Strategies for Medical Device So2ware Development Presented By Anthony Giles of Blackwood Embedded Solu;ons And a Case Study by Francis Amoah of Creo

Transcription

1 Strategies for Medical Device So2ware Development Presented By Anthony Giles of Blackwood Embedded Solu;ons And a Case Study by Francis Amoah of Creo Medical

2 Introduc;on Standards in par;cular clause 14, SoJware development lifecycle, Risk analysis Different Companies Views of standards FDA guidance quoted Least Burdensome approach Key areas where mistakes are made SoJware Safety Class Life Cycle Model Role of Prototypes Modularising code FMEA/Risk analysis SOUP Documenta;on Case Study Creo Medical Conclusion

3 Differing Company Views of standards

4 SoJware Safety Classifica;on states The sojware safety classes shall ini;ally be assigned based on severity as follows: Class A: No injury or damage to health is possible [FDA MINOR] Class B: Non- SERIOUS INJURY is possible [FDA MODERATE] Class C: Death or SERIOUS INJURY is possible [FDA MAJOR] If the HAZARD could arise from a failure of the SOFTWARE SYSTEM to behave as specified, the probability of such failure shall be assumed to be 100 percent. FDA Guidance for the Content of Premarket Submissions for So:ware Contained in Medical Devices hhp:// Defini;on of what cons;tutes a serious injury Simple Yes/No Ques;onnaire to decide which category you fall in Common Mistake: - Avoid (We are class A ) or leave un;l to late in the project

5 SoJware Lifecycle Model Doesn t have to be Waterfall Doesn t show how prototyping fits in More modern Agile approach is to specify part of the system that is known and run through the V process mul;ple ;mes

6 Role of Prototypes Some Pros Fast Proof of Concept Helps Discover Unknown Requirements or refine requirements earlier in the Project Help get an understanding of how best to code Modules/Units for par;cular Hardware Cons Code almost never op;mum architecture Does almost never includes Risk Mi;ga;on Does almost never follows coding standards Leads to unstructured spagheo code. Not well understood as a whole or well tested Common Mistake: Not knowing when to stop prototyping and start actual design Lack of ;me/money to document test or perform Risk Mi;ga;on More buggy code Unsafe code

7 Modularising Code Breaking down complex designs in to smaller chunks Even the brightest people can hold no more than 6 individual thoughts in their heads at once Increases understanding of the workings of individual parts of the system Locks func;onality into box so you only have to understand how to use it in the system Makes it easier to understand the complex system as interfaces between individual parts Makes it easier to document Makes it easier to test individual parts Makes it easier to apply Risk Analysis/FMEA More efficient code Less documenta;on Reduced Tes;ng Common Mistake Not breaking down code into modules leads to More code to document More tes;ng More buggy code Unsafe code

8 Risk Analysis/FMEA Benefits Makes code more robust Makes sojware safe Meets requirements of Cons Adds overhead to Processor resources ;me/memory Adds a lot of addi;onal requirements to the project Common Mistakes: - Leaving to end of project Lack of paperwork Prototype lej to long and to hard understand Running out of processing resources Not having room for addi;onal safety requirements Missing essen;al risks

9 SOUP SoJware of Unknown Provenance Benefits Save Time/Money using Off the Shelf Code Fast Prototypes Cons Usually not designed to The original coders don t know your applica;on and have not implemented Risk Mi;ga;on Original requirements ojen not available to test against Common Mistakes: - Using SOUP with out understanding it In some circumstances its impossible to test Needs assessing for Risk in your product (even sojware already deemed safe) Even if full source code available, will probably need rewri;ng to fix bugs, include risk measures Supplier Documenta;on package and Test results some;mes available but at a high cost

10 Case study Creo Medical Device - State of the art electrosurgical system Outline of SoJware Applica;on (O/S- Less) Treatment control for an ac;ve surgical device Specific ;ssue effects Detec;on of abnormal accessory condi;ons User Interface Treatment ini;a;on/cessa;on Selec;on of treatment seongs (Type and Intensity) System set up (Configura;on Walk through, User Preferences Selec;on System Control Component module configura;on Component module control

11 Case study Creo Medical Timeline (Applica;on Development & Product CE Marking) Commenced Q First pass through basic func;onality completed Apr 2013 Planned comple;on of sojware project Jul 2013 Planned inclusion of Design Risk Controls (for FMEA & Risk Management) SoJware Design 'Freeze' ajer 3 MY Blackwood Embedded Solu;ons Engaged, for exper;se and resource- pinch* Genera;on of SoJware Unit specifica;ons* (1.5 MY+) Adop;on of Configura;on Management S/W* Agency review of 'SoJware Documenta;on' complete July MY coding, 2.5MY documenta;on*

12 Case study Creo Medical Outcomes SoJware not modular Many similar instances performing the same/similar func;on Each needing maintenance - specifica;on, tes;ng, repor;ng etc. Updates to func;onality inefficient Links to architecture? Addi;on of addi;onal surgical accessories uneconomic 8 person headcount involved in sojware development at end of project Poor coordina;on with milestones on the rest of the product development Stakeholder dissa;sfac;on (R&D team, management AND investors)

13 Case study Creo Medical Outcomes

14 Case study Creo Medical Revised Approach Code rewrite using best prac;ces Sequence of prescribed ac;vi;es - flowcharted processes for sojware development Structure of code - External exper;se at the paper design stage* Resource levels - More even from start Development infrastructure from start sfmeas, srmfs, Dev plans, Summary Repor;ng, CM etc Benefits Timely compliance with Regulatory Requirements (IEC cl 14, FDA, MHRA) More efficient use of resources Code wri;ng more efficient - directed func;onality, with re- use of modules Fewer mistakes in specifica;on documents & code Lower R&D cost on a comparable basis More sophis;cated func;onality (more surgical accessories, beher user experience)

15 Case study Creo Medical Ul9mate design - How clear the design can become... UI State Machine Event Queue Interrupt Driven Treatment Delivery Interrupt processing HAL I/O Timers

16 Conclusion Avoiding the standard ojen leads to more complex designs Increased Paperwork Increased Tes;ng Increased Bugs - Safety issues excessive project ;me and cost Failure to get Regulatory Approvals and to market Embracing the Standards They iden;fy a lots of risk for you and even suggest solu;ons Proven techniques to create bug free and faster to market solu;ons Reduced cost and ;mescales Almost Guaranteed Regulatory Approval As the FDA say: Embracing the standards is the Least Burdensome Approach