Diaphragm pressure pod for medical fluids
View Patent ↗A tubular medical fluid flow set comprises a pressure sensing chamber connected in flow-through relation to fluid flow tubing of the set. The pressure sensing chamber defines a movable, flexible, impermeable diaphragm dividing the chamber into two separate compartments. The fluid flow tubing communicates with one of the compartments and is isolated from the other of the compartments. A port is carried on the chamber, the port having a seal therein, and communicating with the other of the compartments. Thus, the other of the compartments is hermetically sealed until the port is opened for connection with a pressure measuring device, to keep the flexible diaphragm in a desired, initial position prior to opening of the seal.
1. The method of rinsing blood from an extracorporeal blood flow tube and returning it to the patient after an extracorporeal blood flow procedure, said blood flow tubing connected to a chamber having a flexible diaphragm defining a blood holding volume, said diaphragm being sealingly mounted within said chamber, which method comprises: pressurizing said chamber to move said diaphragm to cause the blood holding volume of said chamber to be substantially minimized, without blocking flow through said blood flow tube and chamber; and causing aqueous solution to pass into said tube and chamber to replace said blood, while returning said blood to the patient.
2. The method of claim 1 in which said chamber was previously used to sense subatmospheric blood pressure in said blood flow tube through a length of pressure tubing connected to said chamber, wherein the diaphragm was initially positioned to essentially maximize the blood holding volume in said chamber.