Different between velocity ratio and efficiency

Velocity ratio of simple machine is the ratio of distance travelled by effort to the distance travelled by load in the machine. The efficiency of a simple machine is defined as the ratio of useful work done by machine (output work) to the total work put into the machine (input work).

Making sure the equipment is cleaned daily and insuring proper hygiene is kept up with the working staff.

Few days to several months depending on the severity of the stroke ;