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131 results on '"in vivo measurement"'

101. Photodynamic therapy dosimetry using multiexcitation multiemission wavelength: toward real-time prediction of treatment outcome.

Author

Mousavi, Monirehalsadat, Moriyama, Lilian Tan, Grecco, Clovis, Nogueira, Marcelo Saito, Svanberg, Katarina, Kurachi, Cristina, and Andersson-Engels, Stefan

Subjects
*PHOTODYNAMIC therapy, *TREATMENT effectiveness, *RADIATION dosimetry, *FORECASTING, *OPTICAL properties, *ALTITUDES
Abstract

Evaluating the optical properties of biological tissues is needed to achieve accurate dosimetry during photodynamic therapy (PDT). Currently, accurate assessment of the photosensitizer (PS) concentration by fluorescence measurements during PDT is typically hindered by the lack of information about tissue optical properties. In the present work, a hand-held fiber-optic probe instrument monitoring fluorescence and reflectance is used for assessing blood volume, reduced scattering coefficient, and PS concentration facilitating accurate dosimetry for PDT. System validation was carried out on tissue phantoms using nonlinear least squares support machine regression analysis. It showed a high correlation coefficient (>0.99) in the prediction of the PS concentration upon a large variety of phantom optical properties. In vivo measurements were conducted in a PDT chlorine e6 dose escalating trial involving 36 male Swiss mice with Ehrlich solid tumors in which fluences of 5, 15, and 40 J cm − 2 were delivered at two fluence rates (100 and 40 mW cm − 2). Remarkably, quantitative measurement of fluorophore concentration was achieved in the in vivo experiment. Diffuse reflectance spectroscopy (DRS) system was also used to independently measure the physiological properties of the target tissues for result comparisons. Then, blood volume and scattering coefficient measured by the fiber-optic probe system were compared with the corresponding result measured by DRS and showed agreement. Additionally, tumor hemoglobin oxygen saturation was measured using the DRS system. Overall, the system is capable of assessing the implicit photodynamic dose to predict the PDT outcome. [ABSTRACT FROM AUTHOR]

Published
2020
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102. Development of Necrobia rufipes (De Geer, 1775) (Coleoptera: Cleridae) under constant temperatures and its implication in forensic entomology.

Author

Hu, Guoliang, Wang, Man, Wang, Yu, Tang, Huanhuan, Chen, Rufeng, Zhang, Yingna, Zhao, Yunlong, Jin, Jiaying, Wang, Yifan, Wu, Maowang, and Wang, Jiangfeng

Subjects
*CLERIDAE, *FORENSIC entomology, *INSECT larvae, *INSECT morphology, *INSECT development
Abstract

• The development of Necrobia rufipes was monitored from 22 to 36 °C. • The morphological indexes of larvae were measured in vivo. • Developmental models were established which can be used to estimate PMI min. • A linear discriminant analysis and classifiers for N. rufipes instars were determined. • This study provides data for PMI min estimation using N. rufipes. After the death of humans or animals, the odors released at different stages of decay attract various insects, and other arthropods, to the corpses. Therefore, the development of insects, and other arthropods present on corpses, can be assessed to estimate the minimum postmortem interval since death. In general, necrophagous blow flies are the insects that first colonize corpses. With progressing decay, other necrophagous and predatory insects arrive at the corpses, which will develop on or around these either by feeding directly on the corpses or by prey on other immature insects. Beetles (Coleoptera) mainly arrive at the corpses during the later stages of decay, and play important roles in cases with longer postmortem intervals. Necrobia rufipes (De Geer, 1755) (Coleoptera: Cleridae) is an important stored-product species with world-wide distribution. Moreover, it is also a forensically important insect species. At temperatures of 22, 25, 28, 31, 34, and 36 °C (±0.5 °C), the developmental periods from egg to adult were 113.20 ± 2.96, 66.16 ± 3.22, 50.61 ± 1.95, 38.26 ± 2.48, 37.97 ± 2.40, and 31.20 ± 2.11 days, respectively. In vivo measurements obtained the morphological indexes of larvae. The growth curve and the equation of the relationship between development time, body lengths, and mesonotum widths were simulated. The isomorphen diagram model, the isomegalen diagram model, and the thermal summation model were established. In addition, the widths of head capsules and pronota of larvae at different instars were determined by cluster analysis. Classifiers were created and validated by linear discriminant analysis. [ABSTRACT FROM AUTHOR]

Published
2020
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105. The brain interstitial system: Anatomy, modeling, in vivo measurement, and applications

Author

Fan Yuan, Yong Zhao, Aqeel Javeed, Hongbin Han, and Yiming Lei

Subjects
0301 basic medicine, Neuroscience(all), health care facilities, manpower, and services, General Neuroscience, Brain interstitial division, Brain, Brain interstitial system, Anatomy, 03 medical and health sciences, 030104 developmental biology, health services administration, Brain size, In vivo measurement, Animals, Humans, Psychology, Extracellular Space, Biophysical modeling, human activities, Neuroscience
Abstract

Although neurons attract the most attention in neurobiology, our current knowledge of neural circuit can only partially explain the neurological and psychiatric conditions of the brain. Thus, it is also important to consider the influence of brain interstitial system (ISS), which refers to the space among neural cells and capillaries. The ISS is the major compartment of the brain microenvironment that provides the immediate accommodation space for neural cells, and it occupies 15% to 20% of the total brain volume. The brain ISS is a dynamic and complex space connecting the vascular system and neural networks and it plays crucial roles in substance transport and signal transmission among neurons. Investigation of the brain ISS can provide new perspectives for understanding brain architecture and function and for exploring new strategies to treat brain disorders. This review discussed the anatomy of the brain ISS under both physiological and pathological conditions, biophysical modeling of the brain ISS and in vivo measurement and imaging techniques, including recent findings on brain ISS divisions. Moreover, the implications of ISS knowledge for basic neuroscience and clinical applications are addressed.

Published
2015

106. A 3D Shape Reconstruction of Ligament from Arthroscopic Images

Author

Sakaguchi, Junpei, Katsuhara, Tadasuke, and Hirokawa, Shunji

Subjects
Arthroscopy, Shape from shading, In vivo measurement, musculoskeletal system, Anterior cruciate ligament, human activities
Abstract

In vivo data on the biomechanics of knee ligaments and their behavior under stress are necessary to understand and treat knee injuries. To obtain this data, accurate measurement of strains on and in the ligament is necessary. Technical and ethical considerations make such in vivo measurements of a human knee difficult or impossible. To overcome these problems, we planned to combine two techniques to measure stress/strain distributions; One is an arthroscopic measurement of ligament’s deformation. The other is to introduce stress/strain distributions using the deformation data through the FEM analysis. The objective of this study was to establish the method to obtain the 3D deformations from the arthroscopic images. The endoscopic photos were converted into grey scale images, and the shape from shading method was used to generate the objects' 3D shape from the images. Once the system was calibrated, a swine femur and tibia were set in a special fixture, and the industrial endoscope was used to pictures of the anterior cruciate ligament (ACL) at various angles of knee flexion. Three-dimensional coordinates were obtained by the level set method from the brightness data on the processed image and the three-dimensional shape of the ACL surface was generated.

Published
2006

108. Effect of UV radiation on the change of mechanical parameters of human skin

Author

Mazouchová, Denisa, Kuchařová, Monika, and Klemera, Petr

Subjects
Mechanical properties, UV radiation, in vivo measurement, in vivo měření, mechanické vlastnosti, UV záření
Abstract

Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Candidate: Denisa Mazouchová Supervizor: Mgr. Monika Kuchařová, Ph.D. Title of diploma thesis: Effect of ultraviolet radiation on the change the mechanical parameters of human skin This diploma thesis deals in theoretical part with the properties of human skin, the characteristics of the UV radiation and its effects on human skin. The practical part of the thesis focuses on the in vivo measurement of mechanical parameters of human skin after UV radiation. Mechanical characteristics of human skin were measured in 12 subjects before the application of UV radiation, immediately after application of UV and after 24 hours of rest skin. The experiment used a UV lamp with a wavelength of 370 nm emitted light. The monitored parameters were Hooke's and Newton's coefficients. Hooke's coefficient gives us the stiffness of the skin as a whole , Newton coefficient characterises its viscosity. For measurement of those parameters was used dynamic viscoelastomer. The experiment has been found out that no signifiant ganges of Hooke's and Newton's coefficients were not found immediately after the application of UV radiation of wavelength 370 nm, in 12 volunteers. Significant change occurred only in the...

Published
2014

109. [In vivo measurement of three-dimensional motion of the upper cervical spine using CT three-dimensional reconstruction].

Author

Zhai X, Kang J, Chen X, Dong J, Qiu XW, Ding XA, Liu J, and He XJ

Subjects
Adult, Aged, Biomechanical Phenomena, Cervical Vertebrae, Female, Humans, Male, Middle Aged, Range of Motion, Articular, Reproducibility of Results, Rotation, Spine, Tomography, X-Ray Computed, Young Adult, Atlanto-Axial Joint, Imaging, Three-Dimensional
Abstract

Objective: Using the CT three-dimensional reconstruction to measure the activity degree of atlanto-occipital joint and the atlantoaxial joint in different directions and its coupling movement in healthy volunteers, and three dimensional motion range of the maximum rotation position of the upper cervical spine of cervical spondylosis patients, and to analyze the differences, verifing the reliability of the method at the meantime., Methods: From January 2014 to June 2015, 20 healthy adult subjects(healthy adult group), and 26 patients with cervieal spondylosis(cervical spondylosis group) were selected. In healthy adult group, there were 11 males and 9 females, aged from 22 to 26 years old with an average of (24.0±1.2) years, and in cervical spondylosis group, there were 24 males and 2 females, aged from 36 to 72 years old with an average of (52.8±8.6) years. Healthy adults underwent CT examination in neutral position, maximum right rotation, maximum right lateral bending, maximum flexion and extention, and cervical spondylosis patients underwent CT examination in neutral position, maximum right rotation. Then the software Mimics was used to reconstruct occiput (Oc), atlas(C1) and axial(C2) vertebral three-dimensional image. Three virtual non-collinear markers were positioned on prominent structures of foramen magnum, C1 and C2. The 3D spatial coordinates of these virtual anatomical markers entail the definition of an anatomical local coordinate system which represent the position and orientation of the bones. Segmental motions were calculated using Eulerian angle in three major planes, and the difference between cervical spondylosis group and healthy adult group were compared. Due to the inaccuracy in anatomical landmark idenrification, two groups were measured 3 times, and the reliability of the experimental metnod was verified by the intra-group correlation (intra-group ICC) and the inter-group correlation coefficient(inter-group ICC)., Results: Reliability verification results:the intra-group ICC and inter-group ICC results were all above 0.90, and the measurement method had high reliability. Three-dimensional activity of the upper cervical spine in healthy adults:the atlanto-occipital joint had(-6.8±1.5)° coupled left lateral bending and (8.9±2.0)° coupled extension in the maximum right rotation position, and the motion of atlanto-occipital joint had low activity[maximum was(5.3±2.6)°] in the remaining 3 positions; the rotation of atlanto-axial joint was(37.9±5.1)°, accounting for 52.34% of the total cervical spine activity[(72.4±5.0)°] in the maximum right rotation position, and rotational motion was still prominent in the remaining three positions. The relative translations of the upper cervical spine in all direction were small. The average axial rotation angle [(62.0±3.4)] ° of the total cervical spine in cervical spondylosis group was significantly lower than that in the healthy adult group, but the mean axial rotation angles of the atlanto-occipital and the atlantoaxial joint were not significantly different from those of the healthy adults( P >0.05)., Conclusions: The three-dimensional CT reconstruction method has high reliability, which can be applied to measure the movement of spine. The upper cervical spine contributed the most to the direction of rotation, and the movement in all directions are accompanied by coupled motion in the other direction. There was no significant difference in the rotation of the upper cervical spine between cervical spondylosis patients and normal subjects., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© 2019 by the China Journal of Orthopaedics and Traumatology Press.)

Published
2019
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111. In vivo Messung der Schultergelenkbelastung mit Hilfe instrumentierter Endoprothesen

Author

Westerhoff, Peter, Kraft, Marc, and Technische Universität Berlin, Fakultät V - Verkehrs- und Maschinensysteme

Subjects
Shoulder, Gelenkbelastung, Implantat, Joint load, In vivo measurement, 620 Ingenieurwissenschaften und zugeordnete Tätigkeiten, Implant, In vivo Messung, ddc:620, Instrumentiert, Schulter, Instrumented
Abstract

In dieser Arbeit wurde die Belastung des Schultergelenkes mit Hilfe von instrumentierten Prothesen gemessen. Insgesamt wurden 8 dieser Implantate bei 8 Patienten eingesetzt. Durch die unterschiedlichen funktionellen Ergebnisse konnten allerdings nicht alle Patienten an allen Studien der verschiedenen Themengebiete teilnehmen. Insbesondere anspruchsvolle Übungen mit zusätzlichen Gewichten waren für einige Patienten nicht durchzuführen. Die Ergebnisse wurden in bisher 5 Publikationen in international anerkannten (peerreviewed) Zeitschriften veröffentlicht bzw. eingereicht und bilden die Grundlage der vorliegenden Arbeit. Die absolut größten Kräfte von mehr als 200% des Körpergewichtes (%BW) wurden gemessen bei körperlich sehr starken Patienten, die entweder ein externes Gewicht über den langen Helbelarm des ausgestreckten Armes hoben, oder aber willentlich eine maximale Muskelanspannung durchführten. Dabei war die Kraftrichtung trotz großer Bewegungsumfänge sehr konstant. Dies ist ein Aspekt, der auch schon bei Messungen an der Hüfte [1] und am Knie [2]beobachtet wurde. Ein Patient war sogar in der Lage, Liegestütze durchzuführen. Allerdings wurde bei dieser Übung der maximale Messbereich der Prothese durch eine Kombination von großer axialer Kraft (mehr als 240% des Körpergewichtes) und gleichzeitig großen wirkenden Biegemomenten (mehr als 9 Nm) überschritten. Die nicht unerheblichen Belastungen durch Biege- und Torsionsmomente wurden bisher in computergestützten Modellberechnungen nicht einkalkuliert und es zeigten sich individuell große Unterschiede zwischen den Patienten. Als ein grundlegendes Ergebnis zeigte sich, dass die Modellierung des Schultergelenkes als reibungsfreies Kugelgelenk den realen Bedingungen im prothetisch versorgten Schultergelenk nicht gerecht wird. Grund für die gemessenen Momente kann offensichtlich nicht nur in Reibung im Gelenk sein. Andernfalls müssten unwahrscheinlich hohe Reibungskoeffizienten bei einigen Patienten angenommen werden. Vielmehr erscheinen exzentrische Krafteinwirkung und/oder zusätzliche Kraftangriffspunkte z.B. am Acromion für die gemessenen Momente verantwortlich zu sein. Dies soll zukünftig mit zusätzlichen flouroskopischen Messungen untersucht werden. Ein weiterer zukünftiger Aspekt ist die Umrechnung der Belastungen auf das Glenoid mit Hilfe von simultaner Bewegungsanalyse. Erste Ergebnisse dieser Zusammenarbeit mit einer Forschungsgruppe aus den Niederlanden werden als Ausblick am Ende der Arbeit dargestellt., Content of this thesis is the in vivo measurement of shoulder joint contact loads. For this purpose an instrumented shoulder implant was developed. Eight of these devices were implanted in 8 patients. Because of the individual different functional outcome, not all patients could take part in all studies. The results of particulat topics are published or submitted as scientific papers to international peerreviewed journals. In general the highest should joint loads of more than 200 percentage of Bodyweight (%BW) were measured in strong and athletic patients with a good muscular constitution during maximum voluntary muscle contractions. Also high loads occurred whenever the patients moved the straight arm with an external weight and a long lever arm. The load direction during these high demanding tasks was very constant throughout the motion. Similar effects were also seen in studies measuring the hip [1] and knee joint load [2]. One patient was even able to do push-ups. Unfortunately the maximum measurement range of the implant was exceeded during this exercise with a combination of high axial forces (more than 240%BW) together with bending moments of more than 9Nm. Reason for the measured moments could be friction on the one hand, but also an eccentric shift of the resultant force caused by additional points of load application for example. These points could be the acromion or the processus coracoideus. In previous model calculations of shoulder joint loads, bending and torsional moments were mostly not taken into account at all. After measuring these moments in vivo, modeling of the shoulder joint as a frictionless ball and socket joint seems not to be appropriate, at least in case of a endoprosthetic replacement. To further investigate the reasons for the measured moments fluoroscopic measurements are planned for the future. However, the biggest issue regarding shoulder implants is still the glenoid component. Therefore, combined in vivo measurements and motion analysis were done with the group of Prof. Frans van der Helm in the Netherlands to convert the measured humeral loads on to the glenoid.

Published
2011
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112. Entwicklung eines instrumentierten Distraktionsmarknagels : Konzipierung der Methodik zur in vivo Messung der am Femur auftretenden Kräfte und Momente bei der Kallusdistraktion

Author

Glaser, Markus

Subjects
wireless energy transmission, Belastung [gnd], Implantat Belastungen, In vivo measurement, wireless data transmission, ddc:500, In vivo Messung, Kallusdistraktion [gnd], Energieübertragung [gnd], callus distraction, Implantat [gnd], Datenübertragung [gnd], implant load
Abstract

Einleitung:Trotz der sehr weiten Verbreitung von implantierbaren Prothesen, künstlichen Gelenken und Implantaten zur Frakturversorgung ist nur wenig gesichertes Wissen über die in vivo Belastung der Bauteile durch verschiedene Aktivitäten vorhanden. Ferner beruhen die wesentlichen Behandlungsparameter bei der Knochenverlängerung auf Arbeiten, die nunmehr bereits viele Jahre zurückliegen. Bei der Kallusdistraktion ist keine sichere Methode bekannt, um den Behandlungsverlauf zu evaluieren und gegebenenfalls korrigierend eingreifen zu können.Ziel:Ziel dieser Arbeit war, den Distraktionsmarknagel FITBONE® um eine Sensorik zur Axialkraft- und Biegemomentmessung zu erweitern, um die in vivo Belastungen des Implantats bei verschiedenen Aktivitäten messen zu können. Mit Hilfe des instrumentierten Distraktionsmarknagel und einer geeigneten Methodik, ist es dann möglich, die Kallusdistraktion hinsichtlich der Behandlungsparameter wie auch das Implantatdesign selbst zu optimieren.Methodik:Hierzu wurden die notwendigen Komponenten (Energie- und Datenübertragung, Sensorik, Elektronik und Mechanik) entwickelt und in das Implantat integriert. Das Gesamtsystem, bestehend aus einem externen Steuergerät und Implantat, wurde umfangreichen Tests unterzogen. Begleitend wurde ein Messaufbau mit weiteren Messgeräten (Kinematikanalysator, Kraftmessplatte, Sensorgehhilfen, EMG, Pedar-Sohlen) aufgebaut, vernetzt und getestet. Zur Erforschung der verschiedenen Fragestellungen wurde eine geeignete Methodik ausgehend von der Literaturrecherche und den Grenzen des Implantates konzipiert. Um die Messungen des instrumentierten Distraktionsmarknagels mit den Messungen von instrumentierten, externen Fixateuren aus der Literatur vergleichen zu können, wurde der Einfluss der Implantatsteifigkeit auf die Messergebnisse untersucht und die Konsequenzen zur Interpretation der Ergebnisse aufgezeigt.Ergebnis:Sämtliche Verifizierungstests wurden erfolgreich durchgeführt und abgeschlossen, so dass die Funktionsfähigkeit des Systems sichergestellt ist. Nach Abschluss der Sterilisationsvalidierung und Freigabe des Produktionsprozesses kann mit dem in vivo Einsatz des Systems und Durchführung der Messungen begonnen werden.Ausblick:Nach Abschluss und Auswertung der Messungen können die Erkenntnisse in die Software des Systems implementiert werden, um die Systemparameter automatisch dem individuellen Behandlungsverlauf anzupassen. Dieses System kann dann als intelligent bezeichnet werden. Mit dem intelligenten Distraktionsmarknagel-System wird dann eine zuverlässigere und optimierte Behandlung von Beinlängendifferenzen möglich sein.

Published
2010

113. Numerical efficiency calibration of in vivo measurement systems : Monte Carlo simulations of in vivo measurement scenarios for the detection of incorporated radionuclides, including validation, analysis of efficiency-sensitive parameters and customized anthropomorphic voxel models

Author

Hegenbart, Lars and Urban, M.

Subjects
in vivo measurement, voxel model, Monte Carlo radiation transport simulations, incorporated radionuclides, ddc:620, efficiency calibration, Engineering & allied operations
Abstract

Monte Carlo radiation transport codes were used with virtual models of in vivo measurement equipment. Software was coded to handle memory intensive anthropomorphic voxel models for simulation of measurement scenarios. Tools, methods and models have been validated. Various parameters have been investigated for their sensitivity. Methods based on image registration techniques have been developed to transform existing human models to match with an individual test person.

Published
2010

114. Numerical Efficiency Calibration of In Vivo Measurement Systems

Author

Hegenbart, Lars and Urban, M.

Subjects
In Vivo Measurement, Segmentation / Registration, Radiation Transport, ddc:620, Voxel Model, Monte Carlo Method, Engineering & allied operations
Abstract

Monte Carlo radiation transport codes were used with virtual models of in vivo measurement equipment. Software was coded to handle memory intensive anthropomorphic voxel models for simulations of measurement scenarios. Tools, methods, and models have been validated. Various parameters have been investigated for their sensitivity. Methods based on image registration techniques have been developed to transform existing human models to match with an individual test person.

Published
2009
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117. In vivo Prompt Gamma Neutron Activation Analysis Facility for Total Body Nitrogen and Cd.

Author

Munive, Marco, Solís, José L., and Revilla, Ángel

Subjects
*GAMMA functions, *TRANSCENDENTAL functions, *NUCLEAR activation analysis, *PARTICLES (Nuclear physics), *PHYSICAL measurements, *NITROGEN
Abstract

A Prompt Gamma Neutron Activation Analysis (PGNAA) system has been designed and constructed to measure the total body nitrogen and Cd for in vivo studies. An aqueous solution of KNO3 was used as phantom for system calibration. The facility has been used to monitor total body nitrogen (TBN) of mice and found that is related to their diet. Some mice swallowed diluted water with Cl2Cd, and the presence of Cd was detected in the animals. The minimum Cd concentration that the system can detect was 20 ppm. [ABSTRACT FROM AUTHOR]

Published
2007
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118. Measurement of lower-leg muscle impedance in national taekwondo team and students non-athletes

Author

Bursać, Danijel, Smoljkić, Gabrijel, Lacković, Igor, Rako, Duje, and Marković, Matija

Subjects
electrical bioimpedance, muscle impedance, in vivo measurement, taekwondo athletes, instrument control
Abstract

Electrical impedance is a complex measure of resistance, represented not only with relative magnitudes of voltage and current, but also with the phase angle. The phase angle represents the value of phase shift between the voltage and the current. We have measured the electrical impedance of musculus gastrocnemius for two different groups of examinees. The first group was Croatian taekwondo team with both males and females, and the other was a group of students matched on age and sex. The magnitude (|Z|) and phase (φ ) of impedance were measured from 100 Hz do 1 MHz, by the HP 4284A impedance meter, using the Ag-AgCl ECG self adhesive electrodes. To achieve easier control of the instrument parameters, we have developed a computer application using the Microsoft .NET 2.0 framework. The results show the difference of mean value of |Z| between taekwondo athletes and students at high frequencies. We have ignored the impedance at lower frequencies because it is dominantly affected by the electrode and skin impedance and does not reflect the difference of the impedance of muscles. We have found that the mean value of |Z| is lower for males and higher for females in both tested groups. We have compared the differences that we noticed, with the results of conductivity and permittivity measurements of Gabriel and co-workers. The measured differences in impedance spectra indicate the structural difference of the leg tissue between the groups. We think that the higher mean value of |Z| in females is probably because of genetically conditioned enlarged quantity of subdermal adipose tissue. The observed difference in impedance between male taekwondo team and the group of male students are most likely related to the larger muscle mass in members of the taekwondo team.

Published
2007

119. Application of a micro-multipoint laser doppler velocimeter for in vivo evaluation of subcutaneous blood flow.

Author

Akiguchi, Shunsuke, Ishida, Hiroki, Andoh, Tsugunobu, Shimizu, Tadamichi, Kuraishi, Yasushi, Yasuda, Yoshifumi, and Hachiga, Tadashi

Subjects
*LASER Doppler velocimeter, *MELANOMA diagnosis, *BLOOD vessels, *TISSUE fixation (Histology), *BLOOD flow
Abstract

We have developed a micro-multipoint laser Doppler velocimeter (µMLDV), which is the newest version of our improved laser Doppler velocimeter (LDV). This device can potentially be used clinically for the evaluation of the internal diameter of blood vessels, inspection of blood vessel protrusions and diagnosis of melanoma. To date, we have verified the accuracy of this device for three-dimensional measurement of blood vessels in vivo and measurement of melanoma. The state of blood flow is one of the evaluation criteria for tissue fixing. However, the state of blood flow is difficult to determine visually. If the state of blood flow can be visualized using this system, without damaging the affected area, it is possible to evaluate fixing noninvasively. Therefore, we measured normal blood vessels and cases in which there was no blood flow for comparison and verified the possibility of using the µMLDV as an evaluation device. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]

Published
2013
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120. [The simulative study of a new probe for the in vivo dielectric measurement of anisotropic tissue in radio frequency band].

Author

Zhang L, Zhang X, Zhou D, Li G, and Liu P

Abstract

In this paper, a new probe is proposed for the in vivo dielectric measurement of anisotropic tissue in radio frequency band, which could accomplish the dielectric measurement in perpendicular directions by one operation. The simulative studies are performed in the frequency range from 1-1 000 MHz in order to investigate the influence of probe dimension on the energy coupling and sensitivity of measurement. The suitable probe is designed and validated for the actual measurement in this frequency band. According to the simulation results, the energy coupling of the probe could be kept below -12 dB in the frequency range from 200-400 MHz with high sensitivity of measurement for the dielectric properties of anisotropic tissue. That indicates the new type of probe has the potential to achieve the dielectric measurement of anisotropic tissue in radio frequency band and could avoid the measurement error by multi-operations in the conventional method. This new type of probe could provide a new method for the in vivo dielectric measurement of anisotropic tissue in radio frequency band.

Published
2018
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121. Down to atomic-scale intracellular water dynamics

Author

Jasnin, M., Moulin, M., Haertlein, M., Zaccai, G., Tehei, M., Jasnin, M., Moulin, M., Haertlein, M., Zaccai, G., and Tehei, M.

Abstract

Water constitutes the intracellular matrix in which biological molecules interact. Understanding its dynamic state is a main scientific challenge, which continues to provoke controversy after more than 50 years of study. We measured water dynamics in vivo in the cytoplasm of Escherichia coli by using neutron scattering and isotope labelling. Experimental timescales covered motions from pure water to interfacial water, on an atomic length scale. In contrast to the widespread opinion that water is ‘tamed’ by macromolecular confinement, the measurements established that water diffusion within the bacteria is similar to that of pure water at physiological temperature.

Published
2008

123. Uptake and Exposure Measurements in Health Physics Technicians Associated with 131I-MIBG Patient Therapy

Author

Collier, Jason L.

Subjects
Mechanical Engineering, in vivo measurement, 131i-MIBG, health physics technician
Abstract

131 I-metaiodobenzylguanidine, 131 I-MIBG, has increasingly been used as an effective radiotherapeutic agent for pediatric patients diagnosed with neuroblastoma. While not a cure, the agent allows patients the possibility of controlling their disease and lengthening disease stabilization. Radioiodine pharmaceuticals were reformulated in 1979 to reduce exposure to those attending to the patient by reducing the volatility of the iodine and increasing the use of encapsulation to limit the quantity of unbound radioiodine. However, therapeutic 131 I-MIBG may still be administered to the patient through a liquid form. Health physics technicians are responsible for ensuring regulatory compliance and safety in and around the patient’s room. This study was performed to determine if the health physics technicians were exposed to 131 I while performing required tasks within the patient’s treatment room. Results showed that per therapeutic treatment, the health physics technicians were exposed to an average of 6.9x10-1 µSv hr-1GBq. Furthermore, trace contaminate levels of 131 I were detected by direct, in vivo measurement in persons having a normal and hypoactive thyroid. In vivo measurements were performed using a single 2900 mm 2 high resolution germanium detector positioned approximately 3 cm from the thyroid while the subject was seated in a shielded room. The thyroid activity measured in the technicians was well below requirements for monitoring established by the U.S. Nuclear Regulatory Commission. Established methods and working conditions are adequate to insure that radiation exposure to health physics technicians supporting the 131 I-MIBG radioiodine therapeutic procedures are consistent with the program to keep exposure as low as reasonably achievable.

Published
2016

124. Three-dimensional load on a tooth during function

Author

Yoda, N., Kawata, T., Kawaguchi, T., Suenaga, H., Kuriyagawa, T., and Sasaki, K.

Subjects
*TRANSDUCERS, *ELECTRIC equipment, *ELECTROMECHANICAL devices, *ELECTRONIC equipment
Abstract

Abstract: A load-measuring device comprised an inner part forming a metal core, a force transducer (Kistler Instrument AG), and an outer part forming a metal crown was developed and applied to a tooth for measuring functional load in vivo. The 3-D direction of the load on a tooth during clenching changed as the magnitude increased. It enabled time series measurement of the 3-D dynamic compressive and tractive load on a tooth, during functions in vivo, which might help to clarify the biomechanical characteristics of the stomatognathic system. [Copyright &y& Elsevier]

Published
2005
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125. In vivo and in situ measurement and modelling of intra-body effective complex permittivity.

Author

Nadimi ES, Blanes-Vidal V, Harslund JL, Ramezani MH, Kjeldsen J, Johansen PM, Thiel D, and Tarokh V

Abstract

Radio frequency tracking of medical micro-robots in minimally invasive medicine is usually investigated upon the assumption that the human body is a homogeneous propagation medium. In this Letter, the authors conducted various trial programs to measure and model the effective complex permittivity ε in terms of refraction ε', absorption ε″ and their variations in gastrointestinal (GI) tract organs (i.e. oesophagus, stomach, small intestine and large intestine) and the porcine abdominal wall under in vivo and in situ conditions. They further investigated the effects of irregular and unsynchronised contractions and simulated peristaltic movements of the GI tract organs inside the abdominal cavity and in the presence of the abdominal wall on the measurements and variations of ε' and ε''. They advanced the previous models of effective complex permittivity of a multilayer inhomogeneous medium, by estimating an analytical model that accounts for reflections between the layers and calculates the attenuation that the wave encounters as it traverses the GI tract and the abdominal wall. They observed that deviation from the specified nominal layer thicknesses due to non-geometric boundaries of GI tract morphometric variables has an impact on the performance of the authors' model. Therefore, they derived statistical-based models for ε' and ε'' using their experimental measurements.

Published
2015
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126. Influence of axial length on thickness measurements using spectral-domain optical coherence tomography.

Author

Röck T, Bartz-Schmidt KU, Bramkamp M, and Röck D

Subjects
Adult, Aged, Blindness physiopathology, Blindness surgery, Female, Follow-Up Studies, Humans, Male, Middle Aged, Retrospective Studies, Axial Length, Eye, Blindness pathology, Tomography, Optical Coherence methods, Visual Acuity, Visual Prosthesis
Abstract

Purpose: The purpose of this study was to assess the influence of axial length on spectral-domain optical coherence tomography (SD-OCT) thickness measurements in patients with subretinal visual implants., Methods: Data from eight emmetropic pseudophakic eyes of eight patients with subretinal visual implants were analyzed retrospectively. These patients participated in the monocentric part of a multicenter trial. The axial length was measured in three short (<22.5 mm), three medium (22.51-25.50 mm), and two long (>25.52 mm) eyes. Using Heidelberg Spectralis, the known thickness of a subretinal implant microchip (70 μm) was measured on 15 images per eye with SD-OCT, using the software calipers., Results: The mean axial length was 20.8 ± 0.8 mm in short eyes, 23.3 ± 0.4 mm in medium eyes, and 26.3 ± 0.5 mm in long eyes. We found in short eyes, in medium eyes, and in long eyes a mean value of microchip thickness measurements from SD-OCT of 82.9 ± 1.4 μm, 70.5 ± 1.3 μm, and 64.2 ± 1.3 μm, respectively. The thickness measurements decreased in SD-OCT measurements with longer axial lengths significantly (P < 0.0001)., Conclusions: Axial length influences SD-OCT thickness measurements. Our findings demonstrate accuracy of the scaling in SD-OCT thickness measurements in emmetropic medium eyes. Caution is recommended when comparing the measured values of short and long eyes with the normative database of the instrument. There is a need for larger sample-size studies to confirm our results. (ClinicalTrials.gov number, NCT01024803.)., (Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.)

Published
2014
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130. Low-frequency dielectric properties of the oral mucosa

Author

Zoran Stare, Igor Lacković, Scharfetter, Hermann, and Merwa, Robert

Subjects
Permittivity, impedance spectrum, in vivo measurement, FEM model, cell factor, probe sensitivity, Materials science, Optics, business.industry, LCR meter, Dispersion (optics), Dielectric, Low frequency, Conductivity, business, Penetration depth, Electrical impedance
Abstract

Low-frequency (≤ 1 MHz) electrical conductivity and permittivity spectra of the oral mucosa were reconstructed from impedance measurements at various regions (tongue, buccal mucosa, hard palate) of the oral cavity. Impedance magnitude and phase were measured with the HP4284A LCR meter in the frequency range from 30 Hz to 1 MHz. Bipolar intraoral measurement probe was used. In order to obtain conductivity and permittivity spectra from measured impedance data, the geometry factor of the probe (cell factor) was determined theoretically. Namely, numerical modeling using the finite-element method was used to calculate the geometry factor. The FEM model was also used to study the sensitivity field of the probe and the penetration depth. The results show typical dispersion characteristics observed in α -, and β -dispersion range of biological tissues. Possibilities of correcting electrode polarization, which causes error at lower frequencies are considered.

131. Study of penetration ratio using UWB antenna with an in vivo subject

Author

Benchakroun, H., Castelló-Palacios, S., Nevarez, A., Marta Cabedo Fabrés, and Ferrando-Bataller, M.

Subjects
in vivo measurement, penetration ratio, UWB antenna, propagation, macromolecular substances
Abstract

This paper presents a study of the penetration ratio through the human tissue for Body Area Network (BAN) applications of a compact antenna with directive behavior and wide impedance matching. The antenna is a coplanar UWB monopole covering the band from 2.8 GHz to 13.8 GHz. To analyze the penetration ratio of the antenna, two experiments using a phantom and an in vivo subject have been carried out. According to the experiments and the measured results, the antenna with enhanced radiation pattern and wide impedance matching, leads to a very good penetration into the human tissue. Measurements have been performed to demonstrate the validity of the simulated antenna performance through two experiments. The optimized UWB antenna displays a penetration ratio up to 17 cm in pure fat phantom and up to 16 cm in an in vivo subject, combined with a matching band of more than 10 GHz.

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