Inhibition - Serum Quantitative Rule (PICQUANT_SERUM)
Version: v3.0.0 Status: Normative (text), Illustrative (diagrams only) Scope: IC inhibition evaluation for quantitative patient samples with Serum specimen type Domain: RULES-INHSERUMQUANT Precedence: Part of IC Inhibition rule family (related to PICQUANT)
Statement
The system shall evaluate Internal Control (IC) inhibition for serum quantitative samples by assessing IC CT values against thresholds and evaluating non-IC observation quantification levels.
The PICQUANT_SERUM rule implements a decision tree that passes samples with normal IC CT values (<=35) immediately. For elevated IC CT, the rule checks whether any non-IC observation has sufficient quantification (above LoD and above 10,000 copies/mL) to compensate. Samples failing both checks receive an error flag.
Quick Reference
| ID | Core Behavior | Priority | Status |
|---|---|---|---|
| REQ-RULES-INHSERUMQUANT-001 | Evaluate IC inhibition for serum quantitative samples | HIGH | Draft |
Key Integration Points: Analytics Rules Engine, Well Observations (IC CT, target quantities), Specimen Type, LoD Configuration
Rule Summary
| Property | Value |
|---|---|
| Name | PICQUANT_SERUM |
| Also Known As | Inhibition (quant) serum |
| Triggers | Serum specimen type + quantitative sample |
| Output | Pass (no error) or Error flag |
| Flow Reference | media/image158.png |
Rule Flowchart (Illustrative)
This diagram illustrates the decision logic for IC inhibition evaluation. Threshold values (35, LoD, 10,000) are configurable.
Definitions
| Term | Definition |
|---|---|
| CT | Cycle Threshold - the PCR cycle number at which fluorescence exceeds the detection threshold |
| IC | Internal Control - a control target used to validate PCR amplification occurred correctly |
| LoD | Limit of Detection - the lowest concentration that can be reliably detected (configured per mix/target) |
| PICQUANT_SERUM | Rule identifier for IC Inhibition Serum Quantification check |
| Quantification | Numerical value representing target concentration (copies/mL) from PCR analysis |
| Serum | Blood serum specimen type |
| Non-IC Observation | Any observation in the well that is not an Internal Control target |
Assumptions
- The rule is executed within the analytics rules engine framework
- Well observations include both IC and non-IC target data with CT values and quantification
- Specimen type information is available for each sample
- LoD threshold is configured and accessible at rule execution time
- The rule applies only to quantitative patient samples (not qualitative)
Requirements
IC Inhibition Evaluation (REQ-RULES-INHSERUMQUANT-001)
FR-INHSERUMQUANT-001: Evaluate IC Inhibition for Serum Quantitative Samples
The system shall execute the PICQUANT_SERUM rule to evaluate IC inhibition for serum quantitative samples based on IC CT threshold and non-IC observation quantification levels, passing samples with normal IC CT or high quantification and flagging samples with elevated IC CT and insufficient quantification.
Inputs/Outputs
| Direction | Data | Source/Target |
|---|---|---|
| Input | IC CT value | Well observation data |
| Input | Non-IC observation quantities | Well observation data |
| Input | Specimen type | Sample metadata |
| Input | LoD threshold | Kit configuration |
| Output | Pass/Error status | Rule result |
| Output | Error code (if error) | Well record |
Acceptance Criteria
Specimen Type Filtering:
- Given a non-Serum specimen type, when the PICQUANT_SERUM rule is evaluated, then the rule shall skip execution (not applicable)
- The system shall apply rule execution only to Serum specimen types
Normal IC CT Path (Pass):
- Given a serum quantitative sample with IC CT <= 35, when the PICQUANT_SERUM rule is executed, then the rule shall end without error
- Given a serum quantitative sample with IC CT exactly equal to 35, when the PICQUANT_SERUM rule is executed, then the rule shall end without error (boundary condition: <= 35)
- The system shall use an IC CT threshold value of 35, where CT values at or below this threshold shall pass immediately
Elevated IC CT with High Quantification (Pass):
- Given a serum quantitative sample with IC CT > 35 AND at least one non-IC observation with Quantity > LoD AND at least one non-IC observation with Quantity > 10,000, when the PICQUANT_SERUM rule is executed, then the rule shall end without error
- The system shall use a high quantification threshold of 10,000, where values above this threshold shall compensate for elevated IC CT
Elevated IC CT with Insufficient Quantification (Error):
- Given a serum quantitative sample with IC CT > 35 AND no non-IC observation with Quantity > LoD, when the PICQUANT_SERUM rule is executed, then the rule shall set an error
- Given a serum quantitative sample with IC CT > 35 AND at least one non-IC observation with Quantity > LoD AND no non-IC observation with Quantity > 10,000, when the PICQUANT_SERUM rule is executed, then the rule shall set an error
- Given a serum quantitative sample with IC CT > 35 and non-IC observation with Quantity exactly equal to 10,000, when the PICQUANT_SERUM rule is executed, then the rule shall set an error (boundary condition: > 10,000 not met)
Threshold Configuration:
- The system shall use the LoD (Limit of Detection) configured per mix/target as the minimum detectable quantity threshold
- The system shall evaluate quantification checks against "at least one" non-IC observation meeting the threshold
Error Handling
- No IC observation in well: skip rule evaluation
- IC CT value is null or invalid: skip rule evaluation
- No non-IC observations in well: skip rule evaluation
- LoD configuration unavailable: log warning and use default LoD
Trace: Source: 3.0.0-Inhibition - Serum Quantitative (Rows 1-3), Objective, Flow Chart (image158.png) | Jira: BT-674 (Epic: Rules - on hold) | Tests: See scenarios | Related: PICQUANT (general IC inhibition quantification rule)
Configuration Options
| Option | Default | Description | Affects |
|---|---|---|---|
ic_ct_threshold | 35 | CT value above which IC is considered potentially inhibited | REQ-RULES-INHSERUMQUANT-001 |
high_quant_threshold | 10,000 | Quantification level that compensates for elevated IC CT | REQ-RULES-INHSERUMQUANT-001 |
lod | (per mix/target) | Limit of Detection - minimum detectable quantity | REQ-RULES-INHSERUMQUANT-001 |
Open Questions
| ID | Question | Source | Owner | Date Raised |
|---|---|---|---|---|
| OQ-01 | What specific error codes should be used for IC inhibition conditions? Source does not specify - may follow ICQUANT_* pattern or use serum-specific codes | Source gap | TBD | 2026-01-22 |
| OQ-02 | Should repeat/first-run logic from PICQUANT be inherited by PICQUANT_SERUM? Source does not include this differentiation | Source gap | TBD | 2026-01-22 |
Notes
- Rule ID: PICQUANT_SERUM
- Flow diagram reference:
media/image158.png - This rule is a specimen-type-specific variant of the general PICQUANT rule
- Both rules share the same threshold values (IC CT 35, LoD check, 10,000 check)
- PICQUANT_SERUM uses the same ICQUANT_* error code pattern as PICQUANT (ICQUANT_INHN, ICQUANT_INHP, etc.)
- Repeat/first-run differentiation logic is NOT included in PICQUANT_SERUM (only present if explicitly specified in source rule)
- LoD (Limit of Detection) values are configured per assay in the config sheet
Implementation (Illustrative)
| Component | Location |
|---|---|
| PicquantSerumRule | Analyzer/Rules/PicquantSerumRule.php |
Traceability Matrix
| Requirement | Title | Verification | Implementation | Test Cases | Status |
|---|---|---|---|---|---|
| REQ-RULES-INHSERUMQUANT-001 | Evaluate IC Inhibition for Serum Quantitative Samples | Test | PicquantSerumRule | See scenarios | Draft |
Acceptance Tests
Test: REQ-RULES-INHSERUMQUANT-001
Test: Skip for non-serum specimen
Given: A well with non-Serum specimen type (e.g., Plasma)
And: IC CT value is 38
And: Target A quantification is 500
When: The PICQUANT_SERUM rule is evaluated
Then: The rule shall be skipped (not applicable to non-serum)
Test: Pass when IC CT is normal
Given: A serum quantitative sample
And: IC CT value is 30
And: Target A quantification is 500
When: The PICQUANT_SERUM rule is executed
Then: The rule shall end without error
Test: Boundary - IC CT exactly at threshold (pass)
Given: A serum quantitative sample
And: IC CT value is exactly 35
And: Target A quantification is 500
When: The PICQUANT_SERUM rule is executed
Then: The rule shall end without error
Test: Pass when IC CT elevated but high quantification
Given: A serum quantitative sample
And: IC CT value is 38
And: Target A quantification is 15,000
When: The PICQUANT_SERUM rule is executed
Then: The rule shall end without error
Test: Error when moderate quantification with elevated IC
Given: A serum quantitative sample
And: IC CT value is 37
And: Target A quantification is 5,000 (above LoD but below 10,000)
When: The PICQUANT_SERUM rule is executed
Then: The rule shall set an error
Test: Error when quantification below LoD with elevated IC
Given: A serum quantitative sample
And: IC CT value is 40
And: Target A quantification is 0 (below LoD)
When: The PICQUANT_SERUM rule is executed
Then: The rule shall set an error
Test: Boundary - Quantification exactly at 10,000 (error)
Given: A serum quantitative sample
And: IC CT value is 36
And: Target A quantification is exactly 10,000
When: The PICQUANT_SERUM rule is executed
Then: The rule shall set an error (quant NOT > 10,000)
Related Design Documents
| Design Document | Relevant Sections |
|---|---|
| SDD Algorithms | IC Inhibition Rules |
| PICQUANT Rule | General IC inhibition quantification (parent variant) |
UI Notes (Illustrative)
No UI elements are defined for this analytics rule. Rule execution is backend processing. If a UI displays rule results or allows threshold configuration, those specifications would be documented here.
Appendix: Process Artifacts
Completion Checklist
- All requirements are capability-level (describe behavior, not UI)
- Requirement variants consolidated (no requirement explosion) - N/A: single requirement
- UI details are fully demoted to Illustrative section
- Configuration options are not encoded as requirements
- Acceptance criteria describe behavior, not UI mechanics
- Every requirement has acceptance criteria and source traceability
- Error handling addressed for I/O, validation, and external system requirements
- Open questions documented with owners assigned
- Consolidations documented in Reviewer Notes with reversibility info
- Module can survive a full UI redesign unchanged
- Refinements do not introduce new capabilities
- Traceability matrix is complete
Reviewer Notes
No Consolidation Required
The source document contains a single requirement (REQ-RULES-INHSERUMQUANT-001) that comprehensively defines the PICQUANT_SERUM rule behavior. No consolidation was performed.
| Original Item | Source Reference | Disposition |
|---|---|---|
| REQ-RULES-INHSERUMQUANT-001 | 3.0.0-Inhibition - Serum Quantitative (Rows 1-3) | Preserved as REQ-RULES-INHSERUMQUANT-001 |
Enhancements Made:
| Enhancement | Rationale |
|---|---|
| Added AC for specimen type skip | Explicit behavior from SDD decision table |
| Added AC for boundary CT = 35 | Explicit edge case from SDD test scenarios |
| Added AC for boundary quant = 10,000 | Explicit edge case from SDD test scenarios |
| Added Error Handling section | Skip conditions from SDD section 6.1 |
| Added Open Questions | Unresolved gaps identified in source and SDD |
Source Files:
- Restructured:
output/pilot/rules/rule-inhibition-serum-quantitative/rule-inhibition-serum-quantitative-restructured.md - SDD:
output/pilot/rules/rule-inhibition-serum-quantitative/sdd/rule-inhibition-serum-quantitative-design.md
Reversibility: Source requirements preserved 1:1. Original acceptance criteria mapping:
- AC-01 through AC-04: Core decision paths
- AC-05: Specimen type filtering
- AC-06, AC-07: Boundary conditions
- AC-08 through AC-12: Threshold and configuration behavior