Sip-and-puff

It is commonly used to control a motorized wheelchair by quadriplegics with very high injury to their spinal cord or people with ALS.

[1] Devices that use SNP technology require specific amounts of air pressure to be "sipped" or "puffed" by the user.

Note that the words "hard" and "soft" are relative to the user and depend on their breathing abilities.

With the assistance of an aid or technician, the user will program the SNP device to recognize their body's ability to produce hard sips/puffs and soft sips/puffs.

The mouth-controlled input provide users a simple and effective way to control mouse movement.

The Patient Operated Selector Mechanism (POSM or POSSUM) was developed in the early 1960s, and used a sip-and-puff control mechanism.