An MD&DI September 1998 Column
Animation helps elicit more feedback during the design phase of product development, saving both time and money down the road.
The length of time involved in development has been shown to have the biggest effect on a product's profitability over its life cycle. The actual cost of manufacturing the product has the second biggest effect. During the past few years, much has been written about how concurrent engineering and rapid prototyping can accelerate product development. However, these tools have not been as effective in reducing the cost of manufacturing.
Computer animation is a little-used design tool that has significant potential for both accelerating product development and reducing the cost of manufacturing. Animation delivers megabytes of information in seconds, in an accessible and appealing manner that can stimulate the active involvement of the entire project team throughout the product development cycle. Animation can help elicit the participation necessary for concurrent engineering and the input needed to capitalize on rapid prototyping.
THE PRODUCT DEVELOPMENT CYCLE
During product development, input is required from a project team representing a range of interests within the company, including program management, marketing, hardware and software engineering, manufacturing and procurement (operations), quality control, customer support, and finance. Under the concurrent engineering approach, all team members should participate actively throughout the development cycle and especially during the design phase. Unfortunately, participation often drops off once the physical product specifications have been established.
In the past, prototypes were all too often created by design engineers in what was essentially a vacuum. Drawings and specifications were developed from the prototype, and the design was simply passed on to the production department with little concern for the product's manufacturability. Often, when this occurred, the device could not be manufactured consistently and reliably. Prior to passage of the Current Good Manufacturing Practice Quality System Regulation (21 CFR 820.30) in 1996, design failures of medical devices were estimated to have been responsible for as many as 60 deaths each year and 44% of device recalls.1 One of the primary reasons FDA initiated design control in the new rule was to diffuse design responsibility throughout the organization and ensure shared decision making.
Design control requires input up front and continuing involvement from the project team. Design engineers receive input from the preconcept and concept phases and create an initial on-screen prototype using computer-aided design (CAD) and solid-modeling techniques. They must then receive the project team's feedback on their initial design. Does the design meet product specifications? What trade-offs will marketing be willing to make in the interests of controlling cost? What potential problems does customer service anticipate from the design? Is the design practical from a manufacturing standpoint? The entire team must work together to identify any problems early in the design phase to avoid delays later in development and to ensure a reliable, high-quality medical device.
TRADITIONAL PRESENTATION OF DESIGN
Design engineers often have problems getting the input they need from the rest of the development team. In most cases, the primary reason is that team members lack the time required to understand the design. Yet without a thorough understanding of how the designer plans to assemble, test, and service the product, they cannot provide constructive feedback.
The traditional means by which design engineers communicate their ideas—sketches, drawings, and blueprints—are static, two-dimensional media that are not particularly appealing and require a certain amount of interpretation. CAD and solid-modeling tools are highly visual and interactive, but these programs require powerful and expensive workstations such as Sun, Silicon Graphics, or high-end Windows NT systems that are usually not available outside the design office. Thus, design engineers are still often faced with presenting output from these sophisticated, interactive tools in the form of static, two-dimensional printouts.
Of course, CAD tools can be combined with rapid prototyping techniques to produce physical prototypes. However, physical prototypes are far more expensive than software prototypes. It is less costly for design engineers to complete most of their design iterations and initial testing using computer-based solid modeling. In addition, with finite element analysis, properties of the assigned materials can be added to computer models, making virtual testing more realistic than tests run on physical prototypes, which often are not made from the same materials as the final product.
What design engineers need is a way to communicate product design information easily, actively, and inexpensively with all members of the development team. This option is provided by applications that can translate workstation CAD files to desktop personal-computer files and, better still, to PC-accessible, computer-animated video files. CAD files are typically in IGES (initial graphics exchange specification), a graphics file format for three-dimensional wire-frame models. Design-tool animation software can convert IGES files into AVI (audio/visual interleave) files, which can be used to create fully rendered animations.
For example, CAD platforms such as Pro/Engineer from Parametric Technology Corp. (Waltham, MA) allow the designer to save files in the stereolithography (STL) format and then import them into animation software. The designer must then create the animated video, taking into account issues such as lighting, the sequence of moving parts, the path each part travels along, and so forth. The key issue, of course, is information transmission, not creating a movie-quality video. Animation applications available to designers include SolidTools from Visionary Design Systems (Santa Clara, CA), dVISE from Division (San Mateo, CA), and IPA from Immersive Design (Acton, MA).
Using such software, engineers can translate their designs into computer-animated videos for presentation during design reviews. Video eliminates the need for special skills in reading blueprints or interpreting two-dimensional designs. In addition, animation stimulates concentration and draws the audience in: viewers become involved in an object's motion and anticipate its next move.
Animation can also give an audience a gut feel for the product that static drawings most often cannot provide. There is a human tendency to postpone worrying about something until it is real, which is why so many changes are made to a product late in the development cycle when a physical model is finally available. Computer animation lends a sense of concrete reality to a product, increasing the likelihood that required changes will be made earlier, during the design phase. This can reduce the overall product development cycle, enhancing the product's profitability.
An additional and not inconsiderable advantage to animation is that far more information can be delivered in a shorter time using video than with two-dimensional images. Gigabytes of information can be presented in a five-minute animated video, quickly bringing an entire product development team up to speed and freeing valuable time for analysis, discussion, and, if necessary, problem solving.
The videos created by animation software can often be imported into programs such as Microsoft Office, Lotus SmartSuite, and Corel PerfectOffice. Some can also be transmitted as Adobe Acrobat files that can be read or viewed using any computer platform. Both AVI and Acrobat files can be transmitted by E-mail, so that videos can be sent out in advance of a design control meeting. The files can remain on the team members' desktop computers for reference after the meeting and can be forwarded to anyone who needs to be consulted later.
The ability to transmit animated videos by E-mail can also eliminate some face-to-face meetings. This can be especially useful when working with independent design firms and contract manufacturing companies. Even medical device companies that have their own design and manufacturing capabilities do not necessarily have them both at the same location. Having animated videos makes it convenient to involve one or more contract manufacturers early in the design stage. Videos can also help overcome language barriers with foreign manufacturers by facilitating interpretation of written specifications or drawings.
Finally, video is an excellent tool for communicating with individuals outside the development team. It can be used to obtain early input from customer focus groups and to keep investors or members of the board of directors informed about progress toward a completed medical device. Even well beyond the design stage, animated videos can serve as training tools for assembling or servicing a product. Individual parts can be seen moving into place, not just from one angle, but from many angles, and no long-winded explanation or hand waving is required to convince viewers that the design will be easy to assemble.
Adding animation to solid modeling and analysis helps design engineers realize the full potential of their tools. Computer animation saves time—quickly capturing viewer attention and reducing the amount of time required to convey information. A computer-animation video can present gigabytes of information in minutes using a form anyone can understand, regardless of occupation or nationality. By improving development team participation, animation can also enhance productivity, resulting in higher quality, lower costs, and earlier product introduction.
1. "Medical Devices; Current Good Manufacturing Practice (CGMP) Final Rule; Quality System Regulation," Federal Register, 61 FR:52602-52662, October 7, 1996.
Robert L. Lathrop, Jr., is president of Lathrop Engineering Inc. (San Jose).
Among the animation applications available on the market are the three that are mentioned in this article: