Prediction of wound healing in human diabetic foot ulcers by diffuse near-infrared spectroscopy: A pilot study

Abstract

A human study was conducted in which the efficacy of in vivo diffuse near-infrared (NIR) spectroscopy was demonstrated in predicting wound healing in diabetic foot ulcers. Sixteen chronic diabetic wounds were followed and assessed for subsurface oxy-hemoglobin concentration using the NIR device. Weekly measurements were conducted until there was wound closure, limb amputation, or 20 completed visits without healing. Digital photography measured wound size, and the degree of wound contraction was compared with the NIR results. In the 16 patients followed, seven wounds healed, six limbs were amputated, and three wounds remained opened after 20 visits. The initial values in subsurface hemoglobin concentration in all wounds were higher than the nonwound control sites. Healed wounds showed a consistent reduction of hemoglobin concentration several weeks before closure that approached control site values. In wounds that did not heal or resulted in amputation of the limb, the hemoglobin concentration remained elevated. In some cases, these nonhealing wounds appeared to be improving clinically. A negative slope for the rate of change of hemoglobin concentration was indicative of healing across all wounds. In conclusion, evaluation of wounds using NIR may provide an effective measurement of wound healing. NIR spectroscopy can determine wound healing earlier than that visibly assessed by current clinical approaches.

Diabetic Wound Imaging Using a Noncontact Near-Infrared Scanner

“…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.…”

Critical Review of Noninvasive Optical Technologies for Wound Imaging

“…Moreover, the evaluation of wounds can also be based on observations such as wound size, color, odor, and level of pain. 3,6,8,9 These methods have their limitations in terms of effectiveness due to invasiveness and disruption because they introduce a new wound that interferes with the assessment of the wound healing process. This prevents the precise assessment of wound to heal over time and the evaluation of recurrent wounds where patients have high risk of infection.…”

“…NIRS is able to differentiate between oxygenated and deoxygenated blood, which confers a distinct theoretical advantage to this modality. 3,5,9,[18][19][20][21][22][23][24] A general schematic of an NIRS system is shown in Fig. 2.…”

“…If the wound does not heal beyond 4 weeks, reevaluation of wound and other treatment options are considered. [1][2][3] The gold-standard clinical wound monitoring approach during its treatment process is by visual inspection of changes in the wound site, along with physical measurements of the wound size and depth. The underlying changes in the blood oxygenation or wound microstructure can differ with the wound's healing or nonhealing nature.…”

“…NIRS has shown to provide information about blood perfusion (based on oxygenation), 26 monitor chronic wound in rats, [22][23][24] and monitor wound healing by differentiating healing from nonhealing DFUs in human subjects. 3,18 Diffuse reflectance spectroscopy DRS is an optical imaging technique that relies on the focused projection of the spectrometer beam (of wavelengths varying across visible, infrared, etc.) into the sample where it is reflected, scattered, and then transmitted through the sample material.…”