Designing an Articulating Ultrasound Transducer Arm for Use in Clinical Trials Treating Cocaine Use Disorder; Disparities in Substance Use Disorder and Treatment

Cocaine use disorder (CUD) affects 4.8 million Americans, causing them to suffer from the compulsive need to use the drug despite its mental, psychological, and behavioral consequences. The technical research of the project involves designing an articulating ultrasound transducer arm for use in clinical trials treating CUD, which uses low intensity focused ultrasound to stimulate the insula of the brain. In the current method of treatment, health care providers must manually hold the ultrasound transducer to the patient’s head, leading to discomfort, arm fatigue, and potentially inaccurate results, yielding the necessity of the device. The STS component of the project focuses on disparities in drug abuse and treatment. A variety of factors including race and socioeconomic status can correlate with the likelihood of abusing illicit drugs and the failure to see success in treatment attempts. The articulating arm can make a positive contribution to potential treatment options for CUD, especially for those who lack the money or resources for other treatment methods. Furthermore, it offers a quicker, patient-specific approach to aid in its unbiased effectiveness.

The technical aspect of the project used the computer aided design (CAD) and three dimensional (3D) printing in the design approach. Autodesk Fusion 360 was used to create and interpret various iterations of the design of the device. Using finite element analysis (FEA), the movements, forces, and loads of the devices were analyzed and allowed for the judgment of the necessary criteria. Required specifications for the articulating arm were extensive range of motion, durable, and easy to use. The transducer holder attachment was 3D printed and screwed into the gooseneck stand resulting in an articulating arm that could stand on its own with 360 degree range of motion to account for all shapes, sizes, and heights of patients’ heads.

The computational results gave way to a final prototype that accounted for the three main criteria mentioned. Range of motion was maximized through a ball joint mechanism in the transducer holder and in the flexibility of the gooseneck stand. Heat mapping showed minimal displacement and reaction force on the transducer holder when load was applied. Stress and fatigue testing of the gooseneck stand showed the device’s ability to bear excessive amounts of weight and undergo at least a million cycles. These metrics demonstrate the durability of the device under repetitive use. The device has a user centric design, with a set up time of 90 seconds. Overall, this device is crucial for the success of the treatment in terms of accurate measurements and can be used as a resource for other diagnostic techniques in the medical field.

The STS research question aims to understand the relationship between substance abuse and socioeconomic status. Little to no inexpensive treatment methods for CUD are available, leading to a feedback loop of addiction through maladaptive behaviors due to biochemical imbalances in the brain. Research has shown that a lower socioeconomic status is associated with an increased likelihood of abusing drugs, but it is important to determine the causation. Literature review was conducted to understand how these variables are interrelated.

The evidence from literature suggests that individuals from disadvantaged backgrounds face a disproportionately higher risk of engaging in substance use behaviors compared to those that grew up in a more affluent household. The correlation represents a mutli-faceted issue, relating economic status to educational opportunities, stress levels, and social marginalization that could be reflected in one’s struggle with substance use. The underlying root cause of the correlation could be due to a systemic, structural issue that puts people with low income at a disadvantage by increasing their susceptibility to drug use or addition and decreasing their success rate with current treatment options.

School of Engineering and Applied Science

Bachelor of Science in Biomedical Engineering

Technical Advisor: Timothy Allen

STS Advisor: Pedro Francisco

Technical Team Members: Janine Icalla, Emerson Smith