590828
research-article2015
DSTXXX10.1177/1932296815590828Journal of Diabetes Science and TechnologyGodavarty et al
Letter to the Editor
Diabetic Wound Imaging Using a Noncontact Near-Infrared Scanner: A Pilot Study
Journal of Diabetes Science and Technology 1–2 © 2015 Diabetes Technology Society Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1932296815590828 dst.sagepub.com
Anuradha Godavarty, PhD1, P. N. Someshwara Rao, DPM2, Yamini Khandavilli, B.Tech3, and Young-Jin Jung, PhD4 Keywords diabetic foot ulcers, diffuse optical imaging, hand-held, near-infrared, optical scanner
An estimated 15% of all patients suffering with diabetes will develop foot ulcers.1 To date, clinicians employ visual inspection of the wound site during its standard 4-week healing process via monitoring of surface granulation. However, surface granulation is not an implication of internal healing in many cases. If left untreated immediately, the extent of leg/foot amputation may increase due to lack of response to the treatment. Near-infrared spectroscopy (NIRS) is an emerging noninvasive and nonionizing technology that can map the changes in hemodynamics in the site of interest (eg, the wounded and healthy tissue site) even up to a few centimeters deep. Researchers have implemented NIRS toward wound healing studies in animals and pilot human subject studies as well.2-3 Herein, a near-infrared optical scanner (NIROS) is implemented in differentiating healing/nonhealing foot ulcers. NIROS was set up to image large tissue surfaces (>12 cm2) without contact using an LED-based source and an NIR sensitive camera (IDS, Germany). A custom-developed imaging software is used to acquire diffuse reflected NIR images in real time from the tissue surface. IRB-approved imaging studies were carried out on 4 diabetic subjects with wounds at Somesh’s Diabetic Foot Clinic, Chennai, India (www.ndiabeticfoot.com). Diffuse reflected optical images were acquired from the wound and its surrounding regions in all subjects. The optical contrast of wound:peripheries was estimated from the intensity distribution in the wound with respect to its peripheries. From the qualitative and quantitative analysis, it was observed that there is a negative wound:background optical contrast in nonhealing wounds (see Figures 1a and 1c)
compared to a positive wound:background contrast in healing wounds (see Figures 1b and 1d). Healing wounds initially have a higher hemoglobin concentration in the wound site, and with time (in weeks) they tend to decrease and become closer to the hemoglobin concentrations of the normal background.2-3 On the contrary, nonhealing wounds have a higher hemoglobin concentration that does not decrease with time due to the chronic inflammatory phase of these wounds. Extent of absorption of NIR light is directly proportional to hemoglobin concentration. Hence, a negative optical contrast potentially indicates a greater hemoglobin concentration in the wound site with respect to the surroundings than a healing wound that progressed to cell proliferation stage (where hemoglobin is consumed). Thus, a biometric of positive and negative optical contrast is shown to differentiate healing and nonhealing wounds, with future emphasis on extensive studies to validate the results.
1
Optical Imaging Laboratory, Department of Biomedical Engineering, Florida International University, Miami, FL, USA 2 Somesh Diabetic Foot Clinic, Chennai, India 3 Department of Computer Science, SRM University, Chennai, India 4 Center for Advanced Rehabilitation/Research and Education, College of Nursing and Health Science, Florida International University, Miami, FL, USA Corresponding Author: Anuradha Godavarty, PhD, Department of Biomedical Engineering, Florida International University, EC 2675, 10555 W Flagler St, Miami, FL 33174, USA. Email: [email protected]
Downloaded from dst.sagepub.com at NORTH DAKOTA STATE UNIV LIB on July 16, 2015
2
Journal of Diabetes Science and Technology
Figure 1. Near-infrared optical images of diabetic subjects with healing or nonhealing ulcers. The plots in third column correspond to the zoomed out region of interest with the intensity profile at a chosen y-plane. The intensity varies from max to min along the y-axis. All cases employed 710 nm LED light source. Healing wounds show a positive optical contrast, while nonhealing wounds show a negative optical contrast.
Abbreviations
Funding
LED, light-emitting diode; NIR, near-infrared; NIROS, near-infrared optical scanner; NIRS, near-infrared spectroscopy.
NIH (R15CA119253) and Florida International University, Division of Research’s Seed Funds provided funding.
References
Acknowledgments The first author would like to thank NIH and Florida International University, Division of Research’s Seed Funds for funding.
Declaration of Conflicting Interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
1. Ostomy Wound Management. Diabetic foot care: the state of play in India. Available at: http://www.o-wm.com/content/ diabetic-foot-care-the-state-play-india. 2. Neidrauer M, Zubkov L, Weingarten MS, Pourrezaei K, Papazoglou ES. Near infrared wound monitor helps clinical assessment of diabetic foot ulcers. J Diabetes Sci Technol. 2010;4(4):792-798. 3. Weingarten MS, Neidrauer M, Mateo A, et al. Prediction of wound healing in human diabetic foot ulcers by diffuse near-infrared spectroscopy: a pilot study. Wound Rep Reg. 2010;18:180-185.
Downloaded from dst.sagepub.com at NORTH DAKOTA STATE UNIV LIB on July 16, 2015
research-article2015
DSTXXX10.1177/1932296815590828Journal of Diabetes Science and TechnologyGodavarty et al
Letter to the Editor
Diabetic Wound Imaging Using a Noncontact Near-Infrared Scanner: A Pilot Study
Journal of Diabetes Science and Technology 1–2 © 2015 Diabetes Technology Society Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1932296815590828 dst.sagepub.com
Anuradha Godavarty, PhD1, P. N. Someshwara Rao, DPM2, Yamini Khandavilli, B.Tech3, and Young-Jin Jung, PhD4 Keywords diabetic foot ulcers, diffuse optical imaging, hand-held, near-infrared, optical scanner
An estimated 15% of all patients suffering with diabetes will develop foot ulcers.1 To date, clinicians employ visual inspection of the wound site during its standard 4-week healing process via monitoring of surface granulation. However, surface granulation is not an implication of internal healing in many cases. If left untreated immediately, the extent of leg/foot amputation may increase due to lack of response to the treatment. Near-infrared spectroscopy (NIRS) is an emerging noninvasive and nonionizing technology that can map the changes in hemodynamics in the site of interest (eg, the wounded and healthy tissue site) even up to a few centimeters deep. Researchers have implemented NIRS toward wound healing studies in animals and pilot human subject studies as well.2-3 Herein, a near-infrared optical scanner (NIROS) is implemented in differentiating healing/nonhealing foot ulcers. NIROS was set up to image large tissue surfaces (>12 cm2) without contact using an LED-based source and an NIR sensitive camera (IDS, Germany). A custom-developed imaging software is used to acquire diffuse reflected NIR images in real time from the tissue surface. IRB-approved imaging studies were carried out on 4 diabetic subjects with wounds at Somesh’s Diabetic Foot Clinic, Chennai, India (www.ndiabeticfoot.com). Diffuse reflected optical images were acquired from the wound and its surrounding regions in all subjects. The optical contrast of wound:peripheries was estimated from the intensity distribution in the wound with respect to its peripheries. From the qualitative and quantitative analysis, it was observed that there is a negative wound:background optical contrast in nonhealing wounds (see Figures 1a and 1c)
compared to a positive wound:background contrast in healing wounds (see Figures 1b and 1d). Healing wounds initially have a higher hemoglobin concentration in the wound site, and with time (in weeks) they tend to decrease and become closer to the hemoglobin concentrations of the normal background.2-3 On the contrary, nonhealing wounds have a higher hemoglobin concentration that does not decrease with time due to the chronic inflammatory phase of these wounds. Extent of absorption of NIR light is directly proportional to hemoglobin concentration. Hence, a negative optical contrast potentially indicates a greater hemoglobin concentration in the wound site with respect to the surroundings than a healing wound that progressed to cell proliferation stage (where hemoglobin is consumed). Thus, a biometric of positive and negative optical contrast is shown to differentiate healing and nonhealing wounds, with future emphasis on extensive studies to validate the results.
1
Optical Imaging Laboratory, Department of Biomedical Engineering, Florida International University, Miami, FL, USA 2 Somesh Diabetic Foot Clinic, Chennai, India 3 Department of Computer Science, SRM University, Chennai, India 4 Center for Advanced Rehabilitation/Research and Education, College of Nursing and Health Science, Florida International University, Miami, FL, USA Corresponding Author: Anuradha Godavarty, PhD, Department of Biomedical Engineering, Florida International University, EC 2675, 10555 W Flagler St, Miami, FL 33174, USA. Email: [email protected]
Downloaded from dst.sagepub.com at NORTH DAKOTA STATE UNIV LIB on July 16, 2015
2
Journal of Diabetes Science and Technology
Figure 1. Near-infrared optical images of diabetic subjects with healing or nonhealing ulcers. The plots in third column correspond to the zoomed out region of interest with the intensity profile at a chosen y-plane. The intensity varies from max to min along the y-axis. All cases employed 710 nm LED light source. Healing wounds show a positive optical contrast, while nonhealing wounds show a negative optical contrast.
Abbreviations
Funding
LED, light-emitting diode; NIR, near-infrared; NIROS, near-infrared optical scanner; NIRS, near-infrared spectroscopy.
NIH (R15CA119253) and Florida International University, Division of Research’s Seed Funds provided funding.
References
Acknowledgments The first author would like to thank NIH and Florida International University, Division of Research’s Seed Funds for funding.
Declaration of Conflicting Interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
1. Ostomy Wound Management. Diabetic foot care: the state of play in India. Available at: http://www.o-wm.com/content/ diabetic-foot-care-the-state-play-india. 2. Neidrauer M, Zubkov L, Weingarten MS, Pourrezaei K, Papazoglou ES. Near infrared wound monitor helps clinical assessment of diabetic foot ulcers. J Diabetes Sci Technol. 2010;4(4):792-798. 3. Weingarten MS, Neidrauer M, Mateo A, et al. Prediction of wound healing in human diabetic foot ulcers by diffuse near-infrared spectroscopy: a pilot study. Wound Rep Reg. 2010;18:180-185.
Downloaded from dst.sagepub.com at NORTH DAKOTA STATE UNIV LIB on July 16, 2015
