The Value of Concurrent Design and DFM for Medical Devices

The final interview in our MPR series is with Leon Marucchi, Director of Industrial Design and Katie McHugh, a design engineer at the international consulting firm. Below they discuss concurrent design and design from manufacture and the tremendous value it provides in bringing a device to market.



Click below to hear full audio interview and see transcript that follows.

Brett Johnson:           Welcome from New York, Brett Johnson with OneMedRadio. Today, we are with Leon Marucchi who is the director of industrial design and Katie McHugh who is a design engineer at the international consulting firm of MPR Associates as part of our expert series on compressing the time to bring in new medical device to market. MPR has been in this business since the late ‘60s and have brought numerous devices to market. Today, we’re talking about concurrent design and DFM or design from manufacture and the value that it can provide in accelerating this process. Thanks for joining us today.

Leon Marucchi:     Good to be here, Brett.

BJ:          So Katie, why don’t we start with you? What is concurrent design exactly and what are its advantages?

Katie McHugh:           Well, in a concurrent design process, you bring together a team that has different skills in different areas. So you’re working with people who have skills in creative design and design engineering and also in manufacturing and assembly so they can work together to make sure that each of these areas are considered from the beginning so that you can anticipate problems and resolve those earlier in the design process.

BJ:         What is the difference between what an industrial designer does and what a design engineer does?

LM:     Well the difference is, the industrial designers really focus on the user’s needs. We really need to investigate and talk to the key opinion leaders in the industry and learn exactly how a specific instrument or device is going to be used out in the field. Because we don’t understand where we’re going to go with our design unless we know how they’re going to be holding this, what are the ergonomics, you know, what is the balance of weighting of the tool.

And on the engineering side, we’re concerned about minimizing the assembly, minimizing the complexity of the assembly to get the job done and keep it within an envelope that the industrial design is correct for the user in their environment.

BJ:    Interesting. So, in terms of how this process works, you talked about sort of a real time communication, what does that mean?

KM:     So on a daily basis, I’m a design engineer and Leon is an industrial designer, we’re talking several times a day when we’re together on a product. We’re looking at issues that come up with the parts and we’re figuring out ways that we can resolve the issues that will be satisfactory both from the user’s perspective and also for the detailed design of the device. So it really means having constant communication with these groups within one organization.

BJ:   So, how does this differ in terms of the development process from a traditional kind of approach?

LM:     Well the linear and the parallel approach are two simple words and ways to look this. So working in a parallel approach again, we’re working these solutions together. We’re not working on top of each other but we’re working concurrently to resolve issues as they come to play in real time. In a linear approach, the job, the tasks and the solutions come from individual disciplines in separate areas at separate times. So as an industrial designer, I may say, boy, does this look good and this is the position I want a hand to hold this specific instrument in the operating room environment. But I’m not considering the constraints that come to play for the engineer to actually allow the volume to be a small as I want it, the weight to be as light as I need it. I need the inputs real time concurrently from engineering to make that happen. A parallel process allows that and a linear process we end up with disagreements and we have to go back and revisit solutions instead of keeping things flowing towards manufacturing.

KM:    Right. So you really end up with sort of a struggle at each step if you’re trying to implement a linear process. Because as a design engineer, I might get input from the industrial designer and take a look at putting in the details into the design and figure out that well I can’t do what the industrial designer is asking me to do in the detailed design. So just talking about that upfront, it avoids a lot of frustration and a lot of iteration, which really adds to the ultimate timeline of the product.

BJ:    Interesting. You talk about a user-centered approach. How does a user-centered approach relate to concurrent design process?

LM:   Well the user again, you know, he’s the end user. He’s the one that needs to be accommodated as well as possible with our design and with our output from production. So this approach, the user himself with the details that we instill and we put within this device, the only way we can make that real is again to have not just industrial design mechanical engineering, embedded systems, and production issues on the table at the beginning of our project plan. We have to know how the user is going to use it, center our efforts in all these areas on how to best accomplish that. We can’t come to a manufacturer and say here’s the design at the end of the road because he’ll come back to us and say well we can’t mold that.

BJ:    Interesting. So I guess that’s the whole idea of DFM or design from manufacture?

KM:   So in design from manufacture, you need to consider the final fabrication process and you also need to consider the final assembly process. You want to minimize the number of parts, you want to make assembly as easy and simple as possible, and you want to really optimize your individual part design for the technique that you’re going to fabricate the part from. So as Leon mentioned, if you’re going to have an injection molded part, you’ve got to be talking to the injection molding vendor that you’re considering early on to get their input. You need to be considering good design practices for fabricating the part in that way and that will really make your timeline shorter as opposed to if you do not consider that and then sort of threw it over the fence to the fabricator in the end and found out that you had a lot of problems.

BJ:    Do you have any examples in the past in what you consider good DFM and how it leads to higher quality and lower cost?

LM:   Sure. So if you’re asking about when we instill design from manufacturing and are worried more about cost or quality, there’s a balance here. There’s a requirement specification that lives with us and grows throughout the project from beginning to end. These are the things that must be instilled with the product design itself. Some of those can even be user requirements. They can be weight associated, they can be the angle of the display. These are given. You must resolve these issues.

Now you want to minimize — as Katie had said, you’ve got to minimize your overall assembly, the complexity of that assembly, how many screws are involved to put this assembly together and how many parts and how many tools, what the capital expenditure to make this design happen. So we’re always concerned with that flow of complexity to resolve these solutions, giving it the right aesthetic appeal, give it the right ergonomics but at the same time at the end how much is this going to cost.

This is part of our project plan upfront. Our customers don’t know come at the end of the project and find out that the tooling expenditure or the unit cost for this device is twice what they expected because we instill this at the beginning of our project. We figure out the balance of quality. Well quality is always high but we figure out the balance of aesthetic quality and of the production costs that are involved to make this thing happen.

KM:    Right, so that’s a good point. I’ll give you an example of a recent project that Leon and I worked on together where some of our design decisions were driven by the ultimate cost to manufacture the parts. We were working on an assembly together where we had a mechanical structure inside of some enclosures and the enclosure is obviously very important, the aesthetic look of the enclosures is obviously very important. We were looking at early build of materials and the cost to fabricate some of the custom elements of that assembly.

At that time, we looked into different fabrication options and were able to incorporate into the design early on some aluminum die-cast components that combined individual machined components and overall reduce the cost of the final product. If we had waited until we were ready to launch in manufacturing to make that conversion to die-cast components, we would have been doing a lot of rework to figure out how to incorporate the die-cast elements into the mechanical assembly. So that’s just an example of a choice you can make early on in the design that can make things a lot easier for you down the road to help reduce the cost of the products.

BJ:  Well it sounds like design can have a dramatic impact on the ultimate cost of a device.

KM:    It certainly can. The choices that you make early on about what type of fabrication processes to use and how to design your mounting surfaces even within your parts is very important. So if you’re using a die-cast part for example, can you create geometries so that you can use an as-cast geometry instead of having to have secondary machining because your features are not in the correct direction for the mold. Just considering how you’re mounting things to minimize that additional machining or for injection molded parts for minimizing side actions can save you a lot of money down the line. You just have to be thinking about that upfront in your design.

BJ:   Interesting. So are there any general global perspectives or global advice you’d give to let’s say a company, a new venture and they’ve got an idea for a device, you know, sort of the big picture on what they should be thinking about and the philosophy they should use as they approach this process?

LM:     Well, Brett, it’s definitely to be user centered. You know, in the end the customer has to be happy with this product. So if you’re not basing your plan and your approach to resolve and develop this design on the user needs and if you don’t fully understand what they are and the complexity of those needs, if you don’t bring those in to play at the beginning, then you have quick fixes that have to happen during your evaluations. Because step by step you’ll evaluate your development process with users and if they come back to you and you haven’t considered their main needs, then you’re going to find yourself in a lost circle here and spending a lot of time and money that is unnecessary to get this done.

BJ:      That sounds like great advice. Well thank you guys. It’s a terrific insight on the process of bringing a device to market. It sounds like you’ve got some good insights on how to accelerate it and do it in an intelligent fashion. So thanks for joining us today.

LM:    Brett, thank you very much for your time.

KM:    All right. Thank you.

BJ:    So that is Leon Marucchi and Katie McHugh with the international design firm MPR Associates, which has been specializing in the medical device area for many, many years. Thanks for joining us today guys. Thank you all for our listeners. Brett Johnson from OneMedRadio in New York signing off. Good day.

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