血浆中血浆粘度检测方案(粘度计)

wowi on.com A Novel Method for the Measurement of Serum Viscosity：Evaluation of the Rheosense microVISC TM Viscometer Holly Faby， Linda C. Rogers Memorial Healthcare System， Hollywood， FL Background： Measurement of serum viscosity is used to evaluateHyperviscosity Syndrome (HVS)， which is associated with plasmacell dyscrasia， myeloma， connective tissue diseases， and otherinflammatory conditions. Rapid treatment of HVS is critical to ensureeffective reduction of risk from serious complications. Increasedviscosity， caused by the excessive intravascular paraproteins， leadsto impaired transit of blood through the microcirculatory system.The vascular stasis and resultant hypoperfusion can cause severecomplications which include cardiopulmonary symptoms such asshortness of breath， hypoxemia， acute respiratory failure，andhypotension； neurological effects such as confusion/ mental statuschanges；ocular damage including dilation of the retinal veins andretinal hemorrhages； bleeding from the mucous membranes； andrenal failure. Measurement of serum viscosity is essential for anaccurate diagnosis， but traditional methods are labor intensive andnot amenable to STAT analysis. We have evaluated a newinstrument， the Rheosense microVISCTM， for the rapid analysis of serum viscosity. Methods： The microVISCTM (Rheosense， Inc.， San Ramon， CA) isa small portable instrument which uses VROCQ (Viscometer/Rheometer-on-a-Chip) technology. The VROCQsensor obtains a viscosity reading by measuring the pressure dropas a sample flows through a flow channel. Pressure is measured atpositions of increasing distance from the inlet. The slope of thestraight line in the plot of the pressure vs. sensor position isproportional to the viscosity. We evaluated this new instrument foruse in the clinical laboratory. The performance evaluation in thisstudy included within-in run and between-run precision and linearity，using standards purchased from Rheosense， Inc. Accuracy wasdetermined by correlation of the microVISCTM (Rheosense， Inc.) to acone and plate viscometer using patient samples. We used serumsamples from patients with a normal comprehensive metabolicpanel to verify the reference range. Statistical analyses wereperformed using EP EvaluatorQ (Data Innovations). Results： The within-run precision for normal and abnormal controls was<1%. Mean/standard deviation/% CV for between-run precisionwere 1.54 cP/0.05 cP/3.25% and 4.12 cP/0.10 cP/2.43% for normaland abnormal controls respectively. The linear range was verifiedfor 0-6.38 cp. The microVISC correlated well with the cone andplate method： y=0.836x+0.064 (r=0.979). The small negativebias was reflected in a slightly lower reference range of 1.10-1.60cP for serum samples. Conclusions： We validated the microVISC instrument for the rapid，accurate， and reproducible measurement of serum viscosity in aclinical laboratory setting. The instrument is small， portable， andeasy to use and maintain. Rheosense microVISC viscometer The definition of viscosity is the measurement of the resistance of a Method and Procedure liquid or fluid to flow. It is a characteristic property of a fluid and aconstant for a given liquid at a given temperature (for Newtonianfluids). The fluid must be in motion for the property of viscosity to beobserved.. Plasma and serum are Newtonian fluids. Their viscositiesare the same regardless of the speed at which they are flowing.Methods for the measurement of plasma， serum， and whole bloodviscosity all require the sample to flow. To measure the viscosity of asample， modern viscometers measure the rate of fluid flow at aspecified force or pressure. The conventional unit of viscositymeasurement in the metric system is the poise. Viscosity values forbiologic fluids are in centipoise (cP)， which is equal to 1/100 of apoise.The microVisc requires only 100 uL of sample and results areavailable in 60 seconds. It is a small portable instrument weighingonly 1.6 Ibs. The microVISC TC， a precise temperature controller，can keep the temperature constant to minimize variability. All samples were analyzed at 37°C. Calibration： The microVISC is calibrated from the factory with asensor cartridge or chip which is re-calibrated annually by company，Rheosense. Several sensor chips are available which measuredifferent ranges of viscosity. The chip used for serum measurements is designed to test viscosities from 0.0-10.0 cP. Accuracy： 40 patient serum samples were assayed using theRheosense microVISC TM viscometer. Aliquots of the 40 serumsamples were shipped to a reference laboratory for analysis using acone and plate viscometer. Deming regression analysis was usedfor statistical correlation. Precision： Within-run precision was determined with multiplemeasurements of a"normal"control (MGVS60) and a"High/Abnormal" control (MGVS20) purchased from Rheosense，Inc，). Between-run precision was determined by analyzing thecontrols (MGVS60 and MGVS20)， daily for 25 days. Linearity： Linearity was determined by analyzing 3 samples ofknown concentration (water， and 2 standards) in quadruplicate.Reference range Verification was performed using 30 patientsamples with normal comprehensive metabolic panels.Statistical Analyses were cslculated using EP Evaluator. Rheosense microVISC viscometer within temperature controller Figure 1： Method Correlation for microVISC versuscone & plate Table 1： Precision Within Run PrecisionBetween Run Precision Within Run Precision Between Run Precision Mean (cP) SD (cP) %CV Mean (cP) SD (cP) %CV Normal (MGVS60) 1.50 0.050 0.64 1.54 0.05 3.25 High/Abnormal (MGVS20) 4.00 0.021 0.57 4.12 0.10 2.43 Figure 2： Linearity Conclusion 1. The microVISC viscometer is an instrument that has beenvalidated successfully for application with clinical specimens. 2. The microVISC viscometer provides accurate and precise resultsfor clinical serum samples. 3. The microVISC viscometer is simple to use and provides rapidresults for serum viscosity in a clinical setting 检测样品完全封闭，避免外界介质干扰。剪切速率：1.7-5800 1/S小样本容量：100ul检测时间：＜1min粘度范围：0.2 ~ 20000 mPa·s精度：2%（读数）重现性：0.5%（全量程）重量：＜1kg温控范围：18-50℃ (内置温控传感器）温控精度：0.15℃