scholarly journals Development of a Smartphone-Based Fluorescent Immunochromatographic Assay Strip Reader

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4521
Author(s):  
Qi Zheng ◽  
Huihuang Wu ◽  
Haiyan Jiang ◽  
Jiejie Yang ◽  
Yueming Gao
Keyword(s):  
High Precision ◽  
Relative Error ◽  
Image Sensors ◽  
Immunochromatographic Assay ◽  
Maximum Relative Error ◽  
Excitation Light ◽  
Detection Range ◽  
Cmos Image Sensors ◽  
Linear Detection ◽  
Optical Module

Fluorescence immunochromatographic assay (FICA) is a rapid immunoassay technique that has the characteristics of high precision and sensitivity. Although image FICA strip readers have the advantages of high portability and easy operation, the use of high-precision complementary metal oxide semiconductor (CMOS) image sensors leads to an increase in overall cost. Considering the popularity of CMOS image sensors in smartphones and their powerful processing functions, this work developed a smartphone-based FICA strip reader. An optical module suitable for the test strips with different fluorescent markers was designed by replacing the excitation light source and the light filter. An android smartphone was used for image acquisition and image denoising. Then, the test and control lines of the test strip image were recognized by the sliding window algorithm. Finally, the characteristic value of the strip image was calculated. A linear detection range from 10 to 5000 mIU/mL (R2 = 0.95) was obtained for human chorionic gonadotrophin with the maximum relative error less than 9.41%, and a linear detection range from 5 to 4000 pg/mL (R2 = 0.99) was obtained for aflatoxin B1, with the maximum relative error less than 12.71%. Therefore, the smartphone-based FICA strip reader had high portability, versatility, and accuracy.

scholarly journals Low-Latency and Minor-Error Architecture for Parallel Computing XY-Like Functions with High-Precision Floating-Point Inputs

Electronics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 69
Author(s):  
Ming Liu ◽  
Wenjia Fu ◽  
Jincheng Xia
Keyword(s):  
High Precision ◽  
Relative Error ◽  
State Of The Art ◽  
Latency Period ◽  
Limited Range ◽  
The State ◽  
Floating Point ◽  
Cordic Algorithm ◽  
Maximum Relative Error ◽  
Large Area

This paper proposes a novel architecture for the computation of XY-like functions based on the QH CORDIC (Quadruple-Step-Ahead Hyperbolic Coordinate Rotation Digital Computer) methodology. The proposed architecture converts direct computing of function XY to logarithm, multiplication, and exponent operations. The QH CORDIC methodology is a parallel variant of the traditional CORDIC algorithm. Traditional CORDIC suffers from long latency and large area, while the QH CORDIC has much lower latency. The computation of functions lnx and ex is accomplished with the QH CORDIC. To solve the problem of the limited range of convergence of the QH CORDIC, this paper employs two specific techniques to enlarge the range of convergence for functions lnx and ex, making it possible to deal with high-precision floating-point inputs. Hardware modeling of function XY using the QH CORDIC is plotted in this paper. Under the TSMC 65 nm standard cell library, this paper designs and synthesizes a reference circuit. The ASIC implementation results show that the proposed architecture has 30 more orders of magnitude of maximum relative error and average relative error than the state-of-the-art. On top of that, the proposed architecture is also superior to the state-of-the-art in terms of latency, word length and energy efficiency (power × latency × period /efficient bits).

scholarly journals Automatic Range Adjustment of the Fluorescence Immunochromatographic Assay Based on Image Processing

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 209 ◽  
Author(s):  
Ruixin Jiang ◽  
Huihuang Wu ◽  
Jianpeng Yang ◽  
Haiyan Jiang ◽  
Min Du ◽  
...  
Keyword(s):  
Image Processing ◽  
Point Of Care ◽  
Strong Stability ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Image Sensors ◽  
Oxide Semiconductor ◽  
Detection Sensitivity ◽  
Immunochromatographic Assay ◽  
Detection Range

As an emerging technology, fluorescence immunochromatographic assay (FICA) has the advantages of high sensitivity, strong stability and specificity, which is widely used in the fields of medical testing, food safety and environmental monitoring. The FICA reader based on image processing meets the needs of point-of-care testing because of its simple operation, portability and fast detection speed. However, the image gray level of common image sensors limits the detection range of the FICA reader, and high-precision image sensors are expensive, which is not conducive to the popularization of the instrument. In this paper, FICA strips’ image was collected using a common complementary metal oxide semiconductor (CMOS) image sensor and a range adjustment mechanism was established to automatically adjust the exposure time of the CMOS image sensor to achieve the effect of range expansion. The detection sensitivity showed a onefold increase, and the upper detection limit showed a twofold increase after the proposed method was implemented. In addition, in the experiments of linearity and accuracy, the fitting degree (R2) of the fitted curves both reached 0.999. Therefore, the automatic range adjustment method can obviously improve the detection range of the FICA reader based on image processing.

Error-aware Design Procedure to Implement Energy-efficient Approximate Squaring Hardware

2020 ◽  
Vol 10 (4) ◽  
pp. 471-477
Author(s):  
Merin Loukrakpam ◽  
Ch. Lison Singh ◽  
Madhuchhanda Choudhury
Keyword(s):  
Energy Saving ◽  
Relative Error ◽  
Energy Efficient ◽  
Piecewise Linear ◽  
Arithmetic Operation ◽  
Design Procedure ◽  
Digital Signal ◽  
Maximum Relative Error ◽  
Square Function ◽  
Efficient Design

Background:: In recent years, there has been a high demand for executing digital signal processing and machine learning applications on energy-constrained devices. Squaring is a vital arithmetic operation used in such applications. Hence, improving the energy efficiency of squaring is crucial. Objective:: In this paper, a novel approximation method based on piecewise linear segmentation of the square function is proposed. Methods: Two-segment, four-segment and eight-segment accurate and energy-efficient 32-bit approximate designs for squaring were implemented using this method. The proposed 2-segment approximate squaring hardware showed 12.5% maximum relative error and delivered up to 55.6% energy saving when compared with state-of-the-art approximate multipliers used for squaring. Results: The proposed 4-segment hardware achieved a maximum relative error of 3.13% with up to 46.5% energy saving. Conclusion:: The proposed 8-segment design emerged as the most accurate squaring hardware with a maximum relative error of 0.78%. The comparison also revealed that the 8-segment design is the most efficient design in terms of error-area-delay-power product.

scholarly journals 1/f Noise Modelling and Characterization for CMOS Quanta Image Sensors

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5459
Author(s):  
Wei Deng ◽  
Eric R. Fossum
Keyword(s):  
Analog Circuits ◽  
Image Sensor ◽  
Image Sensors ◽  
Correlated Double Sampling ◽  
Cmos Image Sensors ◽  
Source Follower ◽  
Cmos Analog Circuits ◽  
Different Origins ◽  
Noise Models ◽  
Fitting Model

This work fits the measured in-pixel source-follower noise in a CMOS Quanta Image Sensor (QIS) prototype chip using physics-based 1/f noise models, rather than the widely-used fitting model for analog designers. This paper discusses the different origins of 1/f noise in QIS devices and includes correlated double sampling (CDS). The modelling results based on the Hooge mobility fluctuation, which uses one adjustable parameter, match the experimental measurements, including the variation in noise from room temperature to –70 °C. This work provides useful information for the implementation of QIS in scientific applications and suggests that even lower read noise is attainable by further cooling and may be applicable to other CMOS analog circuits and CMOS image sensors.

Effect of proton radiation on 8T CMOS image sensors for space applications

2021 ◽  
pp. 1-9
Author(s):  
Jing Fu ◽  
Jie Feng ◽  
Yu-Dong Li ◽  
Qi Guo ◽  
Ying Wei ◽  
...  
Keyword(s):  
Image Sensors ◽  
Proton Radiation ◽  
Space Applications ◽  
Cmos Image Sensors

scholarly journals A 12-Bit Column-Parallel Two-Step Single-Slope ADC With a Foreground Calibration for CMOS Image Sensors

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 172467-172480
Author(s):  
Qihui Zhang ◽  
Ning Ning ◽  
Jing Li ◽  
Qi Yu ◽  
Kejun Wu ◽  
...  
Keyword(s):  
Image Sensors ◽  
Cmos Image Sensors ◽  
Foreground Calibration

Performance of Deep-Depletion Buried-Channel $n$-MOSFETs for CMOS Image Sensors

2013 ◽  
Vol 60 (12) ◽  
pp. 4173-4179 ◽  
Author(s):  
Konstantin D. Stefanov ◽  
Zhige Zhang ◽  
Chris Damerell ◽  
David Burt ◽  
Arjun Kar-Roy
Keyword(s):  
Image Sensors ◽  
Buried Channel ◽  
Cmos Image Sensors

scholarly journals Label-Free Electrochemical Biosensor Based on Au@MoS₂–PANI for Escherichia coli Detection

Chemosensors ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 49
Author(s):  
Pushap Raj ◽  
Man Hwan Oh ◽  
Kyudong Han ◽  
Tae Yoon Lee
Keyword(s):  
Escherichia Coli ◽  
Bacterial Infections ◽  
Limit Of Detection ◽  
Bacterial Pathogens ◽  
Cost Effective ◽  
Covalent Immobilization ◽  
Label Free ◽  
Self Assembled Monolayer ◽  
Detection Range ◽  
Linear Detection

Bacterial infections have become a significant challenge in terms of public health, the food industry, and the environment. Therefore, it is necessary to address these challenges by developing a rapid, cost-effective, and easy-to-use biosensor for early diagnosis of bacterial pathogens. Herein, we developed a simple, label-free, and highly sensitive immunosensor based on electrochemical detection using the Au@MoS₂–PANI nanocomposite. The conductivity of the glassy carbon electrode is greatly enhanced using the Au@MoS₂–PANI nanocomposite and a self-assembled monolayer of mercaptopropionic acid on the gold nanoparticle surface was employed for the covalent immobilization of antibodies to minimize the nonspecific adsorption of bacterial pathogens on the electrode surface. The biosensor established a high selectivity and sensitivity with a low limit of detection of 10 CFU/mL, and detected Escherichia coli within 30 min. Moreover, the developed biosensor demonstrated a good linear detection range, practical utility in urine samples, and electrode regenerative studies.

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