Experimental Design for Distributed Parameter Vector Systems.

We formulate an optimal design problem for the selection of best states to observe and optimal sampling times and locations for parameter estimation or inverse problems involving complex nonlinear nonlinear partial differential systems. An iterative algorithm for implementation of the resulting methodology is proposed.

Experimental Design for Vector Output Systems.

We formulate an optimal design problem for the selection of best states to observe and optimal sampling times for parameter estimation or inverse problems involving complex nonlinear dynamical systems. An iterative algorithm for implementation of the resulting methodology is proposed. Its use and efficacy is illustrated on two applied problems of practical interest: (i) dynamic models of HIV progression and (ii) modeling of the Calvin cycle in plant metabolism and growth.

Comparison of sufentanil, bupivacaine, and their combination for epidural analgesia in obstetrics.

BACKGROUND AND OBJECTIVES: We postulated that epidural sufentanil alone would provide adequate analgesia for labor and delivery. We also considered the possibility that a combination of epidural sufentanil and bupivacaine would demonstrate superior analgesia and fewer side effects when compared with either agent alone. METHODS: Using a randomized, double-blind design, parturients were prospectively assigned to receive intermittent 10-ml doses of 3 micrograms/ml sufentanil in saline (Group S), 1.5 micrograms/ml sufentanil in 0.125% bupivacaine (Group SB), or 0.25% bupivacaine (Group B). Lumbar epidural catheters were placed during the first stage of labor, and a test dose (3 ml 2% lidocaine with 15 micrograms epinephrine) was given, followed by coded study solution. Subsequent doses of study solution were given at the patient's request. Those parturients who remained uncomfortable after 30 minutes were given 10 ml 2% lidocaine and were designated efficacy failures. Patients were evaluated for quality and duration of analgesia for each dose. Neonates were assessed using Apgar scores and the neonatal behavioral assessment scale. Maternal and umbilical venous sufentanil concentrations were measured at the time of delivery. RESULTS: All patients received satisfactory analgesia of similar duration after the first epidural dose. After subsequent doses, women in Group S experienced more efficacy failures (Groups S, SB, and B, respectively, 12 of 26, 5 of 22, and 1 of 25; p less than 0.005) and received briefer, less intense analgesia compared to the other groups. Instrumental delivery was performed more frequently for women in Group B (Groups S, SB, and B, respectively, 0 of 14, 2 of 17, and 7 of 24; p = 0.04). No serious maternal side effects occurred. Apgar and neurobehavioral scores were comparable for all groups, with the exception that Group B infants had higher irritability scores at 1 hour of age (p = 0.003). Neither maternal nor umbilical venous sufentanil concentrations bore a consistent relationship to clinical outcomes. CONCLUSIONS: Epidural sufentanil alone does not reliably provide satisfactory analgesia for labor and delivery. Addition of small amounts of local anesthetic to bolus doses of sufentanil enhances and prolongs the analgesic effect.