Abstract: A measurement device is disclosed for measuring a change in one or more of a circumference or a perimeter of at least a portion of an object having a surface. The measurement device includes a first part for attachment to the object, a second part having a first portion moveable relative to a first portion of the first part, a determining device for determining a displacement of the first portion of the second part relative to the first portion of the first part caused by the object changing, and a biasing device for biasing the first part and the second part towards engagement. The measured displacement is for use in determining the change in one or more of a circumference or a perimeter of the object.

Abstract: A measurement device is disclosed for measuring a change in one or more of a circumference or a perimeter of at least a portion of an object having a surface. The measurement device includes a first part for attachment to the object, a second part having a first portion moveable relative to a first portion of the first part, a determining device for determining a displacement of the first portion of the second part relative to the first portion of the first part caused by the object changing, and a biasing device for biasing the first part and the second part towards engagement. The measured displacement is for use in determining the change in one or more of a circumference or a perimeter of the object.