Posts Tagged ‘commercial production’

Systems Engineering In Medical Device Design – Utilization

Sunday, March 24th, 2013

      Who hasn’t finished a project, only to discover that you’d done something wrong and the whole thing would need to be redone?   Perhaps you hadn’t checked your work along the way, confident that all would be well in the end.   Imagine the costs involved if this scenario were to take place on a commercial production line.   The Systems Engineering Approach to things helps ensure this doesn’t happen.

      Last time we wrapped up our discussion on the Production stage of the systems engineering approach to medical device design, and today we’ll cover the final stage, Utilization.

      The Utilization stage marks the point at which the medical device has been sold and is in actual use in the marketplace.   Despite the fact that the product has at this point undergone many reviews and revisions and a great investment has been made into deciding whether or not to put it into production, changes can still take place in its design.   Markets aren’t static, and products may be made to change due to stakeholders’, that is, those with a vested interest, changing requirements, whether those are aimed at further cost reduction, or perhaps to implement innovations to make the product more appealing to end users.

      Other reasons for change may be initiated by the sales and marketing departments.   They keep their fingers on the pulse of consumer trends, and they may want the design modified according to market research and feedback they receive from dealers, service technicians, and end users.

      For example, the sales staff may have been apprised by end users that the keypad to their electronic muscle stimulating device needs modification. Patients have voiced they would prefer to here a clicking sound when depressing the buttons, in order to receive some auditory feedback.   In addition, distributors of the device reported that although the electronic stimulators were functioning as intended, end users didn’t like the feel of the buttons.   The lack of tactile feedback often led to confusion because they weren’t sure whether they had depressed the button or not.

      Another interesting discovery concerning lack of feedback was that product service technicians were reporting premature wearing out of the keypads.   Absent the satisfying click sound, users were inclined to push on the pads too strenuously, which drove up warranty service costs.   The medical device manufacturer’s stakeholders are always concerned with costs, and increased service costs definitely raise the red flag.

      Considerations like these typically arise after a medical device enters the Utilization stage.   Fortunately, the objective of the systems engineering approach is to ensure that stakeholders’ needs are met in view of ever-changing requirements, even after the device has entered the marketplace.   No matter what may happen during the life cycle of a product, the systems engineering approach is used every step of the way, from the Concept stage through to Utilization.

      That ends our discussion on the systems engineering approach to medical device design.   Next time we’ll begin unraveling some of the mysteries and misconceptions behind patenting inventions.

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Systems Engineering In Medical Device Design – Production, Part 1

Sunday, February 24th, 2013
     Done any remodeling lately?  If you have, you’ve been faced with countless choices regarding design and materials.  Even a relatively simple decision such as putting in hardwood flooring requires many considerations.  What type of wood?  What grade?  How about the stain?  Should it be factory stained and sealed, or should the flooring be installed by single board, then stained and sealed in place?  Ultimately, your decision is based on your requirements with regards to cost, durability, and personal style.

     Now imagine the decision making process that is required to produce a medical device.  We’ve been discussing this complex process during our series on medical device design utilizing the systems engineering approach, a systemized approach to product development, design, and manufacture that is used within many manufacturing arenas.  Its objective is to relate the requirements for manufacture, regulatory compliance, sale, use, and maintenance of the product to specific design criteria for functionality, durability, and safety.  By doing so, the systems engineering approach ensures that the product meets or exceeds all requirements.

     Last time we wrapped up our discussion on the Development stage of systems engineering by discussing field testing of medical devices assembled during Preproduction.  Problems encountered during this phase result in a comprehensive review of the device design and instructions.  When all issues have been resolved, things move on to the manufacturing phase and full commercial production.

     During the Production stage, engineers make continual assessments of the manufacturing process and ongoing adjustments are made to the device design and manufacturing protocol as necessary, this due primarily to changing stakeholder requirements regarding cost reduction.  In the competitive marketplace, cost reduction is a never-ending quest to maintain profitability in view of changing economic and market conditions, and this must be done without compromising the quality, safety, and effectiveness of the device.

     For example, suppose a medical diagnostic imaging machine was designed to be fitted with a machined metal gear in one of its mechanisms.  The manufacturer specifies that a $10 decrease must be made in production costs so it can continue to be sold at an acceptable profit margin.  After reviewing the design, engineers discover that substitution of a molded plastic gear would reduce manufacturing cost per machine by $12.  This is a common scenario, as plastic parts are often substituted for metal to save on cost.

     Plastic versus metal?  How can that be an acceptable swap?  In many cases, it can be.  Mechanical stressors are analyzed, and if the plastic gears meet durability requirements as well as their metal counterpart, they are substituted.  During the Preproduction phase these plastic gears are used in both lab and field testing, where they are put through the rigors of real world use.  If they perform acceptably, they are made a permanent part of the device’s design and used in commercial production.

     Next time we’ll continue our look at the Production stage to discover another way that systems engineering can facilitate cost reduction to meet stakeholder requirements.

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medical device design