Determining the emissivity of pig skin for accurate infrared thermography

Soerensen, Dennis Dam; Clausen, Sønnik; Mercer, James B.; Pedersen, Lene Juul

doi:10.1016/j.compag.2014.09.003

Cited by 84 publications

(67 citation statements)

References 25 publications

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“…An infrared camera (Mikron M7500; Hancock, MI) was positioned above the sample and additional thermocouples (Model IT-18; Physitemp ;Clifton, NJ) were placed on the tissue surface approximately 5 cm from antenna (outside heated zone) to calibrate temperature values derived from the IR camera. We assumed tissue emissivity of 0.9 [27]. The tissue surface temperature was recorded via IR camera (~3.3 fps, 320×240 resolution) for the duration of the experiment and the image sequence was stored for later image analysis.…”

Section: Methodsmentioning

confidence: 99%

Experimental measurement of microwave ablation heating pattern and comparison to computer simulations

Deshazer

Prakash

Merck

et al. 2016

International Journal of Hyperthermia

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Introduction For computational models of microwave ablation (MWA), knowledge of the antenna design is necessary, but the proprietary design of clinical applicators is often unknown. We characterized the specific absorption rate (SAR) during MWA experimentally and compared to a multi-physics simulation. Methods An infrared (IR) camera was used to measure SAR during MWA within a split ex vivo liver model. Perseon Medical’s short-tip (ST) or long-tip (LT) MWA antenna were placed on top of a tissue sample (n=6), and microwave power (15W) was applied for 6 min, while intermittently interrupting power. Tissue surface temperature was recorded via IR camera (3.3 fps, 320×240 resolution). SAR was calculated intermittently based on temperature slope before and after power interruption. Temperature and SAR data were compared to simulation results. Results Experimentally measured SAR changed considerably once tissue temperatures exceeded 100 °C, contrary to simulation results. The ablation zone diameters were 1.28 cm and 1.30 ± 0.03 cm (transverse), and 2.10 cm and 2.66 ± −0.22 cm (axial), for simulation and experiment, respectively. The average difference in temperature between the simulation and experiment were 5.6 °C (ST) and 6.2 °C (LT). Dice coefficients for 1000 W/kg SAR iso-contour were 0.74 ± 0.01 (ST) and 0.77 (± 0.03) (LT), suggesting good agreement of SAR contours. Conclusion We experimentally demonstrated changes in SAR during MWA ablation, which were not present in simulation, suggesting inaccuracies in dielectric properties. The measured SAR may be used in simplified computer simulations to predict tissue temperature when the antenna geometry is unknown.

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Section: Methodsmentioning

confidence: 99%

Experimental measurement of microwave ablation heating pattern and comparison to computer simulations

Deshazer

Prakash

Merck

et al. 2016

International Journal of Hyperthermia

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“…Animals were manually held and filmed at a constant distance (0.35 m). The animal emissivity was set to 0.98 and the tumor borders were marked to overlap with a visible image [29]. Representative frames were selected and analyzed using the ThermaCam Researcher Pro 2.10 (FLIR Systems, Inc., USA) software.…”

Section: Thermographic Evaluationmentioning

confidence: 99%

Long-term exercise training as a modulator of mammary cancer vascularization

Faustino-Rocha

Silva

Gabriel

et al. 2016

Biomedicine & Pharmacotherapy

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Background: Breast cancer remains a leading cause of death by cancer worldwide. It is commonly accepted that angiogenesis and the expression of angiogenic factors such as vascular endothelial growth factor-A (VEGF-A) is associated with the increased risk of metastasis and poor patient outcome.Objective: This work aimed to evaluate the effects of long-term exercise training on the growth and vascularization of mammary tumors in a rat model. Materials and methods:Fifty female Sprague-Dawley rats were divided into four groups: two N-methyl-N-nitrosourea (MNU)-exposed groups (exercised and sedentary) and two control groups (exercised and sedentary). MNU was administered once, intraperitoneally at 7 weeks-old. Animals were then exercised on a treadmill for 35 weeks. Mammary tumors were evaluated using thermography, ultrasonography [Power Doppler (PDI), B Flow and contrast-enhanced ultrasound (CEUS)], and immunohistochemistry (VEGF-A).Results: Both, MNU sedentary and exercised groups showed 100% of tumor incidence, but exercised animals showed less tumors with an increased latency period. Exercise training also enhanced VEGF-A immunoexpression and vascularization (microvessel density, MVD) (p < 0.05), and reduced histological aggressiveness. Ultrasound and 2 -thermal imaging analysis confirmed the enhanced vascularization of tumors on exercised animals.Conclusion: Long-term exercise training increased VEGF-A expression, leading to enhanced tumor vascularization and reduced tumor burden, multiplicity and histological aggressiveness.

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“…The emissivity of the object used (fresh pork meat and liver bought from a supermarket) is set to be 0.97. The human skin exhibits an emissivity 0.97, 17 and is very close with the emissivity values of the pork meat 18 and liver. 19 The distance parameter is required to compensate for the fact that radiation could be absorbed and lost during its transmission into camera lens.…”

Section: Parameters Setting For Infrared Cameramentioning

confidence: 61%

Thermal infrared images to quantify thermal ablation effects of acid and base on target tissues

2015

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Hyperthermia (42-46°C), treatment of tumor tissue through elevated temperature, offers several advantages including high cost-effectiveness, highly targeted ablation and fewer side effects and hence higher safety level over traditional therapies such as chemotherapy and radiotherapy. Recently, hyperthermia using heat release through exothermic acid-base neutralization comes into view owing to its relatively safe products of salt and water and highly confined ablation. However, lack of quantitative understanding of the spatial and temporal temperature profiles that are produced by simultaneous diffusion of liquid chemical and its chemical reaction within tumor tissue impedes the application of this method. This article is dedicated to quantify thermal ablation effects of acid and base both individually and as in neutralization via infrared captured thermal images. A theoretical model is used to approximate specific heat absorption rate (SAR) based on experimental measurements that contrast two types of tissue, normal pork and pig liver. According to the computation, both pork and liver tissue has a higher ability in absorbing hydrochloric acid (HCl) than sodium hydroxide, hence suggesting that a reduced dosage for HCl is appropriate in a surgery. The heating effect depends heavily on the properties of tissue types and amount of chemical reagents administered. Given thermal parameters such as SAR for different tissues, a computational model can be made in predicting temperature transitions which will be helpful in planning and optimizing surgical hyperthermia procedures.

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Determining the emissivity of pig skin for accurate infrared thermography

Cited by 84 publications

References 25 publications

Experimental measurement of microwave ablation heating pattern and comparison to computer simulations

Experimental measurement of microwave ablation heating pattern and comparison to computer simulations

Long-term exercise training as a modulator of mammary cancer vascularization

Thermal infrared images to quantify thermal ablation effects of acid and base on target tissues

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