Closed-loop infusion system, both method and apparatus, based on real time urine measurement

A closed loop system for controlled infusion of fluids, medication and diagnostic substances based on real time measurement of urine output of a patient, comprising:

• (a) a urine drop counter including
• (i) a drop chamber,
• (ii) means for successively sensing occurrences of drops of urine within said drop chamber,
• (iii) inlet means having an opening size and configuration adapted to form drops of substantially uniform volume,
• (iv) means to compensate for drop volume variation with variation in urine flow rate;
• and
• (v) outlet means adapted for conducting urine from said chamber to a collection site;
• (b) a small diameter tube connected at one end to said inlet means and adapted in length and configuration for connection at the other end to a bladder catheter to be associated with the patient, the catheter/tube combination including means to prevent rate of urine flow within said tube from exceeding rate of urine production by a patient's renal system;
• (c) comparator means coupled to said drop sensing means to provide monitoring of real time flow rate of said urine based on frequency of drop occurrence and to compare said real time flow rate with a predetermined flow rate selected for the patient, said comparator means including means to provide an error signal output corresponding to a variance detected between the real time and predetermined flow rates;
• (d) regulated infusion means adapted for automatically introducing said fluids, medications and diagnostic substances within said patient at variable infusion rates;
• and
• (e) computer means coupled to (i) the error signal output of the comparator means and (ii) the regulated infusion means, for processing said error signal and for providing an appropriate correction signal to said infusion means for adjusting infusion rates to thereby increase or decrease patient fluid levels or concentrations of medication or diagnostic substances until a null reading is obtained at the comparator based on changes in urine output.