Development of point-of-care, biomedical optics technologies to non-invasively characterize tissue hemodynamics

We develop biomedical optics technologies that non-invasively characterize tissue hemodynamics, including tissue composition, blood flow, and metabolic rate of oxygen consumption. To date, we have translated these technologies into several clinical studies which include sickle cell disease, pediatric sleep apnea, monogenic vascular diseases, and pre-eclampsia. Within these patient cohorts, we apply these techniques to a range of applications such as identifying disease states based on changes in tissue composition/metabolism or monitoring changes in tissue hemodynamics in response to therapeutic intervention. 

Broadly, the student will assist in the testing and development of new optical imaging devices and the characterization of device performance with data acquired in the NIH clinical center. During the summer, the student will:

1. Contribute to the development and testing of in vitro models that simulate physiological processes such as tissue oxygen consumption or blood coagulation
   
    
2. Participate in the collection of clinical data from patients with sickle cell disease or monogenic vascular diseases
   
    
3. Perform data analysis to quantify tissue hemodynamic data from various clinical cohorts and compare to clinically obtained biomarkers

Throughout these projects, students will receive mentorship and gain experience with optical instrumentation design, data analysis techniques, and translational clinical research. Students will also interact with both engineers and clinicians as they take various optical technologies from the laboratory to the clinic. 

The student should have an interest in biomedical engineering, device development, and clinical translation. Experience with computer programming (MATLAB, Python) is encouraged, but not required. 

Specific projects may include:

1. Blood coagulation in sickle cell disease
   
   
   
   Underpinned by emerging results from our sickle cell disease clinical study, the student will lead the development of an in vitro model of blood coagulation. They will manufacture and characterize a blood flow model and establish a blood de-oxygenation protocol. The student will then implement their model in a study to assess how our clinical measurements may relate to deoxygenation and coagulation of sickled hemoglobin. 
   
    
2. Blood pressure tracking in healthy adults
   
   
   
   Traditional blood pressure measurements, normally taken in a doctor’s office using a device with an arm cuff, offer only momentary snapshots. This method fails to capture the dynamic variations in blood pressure and other health-related markers over extended periods, such as throughout a day or across different days, weeks, and months.
   
   
   
   In the consumer market, health wearables can track markers such as heart rate, heart rate variability, skin conductance, oxygenation, and some others. Many consumer wearables include the hardware to carry out photo-plethysmography (PPG), which is used for the oxygenation, and heart rate-related metrics. However, there is a notable gap in the market: none of these consumer wearables can monitor blood pressure. 
   
   
   
   The student will work with a team of engineers to develop new algorithms to track blood pressure and other dynamic health metrics in people who participated in one of our ongoing clinical studies. The result will be to enable wearables to capture a fuller, more detailed picture of an individual’s health.
   
    
3. Characterization of depth sensitivity for multi-modal optical techniques
   
   
   
   While attractive candidates for point-of-care hemodynamic assessment, near-infrared spectroscopy (NIRS) techniques remain susceptible to heterogeneous anatomic locations such as the forearm which is comprised of skeletal muscle overlaid with skin and adipose tissue or the forehead in which light must pass through the scalp and skull before reaching the brain. Separation of the hemodynamic effects from the different tissue layers would enable better recovery of hemodynamic changes in the underlying tissue independent of the more superficial layers. Over the summer, the student will aid in the construction of an in vitro tissue model with adjustable parameters that can facilitate testing for multiple optical devices.