Novel optical design for improved signal to noise ratio of a real time M-squared measurement

2016 ◽  
Author(s):  
Michael Scaggs
Keyword(s):  
Real Time ◽  
Signal To Noise Ratio ◽  
Optical Design ◽  
Signal To Noise ◽  
Noise Ratio

Development and Characterization of an Electrocochleography-Guided Robotics-Assisted Cochlear Implant Array Insertion System

2021 ◽  
pp. 019459982110492
Author(s):  
Allan M. Henslee ◽  
Christopher R. Kaufmann ◽  
Matt D. Andrick ◽  
Parker T. Reineke ◽  
Viral D. Tejani ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Real Time ◽  
Signal To Noise Ratio ◽  
Electrode Array ◽  
High Signal ◽  
Animal Testing ◽  
Signal To Noise ◽  
Noise Ratio ◽  
Hearing Outcomes

Objective Electrocochleography (ECochG) is increasingly being used during cochlear implant (CI) surgery to detect and mitigate insertion-related intracochlear trauma, where a drop in ECochG signal has been shown to correlate with a decline in hearing outcomes. In this study, an ECochG-guided robotics-assisted CI insertion system was developed and characterized that provides controlled and consistent electrode array insertions while monitoring and adapting to real-time ECochG signals. Study Design Experimental research. Setting A research laboratory and animal testing facility. Methods A proof-of-concept benchtop study evaluated the ability of the system to detect simulated ECochG signal changes and robotically adapt the insertion. Additionally, the ECochG-guided insertion system was evaluated in a pilot in vivo sheep study to characterize the signal-to-noise ratio and amplitude of ECochG recordings during robotics-assisted insertions. The system comprises an electrode array insertion drive unit, an extracochlear recording electrode module, and a control console that interfaces with both components and the surgeon. Results The system exhibited a microvolt signal resolution and a response time <100 milliseconds after signal change detection, indicating that the system can detect changes and respond faster than a human. Additionally, animal results demonstrated that the system was capable of recording ECochG signals with a high signal-to-noise ratio and sufficient amplitude. Conclusion An ECochG-guided robotics-assisted CI insertion system can detect real-time drops in ECochG signals during electrode array insertions and immediately alter the insertion motion. The system may provide a surgeon the means to monitor and reduce CI insertion–related trauma beyond manual insertion techniques for improved CI hearing outcomes.

Method to Determine Tissue Fluorescence Efficiency in vivo and Predict Signal-to-Noise Ratio for Spectrometers

1998 ◽  
Vol 52 (7) ◽  
pp. 943-951 ◽  
Author(s):  
E. V. Trujillo ◽  
D. R. Sandison ◽  
U. Utzinger ◽  
N. Ramanujam ◽  
M. Follen Mitchell ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Optical Design ◽  
Tissue Type ◽  
Excitation Wavelength ◽  
Cervical Tissue ◽  
Signal To Noise ◽  
Fluorescence Efficiency ◽  
Tissue Fluorescence ◽  
Noise Ratio

Recent clinical trials have demonstrated the potential of fluorescence spectroscopy for in vivo diagnosis of pathology. There is significant potential to reduce the cost and complexity of instrumentation to measure tissue spectra; however, careful analysis is required to maximize performance and minimize cost. One measure of performance is the signal-to-noise ratio (SNR) of the resulting data. This paper describes a method to predict the SNR of a given optical design for a particular tissue application. In order to calculate the expected SNR, two pieces of information are required: (1) the throughput and inherent noise of the system and (2) a quantitative relationship between the illumination energy and the resulting tissue fluorescence available for collection, which we define as the tissue fluorescence efficiency (FE). We present a method to calculate the fluorescence efficiency of tissue from in vivo measurements of tissue fluorescence. We report FE measurements of the normal and precancerous human cervix in vivo at 337, 380, and 460 nm excitation. We also present and evaluate a method to estimate the throughput and noise of various spectrometers and predict the expected SNR for tissue spectra by using the measured tissue FE. For squamous cervical tissue, as the degree of the disease increases, FE decreases, and as the excitation wavelength increases, FE decreases. Cervical tissue FE varies more than two orders of magnitude, depending on the tissue type and on the excitation wavelength used. Our SNR calculations, based on measured values of tissue FE, demonstrate agreement within a factor of 1.3 of the measured SNR on average. This method can be used to estimate the performance of different spectrometer designs for clinical use.

Visualizing cellular sodium hydrosulfite (Na2S2O4) using azo-based fluorescent probes with a high signal-to-noise ratio

2019 ◽  
Vol 7 (5) ◽  
pp. 730-733 ◽  
Author(s):  
Baoli Dong ◽  
Wenhui Song ◽  
Xiuqi Kong ◽  
Nan Zhang ◽  
Weiying Lin
Keyword(s):  
Real Time ◽  
Fluorescent Probes ◽  
Reliable Method ◽  
Signal To Noise Ratio ◽  
High Signal ◽  
Signal To Noise ◽  
Sodium Hydrosulfite ◽  
Depth Study ◽  
Noise Ratio

Developing a reliable method to detect Na2S2O4 in real time is of great importance for the in-depth study of its toxicity to humans and to allow it to be safely handled.

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