Invert gamepad button to avoid RSI

The driving game Slipstream requires nearly uninterrupted pressing of my Logitech Dual Action gamepad's "gas pedal" button for minutes at a time.
My physical therapist agrees that my immersion in the game, my inability to squeeze that button no harder than required, is what's given me my first Repetitive Strain Injury (this was once called Pac Man Thumb.)

Can I invert that key binding, so squeezing that button means releasing the gas pedal?
Or can I buy a different gamepad that can do that?