Feature Article

Developing Medical Device Software to IEC 62304


Posted in Medical Software by Brian Buntz on June 1, 2010

Medical software design standard IEC 62304 has just come into force. This article describes how it will impact the software development process for medical device manufacturers.


Standards for medical device design
Until recently, safety regulations for medical device software, at least formally, were not exceptionally rigorous across the board. In addition, software was not formally classified as a medical product by the Medical Devices Directive. This has now changed. A new regime is in force governing all medical device software development for all classes of device.
 
Previous software safety standards were best suited to medical devices with low levels of risk, as opposed to products where software failure could be extremely serious and result in death. As more electronic products have become dependent on embedded software, the focus has shifted to the reliability of software systems within the devices and the associated risks at all levels of usage. As a result, the new EN/IEC 62304 standard has emerged as a global benchmark for management of the software development lifecycle (Figure 1).
 
Risk analysis for hardware and software design
Medical product designers have used risk management techniques to help reduce the risks associated with device hardware. BS/EN/ISO 14971 has traditionally been adopted as the base standard for risk management for medical devices. The 2007 version of this standard is considerably extended from its previous version, and the techniques described are now intended to be applied to both software and hardware systems.
 
The approach that should be taken is to consider the risks posed by the medical device as a whole, before the software/hardware split has been decided. Hardware risk analysis can then run alongside software risk analysis to define the required safety systems for the device.
 
A harmonised standard
Figure 1: How IEC 62304 fits into the compliance process and its relationship with other standards.
IEC 62304 is a harmonised standard for software design in medical products adopted by the European Union and the United States. Because the standard is “harmonised,” medical device manufacturers adopting it will satisfy the essential requirements contained in Medical Devices Directive 93/42/EEC (MDD) with amendment M5 (2007/47/EC) as related to software development. This is the least onerous route to ensuring compliance with the MDD. US FDA will also accept ANSI/AAMI/IEC 62304:2006 as evidence that medical device software has been designed to an acceptable standard. This standard is identical to the EN/ISO variant in all essential details.
 
Designing to IEC 62304 ensures that quality software is produced by means of a defined and controlled process of software development. This process must contain a set of requirements based on the safety class of the software that is being developed.
 
Software safety classification
Initially the IEC 62304 standard expects the manufacturer to assign a safety class to the software system as a whole. This class-ification is based on the potential to create a hazard that could result in an injury to the user, the patient or other people.
 
The software is classified into three simple classes, as follows:
  • Class A: No injury or damage to health is possible
  • Class B: Nonserious injury is possible
  • Class C: Death or serious injury is possible
Defining “serious injury,” “nonserious injury,” “injury” and “damage to health” is important to apply this classification effectively. It may at first appear to be obvious what constitutes an injury; however, this can be a far more complex question when the context of the device is taken into account. Unfortunately the standard only defines “serious injury,” and this is as follows:
 
Serious Injury
Injury or illness that directly or indirectly
a) is life threatening,
b) results in permanent impairment of a body function or permanent damage to a body structure, or
c) necessitates medical or surgical intervention to prevent permanent impairment of a body function or permanent damage to a body structure.
 
Note: Permanent impairment means an irreversible impairment or damage to a body structure or function excluding trivial impairment or damage.
 
Figure 2: A safety-critical software system can be split into items, each one running on different processors and each with a different safety classification. 
 
It is relatively simple to apply a negative to the above to derive a nonserious injury definition. However, the definition of injury for use with the Class A software safety classification may be debatable. This is complex because of the lack of definition of injury or damage to health. For example, there may be a grey area involving the normal side effects of treatment of a condition as opposed to the device itself causing injury.
 
Procedures for carrying out this initial analysis and defining the class to be applied have been developed. In some cases, the notified body being used can affect this decision. Some will recommend that Class B is the minimum standard to be applied for any medical product, as the Class A safety classification does not insist on a sufficiently rigorous software development process.
 
There are major differences in the development process in terms of cost and time between a Class A and Class B code. It is therefore essential that medical device developers get this right at the outset. The safety classification also has a great impact on the documentation and process that is required.
 
Software items and units
Once the initial safety classification has been carried out for the system, it is possible to break the system down into software items and software units. These are defined as follows:
  • Software Item: “Any identifiable part of a computer program” [ISO/IEC 90003:2004, definition 3.14, modified]
  • Software Unit: “Software item that is not subdivided into other items” [ISO/IEC 90003:2004, definition 3.28, modified]
In practice, the software items can be any subsection of a system or its constituent parts. An architectural diagram is required to show the software items and software units. It is possible to then downgrade the safety classification of parts of the software system provided that these can be segregated. The note on section 5.3.5 of the standard gives an example of this segregation:
 
“An example of segregation is to have software items execute on different processors. The effectiveness of the segregation can be ensured by having no shared resources between the processors.”
 
In practice, this means that a safety-critical software system can be split into items, each one running on different processors and each with a different safety classification (Figure 2). Again, it is important to get this split correct at the outset to ensure that the system is safe and high quality, but also produced within the appropriate cost and time guidelines. Systems are available to analyse medical product software architecture and to define these items. Such processes can greatly reduce timescales and costs for the development of medical devices.
 
Table I: Summary of safety classification effects on the code development documentation and process.
Software Documentation Class A Class B Class C
Software development plan Must contain contents to sections 5.1 IEC 62304:2006. The plan's content list increases as the class increases, but a plan is required for all classes.
Software requirements specification Software requirements specification conforming to 5.2 IEC 62304:2006. The content list for the software requirements specification increases as the class increases, but a document is required for all classes.
Software architecture Not required. Software architecture to 5.3 IEC 62304:2006. Refined to software unit level for Class C.
Software detailed design Not required.   Document detailed design for software
units. (5.4).
Software unit implementation All units are implemented, documented and source controlled (5.5.1).  
Software unit verification Not required. Define process, tests and acceptance
criteria (5.5.2, 5.5.3).
Carry out verification (5.5.5)
Define additional tests and acceptance
criteria (5.5.2, 5.5.3, 5.5.4).
Carry out verification (5.5.5).
Software integration and integration
testing
Not required. Integration testing to 5.6 IEC 62304:2006.
Software system testing Not required. System testing to 5.7 IEC 62304:2006.
Software release Document the version of the software
product that is being released (5.8.4).
List of remaining software anomalies, annotated with an explanation of the
impact on safety or effectiveness, including operator usage and human factors.
 
Impact of safety classification
The safety classification has a tremendous impact on the code development process. It is therefore in the interests of medical device manufacturers to get this right the first time to avoid expensive, time-consuming rework late in a project.
A brief summary of the effects of safety classification on the documentation and process is shown in table I. In practice any company developing medical device software will carry out verification, integration and system testing on all software classes. However, the difference is that formal detailed documentation does not need to be generated for Class A code. Cross-referencing and verification of requirements also does not need to be formally proven. This can save a great deal of time and money in software development.
 
SOUP
Software of unknown provenance, or SOUP, is any code (tools or source code) that does not have formal documentation or was developed by a third party and has no evidence as to the controls on the development process. This code by definition is deemed to be capable of producing faults. It is important to carry out a software risk analysis on any SOUP code being proposed for the software under development and produce a rationale as to why this code should be used.
 
The use of SOUP is affected by the code safety classification. If the code is deemed to be Class A, then SOUP code can be used without further justification. As the class increases, the risks increase and the rationale becomes harder to justify. In practice this means that only simple function, well known and diversely applied SOUP code can be used for Class C applications.
 
A technology solutions provider specialising in electronics design and production services has developed processes to identify and justify the use of SOUP in medical device software. Its own experience with this has proved that such processes can drastically reduce development time-scales and costs. This is a route that medical device developers should incorporate into their design procedures.
 
Conclusion
IEC 62304 is a well considered, logical standard for developing safety critical and high reliability software for medical devices. Now that this standard has been adopted it would be very difficult for a medical device software developer to justify any equivalent approach that meets the requirements of the MDD, without effectively complying with this standard. This is good news for the safety of patients, but also for the manufacturers themselves, as the standard establishes a more level playing field. There is no longer any opportunity for uncontrolled rudimentary software development processes, and this raises quality across the board.
 
In addition, as IEC 62304 is a harmonised standard that has been adopted internationally, it tends to equalise quality expectations between Europe and the United States.
 
For medical device manufacturers, it is important that they select software designers who have well-established risk management systems, as they will already have the foundations in place to meet IEC 62304. Additionally, my professional experience has proved how valuable processes can be to analyse medical product software architecture and usage. Such processes can greatly reduce timescales and costs for the development of medical devices. 
 
Ken Hall
is Technical Director at Triteq Ltd,
3 The Courtyard, Stype, Hungerford,
Berkshire RG17 0RE, UK
tel. +44 1488 684 554
e-mail: ken.hall@triteq.com
www.triteq.com
 
 

 

Related stories

Simplifying IEC 62304 Compliance for Developers
 

Decoding MISRA C:2012 for Medtech Applications



Find more content on:
Your rating: None Average: 4.5 (2 votes)


Login or register to post comments

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

Great survey, I'm sure you're

Great survey, I'm sure you're getting a great response.
clear facebook activity log android phone

If you're in a not good

If you're in a not good position and have got no cash to move out from that point, you would have to receive the..
Seo Service

These are some great tools

These are some great tools that i definitely use for SEO work. This is a great list to use in the future..
gfas system review

Well, the information you

Well, the information you have posted in this post has many new things to understand. latest software

Well, it is an amazing and

Well, it is an amazing and interesting information which have never been shared before. software crack

I can set up my new idea from

I can set up my new idea from this post. It gives in depth information. Thanks for this valuable information for all,..
Victorino Noval Philanthropist

Pretty good post. I just

Pretty good post. I just stumbled upon your blog and wanted to say that I have really enjoyed reading your blog posts. Any way I’ll be subscribing to your feed and I hope you post again soon.
best mattress for hip pain

These are some great tools

These are some great tools that i definitely use for SEO work. This is a great list to use in the future..
http://www.freeonlinedatingheadquarters.com/how-to-get-a-girl-everyone-wants

https://www.flickr.com/people/buyfacebooklike/

Hi there, I found your blog via Google while searching for such kinda informative post and your post looks very interesting for me.
Buy Facebook Likes Cheap

emdt

Wonderful tips guys! They are extremely actionable and practical. http://discounthoarder.com/ Pleases stop by and check out my blog

Fotograf Reinhard Simon und

Fotograf Reinhard Simon und Waltraud Pioch begrüßen Sie herzlich in ihrem Fotostudio “das portrait” in Frankfurt. Fotoatelier für anspruchsvolle Fotografie. Die erste Adresse in Frankfurt für Bewerbungsfotos, Businessfotos und Portraitfotos. Frankfurt

very interesting post.this is

very interesting post.this is my first time visit here.i found so mmany interesting stuff in your blog especially its discussion..thanks for the post!
https://www.rebelmouse.com/bobbyriomagneticmessaging

unlimited iron boom beach

get unlimited woods and unlimited iron boom beach by using the online resource generator

wallens

This is my first time i visit here. I found so many interesting stuff in your blog especially its discussion. From the tons of comments on your articles, I guess I am not the only one having all the enjoyment here! keep up the good work
Technology news

dfdfdf

Hi there would you mind letting me know which
hosting company you’re working with? I’ve loaded your blog in
3 different web browsers
and I must say this blog loads a lot quicker then most.
Can you recommend a good hosting provider at a reasonable price?

Kudos, I appreciate it!
Simcity buildit hack

Der Schwerpunkt unseres

Der Schwerpunkt unseres Angebots liegt in der Konzeption, Gestaltung und Entwicklung von Websites sowie im Online Marketing. SEO-Optimierung, Social Media Marketing (SMM) oder Responsive Webdesign sind dabei keine Fremdwörter für uns, sondern Teil unserer täglichen Arbeit.Joomla

Apps for iPhones, iPads

There are numerous free medical apps for iPhones, iPads, and android smartphones which fall into many categories of medical applications. best android apps

Packers and Movers India

Thanks for post this helpful post - Please visit for More information about -
Packers and Movers Pune
Packers and Movers Hyderabad
Packers and Movers Mumbai

Packers and Movers India

In situation you will need they’ll likely could also offer you car or truck company & journey support, puppy shifting alternatives, position shifting support and warehousing & storage area place position place support.
Packers and Movers Mumbai
Packers and Movers Chennai
Packers and Movers Delhi
Packers and Movers Bangalore

There were also tributes to

There were also tributes to those who had lost their cancer battle.Around the room shoulders trembled, eyes welled up. Riding alone in a cold rain is not suffering, I think. It could be far, far worse.. dong ho deo tay dep

https://www.youtube.com/watch?v=juX4jmjdu4s

Pretty good post. I just stumbled upon your blog and wanted to say that I have really enjoyed reading your blog posts. Any way I’ll be subscribing to your feed and I hope you post again soon.
Buy Facebook Likes

I m saving your blog in my

I m saving your blog in my personal folder to visit again You made legal points within this article that I sense need further examination. I agree with most all of this info. amazing work. dong ho deo tay

Berita terkini liputan6

Kumpulan berita terbaru hari ini persib paling baru Liputan6.com

Berita terkini liputan6

Kumpulan berita terbaru hari ini sepak bola paling baru Liputan6.com

Berita terkini liputan6

Kumpulan berita terbaru hari ini Berita terbaru paling baru Liputan6.com
Kumpulan berita terbaru hari ini detik paling baru Liputan6.com
Kumpulan berita terbaru hari ini jadwal bola paling baru Liputan6.com

That appears to be excellent

That appears to be excellent however i am still not too sure that I like it. At any rate will look far more into it and decide personally!
www.immo-consult.be

http://www.bestmattressonline.com/best-mattress-options-for-plat

I must say, I thought this was a pretty interesting read when it comes to this topic. Liked the material. . . . .
platform bed mattress

This has now changed. A new

This has now changed. A new regime is in force governing all medical device software development for all classes of device.obat pelangsing

I wanted to see hope in

I wanted to see hope in future you will continue for sharing such a excellent post. psd to wordpress

http://www.memoryfoammattress-guide.org/guide-to-top-memory-foam

I would like to thank you for the efforts you have made in writing this article. I am hoping the same best work from you in the future as well. In fact your creative writing abilities has inspired me to start my own BlogEngine blog now. Really the blogging is spreading its wings rapidly. Your write up is a fine example of it.
best memory foam mattress

how to talk dirty to your man

how to talk dirty to your man and turn him on Felicity Keith Language Of Desire Review – Do These Dirty Words Really Make Him Yours? Holy moley! It seems like I can’t go anywhere online the last few days without hearing something about Felicity Keith’s new dirty talk guide called the Language of Desire (or just LOD for short). All the relationship blogs, forums, and Facebook pages I frequent on a regular basis are going nuts about it! There are Language of Desire reviews springing up everywhere. Please visit site: http://copyfight.org/felicity-keith-language-of-desire-review-do-these-d... ...

https://rebelmouse.com/dramam

https://rebelmouse.com/dramamethodreview The Drama Method: Aaron Fox Reveals Weird And Outrageous Ways To Use Drama To Trigger Unconditional Love, Affection, And Desire In Any Man. This site includes a Drama Method review and buyers guide that provides an insider's look at the program and answers frequently asked questions about Aaron Fox's unique and highly popular system for using drama in a specialized way to actually drive men crazy for you instead of driving them away. Learn everything you need to know about the program so you can decide if the Drama Method is the right choice for you before you buy it. Please click here website: https://www.rebelmouse.com/dramamethodreview/ ...

http://www.bestmattress-reviews.org/consumer-reports-2013-mattre

Easily, the article is actually the best topic on this registry related issue. I fit in with your conclusions and will eagerly look forward to your next updates. Just saying thanks will not just be sufficient, for the fantasti c lucidity in your writing. I will instantly grab your rss feed to stay informed of any updates.
best mattress 2013

tanks

Hay salam kenal dari saya terima kasih telah memberi kesempatan untuk berbagi tentang tutorial seo dan belajar membuat blog. Salah satu dari blog agar bisa memenangkan di mesin pencari seperti google adalah optimasi seo onpage, dengan benar agar blog Anda juga mempunyai peringkat yang bagus. Namun tidak cukup hanya optimasi seo on page dalam memenangkah sebuah artikel di perlukan juga optimasi seo offpage. Apa itu optimasi seo off page? seo offpage adalah mengoptimalkan blog dari luar seperti mencari backlink yang banyak dari situs dofollow atau blogwalking. Optimasi seo on page tidak lepas juga dari menulis artikel berkualitas, tanpa artikel yang bagus dan relevan sulit bagi mesin pencari untuk mengindex artikel Anda, jadi lumayan sangatlah penting artikel berkualitas itu. Oh iya mungkin Anda belum juga punya blog? bila belum silahkan daftar email google dulu sebelum membuat blog, namun bila Anda sudah punya email google, silahkan Anda membuat blog di blogger karena blogger itu gratis, lumayan buat pemula coccok untuk blog yang gratisan. Bila Anda sudah punya blog dan ingin blog Anda di jadikan bisnis perlu Anda membuat privacy policy khusus untuk bisnis. Dengan mempunyai privacy policy blog Anda akan terlihat profesional dan terpercaya, jadi jangan sampai Anda tidak membuatnya. Dalam bisnis agar bisnis Anda lancar tentu blog Anda harus menempati posisi halaman utama mesin pencari, jadi sebelum Anda memulai bisnis Anda lihat pesaing Anda dengan cara menganalisa seo komptitor Anda agar mudah Anda mengoptimasi onpage Anda dan blog Anda nongkrong di halaman utama mesin pencari horee. Kalau blog saya bukan untuk bisnis onlain, jadi saya hanya perlu membuat privacy policy untuk blog saja, agar pengunjung tahu kebijakan tentang pennggunaan blog saya. blog saya pun saya lengkapi dengan contact form untuk mempermudah pengunjung menghubungi saya, entah masalah apa saya akan tanggapi di contact form saya. Pernah juga di contact form saya ada yang bertanya tentang bagaimana cara mengetahui posisi ranking artikel di google dan saya jawab, cukup mudah kok. Ada satu lagi yang bertanya tentang membuat email yahoo dan sudah saya jawab juga, gimana apakah Anda juga ingin bertanya juga?

adsfhsr

growtopia hack
Ceci peut en fait être utilisé d'une manière plus complexe. «Les développeurs devront apprendre à mieux placer plus de l'expérience dans l'esprit et moins de celui-ci à l'écran», explique le développeur de jeux Moo Yoo, qui a travaillé à Moshi Monsters créateur Mind Candy va jusqu'à indépendante. «Je imagine une énorme demande pour les jeux sociaux très interdépendants et récits sociaux générés dynamiquement. Vous pouvez prendre l'exemple d'un jeu comme Farmville qui a donné le contexte et un sens à don un animal virtuel du monde réel. Un jeu de smartwatch pourrait être un système de propositions, les acceptations et refus - soit dans un dating sim ou un jeu de la diplomatie ".
growtopia triche

telling you that I truly

telling you that I truly enjoyed the top quality info you present to your visitors? Will be back again frequently to check up on new posts. conciergerie

dgsfhjsrhdsr

how to get free psn codes
At that moment is when Abe try to save his own skin from the stinging although this will have to face many dangers on his adventure to discover the heritage of his people.
get free psn codes

my review

The Girlfriend Activation System is one of Christian's most popular products that helps men not only find and attract amazing women, but ultimately turn them into loving, loyal, and long-lasting girlfriends.my review

http://eromax.co/

Mmm.. good to be here in your article or post, whatever, I think I should also work hard for my own website like I see some good and updated working in your site.
無料エロ動画

http://www.sleepjunkie.org/get-the-best-memory-foam-mattress-for

I should say only that its awesome! The blog is informational and always produce amazing things.
best memory foam mattress

hsrhstjdsr

Free psn codes
EH BILDU recalled yesterday that on Saturday presented "the 100 steps that will change Navarra", which includes "the main lines of the proposals for change that is unstoppable in Navarre".
psn code generator

memyfriends Me My Friends is

memyfriends Me My Friends is a daily blog that offers relationship tips and online dating trends to help singles make more meaningful connections. Please click here my webpage: http://memyfriends.com/ ...

http://www.sgdatingweb.com/gf

http://www.sgdatingweb.com/gfas-review-how-the-girlfriend-activation-system-attracts-women/ GFAS Review – How The Girlfriend Activation System Attracts Women. But those fast-talking pickup lines used in bars don't usually attract the highest quality women. A different approach... http://sgdatingweb.com/gfas-review-how-the-girlfriend-activation-system-... ...

website Kiii-TV 3 News is the

website Kiii-TV 3 News is the South Texas news leader for over 40 years, providing local news, weather and sports from the people you know and trust. Click here webpage: http://www.kiiitv.com/story/27971908/girlfriend-activation-system-review... ...

website

website voyance-retour-amour.com vous permet de contacter une équipe de voyantes et voyants au 0892 30 00 19. Disponibles 24h/24, nous vous parlons de votre sentimental, de votre amour, votre travail ou vos finances. A bientôt. Se il vous plaît visitez le site Web: http://voyance-retour-amour.com/ ...

Mit unseren hochwertigen und

Mit unseren hochwertigen und modernen Galerieschienen lassen sich Bilder sowohl zu Hause als auch in gewerblichen Räumen schnell, leicht und vor allem exibel aufhängen.Mit Galerieschienen brauchen Sie nie mehr Nägel in eine Wand zu schlagen...Aufhängesystem für Bilder

bsfhjsfrhsr

fifa 15 ultimate team coins
Specifically, are aimed at middleweight riders to be upbeat rhythms without neglecting damping in these shoes is remarkable thanks to PWRGRID + midsole.

randevu bayan Escort Bayan

randevu bayan Escort Bayan Modeller ve Escort Randevu Telefon Hizmeti...

courtisane.co.uk Courtisane

courtisane.co.uk Courtisane is a high class agency offering some of the most beautiful and alluring model and high class London escorts to our discerning clientèle. visit website: http://www.courtisane.co.uk ...

Adult dating

Adult dating Xxxadultmarket.com offers a wide range of choices to find the best free live sex cam, free adult dating communities, penis enlargement products and porn video series. We have the best available for you...all in one! Please click here site http://www.xxxadultmarket.com/ ...