Sensor and catheter

Abstract

To provide a sensor which can be disposed at a proper position and a catheter using the sensor.SOLUTION: A sensor 30 to be used within a lumen 15 of a catheter 100 comprises: a transmission cable 32; a sensor body 31 provided at the tip of the transmission cable 32; a fitting part 34 fitted to the transmission cable 32 or the sensor body 31; and a sensor holder 33 comprising legs 35 extending from the fitting part 34.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a sensor for use within the lumen of a catheter and a catheter using the same.

Background Art

[0002] Acute kidney injury (AKI), which occurs in 30 - 50% of inpatients in intensive care units, has an adverse effect on the prognosis of patients even when it is mild, and the mortality rate when blood purification becomes necessary reaches 60%. In addition, progression to chronic renal failure is also a problem. AKI is caused in part by hypoxia in the renal medulla, and it is thought that the renal medullary oxygen partial pressure can be estimated by measuring the urinary oxygen partial pressure in the bladder. In order to measure the urinary oxygen partial pressure in the bladder, a urethral catheter has been proposed that is provided with an oxygen partial pressure measurement sensor protruding from the urethral catheter to measure the oxygen partial pressure in the bladder or the bladder wall (see, for example, Patent Document 1). In addition, a urethral catheter has been proposed that measures the oxygen partial pressure in the bladder or the bladder wall by providing an oxygen partial pressure measurement sensor within the lumen of the urethral catheter without protruding the oxygen partial pressure measurement sensor.

[0003] In the sensor body of an oxygen partial pressure measurement sensor used in this type of urethral catheter, for example, a phosphor is fixed in a floating state surrounded by a transparent resin within a metal tubular body such as stainless steel having holes for emitting or taking in light for measurement at the tip or around it, and the light supplied from a light source is irradiated through the holes, and the oxygen concentration is measured with an optical fiber formed integrally with the sensor body.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the conventional urethral catheter with an oxygen partial pressure measurement sensor provided in the lumen, the oxygen partial pressure measurement sensor was attached so as to contact the inner peripheral surface of the lumen of the urethral catheter. Generally, the more the surface of the oxygen partial pressure measurement sensor that contacts urine, the higher the measurement accuracy of the oxygen partial pressure in urine. However, when the oxygen partial pressure measurement sensor is stuck to the inner peripheral surface of the lumen of the urethral catheter, a part of the phosphor cannot contact urine and the light absorption situation changes, so there is a risk that the measurement cannot be performed accurately.

[0006] An object of the present invention is to solve the problems of the above-described conventional technology and provide a sensor that can be disposed at an appropriate position and a catheter using the same.

Means for Solving the Problems

[0007] The present invention is a sensor for use in the lumen of a catheter, comprising a transmission cable, a sensor body provided at the tip of the transmission cable, a mounting portion attached to the transmission cable or the sensor body, and a sensor holder having legs extending from the mounting portion.

[0008] In this case, the mounting portion may be formed in an annular shape. The legs may extend radially from the mounting portion. The sensor holder may have three legs provided on the mounting portion at intervals of 120 degrees. The sensor holder may have a frame portion that at least partially surrounds the legs provided at the tips of the legs. The frame portion may surround the legs and the mounting portion.

[0009] Further, the present invention is a catheter, comprising a tube having an opening formed at the tip, and the above-described sensor disposed in the lumen of the tube.

[0010] In this case, it may further include a balloon provided on the outer periphery of the tube, and the sensor body may be located inside the balloon. It may further include a balloon provided on the outer periphery of the tube, and the sensor holder may be located inside the balloon.

Advantages of the Invention

[0011] In the present invention, it is possible to provide a sensor that can be disposed at an appropriate position and a catheter using the same.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0013] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. (First Embodiment) FIG. 1 shows a side view of the balloon catheter, FIG. 2(a) shows a cross-sectional view of the tip of the balloon catheter with the balloon contracted, FIG. 2(b) shows a longitudinal sectional view of the tube, FIG. 3 shows a cross-sectional view of the proximal end of the balloon catheter, FIG. 4(a) shows a perspective view of the sensor with the sensor holder removed, and FIG. 4(b) shows a perspective view of the sensor with the sensor holder attached.

[0014] As shown in FIG. 1, the balloon catheter 100 includes a catheter body 10, a sensor 30, and a fixing portion 40. This balloon catheter 100 is a product in which the fixing portion 40 is attached to the catheter body 10, and the sensor 30 is fixed to the catheter body 10 via the fixing portion 40 and integrated.

[0015] The catheter body 10 is composed of a tip portion 11, a tube 12, a balloon 13, and a branch portion 14. On the tip side of the catheter body 10, the tip portion 11 and the balloon 13 are connected to the tube 12, while on the proximal end side of the catheter body 10, the branch portion 14 is connected to the tube 12 and integrally formed.

[0016] The tip portion 11, the tube 12, the balloon 13, and the branch portion 14 are formed of silicone rubber, but may be formed of latex, natural rubber, isoprene rubber, thermoplastic resin, for example, PVC and urethane rubber, fluororubber, and fluororesin.

[0017] As shown in FIG. 2(a), the tube 12 passes through the balloon 13, and the balloon 13 is provided on the outer periphery near the tip by adhesion. Further, the tube 12 has a tip portion 11 formed in a cylindrical shape attached to the end face of the tip by adhesion. The tube 12 has a urine drainage lumen (inner cavity) 15 formed along the extending direction of the tube 12 for flowing urine. The urine drainage lumen 15 communicates with the outside through a tip hole (opening) 16 and a side hole (opening) 17 formed in the tip portion 11, and the urine flowing in from the tip hole 16 and the side hole 17 flows through the urine drainage lumen 15 to the branch portion 14 on the proximal end side.

[0018] Part of the tube 12 is formed with a thick wall, and a balloon lumen 18 for inflating the balloon 13 is formed along the extending direction of the tube 12 in the thick-walled portion. The balloon lumen 18 is fluidly connected to the inside of the balloon 13 near the tip, and the balloon 13 is inflated by filling the inside of the balloon 13 with the sterilized water supplied from the branch portion 14 on the proximal end side.

[0019] As shown in FIG. 2(b), the urine drainage lumen 15 is formed to have a substantially circular cross-sectional flow path, and the balloon lumen 18 is formed to have a circular cross-sectional flow path smaller than that of the urine drainage lumen 15.

[0020] As shown in FIG. 2(a), the balloon 13 is formed to have a cylindrical shape when not inflated. The non-inflated portions on the tip side and the proximal end side of the balloon 13 are formed in a tapered shape, and the outer diameter smoothly decreases toward the tip and the proximal end. When sterilized water is supplied from the branch portion 14 through the balloon lumen 18, the balloon 13 expands into a spherical shape centered on the tube 12 between the tip-side expansion end 13A and the proximal-end side expansion end 13B. Thereby, the balloon catheter 100 is fixed so that the balloon 13 is caught in the patient's bladder and does not come out.

[0021] As shown in FIG. 3, one end of the branch portion 14 is connected to the tube 12 on the tip side, while the other end on the proximal end side is divided into three: a balloon injection port 19, a transmission cable insertion port 20, and a urine outlet 21.

[0022] The balloon injection port 19 is fluidly connected to the balloon lumen 18 and can be connected to a reservoir (not shown) for injecting sterilized water into the balloon lumen 18.

[0023] The transmission cable insertion port 20 extends linearly with respect to the urine discharge lumen 15, and the sensor 30 inserted straight into the transmission cable insertion port 20 is directly inserted into the urine discharge lumen as it is.

[0024] The urine discharge port 21 extends obliquely with respect to the urine discharge lumen 15, and can be connected to a urine discharge tube (not shown) or the like, and is adapted to be connected to a urine bag or the like via the urine discharge tube.

[0025] The sensor 30 inserted into the transmission cable insertion port 20 includes a sensor body 31, a transmission cable 32, and a sensor holder 33 as shown in Fig. 4(a). The sensor body 31, the transmission cable 32, and the sensor holder 33 are formed separately. The sensor 30 according to the present embodiment is an oxygen partial pressure measurement sensor, the sensor body 31 is an excitation light irradiation unit, the transmission cable 32 is an optical fiber, and the transmission cable 32 is formed of a material harder and having a stronger elastic force than the tube 12. A phosphor is applied in the urine discharge lumen 15 of the tube 12, and the light sent from the transmission cable 32 is irradiated from the sensor body 31 to the phosphor.

[0026] The sensor body 31 is provided at the tip of the transmission cable 32 and is movable together with the transmission cable 32 in the urine discharge lumen 15 in a state where the sensor holder 33 is not attached. That is, the sensor body 31 can be curved independently of the curvature of the tube 12 in the urine discharge lumen 15.

[0027] The sensor holder 33 has a mounting portion 34 attached to the transmission cable 32 or the sensor body 31, and leg portions 35 extending from the mounting portion 34.

[0028] The mounting portion 34 is formed in an annular shape and is formed such that the outer peripheral surfaces of the sensor body 31 and the transmission cable 32 fit within the inner peripheral surface. Thereby, as shown in Fig. 4(b), it is attached to the transmission cable 32 through the sensor body 31.

[0029] The leg portion 35 is provided on the mounting portion 34 and is formed of a thin and elastic material such as hair or a brush. In the sensor holder 33 according to the present embodiment, three leg portions 35, 35, 35 are provided on the mounting portion 34 at intervals of 120 degrees, and each leg portion 35 extends radially from the center of the annular shape portion of the mounting portion 34. Thereby, when the sensor 30 is inserted into the urinary lumen 15, the leg portion 35 of the sensor holder 33 contacts the inner peripheral surface of the urinary lumen 15, so that the sensor main body 31 is held at the center of the urinary lumen 15.

[0030] When attaching the sensor holder 33 to the transmission cable 32, first, the operator causes the sensor main body 31 and the transmission cable 32 inserted from the proximal end side of the catheter main body 10 to protrude outside from the tip hole 16 of the catheter main body 10.

[0031] Next, after the operator attaches the sensor holder 33 to the transmission cable 32, the operator pulls back the sensor main body 31 to the inside of the balloon 13, and fixes the transmission cable 32 with the fixing portion 40 of the catheter main body 10 in this state.

[0032] As shown in FIG. 3, the fixing portion 40 is attached to the transmission cable insertion port 20, and the sensor 30 is fixed to the tube 12 via the fixing portion 40 that fixes the transmission cable 32.

[0033] The fixing portion 40 includes a fixing portion main body 41, a fixing portion cap 42, and a tightening portion 43. This tightening portion 43 has an annular shape in which a through hole 43A through which the transmission cable 32 can penetrate is formed at the center. The tightening portion 43 is sandwiched between the fixing portion main body 41 and a fixing portion cap 42 screwed into the fixing portion main body 41. When the fixing portion cap 42 is screwed into the fixing portion main body 41, the tightening portion 43 is crushed and the diameter of the through hole 43A becomes smaller. Thereby, the tightening portion 43 tightens the transmission cable 32 to fix the transmission cable 32.

[0034] As shown in Fig. 2(a), the length from the end face on the proximal end side of the fixing portion 40 to the tip of the sensor body 31 is shorter than the length from the end face on the proximal end side of the fixing portion 40 to the tip-side expansion end 13A of the balloon 13, and is longer than the length from the end face on the proximal end side of the fixing portion 40 to the proximal-end expansion end 13B of the balloon 13.

[0035] The sensor body 31 is fixed by the transmission cable 32 being fixed to an appropriate length at the fixing portion 40, so that it is held inside the balloon 13 without being fixed by adhesion or the like within the urine drainage lumen 15 of the tube 12. At this time, the sensor holder 33 attached to the transmission cable 32 in the vicinity of the sensor body 31 is slidably positioned inside the balloon 13 within the tube 12. Thereby, since the sensor 30 is held at a position that is harder and less bendable than other parts due to the balloon 13 being provided in the catheter body 10, it is difficult for the force due to the bending of the catheter body 10 to be applied, and it can slide smoothly within the urine drainage lumen 15.

[0036] The balloon catheter 100 according to the present embodiment includes a tube 12 having a tip hole 16 and side holes 17 formed at the tip, a balloon 13 provided on the outer periphery of the tube 12, and a sensor 30 disposed within the urine drainage lumen 15 of the tube 12. Further, this sensor 30 includes a transmission cable 32, a sensor body 31 provided at the tip of the transmission cable 32, an attachment portion 34 attached to the transmission cable 32, and a sensor holder 33 having legs 35 extending from the attachment portion 34. Thereby, the sensor body 31 is held at the center of the urine drainage lumen 15 with a gap from the inner peripheral surface of the urine drainage lumen 15, and can contact the urine flowing within the urine drainage lumen 15 on all surfaces other than the surface in contact with the transmission cable 32. For this reason, the sensor body 31 can be disposed at an appropriate position.

[0037] (Second Embodiment) Fig. 5(a) shows a perspective view of the sensor with the sensor holder according to the second embodiment attached, and Fig. 5(b) shows a longitudinal sectional view of the tube according to the second embodiment.

[0038] Hereinafter, members that are substantially the same as those in the first embodiment will be described using the same reference numerals. As shown in Fig. 5(a), the sensor 130 according to the second embodiment differs from the sensor 30 according to the first embodiment in the configuration of the sensor holder 133.

[0039] In the sensor holder 133 according to this embodiment, two legs 35, 35 are provided on the mounting portion 34 at an interval of 180 degrees, and each leg 35 extends radially from the center of the annular shape portion of the mounting portion 34.

[0040] The sensor holder 133 is provided with a frame portion 136 formed so as to surround the mounting portion 34 and the two legs 35, 35 at the tip of the leg 35, and the two legs 35, 35 support the frame portion 136. As shown in Fig. 5(b), this frame portion 136 is formed in a shape that slidably fits on the inner peripheral surface of the urine drainage lumen 15. Thereby, the sensor 130 is accurately positioned on the inner peripheral surface of the urine drainage lumen 15 and can slide smoothly within the urine drainage lumen 15.

[0041] Although the present invention has been described based on the embodiments above, the present invention is not limited thereto. For example, in the above embodiment, the sensor holder 33 is attached to the transmission cable 32, but it is not limited to this. As long as the sensor main body 31 is held at the center of the urine drainage lumen 15, the sensor holder 33 may be attached to the sensor main body 31.

[0042] Also, in the above embodiment, the sensor holder 33 having three legs 35 or the sensor holder 133 having two legs 35 is used, but it is not limited to this. As long as the sensor main body 31 is held at the center of the urine drainage lumen 15, the number of legs 35 is not limited.

[0043] Furthermore, in the second embodiment, the frame portion 136 is formed over the entire circumference so as to surround all of the attachment portion 34 and the two leg portions 35, 35, but it is not limited thereto. The frame portion may be formed so as to surround at least a part of the leg portion 35 as long as it is provided at the tip of the leg portion 35.

[0044] Furthermore, in the above embodiment, the sensor holder 33 is attached with the sensor body 31 and the transmission cable 32 protruding outside from the tip hole 16 of the catheter body 10, but it is not limited thereto. The sensor holder 33 may be attached to the transmission cable 32 or the sensor body 31 in advance.

[0045] Also, in the above embodiment, the sensor holder 33 is fitted inside the tube 12, but it is not limited thereto. As long as the sensor body 31 is held at the center of the urine drainage lumen 15, the sensor holder 33 may be fitted inside the tip portion 11 of the catheter body 10.

[0046] Furthermore, in the above embodiment, the sensors 30, 130 including the irradiation unit and the optical fiber are used, but it is not limited thereto. As long as it is a sensor capable of measuring the oxygen partial pressure, a sensor based on other methods may be used.

Explanation of Reference Numerals

[0047] 10…Catheter body 11…Tip portion 12…Tube 13…Balloon 14…Branching portion 15…Urine drainage lumen (inner cavity) 16…Tip hole 17…Side hole 18…Balloon lumen 19…Balloon injection port 20…Transmission cable insertion port 21…Urine outlet 30…Sensor 31…Sensor body 32…Transmission cable 33…Sensor holder 34…Attachment portion 35…Foot part 40…Fixing part 41…Fixing part body 42…Fixing part cap 43…Tightening part 43A…Through hole 100…Balloon catheter 130…Sensor 133…Sensor holder 136…Frame part 13A…Tip-side expansion end 13B…Base-side expansion end

Claims

1. A sensor for use within the lumen of a catheter, comprising a transmission cable, a sensor body provided at the tip of the transmission cable, and a sensor holder having a mounting portion attached to the transmission cable or the sensor body, and legs extending from the mounting portion.

2. The sensor according to claim 1, wherein the mounting portion is formed in an annular shape.

3. The sensor according to claim 1, wherein the legs extend radially from the mounting portion.

4. The sensor according to claim 1, wherein the sensor holder has three legs provided on the mounting portion at 120-degree intervals.

5. The sensor according to claim 1, wherein the sensor holder has a frame portion at least partially surrounding the legs provided at the tips of the legs.

6. The sensor according to claim 5, wherein the frame portion surrounds the legs and the mounting portion.

7. In a catheter, a tube having an opening formed at the tip, and a sensor according to any one of claims 1 to 6 disposed within the lumen of the tube.

8. The catheter according to claim 7, further comprising a balloon provided on the outer periphery of the tube. The catheter, wherein the sensor body is positioned inside the balloon.

9. In the catheter according to claim 7, further comprising a balloon provided on the outer periphery of the tube, The catheter, wherein the sensor holder is positioned inside the balloon.

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