Biomechanical qualities of muscles characterize the work-capacity and functional condition of the... more Biomechanical qualities of muscles characterize the work-capacity and functional condition of the neuro-muscular system.
Skin biomechanical parameters (dynamic stiffness, frequency, relaxation time, creep, and decremen... more Skin biomechanical parameters (dynamic stiffness, frequency, relaxation time, creep, and decrement) measured using a myotonometer (MyotonPRO) could inform the management of sclerotic disease. To determine which biomechanical parameter(s) can accurately differentiate patients with sclerotic chronic graft-versus-host disease from post–hematopoietic cell transplant controls, 15 patients with sclerotic chronic graft-versus-host disease and 11 post–hematopoietic cell transplant controls were measured with the myotonometer on 18 anatomic sites. Logistic regression and two machine learning algorithms (least absolute shrinkage and selection operator regression and random forest) were developed to classify subjects. In univariable analysis, frequency had the highest overfit-corrected area under the curve (0.91). Backward stepwise selection and random forest machine learning identified frequency and relaxation time as the optimal parameters for differentiating patients with sclerotic chronic graft-versus-host disease from post–hematopoietic cell transplant controls. Least absolute shrinkage and selection operator regression selected the combination of frequency and relaxation time (overfit-corrected area under the curve = 0.87). Discriminatory ability was maintained when only the sites accessible while the patient is supine (12 sites) were used. We report the distribution of values for these highly discriminative biomechanical parameters, which could inform the assessment of disease severity in future quantitative biomechanical studies of sclerotic chronic graft-versus-host disease.
Upper airway dilator muscles are important in the pathogenesis of obstructive sleep apnea syndrom... more Upper airway dilator muscles are important in the pathogenesis of obstructive sleep apnea syndrome (OSAS). The present study compares changes of tissue properties between the soft palate and tongue in different age groups of apnea patients and healthy subjects. Materials and methods: OSAS patients diagnosed by polysomnography (15 patients - aged 30-70 years; 10 patients - aged 18-29 years) and healthy volunteers (10 subjects - aged 30-70 years; 10 patients - aged 18-29 years) participated in the study. Computerized endopharyngeal myotonometry was used to measure the biomechanical properties - stiffness and elasticity of the soft palate [M. Veldi, V. Vasar, A. Vain, T. Hion, M. Kull, Computerized endopharyngeal myotonometry (CEM): a new method to evaluate the tissue tone of the soft palate in patients with obstructive sleep apnea syndrome, J. Sleep Res. 9 (2000) 279-284; M. Veldi, V. Vasar, T. Hion, M. Kull, A. Vain, Ageing, soft-palate tone and sleep-related breathing disorders, Clin. Physiol. 21 (2001) 358-364] and lingual tissues [M. Veldi, V. Vasar, T. Hion, A. Vain, M. Kull, Myotonometry demonstrates changes of lingual musculature in obstructive sleep apnea, Eur. Arch. Otorhinolaryngol. 259 (2002) 108-112; M. Veldi, V. Vasar, T. Hion, A. Vain, M. Kull, Myotonometry demonstrates changes of soft palate and genioglossal muscle in obstructive sleep apnea, Sleep Med. 4 (Suppl. 1) (2003) S49] during wakefulness. Results: We did not find any statistical differences in tissue properties between the soft palate and the tongue tissues, either stiffness or elasticity, in young non-snorers and young patients of apnea (P > 0.05). The stiffness of the soft palate of middle-aged apnea patients was increased compared with the tongue (P < 0.001). The elasticity of tongue of middle-aged patients of apnea was decreased compared with the soft palate (P < 0.001). Conclusions: The biomechanical properties of the soft palate and the tongue undergo different changes in the case of snoring and upper airway obstruction and ageing.
The first X-ray equipment was built and X-rays were produced in the University of Tartu (UT) in e... more The first X-ray equipment was built and X-rays were produced in the University of Tartu (UT) in early 1896, just months after W. C. Röntgen's discovery. Quite soon the invention was taken into use in diagnostic medicine. It was the beginning of the development and application of medical physics in Estonian hospitals. In the 1920s X-ray equipment was built for clinical use in the Tartu University Hospital. The first special curriculum for medical physics and biomedical engineering was launched in UT in 1994. The joint curriculum pilot project with Tallinn Technical University lasted from 2009 to 2012, while the joint curriculum has been implemented since 2013. 54 Bachelor's level, 42 Master's level and 3 Doctoral students have graduated from the University of Tartu in the field of medical physics and biomedical engineering since 1994. One of the most famous inventions of UT scientists in the field of biomechanics is the myometer invented by Arved Vain. The myometric metho...
Supplementary materials for "Optimal selection of biomechanical parameters to differentiate ... more Supplementary materials for "Optimal selection of biomechanical parameters to differentiate sclerotic chronic graft-versus-host disease patients from post-transplant controls: a cross-sectional study"
Biomechanical qualities of muscles characterize the work-capacity and functional condition of the... more Biomechanical qualities of muscles characterize the work-capacity and functional condition of the neuro-muscular system.
Skin biomechanical parameters (dynamic stiffness, frequency, relaxation time, creep, and decremen... more Skin biomechanical parameters (dynamic stiffness, frequency, relaxation time, creep, and decrement) measured using a myotonometer (MyotonPRO) could inform the management of sclerotic disease. To determine which biomechanical parameter(s) can accurately differentiate patients with sclerotic chronic graft-versus-host disease from post–hematopoietic cell transplant controls, 15 patients with sclerotic chronic graft-versus-host disease and 11 post–hematopoietic cell transplant controls were measured with the myotonometer on 18 anatomic sites. Logistic regression and two machine learning algorithms (least absolute shrinkage and selection operator regression and random forest) were developed to classify subjects. In univariable analysis, frequency had the highest overfit-corrected area under the curve (0.91). Backward stepwise selection and random forest machine learning identified frequency and relaxation time as the optimal parameters for differentiating patients with sclerotic chronic graft-versus-host disease from post–hematopoietic cell transplant controls. Least absolute shrinkage and selection operator regression selected the combination of frequency and relaxation time (overfit-corrected area under the curve = 0.87). Discriminatory ability was maintained when only the sites accessible while the patient is supine (12 sites) were used. We report the distribution of values for these highly discriminative biomechanical parameters, which could inform the assessment of disease severity in future quantitative biomechanical studies of sclerotic chronic graft-versus-host disease.
Upper airway dilator muscles are important in the pathogenesis of obstructive sleep apnea syndrom... more Upper airway dilator muscles are important in the pathogenesis of obstructive sleep apnea syndrome (OSAS). The present study compares changes of tissue properties between the soft palate and tongue in different age groups of apnea patients and healthy subjects. Materials and methods: OSAS patients diagnosed by polysomnography (15 patients - aged 30-70 years; 10 patients - aged 18-29 years) and healthy volunteers (10 subjects - aged 30-70 years; 10 patients - aged 18-29 years) participated in the study. Computerized endopharyngeal myotonometry was used to measure the biomechanical properties - stiffness and elasticity of the soft palate [M. Veldi, V. Vasar, A. Vain, T. Hion, M. Kull, Computerized endopharyngeal myotonometry (CEM): a new method to evaluate the tissue tone of the soft palate in patients with obstructive sleep apnea syndrome, J. Sleep Res. 9 (2000) 279-284; M. Veldi, V. Vasar, T. Hion, M. Kull, A. Vain, Ageing, soft-palate tone and sleep-related breathing disorders, Clin. Physiol. 21 (2001) 358-364] and lingual tissues [M. Veldi, V. Vasar, T. Hion, A. Vain, M. Kull, Myotonometry demonstrates changes of lingual musculature in obstructive sleep apnea, Eur. Arch. Otorhinolaryngol. 259 (2002) 108-112; M. Veldi, V. Vasar, T. Hion, A. Vain, M. Kull, Myotonometry demonstrates changes of soft palate and genioglossal muscle in obstructive sleep apnea, Sleep Med. 4 (Suppl. 1) (2003) S49] during wakefulness. Results: We did not find any statistical differences in tissue properties between the soft palate and the tongue tissues, either stiffness or elasticity, in young non-snorers and young patients of apnea (P > 0.05). The stiffness of the soft palate of middle-aged apnea patients was increased compared with the tongue (P < 0.001). The elasticity of tongue of middle-aged patients of apnea was decreased compared with the soft palate (P < 0.001). Conclusions: The biomechanical properties of the soft palate and the tongue undergo different changes in the case of snoring and upper airway obstruction and ageing.
The first X-ray equipment was built and X-rays were produced in the University of Tartu (UT) in e... more The first X-ray equipment was built and X-rays were produced in the University of Tartu (UT) in early 1896, just months after W. C. Röntgen's discovery. Quite soon the invention was taken into use in diagnostic medicine. It was the beginning of the development and application of medical physics in Estonian hospitals. In the 1920s X-ray equipment was built for clinical use in the Tartu University Hospital. The first special curriculum for medical physics and biomedical engineering was launched in UT in 1994. The joint curriculum pilot project with Tallinn Technical University lasted from 2009 to 2012, while the joint curriculum has been implemented since 2013. 54 Bachelor's level, 42 Master's level and 3 Doctoral students have graduated from the University of Tartu in the field of medical physics and biomedical engineering since 1994. One of the most famous inventions of UT scientists in the field of biomechanics is the myometer invented by Arved Vain. The myometric metho...
Supplementary materials for "Optimal selection of biomechanical parameters to differentiate ... more Supplementary materials for "Optimal selection of biomechanical parameters to differentiate sclerotic chronic graft-versus-host disease patients from post-transplant controls: a cross-sectional study"
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