Originally Published MDDI October 2001
Originally Published MDDI October 2001
Using Computer-Aided Design to Enhance Product Development
More than a design tool, CAD can improve communication, help control the design process, and reduce time to market.
|Computer-aided designs, such as this model of a fingertip-sized heart pump, can reduce the number of physical prototypes that must be made.|
Computer-aided design (CAD) is a tool intended to facilitate the evolution of a complex set of concepts into a completed product. Like all tools, CAD is an extension of the user, reflecting that individual's skills and experience. Within the span of a few decades, the use of pencils, pens, and paper has given way to computers and software. Use of CAD has become commonplace in the high-tech industries. But the transition has not been without its pitfalls.
A former tool designer in the aircraft and aerospace industries likes to share the story of his company's shift to CAD. When the decision was made to fully embrace the new technology, the firm's engineers, drafting personnel, and designers were offered lucrative early retirement options to make room for the new CAD team. But within two years, a large number of these retirees were offered equally generous fees to act as consultants. "The company wanted us to come back and give refresher courses in basic drafting and design," he explained. The new CAD tools enabled the designers to render beautiful drawings at a rapid pace. "But," he added, "the new team kept designing things that, in this world, were impossible to machine or build. So they needed help with using the basic tools and concepts."
This critical relationship between a tool and its user is echoed by Bruce Christie of I.N. Inc. (Los Alamitos, CA), "Did the word processor make everyone an author? Did the Paint program make everyone an artist? No. [CAD does] make you a more productive engineer and it makes you able to tackle programs that perhaps you couldn't tackle with your pencil and paper. But whether you get the job done right, and if the quality of the result is acceptable to the client, depends on the quality of the engineer who's doing it."
Rex O. Bare, president of product development firm Omnica Corp. (Irvine, CA), agrees. He contends that "if the person using the tool doesn't know what he or she is doing in the design process, the tool won't make the design better. It might make it look more interesting, or a little more presentable, but it still goes back to the competency of the person using the tool."
CAD offers diverse benefits in the design process. Among these are more-effective communication, greater control over the design process, and savings in development time. Each of these are factors in achieving an improved flow of ideas from initial concepts through design processes to the finished product. Use of CAD tools also allows a broader range of design factors to be considered.
Product success is influenced significantly by the level and extent of communication achieved during the development process. CAD software is being used to help create an environment in which each participant can make effective contributions to this process. In addition to designers, participants can include experts in human factors and other specialties, as well as representatives from management, marketing, and manufacturing.
Bare explains that the use of CAD "encourages the participation of people who might not normally have been able to make meaningful contributions based on looking at drawings. The marketing guys, the managers, the people who would not have been interested in or been able to deal at the level of an engineering drawing can absolutely look at full-color, fully shaded images and understand what they're looking at. So they can participate, and they do."
From the design consultant's view, the level of communication allowed by CAD systems also addresses another problem. Says Earl Robinson, vice president of industrial design at Omnica, "The 'not invented here' syndrome is real. There are territorial problems. We're consultants, and when we go into companies to work for them, quite often people feel threatened."
Robinson believes that such attitudes can be addressed effectively through broader participation in the design process. "When you can do this as a team, and you get the sense of authorship from everybody at the table, and everybody can give their two cents worth, then it moves a lot faster. We get consensus quicker using CAD. Period."
The current generation of CAD systems also provides a degree of functionality that can enhance the communication of complex concepts. Says Bare, "By being able to look at all sides of the thing, with the section views, with the fit, we're able to solve a lot more of the problems and look at more potential solutions or approaches than we could ever do with the older kinds of systems. And once you have that information in a CAD form you come to realize that there are so many things you can do with itanimations, photorealistic renderings, educational arrows pointing to features to communicate with marketing people or customers, or putting that information into reports so that somebody reading the report knows what they're looking at. You are able to go through all of those things faster, better, and with better communication."
Another advantage of involving more key individuals in the early phases of the design process is that it helps to increase understanding. Says Bare, "One of the reasons it used to be so hard to get consensus was that people weren't willing to commit unless they understood. And they weren't willing to admit they didn't understand, so they dragged their feet so it wouldn't be obvious they weren't understanding what they were looking at. Here that's really not an issue. They may not like what they see or they may react to it and tell you what they don't like or whatever, but at least they understand what they're looking at. And that's fundamental because it's all about communication."
Echoing this idea about communication, Robinson says, "Most of the time what we find is that if you ask the customers or the marketing guys what they want, they really can't tell you very well. But if you show them something and ask them if they like it, they can tell you that."
Ron Sully, Omnica product development, says, "I was talking with our head designer the other day about drawing and his drawing skills, and he said 'These days a lot of times I'll model something because I literally can't draw it.'" Bare adds, "CAD helps designers visualize things. A lot of times it's difficult to visualize something well enough to talk about it. You can kind of begin to visualize this thing and you can talk about it in the abstract, but you couldn't yet draw a picture of it. But if your part's going to be cylindrical and it's going to have some notches here, you can create that in a solid image and then you've got it. You know where you go from there. So the tool itself can help pull you through some design hurdles that would have been really difficult to figure out how to illustrate with the old line drawings."
CAD tools also allow larger teams to tackle design challenges. Says Christie, "The 3-D CAD systems allow a greater degree of collaboration. You can assign multiple engineers; at one point we had as many as four people working on various parts of one product, all working in parallel and knowing that they're not going to get into problems because the CAD system helps enforce the interfaces between the individual parts and keeps everything fitting. So what that did is this. [Although CAD didn't] have as much benefit in reducing the total number of engineer hours, it had a tremendous benefit in reducing the number of weeks to completion."
CONTROLLING THE DESIGN PROCESS
When I.N. Inc. designers worked with Masimo Corp. (Irvine, CA) to develop the Radical SET pulse oximeter, a gold-medal-winning entry in the 2001 Medical Design Excellence Awards (MDEA) program, CAD was an essential part of the product development process. "I think it was crucial," says Christie. "And the reason is that Masimo was anxious to get the product to market, and it was a fairly complicated product. If you look at the parts breakdown, it's a fairly complicated, involved product, with a lot of functional characteristics. It has a lot of interfaces between parts because of the fact that it has a separate desktop and handheld parts that snap together, with a swivel connector on it. And all these functional aspects are things where computer modeling certainly helps you get to a functional design much faster."
He adds that Masimo was concerned that the device have an attractive yet professional appearance. "The ability to use CAD to implement the industrial design of that product was a critical factor," he says. "Without a high-end CAD tool, it would have been very difficult to achieve the appearance that we accomplished on that. So for both functional and appearance reasons, CAD was very important."
I.N. Inc. sales and marketing manager Jeff Herbert adds, "A lot of the sexiness in the overall appearance of the design was driven by the industrial designer in trying to get an ergonomic feel on the product. We're talking about a handheld product that snaps into a base and charging station. So the ergonomics, the human factors needs, drove a lot of the overall design and then had to be captured with the sophisticated CAD tool that we used."
Omnica also contributed to the development of an MDEA-award-winning productthe HELiOS personal oxygen system from Tyco Healthcare Puritan-Bennett (Indianapolis). Use of Solid Works CAD software enabled Omnica's team to consider a large number of possible solutions and examine many design details, says Bare.
Commenting on this aspect of CAD, Robinson adds, "You can look at so many more details earlier on that are options. You would only consider a few of those options perhaps in years past, where now you can look at 15 or 20 possible approaches and you can mix and match features and carry along a lot more of these options through the design process, without them slowing it down or adding so much complexity that you can't carry them along." Robinson warns, however, "Sometimes that's good and sometimes it's bad. It can lead to what we call creeping elegance, which is 'while we're at it, let's throw in this feature' and nobody asked for it or wanted it. And you have to fight that tendency."
A recent example of how the use of CAD can significantly shorten the time needed to develop new products is the Cardionove implantable heart pump (see sidebar). According to Cardionove Inc. CEO Conrad Pelletier, the use of CATIA software from IBM significantly shortened the product's development time by reducing the number of physical prototypes that were needed.
Pelletier explains that the software allowed the designers to rely more heavily on modeling than on creating prototypes. He says,"It's easier on a computer model to modify any one of the parameters that you believe will improve the design, and you can see the results immediately without actually having to cut the prototype itselfwhich is a lengthy procedure. Just to machine the prototype is a matter of almost a month. Then when you study the prototype on the bench, it's another two or three weeks before you have results. So if you can model these results on a computer, it's so much faster. Within the same length of time you can develop two to three prototypes rather than only one."
He adds that the software was also used to analyze how the device would interact with human blood. He explains, "We've also worked on trying to predict the zone of hemolysis, which was a surprise to us as a possibility. So on the computer model we could look for areas of nonlinear flow, which is where the destruction of red blood cells occurs mainly. We could then modify the design of the prototypes so as to keep hemolysis, the destruction of red blood cells, to a minimum. This was also a discovery that we made after we started using the models."
The software also provided several key advantages in transferring the device design to actual production. Rishi Madabusi, business development manager for IBM Lifecycle Management, adds, "One was being able to take the virtual model and create the kind of manufacturing instructions needed to create physical prototypes if you wanted."
Madabusi adds, "We're getting to places we couldn't otherwise. And doing it more thoroughly and looking at more options. We might have been able to get one or two solutions carried through with the older methods and arrive at something like the same point, but we're going to get there with a lot more thorough treatment and a better understanding of more things about the product when we get there. It may still have taken us six months to work our way through the mental process to get there, but six months out, with the CAD system, we're going to have looked at it much, much more thoroughly than with older systems." He adds, "In that sense it absolutely shortens the time that we're taking to look at all those options. But there is kind of a minimal time involved with any concept, from the early stages to where it's beginning to be a real workable product. I don't know that we've shortened that by too much."
The use of CAD systems has evolved substantially since it required aerospace designers to emerge from retirement. It now enables engineers and designers to explore many possibilities before bringing solid ideas to the table, to interact more effectively with key departments and individuals at earlier stages of development, and to make better use of time and manpower during critical phases of product development.
|CAD software enables designers to better visualize concepts.|
These are the key advantages now being offered by CAD: more-effective communication in setting design parameters, the ability to exercise a greater degree of control over the process, and more rapid development time. Of course medical manufacturing is not the aerospace industry. Robinson explains, "The medical industry isn't built on urgency. It's built on thoroughness and quality and thought processes. There are other industries, like automotive and the movie industry, where things are totally built on deadlines. The medical industry isn't built that way. It's more about doing it right. And I think there have been instances where we have done things in time periods that would have been impossible without CAD because we did figure out all the problems early. We solved the fits, we took all the spec sheets off the Internet for the internal components, and when it was built, it was right. We nailed it the first time around. It's not what you do commonly, but it can happen."
Copyright ©2001 Medical Device & Diagnostic Industry