Cuff for blood pressure monitor
In a cuff of a blood pressure monitor, a distance along bending of a first expandable portion is set so as to be different from a distance along bending of a second expandable portion at the time of deflation. When a fluid bladder for pressurizing is inflated with a fluid fed thereinto, the second expandable portion expands longer. As a result, force, which is generated on a cuff fixing element which is pushed by the fluid bladder for pressurizing, acts to a vertical direction with respect to an axial direction of a subject.
1. A cuff of a blood pressure monitor, the cuff being configured to be mounted on a predetermined portion of a subject and including a bladder configured to expand to pressurize the predetermined portion of the subject upon inflation with a fluid, the bladder comprising:
an inside belt configured to be placed over the predetermined portion of the subject when the cuff is mounted on the predetermined portion of the subject;
an outside belt disposed over the inside belt;
a first expandable portion connecting a longitudinal side of the inside belt and a corresponding side of the outside belt;
a second expandable portion connecting another longitudinal side of the inside belt and a corresponding side of the outside belt, the second expandable portion being configured to expand more than the first expandable portion when the bladder is inflated with the fluid for pressurizing the predetermined portion of the subject.
2. The cuff of a blood pressure monitor of claim 1 , wherein the first and second expandable portions are configured to be bent inward when the bladder is not inflated with the fluid, and a distance along the bending of the second expandable portion between the inside and outside belts is longer than a distance along the bending of the first expandable portion between the inside and outside belts.
3. The cuff of a blood pressure monitor of claim 1 , wherein the second expandable portion has a larger expansion per unit length upon the inflation with the fluid than the first expandable portion.
4. The cuff of a blood pressure monitor of claim 3 , wherein the first and second expandable portions are made of a same material, and the second expandable portion is thinner than the first expandable portion.
5. The cuff of a blood pressure monitor of claim 3 , wherein the second expandable portion is made of a material having a lower elastic coefficient than a material of which the first expandable portion is made.