Blood flow monitoring and control apparatus
First Claim
1. A blood flow monitoring and control apparatus, comprising single needle liquid withdrawal and liquid return means (1) connectable to a patient, blood treating means (4), first artery conduit means (3'"'"') connecting said blood treating means to said single needle means, artery pump means (3) in said first artery conduit means, a single operating condition volume sensing means (5) having an inlet and an outlet, second artery conduit means operatively interconnecting said blood treating means (4) to said inlet of said single operating condition volume sensing means (5), vein conduit means (11'"'"') and vein pump means (11) in said vein conduit means operatively connecting said outlet of said single operating condition volume sensing means (5) to said single needle means to form together with said first conduit means a closed loop flow circuit in which the blood circulates in but one direction, and control means (13) operatively connected to said single operating condition volume sensing means (5) as well as to said artery and vein pump means (3, 11) to control the blood flow in said closed loop flow circuit, said operating condition volume sensing means comprising filling level sensing means 7, 8, 9, 10 for the volumetric measuring of the liquid flowing in said one direction in said closed loop flow circuit, said filling level sensing means providing control signals for a liquid withdrawal phase from said volume sensing means (5) through said vein conduit and vein pump means (11, 11'"'"') and for a liquid return phase to said volume sensing means (5) through said artery conduit and artery pump means (3, 3'"'"'), whereby the liquid withdrawal phase is stopped upon reaching a predetermined first filling level in said volume sensing means (5) and the liquid return phase is started whereas a liquid return phase is stopped upon reaching a predetermined second filling level and vice versa.
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Abstract
The present blood flow monitoring and control apparatus is especially use in connection with the so-called single needle technique, for example, for treatments such as dialysis, perfusion, or diafiltration. The blood pressure control is accomplished by a measuring chamber including a pressure equalizing device operatively connected between the blood cleaning apparatus and the blood pump. Sensors are operatively connected to the volume measuring chamber. The volume sensors provide electric control input signals to a control circuit which in turn controls the blood pumps and/or valves. A reading may be provided on a display or an alarm may be given when the blood pressure or blood quantity or volume is not within predetermined limits as calculated by an electronic computer.
160 Citations
12 Claims
- 1. A blood flow monitoring and control apparatus, comprising single needle liquid withdrawal and liquid return means (1) connectable to a patient, blood treating means (4), first artery conduit means (3'"'"') connecting said blood treating means to said single needle means, artery pump means (3) in said first artery conduit means, a single operating condition volume sensing means (5) having an inlet and an outlet, second artery conduit means operatively interconnecting said blood treating means (4) to said inlet of said single operating condition volume sensing means (5), vein conduit means (11'"'"') and vein pump means (11) in said vein conduit means operatively connecting said outlet of said single operating condition volume sensing means (5) to said single needle means to form together with said first conduit means a closed loop flow circuit in which the blood circulates in but one direction, and control means (13) operatively connected to said single operating condition volume sensing means (5) as well as to said artery and vein pump means (3, 11) to control the blood flow in said closed loop flow circuit, said operating condition volume sensing means comprising filling level sensing means 7, 8, 9, 10 for the volumetric measuring of the liquid flowing in said one direction in said closed loop flow circuit, said filling level sensing means providing control signals for a liquid withdrawal phase from said volume sensing means (5) through said vein conduit and vein pump means (11, 11'"'"') and for a liquid return phase to said volume sensing means (5) through said artery conduit and artery pump means (3, 3'"'"'), whereby the liquid withdrawal phase is stopped upon reaching a predetermined first filling level in said volume sensing means (5) and the liquid return phase is started whereas a liquid return phase is stopped upon reaching a predetermined second filling level and vice versa.
Specification