# Presentation: 028588

## Instrument Validation

## Pre-Installation Requirements

- Proper electrical wiring to meet manufacturer’s recommendation
- Constant line voltage
- Voltage regulator/stabilizer, if required
- Temperature controlled area to meet manufacturer’s specifications.  Large fluctuations in temperature may adversely affect results.
- Adequate de-ionized water supply
- Proper waste disposal capability
- Adequate air circulation/ flow around instrument
- Dust free environment
- Stable floor / bench top

## Out of the BoxFor the service Engineer

- Check instrument for visual damage
- Check for any loose parts or connections
- Make sure all computer boards are properly seated
- Check the wall socket to verify proper voltage outlet
- Plug instrument power cord into (voltage stabilizer) electrical supply
- Confirm the correct voltage on instrument
- Main power supply
- Photometric voltage
- Any other voltage supply that is pertinent to instrument functions

## Out of the BoxFor the service Engineer

- Permit instrument to stabilize/equilibrate
- Let all components reach proper temperature
- Set in any parameters that may be required
- Ranges
- Temps

## Begin Test Verification

- Follow manufacturers recommendation for reagent and control preparation
- Make a habit of reading package inserts
- Place reagents on instrument it required
- Place calibrators on instrument in proper order sequence

## Run calibration
If calibration is unsuccessful, then troubleshoot
1st determine of instrument or reagent problem
Verify proper prep of calibrator
If calibration is successful, then run controls
Be sure to print out the calibration results and keep the printout for future reference
If controls within stated value for analyzer and methodology, then perform linearity checks
Review linear regression curve and enzyme curve.

- If calibration is unsuccessful, then troubleshoot
- 1st determine of instrument or reagent problem
- Verify proper prep of calibrator
- If calibration is successful, then run controls
- Be sure to print out the calibration results and keep the printout for future reference
- If controls within stated value for analyzer and methodology, then perform linearity checks
- Review linear regression curve and enzyme curve.

**Begin Test Verification**

## Slide 7

## Linearity Materials and Methods

- Purpose: Verify the analytical measurement range (the lowest and highest result that can be accurately reported from the instrument.)
- Commercial materials with high values for analytes being performed
- Must not contain high levels of interfering substances such as bilirubin, etc.
- Separate materials for hematology and chemistry

## Linearity Materials & Methods

- Chemistry- bilirubin may be a separate material from material for other analytes
- Materials may be one vial with high level for several analytes and requires dilution or may be a set of samples ranging form low to high
- Make sure proper base matrix is used
- After results are obtained for each linearity sample, plot them on linear regression chart
- Check package inserts for expected values
- Review linear regression curve
- Troubleshoot if not at or near the manufacturer’s stated linearity for methodology

## Linearity Study

**Non-enzymatic (non-rate) Curve                              Enzymatic (rate) Curve**

## Precision check

- Purpose:   check reproducibility of instrument
- Precision quick method
- Run 5 replicates of one patient’s sample free of elevated bilirubin, lipemia, and hemoloysis
- Calculate % CV or SD
- Refer to the methodology in procedure manual for expected % CV or SD
- Outside of limits, then troubleshoot
- Sampling system
- Reagent delivery
- Photometer / lamp

## Carryover Study

- Place a sample with known high analyte value on the instrument
- Follow high-value sample with known low-value (as low as possible) sample for same analyte
- Check results: If low-value sample is higher than expected, there is a problem with carryover.

## Accuracy / Recovery Studies

- Run Controls
- Care must be taken that the materials used are of the same base matrix as that of the method calibrator
- If expected values are not obtained for the controls, return to the calibration procedure.

## Correlation Studies: Comparison of old methodologies vs. automated methods

**Samples  to Use:**
**Commercially prepared**
- Need spread of ranges, e.g., low, high, normal
**Patient samples**
- Must be free of interfering substances
- Need spread of ranges, e.g., from low to high
- Until all patient samples are collected:
- Freeze at -20 degrees
- Do not use home-type freezer because of freeze thaw cycles will compromise sample

## Run a minimum of 20 different patient samples
Run same samples by each method consecutively (same day)
Plot results by linear regression
X axis = automated results
Y axis = Old method results
Review linear regression curve
How do the two methods compare?
Is the slope and intercept acceptable?
If the old method will be used for back-up, it is important to know normal range for each and how well the two methods agree or disagree
How do you handle the procedures that do not correlate?

- Run same samples by each method consecutively (same day)
- Plot results by linear regression
- X axis = automated results
- Y axis = Old method results
- Review linear regression curve
- How do the two methods compare?
- Is the slope and intercept acceptable?
- If the old method will be used for back-up, it is important to know normal range for each and how well the two methods agree or disagree
- How do you handle the procedures that do not correlate?

**Correlation Studies**

## Correlation Studies

## Correlation Studies