Complications of the diabetic foot proliferate from ischemic and/or neuropathic conditions in the form of excess tissue build-up or callus. Plantar calluses are thick and soft and form as a result of neuropathy at the toe apices and metatarsals head and/or toe tips. Neuro-ischemic calluses appear thin, hard, dry and/or glassy and typically form at the borders of the feet and/or on main weight bearing areas. It is standard practice for the clinician to remove this excess tissue to reduce pressure in the diabetic foot which reduces the risk of ulceration. The dead tissue layers are removed in a surgical process known as scalpel debridement, or chiropody. It is not uncommon for a clinician to encounter a buried wound in the process of scalpel debridement. However, the process itself is not straightforward in that the extent of debridement is not measurable between clinicians. The debridement process removes tissue up to the epidermal-dermal junction, which may be difficult to identify for an inexperienced clinician. In an effort to measure the effect of scalpel debridement, near infrared (NIR) imaging was applied in an IRB study between Florida International University and Dr. Mohan’s Diabetes Specialties Centre in Chennai, India. Subjects were assessed before and after the debridement procedure. NIR images at multiple wavelengths were obtained before and after debridement to estimate changes in tissue oxygenation in the callus and surrounding peri-callus regions. A method to analyze the significance of oxygenation change occurring both overall and within sub-quadrants of the callus is conducted to assess the effect of debridement. Measuring changes in tissue oxygenation may potentially be used in future clinical applications to improve the debridement process and reduce the risk of ulceration.
According to the American Cancer Society, it is projected that 1.8 million new cancer cases will arise. Of these new cases, 15% are expected to be Breast Cancer related. For many subjects undergoing radiation therapy (RT), radiation dermatitis (RD) is an unavoidable adverse reaction to necessary treatment. As much as 95% of RT subjects will experience RD during or after their treatment plan which can range from mild erythema to full necrosis of the treated tissue. Further complicating matters, the standard assessment approach for RD, the Common Terminology Criteria for Adverse Events (CTCAE), is subjective and relies on the treating clinician’s visual assessment. Assessment of oxygenated blood flow changes holds potential as a means of assessing the severity of RD. In this study, spatial-temporal changes of tissue oxygenation, via a breath-hold paradigm, were monitored in breast cancer subjects across weeks of RT using a near infrared imaging approach. Subjects were imaged dynamically to acquire 2D spatial-temporal maps of tissue oxygenation. A Pearson’s correlation-based approach was applied to spatial-temporal oxygenation maps to determine the extent of symmetry or asymmetry in oxygenated blood flow patterns. Current results indicate that the oxygenated blood flow in tissue regions neighboring the irradiated site are affected by radiation dermatitis. These results are significant as they infer that RT induces altered oxygenated blood flow that could potentially be correlated to RD severity, apart from static tissue oxygenation measurements.
Major challenges in diabetic foot ulcer (DFU) treatment include compliance and routine clinical visits to facilitate healing. Virtual Medicine (VM) can greatly impact DFU wound care management with tools for remote patient monitoring (RPM). Herein, a novel low-cost smartphone-based imaging device was developed to provide physiological (in terms of tissue oxygenation) and visual measurements of DFUs. Quantitative changes in tissue oxygenation between the wound and peri-wound in DFUs are obtained using SPOT device in an IRB approved pilot study. On a long-term, SPOT has potential to offer a low-cost alternative for VM and RPM in DFU wound care management.
KEYWORDS: Biomedical optics and medical imaging, Medical imaging, Tissues, Chest, Tissue optics, Breast cancer, Skin, Cancer, Oxygen, Radiotherapy, Skin cancer
The American Cancer Society has estimated that a total of 1.8 million new cancer cases will arise in 2020, 15% percent of which are breast cancer. Radiation therapy (RT) is widely used post mastectomy or lumpectomy as a method of avoiding recurrence of disease in affected regions. Photon and proton therapy are among the main forms of RT currently applied to breast cancer patients. The effectiveness of photon vs proton therapy has been studied in various cancer models from differences in subjective clinical grading of radiation dermatitis (RD), a common side effect of RT. Herein, an objective physiological imaging approach using near-infrared optical techniques is implemented to quantitatively differentiate the effectiveness of proton vs photon therapy in breast cancer subjects undergoing RT. A 6-8 week longitudinal pilot study (WIRB approved) was carried out on 10 breast cancer subjects undergoing RT at Miami Cancer Institute (MCI). The chest wall, axilla, and lower neck were imaged on the irradiated and the non-irradiated (contralateral) sides of the torso to measure for tissue oxygenation changes. From preliminary analysis, it was observed that were distinct differences in tissue oxygenation and RD in the irradiated regions when compared to their contralateral nonirradiated tissue (reference). Changes in tissue oxygenation and skin toxicity (i.e. RD clinical grading) were more localized and less severe in subjects receiving proton therapy compared to photon therapy. Quantitative comparison of oxygenation changes and its correlation to the skin toxicity levels in photon vs proton therapy treated breast cancer subjects is currently carried out.
Diabetic Foot Ulcers (DFUs) are responsible for 20% of diabetic-related hospitalization and 85% of diabetes related amputations. In DFUs the primary factor affecting healing is an adequate oxygen supply to the wound. However, the gold standard approach for assessing DFUs is by evaluating the reduction of wound size over a four-week period. In this study, we investigate the potential of altered breathing patterns as a technique to assess localized oxygenated perfusion in DFUs as a measure of healing potential. A continuous wave (CW), non-contact, near infrared optical scanner (NIROS) was used to conduct NIR based spectroscopic imaging at dual discrete wavelengths (729nm and 799nm) on DFUs with 7mW of maximum optical power. Subjects were imaged at discrete time points and dynamically utilizing an altered breathing paradigm (i.e. breath-hold) to measure the relative oxy- (ΔHbO) and deoxyhemoglobin (ΔHbR) changes in normal and DFU scenarios. Results show that in normal individuals, ΔHbO/ΔHbR changes at all points of the foot because of altered breathing patterns are synchronous; whereas in the DFU scenario changes in hemodynamic parameters are asynchronous. This indicates that under normal circumstances, oxygenated perfusion changes are consistent and uniform at all points of the foot as opposed to the DFU scenario’s inconsistent oxygenated perfusion. Altered breathing paradigms may serve as a useful tool in assessing localized sub-surface oxygenated perfusion in regions around the wound, and help clinicians better cater the treatment process.
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