초록 ▼

A method for dynamically determining the volume of a liquid dispensed by a metering system, the metering system including a metering pump, a pump motor, a sensor, and a conduit interconnecting the pump and a metering probe. The method includes the steps of aspirating a quantity of fluid into the met

A method for dynamically determining the volume of a liquid dispensed by a metering system, the metering system including a metering pump, a pump motor, a sensor, and a conduit interconnecting the pump and a metering probe. The method includes the steps of aspirating a quantity of fluid into the metering probe using the metering pump, moving the probe relative to a reaction vessel, and dispensing the fluid. The dispensing step includes the steps of identifying an onset point associated with a parameter which can be measured by the metering system, identifying an end point associated with the measurable parameter, and timing the pump motor during the period between the onset point and the end point in order to determine fluid volume. The sensor, such as a pressure transducer or capacitance change sensor, disposed in relation to the conduit can detect changes in the parameter and identify the onset and end points.

대표청구항 ▼

We claim: 1. A method for dynamically determining the volume of a liquid dispensed by a metering system, said metering system including a metering pump, a metering probe, a conduit between said metering probe and said metering pump, a pump motor and at least one sensor disposed in relation to said

We claim: 1. A method for dynamically determining the volume of a liquid dispensed by a metering system, said metering system including a metering pump, a metering probe, a conduit between said metering probe and said metering pump, a pump motor and at least one sensor disposed in relation to said conduit for measuring a parameter of said metering system, said pump motor having a positive displacement element, said method including the steps of: aspirating a quantity of liquid into said metering probe using said metering pump; moving said metering probe relative to a reaction vessel; and dispensing the quantity of liquid onto said reaction vessel, said dispensing step including the steps of: monitoring said parameter continuously using said at least one sensor, each said at least one sensor producing a parameter profile; identifying an onset point associated with said parameter which can be measured by said at least one sensor, said onset point being determined by a first detectable change of said parameter in said parameter profile; identifying an end point associated with said parameter, said end point being determined by a second detectable change in said parameter profile, thereby defining a specific time period; and measuring the displacement of said positive displacement element of said metering pump during the time period between said identified onset point and said identified end point, wherein said measurement provides a determination of dispensed liquid volume, wherein said at least one sensor includes at least one pressure transducer for measuring pressure changes in said metering probe and producing a pressure profile, said onset point relating to a change in said pressure profile indicative of a reduction in pressure in said metering probe that is further indicative of a meniscus of dispensed liquid first contacting said reaction vessel and the end point relating to an abrupt reduction in pressure according to said pressure profile occurring after the entire quantity of liquid has been dispensed from the metering probe. 2. A method as recited in claim 1, wherein said pump motor is a stepper motor, said measuring step including the step of counting the number of pulses of said pump motor between said onset point and said end point wherein each said pulse equates to a predetermined liquid quantity. 3. A method as recited in claim 1, wherein said reaction vessel is a slide element. 4. A method for dynamically determining the volume of a wash liquid dispensed by a metering system onto an immuno-rate slide element, said metering system including a metering pump, a pump motor and at least one sensor capable of continuously measuring a parameter of said metering system, said method including the steps of: aspirating a quantity of wash liquid into a metering probe using said metering pump; moving said metering probe relative to said slide element; and dispensing the quantity of liquid onto said slide element said dispensing step including the steps of: identifying an onset point associated with a parameter which can be measured by said metering system by identifying a first detectable change in a monitored parameter profile as measured by said at least one sensor; identifying an end point associated with said parameter by identifying a second detectable change in a monitored parameter profile as measured by said at least one sensor, thereby defining a specific time period; and counting the number of pulses of said pump motor, wherein each pulse of said pump motor is indicative of the dispensing of a predetermined amount of liquid, and totaling the number of pulses during the period between said identified onset point and said identified end point to determine total liquid volume during that period wherein said at least one sensor includes at least one pressure transducer for measuring pressure changes in said metering prone, said at least one pressure transducer measuring a first pressure change in said metering probe indicative of said identified onset point and a second pressure change in said metering probe indicative of said identified end point, wherein said first pressure change is indicative of a meniscus of liquid first contacting said slide element from said metering probe and said second pressure change is indicative of an abrupt reduction in pressure occurring after all liquid has been dispensed from said metering probe. 5. A method as recited in claim 4, wherein said metering system includes a conduit between said metering probe and said metering pump and said at least one sensor is disposed relative to said conduit for measuring said parameter.