scholarly journals Controlled Measurement Setup for Ultra-Wideband Dielectric Modeling of Muscle Tissue in 20–45 ∘C Temperature Range

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7644
Author(s):  
Gertjan Maenhout ◽  
Tomislav Markovic ◽  
Bart Nauwelaers
Keyword(s):  
Dielectric Properties ◽  
Contact Pressure ◽  
Muscle Tissue ◽  
Ultra Wideband ◽  
Tissue Temperature ◽  
Dual Purpose ◽  
Dielectric Data ◽  
Dielectric Model ◽  
Cole Model

In order to design electromagnetic applicators for diagnostic and therapeutic applications, an adequate dielectric tissue model is required. In addition, tissue temperature will heavily influence the dielectric properties and the dielectric model should, thus, be extended to incorporate this temperature dependence. Thus, this work has a dual purpose. Given the influence of temperature, dehydration, and probe-to-tissue contact pressure on dielectric measurements, this work will initially present the first setup to actively control and monitor the temperature of the sample, the dehydration rate of the investigated sample, and the applied probe-to-tissue contact pressure. Secondly, this work measured the dielectric properties of porcine muscle in the 0.5–40 GHz frequency range for temperatures from 20 ∘C to 45 ∘C. Following measurements, a single-pole Cole–Cole model is presented, in which the five Cole–Cole parameters (ϵ∞, σs, Δϵ, τ, and α) are given by a first order polynomial as function of tissue temperature. The dielectric model closely agrees with the limited dielectric models known in literature for muscle tissue at 37 ∘C, which makes it suited for the design of in vivo applicators. Furthermore, the dielectric data at 41–45 ∘C is of great importance for the design of hyperthermia applicators.

scholarly journals Ultra-Wideband Temperature Dependent Dielectric Spectroscopy of Porcine Tissue and Blood in the Microwave Frequency Range

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1707 ◽  
Author(s):  
Sebastian Ley ◽  
Susanne Schilling ◽  
Ondrej Fiser ◽  
Jan Vrba ◽  
Jürgen Sachs ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Microwave Frequency ◽  
Ultra Wideband ◽  
Frequency Range ◽  
Temperature Dependent ◽  
Hyperthermia Treatment ◽  
Non Invasive ◽  
Animal Liver ◽  
Cole Model ◽  
Diagnostic Technologies

The knowledge of frequency and temperature dependent dielectric properties of tissue is essential to develop ultra-wideband diagnostic technologies, such as a non-invasive temperature monitoring system during hyperthermia treatment. To this end, we characterized the dielectric properties of animal liver, muscle, fat and blood in the microwave frequency range from 0.5 GHz to 7 GHz and in the temperature range between 30 °C and 50 °C. The measured data were modeled to a two-pole Cole-Cole model and a second-order polynomial was introduced to fit the Cole-Cole parameters as a function of temperature. The parametric model provides access to the dielectric properties of tissue at any frequency and temperature in the specified range.

Study on the influence of contact pressure on diffuse spectroscopy measurement of in vivo tissue

2021 ◽  
Vol 114 ◽  
pp. 103669
Author(s):  
Chenxi Li ◽  
Hua Xia ◽  
Yuning Zhou ◽  
Si Li ◽  
Rong Liu ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Spectroscopy Measurement

scholarly journals Evaluation of ultra-wideband in vivo radio channel and its effects on system performance

2018 ◽  
Vol 30 (1) ◽  
pp. e3530
Author(s):  
Muhammad Ilyas ◽  
Osman N. Ucan ◽  
Oguz Bayat ◽  
Ali Arshad Nasir ◽  
Muhammad Ali Imran ◽  
...  
Keyword(s):  
System Performance ◽  
Radio Channel ◽  
Ultra Wideband

Molecular characterization of the in vivo effects of the hemorrhagic metalloproteinase HF3: analysis of the proteome of mice muscle tissue

Toxicon ◽  
2019 ◽  
Vol 168 ◽  
pp. S21
Author(s):  
Eric Junqueira Brito Pereira ◽  
Dilza Trevisan Silva ◽  
Solange Maria De Toledo Serrano
Keyword(s):  
Molecular Characterization ◽  
Muscle Tissue ◽  
In Vivo Effects

scholarly journals Metformin Delays Satellite Cell Activation and Maintains Quiescence

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Theodora Pavlidou ◽  
Milica Marinkovic ◽  
Marco Rosina ◽  
Claudia Fuoco ◽  
Simone Vumbaca ◽  
...  
Keyword(s):  
Satellite Cell ◽  
Muscle Tissue ◽  
Satellite Cells ◽  
Cell Activation ◽  
Myogenic Differentiation ◽  
Metabolic State ◽  
Cell Pool ◽  
Age Related ◽  
Satellite Cell Activation

The regeneration of the muscle tissue relies on the capacity of the satellite stem cell (SC) population to exit quiescence, divide asymmetrically, proliferate, and differentiate. In age-related muscle atrophy (sarcopenia) and several dystrophies, regeneration cannot compensate for the loss of muscle tissue. These disorders are associated with the depletion of the satellite cell pool or with the loss of satellite cell functionality. Recently, the establishment and maintenance of quiescence in satellite cells have been linked to their metabolic state. In this work, we aimed to modulate metabolism in order to preserve the satellite cell pool. We made use of metformin, a calorie restriction mimicking drug, to ask whether metformin has an effect on quiescence, proliferation, and differentiation of satellite cells. We report that satellite cells, when treated with metformin in vitro, ex vivo, or in vivo, delay activation, Pax7 downregulation, and terminal myogenic differentiation. We correlate the metformin-induced delay in satellite cell activation with the inhibition of the ribosome protein RPS6, one of the downstream effectors of the mTOR pathway. Moreover, in vivo administration of metformin induces a belated regeneration of cardiotoxin- (CTX-) damaged skeletal muscle. Interestingly, satellite cells treated with metformin immediately after isolation are smaller in size and exhibit reduced pyronin Y levels, which suggests that metformin-treated satellite cells are transcriptionally less active. Thus, our study suggests that metformin delays satellite cell activation and differentiation by favoring a quiescent, low metabolic state.

scholarly journals Toward Development of a Vocal Fold Contact Pressure Probe: Sensor Characterization and Validation Using Synthetic Vocal Fold Models

2019 ◽  
Vol 9 (15) ◽  
pp. 3002 ◽  
Author(s):  
Mohsen Motie-Shirazi ◽  
Matías Zañartu ◽  
Sean D. Peterson ◽  
Daryush D. Mehta ◽  
James B. Kobler ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Vocal Fold ◽  
Ground Truth ◽  
Pressure Probe ◽  
Primary Role ◽  
Novel Approach ◽  
Sensor Position ◽  
Probe Sensor ◽  
Contact Pressures

Excessive vocal fold collision pressures during phonation are considered to play a primary role in the formation of benign vocal fold lesions, such as nodules. The ability to accurately and reliably acquire intraglottal pressure has the potential to provide unique insights into the pathophysiology of phonotrauma. Difficulties arise, however, in directly measuring vocal fold contact pressures due to physical intrusion from the sensor that may disrupt the contact mechanics, as well as difficulty in determining probe/sensor position relative to the contact location. These issues are quantified and addressed through the implementation of a novel approach for identifying the timing and location of vocal fold contact, and measuring intraglottal and vocal fold contact pressures via a pressure probe embedded in the wall of a hemi-laryngeal flow facility. The accuracy and sensitivity of the pressure measurements are validated against ground truth values. Application to in vivo approaches are assessed by acquiring intraglottal and VF contact pressures using a synthetic, self-oscillating vocal fold model in a hemi-laryngeal configuration, where the sensitivity of the measured intraglottal and vocal fold contact pressure relative to the sensor position is explored.

Tissue Temperature Transients in Resting Contra-Lateral Leg Muscle Tissue During Isolated Knee Extension

2002 ◽  
Vol 27 (6) ◽  
pp. 535-550 ◽  
Author(s):  
Glen P. Kenny ◽  
Frank D. Reardon ◽  
Michel B. Ducharme ◽  
Mark L. Reardon ◽  
Wytek Zaleski
Keyword(s):  
Core Temperature ◽  
Muscle Tissue ◽  
Muscle Activity ◽  
Maximal Oxygen Consumption ◽  
Knee Extension ◽  
Tissue Temperature ◽  
Dynamic Resistance ◽  
Force Output ◽  
Sensor Temperature ◽  
Internal Marker

This study was designed to evaluate the role of non-active tissue in the retention and dissipation of heat during and following intense isolated muscle activity. Six subjects performed an incremental isotonic test (constant angular velocity, increases in force output) on a KIN-COM' isokinetic apparatus to determine their maximal oxygen consumption during single knee extensions [Formula: see text] In a subsequent session, a thin wire multi-sensor temperature probe was inserted into the left vastus medialis under ultrasound guidance at a specific internal marker. The deepest temperature sensor (tip, Tmu10) was located ∼10 mm from the femur and deep femoral artery with 2 additional sensors located at 15 (Tmu25) and 30 (Tmu40) mm from the tip. Implant site was midway between and medial to a line joining the anterior superior iliac spine and base of patella. Esophageal temperature (Tes) temperature was measured as an index of core temperature. Subjects rested in a supine position for 60 min followed by 30 min of seated rest in an ambient condition of 22 °C. Subjects then performed 15 min of isolated single right knee extensions against a dynamic resistance on a KIN COM corresponding to 60% of [Formula: see text] at 60° • sec−1. Exercise was followed by 60 min of seated rest. Resting Tes was 37 °C while Tmu10, Tmu25, and Tmu40 were 36.58, 36.55 and 36.45 °C, respectively. Exercise resulted in a Tes increase of 0.31 °C above pre-exercise resting. Tmu of the non-exercising leg increased 0.23, 0.19 and 0.09 °C for Tmu10, Tmu25, and Tmu40, respectively. While Tes decreased to baseline values within ∼15 min of end-exercise, Tmu10 reached resting values following ∼40 min of recovery. These results suggest that during isolated muscle activity, convective heat transfer by the blood to non-active muscle tissue may have a significant role in maintaining resting core temperature. Key words: heat load, thermoregulation, hyperthermia

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