Dynamic Reference Ranges for Medical Lab Quality Control

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Solution Overview

Problem

Existing laboratory testing systems fail to account for newly observed variations in analyte values, leading to flawed quality control procedures and inefficiencies, as they rely on static reference ranges that do not reflect temporal or demographic changes in patient populations.

Innovation Solution

A computer-based quality control system that calculates a grade for test batches by factoring in time-periodic and demographic variations, using reference ranges adjusted for parameters like age, sex, and location, to determine whether tests need retesting or can be released, thereby avoiding false positives.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If static reference ranges are used for quality control, then the quality control procedure is simple and efficient, but the reliability of quality control deteriorates because newly observed variations in analyte values are not reflected

Engineering Contradiction:
Improvequality control reliabilityVSAvoidquality control system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent transforms static reference ranges into dynamic reference ranges that automatically adjust based on newly observed analyte variations. The system continuously updates reference ranges using statistical methods (e.g., moving averages, control charts) that incorporate recent test results, allowing the quality control system to adapt to temporal variations in analyte values while maintaining automated operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system implements feedback loops where test results are continuously monitored and fed back into the reference range calculation process. When variations in analyte values are detected, the system automatically adjusts reference ranges and notifies relevant personnel, creating a closed-loop quality control system that responds to actual performance data.

Inventive Principle:
Principle #23Feedback

2Productivity

If static reference ranges are used, then the system is easy to operate, but false positives increase causing unnecessary retesting

Engineering Contradiction:
Improvetesting throughputVSAvoidquality control accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent changes the parameters of reference ranges from fixed values to dynamically adjustable values based on statistical analysis of test results. The system monitors parameters such as mean, standard deviation, and coefficient of variation, and automatically adjusts reference ranges when these parameters indicate genuine shifts in analyte values, thereby reducing false positives while maintaining operational efficiency.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If dynamic reference ranges incorporating temporal and demographic variations are implemented, then the accuracy of quality control improves, but the complexity of the system increases

Engineering Contradiction:
Improvequality control accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the population into demographic subgroups (e.g., age groups, sex, ethnicity) and establishes separate dynamic reference ranges for each segment. This allows the system to account for demographic variations in analyte values without requiring an overly complex monolithic model, as each segment can be analyzed and updated independently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system adds temporal and demographic dimensions to the reference range model, transforming it from a single static value to a multi-dimensional framework that varies by time, population segment, and analyte type. This dimensional expansion enables more accurate quality control while using standardized statistical methods that can be implemented through automated software.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Reliability

If traditional quality control methods are used, then the process is fast and simple, but unnecessary retesting occurs reducing productivity

Engineering Contradiction:
Improvetest result reliabilityVSAvoidretesting time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary statistical analysis and dynamic reference range updates before final quality control decisions are made. By proactively adjusting reference ranges based on observed variations and notifying personnel in advance, the system prevents false positive flags that would otherwise trigger unnecessary retesting, thereby saving time while maintaining reliability.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS10325067B1Statistical quality control of medical laboratory results
Publication Date: 2019.06.18 QUEST DIAGNOSTICS INVESTMENTS INC
  • US10325067B1 patent drawing
  • US10325067B1 patent drawing
  • US10325067B1 patent drawing

AI summary

Laboratory testing plays a significant and growing role in the delivery of medical services. Fresh analysis of past test results has led to discovery of previously unknown correlations between statistical properties of analyte values and parameters such as age, sex, and region. Observed values in patient populations have also newly been discovered to show both secular and regular periodic variations over time. Embodiments of the invention may use information about these correlations to improve quality control and other statistical analysis of patient samples by applying adjusted reference ranges to quality control methodologies, and providing a quality control grade for patient samples based on the adjusted reference ranges.