JP7673674B2 - Puncture tool and catheter assembly - Google Patents

Description

The present invention relates to a puncture device and a catheter assembly including the puncture device.

Conventionally, in medical situations, such as central venous puncture to insert a catheter into a vein to administer fluid infusion, puncture is performed on a patient's internal tissue. Such puncture (puncture of a patient's internal tissue) is usually performed while visually observing an ultrasonic tomographic image of the patient's internal tissue obtained by an ultrasound diagnostic device.

Patent Document 1 discloses a technology that includes a diffusion-type semiconductor pressure sensor that is sensitive to the pressure of the blood flow when the needle tip punctures a blood vessel, and detects and notifies the user that the blood vessel has been punctured by the needle. Then, upon receiving the notification that the blood vessel has been punctured by the needle, the operator presses the drive button of the syringe motor to start the injection, and a fixed amount of medicinal liquid or blood is automatically injected.

JP 2006-175191 A

The technology of Patent Document 1 mentioned above makes it possible to recognize that a blood vessel has been punctured without visually checking the backflow of blood (flashback) caused by the puncture. However, it was not possible to know whether the blood vessel into which the needle had been inserted was a vein or an artery until the needle had been inserted (i.e., only after the needle had been inserted). This made it difficult to prevent accidentally puncturing a vein and an artery (mispuncture).

The present invention has been made to solve the above problems, and aims to provide a puncture device that can determine whether a blood vessel is a vein or an artery before puncturing the blood vessel (i.e., without puncturing the blood vessel), and can prevent puncturing a vein and an artery by mistake (mispuncture), and a catheter assembly equipped with the puncture device.

The puncture tool according to the present invention is characterized by comprising a hollow puncture needle that is inserted into a blood vessel, a detection unit that can protrude forward from the tip of the puncture needle and detects the pulsation of the blood vessel, and a determination unit that determines whether the blood vessel is a vein or an artery based on the pulsation of the blood vessel detected by the detection unit.

The catheter assembly according to the present invention is characterized by comprising the above-mentioned puncture tool and a catheter that is inscribed on the outer circumferential surface of the puncture tool and stores the puncture tool so that it can slide in the axial direction.

According to the puncture tool or catheter assembly of the present invention, for example, before the puncture needle is inserted into the blood vessel (prior to puncturing), the pulsation of the blood vessel can be detected by protruding the detection unit forward from the tip of the puncture needle. Then, based on the detected pulsation of the blood vessel, it can be determined whether the blood vessel is a vein or an artery. Therefore, before the puncture needle is inserted into the blood vessel, it can be determined whether the blood vessel is a vein or an artery. As a result, it is possible to prevent the puncture of a vein and an artery by mistake (mispuncture).

According to the present invention, it is possible to determine whether a blood vessel is a vein or an artery before puncturing the blood vessel (i.e., without puncturing the blood vessel), and it is possible to prevent accidentally puncturing a vein instead of an artery (mispuncture).

1 is a perspective view showing a puncture device according to an embodiment and a catheter assembly including the puncture device. 5A and 5B are schematic diagrams showing the configuration of a detection section constituting the puncture tool according to the embodiment. 13 is a schematic diagram showing another example of a detection section constituting the puncture tool according to the embodiment. FIG. 1A and 1B are diagrams showing a state of a puncture tool according to an embodiment before and after retraction, respectively; 6A and 6B are diagrams showing an example of a notification section constituting the puncture tool according to the embodiment; FIG. 13 is a diagram showing the impedance characteristics (peak shift) of the sensor before and after contact with the blood vessel. FIG. 1 is a diagram showing the amplitude of pulsation (pressure) of a vein and an artery. FIG. 1 is a diagram (part 1) showing a puncture method (puncture procedure) using a catheter assembly according to an embodiment. FIG. 2 is a diagram (part 2) showing a puncture method (puncture procedure) using the catheter assembly according to the embodiment. FIG. 3 is a diagram (part 3) showing a puncture method (puncture procedure) using the catheter assembly according to the embodiment. FIG. 4 is a diagram (part 4) showing a puncture method (puncture procedure) using the catheter assembly according to the embodiment. FIG. 5 is a diagram (part 5) showing a puncture method (puncture procedure) using the catheter assembly according to the embodiment.

Below, a preferred embodiment of the present invention will be described in detail with reference to the drawings. Note that in the drawings, the same reference numerals will be used for the same or corresponding parts. In addition, in each drawing, the same elements will be given the same reference numerals, and duplicate explanations will be omitted.

First, the configuration of the puncture tool 2 according to the embodiment and the catheter assembly 1 including the puncture tool 2 will be described with reference to Figures 1-2 and 4-5. Figure 1 is a perspective view showing the puncture tool 2 and the catheter assembly 1 including the puncture tool 2. Note that Figure 1 shows a state in which the puncture needle 21 and the puncture needle hub 22 are pulled backwards. Figure 2 is a schematic diagram showing the configuration of the detection unit 23 that constitutes the puncture tool 2. Figure 4 is a diagram showing the respective states of the puncture tool 2 (a) before retraction and (b) after retraction. Figure 5 is a diagram showing an example of a notification unit 25 that constitutes the puncture tool 2.

The catheter assembly 1, which is equipped with a puncture tool 2, punctures internal body tissue (skin, blood vessels, etc.) and inserts a catheter 3 into a vein, for example, to administer fluids, etc.

In particular, the catheter assembly 1 equipped with the puncture tool 2 can determine whether a blood vessel is a vein or an artery before puncturing the blood vessel (i.e., without puncturing the blood vessel), and has the function of preventing the mistaken puncture of a vein and an artery (mispuncture).

Therefore, the catheter assembly 1 is composed of a puncture tool 2 and a catheter 3 that is inscribed on the outer circumferential surface of the puncture tool 2 and stores the puncture tool 2 so that it can slide (move relatively) in the axial direction. Each component will be described in detail below.

The puncture tool 2 mainly comprises a hollow puncture needle (inner needle) 21 that is inserted into the blood vessel, a detection unit 23 that can protrude axially forward from the tip of the puncture needle 21 (can move forward and backward freely) and detects the pulsation of the blood vessel, a determination unit 24 that determines whether the blood vessel is a vein or an artery based on the pulsation of the blood vessel detected by the detection unit 23, and a notification unit 25 that notifies the result of the determination.

The puncture needle 21 has a sharp tip, and the tip that penetrates and protrudes through the catheter needle (outer needle) 31 is inserted into the skin of a patient, etc., to guide the catheter needle 31. The base end of the puncture needle 21 is held by the puncture needle hub (inner needle hub) 22. The puncture needle hub 22 is formed in a stepped cylindrical shape with a thin, tapered tip portion, and is disposed within the hollow portion of the catheter hub (outer needle hub) 32 so as to be movable relative to the patient in the axial direction.

The detection unit 23 is provided inside (inner side) the hollow puncture needle 21 so that it can freely advance and retreat in the axial direction (i.e., it can move relative to the puncture needle 21). This reduces the effect of pressure from body tissue when puncturing, and allows for more accurate detection of blood vessel pulsation. In addition, since sensing can be performed at the needle tip, which is closer to the blood vessel, pulsation can be detected with high sensitivity. If the detection unit 23 can protrude even slightly forward from the puncture needle 21, it is possible to prevent puncturing a vein and an artery by mistake.

More specifically, the detection unit 23 is configured to have a probe 231 that is provided inside the hollow puncture needle 21 so that it can move forward and backward in the axial direction (relatively movable), a probe hub 232 that holds the probe 231, and a sensor 233 that is disposed on the rear end side of the probe 231 and detects the pulsation of the blood vessel transmitted via the probe 231.

The probe 231 is formed in the shape of a long, thin rod with a generally flat tip. The probe 231 is preferably formed from, for example, a metal such as stainless steel or a hard synthetic resin. In this case, the probe 231 can be moved and brought into direct contact with a blood vessel to detect the pulsation of the blood vessel, thereby enabling detection of the pulsation of the blood vessel with higher sensitivity.

The probe hub 232 holds the probe 231 at its base end. The probe hub 232 is formed in a stepped cylindrical shape that includes a reduced diameter portion at the tip end and an expanded diameter portion connected to the reduced diameter portion. By rotating the probe hub 232 in the circumferential direction, the probe 231 can be advanced or retracted in the axial direction.

The sensor 233 is disposed, for example, at the rear end of the probe 231 within the probe hub 232 (see FIG. 2). The sensor 233 detects, for example, pressure due to pulsation of a blood vessel. The sensor 233 is made of, for example, a piezoelectric body (piezoelectric element) that outputs an electric signal (for example, voltage) corresponding to the pressure due to pulsation of a blood vessel. By using a piezoelectric body as the sensor 233, the sensor 233 can be made smaller and can be housed in the thin probe hub 232. In addition, the method of detecting pressure only requires touching the blood vessel and does not depend on the way of application, so there is little measurement error due to individual differences, and even users with relatively low technical proficiency can accurately detect. On the other hand, the method of detecting pressure cannot detect pressure when it is separated from the blood vessel wall, so the possibility of mistakenly determining that it is a vein can be reduced.

Figure 6 shows the impedance characteristics (peak shift) of the sensor (piezoelectric body) 233 before and after contact with the blood vessel. The horizontal axis of Figure 6 is frequency (Hz), and the vertical axis is impedance (Ω) of the sensor (piezoelectric body) 233. As shown in Figure 6, after contact with the blood vessel, the impedance peak value decreases and the impedance peak frequency shifts (peak shift) to a higher frequency side compared to before contact with the blood vessel. Therefore, by detecting the impedance peak shift or impedance difference of the sensor (piezoelectric body) 233, it is possible to determine whether the probe 231 has contacted the blood vessel. The electrical signal detected by the sensor 233 is output to the determination unit 24.

The determination unit 24 determines whether the blood vessel is a vein or an artery, for example, based on the magnitude of the amplitude (= pressure) of the blood vessel pulsation detected by the sensor 233. Here, the amplitude of the pulsation of the vein and the artery is shown in FIG. 7. The horizontal axis of FIG. 7 is time, and the vertical axis is the amplitude of the pulsation. As shown in FIG. 7, the amplitude of the artery is greater than the amplitude of the vein. Therefore, the determination unit 24 determines that the blood vessel in contact is a vein when the detection value of the sensor 233 is less than a predetermined threshold value set between the minimum value of the artery amplitude and the maximum value of the vein amplitude, for example. On the other hand, the determination unit 24 determines that the blood vessel in contact is an artery when the detection value of the sensor 233 is equal to or greater than the predetermined threshold value. Note that the greater the pulsation, the greater the peak shift amount of the impedance of the sensor (piezoelectric body) 233 described above. Therefore, the peak shift amount of the artery is greater than that of the vein. Therefore, whether the blood vessel is an artery or a vein may be determined based on the peak shift amount of the impedance. In addition, determining whether it is an artery or a vein includes not only direct determination, but also indirect determination, such as determining whether the amplitude of the detected signal is above/below a threshold value, or determining whether the period (peak shift amount) of the detected signal is above/below a threshold value.

Furthermore, when the same judgment result (judgment result of whether it is a vein or an artery) is obtained a predetermined number of times or more (for example, two or more times in a row), the judgment unit 24 confirms the judgment result. In this way, the influence of pulse-like noise, etc. can be eliminated, and a more accurate judgment can be made (misjudgment can be prevented). The judgment unit 24 may be configured (configured as software) by a CPU that executes calculations and a memory that stores programs and data, or may be configured (configured as hardware) by a comparator consisting of an operational amplifier, etc. The judgment result by the judgment unit 24 is output to the notification unit 25.

The notification unit 25 notifies the user of the determination result as to whether the blood vessel is a vein or an artery. As shown in FIG. 5, the notification unit 25 is configured to have, for example, a red LED 25R indicating that the blood vessel is an artery, and a green LED 25G indicating that the blood vessel is a vein. When the blood vessel is determined to be an artery, the notification unit 25 turns on the red LED 25R. On the other hand, when the blood vessel is determined to be a vein, the notification unit 25 turns on the green LED 25G. Note that instead of light emission (LED), the determination result may be notified by sound, text display, or the like. In this way, the user can accurately recognize whether the blood vessel in contact with the catheter assembly 1 is an artery or a vein.

The catheter 3 is mainly composed of a catheter needle (outer needle) 31, a catheter hub (outer needle hub) 32 that holds the catheter needle 31, and an infusion tube 34. The catheter 3 is inscribed on the outer circumferential surface of the puncture tool 2, and houses the puncture tool 2 so that it can slide (move relatively) in the axial direction.

The catheter needle 31 is a flexible, thin-diameter tubular member that is formed to a length that allows it to be introduced and left in the patient's body. An inner cavity is formed inside the catheter needle 31 along the axial direction. This inner cavity has an inner diameter that allows the puncture needle 21 to be inserted therethrough. A resin material, particularly a soft resin material, is suitable as a constituent material of the catheter needle 31.

In the initial state (before retraction), the puncture needle (inner needle) 21 is placed inside the catheter needle (outer needle) 31 with its tip protruding. Also, as described above, the exploration needle 231 is placed inside the puncture needle 21.

The catheter hub 32 is a stepped hollow cylindrical member that holds the base end of the catheter needle 31, and is composed of a tapered portion 32a formed in a tapered shape and a cylindrical portion 32b formed in a cylindrical shape. The catheter hub 32 is preferably composed of a transparent resin so that all or part of the inside can be visually observed.

As shown in FIG. 4B, the catheter hub 32 is configured so that the exploration needle 231 and the puncture needle 21 (puncture tool 2) can be retracted (pulled back) and stored. That is, the catheter hub 32 functions as the retraction section described in the claims. FIG. 4B is a diagram showing the state in which the puncture needle 21 and the exploration needle 231 have been retracted into the catheter hub 32. In this way, by retracting the puncture needle 21 and the exploration needle 231 into the catheter hub 32, it is possible to prevent the flow of medicinal fluid or blood from being obstructed by the exploration needle 231, etc., when injecting medicinal fluid, collecting blood, etc.

As shown in FIG. 12, the infusion tube 34 passes through the inside (hollow portion) of the probe hub 232 and is liquid-tightly connected to the catheter hub 32 (cylindrical portion 32b). Thus, for example, a medicinal liquid can be supplied to the patient's vein through the catheter 3 including the infusion tube 34.

Next, a method of using the catheter assembly 1 (the procedure for inserting the catheter assembly 1 into a patient's vein) will be described with reference to Figures 8 to 12. Figures 8 to 12 are diagrams (parts 1 to 5) showing a puncture method (puncture procedure) using the catheter assembly 1.

As shown in FIG. 8, a user such as a doctor first punctures the patient's skin with the catheter assembly 1 (puncture tool 2, catheter 3) while visually viewing an ultrasonic tomographic image of the patient's internal tissue, and advances the tip of the catheter assembly 1 to just before the blood vessel. At this time, the puncture needle 21 is placed inside the catheter needle 31, stacked with its tip protruding. In addition, the exploration needle 231 is placed inside the puncture needle 21 (with its tip not protruding).

Next, as shown in FIG. 9, a user such as a doctor rotates (rotates) the probe hub 232 around its axis, thereby releasing the engagement between the probe 231 and the probe hub 232 that holds the probe 231 and the puncture needle hub 22 that holds the puncture needle 21, and causing the probe 231 to protrude forward beyond the tip of the puncture needle 21.

Next, as shown in FIG. 10, a user such as a doctor protrudes the probe 231 and places it against the blood vessel wall to determine whether the blood vessel is a vein or an artery. Note that the method for determining whether the blood vessel is a vein or an artery is as described above, so a detailed explanation will be omitted here.

When it is determined that the blood vessel is a vein (when the determination is confirmed), the doctor or other user pulls back (retracts) the exploration needle hub 232, as shown in FIG. 11, and changes the tip from the exploration needle 231 to the puncture needle 21. Then, the puncture needle 21 and the catheter needle 31 are inserted into the vein with the needle overlapping (venipuncture).

Next, as shown in FIG. 12, the doctor or other user retracts the exploration needle 231 and the puncture needle 21 into the catheter hub 32 (cylindrical portion 32b). This inserts the catheter 3 into the vein and establishes an infusion line. The doctor or other user then supplies, for example, a medicinal liquid to the patient's vein through the catheter 3 including the infusion tube 34.

As described above in detail, according to this embodiment, for example, before the puncture needle 21 is inserted into the blood vessel (before puncturing), the detection unit 23 (search needle 231) is protruded forward from the tip of the puncture needle 21, thereby making it possible to detect the pulsation of the blood vessel. Then, based on the detected pulsation of the blood vessel, it is possible to determine whether the blood vessel is a vein or an artery. Therefore, before the puncture needle 21 is inserted into the blood vessel, it is possible to determine whether the blood vessel is a vein or an artery. Here, detecting a pulsation also includes detecting the absence of a pulsation. The absence of a pulsation includes not only the case where there is no pulsation at all, but also the case where the peak of the detected signal is below a predetermined threshold.

As a result, it is possible to determine whether a blood vessel is a vein or an artery before puncturing the blood vessel (i.e., without puncturing the blood vessel), and it is possible to prevent accidentally puncturing a vein and an artery (mispuncture). In addition, because it is automatically determined whether a blood vessel is a vein or an artery, the workload on the user can be reduced. Furthermore, even users with low levels of skill can perform accurate punctures.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and various modifications are possible. For example, in the above embodiment, a piezoelectric body is used as the sensor 233, but instead of the piezoelectric body, for example, a diaphragm type pressure sensor may be used.

In place of the piezoelectric body, for example, an optical fiber sensor may be used that detects pulsation from the optical path difference that changes according to the pulsation (vibration). In place of the piezoelectric body, for example, a Doppler sensor may be used that detects pulsation based on the difference in the time it takes for waves such as ultrasound, millimeter waves, infrared rays, and light to travel and return (see Figure 3). Furthermore, in place of the piezoelectric body, an acceleration sensor such as a capacitance type, a piezoresistance type, or a heat detection type may be used.

In the above embodiment, the notification unit 25 uses a red LED 25R indicating that the blood vessel is an artery and a green LED 25G indicating that the blood vessel is a vein. However, instead of the red LED 25R and the green LED 25G, the determination result may be transmitted to the outside for notification (display) using wireless communication such as BLE (Bluetooth (registered trademark) Low Energy).

The materials and manufacturing methods of the above-mentioned components can be the same as those of known medical catheters of the same type, such as synthetic resin molded products made by injection molding and metal products made by various manufacturing methods.

1 Catheter assembly
2 Puncture tool 21 Puncture needle (inner needle)
22 Puncture needle hub (inner needle hub)
23 Detector 231 Probe 232 Probe hub 233 Sensor (piezoelectric body)
24 Determination unit 25 Notification unit 3 Catheter 31 Catheter needle (outer needle)
32 Catheter hub (outer needle hub)
32a: Tapered portion 32b: Cylindrical portion 34: Infusion tube

Claims (11)

A hollow puncture needle capable of puncturing a blood vessel;
a detection unit that can protrude forward from the tip of the puncture needle and detects pulsation of the blood vessel by directly contacting the blood vessel ;
a determination unit that determines whether the blood vessel is a vein or an artery based on the pulsation of the blood vessel detected by the detection unit. The puncture device according to claim 1, characterized in that the detection unit is movably provided inside the hollow puncture needle. The detection unit is
a probe provided movably inside the hollow puncture needle;
a sensor disposed on the rear end side of the probe and detecting the pulsation of a blood vessel transmitted through the probe;
The puncture device according to claim 1 or 2, further comprising: The puncture tool according to claim 3, characterized in that the determination unit determines whether the blood vessel is a vein or an artery based on the amplitude of the blood vessel's pulsation. The puncture device according to claim 4, characterized in that the determination unit confirms the determination result when the same determination result is obtained a predetermined number of times or more. The puncture tool according to any one of claims 3 to 5, characterized in that the sensor detects pressure caused by pulsation of the blood vessel. The puncture tool according to claim 6, characterized in that the sensor is made of a piezoelectric material that outputs an electrical signal corresponding to the pressure caused by the pulsation of the blood vessel. The puncture device according to any one of claims 1 to 7, further comprising a notification unit that notifies the result of the determination as to whether the blood vessel is a vein or an artery. A notification unit is further provided,
The notification unit is capable of notifying a first notification,
The puncture tool according to any one of claims 1 to 7, wherein the notification section issues the first notification when the determination section determines that the target is an artery. The puncture device according to any one of claims 1 to 9,
a catheter that is inscribed on an outer circumferential surface of the puncture tool and slidably houses the puncture tool. The catheter assembly according to claim 10, characterized in that it comprises at least a retraction section that retracts and stores the probe needle constituting the detection section, which is movably provided inside the hollow puncture needle, from the puncture needle.

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