Human-machine interface

An apparatus, comprising:

• a. a user interface device constructed to be worn so that a least a portion of the user interface device is located at a top of a wrist for a hand of a person, the user interface device comprising:
• a biopotential sensor configured for sensing biopotentials at the top of the wrist, wherein the biopotentials are related to activity of muscles that control the hand and fingers, the biopotential sensor providing as an output a biopotential signal indicative of the sensed biopotentials;
• and
• a location sensor configured for sensing location of the wrist, the location sensor providing as an output a location signal indicative of the sensed location;
• and
• b. a responsive device constructed to communicate with the user interface device and configured to:
• receive data based on the biopotential signal and data based on the location signal, and
• cause performance of an action based on a primitive gesture based on a pose of the hand and a location of the wrist and detected based on the biopotential signal and the location signal.

A responsive device constructed to receive, from a user interface device worn at a top of a wrist, data based on a biopotential signal and data based on a location signal,

• the responsive device comprising:
• a processing system comprising a processing device and computer storage, the computer storage having computer program instructions stored thereon which, when processed by the processing device, configure the responsive device to:
• use the received data to identify one cell of a set of two or more spatially organized virtual cells, the respective cells being associated with corresponding actions;
• and
• cause performance of the action associated with the identified cell.