Project Overview

Wireless Data Acquisition (wDAQ) system to capture/transmit high-frequency analog signals to a device in real time using Wi-Fi technology

Problem Statement

Most modern data acquisition systems, also known as oscilloscopes, require BNC cables to connect to and analyze electrical and physical signals. BNC cables are a type of coaxial cable, which are essentially cords that carry an electrical conductor, surrounded by a protective outer layer, to transmit electrical signals from an electrical circuit or physical body to an external device (i.e., the oscilloscope or data acquisition system) for analysis. In addition to these hefty cables, which are often over two feet long, the data acquisition systems require a corded power supply, and they typically use a built-in graphical display to view signals, as well as physical buttons and knobs to adjust display settings, which take up space and increase the size of the device. The combination of cables, power cords, buttons, and display screens make traditional oscilloscopes and data acquisition systems bulky, heavy devices that are not friendly for mobile data gathering (e.g., attempting to monitor an electrical or physical signal outside of a lab setting) or applications of data acquisition devices within larger systems.

To tackle the size and mobility constraints associated with commercial oscilloscopes, our team wants to create a wireless data acquisition system, powered by a rechargeable battery, that enables mobile real-time data communication using Wi-Fi and is compact enough to fit in about a 1"x5" space. The reason we are striving for mobile capabilities and a small size for our device is because it will be used within a Photoacoustic Tomography (PAT) system in the Biomedical Imaging Laboratory at Iowa State University. A PAT system is a noninvasive device used for biomedical imaging that enables the physical anatomy, oxygen and blood levels, and other biological properties of animals and humans to be identified, like an ultrasound. (ISU’s lab will be using the device on small animals.) To accompany the data acquisition device, our team will create a graphical user interface in a software called LabVIEW that enables users to view and analyze data from an external source (e.g., a computer or tablet).

By developing a Wi-Fi connected, battery-powered device that is compatible with external software for data analysis, our team will eliminate the need for BNC cables, power cords, and physical buttons in an oscilloscope and, consequently, be able to easily integrate data acquisition technologies within a larger application.

Intended Functionality

• We want to create a wireless data acquisition device that can acquire, amplify, and digitize analog signals, and send data to a LabVIEW user interface over Wi-Fi at high speeds.
• We want our device to be compact and portable enough to be implemented in a rotating transducer array for application in a Photoacoustic Tomography (PAT) System

Requirements

• Functional: Amplifies a small radio-frequency (RF) analog (1-10 mV, 0.1-20 MHz) signal to a 1-3 V output and digitizes it at a rate of 100 MSPS, before transmitting it to a user interface at a rate of 100 Mbps (megabits per second)​
• Physical and Logistical: Wireless (battery-powered and Wi-Fi connected) and compact enough to fit in an approximately 1" by 1" by 5" volume​
• User Experiential: Easy and straightforward to use for users of varied skill levels; seamlessly connected to the device via Wi-Fi with the capability to acquire and analyze data from multiple wDAQ devices at once (since ~20 devices will be connected to the PAT System)