Filtering by
- All Subjects: Biomedical Engineering
The flexible x-ray detector technology was then extended to demonstrate the viability of a new technique to seamlessly combine multiple smaller flexible x-ray detectors into a single very large, ultimately human sized, composite x-ray detector for new medical imaging applications such as single-exposure, low-dose, full-body digital radiography. Also explored, is a new approach to increase the sensitivity of digital x-ray detectors by selectively disabling rows in the active matrix array that are not part of the imaged region. It was then shown how high-resolution, flexible, organic light-emitting diode display (OLED) technology can be used to selectively stimulate and/or silence small groups of neurons on the cortical surface or within the deep brain as a potential new tool to diagnose and treat, as well as understand, neurological diseases and conditions. This work also explored the viability of a new miniaturized high sensitivity fluorescence measurement-based lab-on-a-chip optical biosensor using OLED display and a-Si:H PiN photodiode active matrix array technology for point-of-care diagnosis of multiple disease or pathogen biomarkers in a low cost disposable configuration.
The current clinical gold standards for tissue sealing include sutures, staples, and glues, however several adverse effects limit their use. Sutures and staples inherently cause additional trauma to tissue surrounding the wound, and glues can be lacking in adhesion and are potentially inflammatory. All three also introduce risk of infection. Light-activated tissue sealing, particularly the use of near-infrared light, is an attractive alternative, as it localizes heat, thereby preventing thermal damage to the surrounding healthy tissue. Previous work identified a glutaraldehyde-crosslinked chitosan film as a lead sealant for gastrointestinal incision sealing, but in vivo testing resulted in tissue degradation in and around the wound. The suggested causes for this degradation were excess acetic acid, endotoxins in the chitosan, and thermal damage. A basic buffer wash protocol was developed to remove excess acid from the films following fabrication. UV-Vis spectroscopy demonstrated that following the wash, films had the same concentration of Indocyanine green as unwashed films, allowing them to absorb light at the same wavelength, therefore showing the wash did not affect the film’s function. However subsequent washes led to degradation of film mass of nearly 20%. Standard chitosan films had significantly greater mass gain (p = 0.028) and significantly less subsequent loss (p= 0.012) than endotoxin free chitosan-films after soaking in phosphate buffered saline for varying durations , while soaking duration had no effect (p = 0.332). Leak pressure testing of films prepared with varying numbers of buffer washes, laser temperature, and lasering time revealed no significant interaction between any of the 3 variables. As such, it was confirmed that proceeding with in vivo testing with the buffer wash, various lasering temperatures, and laser times would not affect the sealing performance of the films. Future investigation will involve characterization of additional materials that may be effective for sealing of internal wounds, as well as drug loading of agents that may hasten the healing process.