Medical procedures

Unicut Precision (01707 331227) was approached three years ago by a European medical device company to quote for the production of components for a new mechanical device to provide the needle-less administration of insulin to diabetes sufferers. Jason Nicholson, joint managing director of the Welwyn Garden City company, reflects: "Although most of the parts were very complicated, involving difficult materials, because of our continuous investment policy in the latest turn-mill technology and support infrastructure, our ability to produce these parts by combining multiple operations into single cycles was all part of a normal day's work." Unicut consequently won the contract, but, today, most of the components being produced as part of the initial £230,000 contract – involving 10,000 sets of 14 parts – bear no resemblance to the original quotation drawings. Mr Nicholson explains: "Over the past two-and-a-half years, we have worked closely with this Dutch customer, giving design-for-manufacture advice to help develop the components. In addition to general production engineering input, some parts were redesigned as two separate items to simplify production. However, due to the capability of our Citizen sliding-head (Citizen Machinery, 01923 691500) and Miyano fixed-head (Miyano UK, 01384 489500) turn-mill centres (25 in total), others were combined into more complicated single parts in order to ensure geometric relationships of features, simplify the final assembly and reduce production costs as well, as guaranteeing function of the critical needle-less device." As part of its customer support service, Unicut directors also provided advice on material, changes to material specifications for machinability, as well as protective coatings to prevent wear on critical components, and ensure long-term accuracy of the device and to improve performance. During this initial period, the companies worked closely together on prototype development. This process even saw the making of samples to maximum, mid and minimum tolerances, so that product development trials could be performed to ensure that functionality of the assembled device would never be compromised. Image: Joint managing directors Jason Nicholson (left) and Charles Kenny (right) MORE MEDICAL ATTENTION Unicut has worked for several years with the medical sector and almost 12 months into the Dutch project, it was approached by a UK company to work on the development of an electronic-assisted device to perform dial-up dosage and needle-less injection of other types of drugs. According to Unicut's joint managing director Charles Kenny: "This was a completely different ball game, requiring even stricter quality systems and additional levels of traceability. While the Dutch product involved 14 parts, the UK customer's device (that is now under contract as well) comprises 12, with an initial production of 20,000 sets, predicted to rise to 50,000 units/year." The demand for needle-less drug administration devices is predicted to rise rapidly, due to their ability to deliver, in a fraction of a second, a precise micro-thin stream of insulin through a specially designed precision orifice at high velocity that penetrates the skin and is deposited into the subcutaneous (fatty) tissue. They eliminate risk of accidents from needle stick injuries and contamination, are ideal for people who dislike injecting with needles or who can develop skin problems, and remove any disposal problems associated with a sharp object. Says Mr Kenny: "We have served the medical, aerospace and telecom sectors with very demanding components and been involved in many special projects, but we have never had to go to such levels of procedural systems, measurement and quality." To which Mr Nicholson adds: "Due to our year-on-year growth of between 15 and 25 per cent, and a policy of continuous investment in equipment, people skills and sustained training, we were able to adapt and absorb the customers' requests to changes in our methods of working. But we really had to step up a gear to meet the challenges that both customers put to us." Key to the success of this prototyping and pre-production work was Unicut's ability to take total responsibility on both projects for outsourced processes, such as specialist deburring, heat treatment, wire EDM, plating and surface finishing, so that parts could be delivered directly to the customer, ready for assembly. As the projects developed towards pre-production, both Unicut directors reviewed their proven production and quality procedures, in order to create a seamless transition. As part of the investment, Colin Luke was recruited as quality manager and Melanie Jones as purchasing manager, while two additional machine setters and two Citizen K16 sliding-head lathes were installed to free up production on the higher specification Citizen M32 machines and a Miyano BNJ-42 fixed-head turning centre. A programmable Dürr component wash (Geo Kingsbury, 023 9258 0371) was upgraded to the latest specification and a cleanroom built. Training also became a key issue to ensure all staff involved were aware of and understood the demands each job would present and be certain they could respond positively. Image: The company's heavy investment in modern technology impressed SYSTEMS UNDER REVIEW Returning to the soft issue of quality, however, Mr Kenny points out, quality control and systems within Unicut were critical in both projects. "We had to comply with one customer's Install Qualification (IQ), Operational Qualification (OQ) and Part Qualification (PQ) standards," he says. For this, both Unicut directors had to present to a team from the customer how they would control the production process and apply full traceability from material order to component despatch, which, according to Mr Nicholson, the company's DataTrack production control and scheduling management system (Prospec Systems, 08456 345931), with minor modification easily provided the level of up-to-date information the customer sought. To satisfy the IQ requirement, Unicut had to furnish details on the type of machinery and equipment being used, its history and service records, procedures for programming, tooling and inspection, and provide documentation covering record-keeping, including usage, resetting and tooling records, capability studies, details of the personnel involved, health and safety compliance, plus environmental and risk assessment. PQ covered set down procedures, works order and stock control, production records (especially on outsourced processes), inspection routines, gauge control and reporting procedures. For first-off, the initial five components had to be 100 per cent inspected for every drawing detail, while any production improvements and changes of process had to be documented. Regular process capability studies were listed under PQ procedures, with reporting and actions taken that enabled track-back and situation recovery disciplines to be initiated, should any parts be found not to comply. As Mr Nicholson maintains: "Our extensive use of non-contact, video-based measurement, with its automated reporting, has proven very beneficial to the inspection and recording of the majority of component feature dimensions. It also enabled almost immediate electronic feedback to be provided to the customer for discussions over quality and design issues, providing detail and visual measurement analysis and fully automated SPC data capture, with tabulation at the touch of a button. "This saved us hours of almost endless checking, eliminated any bias and subjective debate, and certainly impressed the customer by the amount of detail we could provide. This also helped to quickly build confidence with the customer concerning the levels of consistency that we could maintain over the production of a batch of parts," he concludes. First published in Machinery July 2009