Airbag for blood pressure measuring device and method of manufacturing the same

An airbag for a blood pressure measuring device for fixing a blood pressure measuring cuff to an upper arm portion of a person to be measured, the airbag comprising:

• a first main sheet member having first peripheral edge portions;
• a second main sheet member having second peripheral edge portions,
• wherein the first and second main sheet members are welded or bonded together at the first and second peripheral edge portions to form a bag body, which defines an air chamber therein, the bag body having a longitudinal direction and a width direction perpendicular to the longitudinal direction, and the first and second peripheral edge portions each including a longitudinal side that extends in the longitudinal direction;
• at least one constricted portion formed by welding a specified area of the first main sheet member, which includes a specified portion of the longitudinal side and extends in the width direction toward a center of the bag body, to a specified area of the second main sheet member, which corresponds to the specified area of the first main sheet member, to narrow a size of the air chamber in the width direction at a location of the at least one constricted portion, the location of the at least one constricted portion being narrower than the overall width of the air chamber;
• a first sub sheet member and a second sub sheet member respectively corresponding to the first main sheet member and the second main sheet member, each of the first and the second sub sheet members being disposed inside or outside of a corresponding main sheet member of the first and second main sheet members, occupying a wider region than the at least one constricted portion including the at least one constricted portion,
• wherein the first and second sub sheet members are stacked and welded or bonded to the first and second main sheet members at the at least one constricted portion, and at a distance away from the longitudinal side of the corresponding main sheet member, each of the first and second sub sheet members being welded or bonded to the corresponding main sheet member at a center near portion, the center near portion being distanced away from the at least one constricted portion in the width direction toward the center of the bag body.