Small-diameter shape sensors have a variety of potential applications in medicine such as the positioning of breast tumor chest needles
shape display of intestinal endoscopes
and positioning of cardiac vascular catheters. The shape-reconstruction and end-positioning accuracies of shape sensors have always been major concerns of researchers. To improve the shape-reconstruction accuracy of a fiber Bragg grating (FBG) shape sensor
the strain transfer law of an FBG shape sensor with 90° distribution of fiber around the center of the substrate was studied and verified experimentally. Epoxy resin glues the FBG to the surface of the nickel-titanium alloy wire to form a four-layer structure of the substrate-bonding layer-fiber-bonding layer of the FBG shape sensor. Based on a simplified model of strain transmission mechanics of the FBG sensor
the corresponding average strain transfer rate formula was derived. The effects of the fiber-to-substrate center distance
bond layer length
thickness
and elastic modulus on the average strain transfer rate of FBG sensors were also analyzed and experimentally verified. Experimental results show that the average strain transmission rate of the packaged FBG sensor increases with increasing substrate length in the effective range
whereas an increase in the outer diameter of the bond layer has little effect on the average strain transmission rate
thus verifying the applicability of the theoretical model. The strain transfer rate is introduced into the shape reconstruction
and the shape-reconstruction accuracy of the FBG shape sensor is reduced from 3.5% to 2.7%.
HAO W Y, CHEN Y T, SHAO G L. Clinical application of IG4 electromagnetic navigation system-assisted CT-guided percutaneous needle biopsy of pulmonary nodules[J]. Journal of Interventional Radiology , 2016, 25(8): 682-685. (in Chinese)
LI Q T, ZHOU S, YUAN M, et al .. Preliminary application of MRI-navigation system in assisting the performance of percutaneous biopsy[J]. Journal of Interventional Radiology , 2017, 26(3): 263-265. (in Chinese)
LEON M B, SMITH C R, MACK M, et al .. Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery[J]. Survey of Anesthesiology , 2011, 55(3): 112-113.
ZHANG L W, QIAN J W, ZHANG Y N, et al .. On SDM/WDM FBG sensor net for shape detection of endoscope[C]// IEEE International Conference Mechatronics and Automation , 2005, Niagara Falls , Ont ., Canada . New York , USA : IEEE , 2005, 4: 1986-1991.
ZHOU ZH, WANG Q, HAO X W, et al .. Strain transfer analysis of the FBG sensor considering the creep of the concrete host[J]. China Measurement & Test , 2016, 42(5): 1-5, 32. (in Chinese)
ZHAO B, ZHONG ZH CH, LIN J, et al .. Monitoring method and experiment for stratum stress based on fiber Bragg grating sensing[J] .Opt. Precision Eng ., 24(10s):346-352. (in Chinese)
ZHANG ZH L, WANG Y, SUN Y Y, et al .. Analysis and experimental study on the strain transfer mechanism of an embedded basalt fiber-encapsulated fiber Bragg grating sensor[J]. Optical Engineering , 2017, 56(1): 017105.
LI H, ZHU L Q, DONG M L, et al .. Analysis on strain transfer of surface-bonding FBG on Al 7075-T6 alloy host[J]. Optik , 2016, 127(3): 1233-1236.
HUANG X D, WANG Y, SUN Y Y, et al .. Mechanism analysis on the impact of coating to fiber Bragg grating strain transfer[J]. Chinese Journal of Scientific Instrument , 2016, 37(6): 1233-1240. (in Chinese)
WU R J, FU K K, ZHENG B L, et al .. Error modification of FBG strain sensors bonded on plates[J]. Opt. Precision Eng ., 2016, 24(4): 747-755. (in Chinese)
WU R J, ZHENG B L, CHEN T, et al .. Coupled mechanism analysis of strain transfer of fiber Bragg grating sensors[J] . Acta Photonica Sinica , 2017, 46(10): 49-58. (in Chinese)
SUN B CH, HOU Y M, LI F, et al .. Coupling characteristics between fiber grating and stimulated Brillouin signal[J]. Chinese Optics , 2017, 10(4): 484-490. (in Chinese)
HILL K O, MELTZ G. Fiber Bragg grating technology fundamentals and overview[J]. Journal of Lightwave Technology , 1997, 15(8): 1263-1276.
SHEN L Y, XIAO H, QIAN J W, et al .. Shape reconstruction and visualization of intelligent endoscope[J]. Chinese Journal of Scientific Instrument , 2014, 35(12): 2725-2730. (in Chinese)