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US 5,185,084 AGranted
Method and apparatus for control of flow through a filter chamber by measured chamber equilibration pressure
AssigneeCytyc Corporation
InventorsStanley N. Lapidus, Dean Kamen, Richard R. Villeneuve, Lewis T. Polk, Jr.
Life of this patent
Estimating the term…
Abstract
A method and apparatus for the controlled instrumentation processing of cells and other paricles with a filter device measures a parameter of the flow through the filter device of a fluid carrying the particles. A measure of the change of fluid flow through the filter device yields desired information for quantizing the particles and for quantizing the obstruction of the filter device by the particles. The method and apparatus typically operate automatically.
Claims7
Apparatus for supplying a selected sequence of pressure conditions to a filter device for controlling the flow of particle-containing fluid through the filter device, said apparatus comprising
- A. means forming a filter chamber having pressure port means and having a filter device forming a chamber wall thereof and having a porosity for blocking particles of selected size, said filter chamber being arranged for fluid to flow into the interior thereof through said filter device,
- B. pressure source means arranged with valve means for selectively applying a source pressure to said chamber interior by way of said pressure port means, said source pressure being different from a first pressure in said filter chamber and producing a flow of fluid greater than any flow occurring during presence of said first pressure, and
- C. control means arranged for sensing the chamber interior pressure and connected with said valve means, said control means being arranged for executing a cycle of successive operations including
- (i) a first step of opening said valve means for applying said source pressure to said chamber interior for producing a selected fluid flow through said filter device,
- (ii) a second step of closing said valve means for allowing a flow of fluid through said filter device for equilibrating the chamber pressure in a direction from said source pressure toward said first interior pressure,
- (iii) a third step of measuring an equilibration time in which said chamber pressure equilibrates from said source pressure to a second chamber pressure intermediate said first pressure and said source pressure, said equilibration time corresponding to a degree of blockage of said filter device by the particles, and
- (iv) repeating said first and second and third steps only in response to an equilibration time, as measured in said third step, less than a predetermined time value.
4 more elements
Apparatus for measuring the occlusion of a filter device by particles contained in a fluid flowing through the filter device, said apparatus comprising
- A. means forming a filter chamber having a filter device forming a chamber wall thereof and having a porosity for blocking particles of selected size, said filter chamber being arranged for fluid to flow into the interior thereof through said filter device,
- B. pressure source means arranged with valve means for selectively applying a flow-producing pressure differential across said filter device, said flow-producing pressure differential being different from a first pressure differential across said filter device and producing a flow of fluid greater than any flow occurring during presence of said first pressure differential, and
- C. control means arranged for sensing a pressure differential across said filter device and connected with said valve means, said control means being arranged for executing a cycle of successive operations including
- (i) a first step of opening said valve means for applying said flow-producing pressure differential across said filter device for producing a selective fluid flow through said filter device,
- (ii) a second step of closing said valve means for allowing a flow of fluid through said filter device for equilibrating the pressure differential in a direction from said flow-producing pressure differential toward said first pressure differential,
- (iii) a third step of measuring an equilibration time in which said pressure differential equilibrates from said flow-producing pressure differential to an equilibration pressure differential intermediate said first pressure differential and said equilibration pressure differential, and
- (iv) repeating said first and second and third steps only in response to an equilibration time, as measured in said third step, less than a predetermined time value.
4 more elements
A method for supplying a selected sequence of pressure conditions to a filter device for controlling the flow of particle-containing fluid through the filter device, said method comprising
- A. providing a filter chamber having pressure port means and having a filter device forming a chamber wall thereof and having a porosity for blocking particles of selected size, said filter chamber being arranged for fluid to flow into the interior thereof through said filter device,
- B. providing a pressure source arranged with valve means for selectively applying a source pressure to said chamber interior by way of said pressure port means, said source pressure being different from a first pressure in said filter chamber and producing a flow of fluid greater than any flow occurring during presence of said first pressure,
- C. providing control means arranged for sensing the chamber interior pressure and connected with said valve means,
- D. operating said control means through a cycle of successive operations including
- (i) a first step of opening said valve means for applying said source pressure to said chamber interior for producing a selected fluid flows through said filter device,
- (ii) a second step of closing said valve means for allowing a flow of fluid through said filter device for equilibrating the chamber pressure in a direction from said source pressure toward said first interior pressure,
- (iii) a third step of measuring an equilibration time in which said chamber pressure equilibrates from said source pressure to a second chamber pressure intermediate said first pressure and said source pressure, and
- (iv) repeating said first and second and third steps only in response to an equilibration time, as measured in said third step, less than a predetermined time value.
5 more elements
Dependencies are inferred from the claim text.