Learn More
Ubiquitous blood pressure (BP) monitoring is needed to improve hypertension detection and control and is becoming feasible due to recent technological advances such as in wearable sensing. Pulse transit time (PTT) represents a well-known potential approach for ubiquitous BP monitoring. The goal of this review is to facilitate the achievement of reliable(More)
This letter presents a novel closed-loop approach to anesthetic drug concentration estimation using clinical-effect measurement feedback. Compared with the open-loop prediction used in current target-controlled infusion systems, closed-loop estimation exploits the discrepancy between the measured and predicted clinical effects to make corrections to the(More)
GOAL We tested the hypothesis that the ballistocardiogram (BCG) waveform could yield a viable proximal timing reference for measuring pulse transit time (PTT). METHODS From 15 healthy volunteers, we measured PTT as the time interval between BCG and a noninvasively measured finger blood pressure (BP) waveform. To evaluate the efficacy of the BCG-based PTT(More)
The oscillometric fixed-ratio method is widely employed for non-invasive measurement of systolic and diastolic pressures (SP and DP) but is heuristic and prone to error. We investigated the accuracy of this method using an established mathematical model of oscillometry. First, to determine which factors materially affect the errors of the method, we applied(More)
In an effort to open up new opportunities in individualized anesthesia care, this paper presents a dynamic dose-response model of propofol that relates propofol dose (i.e., infusion rate) directly to a clinical effect. The proposed model consists of a first-order equilibration dynamics plus a nonlinear Hill equation model, each representing the transient(More)
OBJECTIVE Most automatic cuff blood pressure (BP) measurement devices are based on oscillometry. These devices estimate BP from the envelopes of the cuff pressure oscillations using fixed ratios. The values of the fixed ratios represent population averages, so the devices may only be accurate in subjects with normal BP levels. The objective was to develop(More)
This investigation aimed to develop a pediatric pharmacodynamic model of propofol-induced tidal volume depression towards an ultimate goal of developing a dosing schedule that would preserve spontaneous breathing following a loading dose of propofol. Fifty two ASA 1 and 2 children aged 6–15 year presenting for gastrointestinal endoscopy were enrolled.(More)
Knowledge of the anesthesia drug concentration in a patient during a surgical procedure has potential to improve patient monitoring and control of drug administration. High-fidelity estimates of anesthesia drug concentration would allow anesthesiologists to make relevant low-level dose adjustment as well as high-level clinical decisions. The estimated drug(More)
A disturbance observer-based nonlinear vehicle stability controller is proposed in this paper. The lumped disturbance to the vehicle yaw rate dynamics has been estimated using the disturbance observer. The disturbance is due to the uncertain factors such as tire forces, vehicle parameters and hydraulic actuator parameters. The estimated disturbance has been(More)