| 摘要 |
A method for detecting Helicobacter pylori in a subject's gastroenteral tract involves measuring a change in resistance of an electronic or electrochemical sensor, notably a polypyrrole film, which is caused by ammonia, on exposure to gas from the subject's lungs and/or stomach. Depending on the magnitude of the change (if any) a positive or negative result is indicated visually by electronics means such as LED's 20, 22. In a preferred embodiment, two sensors 16a, 16b are used. One of these receives a sample of gas 24 which has passed through an ammonia-absorbing means 30 such as sodium dihydrogen phosphate or copper sulphate on a porous frit to provide a corrected baseline value for the ammonia. Porous frit 28 balances the gas flow to the two sensors. An antacid or sparkling water may be administered orally to a subject before the test. The chambers 2a, 2b can be expandable and can have an exit vent to assist gas flow. An alkaline desiccant may be provided in the common passageway 32. |
