Introduction: Respiratory rate is conventionally recorded using nasal thermocouples, spirometers and plethysmographs and is useful in ambulatory monitoring. As ECG is also a commonly used ambulatory diagnostic tool. An attempt has been made to derive respiratory signals from ECG in this study.
Methods and Materials: Development of the algorithm was based on the fact that respiration causes modulation of the R peak in the ECG. This algorithm was applied to signals acquired from Physionet, BioPac and Polysomnograms for validation.
Results: When the ECG-derived respiratory (EDR) signal obtained by applying the algorithm to ECG was correlated with traditionally recorded respiratory signals, the correlation coefficient ranged between 0.7 and 0.75. Besides, the plot of fast Fourier transform (FFT) of both signals was found to be similar.
Conclusions: This study can be further extended for real-time processing of signals in PSG. Besides, it can be used to detect apnoeas in patients undergoing Holter ECG.
Study Objectives: To investigate the association of somatic–psychological complaints (SPCs) and personality traits with insomnia in a clinically unselected sample of adult Indian population. The effects of extraversion (E), neuroticism (N), depression and anxiety, somatic complaints in addition to demographic variables were examined using a questionnaire in patients with insomnia.
Design: A retrospective descriptive design with convenient sampling. A direct interview using a structured questionnaire, which solicited information about sleep, somatic complaints (headache, backache, stiff neck/shoulder, fatigue), psychological variables (anxiety and depression), personality (extraversion, neuroticism) and socio-demographic information was administered.
Setting and Participants: Patients visiting the hospital with chief complaint of disturbed and poor sleep were clinically interviewed. Overall, 150 consecutive patients were selected for the study. Out of 150 subjects, 89 met the inclusion criteria.
Measurements and Results: Those meeting the criteria were administrated the psychometric battery. The cutoff score for poor quality of sleep on Pittsburg Sleep Quality Index (PSQI) was >5, whereas for severe depression and anxiety on Hospital Anxiety and Depression Scale (HADS) was >11. A total of 89 subjects with a mean age of 34.56±12.17 years were examined. Overall, 56% of them had poor quality of sleep, whereas 60% of them suffered from depression and anxiety. Somatic complaints were reported by 76.4% of subjects. Overall, 72% had SPCs and these were more prevalent in younger males and females. Univariate analysis showed that insomnia was significantly associated with age (middle aged), marital status (married), somatic complaints, anxiety, depression and neuroticism.
Conclusions: SPCs were common in patients with insomnia in an unselected sample of an adult Indian population. Neuroticism, somatic and severe psychological complaints seem to have a strong association with insomnia in this population. Further study is needed to examine the casual links between SPCs and insomnia in the Indian population.