answers: 1982
context: the actual inventor of the balance spring. Huygens was clearly the first to use a spiral balance spring, the form used in virtually all watches to the present day. The addition of the balance spring made the balance wheel a harmonic oscillator like the pendulum in a pendulum clock, which oscillated at a fixed resonant frequency and resisted oscillating at other rates. This innovation increased watches' accuracy enormously, reducing error from perhaps several hours per day to perhaps 10 minutes per day, resulting in the addition of the minute hand to the watch face around 1680 in Britain and 1700 </s> mean "bell", and are derived from the Medieval Latin "clocca", also meaning bell. Indeed, bells were used to mark the passage of time; they marked the passage of the hours at sea and in abbeys. Throughout history, clocks have had a variety of power sources, including gravity, springs, and electricity. Mechanical clocks became widespread in the 14th century, when they were used in medieval monasteries to keep the regulated schedule of prayers. The clock continued to be improved, with the first pendulum clock being designed and built in the 17th century. The earliest mention of candle clocks comes from a </s> pacemaker function has been to attempt to mimic nature by utilizing various inputs to produce a rate-responsive pacemaker using parameters such as the QT interval, pO – pCO (dissolved oxygen or carbon dioxide levels) in the arterial-venous system, physical activity as determined by an accelerometer, body temperature, ATP levels, adrenaline, etc. Instead of producing a static, predetermined heart rate, or intermittent control, such a pacemaker, a 'Dynamic Pacemaker', could compensate for both actual respiratory loading and potentially anticipated respiratory loading. The first dynamic pacemaker was invented by Anthony Rickards of the National Heart Hospital, London, UK, in 1982. Dynamic pacemaking
question: when was the pacemaker invented in what year