39 research outputs found
Automatic Heart Rate Detection during Sleep Using Tracheal Audio Recordings from Wireless Acoustic Sensor
Background: Heart rate is an essential diagnostic parameter indicating a patientâs condition.
The assessment of heart rate is also a crucial parameter in the diagnostics of various sleep disorders,
including sleep apnoea, as well as sleep/wake pattern analysis. It is usually measured using an electrocardiograph (ECG)âa device monitoring the electrical activity of the heart using several electrodes
attached to a patientâs upper bodyâor photoplethysmography (PPG). Methods: The following paper
investigates an alternative method for heart rate detection and monitoring that operates on tracheal
audio recordings. Datasets for this research were obtained from six participants along with ECG
Holter (for validation), as well as from fifty participants undergoing a full night polysomnography
testing, during which both heart rate measurements and audio recordings were acquired. Results:
The presented method implements a digital filtering and peak detection algorithm applied to audio
recordings obtained with a wireless sensor using a contact microphone attached in the suprasternal
notch. The system was validated using ECG Holter data, achieving over 92% accuracy. Furthermore,
the proposed algorithm was evaluated against whole-night polysomnography-derived HR using
Bland-Altmanâs plots and Pearsonâs Correlation Coefficient, reaching the average of 0.82 (0.93 maximum) with 0 BPM error tolerance and 0.89 (0.97 maximum) at ±3 BPM. Conclusions: The results
prove that the proposed system serves the purpose of a precise heart rate monitoring tool that can
conveniently assess HR during sleep as a part of a home-based sleep disorder diagnostics process
Mitochondrial DNA mutations in cancer - from bench to bedside
Mitochondria are cell organelles mostly known for their production of ATP through oxidative phosphorylation. As suggested over 70 years ago by O. Warburg and recently confirmed with molecular techniques, alterations in respiratory activity and mitochondrial DNA appear to be a common feature of malignant cells. Somatic mtDNA mutations have been reported in many types of cancer cells. MtDNA mutation pattern may enhance the specificity of cancer diagnostics, detection and prediction of tumor growth rate and patients' outcome. Therefore it may be used as a molecular cancer bio-marker. Nevertheless recently published papers list a large number of mitochondrial DNA mutations in many different cancer types, but their role in cell patophysiology remains unsummarized. This review covers the consequences of mitochondrial genes mutations for human cell physiology and proliferation. We underline effects of mtDNA mutation-resulting amino acid changes in the respiratory chain proteins' structure, and propose changes in mitochondrial protein function. Mutations are critically evaluated and interpreted in the functional context and clinical utility of molecular mitochondrial research is summarized and new perspectives for 'mitochondrial oncology' suggested