Photo of Rolf Saager

Rolf Saager

Associate Professor

My primary focus is to develop methods and instrumentation that advance spectroscopy, light transport modeling, and imaging of tissue; creating non-invasive tools for the clinical detection, monitoring or treatment of skin diseases and injuries.

Quantitative Biomedical Imaging and Spectroscopy in Dermatology and Wound Healing

Spatial Frequency Domain Imaging/spectroscopy (SFDI/S) is a relatively new technique that has several appealing attributes as a general measurement platform: low cost, quantitative in optical contrast, depth selective and spatially scalable. This technique measures the differentiated response of remitted light from tissue, when patterns (sinusoidal intensity projections of varying spatial frequency) are projected on to it. This approach quantifies the effective Modulation Transfer Function (MTF) of a diffuse optical system (in this case: tissue) and relates this function in terms of contributions from absorption and scattering.

Technology Development and Evaluation

Our lab advances spectroscopic methods in a way that exploits the molecular sensitivity, quantitation and non-invasiveness of SFDI/S, but extends the spatial resolution and depth selectivity through the use of recent advances in imaging technology (e.g. snap-shot hyperspectral imagers) and compressive sensing (e.g. single pixel imagers), as well as novel computational methods and models of light transport in order to translate these technologies into clinical settings.  

Clinical Applications and Deployment

The primary thrust of our research is focused on applications and collaborations that seek to address unmet needs in either primarily dermatological or models of disease in pre-clinical (small animal) settings: 

  • In terms of diagnostics, this measurement platform presents the opportunity to isolate (in space and depth) physiological and functional properties that directly relates to the biological processes present in disease or cancer.  We seek to develop non-invasive imaging tools with increased sensitivity and specificity to biological processes, thereby developing new, quantitative platform to study disease rather than just differentiating it. 
  • In terms of advancing light based therapies, this platform has the opportunity to characterize the optical properties present within affected tissue and therefore inform energy distribution of the light dose, as well as the therapeutic response. Light based treatment methods provide an exciting alternative to current cancer treatment methods as they could be (1) highly targeted, resulting in minimal collateral damage to healthy tissue, as well as (2) non- (or minimally) invasive, mitigating risks associated with surgical procedures. These methods, however, have yet to gain clinical acceptance due to a lack of quantitative imaging and evaluation tools. Two classes of therapies of particular interest are Photothermal Therapy (PTT) and Photodynamic Therapy (PDT).
  • Lastly, this platform has the opportunity to monitor structural changes in tissue in response to therapy and wound healing. Preliminary data indicate that all phases of the wound healing response (i.e. Hemostasis, Inflammation, Proliferation/ Granulation, and Tissue Remodeling/Maturation) and can be non-invasively identified and monitored longitudinally by the quantitative optical methods and models available in our lab. This platform not only allows for predictive therapeutic response, but also invites collaborations to study interventions that may promote and/or accelerate wound healing; thereby help expedite drug development in regenerative medicine. 



Hady Shahin, Luigi Belcastro, Jyotirmoy Das, Marina Perdiki Grigoriadi, Rolf Saager, Ingrid Steinvall, Folke Sjöberg, Pia Olofsson, Moustafa Elmasry, Ahmed Elserafy (2024) MicroRNA-155 mediates multiple gene regulations pertinent to the role of human adipose-derived mesenchymal stem cells in skin regeneration Frontiers in Bioengineering and Biotechnology, Vol. 12, Article 1328504 Continue to DOI


Hanna Jonsson, Joakim Henricson, Rolf Saager, Daniel Wilhelms (2023) Microcirculatory response to lower body negative pressure and the association to large vessel function PHOTONICS IN DERMATOLOGY AND PLASTIC SURGERY 2023, Article 123520A Continue to DOI
Johannes Johansson, Rolf Saager (2023) Development of a novel line scanner for speckle contrast diffuse correlation tomography of microvascular blood flow OPTICAL DIAGNOSTICS AND SENSING XXIII, Article 123870A Continue to DOI
Luigi Belcastro, Hanna Jonasson, Tomas Strömberg, Ahmed Elserafy, Rolf Saager (2023) Beneath the skin: multi-frequency SFDI to detect thin layers of skin using light scattering PHOTONICS IN DERMATOLOGY AND PLASTIC SURGERY 2023, Article 1235209 Continue to DOI


Motasam Majedy, Nandan K. Das, Johannes Johansson, Rolf B. Saager (2022) Influence of optical aberrations on depth-specific spatial frequency domain techniques Journal of Biomedical Optics, Vol. 27 Continue to DOI

Research Group