Purdue News
Purdue News
The BioLogic-DT dialysis system, developed by HemoCleanse Inc. of West Lafayette, pulls toxins from blood using activated charcoal and charged atoms. The device, which originated at Purdue University, was approved by the Federal Drug Administration for use in comatose patients with acute hepatic failure.
"The dialysis system has been proven successful in treating patients with liver failure or drug overdose," says Dr. Stephen R. Ash, a Lafayette physician and associate professor of comparative medicine at Purdue. "For patients with acute liver failure, the device is especially effective if they are caught during the early stages of coma, which is generally one of the first complications to develop."
Ash began working on the device in 1975 at Purdue's Biomedical Engineering Center. As co-founder and chairman of HemoCleanse Inc., located in Purdue's Research Park, he has helped carry the new technology from the laboratory to the market.
The system is being used in six countries to treat patients with liver failure and drug overdose. The system should be ready to ship in this country by early May, after the FDA finalizes its inspection of the United Medical Manufacturing Co. in Indianapolis, where the system is made.
The liver serves several important functions, including filtering and destroying bacteria and other toxic substances, and helping break down and eliminate certain proteins and other substances that cannot be used by the body.
During acute liver failure, toxic substances in the body build up and reach the brain, leading to a coma.
The BioLogic-DT dialysis system is similar to a hemodialysis machine used in treating kidney failure, but it is designed to selectively withdraw only those agents normally filtered by the liver, such as ammonia, waste products produced by cells, bacteria, and toxins derived from alcohol, drugs and environmental poisons.
"This device is much more selective than kidney dialysis machines, which use a different process that often filters out things the body needs, such as electrolytes and nutrients," Ash said.
The new system draws a patient's blood through a filtering membrane and then returns cleansed blood to the patient. A suspension of activated charcoal and charged particles binds to agents to be withdrawn, and actively removes such agents from the patient.
To help patients maintain a proper chemical balance, the BioLogic-DT contains a suspension system that can be preloaded with nutrients and chemicals to be returned to the patient during treatment.
"The lower the blood concentration of these substances, the greater the return of the substances to the patient," Ash said.
Because the liver also functions to store and provide sugar to the body, this monitoring system also is used to maintain proper blood glucose levels in the patient during treatment. The charcoal also can be preloaded with specific amino acids, peptides, hormones, or any other chemicals deemed beneficial to the patient.
Unlike a kidney dialysis machine, however, the BioLogic-DT is not designed for long-term care, Ash said. "The machine is designed to take over liver function while the liver heals, or until a patient can receive a transplant."
In 1987, the FDA approved clinical studies of the system to treat patients with acute liver failure and severe coma. More than half the patients recovered normal functioning of the liver or improved sufficiently to undergo a liver transplant operation.
Ash said his company already has orders for more than 19 of the units, which will sell for $60,000.
Ash and his research group at HemoCleanse have produced a similar device, called the BioLogic-HT, that heats patients' blood to destroy bacteria and viruses. The BioLogic-HT is being used as an experimental treatment for patients with AIDS.
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Source: Dr. Stephen Ash, (765) 463-9540
Writer: Susan Gaidos, (765) 494-2081; Internet, susan_gaidos@purdue.edu
