In-home medical devices must be safe, lightweight and easy to use.
Medical device engineers must consider the needs of both health care professionals and patients when designing products for in-home applications. Sometimes, those needs conflict with each other.
“Physicians and nurses want equipment that is easy for the patient to understand and use,” says Amy Korn-Reavis, coordinator of A.W.A.K.E.Orlando, a support group for people with sleep disorders. “This reduces the issues with nonuse and complications. Some physicians also like online monitoring so they are able to review a patient earlier in the initial use period to see if they are doing well and can solve problems sooner.
“Patients want equipment that is easy to understand, small and aesthetically pleasing,” adds Korn-Reavis, who has been a respiratory therapist for the last 25 years and has seen a lot of changes in the way that in-home devices are designed. “They also want the equipment to be as comfortable as possible.”
“Traditionally, medical devices are complex products that are used by highly trained professionals,” says Len Czuba, president of Czuba Enterprises Inc., a medical device design firm. “With in-home products, engineers must rethink who is using the devices.
“Any device used in a home setting must be foolproof so that any person can easily understand how it works,” warns Czuba. “Older patients often have poor eyesight and their ability to move may be limited. Arthritis often restricts hand strength and tactile coordination.” Other limitations include reduced physical strength, stamina and hearing.
“Continuous positive airway pressure (CPAP) machines [which are used to treat sleep apnea] are now quieter and have algorithms that help match breathing patterns more closely,” Korn-Reavis points out. “The machines are also much nicer looking today. One of the new ones has a built-in alarm clock. Another looks similar to books sitting on a night stand. The masks [that are attached to] the machines are becoming more user-friendly, as well.”
Increasingly, people with chronic illnesses travel for business and take vacations. “People don’t want the device to be debilitating,” says Czuba. “They want to maintain active lifestyles and take their medical devices along on cruises.”
As a result, medical device engineers are focusing more attention on the mobility of at-home devices to ensure that they can go where and when patients want to. For instance, oxygen concentrators have gone mobile.
“The small, portable concentrators allow people to travel easier because they are able to be plugged in when the person reaches their destination,” says Korn-Reavis. “It helps to eliminate bringing multiple oxygen canisters when they travel.”
A good example is the EverGo concentrator from Philips Respironics. It weighs less than 10 pounds and features an 8-hour battery. It is even federally approved for in-flight use on commercial airlines.
Because in-home medical devices need to be portable yet robust, plastic is widely used for housings and bodies. “Devices need to be lightweight so patients-particularly the elderly, ill or disabled-or their caregivers can lift, move and operate them without assistance,” says Tom O’Brien, health care product marketing manager at SABIC Innovative Plastics. “Plastics can significantly reduce weight and mass when used as replacements for metal and other traditional materials.
“With the expansion of home health care, [engineers] are focusing on greater ergonomics and aesthetics to make devices comfortable and attractive for consumers,” O’Brien points out. “An attractive appearance makes it less intrusive in the home setting. End users want devices that resemble pieces of furniture and look good in a living room or bedroom.
“The ability to mold complex shapes and to consolidate parts are important in creating eye-catching ergonomic designs,” adds O’Brien. Unlike other materials, plastics can be colored and given different surface textures and finishes that blend with home furnishings.
Hospitals are not as concerned with aesthetics. “They also have rigid cleaning and sterilization processes, but that’s often not the case with home health care,” says O’Brien. “Ease of maintenance is important when designing new products. Plastics are easy to keep clean and are resistant to common household cleansers.”
“Many antimicrobial materials are being offered, which lend themselves to in-home medical devices,” adds Czuba, who is past president of the Society of Plastics Engineers. “Contamination and sterility are big concerns as more devices go home with patients. Anything that can help eliminate surface bacteria is worth considering.”
Most of the plastic components used to assemble in-home medical devices are bonded together. “Ultraviolet, light-curable adhesives are popular with manufacturers, because they offer speed and economy,” note Kyle Rhodes, medical market segment manager at Dymax Corp. “We see a lot of acrylics and polycarbonates used for plastic housings.”
According to O’Brien, polycarbonates are ideal for in-home devices because they offer impact durability and high flow for thin-wall molding, in addition to optical clarity. The material is also ideal for ultrasonic welding applications.
“One of the most promising areas is the evolution of plastic compounds,” says O’Brien. “Compounds can deliver exceptionally high performance, including mechanical strength, lubricity, wear resistance and dimensional stability to facilitate tight tolerances for device specifications.”
To learn more about in-home medical device trends, click www.assemblymag.com and search for these articles: