1. Fibrotic Liver Ultrasonic Imaging Diagnostic (FLUID) System
Student Researchers: Meredith Huszagh, Fahad Iqbal, Sara Keller, Lauren Severance, Patricia Twilley, Alison Williams BEAM Lab, Department of Biomedical Engineering, Vanderbilt University School of Engineering
Mentor: Brett Byram PhD, Assistant Professor of Biomedical Engineering
Background
Design Approach
Results
Liver fibrosis: scarring of the liver tissue
Due to liver damage and healing
Progresses through 4 stages, ending in cirrhosis
Liver cirrhosis causes more than 1 million deaths per year
Conclusion
Current Methods
The gold standard is a liver biopsy, but this method produces a qualitative result, is expensive, and the process of retrieving a liver biopsy is painful for the patient and increases their risk of bleeding and infection.
Non-invasive techniques also exist, but this imaging modalities are extremely complex and expensive and generally are not portable.
Marketability
Design Components
Diagnosis
Diet
Dippers
Non-Dippers
Non-Dipper Ratio
Healthy
Low Salt 10 2
16.7%
Normal Salt 13 4
23.5%
High Salt 11 3
21.4%
POTS 9 6
40.0% 38 29
43.3%
28.6%
Acknowledgements
Problem Statement
References
Ultrasound elastography is a promising new technique for the noninvasive diagnosis of liver fibrosis and cirrhosis. At the moment, however, this method is considered suboptimal, particularly in diagnosis of intermediate stages of the disease [2]. Recent progress in magnetic resonance and ultrasonic imaging has shown promise of an effective technique for diagnosis, but these methods are currently too expensive for implementation in most low resource environments. In addition, measurement sensitivity in the early stages of disease is a concern for these techniques [1]. The purpose of our work is to engineer a system consisting of an inexpensive, handheld, ultrasound­-based device and accompanying software for noninvasively assessing liver fibrosis and cirrhosis.
Conclusion
Hypovolemia, while a symptom of POTS, cannot be used as a predictor of the high incidence for non-dipping phenomenon seen in POTS patients. There was a decrease in the Non-Dipper Ratio for POTS patients due to diet from normal salt diet to high salt diet in the overall data. the difference wasn’t sufficient to be labeled significant during the ANOVA testing. For POTS patients data, the diet caused a significant change in the change in plasma volume. Future studies might consider the viability of a high salt diet as a treatment for POTS patient symptoms. Currently, the sample size is too small to be conducting variability tests. As more subjects get enrolled in the study, the statistical power shall increase and the ANOVA results should have more significance.
Results
Needs Assessment
ANOVA statistical tests wrtr conducted on paired data from subjects who completed the study for both low and high salt diets:
References
In order to more efficiently diagnose liver fibrosis, we propose the development of an ultrasound-based system that:
Is non-invasive to reduce patient discomfort
Requires minimal training by the provider to eliminate need of designated ultrasound technician
Is accessible to patients in low-resource environments
Takes advantage of freely available software for data processing
Uses a single-element as opposed to a multi-array transducer
Quantitatively diagnoses stage of fibrosis progression (through correlation with tissue stiffness) in a way comparable to existing gold standard
Characterizes risk of healthy tissue for becoming diseased
Provides consistent and reliable measurements despite tissue inhomogeneity
Reduces signal noise resulting from patient motion
Utilizes a processor which decreases cost and increases portability
Significant differences due to diagnosis were seen for:
Plasma volume (p=0.0031)
Change in plasma volume (p=3.45e-6)
Blood volume (p=0.0034)
Change in blood volume (p=1.41e-6)
Red blood volume (p=0.0069)
There were no significant differences due to dipping status for any blood volume parameter
Significant differences due to diet were seen for:
Plasma volume (p=0.0196)
Change in plasma volume (p=0.0072)
Change in blood volume (p=0.0299)
Looking only at the POTS patient data, significant difference due to diet was seen for:
Change in plasma volume (p= )
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Acknowledgements
Dr. Andre Diedrich (Vanderbilt University)