Journal of Biomedical Engineering Research (대한의용생체공학회:의공학회지)

The Korean Society of Medical and Biological Engineering (대한의용생체공학회)
권호 표지
DOI QR코드

DOI QR Code

Accuracy Evaluation of Bi-medium Deep Body Thermometer Based on Finite Element Simulation

유한 요소 시뮬레이션을 이용한 이중 매질 심부 체온계의 정확도 평가

  • Sim, S.Y. (Interdisciplinary Program of Bioengineering, College of Engineering, Seoul National University) ;
  • Ryou, H.S. (Interdisciplinary Program of Bioengineering, College of Engineering, Seoul National University) ;
  • Kim, H.B. (Interdisciplinary Program of Bioengineering, College of Engineering, Seoul National University) ;
  • Jeong, J.H. (Department of Medical Biotechnology, College of Life Science and Biotechnology, Dongguk University) ;
  • Lee, S.J. (Department of Information and Communication Engineering, Sunmoon University) ;
  • Kim, S.M. (Department of Medical Biotechnology, College of Life Science and Biotechnology, Dongguk University) ;
  • Park, Kwang Suk (Department of Biomedical Engineering, College of Medicine, Seoul National University)
  • 심수영 (서울대학교 공과대학 바이오엔지니어링 협동과정) ;
  • 유호석 (서울대학교 공과대학 바이오엔지니어링 협동과정) ;
  • 김한별 (서울대학교 공과대학 바이오엔지니어링 협동과정) ;
  • 정재훈 (동국대학교 의생명공학과) ;
  • 이상준 (선문대학교 정보통신공학과) ;
  • 김성민 (동국대학교 의생명공학과) ;
  • 박광석 (서울대학교 의과대학 의공학교실)
  • Received : 2014.07.28
  • Accepted : 2014.10.14
  • Published : 2014.10.31
Download PDF
⟨ Previous Next ⟩

Abstract

Continuous body temperature monitoring is useful and essential in diverse medical procedures such as infection onset detection, therapeutic hypothermia, circadian rhythm monitoring, sleep disorder assessment, and gynecological research. However, the existing thermometers are too invasive or intrusive to be applied to long-term body temperature monitoring. In our previous study, we invented the bi-medium deep body thermometer which can noninvasively and continuously monitor deep tissue temperature. And the ratio of thermal resistances expressed as K-value should be obtained to estimate body temperature with the thermometer and it can be different under various measurement environments. Although the device was proven to be useful through preliminary simulation test and small group of human study, the experimental environment was restrictive in our previous approach. In this study, a finite element simulation was executed to obtain the K-value and evaluate the accuracy of bi-medium thermometer under various measurement environments. In addition, K-value estimation equation was developed by analyzing the influence of 5 measurement environmental factors (medium length, medium height, tissue depth, blood perfusion rate, and ambient temperature) on K-value. The results revealed that the estimation accuracy of bi-medium deep body thermometer based on computer simulation was very high (RMSE < $0.003^{\circ}C$) in various measurement environments. Also, bi-medium deep body thermometer based on K-value estimation equation showed relatively accurate results (RMSE < $0.3^{\circ}C$) except for one case. Although the K-value estimation technology should be improved for more accurate body temperature estimation, the results of finite element simulation showed that bi-medium deep body thermometer could accurately measure various tissue temperatures under diverse environments.

Keywords

References

  1. Davidovits P., Physics in biology and medicine, London, UK: Academic press, 2007, pp. 145
  2. D.S. Moran, S.J. Montain, and K.B. Pandolf, "Evaluation of different levels of hydration using a new physiological strain index," Am. J. Physiol. Regul. Integr. Comp. Physiol., vol. 275, no. 3, pp. R854-R860, 1998. https://doi.org/10.1152/ajpregu.1998.275.3.R854
  3. D. Darwent, et al., "The validity of temperature-sensitive ingestible capsules for measuring core body temperature in laboratory protocols," Chronobiol. Int., vol. 28, no. 8, pp. 719-726, 2011. https://doi.org/10.3109/07420528.2011.597530
  4. F.C. Baker, et al., "Sleep and 24 hour body temperatures: a comparison in young men, naturally cycling women and women taking hormonal contraceptives," J. Physiol., vol. 530, no. 3, pp. 565-574, 2001. https://doi.org/10.1111/j.1469-7793.2001.0565k.x
  5. K.G. Ng, et al., "Evaluation of the Cadi ThermoSENSOR Wireless Skin-Contact Thermometer Against Ear and Axillary Temperatures in Children," J. Pediatr. Nurs., vol. 25, no. 3, pp. 176-186, 2010. https://doi.org/10.1016/j.pedn.2008.12.002
  6. H.C. GUNGA, et al., "A new non-invasive device to monitor core temperature on earth and in space," Ann. Kinesiol., vol. 3, no. 1, pp. 47-60, 2012.
  7. R.H. Fox and A.J. Solman, "A new technique for monitoring the deep body temperature in man from the intact skin surface," J. Physiol., vol. 212, no. 2, pp. 8-10, 1971.
  8. K, Kitamura, et al., "Development of a new method for the noninvasive measurement of deep body temperature without a heater," Med. Eng. Phys., vol. 32, no. 1, pp. 1-6, 2010. https://doi.org/10.1016/j.medengphy.2009.09.004
  9. Huang, M., Chen, W., "Theoretical simulation of the dualheat- flux method in deep body temperature measurements," in 32nd Conf. Proc. IEEE Eng. Med. Biol. Soc., Buenos Aires, Argentina, August. 2010, pp. 561-564.
  10. S.Y. Sim, et al., "Simulation study of a newly designed structure for monitoring deep body temperature," in Proc. 9th Intern. Conf. Ubiquitous Healthcare, Gyeongju, Korea, October. 2012.
  11. S.Y. Sim, et al., "Accuracy evaluation of noninvasive and nonintrusive body temperature monitor," in Proc. 47th conference of the KOSOMBE, Gumi, Korea, May. 2013, pp. 63-64.
  12. J.P. Holman, Heat transfer 6th Edition, New York, USA: McGraw, 1986, pp. 27-29.
  13. H.H. Pennes, "Analysis of tissue and arterial blood temperatures in the resting human forearm," J. Appl. Physiol., vol. 85, no. 1, pp. 5-34, 1998. https://doi.org/10.1152/jappl.1998.85.1.5
  14. Properties of non-metal, http://ottp.fme.vutbr.cz/predmety/thermomechanics/therm_ prop_non-met.pdf (accessed July. 28, 2014).
  15. M. Masaru, et al., "Non-invasive monitoring of core body temperature rhythms over 72h in 10 bedridden elderly patients with disorders of consciousness in a Japanese hospital: A pilot study," Arch. Gerontol. Geriatr., vol. 57, no. 3, pp. 428-432, 2013. https://doi.org/10.1016/j.archger.2013.05.009
  16. Zhu, L., and C. Diao., "Theoretical simulation of temperature distribution in the brain during mild hypothermia treatment for brain injury," Med. Biol. Eng. Comput., vol. 39, no. 6, pp. 681-687, 2001. https://doi.org/10.1007/BF02345442
  17. I.A. Brezovich, J.H. Young, and M.T. Wang. "Temperature distributions in hyperthermia by electromagnetic induction: a theoretical model for the thorax," Med. Phys., vol. 10, no. 1, pp. 57-65, 1983. https://doi.org/10.1118/1.595376
  18. H.L. Staniak, et al., "Subcutaneous tissue thickness is an independent predictor of image noise in cardiac CT," Arq. Bras. Cardiol., vol. 102, no. 1 pp. 86-92, 2014.