Mechatronic medical devices are an important historical innovation. Hardware, combined with information-driven software processes, offers increasingly sophisticated functionality, but it also creates important problems with quality. Integration of the engineering work of various hardware, software, and human factors disciplines is a major challenge. Validation and verification testing are about avoiding mistakes in engineering development, deployment, and maintenance. Human factors practitioners call these mistakes errors. There are two fundamental rules regarding errors:
•Rule 1—All errors are made by humans
•Rule 2—All errors are experienced by users.
One categorization of errors of critical importance to engineers is system use versus individual user errors. Mechatronics maturity is a measure of how good you are at avoiding system use errors. Testing is necessary, but never sufficient.
The specific processes embedded in your organization help us estimate mechatronics maturity ... and that is a predictor of new product development (NPD) quality, which is one reason why FDA believes that quality system management audits have value. From a business perspective, a low maturity NPD process is more costly and less time efficient; a high maturity NPD process is very cost and time efficient. Even if your only motive is maximizing profit, not maximizing your organization’s mechatronics maturity is a waste of your resources.
An important historical innovation in healthcare has been the advent of mechatronic medical devices—devices that integrate sensor and effector mechanical and electrical hardware (HW) with information-driven software (SW) processes into a potentially synergistic whole, offering increasingly sophisticated functionality. They range the gamut from simple positioning systems, to infusion pumps, to robotic surgical devices and healthcare information technologies.
While the use of mechatronics offers enormous potential for increasingly sophisticated functionality, it also presents equally large quality problems with interdisciplinary development, deployment, utilization, and maintenance. These are not merely technical issues (e.g., promoting integration of HW and SW development by automatically generating a new hardware abstraction layer with each HW revision), but also organizational issues (e.g., preventing development from occurring in independent silos) and project management issues (e.g., emphasizing and prioritizing quality milestones over schedule and budget milestones). How an organization deals with the HW, SW, and all-encompassing human factors (HF) issues may be viewed as a measure of mechatronics maturity.
Why HF issues? In the final analysis, all products, processes, and services exist solely because they are perceived to have utility or esthetic value for some humans. All engineered systems require humans. Yes, even isolated, automated, unsupervised systems require humans; they are called installers and maintenance personnel.
Also, what we engineers think of as the “system” is really not. The functioning system is the combination of our product, process, or service plus all the humans (operators, maintainers, etc.) and their organizations; without all these humans and their organizations, our “system” cannot function and can have no value.
Quality exists only in the eyes of the human stakeholders and their organizations. Quality may be defined as: the degree to which the system satisfies the needs, wants, and desires (NWDs) of ALL the stakeholders, which means the degree to which you obtain a good result that is good enough, though not necessarily the best, for each of all the stakeholders. From this simple definition, all other measures of quality can be derived.
The four top-level NWDs of all stakeholders are: 1) safety, 2) effectiveness, 3) efficiency, and 4) stakeholder satisfaction (SEES). For medical devices, this means products that are safe and effective, efficient to produce and use, and satisfying to all stakeholders, including both individuals and their organizations
This article explores mechatronic medical devices, errors, the five stages of mechatronics maturity, and comes with fifteen references. Click to read "Medical device mechatronics maturity adds to device success," which originally appeared at sibling publication Medical Electronics Design.
About the author
G.M. Samaras is a biomedical scientist/engineer currently in private practice (Pueblo, CO). Trained as an electrical engineer, he has doctorates in physiology and industrial engineering (engineering management); he is a licensed professional engineer (PE), board-certified human factors engineer (CPE), and an ASQ-certified quality engineer (CQE). He has a number of biomedical patents and publications in physiology and engineering (hardware, software, human factors, and quality). He has worked at the FDA/CDRH as a reviewer & manager, he was a medical school and engineering graduate school professor, and founded an engineering firm that he ran for a decade.
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