Abstract: A method and apparatus for controlling blood withdrawal and infusion flow rate with the use of a pressure controller. The pressure controller uses pressure targets based upon occlusion limits that are calculated as a function of flow. The controller has the ability to switch from controlling withdrawal pressure to controlling infusion pressure based upon the detection of an occlusion. The controller distinguishes between partial and total occlusions of the withdrawal vein providing blood access. Depending on the nature of occlusion, the controller limits or temporarily reverses blood flow and, thus, prevents withdrawal vessel collapse or reverses blood flow to quickly infuse blood into the vessel without participation from operator.

Abstract: A method and apparatus for controlling blood withdrawal and infusion flow rate with the use of a pressure controller. The pressure controller uses pressure targets based upon occlusion limits that are calculated as a function of flow. The controller has the ability to switch from controlling withdrawal pressure to controlling infusion pressure based upon the detection of an occlusion. The controller distinguishes between partial and total occlusions of the withdrawal vein providing blood access. Depending on the nature of occlusion, the controller limits or temporarily reverses blood flow and, thus, prevents withdrawal vessel collapse or reverses blood flow to quickly infuse blood into the vessel without participation from operator.

Abstract: A weight scale including: a measuring electronic circuit including a filter; a load cell attachable to a support housing and generating a load signal processed by the filter of the electronic circuit; a spring coupled to the load cell to apply a force to the load cell, wherein the load signal is indicative of the force, and a scale beam connected to the spring and to the support housing, wherein a weight to be measured is attached to the scale beam and the force applied by the spring is indicative of the weight, and wherein natural frequencies of the weight and spring is higher than a cut-off frequency of the filter.

Abstract: A blood volume control method has been developed including: monitoring a condition of a patient (such as hematocrit (Hct)), wherein the condition is indicative of blood volume in the patient; automatically determining that the condition indicates a low blood volume in the patient; automatically infusing an infusion solution into the patient in response to the determination of a low blood volume, and automatically adjusting the infusion to maintain the monitored condition at a predetermined value.

Abstract: A method and apparatus for controlling blood withdrawal and infusion flow rate with the use of a pressure controller. The pressure controller uses pressure targets based upon occlusion limits that are calculated as a function of flow. The controller has the ability to switch from controlling withdrawal pressure to controlling infusion pressure based upon the detection of an occlusion. The controller distinguishes between partial and total occlusions of the withdrawal vein providing blood access. Depending on the nature of occlusion, the controller limits or temporarily reverses blood flow and, thus, prevents withdrawal vessel collapse or reverses blood flow to quickly infuse blood into the vessel without participation from operator.

Abstract: A method and apparatus are disclosed for controlling blood flow through an extracorporeal blood circuit having a controller comprising the steps of: withdrawing the blood from a withdrawl blood vessel in a patient into the extracorporeal circuit, treating the blood in the circuit and infusing the treated blood into the patient; detecting an occlusion which at least partially blocks the withdrawl or infusion of the blood; reducing the blood flow rate and the rate of filtration in response to the occlusion, and further prompting the patient to move his arm in an effort to alleviate the occlusion.