JP5425151B2 - Pressure detector - Google Patents

Description

  The present invention is connected to an extracorporeal circuit for circulating a patient's blood extracorporeally, and can circulate blood circulating extracorporeally in the extracorporeal circuit and is displaced in the radial direction according to the pressure in the extracorporeal circuit. The present invention relates to a possible pressure detector.

  The extracorporeal circuit used for blood purification treatment such as hemodialysis treatment is usually an arterial blood circuit to which an arterial puncture needle can be attached at the tip, and a venous blood circuit to which a venous puncture needle can be attached to the tip. A blood purifier such as a dialyzer is connected between the proximal end of the arterial blood circuit and the proximal end of the venous blood circuit. In the middle of the arterial blood circuit, a squeezing part made of a soft and large-diameter flexible tube is connected, and when the squeezing part is squeezed by a roller of a blood pump, the patient's blood enters the extracorporeal circuit. Therefore, extracorporeal circulation is possible.

  However, in the process of circulating blood extracorporeally, negative pressure may occur in the upstream side of the blood pump, particularly in the arterial blood circuit. Therefore, in the middle of the extracorporeal circuit (specifically, the arterial blood circuit). An extracorporeal circuit in which a negative pressure detection unit (pressure detection unit) for detecting the negative pressure is connected to the upstream side of the blood pump in the blood pump has been proposed. As shown in FIGS. 9 and 10, the conventional negative pressure detection unit includes a flexible hollow member 100 having an internal space 100 a having a predetermined capacity, and blood flowing in the artery-side blood circuit L has negative pressure. If it becomes, it was comprised so that a surface part and a back surface part might bend in the direction which adjoins.

JP 2006-340845 A

  However, in the conventional pressure detection unit, since the entire shape is formed into a flat shape, there is a problem that a portion where blood stagnates in the internal space 100a (that is, a portion where a blood retention portion easily occurs) occurs. was there. That is, if blood stagnates in the staying part in the pressure detection part, the stagnation blood may easily become a thrombus and cause a problem.

  The present invention has been made in view of such circumstances, and a pressure detection unit capable of suppressing the formation of a thrombus in blood in an extracorporeal circulation process by making the shape of a blood retention portion as small as possible. Is to provide.

The invention according to claim 1 is arranged between two connection parts connected to an extracorporeal circuit for circulating the patient's blood extracorporeally, and arranged in a radial direction according to the pressure of the extracorporeal circuit. In the pressure detection section provided with a response section that is displaceable, the radial section of the response section and the connection section is circular or elliptical, and the inner diameter of the response section is larger than the inner diameter of the connection section. The connection portion has a tapered surface inclined so that the inner diameter gradually increases toward the response portion , and the connection portion on the inlet side into which blood is introduced from the extracorporeal circuit However, the gradient angle of the tapered surface is set to be smaller than that of the connecting portion on the outlet side for leading blood to the extracorporeal circuit .

  According to a second aspect of the present invention, in the pressure detecting unit according to the first aspect, the tapered surface is formed so that the inner diameter is expanded substantially uniformly over the entire circumferential direction.

  According to a third aspect of the present invention, in the pressure detection unit according to the first or second aspect, the response unit is set to be more easily bent in the radial direction than the connection unit.

  According to a fourth aspect of the present invention, in the pressure detection unit according to the third aspect, the response unit and the connection unit are integrally formed, and the response unit is set smaller than the thickness of the connection unit. And

  According to a fifth aspect of the present invention, in the pressure detection unit according to the third aspect, the response unit is formed of a softer material than the connection unit.

  A sixth aspect of the invention is characterized in that, in the pressure detector according to any one of the first to fifth aspects, the response portion has a substantially uniform thickness over the entire circumference.

The invention according to claim 7 is the pressure detector according to any one of claims 1 to 6, wherein the inclination angle of the tapered surface of the connecting portion on the inlet side is set to 20 to 60 °, The gradient angle of the tapered surface of the connecting portion on the outlet port side is 20 to 90 ° .

  The invention according to claim 8 is an extracorporeal circuit characterized in that any one of the pressure detectors according to claims 1 to 7 is connected.

According to the invention of claim 1, the cross section in the radial direction of the response portion and the connection portion is circular or elliptical, the inner diameter of the response portion is larger than the inner diameter of the connection portion, and the connection portion is directed toward the response portion. Since it has a tapered surface inclined so that the inner diameter gradually increases, it is possible to suppress the formation of a thrombus in the blood in the extracorporeal circulation process by making the shape of the blood retention portion as small as possible.
Furthermore, since the connecting portion on the inlet side where blood is introduced from the extracorporeal circuit is set to have a smaller inclination angle of the tapered surface than the connecting portion on the outlet side that leads blood to the extracorporeal circuit, In addition, it is possible to make the shape where the blood retention portion is reduced as much as possible, and to reduce the total length of the pressure detection portion.

  According to the invention of claim 2, since the taper surface is formed so that the inner diameter expands substantially uniformly over the entire circumferential direction, it is possible to further reduce the blood retention portion as much as possible. It is possible to more reliably suppress thrombus formation in blood in the extracorporeal circulation process.

  According to the third aspect of the present invention, since the response portion is set to be more easily bent in the radial direction than the connection portion, stable response and shape restoration can be obtained. That is, since the response portion is supported by the connection portion that is difficult to bend in the radial direction, the response portion can be favorably displaced in the radial direction, and the displaced response portion can be smoothly and reliably restored to the original state. It is possible to return.

  According to the invention of claim 4, since the response portion and the connection portion are integrally formed and the response portion is set smaller than the thickness of the connection portion, the response portion is more easily diameter than the connection portion. It can be set to be easily bent in the direction, and stable responsiveness and shape restoration can be obtained.

  According to the invention of claim 5, since the response portion is formed of a softer material than the connection portion, the response portion can be set more easily and more easily in the radial direction than the connection portion. Responsiveness and shape restoration can be obtained.

  According to the sixth aspect of the present invention, since the response portion has a substantially uniform thickness over the entire circumference, the displacement is made more stable when displaced in the radial direction according to the pressure in the extracorporeal circuit. be able to.

  According to invention of Claim 8, the extracorporeal circuit to which any one pressure detection part of Claims 1-7 was connected can be provided.

The schematic diagram which shows the external circulation circuit to which the pressure detection part which concerns on embodiment of this invention was connected. Front view showing the pressure detector Sectional view taken along line III-III in FIG. Sectional view along line IV-IV in FIG. Graph to show the response evaluation of the pressure detector The front view which shows the pressure detection part which concerns on other embodiment of this invention. VII-VII line sectional view in FIG. VIII-VIII sectional view taken on the line in FIG. Front view showing a conventional pressure detector XX sectional view in FIG.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
The pressure detection unit according to the present embodiment is a blood circuit (specifically, upstream of a site where a blood pump is provided) for circulating blood of a patient extracorporeally to perform blood purification treatment (for example, hemodialysis treatment). As shown in FIG. 1, the blood circuit to be applied is an arterial blood circuit 1, a venous blood circuit 2, and a blood purifier. And the dialyzer 3 as a main component. The arterial blood circuit 1 and the venous blood circuit 2 correspond to the “extracorporeal circuit” of the present invention.

  The arterial blood circuit 1 constitutes a liquid flow path composed of a flexible tube through which a predetermined liquid can be circulated, and an arterial puncture needle a can be attached to the tip thereof via a connector c. An arterial air trap chamber 5 for removing bubbles is connected on the way. Further, an ironing tube 1a is connected in the middle of the artery-side blood circuit 1 (between the pressure detection unit 7 and the artery-side air trap chamber 5), and the ironing tube 1a is attached to the blood pump 4. Is possible. The ironing tube 1a can be compressed in the longitudinal direction while being compressed in the radial direction by the roller 4a (ironing part) of the blood pump 4 (ironing type pump) to flow the internal liquid in the rotational direction of the roller 4a. It consists of a flexible tube that is softer and larger in diameter than the other flexible tubes that make up the arterial blood circuit 1.

  The venous blood circuit 2 constitutes a liquid flow path composed of a flexible tube through which a predetermined liquid can be circulated, and a venous puncture needle b can be attached to its tip via a connector d. A vein-side air trap chamber 6 for removing bubbles is connected on the way. However, the flexible tube constituting the venous blood circuit 2 has substantially the same material and dimensions as the flexible tube constituting the arterial blood circuit 1. A dialyzer 3 is connected between the arterial blood circuit 1 and the venous blood circuit 2.

  The dialyzer 3 is formed by housing a plurality of hollow fibers in which micropores (pores) are formed in a casing, and the blood inlet port 3a, blood outlet port 3b, dialysate inlet port are provided in the casing. 3c and dialysate outlet port 3d are formed, and the blood introduction port 3a is connected to the proximal end of the arterial blood circuit 1, and the blood outlet port 3b is connected to the proximal end of the venous blood circuit 2. Yes. The dialysate introduction port 3c and the dialysate lead-out port 3d are respectively connected to a dialysate introduction line L1 and a dialysate discharge line L2 extending from the dialyzer body (not shown).

  The patient's blood introduced into the dialyzer 3 passes through the inside hollow fiber membrane (blood flow path) and is discharged from the blood outlet port 3b, while the dialysate introduced from the dialysate inlet port 3c It passes through the hollow fiber membrane (dialysate flow path) and is discharged from the dialysate discharge port 3d. As a result, wastes or the like in the blood passing through the blood channel can be permeated to the dialysate side to be purified, and the clean blood can be returned to the patient's body via the venous blood circuit 2. it can

  Here, in the middle of the arterial blood circuit 1 (upstream from the site where the blood pump 4 is disposed), blood circulating outside the body in the arterial blood circuit 1 and the venous blood circuit 2 can be circulated, A pressure detector 7 that can be displaced in the radial direction according to the pressure in the artery-side blood circuit 1 is connected. As shown in FIGS. 2 to 4, the pressure detection unit 7 is formed at a connection portion with the arterial blood circuit 1 (extracorporeal circulation circuit) and is inclined at a predetermined angle toward the blood circulation direction over the entire circumference. In addition to the tapered surfaces 7aa and 7ba, the cross section in the radial direction of the flow path α through which blood can circulate is circular (or may be oval).

  More specifically, the pressure detection unit 7 according to the present embodiment is connected to the upstream side of the arterial blood circuit 1 (extracorporeal circuit) to introduce blood to the inlet side connection unit 7a and the artery. Connected to the downstream side of the side blood circuit 1 (extracorporeal circuit) and connected to the outlet 7b for leading out blood, and connected to these connections 7a and 7b. Accordingly, it has a response portion 7c that can be displaced in the radial direction. That is, the response part 7c is interposed between the connection part 7a on the inlet side and the connection part 7b on the outlet side.

  The connecting portion 7a on the inlet side is formed with a connecting portion 7ab to which a flexible tube constituting the arterial blood circuit 1 is inserted and connected, and is predetermined in the blood circulation direction over the entire circumference. A tapered surface 7aa that is gently inclined at an angle is formed. In addition, the connecting portion 7b on the outlet side is formed with a connecting portion 7bb to which a flexible tube constituting the arterial blood circuit 1 is inserted and connected, and is directed to the blood circulation direction over the entire circumference. Thus, a tapered surface 7ba that is gently inclined at a predetermined angle is formed. That is, the flow path α through which blood can flow in the pressure detection unit 7 is communicated with the flow path of the arterial blood circuit 1 through the tapered surface 7aa on the upstream side and the tapered surface 7ba on the downstream side.

  In addition, the pressure detection unit 7 according to the present embodiment is configured such that the connection part 7a and the response part 7c on the inlet side are integrally formed by injection molding, and the connection part 7b on the outlet side is formed by injection molding. These parts are configured by adhering them with an organic solvent (for example, cyclohexane). In addition, the connection part 7a on the inlet side, the response part 7c and the connection part 7b on the outlet side are molded and bonded by injection molding, respectively, or the connection part 7a on the inlet side, the response part 7c and the outlet side The connecting portion 7b may be integrally formed.

  Furthermore, in the pressure detection unit 7 according to the present embodiment, the response unit 7c is set to be more easily bent in the radial direction than the connection units 7a and 7b. Specifically, the response portion 7c and the connection portion 7a on the introduction port side are integrally formed, and the response portion 7c is set smaller than the thickness of the connection portion 7a on the introduction port side (for example, about 1 to 2 mm thinner). In addition, the response portion 7c is formed of a softer material than the connection portion 7b on the outlet side. For example, the material of the connecting portion 7a and the responding portion 7c on the inlet side is soft PVC (polyvinyl chloride), and the material of the connecting portion 7b on the outlet side is a high degree of polymerization (for example, higher resilience) P = 1700-2500) soft PVC (polyvinyl chloride).

  Thus, by setting the response portion 7c to be more easily bent in the radial direction than the connection portions 7a and 7b, stable responsiveness and shape restoration can be obtained. That is, since both ends of the response portion 7c are supported by the connection portions 7a and 7b that are not easily bent in the radial direction, the response portion 7c can be favorably displaced in the radial direction, and the response portion 7c after the displacement can be It is possible to return to the original state smoothly and reliably.

  In particular, in the present embodiment, the response portion 7c and the connection portion 7a are integrally formed, and the response portion 7c is set smaller than the thickness of the connection portion 7a. 7c can be set to be more easily bent in the radial direction, so that stable responsiveness and shape restoration can be obtained. In addition, in the present embodiment, since the response portion 7c is formed of a softer material than the connection portion 7b, the response portion 7c is more reliably set to be more flexible in the radial direction than the connection portion 7b. Therefore, stable responsiveness and shape restoration can be obtained.

  It is assumed that the connecting portion 7a on the inlet side, the connecting portion 7b on the outlet port side, and the response portion 7c are integrally formed, and the response portion 7c is the meat of the connecting portion 7a on the inlet side and the connecting portion 7b on the outlet side. The connecting portion 7a on the inlet side, the connecting portion 7b on the outlet side, and the response portion 7c are made of different members, respectively, and the response portion 7c is connected to the connecting portion 7a on the inlet side and It is good also as what was shape | molded with the softer material than the connection part 7b by the side of an outlet.

  However, the response portion 7c according to the present embodiment has a substantially uniform thickness over the entire circumference, and is more stable when displaced in the radial direction according to the pressure in the extracorporeal circuit. It is supposed to be possible. That is, when the thickness of the response portion 7c is not uniform in the circumferential direction, when a pressure change occurs in the extracorporeal circuit, the response portion 7c is displaced in various directions according to the thickness, and the displacement is unstable. On the other hand, if the response portion 7c has a substantially uniform thickness over the entire circumference as in the present embodiment, when the pressure change occurs in the extracorporeal circuit, it is displaced substantially uniformly in the circumferential direction. Therefore, stable displacement can be achieved.

  Furthermore, in this embodiment, the taper surface 7aa or the taper surface 7ba is formed so that the inner diameter expands substantially uniformly over the entire circumferential direction. Thereby, it can be made into the shape which further reduced the residence part of the blood as much as possible, and it can suppress more reliably that the thrombus will arise in the blood of an extracorporeal circulation process. The gradient angle of the tapered surface 7aa is preferably 20 to 60 °, and the gradient angle of the tapered surface 7ba is preferably about 20 to 90 °.

  Furthermore, in this embodiment, the tapered surface 7aa on the inlet side where blood is introduced from the extracorporeal circuit is more tapered than the tapered surface 7ba on the outlet side where blood is led out to the extracorporeal circuit. The gradient angle is set to be small (that is, the gradient is gentle). The reason for setting in this way is that flow separation tends to occur at the portion where the flow path diameter is enlarged (inlet side), and it is necessary to reduce the gradient angle of the tapered surface 7aa in order to reduce the staying portion. This is because the separation of the flow is unlikely to occur at the portion where the path diameter is reduced (outlet side), and the gradient angle of the tapered surface 7ba can be increased. Therefore, by reducing the gradient angle of the tapered surface 7aa on the inlet side and increasing the gradient angle of the tapered surface 7ba on the outlet side, the size of the pressure detector 7 (particularly, while reducing the blood retention portion as much as possible). (Longitudinal dimension) can be reduced.

Next, response evaluation according to the present embodiment will be described.
Various values of negative pressure are applied to the pressure detection unit (example) according to the present embodiment and the comparative example having no feature of the present invention, and the thickness (specifically, depending on the pressure). The outer diameter of the response part of the word displaced in the radial direction was measured. In addition, an Example is a pressure detection part of the structure shown in FIGS. 2-4, and a comparative example is a pressure detection part of the structure shown in FIG. As a result, as shown in FIG. 5, it was found that the responsiveness of the example was better than that of the comparative example, particularly in the region of 300 (mmHg) or more.

  According to the above embodiment, the radial section of the response portion 7c and the connection portions 7a and 7b is circular or elliptical, and the inner diameter of the response portion 7c is larger than the inner diameter of the connection portions 7a and 7b. 7b have tapered surfaces 7aa and 7ba that are inclined so that the inner diameter gradually increases toward the response portion 7c, so that a blood thrombus is formed in the blood in the extracorporeal circulation process by making the shape of the blood retention portion as small as possible. It can suppress that it arises.

  Further, according to the present embodiment, the connection portions 7a and 7b having the tapered surfaces 7aa and 7ba and the connection portions 7a and 7b are connected to the extracorporeal circulation circuit, and are connected to the pressure in the extracorporeal circulation circuit. Accordingly, since the response portion 7c that can be displaced in the radial direction is provided, the characteristics of the connection portions 7a, 7b and the response portion 7c can be made different from each other, and the blood retention portion should be made as small as possible. Thus, it is possible to suppress the formation of thrombus in blood in the extracorporeal circulation process. In addition, according to the said embodiment, the extracorporeal circuit to which the pressure detection part 7 was connected can be provided. That is, according to the extracorporeal circuit of the present invention, it is possible to have an effect that can be achieved by the above embodiment.

  Moreover, according to the said embodiment, not only a negative pressure (negative pressure) but a positive pressure (positive pressure) can be detected. That is, among the displacements in the radial direction of the response portion 7c, by detecting the displacement in which the diameter is increased in addition to the displacement in which the diameter is decreased, the arterial blood circuit 1 (liquid flow path) is positively detected. It can be detected. Thereby, for example, when applied to the blood pump 4 as in the above embodiment, the liquid flow between the arterial blood circuit 1 (the blood pump 4 and the venous puncture needle b) when the blood pump 4 is driven forward. Can be detected, and the positive pressure of the arterial blood circuit 1 (the liquid flow path between the blood pump 4 and the venous puncture needle b) when reversely driven can be detected. .

  As mentioned above, although this embodiment was described, this invention is not limited to this, For example, as shown to FIGS. 6-8, the ironing tube 1a was connected to connection part 7'b by the side of an outlet. It may be a thing. The pressure detection unit 7 ′ is connected to the upstream side of the arterial blood circuit 1 (extracorporeal circuit) to introduce blood to the inlet 7a, and the arterial blood circuit 1 (extracorporeal circuit). The connecting portion 7'b on the outlet side that is connected to the downstream side of the blood and leads out blood, and the connecting portions 7a, 7'b are formed in a radial direction according to the pressure in the arterial blood circuit 1 And a displaceable response portion 7c.

  However, the connecting portion 7a on the inlet side is formed with a connecting portion 7ab to which a flexible tube constituting the arterial blood circuit 1 is inserted and connected, and is directed to the blood circulation direction over the entire circumference. Thus, a tapered surface 7aa gently inclined at a predetermined angle is formed. In addition, the connecting portion 7′b on the outlet side is formed with a connecting portion 7′bb to which the ironing tube 1a connected to the arterial blood circuit 1 is inserted and connected, and the blood extends in the entire circumferential direction. A tapered surface 7b'a is formed which is gently inclined at a predetermined angle toward the flow direction. The gradient angle of the tapered surface 7aa is preferably about 20 to 60 °, and the gradient angle of the tapered surface 7b'a is preferably about 20 to 90 °.

  Also in such other embodiments, the response portion 7c and the connection portion 7a are integrally formed, and the response portion 7c is set to be smaller than the wall thickness of the connection portion 7a, so that the response portion is easier than the connection portion 7a. 7c can be set to be more easily bent in the radial direction, so that stable response and shape restoration can be obtained. In addition, also in this other embodiment, the response portion 7c is formed of a softer material than the connection portion 7′b, and more reliably than the connection portion 7′b, as in the above embodiment. 7c can be set to be more easily bent in the radial direction, so that stable response and shape restoration can be obtained.

Further, in the present embodiment, the response portion 7c is set to be more easily bent in the radial direction than the connection portions 7a and 7b. However, the connection portions 7a and 7b and the response portion 7c have substantially the same flexibility. (made of substantially the same thickness or the same material) it may be.

The cross section in the radial direction of the response part and the connection part is circular or elliptical, the inner diameter of the response part is larger than the inner diameter of the connection part, and the connection part is inclined so that the inner diameter gradually increases toward the response part. The connecting portion on the inlet side into which blood is introduced from the extracorporeal circuit is more tapered than the connecting portion on the outlet side that guides blood to the extracorporeal circuit. As long as the pressure detection unit is set to have a small gradient angle, the pressure detection unit can be applied to ones having different appearance shapes or those having other functions added.

1 Arterial blood circuit (fluid flow path)
1a Ironing tube 2 Vein side blood circuit 3 Dialyzer (blood purifier)
4 Blood pump (squeezing type pump)
5 Arterial side air trap chamber 6 Vein side air trap chamber 7 Pressure detecting portion 7a Inlet port side connecting portion 7aa Tapered surface 7b Outlet port side connecting portion 7ba Tapered surface 7c Response portion

Claims (8)

Two connecting parts connected to an extracorporeal circuit for circulating the patient's blood extracorporeally, and a response part arranged between these connecting parts and displaceable in the radial direction according to the pressure of the extracorporeal circuit In the pressure detector provided,
A cross section in a radial direction of the response part and the connection part is circular or elliptical, an inner diameter of the response part is larger than an inner diameter of the connection part, and the connection part gradually increases in inner diameter toward the response part. The inlet side connecting portion into which blood is introduced from the extracorporeal circulation circuit has a tapered surface inclined so as to expand in diameter , and is closer to the outlet side that leads blood to the extracorporeal circulation circuit. A pressure detection unit characterized in that the inclination angle of the tapered surface is set smaller than that of the connection unit .   The pressure detection unit according to claim 1, wherein the tapered surface is formed so that an inner diameter of the tapered surface expands substantially uniformly over the entire circumferential direction.   The pressure detection unit according to claim 1, wherein the response unit is set to be more easily bent in the radial direction than the connection unit.   The pressure detection unit according to claim 3, wherein the response unit and the connection unit are integrally formed, and the response unit is set smaller than a thickness of the connection unit.   The pressure detection unit according to claim 3, wherein the response unit is formed of a softer material than the connection unit.   The pressure detection unit according to claim 1, wherein the response unit has a substantially uniform thickness over the entire circumference. The inclination angle of the tapered surface of the connecting portion on the inlet side is 20 to 60 °, and the inclination angle of the tapered surface of the connecting portion on the outlet side is 20 to 90 °. The pressure detector according to any one of claims 1 to 6.   An extracorporeal circuit having the pressure detector according to any one of claims 1 to 7 connected thereto.

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