Development of an equipment and calibration

verification framework

Martin Green, Richard Clements

Background

• Reliant on users and process to assure quality• Taking a reliable overview not possible

Requirements

• Record QA test results• Easily accessible by multiple concurrent

users• Overview of failing QA• Show trends in parameters• Allow tests to be performed efficiently• Temporally aware

Development Methodology V-model

Requirements

Design

Coding Unit Testing

Integration Testing

Acceptance Testing

System Requirements

System Verifications

Independent Acceptance Plan

System Testing Plan

Integration Testing Plan

Test Driven Development

Development Methodology Incremental

Picture: Incremental Model/RahulT/Creative Commons

System Requirements

Can we hard code an application to perform the tests we require?• There are hundreds of different tests• The tests we have are regularly changing• Tests are for multiple sub disciplines

A framework was required to allow domain experts to configure the QA program

Accessibility requirements fulfilled by a web application

System Requirements - Stacks

Server Side Client Side

System Requirements - Django

ControllerURL dispatcher

ViewProcess requests

ModelObject Relational Mapper

RequestHTTP Get/Post Response

HTML, JSON, JS, CSS

Template

Design - Data Model

Calibration Type

Calibration Verification Type

Calibration Verification Requirement

Form Type

Equipment Instance

Equipment ClassificationEquipment Type

Calibration Instance

Calibration Verification Instance

Form Instance

Configuration Routine

Design - Calibrations

Calibration Type Calibration Instance

Unique ID10XEOUTPUT5

VariablesOutput: 1.0 cGy/MU

EquipmentLinac: M10-5 Rowan

Conditions100cm SSD, 10cm x 10cm field

at Dmax depth

ReferencesReference to controlled document

AuthorisationFrom 2010-12-11 (JBloggs)

Unique ID Prefix10XEOUTPUT

Named Variables and UnitsOutput - cGy/MU

Named EquipmentLinac – 10MV Linac

Examples shown in grey

10MV Linac Output

Design - Calibration Verifications

Input ValuesTemperature - °C, Pressure – mbar, Readings - nC

Input Calibrations (calibrations contain variables)Energy, Felec, Fion, NDw

Calculations FTP = (Temperature + 273) * 1013.25 / (293 * Pressure)Rmean (nC) = mean(R1, R2, R3)Output (cGy/MU) = Rmean * FTP * NDw.Value * Felec.Value * Fion.Value / Energy.PDD5

Pass Functionabs(calibration.Output-Output) / calibration.Output < 0.03

Validations15 < Temperature < 30 - Temperature outside expected range0.02 > abs(calibration.Output-Output)/calibration.Output - Please check your setup

Examples shown in grey

Calibration Verification Type

Water Farmer Output Check

Design - Forms

Form Type

Water Farmer Output Check

Design - Forms

Form Instance

Water Farmer Output Check

Design - Forms

Form Instance

Water Farmer Output Check

Design - GraphsLinac Output Checks

Design - Dashboard - Overview

Design - Dashboard – Drilling Down

Situation so far

• Implemented checks:Linac, brachytherapy and orthovoltage output checks

Radiographer daily checks

Automated server disk space checks

• Saves time during morning machine checks• In use for 4 years• 30,000 forms entered• 200,000 checks recorded

Further Work

• Allow verifications to depend upon other verifications:Eg. Definitive calibrations rely upon:

Beam profile checks and

Farmer chamber consistency checks

• Train more Domain Experts

• Implement remaining QA checks

• Automate System verification

Further Work – Graphing

Seth M. Powsner and Edward R. Tufte, "Graphical Summary of Patient Status", The Lancet 344 (August 6, 1994), 386-389