| 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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Posts Tagged ‘quality control instructions’
Systems Engineering In Medical Device Design – Instructions, Part 3
Sunday, January 20th, 2013
Systems Engineering In Medical Device Design – Instructions, Part 2
Monday, January 14th, 2013| Last time we discovered that clearly written instructions are one of the desired end results of the Development stage of the systems engineering approach to medical device design. We learned that one of the objectives of these instructions is to make sure the devices are manufactured in a cost effective manner and with minimal defects during the Production stage.
Other instructions created during the Development stage are those addressing quality control inspections and testing instructions. The objective of the quality control department is to ensure that, during the Production stage, the end product has been assembled correctly, making use of the prescribed parts, and absent manufacturing defects. This end is achieved by virtue of the fact that the quality control department staff is usually not under the management of the engineering or manufacturing departments, therefore they are positioned to offer an impartial assessment of the production process. An undesirable side effect of quality control’s impartiality is that because they are not intimately involved in the design process, a great deal of collaboration must take place between them and design engineers to produce quality control instructions which meet objectives. To this end, many discussions must take place concerning subject matters as diverse as requirements for component dimensions, component material properties, and the proper assembly of parts. Next time we’ll continue our discussion on the Development stage by further examining how instructions are developed to ensure that the quality control department meets its objectives while performing inspections and tests during the Production stage. ___________________________________________
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