How to design devices for purpose, use and manufacturability

Deepak Prakash, senior director of global marketing and Davy Van Bavel, research and development manager - Europe, both from medical technology company, Vancive Medical Technologies discuss how to design ostomy and wound care devices for purpose, use and manufacturability.

Around the globe, today’s healthcare providers face mounting pressure to deliver optimal outcomes whilst reducing costs. To help these providers achieve these objectives, medical device Original Equipment Manufacturers (OEM) must demonstrate both compelling clinical evidence and a strong value proposition. For manufacturers of ostomy devices and advanced wound care dressings, it’s particularly essential to keep a keen focus on designing for patient comfort, performance and manufacturing efficiency.

Designing for purpose

Designing for purpose is usually at the forefront of device engineers’ minds, and adhesives play an important part. In wound care devices, adhesive materials often must protect the wound, promote healing and absorb varying levels of exudate. In the case of ostomy devices, adhesive materials must protect the skin around the patient’s stoma while securely holding the collection bag.

When designing for purpose, a lot of emphasis is placed on material specifications. The most suitable materials for the physiology of the target patient population are considered, as well as the stability of a material, and if it will be able to remain performing at a suitable standard for the necessary wear time duration. Another factor which must also be considered is if the material will be able to be removed without causing any damage or discomfort to a patient’s skin.

Additionally, there are a couple of adhesive characteristics that can be particularly important to consider when designing for purpose because they affect the patient experience and product cost:

1. Repositionability - if a wound dressing or ostomy flange is made of a repositionable adhesive, then healthcare providers and patients may not have to dispose of the device if they are not able to affix it properly on first attempt.
2. Moisture management - materials that offer high breathability and/or fluid absorption can extend wear time, therefore reducing the frequency of dressing changes. Transparent adhesive materials also can minimise how often providers or patients must lift or replace a dressing to evaluate the wound bed, saving the expense of buying more dressings and alleviating some stress for the patient.

Adhesive medical materials can be designed to offer varying levels of moisture management. For example, an ileostomy appliance must be able to manage more liquid output than a colostomy appliance. A wound with moderate exudate requires a different dressing than one that is producing very high exudate. An experienced materials supplier will be able to recommend the best adhesive for the use case.

In ostomy devices, wear time also is affected by how well the skin-contact adhesive material can protect the healthy skin around the stoma area and keep it from deteriorating. In some cases, the patient’s skin may be damaged around the stoma, and the adhesive material must help promote healing. New hydrocolloids with additives might be a good choice in either circumstance. Examples of additives include essential oils, vitamins, antimicrobials, odour absorbers, topical pain relievers and moisturisers.

Designing for use

The purpose of a device is one thing, but whether a patient will actually use it as prescribed can be quite another. For ostomy and wound care products, in particular, device engineers can work with material providers and other supply chain partners to master the art of wearability. A number of human factors come into play such as if the device’s form factor is suitable for the patient’s lifestyle and if the device will fit comfortably under the patient’s clothing. Other factors that are considered are if the device can manage perspiration and other fluids from daily activities such as exercising and showering, as well as freedom of movement.

Yet again, the right adhesive materials can support a number of usability objectives. Rigorous adhesive biocompatibility testing helps to ensure the device will not irritate the skin or cause an allergic reaction. Adhesive materials that are stretchable and conformable contribute to patient mobility, helping individuals to go about their daily lives as freely as possible, without having to worry about dislodging their device or disturbing their wound. A material can be engineered to allow moisture on the skin to evaporate through the device while keeping fluids from the outside world from entering.

In ostomy care, discretion is one of the most important quality of life considerations. An adhesive material supplier with ostomy expertise can recommend flange carrier materials with odour-absorbing properties. Flanges are typically made of thick, mouldable hydrocolloids and conformable foams, films and soft nonwovens. Ostomy bag materials also can be odour-absorbent and engineered to be quiet so that they don’t rustle when the patient moves. Suitable materials can help ensure that the ostomy appliance design has a smooth, non-obtrusive profile under clothing.

Designing for manufacturability

Designing for purpose and use are incredibly important; the device must perform, and the patient must be comfortable wearing the device. Designing for manufacturability is another realm where an experienced adhesive material supplier can help the OEM to save cost and improve performance. For example, a supplier may be able to identify two materials that can be combined to accomplish what previously took three or four different materials. A supplier may also be able to recommend thinner, lighter-weight adhesive materials that will both conserve cost and be more comfortable for the patient.

Manufacturability relates to selection of not only adhesive materials but also complementary release liners. The adhesive and liner combination, each with its own specific release formulation, contributes to smooth material processing on roll-to-roll manufacturing lines. The release liner also helps support adhesive materials during die cutting, ultrasonic welding, sterilisation and other production processes. For ostomy devices, these materials are often weldable, single-coated nonwovens, films and foams.

Conclusion

Ostomy and wound care device design is a multifaceted, multidisciplinary endeavour requiring a balanced approach to performance, cost and comfort. As foundational building blocks of these devices, adhesive materials play a significant role in determining how a device performs, how the patient feels about using it and how efficiently it can be manufactured. For successful device design, there is much to be gained from collaboration between supply chain partners, including materials suppliers, OEM designers, converters, equipment manufacturers and healthcare providers.