Naming difficulties may be rank ordered along a continuum. Items are rank ordered in terms of their ability to be named, which is correlated with their frequency. This type of picture-naming test is also useful in the examination of children with learning disabilities and the evaluation of brain-injured adults.
The Jarvik-7 heart was developed by American scientist Robert Jarvik and his mentor, Willem Kolff. In 1982, Seattle dentist Dr. Barney Clark was the first person implanted with the Jarvik-7, the first artificial heart intended to last a lifetime.
The first cardiac pacemaker was invented in the year 1950 by Canadian John Hopps. In the year 1958, Wilson Greatbatch invented the first implantable pacemaker. The internal pacemaker is a device that regulates the rhythm of the heart by using electrical impulses.he first cardiac pacemaker was invented in the year 1950 by Canadian John Hopps. In the year 1958, Wilson Greatbatch invented the first implantable pacemaker. The internal pacemaker is a device that regulates the rhythm of the heart by using electrical impulses.