View full-text article in PMC Sensors (Basel). 2016 Jun 1;16(6):807. doi: 10.3390/s16060807 Search in PMC Search in PubMed View in NLM Catalog Add to search Copyright and License information © 2016 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/). PMC Copyright notice b1=−k1 b2=3k12−k2 b3=−12k13+8k1k2−k3 b4=55k14−55k12k2+5k22+10k1k3−k4 b5=−273k15+364k13k2−78k1k22−78k12k3+12k2k3+12k1k4 b6=1428k16−2380k14k2+840k12k22−35k23+560k13k3−210k1k2k3+7k32−105k12k4+14k2k4 b7=−7752k17+15504k15k2−7752k13k22+816k1k23−3876k14k3+2448k12k2k3−136k22k3−136k1k32+816k13k4−272k1k2k4+16k3k4 b8=43263k18−100947k16k2+65835k14k22−11970k12k23+285k24+26334k15k3−23940k13k2k3+3420k1k22k3+1710k12k32−171k2k32−5985k14k4+3420k12k2k4−171k22k4−342k1k3k4+9k42 b9=−246675k19+657800k17k2−531300k15k22+141680k13k23−8855k1k24−177100k16k3+212520k14k2k3−53130k12k22k3+1540k23k3−17710k13k32+4620k1k2k32−70k33+42504k15k4−35420k13k2k4+4620k1k22k4+4620k12k3k4−420k2k3k4−210k1k42