METHODS AND APPARATUS FOR MEASURING ASPIRATION PRESSURE AT LOW ASPIRATION VOLUMES
First Claim
1. A method of detecting aspiration pressure during aspiration of a liquid, comprising:
- attempting to aspirate a volume of a liquid into a probe at an aspiration frequency;
measuring an aspiration pressure associated with the attempted aspiration of the liquid and providing a measured pressure signal; and
filtering the measured pressure signal with a filter having a passband containing the aspiration frequency and attenuating frequencies of a disturbance causing noise in the measured pressure signal to obtain a filtered pressure signal.
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Accused Products
Abstract
A method adapted to allow aspiration verification of a liquid such as a biological liquid or liquid reagent at low aspiration volumes (e.g., less than 25 μL). The method includes attempting to aspirate a volume of a liquid into a probe at an aspiration frequency, measuring an aspiration pressure associated with the attempted aspiration of the liquid and providing a measured pressure signal, and filtering the measured pressure signal with a filter. The filter has a passband frequency containing the aspiration frequency and excluding the frequencies of a disturbance causing noise in the measured pressure signal. Apparatus for carrying out the method are provided, as are other aspects.
16 Citations
32 Claims
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1. A method of detecting aspiration pressure during aspiration of a liquid, comprising:
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attempting to aspirate a volume of a liquid into a probe at an aspiration frequency; measuring an aspiration pressure associated with the attempted aspiration of the liquid and providing a measured pressure signal; and filtering the measured pressure signal with a filter having a passband containing the aspiration frequency and attenuating frequencies of a disturbance causing noise in the measured pressure signal to obtain a filtered pressure signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A method of detecting aspiration pressure during aspiration of a liquid, comprising:
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attempting to aspirate a volume of a biological liquid or a liquid reagent into a probe wherein the attempted aspiration is carried out at an aspiration frequency over an aspiration cycle and the total aspirated volume is less than 25 μ
L;measuring with a sensor an aspiration pressure associated with the attempted aspiration and providing a measured pressure signal over at least a portion of the aspiration cycle; filtering the measured pressure signal with a filter having a passband that includes the aspiration frequency and excludes a dominant resonant frequency of a disturbance causing noise in the measured pressure signal to provide a filtered pressure signal; and verifying at an evaluation point of the filtered pressure signal whether the attempted aspiration resulted in a desired volume of biological liquid or a liquid reagent being aspirated.
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30. An aspiration apparatus, comprising:
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a probe adapted to aspirate a liquid; a pump adapted to cause the liquid to aspirate into the probe at an aspiration frequency; a pressure sensor adapted to measure an aspiration pressure during the aspiration and provide a measured pressure signal; and a filter adapted to filter the measured pressure signal, the filter having a passband containing the aspiration frequency and excluding any frequency of a disturbance causing noise in the measured pressure signal. - View Dependent Claims (31, 32)
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Specification