unit 1 Automation Flashcards
name and description of first automated analyzer
“autoanalyzer” a contionous flow, single channeled sequential batch analyzer ( a single test was run on about 40 samples/ hour) introduced in 1957
second generation of automated analyzers name and description
“simultaneous multiple analyzer(SMA)
multiple channels produced 6-12 tests simultaneously at a rate of 360-72- tests/hour
problems with continuous flow analyzers
carryover and costly reagent waste
first commercial centrifugal analyzer was developed by
Dr. Norman Anderson at Oak Ridge National Laboratory, it was a spin-off technology from NASA space research, introduced in 1970 and was an alternative to continuous flow technology.
Automatic clinical Analyzer introduced by, and was the first ( 2 things) plus unique features
DuPont (1970), was the first discrete analyzer ( non continuous flow analyzer), and was the first to have random access capabilities. unique features: plastic test packs, positive patient ID, infrequent calibration.
Thin film analysis technology, year introduced
1976
Kodak Ektachem Analyzer; produced in what year, first instrument to use..,
produced in 1978, first instrument ties micro sample volumes and reagents slides for dry chemistry analysis( now VITROS)
first instrument to incorporate computer technology extensively into its design and use.
primarily discrete analyzers since what year, describe differences ( tests, menu, computer)
since 1980,
ion-selective electrodes, fiberoptics, polychromatic analysis
sophisticated computer hardware and software for data handling
larger test menus
recent advances (3)
point-of-care bench top analyzers
immunochemistry analyzers
modular analyzers
point-of-care analyzers
small, portable, easy to operate.
used primarily in physicians offices, laboratories and surgical and critical care units.
immunochemistry analyzers
using antigens and antibodies to test drug assays, specific proteins, tutor markers, and hormones.
instruments using florescence polarization immunoassays, nephelometry and immunoassay with chemiluminescent detection.
modular analyzers
combination of chemistry and immunoassay ( larger places combine these two)
phases of the testing process
pre-analytical(sample processing), analytical( sample analysis) and post-analytical( data management)
pre-analytical
test ordering, patient prep, collection and transport, processing ( aliquoting, centrifuging etc)
analytical
chemical analysis, calibration and controls, analyzer maintenance
post-analytical
data management, validation results, generation of patient reports, electronic posting results to patient record
Automation uses
robotics and front-end sample processes (pre-analutical)
barcodes applied at collection and read by analyzer for ID
assessments of results( automatic verification, flagging abnormal or critical results, auto dilution if a sample is greater than the linearity, delta checks)
automation in chemistry, hematology, microbiology, immunology, and transfusion science
chemistry: batch and random access analyzers
hem: CBCs, differentials, cell classification
micro: bacterial ID
immunology: immunoassays
trans: automated screening and X-matches
goals/ advantages of automation
cost reduction( increased in number of tests performed by one MLT; decreased cost per test. Decreased volume of samples and reagents needs)
expansion of test menus( more options)
reduced turn around time(faster diagnosis faster treatment)
reduced variation (better comparison of results)
reduced errors( greater standardization between MLTs)
improved Lab safety (less handling of samples and reagents)
continuous flow analyzers( older/obsolete)
liquids are pumped through a system of continuous tubing, introduced in sequential order( seperated by air bubbles)
batch analysis only
centrifugal analyzers
force of centrifugation mixes reagents and samples
capable of batch analysis only
need MLT to load and transfer rotor
Discrete analysis
separation of each sample and reagent in a separate container
most popular type
can run multiple tests at one time or mulitple samples one test at a time
only one with Random access ability
steps in automation
specimen prep and ID specimen measurement and delivery reagent delivery chemical reaction measurement signal processing and data handling
specimen prep and ID
specimen prep is still manual in most labs, prep can be automated with robotics and front-end automation
primary tube sampling can be preformed on serum and plasma separator tubes after centrifugation
sample ID/location of specimens ( IMPORTANT)
bar code labels( ID samples and position on analyzer)
- with a LIS system it allows 2 way interface between instrument and lab software; orders downloaded from LIS and results are uploaded to patient file for Dr to see)
faster TAT
specimen measurement and delivery
concern
circular carousels or rectangular rails hold disposable cups or primary sample tubes ( holds samples, controls and standards)
cups are marked to fill volume(0.5-2mL)
an aliquot of each sample is measured through aspiration of sample into a probe, some analyzers have cap-piercing probes.
probe and tubing is cleaned after each dispensing to minimize carryover, unless disposable probes or tips are used.
concern- carryover
carryover and how to minimize
when a previous sample contaminates the current sample
minimize: probe washes between samples, back flush of probe, use of disposable tips
reagent systems
dry reagent: lyophilized powder-requires reconstitution
tablets
multilayer dry chemical slides(ex.VITROS)-contains entire reagent system, single use
liquid reagent( bulk or unit dose) ex. abbott architect AU480
Proportioning definition
Adding patient sample to reagent
Reagent delivery dispensing methods
Syringes ( pipette samples and reagents into cuvettes)
Peristaltic or piston driven pumps force liquid through tubing
Electric valves flow of reagents is controlled by a computer
Chemical reaction phase ( 3)
Mixing : coiled timing, diffusion ( slide technology), centrifugal force, motion, spin bars, agitation, forceful dispensing, start/ stop action, stirring paddles
Incubation: heating bath( water or air) to maintain a temperature ( usually 37). Delay station permits curettes to incubate in a chamber for a set time
Reaction time: endpoint or kinetic ( continuous monitoring or rate )
Which analyzer use stirring paddles
Only wet chemistry analyzerss
Measurement phase
Principles
- ultraviolet , fluorescent, and flame photometry
- ion-selective electrodes (ISEs) * for electrolytes
- gamma counters
- luminometers
- visible and ultraviolet light spectrophotometer ( most common) *** for general chemistry
- fluorescence polarization, chemiluminescence, bioluminescence…. For immunoassays
Dry chemistry/ slide chemistry analyzers ( exVITROS)
Use reflectance spectrophotometry *
Reflected ( not absorbed ) light is measured
More Color= higher concentration of analyte = lower reflectance
Accurate calibration importance
Is essential to obtaining accurate information, multiple instruments that measure the same constituent in a lab should be calibrated so that results are compatible
Once calibrated, automated instruments provide long term stability of the standard curve amc only require monitoring
Some instruments are self- calibrating
Signal processing
Analog signals ( ex.voltage or current ) are converted to a digital signal that can be processed by a computer
Microprocessors are and are responsible for
Computers that hook up to analyzers, they are responsible for
- Data management ( abs readings, calculations, matching patient with results)
- Process control ( timing pipetting, incubation, readings)
- Quality control/ maintenances ( monitors QC; flags QC results that fail)
A monitor / display allows MLT to review results ( validate / verify )
Results can be hard colony or interfaced (LIS)
Auto verification
Can be preformed by LIS
The computer automatically verifies and releases normal results or results within set parameters
I.e results within reference range, no flags, no delta checks warnings no QC issues
Delta checks
Comparison of current results with previous results
Back- end
Removing from analyzer & storing, retrieving if re-testing is required or disposal of specimens after appropriate amount of time.
Throughput
The max# of tests that can be performed at the steady rate
Workload
The # of tests results generated during a given period of time
Workflow
The way in which tests are processed ( STATS ASAPs, batches )
Test mix
The variety of tests that can be run
Sensitivity
The lowest value that can be detected by a method without giving a false positive
Specificity
The ability of a method to only measure the analyte in question
TAT
“ turn around time” is the time it takes for to analyze specimen and report results
Batch analyzer
When multiple patients samples are run during one test run
Random access ability
Allows the order of tests run to be changed during a run ( good for STATS)
Primary tube sampling
Test performed on serum or plasma spectator tube instead of an addition container being used
Download
Orders are downloaded from LIS
Upload
Results are uploaded to patient file
