Medical device software comes under the microscope
16 November 2012
Technology plays an integral role in driving medical
innovation forward. The last few years have seen an even larger increase
in the advancement of software in medical devices.
According to the
Institute of Medicine (IOM), medical device manufacturers rely more than
ever on the software to build new devices and to add new capabilities.
More than 50% of existing medical devices depend on software in some
form or another — the software is either embedded in the devices or
plays an important role in the production of the device. Companies
that lead the medical device market in innovation and efficiency
rely heavily on software for new product lines and enhanced
As a result, the complexity of software in these devices has
steadily increased. The benefits of software, however, come with the
cost of risk of failure due to the presence of defects — there is
typically a strong correlation between code complexity and the
number of defects in the software. The safety-critical nature of
medical devices requires that a variety of testing methods be
employed to ensure that defects don’t slip through development and
end up risking the lives of those who use them.
To ensure proper verification and validation of medical devices, a
strong emphasis is placed on regulatory oversight and device
approval before market release. However, in a recent report by the
IOM titled Medical Devices and the Public’s Health: The FDA 510(k)
Clearance Process at 35 Years, the group evaluated the 510(k)
process and recommended an overhaul of the approval process.
Given the increasing use of software, the IOM committee reported on
the increasing uncertainty introduced by device complexity as well
as potentially unsafe interactions with other software systems and
suggested that the Food & Drug Administration (FDA), which is
responsible for regulatory oversight on medical software development
process and testing in the US, review and update its guidance on software
Device manufacturers met these suggested regulatory overhauls with
concern. According to them, introducing new regulations on the
industry would stifle innovation, increase costs, and slow down the
process of bringing new and valuable devices to the market.
the past, the FDA has done its part when it has recognized a need
for introducing new guidelines or updating existing ones. For
medical device software, the FDA introduced the guidelines in the
form of General Principles of Software Validation (created in 1997,
Such guidelines serve to help the device
manufacturers put in processes and take specific actions to validate
the software that helps operate medical devices.
Most recently, the
FDA started work on drafting a guidance for mobile medical
applications after acknowledging the recent growth in the use of
mobile device applications for improving and facilitating patient
care. These guidelines contain recommendations for software
verification, defect prevention, software validation after changes
to a code base, independent review, and developer testing.
manufacturers take guidelines and modifications to existing approval
processes very seriously and use tools such as static analysis to
ensure their development process aligns with federal requirements.
Since 2006, the use of static analysis to test code within
traditional software verification and validation (V&V) processes has
seen a dramatic rise. Modern static analysis can discover complex
defects in the code by simulating every possible execution path of
the program without the need to actually execute the code.
Additionally, by focusing on ‘run-time defects,’ new static analysis
technologies evaluate more of the intricate interactions within code
bases. A simple example of this is tracking the values of variables
as they are manipulated down a path through the code or the
relationship between how parameters of functions are treated and the
corresponding return values.
To analyze code with this additional
level of sophistication, mature analysis solutions combine path flow
analysis with inter-procedural analysis to evaluate what happens
when the flow of control passes from one function to another within
a given software system. The entire analysis is automated and does
not require a substantial modification to the existing development
The use of static analysis has given rise to building
long-term best practices in the software development process for
medical software. A good Governance, Risk, and Compliance policy
that builds on the strengths of automated code testing with static
analysis can make medical devices safer and the development process
more efficient. Such policies allow development organizations to
define and test code against compliance and regulatory requirements
to manage development risk throughout the development process.
It also allows the organization to be proactive, prescriptive, and in
control of the quality and safety of the software and devices they
It doesn’t matter whether you’re a consumer, a device
manufacturer; software is essential for creating breakthrough
devices that improve the quality of people’s lives. However, risk of
failure and complexity inherent in software are two challenges that
medical device manufacturers must be prepared to tackle.
The rapid evolution of devices may even increase the importance of bug-free
software not only to improve the devices’ efficiency but also to
reduce the security threats. The question of security is crucially
important as more devices incorporate features that require
connectivity for control, reporting and monitoring.
An article in The Economist
talked about the possibility of reprogramming an implantable cardioverter defibrillator either to unexpectedly withdraw therapy
or to produce unnecessary shocks . The magazine also quoted Dr Fu, a computer science professor at
the University of Massachusetts, who argued that, “Many
manufacturers do not have the expertise or the willingness to
utilise new tools being developed in computer science.”
Fortunately, development testing solutions together with best
practices are able to prevent security breaches and ensure the
integrity of safety-critical code bases.
1. Institute of Medicine:
2. Medical Devices and the Public’s Health: The FDA 510(k)
Clearance Process at 35 Years