Measurement of fluid pressure in a blood treatment device

• US 7,147,613 B2
• Filed: 03/08/2004
• Issued: 12/12/2006
• Est. Priority Date: 02/14/1997
• Status: Expired due to Term

• Current Assignee: Nxstage Medical Incorporated (Fresenius Medical Care AG)
• Original Assignee: Nxstage Medical Incorporated (Fresenius Medical Care AG)
• Inventors: Brugger, James M., Treu, Dennis M., Burbank, Jeffrey H.
• Primary Examiner(s): Bianco, Patricia
• Application Number:
  US10/796,787
• Publication Number:
  US 20040267184A1
• Time in Patent Office: 1,009 Days
• Field of Search: 604/4.01, 604/6.01, 604 501- 504, 604/6.04, 604/6.1, 604/6.09, 604/6.11, 604/6.15, 604/6.16, 422 44- 48, 422/82.13, 422105-106, 422/112, 128/898, 128/DIG.3, 128/904, 128/920, 128923- 24, 210645-647, 210650-652, 210/739, 210/741, 210/744, 210/767, 210/782, 210/85, 210/87, 210/97, 210/103, 210/104, 210/252, 210/235, 210/255, 210/256, 210/321.6, 210/321.71, 210/321.72, 210/929, 210/418, 210/416.1
• US Class Current: 604/5.01
• CPC Class Codes: A61M 1/1611 Weight of the patient
• CPC Class Codes: A61M 1/1639 linked by membranes
• CPC Class Codes: A61M 1/34 Filtering material out of the blood by passing it through a membrane, i.e. hemofiltration or diafiltration
• CPC Class Codes: A61M 1/3401 Cassettes therefor
• CPC Class Codes: A61M 1/3403 Regulation parameters
• CPC Class Codes: A61M 1/341 by measuring the filtrate rate or volume
• CPC Class Codes: A61M 1/342 Adding solutions to the blood, e.g. substitution solutions for preventing coagulation A61M1/3672
• CPC Class Codes: A61M 1/3441 Substitution rate control as a function of the ultrafiltration rate
• CPC Class Codes: A61M 1/3444 in which the collected ultra-filtrate expels an equal volume of substitution fluid from a reservoir
• CPC Class Codes: A61M 1/3448 by mechanically linked pumps in both ultra-filtrate and substitution flow line
• CPC Class Codes: A61M 1/3458 having electrolytes not present in the dialysate
• CPC Class Codes: A61M 1/361 before treatment
• CPC Class Codes: A61M 1/3612 after treatment
• CPC Class Codes: A61M 1/362223 the interface being evacuated interfaces to enhance contact
• CPC Class Codes: A61M 1/36224 with sensing means or components thereof
• CPC Class Codes: A61M 1/36225 with blood pumping means or components thereof
• CPC Class Codes: A61M 1/36226 Constructional details of cassettes, e.g. specific details on material or shape
• CPC Class Codes: A61M 1/362262 Details of incorporated reservoirs
• CPC Class Codes: A61M 1/362265 Details of valves
• CPC Class Codes: A61M 1/3626 Gas bubble detectors
• CPC Class Codes: A61M 1/3639 : Blood pressure control, pressure transducers specially adapted therefor
• CPC Class Codes: A61M 1/3646 : Expelling the residual body fluid after use, e.g. back to the body
• CPC Class Codes: A61M 1/367 : Circuit parts not covered by the preceding subgroups of group A61M1/3621
• CPC Class Codes: A61M 2205/126 : with incorporated membrane filters
• CPC Class Codes: A61M 2205/128 : with incorporated valves
• CPC Class Codes: A61M 2205/15 : Detection of leaks
• CPC Class Codes: A61M 2205/3306 : Optical measuring means
• CPC Class Codes: A61M 2205/3331 : Pressure; Flow
• CPC Class Codes: A61M 2205/3334 : Measuring or controlling the flow rate
• CPC Class Codes: A61M 2205/35 : Communication
• CPC Class Codes: A61M 2205/3553 : remote, e.g. between patient's home and doctor's office
• CPC Class Codes: A61M 2205/3569 : sublocal, e.g. between console and disposable
• CPC Class Codes: A61M 2205/502 : User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/505 : Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches
• CPC Class Codes: A61M 2205/60 : with identification means
• CPC Class Codes: A61M 2205/6018 : providing set-up signals for the apparatus configuration
• CPC Class Codes: A61M 2205/6072 : Bar codes
• CPC Class Codes: A61M 39/0208 : Subcutaneous access sites for injecting or removing fluids transcutaneous access sites A61M39/0247; implantable infusion devices A61M5/14276
• CPC Class Codes: Y10S 210/929 : Hemoultrafiltrate volume measurement or control processes

Abstract

A first flow path is defined within a first panel that forms a part of an extracorporeal fluid circuit. A second flow path is defined within a second panel that also forms a part of the extracorporeal fluid circuit. The first and second panels are oriented in a fluid processing cartridge for mounting as an integrated unit on a fluid processing machine and for removal as an integrated unit from the fluid processing machine.

Claims

1. A renal replacement therapy system, comprising:

a blood treatment device;

an extracorporeal fluid circuit including a first panel comprising first and second sheets of flexible material forming a portion of a fluid pathway defined by a pattern of seals;

an in-line sensor region between the two flexible sheets, said sensor region being characterized by an expanded portion of said fluid pathway which has substantially flattened walls defined by said flexible sheets;

said at least one fluid pathway carrying conveying fresh fluid for consumption by a blood treatment component and waste fluid from said blood treatment component;

the at least one fluid pathway, including said expanded portion, being free of an air interface;

the blood treatment device including a sensor physically contacting a non-wetted surface of said expanded portion to measure fluid pressure within said first when said fluid;

said extracorporeal fluid circuit including a blood circuit portion adapted to circulate blood from an individual through the blood treatment component to treat it and to return treated blood to the individual.

2. A system according to claim 1 wherein the first panel includes an in-line pump region to convey fluid in the flow channel in response to peristaltic pressure externally applied to the flexible panel.

3. A system according to claim 2 wherein the in-line sensor region is located in an upstream flow direction from the in-line pump region.

4. A system as in claim 1, wherein said blood treatment device includes recesses that define a chamber, said first panel includes a chamber portion in fluid communication with said in-line sensor region that is expanded by said blood treatment device to fill said recesses, whereby said chamber portion defines a fixed volume chamber.

5. A system as in claim 1, wherein said sensor includes a strain gage type pressure sensor.

6. A system as in claim 1, wherein said sensor region has a non-circular cross-section.

7. A renal replacement therapy system, comprising:

a blood treatment device having a pressure sensor region;

a fluid circuit;

said fluid circuit including at least one panel defined by flexible panel walls in which fluid flows between said flexible walls;

said fluid circuit being configured to be engaged by said blood treatment device including engaging a portion of said flexible panel walls by said pressure sensor region such that a pressure within said at least one panel is measurable by a force of said fluid against said pressure sensor region when said fluid circuit is engaged by said blood treatment device;

said pressure sensor region remaining outside, in contact with a non-wetted surface of said at least one panel, said at least one panel such that no fluid-air interface is required;

said fluid circuit including a treatment filter portion a sterile portion including a venous line adapted for conveying blood to a patient from said treatment filter portion and from an arterial portion adapted for conveying blood from a patient to a treatment filter portion;

said fluid circuit and said pressure sensor region being configured such that at least one of a pressure of a venous pressure, an arterial pressure, and a pressure of blood at said treatment filter portion is indicated by said pressure sensor region.