A portable sampling or testing device for pharmacokinetics and physiology studies and a method for using the device in conducting tests on stationary or moving animals, or human test subjects, is disclosed. The device includes an apparatus for conducting a test on a freely moving subject, or a device which may be moved by a technician to be positioned over an immobile subject, such as a premature infant or unconscious human subject in an intensive care ward. The device is designed and sized to be mobile. In one embodiment, the device comprises a wheeled cart which may be moved by a human test subject operably connected to it. In another embodiment, the device comprises a wheeled carriage positioned above an animal which wears a sling connected to the device. The device may include an uninterruptible power supply. The method provides for sampling bodily fluids or acquiring physiological readings from the test subject. The method provides for removal of body fluids with or without reintroduction of the withdrawn bodily fluids back into the freely moving subject.
