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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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Posts Tagged ‘Utilization Stage’
Systems Engineering In Medical Device Design – Preproduction, Part 2
Monday, February 11th, 2013| Last time we began our discussion on Preproduction, the final aspect of the Development stage of our systems engineering approach to medical device design. This is the point at which a small amount of devices are put into actual production, then evaluated for full production possibility. It is also the final juncture at which problems will be evaluated and corrected before full commercial production can begin.
Once the medical devices produced during Preproduction are assembled, they’re subjected to rigorous testing in both a laboratory and the field. This testing is necessary to see if stakeholder requirements are satisfied. At this stage devices constructed en masse on the factory assembly line are compared to prototypes built by hand by design engineers earlier in the Development stage. During Preproduction laboratory test data is gathered and analyzed by engineers to assess how the device will hold up during actual use. Real-life conditions are simulated in the lab environment to facilitate this process. For example, lab testing of a Preproduction kidney dialysis machine can determine whether its blood pump flow rate falls within acceptable range during hundreds of hours of operation. Other factors, such as durability of materials are evaluated during lab testing. In the case of the dialysis machine, there is a component called a dialyzer that filters toxic waste from blood. Over the duration of the lab test, the material used in the dialyzer filter membranes would be inspected and evaluated for durability. Next week we’ll conclude our discussion on Preproduction to see what happens when testing is moved outside the lab environment into the field. ___________________________________________
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Systems Engineering In Medical Device Design – Preproduction, Part I
Monday, February 4th, 2013| If you’ve been following along with our blog discussion on the systems engineering approach to medical device design, you should by now be convinced that instructions are important. In fact, the meticulous instructions produced during the manufacturing, operating, and maintenance phases of the Development stage are also crucial to later stages, that of Production and Utilization. Let’s finish up our discussion on the Development stage by taking a look at its final aspect, Preproduction.
The Preproduction aspect is instrumental to nipping potential problems in the bud before the medical devices go into actual production. In the initial Preproduction stages, systems engineers coordinate with the manufacturing and purchasing departments within the company as well as outside suppliers. The goal is to acquire all parts and equipment necessary to build a limited number of medical devices on the assembly line. Subjects such as preference in molded plastic components, motors, gears, pumps, springs, electronic components, circuit boards, wire, and tubing are discussed and agreed upon. Vendors are assessed with regard to their ability to produce parts when they are needed and that meet design specifications, satisfy quality requirements, and have costs that fall within budgetary constraints. The assembly of Preproduction devices provides an opportunity for systems engineers to validate manufacturing and quality control instructions and assess the device design with regard to manufacturability, meaning, the extent to which devices can be manufactured with relative ease, at minimal cost, while maintaining maximum reliability. Devices manufactured during this aspect of the Development stage serve as a test. Are instructions clearly written? Do the device parts fit together as they should? Are parts strong enough to withstand the assembly process? Can the devices be assembled as quickly and easily as expected? If the answer is “no” to any of these questions, then the device design and instructions must be returned to the design engineers and technical writers. Heads come together to rehash things and work out the bugs. Next time we’ll continue with the Preproduction aspect of the Development stage to see how laboratory and field testing enables systems engineers to shake out any more bugs from the medical device design, operating instructions, and maintenance instructions. ___________________________________________
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Systems Engineering In Medical Device Design – Instructions, Part 4
Sunday, January 27th, 2013| Last time we wrapped up our discussion on the development of quality control instructions for use during the Development stage of the systems engineering approach to medical device design. These instructions are used to guide quality control inspection and testing during the Production stage. Now let’s continue our discussion on the development of instructions for the Utilization stage, the stage when the medical device is actually put into operation by the end user.
In the systems engineering approach to medical device design, design engineers must work closely with technical writers, those responsible for writing operating and product service instructions. The objective here is to share the engineering staff’s intimate knowledge of the medical device’s design with the writers in order to ensure that instructions are clearly written, comprehensive, and follow a logical progression. Instructions must be written so as to be easily understood by lay people outside of the engineering profession and medical device industry, because most of the individuals using the device will be healthcare professionals and service technicians, individuals lacking a background in engineering or medical device development. Instructions are not only meant for the eyes of end users. They are also subject to review by governmental agencies. This fact acts as a safeguard to ensure device compliance both with regulatory requirements and industry standards as regards cautions and warnings. For example, instructions may be required to caution the user to allow the device to warm up for a certain period of time before use to avoid patient discomfort when coming into contact with cold metal. Instructions might also warn against a harmful interaction if the device is used in conjunction with other devices. For example, an electronic muscle stimulator may send electrical pulses into a patient’s body that can interfere with the operation of their heart pacemaker. No doubt this is something that the operator of the device and the patient would want to be informed of. At this point our medical device design has been completed, and instructions and procedures written, but the Development stage is not yet complete. Next time we’ll continue our discussion on this stage to see how a systems engineering step helps us to be safe rather than sorry after full production of the device has begun. ___________________________________________
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Systems Engineering In Medical Device Design – Instructions, Part 3
Sunday, January 20th, 2013| Last time we looked at the objective of the quality control department in the Production stage, that being to ensure that the end product produced fits all requirements. We learned that to meet this objective a great deal of collaboration must take place in the Development stage between quality control staff and design engineers in order to produce a complete set of instructions for quality control inspection and testing. Now let’s see how these instructions are developed.
Inspection and test methods are devised by the quality control department to ensure that a completed medical device lives up to its intended use. What good is a diagnostic imaging machine that doesn’t provide accurate internal views of a patient’s body? Or a heart defibrillator that sends electrical energy pulses to a patient’s heart muscles when it’s not supposed to? Quality control instructions are developed to guide inspection and testing methods so they’re performed correctly and consistently during the medical device Production stage. The objective is to catch problems before they occur. For example, it can be specified that the plastic body components of a medical device be visually inspected after they are received from an outside vendor to check for undesirable defects, such as the presence of burrs, cracks, or non-uniform coloration. If anomalies are discovered, they’re documented, and the components are rejected. In other words, they are barred from being used in the assembly process. Quality testing methods are varied. They may involve hooking up the completed medical device to test instruments to simulate all possible modes of operation and any anticipated glitches that may occur during testing. While hooked up, the device’s operation is measured against key parameters to ensure that all is working well, and the data gathered is recorded and analyzed to see if operation is within normal limits. For example, an electric multimeter could be connected to the power cord of the device to measure how much electrical current is being drawn from the wall outlet during operation. If current drawn is too high, it may be indicative of a defective electrical component, and an in depth examination would follow. Generally speaking, if test measurement parameters do not fall within acceptable limits as determined by previously established stakeholder requirements, then the medical device will be rejected by quality control. It will then be sent back to the manufacturing department, along with a detailed inspection and test report explaining why it was rejected. At this point the rejected device is either reworked or disposed of entirely. Next time we’ll continue our discussion on the development of instructions for the Utilization stage, the stage where the medical device is actually put into use by the end user. ___________________________________________
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