Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference
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Conf Proc IEEE Eng Med Biol Soc · Jan 2006
Optimizing deep brain stimulation parameter selection with detailed models of the electrode-tissue interface.
Deep brain stimulation (DBS) is an established clinical therapy for the treatment of Parkinson's disease. However, selecting stimulation parameters for maximal clinical benefit can be a difficult and time consuming process that typically requires a highly trained and experienced individual to achieve acceptable results. To address this limitation we developed a Windows-based software package (StimExplorer) intended to aid the clinical implementation of DBS technology. ⋯ The software then provides theoretically optimal stimulation parameter suggestions, intended to represent the start point for clinical programming of the DBS device. The software system is packaged into a clinician-friendly graphical user interface that allows for interactive 3D visualization. The goals of the StimExplorer system are to educate clinicians on the impact of stimulation parameter manipulation, and improve the customization of DBS to individual patients.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2006
A next generation electronic triage to aid mass casualty emergency medical response.
For years, emergency medical response communities have relied upon paper triage tags, clipboards of notes, and voice communications to share information during medical emergencies. This workflow, however, has proven labor intensive, time consuming, and prone to human error [1]. In collaboration with three EMS groups in the Washington, DC Metropolitan area, we have developed a next generation triage system to improve the effectiveness of emergency response. ⋯ Our system has evolved through three iterations of rapid-development, field-studies, usability reviews, and focus-group interview. This paper summarizes engineering considerations for technologies that must operate under constraints of medical emergencies. It is our hope that the lessons reported in this paper will help technologists in developing future emergency response systems.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2006
Comparative StudyComparison of heart rate variability signal features derived from electrocardiography and photoplethysmography in healthy individuals.
The heart rate variability (HRV) signal is indicative of autonomic regulation of the heart rate (HR). It could be used as a noninvasive marker in monitoring the physiological state of an individual. Currently, the primary method of deriving the HRV signal is to acquire the electrocardiogram (ECG) signal, apply appropriate QRS detection algorithms to locate the R wave and its peak, find the RR intervals, and perform suitable interpolation and resampling to produce a uniformly sampled tachogram. ⋯ We used autoregressive (AR) modeling, Poincare' plots, cross correlation, standard deviation, arithmetic mean, skewness, kurtosis, and approximate entropy (ApEn) to derive and compare different measures from both ECG and PPG signals. This study demonstrated that our PDA-based system was a convenient and reliable means for acquisition of PPG-derived and ECG-derived HRV signals. The excellent agreement between different measures of HRV signals acquired from both methods provides potential support for the idea of using PPGs instead of ECGs in HRV signal derivation and analysis in ambulatory cardiac monitoring of healthy individuals.
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Capnography, the monitoring of expired carbon dioxide (CO2) has been employed clinically as a non-invasive measure for the adequacy of ventilation of the alveoli of the lung. In combination with air flow measurements, the capnogram can be used to estimate the partial pressure of CO2 in the alveolar sacs. In addition, physiologically relevant parameters, such as the extent of CO2 rebreathing, the airway dead space, and the metabolic CO2 production can be predicted. ⋯ In addition, this allowed for a dynamic prediction of the unmeasured alveolar CO2 tension. The method is demonstrated using simulations of the capnogram. The proposed method could aid the clinician in the interpretation of the capnogram.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2006
Continuous cardiac output and left atrial pressure monitoring by pulmonary artery pressure waveform analysis.
We introduce a novel technique for continuous (i.e., automatic) monitoring of cardiac output (CO) and left atrial pressure (LAP) by mathematical analysis of a pulmonary artery pressure (PAP) waveform. To obtain an initial evaluation of the technique, we applied it to PAP waveforms obtained from nine critically ill patients and compared the resulting CO and LAP estimates with standard operator-dependent thermodilution and pulmonary capillary wedge pressure measurements, respectively. We report that the technique achieved an overall CO error of 17.2% and an overall LAP error of 15.8%. With further testing, the technique may ultimately be employed so as to permit, for the first time, continuous CO and LAP monitoring in critically ill patients.