ABSTRACT
The study of oxygen uptake (VÌo2) dynamics during walking exercise transitions adds valuable information regarding fitness. However, direct VÌo2 measurements are not practical for general population under realistic settings. Devices to measure VÌo2 are associated with elevated cost, uncomfortable use of a mask, need of trained technicians, and impossibility of long-term data collection. The objective of this study was to predict the VÌo2 dynamics from heart rate and inputs from the treadmill ergometer by a novel artificial neural network approach. To accomplish this, 10 healthy young participants performed one incremental and three moderate constant work rate treadmill walking exercises. The speed and grade used for the moderate-intensity protocol was related to 80% of the VÌo2 response at the gas exchange threshold estimated during the incremental exercise. The measured VÌo2 was used to train an artificial neural network to create an algorithm able to predict the VÌo2 based on easy-to-obtain inputs. The dynamics of the VÌo2 response during exercise transition were evaluated by exponential modeling. Within each participant, the predicted VÌo2 was strongly correlated to the measured VÌo2 ( = 0.97 ± 0.0) and presented a low bias (~0.2%), enabling the characterization of the VÌo2 dynamics during treadmill walking exercise. The proposed algorithm could be incorporated into smart devices and fitness equipment, making them suitable for tracking changes in aerobic fitness and physical health beyond the infrequent monitoring of patients during clinical interventions and rehabilitation programs.
Subject(s)
Energy Metabolism/physiology , Exercise/physiology , Oxygen Consumption/physiology , Oxygen/metabolism , Walking/physiology , Adult , Exercise Test/methods , Female , Heart Rate , Humans , Male , Neural Networks, Computer , Physical Exertion/physiology , Young AdultABSTRACT
Multiparametric MRI has shown considerable promise as a diagnostic tool for prostate cancer grading. Diffusion-weighted MRI (DWI) has shown particularly strong potential for improving the delineation between cancerous and healthy tissue in the prostate gland. Current automated diagnostic methods using multiparametric MRI, however, tend to either use low-level features, which are difficult to interpret by radiologists and clinicians, or use highly subjective heuristic methods. We propose a novel strategy comprising a tumor candidate identification scheme and a hybrid textural-morphological feature model for delineating between cancerous and non-cancerous tumor candidates in the prostate gland via multiparametric MRI. Experimental results using clinical multiparametric MRI datasets show that the proposed strategy has strong potential as a diagnostic tool to aid radiologists and clinicians identify and detect prostate cancer more efficiently and effectively.