PLETHYSMOGRAPH DEVICE Russian patent published in 2003 - IPC

FIELD: medical engineering. SUBSTANCE: device has chamber having internal cavity for placing extremity under study therein, inflatable cuff for stopping venous blood circulation in the extremity. The cuff has manometer unit and device for measuring extremity volume in achieving venous blood circulation stop. Atmospheric pressure gage, bellows having inlet connection pipe and movable bottom mechanically connected to reciprocating motion drive, micro-compressor, pneumatic tumbler switches, two variable pneumatic air-flow constrictors having inlet and outlet connection pipes and electronic computer device. Device for measuring extremity volume increment when stopping venous blood circulation, is designed as positive pressure gage having inlet connection pipe. Sealing member is designed as inflatable cuff having manometer. The sealing member is positionable in space separating the extremity under study and internal chamber surface generatrix. The inlet connection pipes of the positive pressure gage and the first pneumatic air-flow constrictor and outlet connection pipe of the second pneumatic air-flow constrictor are connected to the internal cavity of the chamber. The micro-compressor is connectable with its inlet to inlet connection pipe of the second pneumatic air-flow constrictor, to inflatable cuff for stopping venous blood circulation and member for sealing the internal cavity of the chamber via corresponding connection pipes. The outlet connection pipe of the second pneumatic air-flow constrictor is connected to atmosphere via pneumatic tumbler. Outlets of the positive pressure gage and atmospheric pressure gage are connected to the electronic computer device. EFFECT: high accuracy in determining modulus of blood circulation intensity without applying additional instruments. 3dwg, 1 tbl