Ergonomically designed portable seat cushion

Abstract

A portable cushion that minimizes the blocking of blood circulation, stress, and pain in the femoral region caused by sitting on a chair for long hours or an extended time is provided. The overall shape of the cushion resembles human lungs connected to each other at the upper part with an upper surface that is flat, except for two wing portions. The wings are in a convex shape. The cushion is made of EP (Ethylene-Propylene Copolymer) rubber foam. A straight shallow center groove is concavely developed on the upper surface of the cushion along the direction of the wings. Two concave grooves, resembling hemi-oval shapes being cut along the long center axis thereof are developed on the flat upper surface of the seat cushion to receive ischial tuberosities of a user. A shell-shaped concave groove for receiving the coccyx of the user is developed on the rear part of the flat upper surface of the cushion between the two hemi-oval shape grooves. The front side of the cushion, between the two wings, is caved in for receiving and positioning of genitals of the user. The unique geometry of the cushion reduces the pressure to the ischial tuberosities and the coccyx of a user by maximizing the contact area and distribute the user's weight throughout the surface, while minimizing the blocking of blood circulation by minimizing the contact area of the wings of the cushion and the rear part of the thighs of the user.

1 . A seat cushion resembling a human lungs connected to each other at the upper part with an upper surface that is flat except two wing portions, which are in a convex shape with round shape tips, made of EP (Ethylene-Propylene Copolymer) rubber foam.  
   
   
       2 . A seat cushion of  claim 1 , wherein 1) a straight shallow center groove of hemi-tube shape with 4.76 mm width by 2.38 mm depth is concavely developed on the upper surface of the cushion dividing the cushion into two geometrically identical shapes, 2) two concave ischial tuberosities receiving grooves located symmetrically apart from the center groove and positioned on the middle of the flat upper surface of the cushion with an angle to the center groove, resembling hemi-oval shape of being cut along the long center axis thereof to have length of the longer axis 140 mm and the length of the shorter axis 120 mm, and having depth in the range of 18 mm to 30 mm depends on the size of the cushion, are developed on the flat upper surface of the seat cushion, 3) a shell shaped concave groove having depth in the range of 5 mm to 8 mm for receiving the coccyx of a user is located between the rear sides of the two hemi-oval shape grooves for receiving ischial tuberosities of a user developed on the flat upper surface of the cushion, 4) a front side, between the two wing portions, is caved in with a radius of 45 mm for receiving and positioning of genitals of the user to allow free blood circulation, and 5) two convex wings portions are developed to contact with the rear part of the thighs of the of a user along the length of the leg.  
   
   
       3 . A seat cushion of  claim 1 , wherein the angle between the horizon surface and the inner surface of the ischial tuberosite-receiving groove that locates close to the center groove is in the range of 25 to 30 degrees for men and 35 to 40 degrees for women.