1 Calories Burned For Walking: 4.6 km/h (13 minutes per km). 2  Calories Burned For Walking: 4 km/h (15 minutes per km). 3  Calories Burned For Walking: 3.15 km/h (19 minutes per km).
The first true hypodermic syringe was created by Alexander Wood in 1853. He modified a regular syringe, which at that time was used for treating birthmarks, by adding a needle. He then used this new device for introducing morphine into the skin of patients who suffered from sleeping disorders.
John Hopps invented the first cardiac pacemaker in 1950. Then, William Greatbatch made a new, more modified, version of the pacemaker that we use today. The first artificial heart was made by Dr. Robert K. Jarvik.