Medical Device Development - The Advantages of RTOS

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1 Getting Your Medical Devices to Market Faster, on Schedule, and at Lower Cost How Integrating GUI design with RTOS selection can enhance time to market and produce a more effective medical device Jerry Krasner, PhD., Chief Analyst March 2014

2 Copyright 2014 by American Technology International, Inc, 638 Main St., Ashland, MA All rights reserved. No part of this book covered by copyright hereon may be reproduced or copied in any manner whatsoever. Every effort has been made to provide accurate data. To the best of the editor s knowledge, data is reliable and complete, but no warranty is made for this American Technology International

3 Getting Your Medical Devices to Market Faster, on Schedule, and at Lower Cost How Integrating GUI design with RTOS selection can enhance time to market and produce a more effective medical device March 2014 Jerry Krasner, Ph.D., MBA You only need to do a few things right in your life so long as you don t do too many things wrong Warren Buffet Introduction: In 1931 Olaf Stapledon s book, Last and First Men, told the delightful story about a Martian invasion of Earth in which the Martians and denizens of Earth were oblivious to one another. The invaders from Mars, looking for resources (in particular diamonds), consisted of a cloud of microorganisms possessing radio telepathy and a distributed consciousness. They possessed a sophisticated culture, but in their search for diamonds, they looked right past the slow moving, slow communicating human inhabitants of Earth. Being an old-time warrior of the medical device industry with more than 40 years and twenty 510k applications, I recognize a familiar theme in Stapleton s story. It shines an interesting light on today s medical device industry. Most medical device developments still use Microsoft OSes notwithstanding the availability of faster, lower power OSes that demonstrate a faster time to market, require fewer engineers, and experience lower design costs. I see the same blindness when it comes to commercial versus free Linux and with open source software in general. Medical device manufacturers assume the claims by Microsoft and open source evangelists that commerical OS vendors and their licensing fees are exhoribitantly expensive in comparison to free development seats without any tangible proof. We will provide data from actual developments to refute these claims. Like Stapleton s slow moving and slow communicating humans, many medical device developers and their managers remain oblivious to proven technologies that can enhance their design experiences, create lower costs of development, and provide for better audit trails should they be needed for CDRH review.

4 In a recently updated paper entitled Critical Issues Confronting Medical Device Manufacturers, Their CEOs, CFOs, Managers and Developers, EMF took the reader through steps designed to cover the bases in order to minimize recalls and to have documentation to use to defend against a CDRH audit. In this paper, we wish to acquaint medical device manufacturers with currently available technologies used effectively in other vertical marketplaces. These technologies speed the development process, lower the cost of development, and better integrate new technologies such as graphical interfaces a rising trend in medical devices in a way that speeds graphical user interface development and deployment. In this paper we will consider the following: Why choosing the OS most suitable to the application can produce significant savings Factors that should be considered when adopting new technologies such as graphical userface interfaces into medical devices

5 Choosing the Most Suitable RTOS By providing a range of choices and limiting responses to only four characteristics, we are able to create a list of the factors most important in the developers decision-making process. The result is presented in Table I. Acquisition cost 43.4% Microprocessor support 42.1% Availability of source code 40.3% Real time performance 36.0% Compatibility with our development tools 32.2% Includes good development tools 28.6% Reliability 27.0% Availability of perpetual license 23.0% Host platform support 20.6% Availability of required middleware or networking protocols 20.3% Compatible with Linux 16.2% Availability of professional services (porting, integration, certification) 15.4% Quality of support 14.7% Royalty cost (production licenses) 14.4% Safety certifiable (DO-178B/C, IEC 61508, FDA, etc.) 14.1% Provides device drivers and/or board support packages 13.6% Must be free (for both development and production) 12.8% Must be open source 12.3% Memory constraints 11.5% Security 11.2% Table I: Most Important Characteristics used in RTOS Buying Decision Medical patient monitoring is not a mission-critical design. The fastest response times are measured in milliseconds and critical alarm design can compensate for any systems failure. Nonetheless, it was interesting to see: 1) Many widely used RTOSes did not exhibit the best results in time to market or design outcomes; 2) Certain RTOSes, e.g., Express Logic s ThreadX, had better time to market, fewer designs completed behind schedule, and a lower cost of development than more established RTOSes (e.g., Windows CE, VxWorks, LynxOS) as well as Linux and open source software 3) Commercial Linux outperformed open source software 4) These comparisons have been calculated year-over-year from 2007 through 2013 with the same outcomes. (Data is shared with subscribers to the EMF Market Intelligence Program.)

6 The unique EMF Executive Dashboard enables one to simultaneously look at developer responses to those that reported using Microsoft CE, ThreadX (chosen as a commercial RTOS example), commercial Linux, non-commercial (free) Linux, and open source software. From these filters, one can interrogate the 2013 EMF Survey of Embedded Developers to determine the: Number of software developers per project Average time from project start to shipment (time to market) Percentage of developments completed behind schedule, including the amount of the delay in months Percentage of developments cancelled and time elapsed before cancellation From these data, one can calculate the average number of developers per project, the number of developer months lost in schedule overruns, and the number of developer months lost to cancellation. From these data, one can calculate the total number of developer months per project. With this, one can determine the comparative total cost of development among commercial RTOSes (choosing ThreadX and Windows CE), commercial and free Linux, and open source software developments. Table II presents these data representing the a cross-section of all industries and vertical markets EMF Survey Data Open Comm Non- Comm Microsoft All Respondents Ind ave ThreadX Source Linux Linux CE Devel time Months - Start to Ship % behind schedule 47.0% 36.9% 45.1% 47.5% 46.7% 38.1% Months behind % cancelled 11.2% 13.4% 10.9% 11.7% 11.2% 11.5% Months before cancellation SW Developers/project Average Developer months/project Developer months lost to schedule Developer months lost to cancellation Total developer months/ project At $10,000/developer month Average developer cost/project $2,043,300 $877,200 $2,508,000 $2,244,600 $3,367,300 $1,901,900 Average cost to delay $262,542 $75,276 $308,484 $256,215 $426,978 $202,692 Average cost to cancellation $72,442 $41,915 $91,124 $73,289 $109,894 $67,298 Total developer cost/project $2,378,284 $994,391 $2,907,608 $2,574,104 $3,904,173 $2,171,890 Table II: Worldwide Comparative Costs of Development

7 It is clear from Table II that developers using commercial OSes (ThreadX and Windows CE) got to market faster, required fewer developers per project, experienced lower costs of development, and had lower costs associated with delays than what was experienced with Linux or open source developments. Also, it has been clear, year over year that commercial Linux developments cost less than non-commercial Linux developments. Table II makes it clear, nonetheless, that developers using RTOSes other than Microsoft CE can create additional savings. In this case, the use of CE was twice as costly as that of ThreadX. Since many medical device developments today use ARM processors, we also looked at these same factors in ARM developments as presented in Table III EMF Survey Data Open Source Embedded ARM Microsoft ARM Developers ThreadX Software Linux All Users CE Devel time Months - Start to Ship % behind schedule 23.5% 41.0% 37.8% 43.4% 37.2% Months behind % cancelled 7.4% 11.1% 6.0% 9.6% 12.2% Months before cancellation SW Developers/project Average Developer months/project Developer months lost to schedule Developer months lost to cancellation Total developer months/ project At $10,000/developer month Average developer cost/project $501,600 $1,165,600 $705,600 $797,300 $1,625,600 Average cost to delay $26,790 $134,890 $71,971 $107,589 $188,976 Average cost to cancellation $9,701 $45,910 $15,456 $25,085 $60,427 Total developer cost/project $538,091 $1,346,400 $793,027 $929,973 $1,875,003 Table III: Worldwide Comparative Costs of ARM Developments Comparing Tables I and II, it is interesting to note that ARM developments are less costly than those that are industry wide. Yet here, we see that embedded Linux (combining commercial and non-commercial) performs significantly better than Windows CE ARM developments. ThreadX is still 50% less costly than embedded Linux.

8 While some medical device developers may argue that free software is the preferred route, it is the fundamental tenet of capitalistic endeavors (sort of a technology Darwinian clearing house) that such arguments are settled in the technology marketplace. Clearly, data reveals that both cross-industry results and ARM development results show that commercial RTOS use significantly reduces project cost. Many developers simply compare the face value of the cost of a development seat or licensed product without looking at the overall ROI. Short of having access to definitive data, this is understandable. In this paper, we have presented data developed from years of developer responses to EMF surveys. We encourage developers and project managers to consider this data in making their decisions regarding the selection of development tools. The cost savings in development costs and time-to-market are but the tip of the iceberg. Being late to market increases development cost, and MORE SIGNIFICANTLY, reduces market share. It can make the difference between a profitable, successful product and an also-ran product that loses money. The cost of being late to market far outweighs the development cost and any savings gained from use of a free OS solution. The OS may be free but the total cost of development certainly is not, and the cost of being late to market is has far graver consequences. Relying on the free OS can be penny wise and pound foolish. Trends In Medical Device Development Time to Market is generally accepted as a critical element of a product s potential for success. But after introduction, even after deployment in a medical facility or at a patient s home, other factors become equally critical. At a recent AAMI conference, a CDRH spokesman commented that more than one-third of medical device incident reports involved user error, and more than one-half of recalled devices could be traced to user interface design. Such incidents and recalls are costly for device manufacturers. As user interfaces become more sophisticated, the focus on medical usability issues becomes more critical. Today s tools for the design and development of graphical user interfaces (GUIs) for medical devices can go a long way toward reducing the incidents and recalls that result from user error. GUI development is an integral part of any human operated medical device development. Considerations of how systems can be designed to work well with medical professionals is a key component of the safety, efficacy and ultimate success of how a medical device is deployed within a patient centric application (be it patient monitoring, dialysis, ultrasound, ambulatory or other applications). These human factor considerations are a key component of the CDRH s 510k pre-market application process.

9 In architecting and conceptualizing the medical device, the GUI is a separate but essential part of the application software for the device and has to be integrated with the rest of the application. Hence, an ideal GUI development environment is one that must be closely tied to the chosen operating system, and it should not dilute the benefits of the chosen RTOS. Ideally, the GUI development tools offer similar time-to-market benefits as the RTOS, and if both are provided and supported by the same vendor, those beneficial characteristics are more likely to be realized. It is essential that the user interface be structured with as much flexibility as possible as the product goes through its design iterations. Developers need the ability to prototype as well as the ability to test the GUI with end-user input to ensure that the final product will be effective and its operation and interpretations are clear and easy to use. To ensure more rapid product completion and deployment, the combination of RTOS and GUI application development must be sufficiently flexible to permit rapid prototyping, field testing and evaluation, and software modification. Thanks to the explosion of opportunities that started in smartphones, interactive, intuitive GUIs have become commonplace in medical devices. The need for these interfaces to be intuitive, clear, and flexible has resulted in the need for advanced tools to simplify their development. Most embedded system programmers are not LCD specialists and do not want to program these displays at the lowest level, which involves constructing individual graphical shapes and objects ( widgets ). Instead, to speed time to market, most developers use a library of routines that manage the GUI details. Express Logic s GUIX is an example of a modern development framework that allows developers to describe the GUI elements at a high level of abstraction. Such frameworks help developers enhance programming Figure I: Sample Medical GUI productivity and avoid many errors. They typically include a rich library of widgets tailored to help developers construct whatever GUI they envision. GUI functions can be called from C application programs, and the framework performs all the necessary drawing functions to produce a clear, interactive GUI on LCD screens of various sizes and resolutions.

10 Today, such GUI development tools are available that target ARM 32-bit MCU and MPU architectures, including Cortex-M3, M4, A8, and A9, in medical devices (see Figure I), consumer electronics, and industrial control equipment. Interestingly, GUI designs often are created by graphics artists, not programmers. These designers require a tool that doesn t involve programming, yet that can produce an embedded GUI. Fortunately, most GUI tools include a companion PC-based application that enables WYSIWYG rapid prototyping of GUI designs (as shown in Figure II). With such rapidprototyping tools, the graphics designer can select, drag-and-drop, and resize images, backgrounds, widgets, and other elements of a powerful GUI without having to write a single line of code. The tool generates the code necessary to implement Figure II: GUI Design Tool the exact GUI design constructed on the PC. The generated code then can be dropped into the application by a developer and executed on the target system. Conclusion There is no longer a need for developers to waste time implementing GUIs at a low level when an effective and easy to integrate means is available. Likewise, it is now possible for graphics artists with no programming background to design embedded GUIs for use in medical, consumer, and industrial devices. It makes sense that such tools can enhance a development s time-to-market. Just like other development tools and RTOSes, GUI development tools should be evaluated based on their contribution to ROI, not by cost alone. Together with best practices in other phases of product development, the best development tools will give medical device manufacturers their best chance of achieving success in the marketplace. The data presented in this paper enables informed choices, and can help manufacturers give their products the best chance for success.