The functionality of handcuffs has changed little over the last fifty years, but in the near future, things can change dramatically. In November of last year’s Patent Bolt found a request from the company Scottsdale Inventions for "Apparatus and system for an extension of restraint the detainee."
This new device can be "tuned to electric shocks when predetermined conditions are fulfilled." Activation can be done by remote control. In the patent application, this function is compared with the work Teyzera.
The list of features does not end there, because they are able to enter a "liquid, gaseous, coloring, irritating, medical, sedative, transdermal medication, such as dimethyl sulfoxide, paralytics, the drugs prescribed by the prisoner, or any combination of the above," and therefore completely exclude direct involvement of staff.
These cuffs can be programmed to operate on the principle of the electric collar, striking prisoner shock in case of an attempt to go beyond the permitted zone. But before applying shock electric shock, the warning light will light up and you hear a squeak.
The request included photos of the prototype, which means that these handcuffs have received your actual implementation and will soon be available police.