Patent ID: 6889564

Claim:
A peak flow meter comprising: a substantially hollow housing consisting of a top portion having a slot and a scale disposed proximate to said slot, a bottom portion, an air inlet and at least one air outlet; a flow restriction disposed within said housing and in fluid communication with said air inlet, said flow restriction being dimensioned to create a back pressure within said housing; a vane assembly disposed within said housing, said vane assembly comprising a vane, a post to which said vane is fixedly attached, and an adjustable hub attached to said bottom portion of said housing, wherein said adjustable hub is dimensioned to allow said post to be rotated to a predetermined position; a torsion spring comprising a first end engaged with said adjustable hub and a second end engaged with said post; and an indicator for indicating a peak flow rate of air based upon a movement of said vane, wherein said indicator is a visual indictor movably disposed within said slot, said visual indicator being dimensioned to be moved by said vane when said vane is rotated by said stream of air and to maintain a peak flow position within said slot upon cessation of said stream of air; wherein a user blows a stream of air into said air inlet, a first portion of said stream of air passes through said flow restriction and is vented through said at least one air outlet, a second portion of said stream of air contacts said vane and causes said vane to rotate against said torsion spring, and said indicator indicates the peak flow rate of said stream of air based upon said movement of said vane.