| The pressure therapy of medical compression stockings is an effective way to prevent and assist in the treatment of varicose veins of the lower extremities or venous diseases caused by postoperative surgery.It exerts pressure on the lower extremities of the human body through the downward pressure from the ankle to the calf to the thigh.The pressure on the lower extremities is the highest,the lower leg is the second,and the pressure on the thigh is the smallest,thereby compressing the veins of the lower extremities and helping the venous blood to return to the heart.However,there are two main problems with the use of medical compression stockings.One problem is,people with different leg types wear the same size of compression stockings,which may cause the gradient of longitudinal pressure to decrease or the pressure gradient is reversed.Another problem is that after wearing the compression stockings,the pressure difference between the front side and the back side at the same section of the lower leg is large,which may result uneven pressure values at the same section.In order to study and solve these two problems,this topic firstly selected the plain 1:1 twill inlay structure which is widely used in the current compression stockings,and designed the plain 1:1 straight inlay structure、tuck 1:1 twill inlay structure and tuck 2:2 straight inlay structure.Through the trial weaving and testing of the four different fabrics with the same parameters,the plain 1:1 twill inlay structure and the tuck 1:1 twill inlay structure were selected for subsequent research.Then using the orthogonal test method to study the ankles、calves and thighs of three different leg models.Corresponding to different parameters and levels,respectively,studying and testing three kinds of inlay yarns（Ⅰ:2104040D、Ⅱ:2804040D、Ⅲ:4204040D） of two different kinds of structures and the mixed structure fabrics.The mathematical relationships of three kinds of inlay yarns are established and optimized for each parameter and pressure value,and the validity of the models are verified.Mathematical relationships arey1（28）34.633-0.018x1-0.063x2-0.005x3、y2（28）39.385-0.028x1-0.067x2（10）0.001x3、y3（28）47.468-0.04x1（10）0.077x2（10）0.002x3,y 1,y2,and y3 represent pressure values,x1 represents the sizing motor,x2 represents the elongation,and x3 represents the PYF（feeding speed of inlay yarn）.Finally,three subjects were recruited,3D body scanner was used to scan the lower limbs.The circumferences of each section of the subjects were extracted and calculated by MATLAB,together with the established mathematical relationships were used to design the parameters of the stockings and predict the pressure values of the ankle,calf and thigh.Customized medical compression stockings of plain 1:1 twill inlay structure and the mixed structure at the lower legs of the subjects were made.By measuring and analyzing the pressure values of the human body wearing customized compression stockings at ankle,calve and thigh,several conclusions were drawn:the measured values are greater than the predicted pressure values.The reason is that after the human body wearing the compression stockings,the measured pressure values are generated by the common deformation of the human body and the compression stockings;the measured pressure values on the calf back side of the compression stockings of the mixed structure are larger than the pressure values on the calf front side of the stockings of the plain 1:1 twill inlay structure,which indicates that the compression stockings of the mixed structure on calf can facilitate the homogenization of the pressure at the calf section. |
