Hello! My name is Alexis, and I am a student at Georgia Institute of Technology. I will be graduating with my Master of Science in Biomedical Engineering this May. I also received my undergraduate from Georgia Tech in May 2024 with a Bachelor of Science in Biomedical Engineering, and a minor in Computing and Intelligence, graduating with highest honors. I have a strong foundation in both engineering and machine learning, and am excited to apply my interdisciplinary skills as a R&D engineer in the healthcare industry!
Here are some (not all) courses that I have completed during my time at Georgia Tech:
I have taken on many projects for medical device development, and am a Certified SolidWorks Associate in Mechanical Design. Here are a few parts and assemblies that I have made in SolidWorks using parametric modeling:
Below are some projects that I have done throughout my career:
Capstone Design: Mayo Clinic Convergence Science Program For my senior engineering design class, I worked in a team of 5 biomedical engineers and neurosurgeons sponsored by the Mayo Clinic to improve the cranial drilling experience in awake patient brain surgeries. In this project, we were able to prevent mechanical and sonic discomfort due to neurosurgical drills during awake patient brain surgeries. Throughout the process, we conducted patient and surgeon interviews to better understand the problem. We translated patient needs into design inputs, and built an active noise cancellation device to dampen the bone conducted vibrations. In doing this, we built a wave propagation model with the utilization of a control loop to dynamically assess the input and output waves. The document to the right shows our final report, which includes everything from the design inputs and IP landscape investigation, to the testing and validation of the prototype.
The Effect of Surface Type and Incline on Gastrocnemius Activation For this project, I worked in a team of 3 to measure gastrocnemius (calf muscle) activation when walking on various types of surfaces (hard or soft), and incline (declined, flat, or inclined).
We built an EMG sensor to measure gastrocnemius action on a cohort of 13 people aged 19-25 years old. Data was recorded at a sampling rate of 1200Hz, and using a bandpass filter between 20Hz and 450Hz to remove noise. By knowing the length of the trial and number of steps each participant took, we were able to calculate the frequency of their steps and used a digital band-stop filter in MATLAB to attenuate signals 5% above and below this frequency.
We found that there is an increase in activation for both inclined and declined surface in comparison to a flat surface. We also found a significant increase in muscle activation when walking on a hard surface in comparison to a soft surface. The information found in this project could be used for those who enjoy walking as a daily exercise and would like to avoid overuse injuries.
The Effects of Caffeine and Capsaicin on OE33 Cell Line Proliferation For this project, I worked in a group of 4 to determine the effects of caffine, capsaicin, and their combination on the proliferation of the OE33 (esophageal) cancer cell line.
We had 6 treatment groups for caffeine and capsaicin separately, and then 5 treatment groups with various concentrations of the two in combination, along with a control group. Once treated and incubated, a CCK-8 assay measured absorbance on all treatment groups and a MUSE annexin V assay was run to measure apoptosis effects in the 3 treatment types.
Analyzing the reults with a Tukey's multiple comparisons test and and ANOVA, we found that both caffeine and capsaicin affect OE-33 cell line proliferation at a more significant amount than the chemicals alone. In addition to capsaicin alone affecting cell proliferation, it was also found that caffeine affects proliferation, which was not expected.
I implemented a minimax tree along with alpha beta pruning to create a custom AI player to play against in a game of impact isolation. Impact Isolation is similar
to the original isolation game, where there are 2 players on a 9-by-9 grid of squares. Each player takes turns placing their piece around the board, moving in a way
like a queen in chess. When the piece is moved, the square that was previous occupied, along with the 4 blocks around it, is blocked off. The first player who is unable to
move their piece loses. The custom AI opponent utilizes a minimax tree with alpha beta pruning. When playing against a random player, it has a win ratio of 95%. When playing against another
AI player that utilizes a minimax tree of level 2, its win ratio is 75%. When it is playing against another AI player that utilizes alphabeta pruning of level 4, its win ratio is 70%.
This is a demo of the implementation and testing of robot path planning capabilities, specifically using an RRT algorithm for exploration. First, the RRT algoriuthm is implemented. The robot initially is only away of the start position, and the end position. As it creates its path to the goal, it becomes aware of the obstacles and navigates around them. The main loop of the RRT algorithm is by generating random nodes, and assembling them into a tree, adding new edges until the goal is found. Since RRT algorithm can return very convoluted paths, the performance is improved by implementing path smoothing, optimizing the path by reducing the number of nodes in the path. After undergoing smoothing, the path is returned.
In this demo, the robot is tasked with automating a warehouse. There are 2 phases: an exploration phase and a task phase. In phase I, the robot maps out its environment with a frontier-based exploration implementation. In this implementation, a rapidly exploring random tree (RRT) was used. The robot is a differential drive robot, so as it explores, the speed of the left and right wheels are set accordingly to achieve the desired velocity. To achieve this, I utilized a tuned PID controller to adjust motion updates. The algorithm terminates when all 5 landmarks are detected.
In phase II, the robot will collect packages (landmarks) while avoiding obstacles. Using the knowledge of the map from phase I, the robot navigates to the markers, and 'picks them up' by spinning around them, facing the top to grab them. As the robot drives around the map, different kinds of noise are injected into the robot's wheel velocities such as drift, offset, and random walk noise. To control the robot's motion, another PID controller is used to maintain the correct wheel velocities in the robot's differential drive.
With the implementation of a Monte Carlo Localization, the robot performs localization to estimate the its position and orientation within a known map. Each particle on the map represents a potential robot pose with an associated weight indicating its liklihood of being correct. These particles move based on the robot's motion with added noise to simulate real-world conditions. The robot is equipped with a front facing camera with a 45 degree FOV which can see markers. Based on these sensor measurements, the particle weights are adjusted, using observation of localization markers. The algorithm keeps particles with higher weights while discarding lower weight particles to focus computational resources on probable solutions. When the particles cluster around the true robot's pose (red), the algorithm considers the position estimate reliable, turning the gray estimated robot on the simulation to a green triangle.
The Viterbi algorithm is a dynamic programming algorithm that finds the most likely sequence of hidden states that results in a sequence of observed events in the context of Hidden Markov Models (HMM). In this project, I built a word recognizer for American Sign Language video sequences. It employs hidden Markov models to analyze a series of measurements from ASL videos collected for research. Using the Y coordinates of the right thumb and right hand, I encoded a HMM and built a viterbi trellis, which returns the most likely sequence of states that generated teh evidence and the probability of that sequence being correct. From this, I was able to accurately distinguish between 3 given words in ASL, 'Alligator', 'Sleep', and 'Nuts'. The gif to the right shows the signer signing the word "Alligator."
I have thorough experience creating simulations through computational modeling with various software (MATLAB, Python, PLAS, FEBio, SolidWorks, Pymol, etc.). Much of my simulation experience is in modeling biomolecular systems, predictive health models, biomedical systems, physiology, acoustics, biochemistry, and medical device tissue interaction. Here are some examples of the computational modeling I have done:










Out of all, my favorite part of BME is medical device development. I truly enjoy being involved with different phases of device development and being able to see an idea become a device over time. I have a very high amount of experience with device development, and want to show some of the prototypes that me and the various teams I've been on have made throughout my undergraduate. Below are some prototypes that my team and I have made:
Have comments, questions, or constructive criticisms? Get in touch by clicking here
Come back soon...