Background: Nowadays, the most widely used types of wearable sensors in gait analysis are inertial sensors. The aim of the study was to assess the agreement between two different systems for measuring gait parameters (inertial sensor vs. electronic walkway) on healthy control subjects (HC) and patients with Parkinson's disease (PD). Methods: Forty healthy volunteers (26 men, 14 women, mean age 58.7 ± 7.7 years) participated in the study and 24 PD patients (19 men, five women, mean age 62.7 ± 9.8 years). Each participant walked across an electronic walkway, GAITRite, with embedded pressure sensors at their preferred walking speed. Concurrently a G-Walk sensor was attached with a semi-elastic belt to the L5 spinal segment of the subject. Walking speed, cadence, stride duration, stride length, stance, swing, single support and double support phase values were compared between both systems. Results: The Passing-Bablock regression slope line manifested the values closest to 1.00 for cadence and stride duration (0.99 ≤ 1.00) in both groups. The slope of other parameters varied between 0.26 (double support duration in PD) and 1.74 (duration of single support for HC). The mean square error confirmed the best fit of the regression line for speed, stride duration and stride length. The y-intercepts showed higher systematic error in PD than HC for speed, stance, swing, and single support phases. Conclusions: The final results of this study indicate that the G-Walk system can be used for evaluating the gait characteristics of the healthy subjects as well as the PD patients. However, the duration of the gait cycle phases should be used with caution due to the presence of a systematic error.
- Publication type
- Journal Article MeSH
INTRODUCTION AND HYPOTHESIS: Quantitative characterization of the birth canal and critical structures before delivery may provide risk assessment for maternal birth injury. The objective of this study was to explore imaging capability of an antepartum tactile imaging (ATI) probe. METHODS: Twenty randomly selected women older than 21 years with completed 35th week of pregnancy and a premise of vaginal delivery were enrolled in the feasibility study. The biomechanical data were acquired using the ATI probe with a double-curved surface, shaped according to the fetal skull and equipped with 168 tactile sensors and an electromagnetic motion tracking sensor. Software package COMSOL Multiphysics was used for finite element modeling. Subjects were asked for assessment of pain and comfort levels experienced during the ATI examination. RESULTS: All 20 nulliparous women were successfully examined with the ATI. Mean age was 27.8 ± 4.1 years, BMI 30.7 ± 5.8, and week of pregnancy 38.8 ± 1.4. Biomechanical mapping with the ATI allowed real-time observation of the probe location, applied load to the vaginal walls, and a 3D tactile image composition. The nonlinear finite element model describing the stress-strain relationship of the pelvic tissue was developed and used for calculation of Young's modulus (E). Average perineal elastic modulus was 11.1 ± 4.3 kPa, levator ani 4.8 ± 2.4 kPa, and symphysis-perineum distance was 30.1 ± 6.9 mm. The pain assessment level for the ATI examination was 2.1 ± 0.8 (scale 1-4); the comfort level was 2.05 ± 0.69 (scale 1-3). CONCLUSIONS: The antepartum examination with the ATI probe allowed measurement of the tissue elasticity and anatomical distances. The pain level was low and the comfort level was comparable with manual palpation.
- MeSH
- Adult MeSH
- Elasticity Imaging Techniques * MeSH
- Humans MeSH
- Young Adult MeSH
- Pelvic Floor * diagnostic imaging MeSH
- Perineum diagnostic imaging MeSH
- Parturition MeSH
- Feasibility Studies MeSH
- Pregnancy MeSH
- Imaging, Three-Dimensional MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Young Adult MeSH
- Pregnancy MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
We report a new NMR-scale purification procedure for two recombinant wild type fragments of the stromal interaction molecule 1 (STIM1). This protein acts as a calcium sensor in the endoplasmic reticulum (ER) and extends into the cytosol accumulating at ER - plasma membrane (PM) junctions upon calcium store depletion ultimately leading to activation of the Orai/CRAC channel. The functionally relevant cytosolic part of STIM1 consists of three coiled coil domains, which are mainly involved in intra- and inter-molecular homomeric interactions as well as coupling to and gating of CRAC channels. The optimized one-step rapid purification procedure for two 15N,13C isotope-labeled cytosolic coiled coil fragments, which avoids the problems of previous approaches. The high yields of soluble well folded 15N,13C isotope-labeled cytosolic coiled coil fragments followed by detergent screening provide for initial NMR characterization of these domains. The longer 30.5 kDa fragment represents the largest STIM1 wild type fragment that has been recombinantly prepared and characterized in solution without need for mutation or refolding.
- MeSH
- Chromatography, Affinity MeSH
- Dynamic Light Scattering MeSH
- Electrophoresis, Polyacrylamide Gel MeSH
- Isotope Labeling MeSH
- Nitrogen Isotopes chemistry isolation & purification MeSH
- Carbon Isotopes chemistry isolation & purification MeSH
- Humans MeSH
- Neoplasm Proteins chemistry isolation & purification MeSH
- Nuclear Magnetic Resonance, Biomolecular MeSH
- Stromal Interaction Molecule 1 chemistry isolation & purification MeSH
- Protein Domains MeSH
- Recombinant Proteins chemistry isolation & purification MeSH
- Solubility MeSH
- Protein Folding MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The fast and efficient detection of foodborne pathogens is a societal priority, given the large number of food-poisoning outbreaks, and a scientific and technological challenge, given the need to detect as little as 1 viable cell in 25 gr of food. Here, we present the first approach that achieves the above goal, thanks to the use of a micro/nano-technology and the detection capability of acoustic wave sensors. Starting from 1 Salmonella cell in 25 ml of milk, we employ immuno-magnetic beads to capture cells after only 3 h of pre-enrichment and subsequently demonstrate efficient DNA amplification using the Loop Mediated Isothermal Amplification method (LAMP) and acoustic detection in an integrated platform, within an additional ½ h. The demonstrated 4 h sample-to-analysis time comes as a huge improvement to the current need of few days to obtain the same result. In addition, the work presents the first reported Lab-on-Chip platform that comprises an acoustic device as the sensing element, exhibiting impressive analytical features, namely, an acoustic limit of detection of 2 cells/μl or 3 aM of the DNA target and ability to detect in a label-free manner dsDNA amplicons in impure samples. The use of food samples together with the incorporation of the necessary pre-enrichment step and ability for multiple analysis with an internal control, make the proposed methodology highly relevant to real-world applications. Moreover, the work suggests that acoustic wave devices can be used as an attractive alternative to electrochemical sensors in integrated platforms for applications in food safety and the point-of-care diagnostics.
- MeSH
- Acoustics instrumentation MeSH
- Food Analysis instrumentation MeSH
- Biosensing Techniques instrumentation MeSH
- Equipment Design MeSH
- DNA, Bacterial analysis genetics MeSH
- Food Contamination analysis MeSH
- Lab-On-A-Chip Devices MeSH
- Humans MeSH
- Limit of Detection MeSH
- Milk microbiology MeSH
- Foodborne Diseases microbiology MeSH
- Food Microbiology MeSH
- Salmonella genetics isolation & purification MeSH
- Salmonella Infections microbiology MeSH
- Animals MeSH
- Sound MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Evaluation Study MeSH
Hippotherapy employs locomotion impulses that are emitted from the back of a horse while the horse is walking. These impulses stimulate the rider's postural reflex mechanisms, resulting in training of balance and coordination. The aim of the present study was to assess the changes in magnitude and distribution of the contact pressure between the rider and the horse during a series of hippotherapy lessons. The monitored group, consisting of four healthy women (mean age 22.75 years, mean body weight 59.75 kg, mean height 167.25 cm) without any previous horse riding experience, received five 20 minute-lessons lessons in a three-week period. Hippotherapy was given on a 15-year-old thoroughbred mare. An elastic pad (Novel Pliance System, 30 Hz, 224 sensors) was used for pressure magnitude evaluation. The maximum pressure value was increased (p<.05) in the event of a second measurement (5th lesson). The pressure exerted on the rider upon contact of the rear limbs was higher than upon contact of the front limbs (p<.01). The size of the center of pressure (COP) deviations in the anteroposterior direction reduced (p<.05) with the number of lessons received. With the growing experience of the participant, an increase in pressure occurred on contact of her body and the horse's back as well as in the stability of the COP movement.
- MeSH
- Gait physiology MeSH
- Physical Conditioning, Animal physiology MeSH
- Horses physiology MeSH
- Humans MeSH
- Locomotion physiology MeSH
- Young Adult MeSH
- Posture physiology MeSH
- Reference Values MeSH
- Reflex physiology MeSH
- Exercise Movement Techniques methods MeSH
- Exercise Therapy methods MeSH
- Learning MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Young Adult MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
V našem experimentu jsme použili metodu TVS k detekci mechanických změn axiálního systému. Tyto mechanické změny mohou být podkladem pro pocit diskomfortu během monotónního zatížení během jízdy v automobilu. Metoda TVS je založena na aplikaci harmonického buzení plynule se měnícího od 5 Hz do 160 Hz na obratle C7 a L5. Toto vlnění se přenáší podél axiálního systému a akcelerometrickými snímači je snímáno zrychlení všech trnových výběžků obratlů, kterými se vlnění šíří mezi C7 až S1. Na základě naměřených dat lze vyhodnotit změnu mechanických vlastností páteře před a po hypokinéze a frekvenčním zatížení při jízdě v automobilu. Náš výzkum prokázal, že metoda TVS je vhodná pro detekci změn mechanických vlastností axiálního systému. Dále bylo prokázáno, že změny způsobené monotónním a frekvenčním zatížením ovlivňují způsob přenosu vlnění axiálním systémem subjektů. Z našich naměřených dat vyplývá, že můžeme subjekty srovnávat spíše intraindividuálně než interindividuálně. Zjistili jsme, že zdravá a flexibilní páteř osciluje jako elastická tyč a je schopna absorbovat více mechanické energie a spojení na páteři jsou více flexibilní. Rezonanční frekvence zdravé a flexibilní páteře se při našich měřeních objevuje mezi 40 a 60 Hz nebo výše. Ve většině případů nacházíme po jízdě v automobilu vyšší tlumení a nižší přenos vibrací. U některých subjektů se objevuje odlišná reakce na zatížení v hrudní a bederní páteři.
In our measurements, we used TVS method to detect mechanical changes of axial system. These mechanical changes can be base for discomfort feeling during monotonous driving in the car. The TVS method is based on the use of consequent application of continuously changing harmonic stimuli, which periodically differ between 5 Hz and 160 Hz, to the vertebrae C7 and L5. This wave is carried through the axial system and its acceleration on the spinous processes between C7 and S1 is scanned with the help of accelerometric sensors. According to the measured data, it is possible to identify changes of the mechanical properties of the human spine before and after applying hypo kinesis and frequency loading by the car ride. The research results proved the fact, that the TVS method is suitable for detection of the mechanical changes of axial system. It was also proved that changes caused by a monotonic and frequency loading influence the way of waves transfer through the axial system of the observed participants. From our data results, that we can compare the subjects more intraindividual than interindividual. We found out that healthy and flexible spine oscillates like elastic bar. It is able to absorb more mechanical energy with higher elasticity and the spinal joints are more flexible. The resonant frequency of the healthy and flexible spine lies between 40 and 60 Hz or higher. In most of the cases we found higher damping and lower transmission of the vibrations after the loading. By some of the subjects we can find different reaction in thoracic and lumbar spine to the loading.
Research of degradable hydrogel polymeric materials exhibiting high water content and mechanical properties resembling tissues is crucial not only in drug delivery systems but also in tissue engineering, medical devices, and biomedical-healthcare sensors. Therefore, we newly offer development of hydrogels based on poly(2-hydroxyethyl methacrylate-co-2-(acetylthio) ethyl methacrylate-co-2-methacryloyloxyethyl phosphorylcholine) [P(HEMA-ATEMA-MPC)] and optimization of their mechanical and in vitro and in vivo degradability. P(HEMA-ATEMA-MPC) hydrogels differed in chemical composition, degree of crosslinking, and starting molar mass of polymers (15, 19, and 30 kDa). Polymer precursors were synthesized by a reversible addition fragmentation chain transfer (RAFT) polymerization using 2-(acetylthio)ethyl methacrylate containing protected thiol groups, which enabled crosslinking and gel formation. Elastic modulus of hydrogels increased with the degree of crosslinking (Slaughter et al., 2009) [1]. In vitro and in vivo controlled degradation was confirmed using glutathione and subcutaneous implantation of hydrogels in rats, respectively. We proved that the hydrogels with higher degree of crosslinking retarded the degradation. Also, albumin, γ-globulin, and fibrinogen adsorption on P(HEMA-ATEMA-MPC) hydrogel surface was tested, to simulate adsorption in living organism. Rat mesenchymal stromal cell adhesion on hydrogels was improved by the presence of RGDS peptide and laminin on the hydrogels. We found that rat mesenchymal stromal cells proliferated better on laminin-coated hydrogels than on RGDS-modified ones.
- MeSH
- Biocompatible Materials pharmacology MeSH
- Hydrogels * MeSH
- Rats MeSH
- Methacrylates MeSH
- Mesenchymal Stem Cells * MeSH
- Polyhydroxyethyl Methacrylate MeSH
- Tissue Engineering MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Článek se zabývá nárůstem přítlačné patelofemorální síly v důsledku působení ortézy kolenního kloubu na patelu. Snaží se odpovědět na otázku, do jaké míry zvyšuje silové působení ortézy zátěž patelofemorálního kloubu během normálních lokomočních pohybů, a je-li z tohoto důvodu opodstat- něná přítomnost patelárního otvoru, který má silové působení ortézy na patelu redukovat. Byly porovnány čtyři sériově vyráběné ortézy určené pro postižení patelofemorálního skloubení dostupné na našem trhu. Velikost síly vyvíjené ortézou na patelu byla snímána senzorem z vodivého elastického materiálu ve čtyřech polohách v rozmezí rozsahu pohybu kolenního kloubu při chůzi (0 – 50° flexe). Provedený experiment přinesl tyto závěry: – se stoupající flexí kolenního kloubu roste přítlačná síla ortézy na patelu; – měření neprokázalo velké rozdíly ve velikosti síly vyvíjené ortézou na patelu v závislosti na materiálu ani konstrukci ortézy; – síly vznikající v důsledku aplikace ortézy a působící jako přídavné zatížení patelofemorálního kloubu jsou ve srovnání s přítlačnou silou patelofemorálního skloubení zanedbatelné, a z tohoto důvodu není třeba vyžadovat u posuzovaného typu ortéz kolenního kloubu existenci patelárního otvoru.
Article is dealing with an incerease of patelofemoral force as a result of reaction of the knee brace on the patella. It tries to respond to the question how much the reaction of knee brace increases the stress in patello-femoral joint during ordinary locomotional movements. It also deals with the essence of patellar opening in the knee brace which is supposed to decrease the force on patella. Four serially produced braces determinated for involvement of patelofemoral joint compactness available on our market were compared. Magnitude of the reaction between brace and patela was scanned by a sensor from conducting elastical material in four positions during walking in range from 0 to 50 degrees. Realization of the experiment brought these results: – with growing flexion of the knee joint increases the force on patella; – measurement did not certify big differences of the reaction in relation to material or construction of the brace; – forces arisen by an aplication of the knee brace reacting like additional load with patello-femoral joint are negligible in comparison with the force of patello-femoral joint. Therefore it is not necessary to require the patellar opening on judged type of braces.
The aim of this study was to obtain a detailed analysis of the relationship between the finger arterial compliance C [ml/mm Hg] and the arterial transmural pressure P(t) [mm Hg]. We constructed a dynamic plethysmograph enabling us to set up a constant pressure P(css) [mm Hg] and a superimposed fast pressure vibration in the finger cuff (equipped with a source of infra-red light and a photoelectric sensor for the measurement of arterial volume). P(css) could be set on the required time interval in steps ranging between 30 and 170 mm Hg, and on sinusoidal pressure oscillation with an amplitude P(ca) (2 mm Hg) and a frequency f (20, 25, 30, 35, 40 Hz). At the same time continuous blood pressure BP was measured on the adjacent finger (Portapres). We described the volume dependence of a unitary arterial length on the time-varying transmural pressure acting on the arterial wall (externally P(css)+P(ca).sin(2pif), internally BP) by a second-order differential equation for volume. This equation was linearized within a small range of selected BP. In the next step, a Fourier transform was applied to obtain the frequency characteristic in analytic form of a complex linear combination of frequency functions. While series of oscillations [P(ca), f] were applied for each P(css), the corresponding response of the plethysmogram was measured. Amplitude spectra were obtained to estimate coefficients of the frequency characteristic by regression analysis. We determined the absolute value: elastance E, and its inverse value: compliance (C=1/E). Then, C=C(P(t)) was acquired by applying sequences of oscillations for different P(css) (and thus P(t)) by the above-described procedure. This methodology will be used for the study of finger arterial compliance in different physiological and pathological conditions.
- MeSH
- Arteries physiology MeSH
- Diagnostic Techniques, Cardiovascular * instrumentation MeSH
- Blood Pressure MeSH
- Humans MeSH
- Young Adult MeSH
- Models, Cardiovascular MeSH
- Plethysmography methods MeSH
- Compliance MeSH
- Fingers MeSH
- Aged MeSH
- Vibration MeSH
- Check Tag
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
