# Development of a Portable and Inexpensive Ultrasound Imaging Device for Use in the Developing World

## ABSTRACT

People in developing countries have limited access to life-saving diagnostic equipment. Because medical imaging devices are stationary and costly, there exists a need for imaging technology that is not only accurate and portable, but also inexpensive. To address this issue, we developed and tested an inexpensive portable ultrasound device. Three microprocessing boards compose the device: a SeeedStudio BeagleBone Green, an Arduino Uno, and a Murgen board. The BeagleBone powers and controls the Murgen board. The Murgen board pulses a 5MHz single-element transducer, rotated by the Arduino, and receives the echoes. We programmed acquisition and image reconstruction procedures for the device and assessed the signal-to-noise ratio (SNR) in images of high-contrast graphite laboratory phantoms as well as standard clinical phantoms manufactured by Computerized Imaging Reference Systems, Inc. (CIRS). Reconstructed images of laboratory phantoms yielded an SNR of 9.3 dB, which was acceptable for imaging high-contrast targets. Some targets in the CIRS phantom were visible, but the SNR remained below an acceptable threshold, revealing the need for additional signal processing and noise reduction.  All in all, we have demonstrated the feasibility of, identified further improvement for, and laid the foundation for an inexpensive portable ultrasound device.

### INTRODUCTION.

Accurate medical imaging is necessary for proper diagnoses as patients often do not show outward symptoms until it is too late for treatment. However, people in developing countries have limited access to life-saving diagnostic methods, often having to travel long distances to larger, more affluent cities for medical care [1]. A mobile and low-cost imaging option has the potential to benefit patients in remote areas who have limited access to such devices. Because ultrasound does not require large scanners like magnetic resonance imaging (MRI) or computerized tomography (CT), it is the ideal modality for a portable imaging device. In this project, an ultrasound device that is inexpensive, portable, and accurate has been developed and tested.

Ultrasound devices transmit and receive sound waves via a transducer. The time difference between wave transmission and reception can be mapped to a one-dimensional image. This type of imaging is called one-dimensional (A-mode) imaging. Though A-mode imaging is inexpensive to implement because it uses only one transducer, has limited use for medical diagnostics. Two-dimensional (B-mode) images are more widely used in medical ultrasound applications, such as prenatal, trauma, and cancer imaging [2]. However, B-mode devices usually consist of multiple transducers, each with its own receive circuit, and thus are prohibitively expensive. In order to achieve two-dimensional imaging while maintaining a low cost, in our device the transducer is rotated, and one-dimensional images are taken in rapid succession as the transducer sweeps through a 60-degree angle. This is called sector scanning.

Sector scanning can be used to generate B-mode images while helping keep the device low-cost. Furthermore, integrated circuits exist for all necessary components of an ultrasound scanner, including transmit-receive switches, noise amplifiers, and ADC converters. These can be combined with minimal computing power, with the potential to cost less than $300. In this study, a single-element ultrasound device was developed and tested in order to assess the feasibility of generating accurate ultrasound images for a low cost. Portable ultrasound has been the focus of various recent research studies [1], one of which was tested in a Level-I trauma hospital in Detroit, Michigan. Kirkpatrick et al. developed and tested the effectiveness of a portable ultrasound device (HHFAST) to perform Focused Assessment with Sonography for Trauma (FAST) ultrasound exams [3]. The HHFAST Sonosite 180, a 2.4kg portable ultrasound scanner, was implemented in a hospital triage setting, with a 97% accuracy in predicting the clinical outcome. Kirkpatrick et al. shows that a small and portable ultrasound device would be feasible for getting clinically useful and valuable data that could be used for diagnosis. While the Sonosite imaging device provides an accurate and portable option, it costs up to$25,000 [4]. The next step towards ubiquitous medical imaging technology is the development of inexpensive diagnostic devices.

### MATERIALS AND METHODS.

#### Board Descriptions.

The device consisted of a 5MHz single-element transducer and three open-source microprocessing boards each with a different task to perform: a SeeedStudio BeagleBone Green, a Murgen board, and an Arduino Uno. The BeagleBone is a low-cost development platform that runs Debian Linux [5]. It powered and controlled the timing of the Murgen board, developed by Luc Jonveaux et al. as a novel platform for a low-cost ultrasound machine [6] that functions as transmit-receive switch and high voltage pulser. The Murgen board also contains circuitry for envelope detection and analog-to-digital conversion, but testing these components was beyond the scope of this project. The Murgen board and BeagleBone have high sampling rates and fast image processing. The Arduino is an open-source microprocessing board. As its limited clock speed of 16MHz [7] is less than the 25MHz sampling rate needed for ultrasound, it was only used to rotate the Servo motor.

### ACKNOWLEDGEMENT.

I would like to thank Tony Phipps for use of his phantoms and for advice throughout the project, Vandiver Chaplin for help and advice in writing code, Jiro Kusunose for use of the Verasonics scanner, the Caskey Lab at Vanderbilt University Institute for Imaging Science, and Brett Byram for use of the CIRS phantom.

### REFERENCES.

1. Sippel, K. Muruganandan, A. Levine, S. Shah, Review Article: Use of Ultrasound in the Developing World. International Journal of Emergency Medicine. 4, 1-11 (2011).
2. Kirkpatrick, R. Simmons, R. Brown, S. Nicolaou, S. Dulchavsky, The hand-held FAST: Experience with hand-held trauma sonography in a level-I urban trauma center. International Journal of the Care of the Injured. 33, 303-308 (2002).
3. Suetens, Fundamentals of Medical Imaging (Cambridge University Press, New York, ed. 2, 2013), pp. 128-158. [Second edition]
4. “Ultrasound Comparison Guide,” Providian Medical Equipment [Online]. Available: http://www.providianmedical.com/vu-wp0/wp-content/uploads/2016/01/Providian-Medical-Ultrasound-Machine-Comparisons.pdf [June 30, 2016].
5. Molloy, Exploring BeagleBone, Indianapolis, IN: John Wiley & Sons, Inc., 2015 [Online]. Available: https://dl.dropboxusercontent.com/u/25361/exploring-beaglebone.pdf [May 26, 2016].
6. Jonveaux, et al., “Murgen: An Open-Source Ultrasound Imaging dev-kit side project,” [Online]. Available: https://hackaday.io/project/9281-murgen [May 25, 2016].
7. “Arduino Uno,” [Online]. Available: https://www.arduino.cc/en/Main/ArduinoBoardUno [June 30, 2016].
8. SeeedStudio BeagleBone Green, [Online]. Available: http://www.seeedstudio.com/wiki/images/thumb/1/17/450px-BBG3.jpg/450px-450px-BBG3.jpg
9. Arduino Uno and Servo Motor Fritzing Diagram, [Online]. Available: http://dm.ncl.ac.uk/clarerobertson/files/2013/11/sweep_BB.png
10. T. Bushberg, J.A. Seibert, E.M. Leidholdt, J.M. Boone, The Essential Physics of Medical Imaging (Wolters Kluwer Health/Lippincott Williams & Wilkins, Philadelphia, ed. 3, 2012), pp. 280-281. [Third edition]
11. CIRS, Norfolk, VA [Online]. Available: http://www.cirsinc.com/file/Products/040GSE/040GSE%20DS%20101915.pdf

Posted by on Thursday, June 8, 2017 in May 2017.