The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 12, 2012
Filed:
Jan. 23, 2009
Tien-shoe Wang, Methuen, MA (US);
David W. Mcgill, Bedford, NH (US);
Dean Kamen, Bedford, NH (US);
DEKA Products Limited Partnership, Manchester, NH (US);
Abstract
A volume of fluid moved by a pump, such as a pump in an APD system, may be determined without direct measurement of the fluid, such as by flow meter, weight, etc. For example, a volume of a pump chamber () (having a movable element that varies the volume of the pump chamber) may be determined by measuring pressure in the pump chamber and a reference chamber, both while the two chambers are isolated from each other, and after the two chambers are fluidly connected so that pressures in the chambers may equalize. Equalization of the pressures may be assumed to occur in an adiabatic way, e.g., a mathematical model of the system that is based on an adiabatic pressure equalization process may be used to determine the pump chamber volume. In one embodiment, pressures measured after the chambers are fluidly connected may be measured at a time before complete pressure equalization has occurred, and thus the pressures for the pump and reference chambers measured after the chambers are fluidly connected may be unequal, yet still be used to determine the pump chamber volume.