Non-invasive Assessments of Cutaneous Injury Caused by High Voltage Electrical Injury: Experiments and Simulations

URI / Handle

Research on tissue injury following high-voltage shock is needed and helps reduce amputation rate. This thesis performed an overall assessment, on pathophysiological and thermal responses, of skin under different dosages of direct-current high-voltage electrical shock, through experiments and simulations.In vivo experiments were conducted to investigate the viability of rat skin tissues distant to the wounds following 1,000 VDC at 2, 4, 8, and 20 seconds. Electrical injuries were created with an accurate custom-made shock system. A Spatial Frequency Domain Imaging (SFDI) system was built to assess physiological parameters of the skin tissues, including tissue oxygen saturation (SO2), met-hemoglobin volume fraction (MetHB), and hemoglobin volume fraction (HB). After shocks, all groups showed increases in HB and MetHB, and decreases in SO2. Especially, a significant reduction of SO2 and a remarkable build-up of MetHB were found in 20-second group, revealing an irreversible skin damage and blood stasis. This correlated to the descent of blood perfusion, measured by a Laser Doppler Imaging machine.Additionally, a novel finite element model was successfully generated to simulate similar shocks on a 3D rat, including major internal organs with temperature-dependent blood perfusions. Simulation and experimental skin temperature showed a good match, with <5% of percentage error. Skin thermal damage calculation indicated a 2nd degree burn in 20-second group. Predicted tissue damage combined with pathophysiological changes provides a systemic explanation for high-voltage electrical injury. The model also allows evaluating thermal damage of other tissues.This novel application of SFDI in burn wound assessment was utilized to recognize infected burn wounds in a controlled in vivo rat model. Statistical calculation showed significant differences in optical properties between infected and controlled groups from day 4 (p<0.05). This work will help in early detection of burn wound infection to reduce systemic complications. In this thesis, I also proposed a novel practical correction method aimed at minimizing the limitation of SFDI in imaging curved surfaces. This method applied a 3D printing technique combined with an accurate 3D imaging method for phantom reconstruction with any shape. Phantom tests showed remarkable improvements especially for complex structures. This can also be applied to other spectral imaging modalities.
Details
Title

Non-invasive Assessments of Cutaneous Injury Caused by High Voltage Electrical Injury: Experiments and Simulations

Contributors

Ramella-Roman, Jessica C. (Advisor); Nguyen, Thu Thi Anh (Author); Mathews, Scott A. (Other); Shupp, Jeffrey W. (Other); Wang, Zhaoyang (Other)

Degree Information

Degree awarded: Ph.D. Electrical Engineering and Computer Science. The Catholic University of America

Extent

186 p.

URI / Handle

http://hdl.handle.net/1961/15318

Advisor

Ramella-Roman, Jessica C.

Other

Mathews, Scott A.; Shupp, Jeffrey W.; Wang, Zhaoyang

Subject

Electrical engineering; Biomedical engineering; 3D reconstruction; Electrical Cutaneous Injury Assessment; Finite Element model; Optical Imaging

Accessioned

2014-02-11T18:36:03Z

Available

2014-02-11T18:36:03Z

Created

2014-01-01T00:00:00Z

Issued

2014-02-11T00:00:00Z

Abstract

Research on tissue injury following high-voltage shock is needed and helps reduce amputation rate. This thesis performed an overall assessment, on pathophysiological and thermal responses, of skin under different dosages of direct-current high-voltage electrical shock, through experiments and simulations.In vivo experiments were conducted to investigate the viability of rat skin tissues distant to the wounds following 1,000 VDC at 2, 4, 8, and 20 seconds. Electrical injuries were created with an accurate custom-made shock system. A Spatial Frequency Domain Imaging (SFDI) system was built to assess physiological parameters of the skin tissues, including tissue oxygen saturation (SO2), met-hemoglobin volume fraction (MetHB), and hemoglobin volume fraction (HB). After shocks, all groups showed increases in HB and MetHB, and decreases in SO2. Especially, a significant reduction of SO2 and a remarkable build-up of MetHB were found in 20-second group, revealing an irreversible skin damage and blood stasis. This correlated to the descent of blood perfusion, measured by a Laser Doppler Imaging machine.Additionally, a novel finite element model was successfully generated to simulate similar shocks on a 3D rat, including major internal organs with temperature-dependent blood perfusions. Simulation and experimental skin temperature showed a good match, with <5% of percentage error. Skin thermal damage calculation indicated a 2nd degree burn in 20-second group. Predicted tissue damage combined with pathophysiological changes provides a systemic explanation for high-voltage electrical injury. The model also allows evaluating thermal damage of other tissues.This novel application of SFDI in burn wound assessment was utilized to recognize infected burn wounds in a controlled in vivo rat model. Statistical calculation showed significant differences in optical properties between infected and controlled groups from day 4 (p<0.05). This work will help in early detection of burn wound infection to reduce systemic complications. In this thesis, I also proposed a novel practical correction method aimed at minimizing the limitation of SFDI in imaging curved surfaces. This method applied a 3D printing technique combined with an accurate 3D imaging method for phantom reconstruction with any shape. Phantom tests showed remarkable improvements especially for complex structures. This can also be applied to other spectral imaging modalities.

Type

Text; Dissertation

Local

Nguyen_cua_0043A_10461

Publisher

The Catholic University of America

Publish Date

2014-02-11

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