Optical Fiber Grating Characterization for Haptic Sensors in Minimally Invasive Diagnostics and Surgery

点击翻译按钮获取中文摘要

Each day in the United States, on average, 30 women die of ovarian cancer and 80 men of prostate cancer. There is a 55% greater incidence of prostate cancer in black men than in white men. A major obstacle in the fight against these cancers is conclusive early detection. Minimally invasive diagnostics provide a potential solution to this problem. However, without a sense of feel (haptic) of the relevant bodily region, the medical professional cannot make a complete informed diagnosis. This leads to lower efficacy and increased danger in some cases when compared to traditional techniques. To overcome this deficiency, fiber gratings can potentially be used as haptic feedback sensors to provide the otherwise missing sense of feeling in minimally invasive procedures. However, this promising approach is being stymied by a lack of clear information on the detailed designs needed and how to measure and verify quantitatively that the required fabrication has been achieved. Until the present, the approach to fabricate these sensors has been very rudimentary in nature. This research project takes a major step in quantitatively measuring the physical characteristics of fiber gratings and then correlating them with the needed haptic sensing capabilities. This research is directed toward expanding the safety and efficacy of minimally invasive procedures. Further, there is a significant additional dividend coming from this research. Namely, the present methodology could also be used in subsequent surgical procedures if such procedures are indicated based on the diagnostic results. Overall, this research is directed toward more accurate diagnostic procedures based on a quantitative understanding of fiber gratings and their quantitative use as haptic sensors in medical practice. This research project incorporates numerous female and minority students. Namely, 1) a program with Agnes Scott College (women's college) to provide research experiences in micro-fabrication and quantitative phase imaging,2) the NSF-funded Summer Undergraduate Research in Engineering/Science (SURE) program that gives minorities exposure to on-line journals and library databases, reference management software, and successful research approaches in quantitative phase imaging.TechnicalOvarian and prostate cancers are challenging to diagnose at their early stages. More effective diagnosis for these cancers would obviously enable improved techniques for other cancers and medical conditions as well. Minimally invasive diagnostics provide a potential solution for this problem. However, these diagnostic techniques largely lack a sense of feel (haptic) for the medical professional. Fiber optic grating sensors can potentially provide the needed haptic feedback. However, at the present time, it is not known what detailed fiber grating designs are needed and how to measure and verify quantitatively the fabricated structures. In order to address this deficiency, the goal of this research project is to apply quantitative phase imaging (QPI) to develop methodologies that will characterize concurrently the refractive index distributions and residual stress distributions in fiber gratings. The new methods being developed in this research project are extensions of the tomographic deconvolution phase microscopy (TDPM) approach conceived and first implemented at Georgia Tech. Fiber configurations to be treated include 1) single gratings in single fibers, 2) multiple gratings in multiple combined fibers, and 3) multiple gratings in multi-core fibers. These measurements represent the first concurrent determination of the cross-sectional refractive-index and stress distributions at the proposed high level of accuracy and high spatial resolution. The fiber Bragg gratings (FBGs) and long-period fiber gratings (LPFGs) formed by various processes are further being analyzed to provide insights into the effects of fabrication on the performance of these gratings as a haptic feedback sensors.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.