Method of operating a fluid flow transfer device

• US 4,770,787 A
• Filed: 02/11/1987
• Issued: 09/13/1988
• Est. Priority Date: 06/25/1985
• Status: Expired due to Term

• Current Assignee: Gambro, Inc. (DaVita Incorporated)
• Original Assignee: Cobe Cardiovascular Incorporated (LivaNova Plc)
• Inventors: Palsulich, William G., Manica, Keith J., Heath, Gary B., Swan, Jack C. Jr.
• Primary Examiner(s): Fisher, Richard V.
• Assistant Examiner(s): JONES, WILLIAM G
• Application Number:
  US07/013,355
• Time in Patent Office: 580 Days
• Field of Search: 210/90, 210/137, 210/206, 210/239, 210/232, 210/321.2, 210/321.3, 210/321.4, 210/416.1, 210/433.2, 210/645, 210/646, 210/741, 210/764, 210/321.72 , 210/321.74, 210/321.75, 210/321.78, 210/321.79, 210/321.8, 210/321.81, 604/4
• US Class Current: 210/646
• CPC Class Codes: A61M 1/3621 Extra-corporeal blood circuits single-needle circuits A61M1/30
• CPC Class Codes: A61M 1/36222 Details related to the interface between cassette and machine
• 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 1/362264 the filter being a blood filter
• CPC Class Codes: A61M 1/362266 Means for adding solutions or substances to the blood
• CPC Class Codes: A61M 1/3639 Blood pressure control, pressure transducers specially adapted therefor
• CPC Class Codes: A61M 1/3641 Pressure isolators
• CPC Class Codes: A61M 1/3643 Priming, rinsing before or after use
• CPC Class Codes: A61M 1/3644 Mode of operation
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/125 with incorporated filters

Abstract

A fluid flow chamber cassette that can be mounted with either its front wall or rear wall against a supporting machine and has a flexible tube that extends from a sidewall and forms a loop that is symmetrical about a loop axis that is transverse to the side wall so that the loop will be acted upon by a pump roller on the machine both when the front wall is against the machine and when the rear wall is against the machine. Also disclosed is automatically fixing the initial liquid levels and amounts of air in venous and arterial chambers of fluid flow transfer device apparatus by having the arterial chamber inlet enter the arterial chamber at a position higher than the arterial chamber outlet, having the venous chamber inlet enter the venous chamber at a position higher than the venous chamber outlet, and priming the apparatus by causing reverse flow, so that the liquid rises in the venous and arterial chambers to the level of the entrances of the inlets. Also disclosed is sensing pressure of fluid in a fluid flow chamber by placing an impermeable flexible diaphragm over a hole in a rigid wall of the fluid flow chamber, providing a second chamber on the other side of the diaphragm, and sensing the pressure in the second chamber.

Claims

1. A method of operating fluid flow transfer apparatus, said method comprising

providing a fluid flow transfer device, an arterial chamber, and a venous chamber, an inlet of said fluid flow transfer device being connected to an outlet of said arterial chamber, an outlet of said fluid flow transfer device being lower than said inlet of said transfer device and being connected to an inlet to said venous chamber, said arterial chamber having an inlet entering said arterial chamber at a position higher than said arterial chamber outlet, said venous chamber inlet entering said venous chamber at a position higher than an outlet of said venous chamber, and

priming a blood flow path of said apparatus by pumping sterile priming solution through said venous chamber, fluid flow transfer device and arterial chamber in the opposite direction from normal operation of said apparatus, namely into said outlet of said venous chamber, whereby said sterile solution rises in said venous chamber to the level of the entrance of said venous chamber inlet, flows upward through said fluid flow transfer device, removing air bubbles in it, and into said arterial chamber, rising in said arterial chamber to the level of the entrance of said arterial chamber inlet, whereby the initial liquid levels and amounts of air in said arterial and venous chambers are automatically fixed at predetermined levels and amounts.

2. The method of claim 1 further comprising connecting the inlet of said arterial chamber to a patient, pumping in the direction opposite to that during said priming until said sterile solution in said apparatus has been replaced by blood, connecting the outlet of said venous chamber to said patient and continuing pumping in the same direction to cause transfer in said device.

3. The method of claim 2 further comprising sensing the pressure in said arterial and venous chambers during said continuing pumping.

4. The method of claim 3 further comprising connecting said inlet of said arterial chamber to a sterile solution, pumping to return blood to said patient, disconnecting said patient, turning said device and arterial and venous chambers upside down, and pumping disinfecting solution through said venous chamber outlet and through all regions in the blood flow path of said apparatus.