Biomedical subjects

Shengyi Li

Publications and source records attributed to Shengyi Li.

4 recordsLinked to original sources

PubMed2006

Lattice design for subaperture stitching test of a concave paraboloid surface.

Lattice design is subtle and complicated for the subaperture stitching test of aspheric surfaces. Methods are described in this paper for the collection and arrangement of subapertures, and calculation of the best-fit sphere for each subaperture. The best-fit sphere is determined by minimizing the mean-square aspheric deviations in the form of a surface integral. Finally, a numerical example is given to illustrate the procedure, and also to verify the validity of our proposed methods.

Journal Article↗

PubMed2006

Iterative algorithm for subaperture stitching test with spherical interferometers.

Recently we have proposed an iterative algorithm for subaperture stitching interferometry. It was referred to as the subaperture stitching and localization (SASL) algorithm. The limitation of the algorithm is that three-dimensional Cartesian coordinates are required, whereas the standard spherical interferometer can read out only the phase differences on the pixels. On the basis of the SASL algorithm, we propose an iterative algorithm for a spherical subaperture stitching test. It deals with data directly from the spherical interferometer. Unknown radii of best-fit spheres for a null test of subapertures are included in the optimization variables. The developed algorithm inherits the advantages of the SASL algorithm.

Journal Article↗

PubMed2005

Iterative algorithm for subaperture stitching interferometry for general surfaces.

A novel iterative algorithm for subaperture stitching interferometry for general surfaces is presented. It is based on the alternating optimization technique and the successive linearization method. The computer-aided-design model of the tested surface is used to determine the overlapping region precisely. Subapertures are simultaneously stitched by minimizing deviations among them as well as deviations from the nominal surface. Precise prior knowledge of the six degrees-of-freedom nulling and alignment motion is no longer required.

Journal Article↗

PubMed2002

[Combined high dose leucovorin and 5-fluorouracil continuous infusion for head-neck and digestive tract cancers].

OBJECTIVE: To evaluate the feasibility of combined high dose leucovorin plus 5-fluorouracil infusion for head-neck and digestive tract cancers. METHODS: Fifty-six patients with head-neck and digestive tract cancer were treated by combined high dose leucovorin (HD-CF) plus 5-fluorouracil (5-Fu) 48 hour continuous infusion with each patient receiving an average of 3.8 cycles (2-6 cycles). Twenty-five of these 56 patients were untreated and 31 recurrent. Their clinical stages were II 4, III 13 and IV 39. RESULTS: The over all response rate (CR + PR) was 35.7% and the clinical beneficial response rate was 80.4%. The main side effects were peripheral phlebitis, suppression of bone marrow, oral ulcer, nausea and vomiting of grade I to II. CONCLUSION: High dose leucovorin plus 5-fluorouracil 48 hour continuous infusion is useful with favorable cost/utility ratio for head-neck and digestive tract cancer patients. Further studies are warranted.

Adult↗