Whipsaw

Keeping the Patient in Mind Leads to Outstanding Design

By: Erik Swain

Manufacturers who considered a patient’s comfort level lead the pack in the MDEAs.

Vital Heat Body Temperature Regulator

The Vital Heat body temperature regulator is a small, portable, easy-to-use means of allowing patients to recover their body heat after surgery. Unlike alternative products, which require a patient’s entire body to be covered, the Vital Heat works by simply placing the patient’s hand into a chamber. The manufacturer is Dynatherm Medical Inc. (Burlingame, CA).

“Patients in postsurgical intervention who are unable to thermoregulate their temperature stand to benefit from the use of this device,” says juror Yadin B. David, director of biomedical engineering and television services for Texas Children’s Hospital (Houston). “It is based on a combination of innovative technology and simplicity of application. Caregivers need to treat and examine the patient’s surgical-site wounds, and in doing so, they have to remove the warm blanket. This compromises the patient’s core temperature. However, with this device, the need to place warming blankets on top of the patient may be eliminated, allowing caregivers increased ability to access patient wounds.”

The hand is placed into the chamber, sealed, and attached to a paddle unit. A PVC film provides a barrier between the hand and the paddle, keeping the hand chamber sterile. A low-wattage pump moves 43°C water through an aluminum heat sink under the chamber. A 1-psi vacuum in the chamber makes the hand’s blood vessels dilate, enabling warmed blood to be returned to the body core. Normal body temperature can be restored as quickly as six times faster than with any other noninvasive technique.

Dennis Grahn is a researcher in Stanford University’s department of biological sciences. He discovered in 1998 that the capillary bed in the palm of the hand could quickly transfer large amounts of heat to the body core. He also found that pulling a vacuum tricked the blood vessels into dilating. Grahn patented the technology and licensed it to Dynatherm, which enlisted Whipsaw Inc. (San Jose) to help design a device. “It was a long, iterative process,” says Tom Keegan, director of marketing at Whipsaw. “We did more than 200 mock-ups and tried them on lots of patients, who had to be observed the entire time.”

The chamber, which is completely transparent so blood circulation in the hand can always be monitored, is designed to accommodate a wide range of hand sizes. Even if left unattended, the device will turn off automatically and never allow the water to be heated over 43°C.