Individuals with impaired finger function are commonly prescribed a wrist-driven orthosis which utilizes wrist movement to open and close the fingers. However, if the individual has weak wrist extensors and flexors in addition to weak fingers, this device becomes obsolete. While multiple prosthetic devices are available to amputees, options for orthotic devices are limited. The purpose of this research is to adapt elements of successful upper limb prostheses into an open-source orthosis made with 3D printed and off the shelf materials for an individual with unilaterally impaired hand and wrist function. We continue to draw inspiration from body-powered prostheses, where the motion of other joints, such as rotation of the elbow, is used to control artificial hand motion. Gaining hand motion through the use of this device will allow users to perform daily tasks independently and with improved performance. We first created a series of prototypes to identify task specific designs. An optimal design will utilize elbow or shoulder movement to operate a low-profile hook positioned under the palm while also stabilizing the wrist and fingers which are flaccid. Input from practitioners aided in optimizing the design and process. In order to augment design acceptance, our research included user testing and feedback. Once a design was finalized, we resized the device to fit our participant. The participant then went through a series of hand functional tests which compared their ability to complete an assortment of tasks, such as lifting and moving small blocks, with and without the device. These results as well as user feedback assisted in further improvements to the overall design of the device. After completing our design, the orthosis was made open-source to make it both accessible and low-cost, while allowing users and makers to further improve upon the device.

Ankle foot orthoses (AFOs) are commonly prescribed to improve gait in individuals with cerebral palsy to stabilize gait. AFOs have also shown additional benefits in reducing the metabolic cost of walking, preventing bone deformities, and providing support during gait. The advent of the affordable 3D-printer has provided a new tool in the manufacturing of AFOs which may be able to overcome many limitations of current production methods. The purpose of this study is to improve the manufacturability and functionality of AFOs by improving AFO design and manufacturing techniques. Validation testing through the use of material testing, and multiple subject gait experiments verified the study’s results. The subjects’ lower leg was scanned with a portable 3D scanner and using this scan the AFO was form fitted to the unique shape of the subject’s foot. Parametric and non-parametric computer aided design tools were used to design the AFOs. Using a fused deposition modeling 3D printer the AFOs were fabricated using polylactide (PLA) filament. In order to adjust the stiffness of the AFO, elastic polymer bands were fabricated with polyurethane. Since a single elastic polymer band only allows for one specific AFO stiffness, multiple of elastic polymer bands might be need to be used to control the wide range of AFO stiffness. To solve this issue, the AFO was designed to have a support structure that allows for the moment arm of the elastic polymer bands to be changed, thereby adjusting to a wide range of AFO stiffness with minimum number of elastic polymer bands. Designing an open-source, 3D-printed AFO that helps rehabilitate the user could allow for low-cost, easily accessible rehabilitation devices to be common place.

Affordable 3D-printing technology may improve fabrication and accessibility of orthoses for individuals with impaired movement. The goal of my research is to leverage 3D-printing to improve the design of wrist-driven orthoses (WDOs) for individuals with spinal cord injury (SCI). Specifically, I have sought to improve comfort, aesthetics, and ease-of-use of WDOs while reducing fabrication time and increasing customizability using 3D-printing. WDOs are used by individuals who can move their wrist but have little to no mobility in their fingers. Through wrist flexion and extension, this device assists in opening and closing the hand. Unfortunately, current WDOs are laborious to fabricate, uncomfortable, and have poor aesthetics. The potential of 3D-printing for orthosis fabrication was evaluated with a group of orthotists. I modeled the 3D-printed WDO using computer-aided design software and asked orthotists to assemble and rate the device and provide feedback. The average assembly time decreased from 12+ hours for traditional metal WDOs to 1.5 hours and the device received average scores of 6.6, 6.6, and 7.6 on a scale of 1-10 (1 = poor, 10 = great) for function, aesthetics, and comfort, respectively. Based upon the orthotists’ feedback, I implemented design improvements and created a fatigue tester to ensure the device’s safety for extended use. The next round of testing focused on getting feedback from individuals who have had an SCI. The device enabled participants to achieve a three-jaw chuck grasp, which they could not achieve without it, improved performance in functional tasks, and was lighter than traditional devices. The device received average scores of 6.8, 6.5, and 8 for function, aesthetics, and comfort, respectively. Participants’ feedback was used to further improve the design. Upon finalizing the device design, fabrication method, and assembly manual, editable CAD models of the WDO design will be released for open-source development and use.

Cancer is a leading cause of mortality worldwide, and the number of new cases is projected to reach 22 million in the next two decades. Surgical resection of tissues is a standard of care for treatment of a variety of cancer patients. For the prostate, surgically removed tissues usually undergo a process of bread-loafing (cutting into 0.5-1.0 cm thickness), chemical fixation, embedding in paraffin (wax), sectioning (5-10 μm thick), staining, slide mounting and finally microscopic examination to determine whether all tumor growths have been excised. The procedure is labor-intensive, time-consuming and expensive. In addition, the majority of the prostate specimens are normal tissues that do not require detailed microscopic examination. These factors reveal the need to significantly accelerate the screening process and increase the efficient use of healthcare resources. Therefore, to reduce unnecessary processing time and costs, we proposed a fast and inexpensive imaging system to screen the surface of thick tissues for abnormality, before full histological processing. This system was designed to enable a wide imaging area and integrate deconvolution algorithms, which achieve high contrast and resolution. More specifically, the project was carried out in three phases: 1) design, construction, and optimization of a fluorescence microscope; 2) system calibration and optimization of deconvolution algorithms; and 3) system validation using fresh human tissues. The system is capable of generating a 1 x 1 cm² image in a few minutes with 4 nm resolution. Success of such a system will facilitate clinical translation and increase efficiency of histopathological procedures, which are beneficial to both patients and healthcare providers.

Oxygen transportation in red blood cells occurs via a protein called hemoglobin. When hemoglobin is either absent, flawed, or impaired, the transportation of oxygen is hindered and this is known as anemia. Due to the prevalence and dangers of anemia, our goal is to effectively measure the concentration of hemoglobin in small volumes of a patient’s blood in order to diagnose critical levels of anemia. In order to do this, we take advantage of Beer-Lambert’s Law – a physical law that states concentration scales linearly with absorbance (a measure of how much light a molecule can absorb at a given wavelength). With the use of a microfluidic device, whole blood flows through an 8 mm x 250 μm x 50 μm channel and is illuminated by a white LED. A portion of the light is then absorbed by hemoglobin and continues at a reduced intensity to a green filter to focus our measurements to the visible green spectra, because it is known that hemoglobin absorbs the most light at about 540 nm, which is in this region. We demonstrate that our devices can determine hemoglobin concentration effectively with less than 40 μL of blood and at a low cost. The immediate impact of hemoglobin measurements of small volumes is its use towards children. The long-term impact is a diagnostic point of care device to solve global needs.

Danon disease, a form of cardiomyopathy, results in deficient blood flow due to the weakening of heart muscles and can lead to a shortened lifespan. In collaboration with the Song lab at the University of Colorado, we aim to better understand the differences in contractile function between healthy cardiomyocytes and those from individuals with Danon disease. The Song lab obtained primary adult cells from two control groups—healthy individuals without cardiac problems—and three diseased groups—people suffering from Danon disease. The patient cells were used to generate induced pluripotent stem cells (iPSC), from which they derived cardiomyocytes that possess genetic information of the original donor. The Sniadecki lab has the technology to make micropost substrates from polydimethylsiloxane (PDMS), using a soft lithography process. The iPSC-cardiomyocytes were seeded onto the microposts. As the cardiomyocytes contract on the microposts, each post under the cell deflects. Videos were taken at the tips of the microposts underneath the beating cells, to record the post deflection over time. A still image was taken at the bottom of the microposts in order to determine the relative deflection of each post. From the deflection of the posts, we were able to measure contractile forces produced by the iPSC-cardiomyocytes using simple beam bending theory. For this experiment, we used microposts with following dimensions: height = 4.14 μm, diameter = 1.75 μm, and center-to-center spacing of 6 μm. These dimensions gave each post a stiffness = 56 nN/μm, which was used to calculate the force. We hypothesized that the diseased cells will produce lower contractile forces than the control cells. The results produced supported our hypothesis. We hope this study contributes to the effect of Danon disease on the contractile function of cardiomyocytes. Further, this work would exemplify a methodology to investigate cardiac disease modeling and treatments.

Vascular injury causes platelets to form hemostatic plugs. Platelets are activated by high shear and collagen, and adhere and contract to protect a clot from mechanical forces. The role of collagen and the anticoagulants heparin and ASA (Acetylsalicylic Acid), which inhibit thrombin and TxA2 (Thromboxane A2) respectively, are not fully understood. Our lab has designed a microfluidic device to measure clot forces and area. Microfluidic channels with block-post sensors generate shear gradients that induce platelet adhesion. Clots grow towards the post and contract, pulling the post closer. Fluorescence microscopy allows post deflection to be analyzed with MATLAB code using Hooke's Law, and phase images monitor area. First, channels were coated with and without collagen. Then, channels were collagen-coated and blood inhibited with heparin or ASA. Blood was incubated with 15 USP (U.S. Pharmacopeia standard) heparin lithium in H2O or 0.3 mM ASA in DMSO for 20 min. Clots in uncoated channels had lower forces than in collagen-coated channels. Blood with ASA in DMSO had less platelet adhesion and contraction than in blood incubated with DMSO. Blood with heparin in H2O had lower force but higher clot area than without heparin. Reduced force of clots formed in uncoated channels relative to collagen-coated channels suggests that collagen is important in force. Inability of platelets to adhere or produce normal force with ASA indicates that TxA2 promotes platelet aggregation and force. Heparin reduced force but not platelet aggregation, thus thrombin is involved in force generation only. This clot-on-a-chip technology can shed light on the clotting process and diagnose patient clotting issues.

One third of adults from ages 20 to 44 have untreated dental caries, typically treated through irreversible fillings and root canals (Centers for Disease Control and Prevention, 2012). Current technologies require professional consultation for caries detection – an inconvenient and costly process. Our objective is creating an optical system of detecting early caries formation to be performed at home on a weekly basis via spectral imaging of the plaque on teeth. The bacterial growth in plaque and demineralization of underlying enamel is detected by optically monitoring the fluorescent byproduct of bacterial metabolism, porphyrin. By imaging teeth in blue reflectance light and red fluorescence signal, concentration and growth of plaque deposits are measured using target versus background (T/B) pixel peak values (PPV) and T/B pixel count (PC) of PPV. Repeated measurements are plotted for plaque deposits and trends. Statistical analysis and comparison of T/B ratios and PCs trending can identify the most efficient measurement for locating plaque deposits most susceptible to caries development, prompting more efficient preventative care and triggering a dental examination. This new concept was simulated in vitro using a dental training model of teeth, measured applications of red stain, image stitching software (123D, Autodesk), image analysis software (ImageJ), and a mobile phone. Red stain was applied in increasing concentration and volume to both occlusal and interproximal crevasses that would most likely be missed by brushing and flossing. At each time period, a series of 2D images were acquired to reconstruct 3D models of simulated bacterial growth and were processed using ImageJ for T/B ratios of PPVs and PCs, which were plotted against each time period. T/B ratios of PPVs produced the most consistent measure of trending of the simulated growth, R^2 values 0.77, with statistically significant differences in variance with PC ratios (f-test).

Use of Computational Fluid Dynamics (CFD), as a design and investigation tool in fields of science and engineering, is rapidly increasing parallel to today’s rapid growth of economically affordable computational hardware and software resources. However, it is extremely important that methodological usages of CFD is established and taught to the current generation of engineers and scientists with an almost same pace compared to current evolution pace of CFD’s usage. Learning a goal-oriented and methodological approach to use CFD would guarantee a reliable, an efficient and economically feasible final engineering designs and products. The core idea of the current project (SFO Project) is to achieve this important task via developing and validating a family of CFD simulations for the most fundamental problems in field of Fluid Mechanics in three CFD packages. The steps of this development and validation process are documented in form of a goal-oriented and methodological approach and made publicly available for use and further development of young scientists and engineers on the web. As a cherry on top, the application of the developed CFD simulations to more complex and real-life problems will be addressed and investigated. The focus of the current presentation is on the CFD simulations development for the flow over a two-dimensional cylinder, as one of the most fundamental and applicable problem in field of Fluid Mechanics. The simulations were first developed for the laminar and steady flow over a cylinder (i.e. Reynolds < 200). The numerical results were compared and validated against previously published experimental and numerical results. These validated simulations are currently being used for simulation and investigation of unsteady laminar flow around a stationary and heated cylinder. In the end the potential application of these developed CFD simulations to the real life, scientific and engineering problems are addressed and investigated.

Cholangiocarcinoma, better known as bile duct cancer, is a rare and aggressive form of cancer in the biliary system. Bile duct cancer has the third lowest 5-year survival rate among all forms of cancer in the US. Due to its location, access to the biliary system for detection or diagnosis is difficult without invasive methods. Early detection of bile duct cancer is crucial and could be achieved by using the multimodal scanning fiber endoscope (SFE) developed in our lab. The SFE is able to noninvasively enter the biliary tree through the digestive system and present realistic information about the potential malignancies or disease state. Typically, a phantom is used to mimic the in-vivo presentation of disease state in order to validate the use of a new medical device. To prepare the SFE for this kind of cancer detection, a bile duct phantom with three dimensional (3D) cell culture was developed to test the sensitivity and specificity of the real-time in-vivo imaging. A biocompatible and optically clear polydimethylsiloxane (PDMS) device was first made for the cast of the hydrogel phantom. The device was utilized for structural stability of the phantom like a cast. The phantom was constructed by folding a flat sheet of hydrogel into a cylindrical tube with a lumen that reflects the true diameter of bile duct. The cancer cells were suspended at specific locations in order for spatial validation of SFE. The end result was the development of a 3D cell culture phantom with fluorescent probes targeted to cancer biomarkers. The phantom was imaged with SFE to evaluate its ability to accurately locate malignancies, distinguishing cancer cells from normal cells. Future work will extend to validation of fluorescent probes and ultimately lead to development of a new cancer imaging method with SFE to reduce late diagnosis.

Locomotion is a ubiquitous human behavior. The analysis of locomotion patterns is critical for diagnosing and monitoring musculoskeletal disorders. However, current analysis methods are limited to gait laboratories equipped with accurate optical systems and force plates. To address this limitation, this work focuses on developing a process for manufacturing low-cost, individualized, flexible foot insoles equipped with force, acceleration, and gyroscopic sensors. The approach is a three stage three-dimensional (3-D) printing process: (1) 3-D print flexible base layer with electronic compartments; (2) install electronics; and (3) 3-D print flexible closing top layer. The design of the insole with respect to the sensor location is highly modifiable, resulting in subject specific sensor layouts. Moreover, any miniaturized sensor/transducer can be incorporated in the design. The resulting structure is a flexible instrumented insole worn in the user's shoe. Currently, the main application is for real-time sensing for use with a bionic ankle prosthesis. Future applications include real-time sports analysis, sweat sensing for analysis of body chemistry, and energy conversion using piezo electric transducers. Thus, the main contribution of this work is a manufacturing process for low-cost flexible 3-D printed insoles with embedded sensors.

Pancreatic cancer is ranked fourth amongst the most lethal cancers in US and first in mortality due to its low five-year survival rate. Accurate, definitive diagnoses are determined by pathologists who visually inspect and evaluate tissue slices from patient-procured biopsies traditionally processed into 2D slides. 3D microscopy makes 3D pathology, consisting of the imaging, visualization, and evaluation of unsectioned tissue biopsies in 3D, become a reality. Similar to the advantages of CT over traditional X-ray, 3D pathology may enhance pancreatic cancer detection and further streamline the diagnostic process in pathology. However, similarities with traditional pathology in optical information needs to first be achieved in 3D pathology in order to pair with current skilled pathologists. Enough color contrast and resolution of intracellular and extracellular structures can provide desirable features of biopsies to pathologists. Hence 3D pathology project in Human Photonic Laboratory aims to accomplish this goal by performing staining, imaging, reconstruction, and 3D visualization for tissue biopsies. Preliminary result illustrates that the reconstruction algorithm with appropriate parameters based on frequency spectrum of data determines the resolution of reconstructed images. Specific 3D manipulation software Amira helps 3D visualization of reconstructed images and preserve color contrast using its colormapping feature. The investigation of proper colormapping protocol starts from colormapping in-silico image of processed 2D microscope slides. An imaging systems with designed image stitching program creates grayscale image of microscope slides. Spectrometer is used to take spectral reflectance measurement. A developing algorithm will take the data and calculate coordinate values of the specimen in color space of human vision. Those values will be used in Amira in colormapping for in-silico image of microscope slides to pair with full color image of slides. This colormapping technique has potentials to extend into unsectioned sample and hence combine with reconstruction algorithm to achieve colormapping for 3D visualization.

Dynamically modeling insect wings helps engineers understand the principles of flapping-wing MAVs (Micro-Aerial Vehicle). Due to its insect size and low visibility, flapping-wing MAVs are broadly used in surveillance missions, remote observation of hazardous environment and even artificial pollination. Although several MAVs have been successfully developed so far, there still exists a large space for engineers to optimize the design, such as reducing the weight, energy consumption and cost. Based on the biological evidence that the wing deformation is mainly caused by inertial-elastic forces rather than aerodynamic loads, we developed an inertial elastic deformable hawk moth’s fore-wing model. Using this model, we determined the instantaneous power consumption of the flapping wing by adding the time derivatives of kinetic and potential energies together. The model revealed that significant power is required to compensate for the wing elasticity. We are trying to apply this model to various insects’ wings with various length scales to compare their structural properties and look for universal trend of the change of instantaneous power output. We hypothesize the model can predict the power requirement more accurately at smaller length scale wings, because inertial force tends to dominate aerodynamic force in smaller flying insects.

People with leg amputations who use prosthetic feet during community ambulation encounter frequent environmental barriers. Uneven ground, such as grassy fields or sidewalks in disrepair, cause excessive forces at the interface between the artificial leg and the residual limb because of torques from the ground acting on the foot. These forces can cause pain, skin breakdown, and falls. Impulsive forces may be reduced by a prosthetic foot allowing medial-lateral rotation of the foot relative to the leg. This study compared the kinetic and kinematic outcomes of an investigational prosthetic (IP) foot to the participant’s usual prostheses. Eight study participants completed a single leg balance test and 5 walking conditions with their prescribed prosthetic (UF) and with the IP foot. The participants walked lengthwise along 10% and 15% side slopes and across domes (Botts’ dots) placed on flat ground. A 3-D motion capture system tracked 36 reflective dots which were placed on key landmarks so that joint angles and spatiotemporal metrics could be computed. One participant’s data was excluded from the ankle joint outcomes. Participants reported reduced forces at the residual limb-prosthesis interface. Preliminary results indicated that the UF and IP foot perform similarly in sagittal plane motion. The IP foot increased the ankle medial-lateral rotation for 5 out of 6 participants. Future research will include comparing a participant’s UF to the IP foot in community trials while collecting activity monitoring, GPS, and logbook data.