Techniques For Detecting A Force Acting On A Base Of A Patient Transport Apparatus

A patient transport apparatus for use in loading and unloading into a cargo area of an emergency response vehicle, said patient transport apparatus comprising:

• a base;
• a support frame comprising a patient support surface configured to support a patient;
• a lift mechanism interposed between said base and said support frame and being configured to move between a plurality of vertical configurations including an extended configuration and a retracted configuration, wherein said base and said support frame are separated by a first distance in said extended configuration and a second distance in said retracted configuration, and wherein the first distance is greater than the second distance;
• a user interface configured for engagement by a user to generate a corresponding user input signal;
• a sensor configured to generate a sensor input signal corresponding to a force acting on said base relative to the support frame;
• and
• a controller coupled to said lift mechanism, said user interface, and said sensor, said controller being configured to:
• determine if said user input signal corresponds to an extend command or a retract command;
• determine if the force acting on said base has exceeded a predetermined threshold value based on said sensor input signal;
• drive said lift mechanism toward said extended configuration in response to determining that said user input signal corresponds to said extend command and toward said retracted configuration in response to determining that said user input signal corresponds to said retract command;
• and
• interrupt driving of said lift mechanism between said extended configuration and said retracted configuration to stop motion of said lift mechanism in response to said sensor input signal exceeding said predetermined threshold value.