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- Qin, Chunxia, et al.
(författare)
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An oral and maxillofacial navigation system for implant placement with automatic identification of fiducial points
- 2019
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Ingår i: International Journal of Computer Assisted Radiology and Surgery. - : SPRINGER HEIDELBERG. - 1861-6410 .- 1861-6429. ; 14:2, s. 281-289
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Tidskriftsartikel (refereegranskat)abstract
- PurposeSurgical navigation system (SNS) has been an important tool in surgery. However, the complicated and tedious manual selection of fiducial points on preoperative images for registration affects operational efficiency to large extent. In this study, an oral and maxillofacial navigation system named BeiDou-SNS with automatic identification of fiducial points was developed and demonstrated.MethodsTo solve the fiducial selection problem, a novel method of automatic localization for titanium screw markers in preoperative images is proposed on the basis of a sequence of two local mean-shift segmentation including removal of metal artifacts. The operation of the BeiDou-SNS consists of the following key steps: The selection of fiducial points, the calibration of surgical instruments, and the registration of patient space and image space. Eight cases of patients with titanium screws as fiducial markers were carried out to analyze the accuracy of the automatic fiducial point localization algorithm. Finally, a complete phantom experiment of zygomatic implant placement surgery was performed to evaluate the whole performance of BeiDou-SNS. Results and conclusionThe coverage of Euclidean distances between fiducial marker positions selected automatically and those selected manually by an experienced dentist for all eight cases ranged from 0.373 to 0.847mm. Four implants were inserted into the 3D-printed model under the guide of BeiDou-SNS. And the maximal deviations between the actual and planned implant were 1.328mm and 2.326mm, respectively, for the entry and end point while the angular deviation ranged from 1.094 degrees to 2.395 degrees. The results demonstrate that the oral surgical navigation system with automatic identification of fiducial points can meet the requirements of the clinical surgeries.
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| 2. |
- Wang, Chengliang, et al.
(författare)
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Hybrid-cavity fabry-perot interferometer for multi-point relative humidity and temperature sensing
- 2018
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 255, s. 1937-1944
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Tidskriftsartikel (refereegranskat)abstract
- A novel hybrid-cavity Fabry-Perot interferometer (HFPI) is theoretically proposed and experimentally demonstrated. The hybrid micro-cavity structure is consisted of a short segment of four-hole suspended-core fiber (SCF) and attaching moderate optical adhesive as the hygroscopic material. Due to the different sensitivities of the hybrid Fabry-Perot (F-P) cavities to the relative humidity (RH) and temperature, both information can be simultaneously demodulated by utilizing the phase-shift tracking scheme in the Fast Fourier Transform (FFT) spectra. The precise micromanipulation of each cavity length ensures the separation of each amplitude peak in the FFT spectra, which renders this HFPI multi-point sensing capability. Experimental tests were carried out, and the results indicate that the proposed HFPI with excellent sensing performance is a promising platform for multi-point RH and temperature sensing applications.
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| 3. |
- Wu, Shengnan, et al.
(författare)
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An open-cavity Fabry-Perot interferometer with PVA coating for simultaneous measurement of relative humidity and temperature
- 2016
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Ingår i: Sensors and actuators. B, Chemical. - : ELSEVIER SCIENCE SA. - 0925-4005 .- 1873-3077. ; 225, s. 50-56
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Tidskriftsartikel (refereegranskat)abstract
- A fiber-optic open-cavity Fabry-Perot (FP) interferometer (FPI) with polyvinyl alcohol (PVA) coating is proposed and experimentally demonstrated for simultaneous measurement of relative humidity (RH) and temperature. The FPI consists of an etched side-hole fiber (SHF) sandwiched in between two leading single-mode-fibers. The PVA film is plated on the fiber surface functioning as a humidity-to-refractive index (RI) transducer. Theoretical analysis details the RH and temperature influence on the spectral fringes of the FPI. Experimental results confirms and show that, the reflection loss of the FPI nonlinearly decreases more than 15 dB when the RH increases from 30%RH to 90%RH with a highest sensitivity of -1.2 dB/%RH, while the dip wavelength of the spectral fringe exhibits linear RH and temperature sensitivities of -23.1 pm/%RH and -6.14 pm/degrees C, respectively. Thus, by monitoring the reflection and wavelength of the interference dip, the proposed sensor enables accurate simultaneous measurement of RH and temperature. A fast and reversible time response has also been demonstrated. Such excellent sensing performance with compactness, ease of fabrication makes our sensing structure a highly promising candidate for RH and temperature monitoring applications.
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