Helen Mirren | Helen Keller | Helen | Helen of Troy | Helen Hayes | Helen Clark | Helen Reddy | Helen Frankenthaler | Helen Hunt | Helen Humes | Roger Goodell | Helen Razer | Helen Fielding | Helen Allingham | Helen Storrow | Helen Shaver | Helen Caldicott | Helen Sjöholm | Helen Sharman | Helen Nicol | Helen Morgan | Helen Merrill | Helen Hay Whitney | Helen Hanft | Helen Fein | Helen Dunmore | Helen Callaghan | Helen Baylor | Helen Thomas | Helen Reimensnyder Martin |
In 1940, James D. Hardy, Harold G. Wolff and Helen Goodell of Cornell University introduced the first dolorimeter as a method for evaluating the effectiveness of analgesic medications.