A device for urologic post-surgical monitoring.

This article reports on the preliminary development of an instrument that is intended to monitor catheterized, post-TURP patients specifically to assist care-providers in the reduction of clot retention. The primary objective of the instrument is to detect conditions that indicate an alarm condition for which the probability of clot retention is considered to be high. In response to an alarm, intervention by means of increased irrigation flow rate or other action is expected. The density of outflow consisting of the mixture of irrigation fluid, urine, and blood from the prostate, is monitored optically. Multiple transducer sites along the catheter improve the monitoring by minimizing the effects of bubbles and particulates in the stream. Development of algorithms for processing the data have concentrated on the use of fuzzy logic in keeping with the linguistic descriptors used by medical experts. This allows the formulation of decision rules that mimic the knowledge base and syntax used by care providers who judge the conditions of the outflow and make decisions about the patient's condition and the optimum flow rate for irrigation fluid. A laboratory prototype has been completed and tested in vitro; a second-generation prototype has been designed in preparation for a clinical study.

A new open and closed respiration chamber.

A new, fully automated, open and closed respiration chamber has been constructed, which is large enough to accommodate man or comparable sized animals. Metabolic rate is calculated from measured changes in respiratory gas volumes while the system is hermetically sealed. When CO2 concentration reaches a prescribed level, large ports are opened and the chamber is ventilated. By repeating this process, a series of metabolic determinations can be conducted over an extended period. Temperature, humidity and air velocity are fixed, but chamber volume and pressure vary with changes in the respiratory exchange of the animal and/or barometric pressure. Small, rapid changes in gas volumes are monitored by a low-resistance spirometer and large changes accommodated in a second, high-volume, motorized spirometer. Chamber operations, data acquisition and metabolic calculations are performed by a small computer. System calibration with methanol combustion indicates that estimates of respiratory gas exchange are highly accurate over a temperature range from 10-40 degrees C.