Puncture tool and catheter assembly

Abstract

To provide a puncture tool capable of discriminating whether a blood vessel is a vein or an artery before puncturing the blood vessel (namely, without puncturing the blood vessel), and preventing a vein and an artery from being punctured erroneously, mistaking a vein for an artery and vice versa (erroneous puncturing), and to provide a catheter assembly equipped with the puncture tool.SOLUTION: A catheter assembly 1 includes a puncture tool 2 and a catheter 3. The puncture tool 2 includes a hollow puncture needle 21 for puncturing a blood vessel, a detection part 23 that can protrude before the tip of the puncture needle 21 for detecting pulsation of a blood vessel, and a determination part 24 for determining whether the blood vessel is a vein or an artery on the basis of the pulsation of the blood vessel detected by the detection part 23. The detection part 23 includes a probing needle 231 provided inside the hollow puncture needle 21 so as to advance and retract in the axial direction, and a sensor 233 for detecting the pulsation of the blood vessel transmitted through the probing needle 231.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a puncture device and a catheter assembly including the puncture device. [Background technology]

[0002] Conventionally, in medical situations, such as in central venous puncture for inserting a catheter into a vein to perform infusion, puncture of a patient's internal tissue has been performed. 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 ultrasonic diagnostic device.

[0003] Here, 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 operator 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. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-175191 A Summary of the Invention [Problem to be solved by the invention]

[0005] According to the technology of the above-mentioned Patent Document 1, it is possible to recognize that a blood vessel has been punctured without visually checking the backflow of blood (flashback) caused by the puncture. However, it is not possible to know whether the blood vessel into which the needle has been punctured is a vein or an artery until the needle is inserted into the blood vessel (i.e., until after the needle has been inserted). Therefore, it is difficult to prevent the puncture of a vein and an artery by mistake (mispuncture).

[0006] The present invention has been made to solve the above-mentioned problems, and has an object 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 accidentally puncturing a vein and an artery (mispuncture), and a catheter assembly equipped with the puncture device. [Means for solving the problem]

[0007] The puncture device of the present invention is characterized in that it comprises a hollow puncture needle to be 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.

[0008] A 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 houses the puncture tool so as to be slidable in the axial direction.

[0009] 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 erroneous puncturing of a vein and an artery (mispuncture). Effect of the Invention

[0010] 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). [Brief description of the drawings]

[0011] [Figure 1]1 is a perspective view showing a puncture device according to an embodiment, and a catheter assembly including the puncture device. [Diagram 2] 5A and 5B are schematic diagrams showing the configuration of a detection section constituting the puncture tool according to the embodiment. [Diagram 3] 13 is a schematic diagram showing another example of a detection section constituting the puncture tool according to the embodiment. FIG. [Figure 4] 1A and 1B are diagrams showing a state of a puncture tool according to an embodiment before and after retraction, respectively. [Diagram 5] 6A and 6B are diagrams showing an example of a notification section constituting the puncture tool according to the embodiment; [Figure 6] FIG. 13 is a diagram showing the impedance characteristics (peak shift) of the sensor before and after contact with the blood vessel. [Figure 7] FIG. 1 is a diagram showing the amplitude of pulsation (pressure) of a vein and an artery. [Figure 8] 1A to 1C are diagrams (part 1) illustrating a puncture method (puncture procedure) using a catheter assembly according to an embodiment. [Figure 9] FIG. 2 is a diagram (part 2) showing a puncture method (puncture procedure) using the catheter assembly according to the embodiment. [Figure 10] FIG. 3 is a view (part 3) showing a puncture method (puncture procedure) using the catheter assembly according to the embodiment. [Figure 11] FIG. 4 is a diagram (part 4) showing a puncture method (puncture procedure) using the catheter assembly according to the embodiment. [Figure 12] FIG. 5 is a diagram (part 5) showing a puncture method (puncture procedure) using the catheter assembly according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals will be used for the same or corresponding parts. In each drawing, the same reference numerals will be used for the same elements, and duplicated explanations will be omitted.

[0013] First, the configuration of a puncture tool 2 according to an embodiment and a catheter assembly 1 including the puncture tool 2 will be described with reference to Figures 1-2, 4-5. Figure 1 is a perspective view showing a puncture tool 2 and a catheter assembly 1 including the puncture tool 2. Note that Figure 1 shows a state in which a puncture needle 21 and a puncture needle hub 22 are pulled backward. Figure 2 is a schematic diagram showing a configuration of a 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.

[0014] A catheter assembly 1 equipped with a puncture tool 2 punctures body tissue (skin, blood vessels, etc.) and inserts a catheter 3 into a vein, for example, to perform infusion or the like.

[0015] In particular, the catheter assembly 1 equipped with the puncture device 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 accidental puncture of a vein and an artery (mispuncture).

[0016] Therefore, the catheter assembly 1 is configured to include a puncture tool 2, and a catheter 3 that is inscribed on the outer circumferential surface of the puncture tool 2 and houses the puncture tool 2 so as to be slidable (relatively movable) in the axial direction. Each component will be described in detail below.

[0017] 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 is capable of protruding 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.

[0018] 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 or the like to guide the catheter needle 31. The base end of the puncture needle 21 is held by a 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 relatively movable in the axial direction.

[0019] Detection unit 23 is provided inside (inner side) hollow puncture needle 21 so as to be freely movable forward and backward in the axial direction (i.e., movable relative to puncture needle 21). This suppresses the effect of pressure from body tissues when puncturing, and allows for more accurate detection of blood vessel pulsation. In addition, sensing can be performed at the needle tip closer to the blood vessel, allowing for highly sensitive detection of pulsation. If detection unit 23 can protrude even slightly forward from puncture needle 21, it is possible to prevent puncturing a vein instead of an artery by mistake.

[0020] More specifically, the detection unit 23 is configured to include an exploration needle 231 that is arranged inside the hollow puncture needle 21 so as to be able to move back and forth in the axial direction (relatively movable), an exploration needle hub 232 that holds the exploration needle 231, and a sensor 233 that is arranged on the rear end side of the exploration needle 231 and detects the pulsation of the blood vessel transmitted via the exploration needle 231.

[0021] The probe 231 is formed in a long and thin rod shape with a substantially 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, so that the pulsation of the blood vessel can be detected with higher sensitivity.

[0022] The search needle hub 232 holds the search needle 231 at its base end. The search needle hub 232 is formed in a stepped cylindrical shape that includes a reduced diameter portion at the tip side and an expanded diameter portion connected to the reduced diameter portion. By rotating the search needle hub 232 in the circumferential direction, the search needle 231 can be advanced or retracted in the axial direction.

[0023] 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, a voltage) according 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 accommodated in the thin probe hub 232. Furthermore, in the method of detecting pressure, it is sufficient to touch the blood vessel and it does not depend on the way of application, so there is little measurement error due to individual differences, and even a user with a relatively low level of technical proficiency can accurately detect. On the other hand, in the method of detecting pressure, pressure cannot be detected when it is separated from the blood vessel wall, so the possibility of misidentifying it as a vein can be reduced.

[0024] FIG. 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 FIG. 6 is frequency (Hz), and the vertical axis is impedance (Ω) of the sensor (piezoelectric body) 233. As shown in FIG. 6, the peak value of the impedance decreases and the peak frequency of the impedance shifts to a higher frequency side (peak shift) after contact with the blood vessel, compared to before contact with the blood vessel. Therefore, by detecting the peak shift or impedance difference of the impedance of the sensor (piezoelectric body) 233, it can be determined whether or not the probe 231 has contacted the blood vessel. The electric signal detected by the sensor 233 is output to the determination unit 24.

[0025] The determination unit 24 determines whether the blood vessel is a vein or an artery based on the magnitude of the amplitude (= pressure) of the blood vessel pulsation detected by the sensor 233, for example. Here, the amplitude of the pulsation of each 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, when the detection value of the sensor 233 is less than a predetermined threshold value set between the minimum value of the amplitude of the artery and the maximum value of the amplitude of the vein, the determination unit 24 determines that the blood vessel in contact is a vein. On the other hand, when the detection value of the sensor 233 is equal to or greater than the predetermined threshold value, the determination unit 24 determines that the blood vessel in contact is an artery. Note that the greater the pulsation, the greater the amount of peak shift in the impedance of the sensor (piezoelectric body) 233 described above. Therefore, the amount of peak shift in the artery is greater than that in the vein. Therefore, whether the blood vessel is an artery or a vein may be determined based on the amount of peak shift in the impedance. In addition, the determination of whether it is an artery or a vein includes not only a direct determination, but also an 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.

[0026] Furthermore, when the same determination result (determination result of whether it is a vein or an artery) is obtained a predetermined number of times or more (for example, two or more consecutive times), the determination unit 24 confirms the determination result. In this way, the influence of pulse-like noise and the like can be eliminated, and a more accurate determination can be achieved (erroneous determination can be prevented). The determination unit 24 may be configured (software) with a CPU that executes calculations and a memory that stores programs and data, or may be configured (hardware) with a comparator consisting of an operational amplifier or the like. The determination result by the determination unit 24 is output to the notification unit 25.

[0027] 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.

[0028] 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 as to be slidable (relatively movable) in the axial direction.

[0029] The catheter needle 31 is a flexible, thin-diameter tubular member, and 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. The catheter needle 31 is preferably made of a resin material, particularly a soft resin material.

[0030] In the initial state (state before retraction), the puncture needle (inner needle) 21 is disposed with its tip protruding inside the catheter needle (outer needle) 31. In addition, as described above, the exploration needle 231 is disposed inside the puncture needle 21.

[0031] The catheter hub 32 is a stepped hollow cylindrical member that holds the base end of the catheter needle 31, and is configured to include 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 configured from a transparent resin so that all or part of the inside can be visually observed.

[0032] As shown in FIG. 4(b), the catheter hub 32 is configured so that the lookup 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 a retraction section as described in the claims. FIG. 4(b) is a diagram showing a state in which the puncture needle 21 and the lookup needle 231 have been retracted into the catheter hub 32. By retracting the puncture needle 21 and the lookup needle 231 into the catheter hub 32 in this way, it is possible to prevent the flow of medicinal liquid or blood from being obstructed by the lookup needle 231, etc., when injecting medicinal liquid, collecting blood, etc.

[0033] 12, the infusion tube 34 passes through the inside (hollow portion) of the stylet hub 232 and is liquid-tightly connected to the catheter hub 32 (cylindrical portion 32b). Thus, for example, a medicinal liquid or the like can be supplied to the patient's vein through the catheter 3 including the infusion tube 34.

[0034] Next, a method of using the catheter assembly 1 (a 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.

[0035] 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 with the tip protruding. Also, the exploration needle 231 is placed inside the puncture needle 21 (with the tip not protruding).

[0036] Next, as shown in FIG. 9, a user such as a doctor rotates (rotates) the exploration needle hub 232 around the axis, thereby releasing the engagement between the exploration needle 231 and the exploration needle hub 232 that holds the exploration needle 231 and the puncture needle hub 22 that holds the puncture needle 21, and causing the exploration needle 231 to protrude forward beyond the tip of the puncture needle 21.

[0037] Next, a user such as a doctor protrudes the probe 231 and places it against the blood vessel wall as shown in Fig. 10 to determine whether the blood vessel is a vein or an artery. Note that the method of determining whether the blood vessel is a vein or an artery is as described above, and therefore a detailed description thereof will be omitted here.

[0038] When the blood vessel is determined to be a vein (when the determination is confirmed), a user such as a doctor 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 (venipuncture) with the needle overlapping each other.

[0039] Next, as shown in Fig. 12, the user such as a doctor retracts the exploration needle 231 and the puncture needle 21 and retracts them into the catheter hub 32 (cylindrical portion 32b). This causes the catheter 3 to be inserted into the vein and an infusion line is established. Thereafter, the user such as a doctor supplies, for example, a medicinal liquid to the patient's vein through the catheter 3 including the infusion tube 34.

[0040] As described above in detail, according to this embodiment, for example, before the puncture needle 21 is inserted into (punctures) a blood vessel, the pulsation of the blood vessel can be detected by projecting the detection unit 23 (search needle 231) forward of the tip of the puncture needle 21. 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 21 is inserted into the blood vessel, it can be determined 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 less than a predetermined threshold value.

[0041] 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 puncturing a vein and an artery by mistake (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 skill levels can perform accurate puncture.

[0042] 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.

[0043] Also, instead of the piezoelectric body, for example, an optical fiber sensor that detects pulsation from an optical path difference that changes according to pulsation (vibration) may be used. Also, instead of the piezoelectric body, for example, a Doppler sensor that detects pulsation based on the difference in the time it takes for waves such as ultrasonic waves, millimeter waves, infrared rays, and light to travel and return may be used (see FIG. 3). Furthermore, instead of the piezoelectric body, an acceleration sensor such as a capacitance type, a piezoresistance type, or a heat detection type may be used.

[0044] In the above embodiment, 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 are used as the notification unit 25. However, instead of the red LED 25R and the green LED 25G, the determination result may be transmitted to the outside using wireless communication such as BLE (Bluetooth (registered trademark) Low Energy) to notify (display).

[0045] The materials and manufacturing methods of the above-mentioned components may be the same as those of known medical catheters of the same type, such as synthetic resin molded products manufactured by injection molding or metal products manufactured by various methods. [Explanation of symbols]

[0046] 1 Catheter assembly 2 Puncture device 21 Puncture needle (inner needle) 22 Puncture needle hub (inner needle hub) 23 Detection unit 231 Probe 232 Probe Hub 233 Sensor (Piezoelectric) 24 Judgment section 25 Notification Department 3 Catheter 31 Catheter needle (outer needle) 32 Catheter hub (outer needle hub) 32a Tapered section 32b Cylindrical part 34 Infusion tube

Claims

1. 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.

2. The puncture device according to claim 1 , wherein the detection unit is movably provided inside the hollow puncture needle.

3. 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:

4. The puncture tool according to claim 3 , wherein the determination section determines whether the blood vessel is a vein or an artery based on the amplitude of the pulsation of the blood vessel.

5. The puncture device according to claim 4, wherein the determination section confirms a determination result when the same determination result is obtained a predetermined number of times or more.

6. 6. The puncture tool according to claim 3, wherein the sensor detects pressure caused by pulsation of the blood vessel.

7. 7. The puncture tool according to claim 6, wherein the sensor is made of a piezoelectric material that outputs an electric signal corresponding to pressure caused by pulsation of the blood vessel.

8. The puncture tool according to any one of claims 1 to 7, further comprising a notification unit that notifies a result of a determination as to whether the blood vessel is a vein or an artery.

9. A notification unit is further provided, The notification unit is capable of notifying a first notification, The notification unit issues the first notification when the determination unit determines that the tissue is an artery. The puncture device according to any one of claims 1 to 7.

10. 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.

11. 11. The catheter assembly according to claim 10, further comprising a retraction section for retracting and storing at least a probe needle constituting the detection section, the probe needle being movably provided inside the hollow puncture needle, from the puncture needle.

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