Journal of clinical monitoring and computing
-
J Clin Monit Comput · Feb 2008
Comparative StudyCan photoplethysmography variability serve as an alternative approach to obtain heart rate variability information?
Heart rate variability (HRV), extracted from an electrocardiogram, is known to be a noninvasive indicator reflecting the dynamic interplay between perturbations to cardiovascular function and the dynamic response of the cardiovascular regulatory system. Photoplethysmography (PPG) is a noninvasive method to monitor arterial oxygen saturation on a continuous basis. Given the rich cardiovascular information in the PPG signal, and the ubiquity and simplicity of pulse oximetry, we are investigating the feasibility of acquiring dynamics pertaining to the autonomic nervous system from PPG waveforms. ⋯ We compare PPGV to HRV by computing time and frequency domain parameters often associated with HRV measurements, as well as approximate entropy calculations. Our results demonstrate that the parameters of PPGV are highly correlated with the parameters of HRV. Thus, our results indicate that PPGV could be used as an alternative measurement of HRV.
-
J Clin Monit Comput · Feb 2008
Comparative Study Clinical TrialNear-infrared spectroscopy to monitor peripheral blood flow perfusion.
Non-invasive evaluation of peripheral perfusion may be useful in many contexts including peri-operative monitoring. We validated a novel non-invasive spectroscopy technique to assess peripheral perfusion. This method, which is based on the measurement of tissue saturation variations after an ischemic period, was compared to strain gauge plethysmography and radionuclide plethysmography. The technique uses near-infrared spectroscopy (NIRS) to determine the rate of change of forearm tissue saturation during reactive hyperemia. ⋯ The NIRS technique appears well suited for the non-invasive evaluation of limb perfusion.
-
J Clin Monit Comput · Feb 2008
Comparative StudyThe impact of a clinical information system in an intensive care unit.
Although clinical information systems (CISs) have been available and implemented in many Intensive care Units (ICUs) for more than a decade, there is little objective evidence of their impact on the quality of care and staff perceptions. This study was performed to compare time spent charting with pen and paper patient data versus time spent with the new electronic CIS and to evaluate staff perceptions of a CIS in an ICU. ⋯ The implementation of a CIS was associated with a reduced time spent for daily activity and a positive medical and nursing staff perception.
-
J Clin Monit Comput · Dec 2007
A new paradigm for the design of audible alarms that convey urgency information.
The current international standard (IEC 60601-1-8) stipulates that medical device audible alarms should be priority-encoded and validated for efficacy. Evidence suggests that the melodic alarms described in the standard are not functioning as originally intended. We present a multi-disciplinary, human factors paradigm for audible alarm development whereby urgency information is encoded via modulation of the physical characteristics of sounds. We also test the feasibility of this approach using information measures. ⋯ The proposed paradigm is feasible, and it offers an evidence-based strategy for alarm sound design and testing. This approach would be performed before implementation of new alarm sounds in clinical settings, and should result in development of alarm sounds that satisfy the requirements of priority-encoding and validation.