A Mechatronic Pneumatic Device to Improve Diastolic Function by Intermittent Action on Lower Limbs

Individuals with walking disability, as a result of pathological conditions or traumas, show a reduction in left ventricle end diastolic volume (EDV). In fact EDV is closely related to the blood pressure gradient between the postcaval vein and the right atrium which, during locomotion, is partially due to the calf veins squeezing caused by the rhythmic contraction of the triceps surae and the crushing of the sole of the foot's veins. In this study, a mechatronic device was applied to nineteen healthy voluntary participants' lower limbs to test cardiodynamic response to a mechanical intermittent stimulation. The device consisted of inflatable bladders embedded in two shells and acting on the skin of the calf and foot of both legs. The pressure trend on the legs was regulated by a portable programmable logic controller. During the compression protocol to the legs, which involved some sequences of activation-deactivation following a peristaltic compression having a caudal-rostral trend, EDV, assessed by the impedance cardiography technique, increased of about 10% up the pre-test value. The legs compression protocol imposed by means of our pneumatic device might be useful to avoid the negative consequences for cardiovascular performance caused by de-conditioning status linked to walking disabilities.