Search Results

1 - 10 of 227 items :

  • "Measurement" x
  • Biomedical Engineering x
Clear All
Finite difference model of a four-electrode conductivity measurement system

Introduction Four electrode measurement (4EM) systems have been used to measure conductivity in tissue where electrode polarization would cause unacceptable inaccuracy in measurement results and where directional measurement of conductivity is required Less polarization than a two-electrode measurement system where the current is applied by the same electrodes that measures the potential and directional measurement as opposed to a coaxial measurement system that measures bulk conductivity but gives no information about direction. ( 1 , 2 , 3) . The system

Open access
Applications of bioimpedance measurement techniques in tissue engineering

the tissue engineered constructs. However, these methods such as histology staining, are destructive and time-consuming and require fixing and cutting the tissue cultures ( 6 ). Therefore, there is a need for real-time and noninvasive monitoring techniques to evaluate the quality of the tissue engineered constructs before implanting them in the body, without the need to use fluorescents or radioactive labels or destructive methods. This in addition, would reduce the number of animals required for this purpose ( 5 , 6 ). Bioimpedance Measurements Basics of

Open access
Biomass measurement of living Lumbriculus variegatus with impedance spectroscopy

as a static capacitor. The dielectric properties of biological cells and their different components (cell wall, membranes and cytoplasm) were summarized by Markx and Davey [ 4 ]. Over the last couple of decades a lot of research was done on the impedance of cell suspensions, in which a relationship between capacitance and viable cell number was reported [ 5 , 6 , 7 , 8 ]. Fehrenbach et al. [ 5 ] used online capacitive measurements for biomass estimation of Saccaromyces cerevisiae , Pitchia pastoris and Streptomyces virginiae in suspension culture. In their

Open access
Analysis of the measurement uncertainty during calibration of radioherapy and radiodiagnostics dosemeters at the Polish Secondary Standard Dosimetry Laboratory

Reports Series, Vienna, 2000; No TRS 398. IAEA. Calibration of reference dosimeters for external beam radiotherapy. Technical Reports Series, Vienna, 2009; No TRS 469. IAEA. Dosimetry in diagnostic radiology. An international code of practice. Technical Reports Series, Vienna, 2007; No TRS 457. ISO/IEC/OIML/BIPM, Guide to the expression of uncertainty in measurements. 1995.

Open access
Automated MTF measurement in CT images with a simple wire phantom

References [1] Verdun FR, Racine D, Ott JG, et al. Image quality in CT: From physical measurements to model observers. Phys Med. 2015;31(8):823-843. [2] International Atomic Energy Agency. Status of computed tomography: Dosimetry for wide cone beam scanners. IAEA-Human Health Reports No 5. 2011. [3] Kalender WA, Seissler W, Klotz E, Vock P. Spiral volumetric CT with single-breath-hold technique, continuous transport, and continuous scanner rotation. Radiology. 1990;176(1):181-183. [4] McCollough CH, Zink FE. Performance evaluation of a

Open access
The effect of heart pulsatile on the measurement of artery bioimpedance

Introduction Bioimpedance is a widely used technique to measure the body composition due to its various advantages such as noninvasiveness, accuracy, applicability and low cost [ 1 ]. The measurement of artery bioimpedance is proposed in this study because it is used to diagnose numerous of blood diseases such as the cholesterol level, the foundation of stenosis, and diabetes [ 1 ]. Furthermore, the studying of the heart pulsatile effect may be used to measure the heart rate as a novel method for heart rate detection based on bioimpedance phenomena. The heart

Open access
Simulation of impedance measurements at human forearm within 1 kHz to 2 MHz

which is an invasive method and cannot readily measure beat-to-beat changes. Electrical impedance measurements at the forearm provide a possible way to characterize hemodynamics, and in particular changes in the amount of blood in the arm as a result of vasodilatation and/or the cardiac cycle. Although the simulation perspective to bioimpedance plethysmography is a rarity there have been several investigations pertaining to the impedance response at forearm section. Some works [ 13 , 14 , 15 , 16 ] related to multi-frequency electrical bioimpedance (MF-EBI) for

Open access
Diffuse reflectance spectroscopy for identification of carcinogen transformation stages in skin tissue


Today, to establish a diagnosis, the patient must undergo a biopsy followed by histopathological diagnosis, which causes unnecessary cost, patient trauma, and time delay to obtain a diagnosis. However, the metastases can be discovered by diffuse reflectance spectroscopy, which is a simple method that investigates the light distribution within tissue. The theme of this paper is the use of diffuse reflectance spectroscopy (DRS) to determine the optical spectrum of hamster specimen’s tissue and to differentiate biological changes due to laser irradiation (scattering, and cell changes) under the skin. DRS measurements were made on healthy and malignant tissue to diagnose the stages of cancer formation using a fiber-optic probe. The results show that malignant tissue is characterized by a significant decrease in diffuse reflectance spectrum compared to normal tissue.

Open access
SIMU-RAD programme: a learning tool for radiation (photons and charged particles) interaction

-Contacting System to Online Measure the Radiotracer Concentration in Blood. Prog Nucl Sci Technol. 2014;4:290-293. [13] Hubbell JH, Seltzer SM. X-Ray Mass Attenuation Coefficients. NISTIR 5632. . [14] Berger MJ, Hubbell JH, Seltzer SM, et al. XCOM: Photon Cross Sections Database. NBSIR 87-3597. . [15] Pawar PP. Measurement of Mass and Linear Attenuation Coefficients of Gamma-Rays of AL for 514, 662 and 1280 keV Photons. J Chem Pharm Res. 2011;3(4): 899

Open access
Dosimetric comparison of jaw tracking in intensity modulated and volumetric modulated arc radiotherapy for carcinoma of cervix

of the uterine cervix. Int J Radiat Oncol Biol Phys. 1995;32(5):1289-1300, [4] Hasselle MD, Rose BS, Kochanski JD, et al. Clinical Outcomes of Intensity-Modulated Pelvic Radiation Therapy for Carcinoma of the Cervix. Int J Radiat Oncol Biol Phys. 2011;80(5):1436-1445. [5] Ng J, Shuryak I. Minimizing second cancer risk following radiotherapy: current perspectives. Cancer Manag Res 2014; 7 :1-11. [6] International Commission on Radiation Units and Measurements. Prescribing, recording, and reporting photon beam intensity-modulated radiation therapy

Open access