scholarly journals A Microelectrode Array for Real-Time Neurochemical and Neuroelectrical Recording In Vitro

2000 ◽  
Author(s):  
T. Strong ◽  
H.C. Cantor ◽  
R.B. Brown
Keyword(s):  
Real Time ◽  
Microelectrode Array

A microelectrode array for real-time neurochemical and neuroelectrical recording in vitro

2001 ◽  
Vol 91 (3) ◽  
pp. 357-362 ◽  
Author(s):  
Timothy D. Strong ◽  
Hal C. Cantor ◽  
Richard B. Brown
Keyword(s):  
Real Time ◽  
Microelectrode Array

scholarly journals Real-Time Analysis of Oxygen Gradient in Oocyte Respiration Using a High-Density Microelectrode Array

Biosensors ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 256
Author(s):  
William Tedjo ◽  
Yusra Obeidat ◽  
Giovana Catandi ◽  
Elaine Carnevale ◽  
Tomas Chen
Keyword(s):  
Real Time ◽  
Oxygen Concentration ◽  
Microelectrode Array ◽  
Temporal Dynamics ◽  
Imaging System ◽  
High Density ◽  
Oxide Semiconductor ◽  
Two Dimensional ◽  
Imaging Results

Physiological events related to oxygen concentration gradients provide valuable information to determine the state of metabolizing biological cells. The existing oxygen sensing methods (i.e., optical photoluminescence, magnetic resonance, and scanning electrochemical) are well-established and optimized for existing in vitro analyses. However, such methods also present various limitations in resolution, real-time sensing performance, complexity, and costs. An electrochemical imaging system with an integrated microelectrode array (MEA) would offer attractive means of measuring oxygen consumption rate (OCR) based on the cell’s two-dimensional (2D) oxygen concentration gradient. This paper presents an application of an electrochemical sensor platform with a custom-designed complementary-metal-oxide-semiconductor (CMOS)-based microchip and its Pt-coated surface MEA. The high-density MEA provides 16,064 individual electrochemical pixels that cover a 3.6 mm × 3.6 mm area. Utilizing the three-electrode configuration, the system is capable of imaging low oxygen concentration (18.3 µM, 0.58 mg/L, or 13.8 mmHg) at 27.5 µm spatial resolution and up to 4 Hz temporal resolution. In vitro oxygen imaging experiments were performed to analyze bovine cumulus-oocytes-complexes cells OCR and oxygen flux density. The integration of a microfluidic system allows proper bio-sample handling and delivery to the MEA surface for imaging. Finally, the imaging results are processed and presented as two-dimensional (2D) heatmaps, representing the dissolved oxygen concentration in the immediate proximity of the MEA. This paper provides the results of real-time 2D imaging of OCR of live cells/tissues to gain spatial and temporal dynamics of target cell metabolism.

scholarly journals Development and Validation of a Spike Detection and Classification Algorithm Aimed at Implementation on Hardware Devices

2010 ◽  
Vol 2010 ◽  
pp. 1-15 ◽  
Author(s):  
E. Biffi ◽  
D. Ghezzi ◽  
A. Pedrocchi ◽  
G. Ferrigno
Keyword(s):  
Real Time ◽  
Data Storage ◽  
Microelectrode Array ◽  
Transmission Rate ◽  
Waveform Analysis ◽  
Spike Detection ◽  
Real Signal ◽  
Real Time Analysis ◽  
On Line

Neurons cultured in vitro on MicroElectrode Array (MEA) devices connect to each other, forming a network. To study electrophysiological activity and long term plasticity effects, long period recording and spike sorter methods are needed. Therefore, on-line and real time analysis, optimization of memory use and data transmission rate improvement become necessary. We developed an algorithm for amplitude-threshold spikes detection, whose performances were verified with (a) statistical analysis on both simulated and real signal and (b) Big O Notation. Moreover, we developed a PCA-hierarchical classifier, evaluated on simulated and real signal. Finally we proposed a spike detection hardware design on FPGA, whose feasibility was verified in terms of CLBs number, memory occupation and temporal requirements; once realized, it will be able to execute on-line detection and real time waveform analysis, reducing data storage problems.

scholarly journals Real-time monitoring of liver fibrosis through embedded sensors in a microphysiological system

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Hafiz Muhammad Umer Farooqi ◽  
Bohye Kang ◽  
Muhammad Asad Ullah Khalid ◽  
Abdul Rahim Chethikkattuveli Salih ◽  
Kinam Hyun ◽  
...  
Keyword(s):  
Cell Culture ◽  
Liver Fibrosis ◽  
Real Time ◽  
Hepatic Fibrosis ◽  
Transforming Growth Factor ◽  
Cell Monolayer ◽  
Embedded Sensors ◽  
Matrix Deposition ◽  
Tgf Β1

AbstractHepatic fibrosis is a foreshadowing of future adverse events like liver cirrhosis, liver failure, and cancer. Hepatic stellate cell activation is the main event of liver fibrosis, which results in excessive extracellular matrix deposition and hepatic parenchyma's disintegration. Several biochemical and molecular assays have been introduced for in vitro study of the hepatic fibrosis progression. However, they do not forecast real-time events happening to the in vitro models. Trans-epithelial electrical resistance (TEER) is used in cell culture science to measure cell monolayer barrier integrity. Herein, we explored TEER measurement's utility for monitoring fibrosis development in a dynamic cell culture microphysiological system. Immortal HepG2 cells and fibroblasts were co-cultured, and transforming growth factor β1 (TGF-β1) was used as a fibrosis stimulus to create a liver fibrosis-on-chip model. A glass chip-based embedded TEER and reactive oxygen species (ROS) sensors were employed to gauge the effect of TGF-β1 within the microphysiological system, which promotes a positive feedback response in fibrosis development. Furthermore, albumin, Urea, CYP450 measurements, and immunofluorescent microscopy were performed to correlate the following data with embedded sensors responses. We found that chip embedded electrochemical sensors could be used as a potential substitute for conventional end-point assays for studying fibrosis in microphysiological systems.

Real-time quantitative monitoring of in vitro nasal drug delivery by a nasal epithelial mucosa-on-a-chip model

2021 ◽  
Author(s):  
Hanieh Gholizadeh ◽  
Hui Xin Ong ◽  
Peta Bradbury ◽  
Agisilaos Kourmatzis ◽  
Daniela Traini ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Real Time ◽  
Nasal Drug Delivery ◽  
Quantitative Monitoring

scholarly journals A “Smart” Biosensor-Enabled Intravascular Catheter and Platform for Dynamic Delivery of Propofol to “Close the Loop” for Total Intravenous Anesthesia

2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 370-377
Author(s):  
Edward Chaum ◽  
Ernő Lindner
Keyword(s):  
Real Time ◽  
Drug Distribution ◽  
Population Based ◽  
Pharmacokinetic Data ◽  
Drug Infusion ◽  
Blood Concentrations ◽  
The Usa ◽  
The Difference ◽  
Automated Delivery

ABSTRACT Background Target-controlled infusion anesthesia is used worldwide to provide user-defined, stable, blood concentrations of propofol for sedation and anesthesia. The drug infusion is controlled by a microprocessor that uses population-based pharmacokinetic data and patient biometrics to estimate the required infusion rate to replace losses from the blood compartment due to drug distribution and metabolism. The objective of the research was to develop and validate a method to detect and quantify propofol levels in the blood, to improve the safety of propofol use, and to demonstrate a pathway for regulatory approval for its use in the USA. Methods We conceptualized and prototyped a novel “smart” biosensor-enabled intravenous catheter capable of quantifying propofol at physiologic levels in the blood, in real time. The clinical embodiment of the platform is comprised of a “smart” biosensor-enabled catheter prototype, a signal generation/detection readout display, and a driving electronics software. The biosensor was validated in vitro using a variety of electrochemical methods in both static and flow systems with biofluids, including blood. Results We present data demonstrating the experimental detection and quantification of propofol at sub-micromolar concentrations using this biosensor and method. Detection of the drug is rapid and stable with negligible biofouling due to the sensor coating. It shows a linear correlation with mass spectroscopy methods. An intuitive graphical user interface was developed to: (1) detect and quantify the propofol sensor signal, (2) determine the difference between targeted and actual propofol concentration, (3) communicate the variance in real time, and (4) use the output of the controller to drive drug delivery from an in-line syringe pump. The automated delivery and maintenance of propofol levels was demonstrated in a modeled benchtop “patient” applying the known pharmacokinetics of the drug using published algorithms. Conclusions We present a proof-of-concept and in vitro validation of accurate electrochemical quantification of propofol directly from the blood and the design and prototyping of a “smart,” indwelling, biosensor-enabled catheter and demonstrate feedback hardware and software architecture permitting accurate measurement of propofol in blood in real time. The controller platform is shown to permit autonomous, “closed-loop” delivery of the drug and maintenance of user-defined propofol levels in a dynamic flow model.

Human Umbilical Cord Mesenchymal Stem Cells Induce into Chondrocytes in 3D Cultured System

2013 ◽  
Vol 749 ◽  
pp. 198-205
Author(s):  
Li Yu ◽  
Jing Liu ◽  
Chao Xu ◽  
Er Mei Luo ◽  
Ming Qiao Tang
Keyword(s):  
Real Time ◽  
Alcian Blue ◽  
Culture System ◽  
Type Ii Collagen ◽  
Human Umbilical Cord ◽  
Type Ii ◽  
Pellet Culture ◽  
Hla Dr

Objective: To investigate a better method of inducing hUC-MSCs into chondrocytes in different culture system in vitro. Method: hUC-MSCs were isolated and cultured by tissue block culture, and the cells surface antigens were identified by flow cytometry, hUC-MSCs were cultured with chondrogenic media and stained with Alcian Blue. The production of matrix was estimated from the determination of hydroxyproline content and Alcian Blue method. Expressions of glycosaminoglycan (GAG), type II collagen and Sox-9 were assayed by real-time fluorescence quantitative PCR. Results: The cultured hUC-MSCs phenotype was CD105+/CD29+/CD44+/ CD31-/CD34-/ CD40-/CD45-/HLA-DR-. hUC-MSCs weakly expressed chondrocyte marker, which strongly expressed GAG and type II collagen after chondrogenic induction, and the cells were incubated in pellet culture with higher expression. Real-time PCR results demonstrated that chondrogenic induction cells were expressed GAG, type II collagen and Sox-9, and the cells were incubated in pellet culture with higher expression. Conclusion: hUC-MSCs incubated in pellet culture is more conducive to differentiate into chondrocytes than those cultured in monolayer culture system.

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