A Quantitative Method for Studying Human Arterial Baroreflexes

We describe a new system that delivers precise, stereotyped pressure changes to the human neck and elicits neurally-mediated heart rate changes.

The centerpiece of this system is a Silastic chamber that is strapped to the anterior neck. This chamber is connected to a stepping-motor controlled bellows assembly. A strain-gauge transducer measures the intensity of pressure changes. The entire system is controlled by microprocessors, and both stimuli and responses are displayed on a digital oscilloscope.

The end-product of this system is a reproducible baroreceptor stimulus-cardiac response relation that can be recorded rapidly and safely in astronauts in space.