Non-invasive Urine Volume Estimation in the Bladder by Electrical Impedance-Based Methods: A Review

2021 ◽  
pp. 103748
Author(s):  
Shuhei S Noyori ◽  
Gojiro Nakagami ◽  
Hiromi Sanada
Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2231 ◽  
Author(s):  
Sarah Tonello ◽  
Andrea Bianchetti ◽  
Simona Braga ◽  
Camillo Almici ◽  
Mirella Marini ◽  
...  

One of the main hurdles to improving scaffolds for regenerative medicine is the development of non-invasive methods to monitor cell proliferation within three-dimensional environments. Recently, an electrical impedance-based approach has been identified as promising for three-dimensional proliferation assays. A low-cost impedance-based solution, easily integrable with multi-well plates, is here presented. Sensors were developed using biocompatible carbon-based ink on foldable polyimide substrates by means of a novel aerosol jet printing technique. The setup was tested to monitor the proliferation of human mesenchymal stromal cells into previously validated gelatin-chitosan hybrid hydrogel scaffolds. Reliability of the methodology was assessed comparing variations of the electrical impedance parameters with the outcomes of enzymatic proliferation assay. Results obtained showed a magnitude increase and a phase angle decrease at 4 kHz (maximum of 2.5 kΩ and −9 degrees) and an exponential increase of the modeled resistance and capacitance components due to the cell proliferation (maximum of 1.5 kΩ and 200 nF). A statistically significant relationship with enzymatic assay outcomes could be detected for both phase angle and electric model parameters. Overall, these findings support the potentiality of this non-invasive approach for continuous monitoring of scaffold-based cultures, being also promising in the perspective of optimizing the scaffold-culture system.


2019 ◽  
Vol 91 (9) ◽  
pp. 1481-1491 ◽  
Author(s):  
Leszek Kubisz ◽  
Dorota Hojan-Jezierska ◽  
Maria Szewczyk ◽  
Anna Majewska ◽  
Weronika Kawałkiewicz ◽  
...  

Abstract Structural and chemical alterations in living tissue are reflected in electrical impedance changes. However, due to the complexity of skin structure, the relation between electrical parameters and physiological/pathological conditions is difficult to establish. The impedance dispersion reflects the clinical status of the examined skin tissue and, therefore, it is frequently used in a non-invasive evaluation of exposing skin to various factors. The method has been used to assess the effect of the fish collagen on the skin of patients suffering from the leg ulcer. Therefore, from a number of different approaches to skin electrical impedance dispersion, the one considered to be safe was selected and applied. This paper presents a short review of different technical approaches to in vivo electrical impedance measurements, as well as an analysis of the results and the effect of fish collagen locally administered on human skin.


1995 ◽  
Vol 1995 ◽  
pp. 18-18
Author(s):  
K.J. Shingfield ◽  
N.W. Offer ◽  
A.M. Sword

The urinary excretion of purine derivatives has been proposed as a non-invasive method of estimating the outflow of rumen microbial protein. Wider application of this technique is hindered by the requirement for a total urine collection, but Chen et al. (1992) suggested the use of urinary Creatinine(C) concentration to account for changes in urine volume. The relative concentrations of Purine Derivatives (PD) and C in spot urine samples could be used as a suitable index of PD output. The following experiment assesses the validity of this approach in lactating Holstein/Friesan cattle.


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