Abstract: A method for determining a condition in a blood sample includes: providing a sample of blood; providing a metering probe having a pump for aspirating and dispensing; inserting the metering probe a selected distance into the blood sample; measuring the pressure between the sample and pump during sample aspiration or sample dispense; comparing the measured pressure with a reference value; and signaling the presence or absence of the condition. A method for confirming or detecting the presence of a selected layer of blood component in a centrifuged blood sample includes: measuring a pressure of a suspected selected layer in a metering probe during aspiration or dispense; comparing the measured pressure with a reference value, wherein if the measured pressure and the reference value are substantially identical then the selected layer of the blood component is confirmed. In a preferred embodiment the reference value is a pre-selected pressure range.

Abstract: A method for determining a condition in a blood sample includes: providing a sample of blood; providing a metering probe having a pump for aspirating and dispensing; inserting the metering probe a selected distance into the blood sample; measuring the pressure between the sample and pump during sample aspiration or sample dispense; comparing the measured pressure with a reference value; and signaling the presence or absence of the condition. A method for confirming or detecting the presence of a selected layer of blood component in a centrifuged blood sample includes: measuring a pressure of a suspected selected layer in a metering probe during aspiration or dispense; comparing the measured pressure with a reference value, wherein if the measured pressure and the reference value are substantially identical then the selected layer of the blood component is confirmed. In a preferred embodiment the reference value is a pre-selected pressure range.

Abstract: A method for determining a condition in a blood sample includes: providing a sample of blood; providing a metering probe having a pump for aspirating and dispensing; inserting the metering probe a selected distance into the blood sample; measuring the pressure between the sample and pump during sample aspiration or sample dispense; comparing the measured pressure with a reference value; and signaling the presence or absence of the condition. A method for confirming or detecting the presence of a selected layer of blood component in a centrifuged blood sample includes: measuring a pressure of a suspected selected layer in a metering probe during aspiration or dispense; comparing the measured pressure with a reference value, wherein if the measured pressure and the reference value are substantially identical then the selected layer of the blood component is confirmed. In a preferred embodiment the reference value is a pre-selected pressure range.

Abstract: A method for determining a condition in a blood sample includes: providing a sample of blood; providing a metering probe having a pump for aspirating and dispensing; inserting the metering probe a selected distance into the blood sample; measuring the pressure between the sample and pump during sample aspiration or sample dispense; comparing the measured pressure with a reference value; and signaling the presence or absence of the condition. A method for confirming or detecting the presence of a selected layer of blood component in a centrifuged blood sample includes: measuring a pressure of a suspected selected layer in a metering probe during aspiration or dispense; comparing the measured pressure with a reference value, wherein if the measured pressure and the reference value are substantially identical then the selected layer of the blood component is confirmed. In a preferred embodiment the reference value is a pre-selected pressure range.

Abstract: A method for improving the fluid dispense rate in a metering system utilizing speed includes the steps of modifying the fluid flow rate profile during a portion thereof so as substantially increase or decrease the speed of the motor during certain portions of a metering cycle in order to improve the efficiency of the metering system. For a variable speed pump producing a sinusoidal speed profile, the pump motor speed can be increased to increase the dispense velocity during the beginning and end of the dispense phase to reduce perfusion and improve metered volume precision or a motor speed profile can be applied which is inverted relative to that of the variable speed pump to produce a constant velocity flow. Alternately or in addition to the above, the home position of the variable speed pump can be shifted to produce fluid velocity during the entirety of a dispense portion of a metering system cycle.

Abstract: A method for improving the fluid dispense rate in a metering system utilizing speed includes the steps of modifying the fluid flow rate profile during a portion thereof so as substantially increase or decrease the speed of the motor during certain portions of a metering cycle in order to improve the efficiency of the metering system. For a variable speed pump producing a sinusoidal speed profile, the pump motor speed can be increased to increase the dispense velocity during the beginning and end of the dispense phase to reduce perfusion and improve metered volume precision or a motor speed profile can be applied which is inverted a relative to that of the variable speed pump to produce a constant velocity flow. Alternately or in addition to the above, the home position of the variable speed pump can be shifted to produce fluid velocity during the entirety of a dispense portion of a metering system cycle.