Fitting Devices to the Patient with Machining
Ted Driggs, Program Management Principal Engineer at Okuma, was a part of the staff written article, “The Fine Art of Machining.” He took time to present a full array of responses that were not able to be included in the article, so they are presented here.
Q: What emerging materials are ideal for machining?
Driggs: Likely a turn from metallic in the future once the science catches up to the device functional requirements
Q: How does machining stand-up vs. other component fabrication techniques for medical devices?
Driggs: Unless we can go from raw materials to net size and finish without any metal working, machining is a necessity. The tolerance requirements for form, fit and function of the medical device predicates what processes must be applied to fulfill the design requirements. Conventional and non-conventional machining methods must be applied in many cases where component assembly is required, whereas that which touches the body does not necessarily need the same.
Q: Is machining losing ground in use for medical device manufacturing?
Driggs: The trend for the future might be in that direction somewhat to reduce device manufacturing costs. Until science can produce products that can exactly fit together as a functional bio-structure replacing mother nature’s version, machining of some level is necessary
Q: What common error do design engineers make when specifying for machined parts for medical devices?
Driggs: If design engineers cannot envision the manufacturing processes of a device in an elementary sense, they can design features into a device that are impossible to manufacture (i.e.; right angle holes) or require additional manufacturing steps to produce their designs. The key element here is that a manufacturing review of any design must be performed to optimize factory throughput and minimize cost, prior to going live.
Q: What unique capabilities/functionality do machined components offer to design engineers?
Driggs: Fit, form and function of interconnecting components in a device assembly are best created by the machining of their touching surfaces. Otherwise the predictable life and reliability of the device cannot be proclaimed
Q: For what device sector (besides orthopedic implants) is machining being most often specificed?
Driggs: Surgical tools and associated hardware
Q: Has micro-machining offered “new life” for machined components for medical devices?
Driggs: Yes. Micromachining and the intricate shapes and features required from the macro scale, are a challenge moving forward. The trend is to move toward “nano” in the medical world. There may come a point where conventional machine tools of today will morph into something yet imagined when the time arrives
Q: Where is machining for the medical device industry headed?
Driggs: I predict that by using the cloud combined with MRI and CT scan technologies, there may be a time when medical devices will be partially created to fit the human patient prior to surgery and the final fitting will come next door to the Hospital OR after the surgeon makes his/her incisions. Laser scanning of the body replacement area will be fed directly to an OR CAD operator and delivered to the waiting machine tool. End result is the best ergo fit to the patient instead of machining the patient to fit the device “Medical Star Wars”
Q: Any thoughts/comments on machining or another related area that you would like to share with medical device manufacturers to aid them?
Driggs: Use the 5P principle…Proper-Planning-Prevents-Poor-Performance (defined in terms of fit, function and cost)