Method and apparatus for aspirating and dispensing sample fluids
First Claim
1. An apparatus for aspirating and dispensing a sample fluid comprising:
- a dilutor having a port;
a bleed valve having a first port and a second port;
a flow through pressure transducer, having a first port and a second port, said transducer operative to provide a pressure signal;
a connecting member having a first port, a second port, and a third port in mutual fluid communication, wherein the first port is coupled to the port of said dilutor, the second port is coupled to the first port of said bleed valve, and the third port is coupled to the first port of said flow through pressure transducer;
a sample probe having a first port coupled to the second port of said flow through pressure transducer; and
a controller in communication with said dilutor, said bleed valve, and said flow through pressure transducer, said controller operative to control said dilutor and said bleed valve in response to said pressure signal.
3 Assignments
0 Petitions
Accused Products
Abstract
A method and apparatus for aspirating and dispensing a sample fluid. The apparatus includes a dilutor having a port coupled to a first port of a flow through pressure transducer and to a bleed valve. A second port of the flow through pressure transducer is coupled to a first port of a sample probe. The flow through pressure transducer provides transducer signals to a detector circuit. In response to the transducer signals provided thereto, the detector detects the occurrence or non-occurrence of a plurality of different events. The dilutor is operational to aspirate and dispense fluids such as air or liquid samples in order to provide accurate aspiration and dispensation of a sample fluid. The method includes the steps of first aspirating a predetermined amount of air with the dilutor, dispensing air while moving the sample probe towards the fluid sample, measuring the pressure in the probe and using this pressure value as a baseline, monitoring the pressure and detecting when the pressure changes, which is indicative of the probe entering the fluid sample, bleeding the pressure into the atmosphere while returning the dilutor to its home position, aspirating a predetermined amount of fluid to remove dilutor backlash, waiting a predetermined amount of time to finish bleeding the system, then aspirating the fluid sample with the dilutor. With such a method and apparatus, accurate aspirations/dispensations are provided, especially when small volumes are required.
190 Citations
14 Claims
-
1. An apparatus for aspirating and dispensing a sample fluid comprising:
-
a dilutor having a port; a bleed valve having a first port and a second port; a flow through pressure transducer, having a first port and a second port, said transducer operative to provide a pressure signal; a connecting member having a first port, a second port, and a third port in mutual fluid communication, wherein the first port is coupled to the port of said dilutor, the second port is coupled to the first port of said bleed valve, and the third port is coupled to the first port of said flow through pressure transducer; a sample probe having a first port coupled to the second port of said flow through pressure transducer; and a controller in communication with said dilutor, said bleed valve, and said flow through pressure transducer, said controller operative to control said dilutor and said bleed valve in response to said pressure signal. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A method for aspirating and dispensing a sample fluid comprising the steps of:
-
aspirating a first volume of air with a dilutor; dispensing with the dilutor at least a portion of said first volume of air through a sample probe in fluid communication with the dilutor while moving the sample probe towards a target sample fluid volume; measuring the pressure in the sample probe using a transducer; storing a value of the measured pressure in a detection circuit; monitoring the pressure in the sample probe using said transducer; detecting, with said detection circuit, a pressure increase as the sample probe enters the sample fluid volume; comparing, using the detection circuit, the difference between the stored pressure value and the currently monitored pressure to a threshold value to determine the detection of the sample fluid; stopping movement of the sample probe upon detection of the pressure increase as the sample probe enters the sample fluid; bleeding pressurized air from the sample probe while returning the dilutor to a home position; aspirating a second volume of air with the dilutor; waiting a predetermined period of time; and aspirating said sample fluid with the dilutor. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
-
Specification