Engineering Portfolio
The human hand is a complex mechanical system; Composed of 27 bones, 27 joints, 34 muscles, and over 100 ligaments and tendons. With many of these joints capable of multiple degrees of freedom, the position of each segment can vary based on muscle contraction, the shape of the object grasped, or user preference. A parametric and generative model of the human hand allows for the ergonomic design of tools, interfaces, and controls. A parametric model allows for the movement of joints either by input angles or in conjunction with the device being designed. A generative model also presents unique advantages, allowing the accurate modeling of any size hand based on easily measurable external elements. This report documents the creation of a model in Seimens NX that is both generative and parametric.
Neuromechanics is a body of research that seeks to understand how the body moves. A method of neuromechanical study is "Human Robotics," where the human system is treated as a system similar to a mechanical system. Feedforward planning, nerve pulses, muscle recruitment, feedback, and inertia can be approximated mathematically to create a model that estimates the movement of the human body. These models of movement can then be used to simulate biomechanics, quantify disability, influence human-mechanical systems such as exoskeletons, and develop therapy protocols for recovery. This report documents a preliminary model that can simulate the movement of the upper limb of the human body. This model can be expanded to include more joints, or modified to simulate other systems.
Fatigue analysis of Nitinol-based mechanisms presents unique challenges compared to similar analyses performed on non-superelastic alloys. While standard metal fatigue can be investigated using S-N curves and stress-based Goodman diagrams, a more accurate method for nitinol uses strain measurements. This report details a sample investigation of the fatigue life of a nitinol-based stent.
This project, written in Python, calculates the center of mass of a ballerina moving through various positions on a Bosu-Ball. After ingesting the video and pre-recorded position data, the program generates a visual of the skeleton, calculates the center of mass of each body segment, and then estimates the center of mass of the whole body. The analysis uses anthropomorphic estimates for the COM location. The analysis can be easily modified for 3-dimensional position and inverse-kinematic analysis.
This report summarizes the analysis of a simple stent design in a blood vessel. Tests include the expansion of a martensitic nitinol stent to a desired diameter, compression to its insertion diameter, it's implantation and interation with blood vessels experiencing cyclic blood pressures.
Master's Project: EnsuriNG Engineering Innovation in Health Project
The Ensuring project was my Master's project that occurred in the Engineering Innovation in Health program. Lasting a full year, the project began as a problem brought to the EIH program by a neonatal surgeon. Seeking to better confirm the placement of nasogastric tubes in neonates, our group was tasked with finding a solution that is both reliable and accusable. Tasks I performed include:
Acting as lead engineer with a team consisting of a Mechanical Engineering and Materials Engineering undergraduate students.
Developing requirements framework by which our solution was judged that translated the customer desired with measurable milestones.
Exploring various concepts and current technologies through research and communication with other University of Washington departments.
Creating a testing bench that could objectively measure the improvement in identifying the NG tube position using light and/or sound.
Creating a prototype that used lasers and fiber-optics that was capable of shining through the skin to shown the location of the NG tube.
Presenting our project at the EIH spring symposium to an audience of clinicians and engineers.
Creating and submitting a provisional patent.
Creating a testing bench and experimental framework to measure the improvement of the EnsuriNG device using volunteers.
Coordinating with cadaver labs and Veterinarians to test the device on animal or human cadavers
Co-authoring documentation to allow for the transfer of the project to future engineers.
The poster below was presented at the EIH spring symposium, where I gave an onstage pitch, and participated in a 2 hour long poster session.
Degradation of Polymers in a Blood Enviroment
In a project sponsored by Merit Medical, I was tasked with investigating the mechanical properties of various polymers exposed to a blood-like environment over a period of 6 months. The experiment showed that PDLGA lost its strength following a few weeks of blood exposure, while the other polymers had no significant degradation over the 6 month experiment. Tasks I performed include:
Acting as lead researcher with a team consisting of two other Mechanical Engineering undergraduates.
Developing a testing method.
Designing and building jigs used for tensile testing in a saline solution at body temperature (Note, the image shown is the final test on PDLGA which degraded to the point of experiencing 300%+ deformation at small forces and reaching the limits of the Tensile tester. All other tests remained in saline solution)
Manufacturing the testing fixture that held test samples in a blood like environment, which included a pump, incubator, and CO2 monitor/control.
Periodically removing samples at random to perform tensile tests.
Statistical analysis of results
Presenting results at the Biomedical Engineering Society conference.
Combining the results of the experiment with previous work performed in the lab to present a gradually expanding cardiac stent implant to the president of Merit medical.
Design of a Surgical Tool that can Release a Press-Fit Locking Mechanism on a Lumbar Fusion Device.
I was tasked with a difficult project that had been unsolved by multiple previous engineers. An in-development lumbar fusion device required a tool that could remove a 1000 lbf press fit within space constrained surgical wound. I successfully created a prototype that could remove the press-fit implant. Tasks I performed include:
Created of a kinematic mathematical model that can calculate the stresses on links and pins in an assembly.
Designing an instrument with the help of the model that could generate the required load in the surgical envelope.
Creating manufacturing drawings and defining critical dimensions and assembly method.
Communicating with a local manufacturing shop to create a prototype used in a cadaver lab to successfully remove the implant.
Creating documentation transferring the instrument to another engineer for further refinement.
Design of Surgical Screwdriver Capable of Placing and Locking orthopedic Screws
To simplify the implantation of the cervical fusion device, I designed a screwdriver that could reliable hold an othropedic screw, drive the screw into bone, and then actuate a locking device that prevented the screw from backing out of the implant. Tasks I performed include:
Creating of an inputs/outputs document that defined the design criteria.
Creating models and an assembly of the driver in Creo (CAD software).
Creating manufacturing drawings and defining critical dimensions to be inspected.
Interfacing with a local manufacturer to refine the design and modify elements of the driver.
Bachelor Capstone Project: Redesign of the Steering Mechanism used in GE portable X-Rays
Mechanical Testing of Orthopedic Screws used in Spinal Surgery
I was tasked with investigating the actuation force required to lock orthopedic screws into a cervical spine fusion plate, along with the force that the screws would withstand prior to failure. I performed the testing and recommended various improvements to the implant design and new surgical instruments. Tasks I performed include:
Creating the testing method
Manufacturing testing jigs and supplies.
Measuring the actuation force using an Instron tensile tester.
Performed a statistical analysis of results.
Presented results to the President of Engineering and gave recommendations for the future of the device.
"CORE" Climbing Rope Cleaner Product Concept
As a project for a product design class, I worked with a group of 3 other Mechanical Engineering students to design a product. The project started from the idea generation stage, with our first tasks being related to finding a problem that needs to be solved. The project concluded with a full-scale prototype of a combination climbing rope cleaner/coiler. Tasks I performed include:
Maintaining documentation control.
Designing various mechanical elements of the device.
Performing validation testing.
Creating the manufacturing drawings.
Dynamic Control of Radiation-Based Thermal Management through Origami-Inspired Design
I worked on this research project in the BYU Compliant Mechanisms Research Group. My group was tasks with creating a research project related to origami inspired design. The project explored the use of origami-like baffles that could be used to control the temperature of bodies in space through its folding and unfolding. Tasks I performed include:
Manufacturing the testing fixtures.
Creating test samples and preparing them for accurate measurement through thermocouple and FLIR imagery.
Performing experiments using a black body heat source.
Creating and presenting a poster of the results for the American Society of Mechanical Engineers Conference.