Patent ID: 7404801

Claim:
An automatic blood pressure monitor for measuring the arterial blood pressure at a location on a patient, said monitor comprising: a) an inflatable blood flow occluding bladder; b) a pressure generator for inflating said blood flow occluding bladder; c) means for deflating said blood flow occluding bladder; d) means for detecting, computing and producing an output indicative of the pressure in the artery; e) means for convening said output into visible signals; f) means for displaying said signals; g) means for supplying energy to said monitor; and h) a strap for supporting said monitor at said location on said patient; characterized in that, said pressure generator comprises a propellant supply chamber containing a predetermined quantity of propellant, said chamber having an exit valve for releasing said propellant; said means for deflating said blood flow occluding bladder comprises a permanently open small exit hole of predetermined size in said blood flow occluding bladder, said permanently open small exit hole being valve free; said energy supply means is necessary only for supplying energy for the operation of said detecting, computing, converting, and display means; and all of the elements comprising said monitor are attached to or are an integral pan of said strap; whereupon said predetermined quantity of propellant, the volume of said flow occluding bladder and the ratio of the cross-sectional area of the opening in said exit valve and the cross-sectional area of the valve free exit hole in said blood flow occluding bladder are such that, upon opening said exit valve said propellant flowing into said blood flow occluding bladder will inflate said blood flow occluding bladder to an initial maximum pressure greater than the pressure necessary to occlude the flow of blood at said location, said pressure in said blood flow occluding chamber decreasing from said maximum value, at a predetermined rate, to a value less than the diastolic pressure at said location in said artery as said propellant escapes from said blood flow occluding bladder through said exit hole; wherein for at least part of the process for measuring the arterial blood pressure, said propellant is flowing into and out of said blood flow occluding bladder simultaneously.