What does the EPFX-USB acctually do ? The QXCI has the ability to scan the clients body , like a Virus scan in a computer. What the machine is looking for is abnormalities such as hormonal/ vitamin deficiencies, viruses, food sensitivities, and allergies. The computer then reports on the body reactivity and indicates the body's need. The information obtained is different than the allopathic way of checking disease with x-rays and blood test.