Baltimore ? Researchers are collaborating on a new, laser-based breath analyzer that can pick up hidden clues about your health.

Doctors already use breath samples to monitor patients with asthma, those in intensive care and others recovering after heart transplants. They are also testing breath-based diagnostic tools designed to detect breast cancer, lung cancer and tuberculosis.

During the last 20 years, Terence Risby, a researcher at Johns Hopkins’ Bloomberg School of Public Health, has asked 50,000 sick children, organ transplant recipients and patients with a variety of diseases to blow into a tube that deposits their breath into a plastic sack.

He has used those breath samples to show that elevated ammonia levels can be a sign of liver and kidney disease, and that increased ethane can signal vitamin deficiencies in children as well as organ damage after transplants.

Risby and colleagues have won a five-year, $15 million grant from the National Science Foundation to develop a laser-based device that could be used to diagnose diseases.