Biomedical sciences instrumentation
-
Comparative Study Clinical Trial
Validity of self-assessment outcome questionnaires: patient-physician discrepancy in outcome interpretation.
Patient outcome following total hip arthroplasty (THA) was evaluated using a previously described patient assessment outcome index questionnaires. The questionnaire was distributed to 263 patients who underwent cementless THA. One hundred and three patients responded to the self-administered questionnaire and had updated clinical evaluation. ⋯ We also found that patients' expectations had changed from their preoperative expectations. Although outcome measures developed and administered by clinicians are subject to bias from several sources, results of this study suggest that self administered patient outcome measures also have their limitations. The validity of self-administered patient outcome questionnaires can be severely impacted by the patients' understanding of the questions asked, as even the most seemingly simple questions are subject to misinterpretation.
-
The LifeShirt system, a garment with integrated sensors connected to a handheld computer, allows recording of a wide variety of clinically important cardiorespiratory data continuously for extended periods outside the laboratory or clinic. The device includes sensors for assessment of physical activity and posture since both can affect physiological activation and need to be controlled. Speaking is another potential confounding factor in the interpretation of physiological data. ⋯ This criterion was equally successful in distinguishing speaking from sitting quietly. Discriminant analyses indicated that linear combinations of IE-ratio and a variety of other parameters did not reliably improve classification accuracy across tasks and replications. These results demonstrate the high efficacy of RIP-derived IE-ratio for speech detection and suggest that auditory recording is not necessary for detection of speech in ambulatory assessment.
-
Clinical Trial
Relationships among spectral measures of baroreflex sensitivity and indices of cardiac vagal control.
Traditionally baroreflex sensitivity (BRS) has been assessed with pharmacological approaches such as phenylephrine infusion. Recently, non-invasive approaches using spectral analytic techniques have been employed to combine heart rate and blood pressure variability parameters to estimate BRS (the alpha index). Some authors have argued that BRS assessed at different frequencies of cardiovascular variabilities provide identical information and they should be combined into a single index of BRS based on total variability. ⋯ Correlations examining the relationships among BRS and various (e.g. log, normalized) indices of high frequency heart period variability (HF) were calculated for the total sample and by gender. Results indicated that the different BRS indices do not have the same relationship to all indices of HF. The results suggest that an aggregation of the power across bands is problematic at best, and indicates the need to examine the various frequency components separately.