This is not the case regarding the ventilator, which offers no capability for being directly controlled by a computer generated electrical signal. Control of its oxygen concentration knob must therefore depend upon some motor linked to this knob, and driven by signals provided by a cable from one of the computer’s output ports. To effect this communication, additional hardware must thus be retrofitted to the ventilator. Furthermore, since this project’s effectiveness has yet to be proven, and ventilators are quite expensive, the following constraint is assumed: Should the retrofit be removed, the ventilator is returned to its pristine condition, with no permanent sign that any retrofit ever existed. This condition precludes even the use of mounting holes, and imposes severe constraints upon the additional hardware to be added.
