Abstract: The present invention concerns devices for receiving and processing a sample. The device comprises a sample receiving element adapted to establish fluid communication with and receive a sample directly from a sample container. The sample receiving element also allows for introduction of a sample into the device. A first chamber is in fluid communication with the sample receiving element. One or more second chambers are in fluid communication with the first chamber. The device also comprises first and second ports. The first port provides for venting the device. The second port provides for establishing communication between the device and means for moving the sample from the sample receiving element to the first chamber and for moving the sample from the first chamber to the one or more second chambers. Also included as part of the device is means for controlling the precise amount of the sample introduced into each of the second chambers.

Abstract: A method for testing for patency at a venous access site during intravenous infusion of a medical solution includes the steps of occluding an intravenous injection tube upstream from the venous access site and monitoring the time and fluid pressure within the tube while the fluid pressure within the tube is varied by external contact with the tube. An apparatus for practicing the method of the invention includes a housing formed with a tube receiving portion for holding a portion of the tube in contact with an occluder finger, a fluid moving finger and a pressure transducer. The fluid moving finger is adapted to contact the tube so as to achieve a testing base pressure in the fluid, after occlusion by the occluder finger. A sequence of pressure drops are then effected by moving the fluid moving finger in stepped increments.

Abstract: A linear peristaltic pump includes a mechanism for maintaining linear flow of fluid through an I.V. tube. The mechanism comprises a casing carrying a rotatable camshaft having a plurality of cams spaced therealong in helical arrangement and a plurality of fingers coupled to the camshaft. A housing for establishing linear reciprocal movement of the fingers in response to rotation of the shaft establishes a moving zone of occlusion along a tube held against the fingers. Aligning means are included for establishing an axis of rotation of the camshaft which is slightly tilted with respect to the tube. This is accomplished by raising or lowering the upstream or the downstream end of the camshaft to prevent unwanted pressure from building up in the tube to reduce pulsatile flow and maintain linear flow. The aligning mechanism comprises a generally cylindrical bushing having an eccentric hole therethrough for carrying the hinged connection between the casing and the housing.

Abstract: A linear peristaltic pump equipped with a pressure relief mechanism for pumping I.V. fluids to a patient comprises a platen for supporting the tube, and a plurality of fingers which sequentially urge against the tube resting against the platen for creating a moving zone of occlusion. Cam lobes are formed to lift a penultimate and ultimate finger off of the tube at a rate faster than the other fingers to prevent pressure increases inside the tube which would otherwise be caused by other fingers urging against the tube. Additionally, the ultimate finger may be shortened with respect to the other fingers to reduce the total occlusion time of the ultimate finger to provide a more linearized flow of fluid to the patient.