Critical reviews in biomedical engineering
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This article reviews the various modeling techniques for neuromonitoring depth of anesthesia (DOA). Traditional techniques such as parametric, predictive, optimal, and adaptive modeling, proportional, integral, derivative (PID) modeling, together with modern techniques such as bispectral-based, artificial neural-network-based, fuzzy logic, and neuro-fuzzy modeling, bring us to the current state of the art in DOA neuromonitoring. This article reviews historical information about each of the modern techniques and provides an example demonstrating its implementation; reviews drug pharmacokinetic/pharmacodynamic (PK/PD) and drug interaction PK/PD modeling techniques for a balanced total intravenous anesthesia (TIVA) administration; and discusses the existing technical problems and clinical challenges, suggesting new techniques necessary for the future development of a DOA monitoring and control system.
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Crit Rev Biomed Eng · Jan 2001
ReviewThe state of head injury biomechanics: past, present, and future: part 1.
This article is the first of two parts of a comprehensive survey of the biomechanics of head injury since its inception in 1939 in the United States, the separation being made for temporal and spatial reasons. The second portion of this material will be published at a later time in this journal. The discussion will be almost exclusively limited to nonpenetrating events. ⋯ It is hoped that this survey will serve as a resource for researchers and practitioners in the area of traumatic head injury and provide a roadmap for further investigations that are urgently needed. For example, this could include a determination of the rate of absorption of blood emitted from broken vessels, and, hopefully, some correlation between mechanical failure and physiological dysfunction of the various relevant tissues of the head. Although a good beginning has been initiated, additional information at the neuronal and axonal level concerning the effect of loading on function as well as age-related changes in geometry and tissue properties is also needed.
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Crit Rev Biomed Eng · Jan 2000
Artifact-tolerant controllers for automatic drug delivery in anesthesia.
This article presents a method for treating measurement artifacts in model-based control systems. A nonlinear modification to the usual observer structure is introduced to prevent the measurement artifacts from winding up the controller states. It is shown how stability of the closed loop system can be analyzed and an example of a successful application in a clinical study is provided.
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The expansion and contraction of the lungs and heart result in movement of the chest wall that can be detected and monitored to determine respiration and heart rate. A prototype non-contact Vital Signs Monitor (VSM) has been developed which uses very low power, high frequency Doppler radar to detect these motions. Digital signal processing (DSP) techniques, imbedded in the VSM, are used to extract heart and respiration rate information from the resultant waveform. ⋯ With careful signal processing and analysis, it may be possible to extract clinically useful information about cardiac condition, function, or performance from the surface-motion waveform. This could provide a safe, inexpensive, and painless addition to the diagnostic and monitoring tools currently available to cardiologists. Although there are technical obstacles to overcome in filtering gross motions of the subject, the VSM offers significant advances over conventional methods of measuring heart and respiration rate.
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Crit Rev Biomed Eng · Jan 1987
ReviewA critical review of EMG-controlled electrical stimulation in paraplegics.
This review presents a description and provides a comparative performance evaluation of EMG control vs. other approaches to controlling functional electrical stimulation (FES) in upper-motor-neuron paraplegics to provide them with a certain degree of walking ability with walker support. EMG control is considered in terms of a combination of above-lesion EMG control and below-lesion response-EMG control. The above-lesion EMG is to control the activation of different limb functions involved in standing up and walking via FES. ⋯ It is shown that below-lesion EMG control of stimulation levels can be used independent of above-lesion EMG control. Below-lesion EMG control can thus be combined also with hand-switch control or, in case of low level upper-motor-neuron lesions, with pelvis control. Hence, and since FES-activated walking is as good as its control, we conclude that EMG control should be given serious consideration in any FES walking.(ABSTRACT TRUNCATED AT 400 WORDS)