Office of Technology Transfer – University of Michigan

Subsurface Raman Mapping with a Fiber Optic Array

Technology #3152

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Michael D. Morris
Managed By
Janani Ramaswamy
Licensing Specialist, Medical Deviceses 734-763-9081

Monitoring Wound Healing Complications

Accurate and timely evaluation of wound healing is critical for the prevention of long-term complications as well as the determination of the most effective treatment strategies for patients. Physicians are not always able to determine whether a wound is healing by visual inspection and there is a need for techniques that provide real-time information to surgeons as they make decisions in the operating room about what tissue to save and what tissue to remove. Tracking wound healing by traditional methods, which includes measuring the length, width, and depth of a wound, is highly variable and dependent on where the measurements are made and the individual conducting the measurements. Incorrect and delayed assessment of wound healing is particularly problematic for diabetic patients, which often undergo amputation as a result of foot ulcers that are not able to heal. Raman and infrared spectroscopic measurements are promising techniques that could provide early, rapid, and reliable information to assess wound healing and aid physicians in successfully treating patients.

Method and Apparatus for Evaluating Wound Healing Complications

In the proposed technology the composition of tissues affected by wound healing are assessed by acquired spectral signatures that can be related to alterations in the secondary structures of protein. The tissue is irradiated transcutaneously in the patient with a near-infrared Raman microprobe. The near-infrared excitation laser is line-focused through an Olympus microscope and Raman-scattered light is collected through the objective, dispersed, and integrated on a camera that is sensitive in the near-infrared. Several Raman spectra can be obtained at different sampling locations along the tissue and background signals and noise are minimized through normalization. The acquired Raman spectra bands are fit to a Gaussian/Lorentzian distribution and the band areas, which can provide information on changes in tissue composition including carbonate-to-phosphate ratios and the mineral-to-matrix ratio, are calculated. Disorders in the secondary structure of collagen can also be assessed based on Raman spectra band components. The technology has successfully detected abnormal acidic calcium phosphate minerals in patients with bone bacterial infections as a result of osteomyelitis, a common complication of foot wounds in diabetic patients. These compositional measurements can provide insight into the pathology of bacterial bone infections and diabetic wound healing, as well as serve as an early stage diagnostic tool.


  • Tissue Evaluation
  • Examine wound healing
  • Determine tissue constituents
  • Monitor infection
  • Assess tissue growth
  • Observe tissue deterioration


  • Portable
  • Non-destructive
  • High sensitivity
  • Real-time analysis
  • In-vivo evaluation
  • Minimally invasive
  • Easily combined with imaging