The Greening of Medical Product Design

This article was originally published in MDDI on August 2008.

OEMs should know how to make medical device products more sustainable.

The green writing is on the wall: it is time for medical manufacturers to consider the sustainability of their products, packaging, and production processes. In the consumer world, Wal-Mart is undergoing a major effort to adopt sustainability and even hired the ex-head of the Sierra Club as a consultant on this topic. Clorox recently announced its Green Works line of greener household cleaning products. Companies with a strong presence in the medical field like Kimberly-Clark and Philips have long been addressing the problem.

This author’s interviews with medical product consumers around the country have revealed concerns about sustainability. Consumers consistently bring up the topics of global warming or green in discussions about new products that, as recently as two years ago, would have been solely focused on efficacy and usability.

Even if you are not doing something about getting greener, your customers are. Alegent Health, a company with nine hospitals and 8600 employees, has recently named a vice president of sustainability. When faced with a choice of medical products of similar cost and efficacy, it is likely that customers will purchase the greener product, especially if manufacturers have added green to their brand attributes in a way that customers see has real meaning.

Sustainability broadly means considering the environmental effect of a product throughout its life cycle, not just in its creation and initial use. And it is a daunting topic for the uninitiated. Although RoHS and other legislation in Europe have brought some sustainability issues to the forefront, it is understandable that many medical manufacturers have been reluctant to embrace sustainability. The device industry is notoriously slow to make changes. In addition, the industry is sometimes exempted from the legislative restrictions required in the consumer marketplace and is therefore less likely to pursue such change. Further, sustainability has an image of increasing costs.

The good news is that there is a lot of low-hanging sustainability fruit that can be harvested by applying common sense principles and a sustainability-conscious eye to the product life cycle.

This article presents practical advice to designers and manufacturing engineers about how to improve the sustainability of device products. Be prepared to be surprised, as have many in the consumer world—you might just find out that it makes good business sense too.

Start Here: Map the Product Life Cycle

Understanding how manufacturers can use sustainability requires mapping a product’s life cycle. This includes raw material extraction; all processing and manufacturing; actual use; and disposal, reuse, or recycling.

Creating a sustainable product is an attempt to reduce the environmental footprint at each stage with some kind of change. Changes do not have to be massive to have a positive effect. For instance, Philips Healthcare considers a product a Green Flagship if it achieves 10% improvement over its predecessor or competitor. A review of Philips products with such status indicates that most achieved improvements in the 25–35% range.

OEMs usually focus on improving efficacy and usability, and minimizing trauma and cost. Like these factors, sustainability has the biggest influence at a product’s conception. Many sustainable qualities of a product are baked in during the innovation and design stage.

For medical products, the business model is also important. For example, a one-time-use disposable consumes more resources than a reusable product. Of course there may be clinical, product, or sterility issues that require disposability. Because of such factors, the approaches to sustainability from the general consumer or industrial world do not always translate well to medical products.

Quantifying Design Alternatives

Once a specific device’s life cycle is understood, an OEM can begin identifying the places to lower its environmental impact. The team should quantify the effects of various choices.

One way of enumerating a particular design’s effect is to use software such as Life Cycle Assessment (LCA). This software draws on carefully researched databases, allowing manufacturers to estimate the effect of one type of plastic over another, the weight and material type of packaging, or shipping options. Leaders in LCA software are European companies with products such as SimaPro and GaBi.

Although large companies may already own such software or think nothing of purchasing it and training people on how to use it, the software may not be the right place for most device manufacturers to start.

Hans van der Wel, Philips Healthcare’s manager of ecod esign and sustainability, helps run its Green Flagship program. He says the best method for starting out is to “keep it simple. Start with a spreadsheet based on simple indicators. We call ours green focal areas [and] include qualities like the amount of materials, energy, and hazardous substances used.” He says it took Philips 10 years to get to its Green Flagships program.

Example: An RF Surgical Tool

An example product demonstrates how device designers might approach sustainability. A product system includes a disposable and an energy-supplying console. The following section explores the effects of changing these system elements, which are typical to many medical products.

In evaluating the effect of the various components that make up the whole product, designers need to use real impact data. The LCA software makes finding data easy. It is probably the best long-term tool, but it requires a commitment of money and training that might slow initial efforts. Alternatively, the Okala Guide is inexpensive ($12) and has a useful table of impact factors that covers common materials and processes. It is used in this example. The Okala guide combined with a simple spreadsheet may be good tools to get started.

To make this example easy to understand and illustrative of the kinds of improvements possible, not every material or process is compared. In some places, system elements are combined and given overall numbers to ease the reading of the tables.

The analysis focuses on areas in which manufacturers can have the most influence. In practice, when you consider the whole product, the actual impact reduction achieved might be lower than the numbers shown here. However, on an established product, an overall 20–30% reduction is relatively easy to achieve.

Product Description.

A hypothetical radio-frequency (RF) tool for clamping and cauterizing surgical wounds is being considered for redesign. The company hopes to improve sustainability. The product is a system consisting of a disposable handpiece and an RF energy generator and controller.

The Disposable Handpiece: Consists of a plastic-and-metal handle with integrated mechanisms that provide mechanical advantage to the surgeon’s grip during the procedure, and a wiring harness to connect to the console. The handle is currently single-use (all parts) and is contained in sterile packaging. It is manufactured at one location but used in all major global markets.

RF Energy Generator and Controller: Consists of a piece of capital equipment that is a power and control source for the disposable. It is based on five-year old electronics and display technology, has no field-upgradable features, and is intended to last five years. The console is built into its own hospital cart.

Two levels of improvement are considered: first, a few options f or redesign of the disposable, and second, a redesign of the reusable energy-generating console. To begin, readers should understand the existing product’s ecological footprint to accurately compare new design approaches.

Calculating the Footprint.

Everything that is used to make, use, or dispose of a product is scored based on its environmental effect. This is calculated using a rating called impact factor. Impact factor numbers have been gathered or researched and reduced to a standardized unit by an agency such as the makers of LCA software or compiled in resources such as the Okala guide used here. This factor is based on how the particular parameter is used in the product (e.g., per lb material, kWh of energy, tn/miles of transportation, etc.). Totaling the scores yields an overall product rating. In this example, units are in Okala milli points. Impact factor units must be the same for all contributors. Values from sources that do not share units cannot be mingled.

The RF device example looks at the effect for the entire life of the product—about five years. During this time a typical user buys one console and uses 10 disposables per week, yielding a use of 2600 disposables per console lifetime. This means that of the roughly 212,000 impact points, the 2600 disposables used over the product life contribute about 196,000 points. It is important for designers to consider the overall system usage, not just individual parts, in evaluating and comparing the various redesign choices. With this calculation in mind, consider the following possible changes to the hypothetical product.

Scenario 1

Make the Disposable Part Weigh Less (console unaffected). This scenario simply considers using improved design optimization tools such as finite-element analysis (FEA) to reduce the material needed for both the plastic and metal components (without compromising function).

A slight weight reduction has various virtuous effects. Less material is used, which reduces environmental impact. In addition, lower material cost helps offset the increased design and validation costs of a lighter handpiece. Packaging can also get a little lighter to reduce shipping cost and impact.

A modest change to the product, requiring no major changes to the way it is made or used, yields a small but meaningful 6% reduction in impact over the product’s life.

Scenario 2

Make the Disposable Weigh Less and Enable the Wiring Harness to Be Reusable 20 Times. The development team notices that almost half of the disposable’s impact comes from the copper wiring in the leads that connect it to the console. The leads are redesigned to be sterilized and used 20 times instead of just once. The copper content remains the same, but the insulation needs to be beefed up to make the parts rugged enough to withstand reuse. Also, now they will not be packed with every disposable but instead be shipped one set per box of 20 hand pieces. Overall, the product and packaging are lighter, further reducing impact score. A factor must be added for the sterilization by the hospital.

Reusing the wiring harness has a very significant effect. Now the impact is reduced 44% overall from the original product. This redesign does, however, require a change in how the product is sold (box of 20 handpieces with just one wiring harness enclosed) and in how it fits into the hospital’s overall workflow. Hospitals must sterilize, manage, and inventory a wiring harness for 20 uses. But copper is also expensive, so now the cost to provide the function of 20 handpieces has decreased. Such savings could be passed on to users in exchange for the task of sterilization, without negatively affecting the manufacturer’s profit per handpiece. It is a balancing act, because the cost of sterilizing at the hospital may outweigh any savings.

Although the market may not yet be ready to make such a change in how it handles wiring harnesses, the example shows how such a change contributes to making the overall system green. As some large hospital groups become serious about being more sustainable, they may be prepared to make these kinds of changes in the near future.

Scenario 3—Build on Scenario 2 by Redesigning Electronics and Choosing Lighter Materials for the Enclosure.

Now the development team turns its attention to the console and notices that the energy used while the machine is on (usually for a four-hour procedure) affects every disposable. Modern electronics are not only RoHS compliant, but also offer a more efficient package in terms of PCB size. Furthermore, new electronics consume half the energy of older electronics (due to improved sleep modes between uses during the procedure). Now that the console is smaller, it can be built into a lighter, portable enclosure, rather than integrated into a heavy cart. Such changes have a significant effect on both disposable and capital system elements, and yield an overall 52% reduction. Notice that if further changes are made to the console electronics to reduce copper wiring by 20–50% (perhaps by some novel pulsing technique or a change in the frequency of the RF), it would further improve the product’s impact score.

A simple spreadsheet scenario like the tables allows a team to see possibilities for redesign. This is obviously a highly generalized example. Only your technical and marketing teams know where the opportunities lie for your specific product in its clinical efficacy and marketing acceptability.

The Disposable Matters More

In this example, it is assumed that 10 disposables are used per week per console—not an unreasonable assumption for this kind of surgical tool. As noted, this means that over a five-year design life, 2600 disposables are used. Therefore, even a small improvement in the disposable has a magnified effect. By contrast, if the design team halves the impact of the console it hardly reduces the system’s overall impact. Designers must consider the effect of the whole system’s use.

Although the case study shows that focusing the redesign effort on the disposable has the most affect on environment, there are still things the manufacturer can do to the reusable portion of the product that can further reduce its impact. In the example, 50% more efficient electronics in the RF energy generator lowered the energy portion of the product’s impact 2600 times because each use of the disposable cost 50% less energy.

Conclusion

This exercise shows how changes such as lowering energy use through a better sleep mode for the console can have a greener consequence than, say, using a lighter plastic on the enclosure. It’s not always the obvious changes that have the most benefit, and unfortunately, finding the changes that have the greatest potential are not formulaic. Each product will have very different aspects that must be rethought.

Perhaps as an industry we need to reconsider what it means to be green. As Wendy Jedlicka, a sustainable packaging expert, puts it, “The idea that you have to wholly embrace eco like a religion is shortsighted and frankly not sustainable. We need to get everybody doing a little bit of something to mitigate what we are doing right now; then we can keep improving.”

Reference

1. Philips Medical Green Flagships [online] (Amsterdam [cited 28 May, 2008]); available from Internet: www.medical.philips.com/main/company/sustainability/ green_flagships.

 

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