The New York Times, Monday, April 5, 1999

Patents

A Bandage With a Microcontroller

Each Monday in its Business section, The New York Times publishes a column on Patents, which covers recently issued patents, events at the United States Patent and Trademark Office (USPTO) and related events. Generally, this column reports between one and five recently issued patents, selected for their likely public interest. This is but a small sample of all newly issued U.S. patents: USPTO issues about 3,300 utility patents per week. On April 5, 1999, about half of the column was devoted to the change to a new Patents Commissioner (USPTO director). The second half of that column, reproduced below, reviewed only one patent, U.S. Pat. No. 5,879,292, for smart bandages. The content of this excerpt is copyrighted by The New York Times. This excerpt is reproduced here as an aid to understanding the smart bandage patent and its significance. For a full and authoritative understanding of the patent, there is no substitute for a critical reading of the original.

By Sabra Chartrand

There are smart cards, smart phones and even smart bombs. Now add smart bandages.

Patients recovering from a wound or from surgery, or receiving treatment for a disease or other health problems may soon wear bandages that can detect the status of their injury or incision, store the data and transmit it to a computer.

Like traditional bandages, this one is made of an absorbant pad with an adhesive strip. But the pad contains a microcontroller and battery. The microcontroller has a contact-sensitive sensor and a timer. The pad also has a data port, so that an external link can be made between the microcontroller and a computer.

Dr. Edward Sternberg, a molecular biologist and biochemist, and his coinventor, Jan-Tjeerd de Faber, an ophthalmologist, designed the bandage initially as an eye patch for children suffering from amblyopia, or "lazy eye," one of the most common childhood eye defects. Children with this condition must be compelled to use their weak eye, so a patch is placed over the stronger eye for several hours each day. But because many patients are under the age of 5, it is often difficult for doctors to get them to follow instructions and stick to an eye-patch schedule. So, Dr. Sternberg and Dr. de Faber came up with the idea of a patch that monitors itself and records the amount of time it is worn.

The microcontroller and timer in the eye patch record a signal when the patch is in contact with the patient, and a second signal when that contact is broken. The time of each signal is then stored in the chip's memory.

Later, the data can be downloaded to a computer via the external data port on the bandage and analyzed by doctors.

Dr. Sternberg is president of a Milwaukee biomedical engineering company called BioKey. He envisions bandages with different sensors to detect the status of infection, healing, the effectiveness of antibiotics and other conditions. One bandage might have a pH sensor to determine oxygen levels in an open wound or incision. That would tell doctors whether the wound was healing or becoming infected.

Too much oxygen is toxic, but too little can hinder tissue growth.

"There's no reason to limit the sensor to anything as simple as a pH sensor," Dr. Sternberg said. "One could have far more sophisticated sensors. There's a strong advantage to having the sensors tailored to the individual bandage.

"If you're designing a bandage to be used by soldiers in the field who may not have easy access to medical care, you want as sophisticated a device as you can get. If you're designing something for use in an intensive care unit with doctors and nurses there 24 hours a day, you may not want the same level of sophistication and cost."

Dr. Sternberg and Dr. de Faber won patent 5,879,292.