Blood circuit having pressure measurement portion

Patent metadata

Field	Value
Publication number	US-2017319086-A1
Application number	US-201515522642-A
Country	US
Kind code	A1
Filing date	Oct 28, 2015
Priority date	Oct 28, 2014
Publication date	Nov 9, 2017
Grant date	—

Abstract

A blood circuit having a pressure measurement portion connected to a pressure measurement device includes: a first measurement portion provided downstream of a pumping segment; and a second measurement portion provided upstream of the pumping segment. The first measurement portion includes: a first housing having a tubular shape; and a first flexible membrane having a tubular shape and provided in the first housing. The second measurement portion includes: a second housing having a tubular shape; and a second flexible membrane having a tubular shape and provided in the second housing. A space between the first flexible membrane and the first housing is larger than a space between the second flexible membrane and the second housing in an initial state before permitting the blood to flow.

First claim

1 . (canceled)

2 . (canceled)

3 . A blood circuit having a pressure measurement portion connected to a pressure measurement device, the blood circuit comprising:
a housing having a tubular shape; and a flexible membrane having a tubular shape and provided within the housing having the tubular shape, the flexible membrane being provided close to the housing, pressure fluctuation of blood being able to be measured by permitting the blood to flow in a tube of the flexible membrane to deform the flexible membrane in a tube inward direction according to pressure of the blood to increase a space between the flexible membrane and the housing.

4 . The blood circuit having the pressure measurement portion according to claim 3 , wherein the flexible membrane has a cylindrical shape to have an inner diameter and an outer diameter each constant in an axial direction in an initial state before permitting the blood to flow.

5 . The blood circuit having the pressure measurement portion according to claim 4 , wherein
in the initial state before permitting the blood to flow, the flexible membrane has a cross section with a substantially exactly circular shape, and the housing has a cylindrical shape to have a cross section with a substantially exact circular shape to have an inner diameter and an outer diameter each constant in the axial direction.

6 . The blood circuit having the pressure measurement portion according to claim 4 , wherein
when X represents an axial length of a deformable portion of the flexible membrane in the initial state before permitting the blood to flow and Y represents an outer diameter of the deformable portion of the flexible membrane in the initial state before permitting the blood to flow, the axial length X and the outer diameter Y satisfy 4.0≦X/Y≦8.0, when T represents a thickness of the deformable portion of the flexible membrane in the initial state before permitting the blood to flow, the thickness T satisfies 0.2 mm≦T≦0.6 mm, and the flexible membrane has a Shore A hardness of not less than 20 and not more than 60.

7 . The blood circuit having the pressure measurement portion according to claim 3 , the blood circuit further comprising:
a first joint component attached to one end of the housing in an axial direction; and a second joint component attached to the other end of the housing in the axial direction, wherein an end portion of the flexible membrane having the tubular shape is fixed by sandwiching the end portion of the flexible membrane between the housing and at least one of the first joint component and the second joint component in the axial direction.

8 . The blood circuit having the pressure measurement portion according to claim 7 , wherein
one end portion of the flexible membrane having the tubular shape is fixed by sandwiching the one end portion of the flexible membrane between the first joint component and the housing in the axial direction, and the other end portion of the flexible membrane having the tubular shape is fixed by sandwiching the other end portion of the flexible membrane between the second joint component and the housing in a radial direction.

9 . A blood circuit having a pressure measurement portion connected to a pressure measurement device, the blood circuit comprising:
a housing having a tubular shape; and a flexible membrane having a tubular shape and provided in the housing having the tubular shape with a space being formed between the housing and the flexible membrane, the flexible membrane having a cross section at least a portion of which is non-circular, pressure fluctuation of blood being able to be measured by permitting the blood to flow in a tube of the flexible membrane to deform a non-circular portion of the flexible membrane in a tube outward direction according to pressure of the blood to decrease the space between the housing and the flexible membrane.

10 . The blood circuit having the pressure measurement portion according to claim 9 , wherein a plurality of recesses are formed in a surface of the flexible membrane and extend in parallel with one another.

11 . The blood circuit having the pressure measurement portion according to claim 10 , wherein in an initial state before permitting the blood to flow, in a cross section of a deformable portion of the flexible membrane, an outer circumferential edge of the flexible membrane has a length equal to or less than a length of an inner circumferential edge of the housing, the cross section being orthogonal to an axial direction of the housing.

12 . The blood circuit having the pressure measurement portion according to claim 10 , wherein the number of the recesses is 2 to 4.

13 . The blood circuit having the pressure measurement portion according to claim 11 , wherein the flexible membrane is configured to have an inner circumferential surface not contacted at any portion in the initial state before permitting the blood to flow.

14 . The blood circuit having the pressure measurement portion according to claim 9 , wherein in the initial state before permitting the blood to flow, each of cross sectional areas in the tube of the flexible membrane at both end portions of a deformable portion of the flexible membrane is larger than a cross sectional area in the tube of the flexible membrane at a central portion of the deformable portion of the flexible membrane.

15 . The blood circuit having the pressure measurement portion according to claim 14 , wherein in the initial state, a cross sectional area in the tube of the flexible membrane becomes gradually smaller in a direction from each of the both end portions to the central portion.

16 . The blood circuit having the pressure measurement portion according to claim 9 , the blood circuit further comprising:
a first joint component attached to one end of the housing in an axial direction; and a second joint component attached to the other end of the housing in the axial direction, wherein an end portion of the flexible membrane having the tubular shape is fixed by sandwiching the end portion of the flexible membrane between the housing and at least one of the first joint component and the second joint component in the axial direction.

17 . The blood circuit having the pressure measurement portion according to claim 16 , wherein
one end portion of the flexible membrane having the tubular shape is fixed by sandwiching the one end portion of the flexible membrane between the first joint component and the housing in the axial direction, and the other end portion of the flexible membrane having the tubular shape is fixed by sandwiching the other end portion of the flexible membrane between the second joint component and the housing in a radial direction.

18 . A blood circuit having a pressure measurement portion connected to a pressure measurement device, the blood circuit comprising:
a housing having a tubular shape and having one end and the other end in an axial direction; a flexible membrane having a tubular shape and provided in the housing having the tubular shape; a first joint component attached to the one end of the housing; and a second joint component attached to the other end of the housing, pressure fluctuation of blood being able to be measured by permitting the blood to flow in a tube of the flexible membrane to displace the flexible membrane according to pressure of the blood, an end portion of the flexible membrane having the tubular shape being fixed by sandwiching the end portion of the flexible membrane between the housing and at least one

Assignees

• Nipro Corp

Inventors

• Masuda Toshiaki
• Yamaguchi Takeshi

Classifications

• A61B5/026

  Measuring blood flow {(A61B3/1233, A61B3/1241 take precedence)} · CPC title

• A61B5/02141

  Details of apparatus construction, e.g. pump units or housings therefor, cuff pressurising systems, arrangements of fluid conduits or circuits (A61B5/02233, A61B5/0235 take precedence) · CPC title

• A61B5/02007

  Evaluating blood vessel condition, e.g. elasticity, compliance · CPC title

• A61M2205/3331

  Pressure; Flow · CPC title

• A61M1/3639 Primary

  Blood pressure control, pressure transducers specially adapted therefor · CPC title