801 University Blvd Se

University Park, NM, United States

801 University Blvd Se

University Park, NM, United States
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Uzzal M.M.,University of New Mexico | Zarkesh-Ha P.,University of New Mexico | Szauter P.,801 University Blvd Se | Edwards J.,University of New Mexico | Edwards J.,801 University Blvd Se
International System on Chip Conference | Year: 2017

In this paper the noise behavior of a novel Avalanche Ion Sensitive Field Effect Transistor (A-ISFET) is presented. The A-ISFET is an ion sensitive field effect transistor that can inherently deliver high sensitivity through a multiplication factor, M, similar to an avalanche photodiode, where they are used when the input signal is very weak. A physical model for both intrinsic and extrinsic noise mechanisms in an A-ISFET is derived. We developed an analytical model for the A-ISFET signal-to-noise ratio (SNR) to maximize SNR at a specific operating point, as a function of current components, noise sources and overall structure and operation. Based on our noise model, an optimum value for the multiplication gain is found to maximize SNR sensitivity of the A-ISFET sensor. © 2016 IEEE.


Uzzal M.M.,University of New Mexico | Zarkesh-Ha P.,University of New Mexico | Zarkesh-Ha P.,801 University Blvd Se | Szauter P.,801 University Blvd Se | And 2 more authors.
International System on Chip Conference | Year: 2017

A physical operation-based drain current model is developed for novel avalanche ISFET (A-ISFET). Mobility degradation effect has been included into the model. The avalanche breakdown effects are modeled by using a previously developed impact ionization based finite multiplication breakdown model. Comparisons are made with SPICE simulation and experimental measured results, and a very good match is found across breakdown region of operation. © 2016 IEEE.


Godoy S.E.,University of New Mexico | Godoy S.E.,University of Concepción | Hayat M.M.,University of New Mexico | Ramirez D.A.,801 University Blvd Se | And 4 more authors.
Biomedical Optics Express | Year: 2017

Skin cancer is the most common cancer in the United States with over 3.5M annual cases. Presently, visual inspection by a dermatologist has good sensitivity (> 90%) but poor specificity (< 10%), especially for melanoma, which leads to a high number of unnecessary biopsies. Here we use dynamic thermal imaging (DTI) to demonstrate a rapid, accurate and non-invasive imaging system for detection of skin cancer. In DTI, the lesion is cooled down and the thermal recovery is recorded using infrared imaging. The thermal recovery curves of the suspected lesions are then utilized in the context of continuous-time detection theory in order to define an optimal statistical decision rule such that the sensitivity of the algorithm is guaranteed to be at a maximum for every prescribed false-alarm probability. The proposed methodology was tested in a pilot study including 140 human subjects demonstrating a sensitivity in excess of 99% for a prescribed specificity in excess of 99% for detection of skin cancer. To the best of our knowledge, this is the highest reported accuracy for any non-invasive skin cancer diagnosis method. © 2017 Optical Society of America.


Godoy S.E.,University of New Mexico | Ramirez D.A.,801 University Blvd Se | Myers S.A.,801 University Blvd Se | Von Winckel G.,801 University Blvd Se | And 5 more authors.
Infrared Physics and Technology | Year: 2015

Dynamic thermal imaging (DTI) with infrared cameras is a non-invasive technique with the ability to detect the most common types of skin cancer. We discuss and propose a standardized analysis method for DTI of actual patient data, which achieves high levels of sensitivity and specificity by judiciously selecting pixels with the same initial temperature. This process compensates the intrinsic limitations of the cooling unit and is the key enabling tool in the DTI data analysis. We have extensively tested the methodology on human subjects using thermal infrared image sequences from a pilot study conducted jointly with the University of New Mexico Dermatology Clinic in Albuquerque, New Mexico (ClinicalTrials ID number NCT02154451). All individuals were adult subjects who were scheduled for biopsy or adult volunteers with clinically diagnosed benign condition. The sample size was 102 subjects for the present study. Statistically significant results were obtained that allowed us to distinguish between benign and malignant skin conditions. The sensitivity and specificity was 95% (with a 95% confidence interval of [87.8% 100.0%]) and 83% (with a 95% confidence interval of [73.4% 92.5%]), respectively, and with an area under the curve of 95%. Our results lead us to conclude that the DTI approach in conjunction with the judicious selection of pixels has the potential to provide a fast, accurate, non-contact, and non-invasive way to screen for common types of skin cancer. As such, it has the potential to significantly reduce the number of biopsies performed on suspicious lesions. © 2014 Elsevier B.V. All rights reserved.


Zarkesh-Ha P.,University of New Mexico | Edwards J.,University of New Mexico | Szauter P.,801 University Blvd Se
IEEE Biomedical Circuits and Systems Conference: Engineering for Healthy Minds and Able Bodies, BioCAS 2015 - Proceedings | Year: 2015

In this paper a novel Avalanche Ion Sensitive Field Effect Transistor (A-ISFET) is presented and experimentally demonstrated. It is shown that a similar model for impact ionization in avalanche photodiodes is also applicable for A-ISFETs. To demonstrate the benefit of A-ISFETs, a test chip with ∼35,000 arrays of A-ISFETs is designed and fabricated using a standard 0.25μm CMOS process from TSMC. The transconductance of the fabricated A-ISFET is measured for various Vgs and Vds, to optimize the bias point for maximum sensitivity in avalanche mode. A multiplication gain of ∼6.0 was experimentally achieved. Using the optimum bias points, the arrays of A-ISFETs are also tested with sample solutions to demonstrate the increase in sensitivity due to multiplication gain. © 2015 IEEE.

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