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Stanford Report, July 24, 2002

Henk Vreman and his custom-made phototherapy beds step out of the lab and into the spotlight


Franco Bernardo had a problem. His hockey team had made the playoffs, but the 13-year-old Canadian's participation would stop when his team hit the road. Severe, life-threatening jaundice requires Franco to sleep on a bed under fluorescent lights -- all night, every night. It was out of the question to move the bulky phototherapy bed to Montreal, the site of the competition.

That's when Franco's mom contacted Henk J. Vreman, PhD, senior research scientist in the Department of Pediatrics. Although Vreman is a biochemist studying the metabolism of hemoglobin to bilirubin -- a naturally occurring compound that gives jaundiced patients their characteristic yellowish hue -- Maria Bernardo was more interested in his other specialty: designing portable phototherapy beds for kids like Franco. After hearing of Franco's dilemma, Vreman custom-made and hand-delivered a bed for him, ensuring Franco could play in the tournament.
Henk Vreman studies light emitting diodes, or LEDs, as a way to reduce bilirubin levels in children with jaundice. He is working to design a portable, high-efficiency LED-based phototherapy bed for children with severe, life-threatening jaundice. The beds will enable these children to have more freedom.

"I've dedicated part of my life to helping these families with whatever it takes," said Vreman, who donates his time and labor to construct the beds. As word has spread, families of severely jaundiced children around the world have begun contacting him for help.

Jaundice is common in newborns. While more than half exhibit some degree of yellowing, most suffer no ill effects as their livers take over the placenta's job of metabolizing bilirubin. Some infants, however, need help to rid themselves of the compound before rising levels cause irreversible brain damage or death. Treatment usually involves exposure to fluorescent light that can break down bilirubin in the skin.

Franco is one of about 300 people worldwide with a serious genetic condition called Crigler-Najjar Syndrome, or CNS. These patients lack a liver enzyme necessary for bilirubin excretion. The blood bilirubin levels of infants with CNS skyrocket shortly after birth and remain high even after treatment. A liver transplant is the only cure.

"Without a transplant, these kids are jaundiced for the rest of their lives," said Vreman. Although intensive phototherapy can usually control bilirubin levels, the treatment becomes less effective over time and common childhood illnesses or injury can cause disastrous spikes. Missing even one phototherapy session can also cause an ominous rise.

Nightly phototherapy has many downsides. Patients have trouble sleeping on the beds, which can be hot, uncomfortable and -- obviously -- brightly lit. Usually they must sleep naked without blankets to maximize their exposure to the light. Young children in particular may rebel against their unorthodox sleeping arrangements and sneak out of bed during the night.

"I asked myself ‘what can I do about this?'" said Vreman. Although he knew he couldn't solve all the problems, in 1998 he designed a bed that was at least comfortable and portable. The bed looks like a camping cot with a sheer polyester fabric hammock suspended over a bank of fluorescent light tubes. The tubes are contained in a rugged plastic case that can be folded in half for transport. The mesh allows the light to penetrate to the patient while at the same time providing a comfortable sleeping surface.

Vreman and several volunteers including his wife and young grandchildren, assemble and test the comfort of the beds, which weigh about 60 pounds and cost roughly $1,000 to make. The dimensions of each bed are tailored to the size of the child, and can be adjusted as the child grows.

Vreman provides the bed to the patients at cost. "I get paid in kindness, actually," he said, adding that he has formed close relationships with many of the families.

Although the bed travels well, Vreman and his colleagues -- including Daniel S. Seidman, MD, and David K. Stevenson, MD, the Harold K. Faber Professor of Pediatrics in the School of Medicine -- aren't satisfied. They've been investigating using blue light-emitting diodes, similar to the lights used in traffic signals, to break down bilirubin. This light source is much cooler and more intense than fluorescent bulbs. Its narrow wavelength is also more efficient in degrading bilirubin in the laboratory. A recent study of LED treatment of healthy, jaundiced, full-term infants in Jerusalem showed that it was as effective as traditional phototherapy in reducing bilirubin levels.

Vreman recently received nearly $17,000 from the Dutch Crigler-Najjar Foundation to aid in the construction of the portable beds using the blue LEDs. Vreman, who is Dutch, maintains close ties with the foundation, and he and his associates plan to test the first LED beds in Rotterdam in September. Vreman has also received past support from the Stanford Office of Technology Licensing's Birdseed fund, which sponsors prototype development.

Test could help doctors detect newborns at risk for severe jaundice (3/14/01)