The purpose of this present invention is designed to slowly, steadily, and smoothly change the body support points to vary the effective area of body support on the bed with slow, constant oscillations, in the directions of the width and length of the mattress support and having two sets of drive systems (DS) attached to the chassis (4) intended to support all components, such as the electric motor (7), driven by a power drive (PWM) in the control panel (PC), said electric motor (7) being fitted with gear (8) connected to another gear (9) and a minimum pitch (10), which drives the worm thread vertical shaft (11) intended to move the flat or arched mattress support (2) vertically and the coupling (13) that carries out the vertical coupling of the tip (12) of the vertical shaft (11), which allows adjustment of the coupling (13) and tip (12) of the vertical shaft (11) to the lateral movements between the tip (12) of the vertical shaft (11) and the flat or arched mattress support (2) resulting from transversal oscillations； the rotation shaft (5A) support (5), which couples with the cylindrical shaft (3) attached to the arched mattress support (2), the equipment's chassis (4), and the noise and vibration absorbing cushions (6) as well as the support (14) of hoods (15) and (16) that surround and protect the vertical screw shaft (11).La présente invention réduit les risques de formation d'escarres en changeant régulièrement et en douceur les points d'appui du corps pour faire varier la zone efficace d'appui des protubérances osseuses du corps sur la peau comprimant celle-ci contre le lit, ce qui entraîne la réduction, le plus proche possible de l'annulation, du degré de pression qu'exercent au cours du temps le poids du corps contre le lit, ainsi que des zones d'appui restreintes, empêchant que les zones à risque de faible circulation sanguine sous l'effet du poids du corps continuent à subir une ischémie, avec pour résultat un débit sanguin accru vers ces parties du corp
