution was completed in a spot-like manner and instantaneously, and a stable thermodilution curve diagram with less measurement fluctuation was obtained. Furthermore,
As a verification of the PTCA treatment, the blood flow may be directly measured instead of the conventional FFR blood flow reserve ratio.

[Brief description of the drawings]

1A is a conceptual diagram of a guide wire type blood flow meter with a pressure sensor of the present invention, FIG. 1B is a conceptual diagram of a guide wire type blood flow meter with an intracardiac electrogram electrode, and FIG. () Shows a conceptual diagram of a guide wire type blood flow meter in which the temperature sensing member is a thermocouple.

FIG. 2 shows a guidewire type blood flow meter inserted into a coronary artery and a catheter with side ports for infusion of chilled saline.

FIG. 3 shows a usage example of a plastic injection tube for injecting a cooled physiological saline used in the present invention.

FIG. 4 shows a thermodilution curve after stenosis at the right coronary artery site after PTCA operation obtained by the guidewire-type blood flow meter of the present invention.

FIG. 5 shows pressure waveforms before and after a stenosis portion by a guide wire type blood flow meter with a pressure sensor of the present invention before and after PTCA operation.

FIG. 6 shows pressure waveforms before and after a stenosis by a guidewire type blood flow meter with a pressure sensor of the present invention during PTCA operation.

[Explanation of symbols]

 1, 7 X-ray opaque tip (spiral wire made of platinum) 2 Stainless steel sheath (sensor part) 3 Extension 4 Opening 5 Silicon chip pedestal 6, 6 ', 9 Fine wiring 8 Thermocouple 10 Catheter 11 Main Port 12 Side port 13 Aorta 14 Coronary artery 15 Coronary artery entrance 16 Guide wire type blood flow meter 17 PTCA treated stenosis 19 Plastic microtubule 20 Syringe 21 Injection hole

Claims (13)

[Claims] 1. A stainless steel guide wire having an outer diameter of 0.3 to 1.1 mm and having a lumen, and a length of 10 to 30 mm including a rounded portion at the end of which is made of a platinum fine wire which is radiopaque. Helical tubular coil formed by tightly winding a wire inside the guide wire, the fine wire connecting the external device and the temperature sensing member provided in the guide wire opening is internally provided in the lumen of the guide wire, and The temperature sensing unit senses the temperature of the blood flow that has been thermodiluted by the cooling saline injected through the flexible tubule, and the blood flow velocity is calculated from the temperature change curve diagram of the blood flow recorded on an external device. And a blood flow meter for measuring a blood flow. 2. In the above guidewire type blood flow meter,
2. The guidewire type blood flow meter according to claim 1, wherein an injection hole at a distal end of a flexible thin tube connected to an external syringe is inserted into the microvessel, and a predetermined amount of cooling saline is injected. . 3. The flexible thin tube is a plastic tube having an outer diameter of 0.3 to 1.5 mm, and the injection holes 1 to 4 are disposed laterally at a position 1 to 3 mm from a round portion at the tip of the plastic tube. The guidewire type blood flow meter according to claim 1 or 2, wherein the guidewire type blood flowmeter includes: 4. The guide wire type blood flow meter according to claim 3, wherein said plastic tube is resin-bonded to a guide wire of a blood flow meter main body. 5. The injection amount of the saline is 0.5 to 3 m.
The guidewire-type blood flow meter according to any one of claims 1 to 3, wherein l is 1. 6. The above blood flow velocity and blood flow rate are represented by the following equations: F = (C ₁ Q ₁ / C ₀ T ₀ ) ΔT / ΔS [1] C ₁ , C ₀ ; Specific heat of water and blood, T ₀ , ΔT; temperature of blood, temperature difference between blood and physiological saline T ₁ (ΔT = T ₀ −T ₁ ), where 0 ≦ T ₁ ≦ 20 ° C. ), Q ₁ : Injection amount of cooling saline (ml / min), ΔS: Time (min) from when cooling saline is injected and the temperature of the temperature sensing unit reaches the blood temperature T ₀ , And Q = Σ (C ₁ Q ₁ / C ₀ T ₀ ) dTdS... [2] Blood flow velocity F (ml / min) and blood flow Q
The guidewire type blood flow meter according to claim 1, wherein the blood flow is measured as (ml). 7. The method according to claim 1, wherein the opening is provided in a rounded portion at the tip of the guide wire, and an allomer-chromel-type thermocouple of the temperature sensing member is locked to the rounded portion with epoxy resin. The guidewire-type blood flow meter according to any one of 1 to 6. 8. The guide wire type blood flow meter according to claim 1, wherein the temperature sensing member is a platinum resistance temperature detector. 9. The stainless steel mantle tube having an opening having a length of 2 to 20 mm and having a lumen, the mantle tube is welded adjacent to the radiopaque tubular coil, and a temperature sensor is provided. 7. The member according to claim 1, wherein the member is provided as a pedestal in a lumen facing the opening of the mantle tube so as to be exposed so as to be in contact with the blood flow on the surface of the silicon chip locked with epoxy resin. The guidewire type blood flow meter according to any one of the above. 10. The temperature sensor according to claim 9, wherein said temperature sensing member is provided as a pair of temperature compensation circuits in a Whiston bridge circuit of the semiconductor pressure sensor for measuring blood pressure.
The guidewire-type blood flow meter as described. 11. The guide wire type blood flow meter according to claim 7, wherein an outer portion of the guide wire main body is covered with a Teflon resin except for an X-ray opaque portion at a tip end, and the guide is provided. A guide wire type blood flow meter, wherein a fine wire connecting an external measuring device and an X-ray opaque portion is present inside the wire lumen, and the X-ray opaque portion is an electrode for an intracardiac electrogram. 12. The guide wire type blood flow meter according to claim 9, wherein said temperature sensing member is a Pt thin film temperature sensor. 13. The guide wire type blood flow meter according to claim 9, wherein the temperature sensing member is a semiconductor temperature-sensitive resistance element.