A low-light-level sensor for medical diagnostic applications

Abstract

Abstract-A low-level light sensor and preprocessor for a disposable medical probe is described. A 10-Hz 4-A/cm 2 input optical signal in the visible spectrum is assumed in chemoluminant diagnostic applications. A single-bit first-order sigma-delta modulator has been employed for analog-to-digital conversion, thanks to its robustness, simplicity, inherent linearity, and high signal-to-noise ratio. A current buffer has been used to replicate the weak signal with sufficient bandwidth. Tests have shown the feasibility of this approach, and have also enabled improvements of the design.

On-chip biofluorescence imaging inside a brain tissue phantom using a CMOS image sensor for in vivo brain imaging verification

“…We found that the detection limit of 1 nM of fluorophore could be reached when using the photosensor. Given that many schemes have been reported to increase the sensitivity and bandwidth of CMOS image sensors [35][36][37][38][39][40], improvement in sensitivity and imaging speed can be expected. Based on our targeted application for detection of AMC released from the QGSK-MCA substrate, the reaction kinetics involved favors detection within the second or sub-second temporal resolution range.…”

Channel Charge Injection analysis and its modeling in z-domain for switched-capacitor integrators

“…(1-expf-t/rj] VGn(t)= Vdd·exp(-t/r) Having modeled the clock signal , each trans istor resistance amount versus time will be: According to (11) and (12), generated error rises versus time and reaches to its maximum amount at phase #2 which is defmed in Table I. Fig.…”

Efficiency Analysis for a Mixed-Signal Focal Plane Processing Architecture

“…The performance of these circuits has been studied with standard CMOS implementation [32][33][34]. Sigma-delta converters have been successfully integrated with CMOS image sensors [35][36][37].…”