Project function: PhD candidate
Organisation: Technische Universiteit Delft
Newsletter (2) November 2012
In the STW annual congress 2012 “Tech Talks” Yusang Wu won Simon Stevin Leerlingprijs, a prize for the best poster presented in the congress and with 1000 euros as a reward. In a two-minute pitch talk Wu convinced the most audience the applicability of the research of Project Beyond Pain into the development of a technique for the early diagnosis of SFN.
The main challenge in the Beyond Pain project is the application of system identification techniques for the assessment of small fiber function. Skin thermoregulation is a complicated process and not fully understood yet. Skin blood flow is one of the major approaches of skin thermoregulation. The control of skin blood flow is maintained by the central nervous system and locally by A-delta and C fibers (i.e. small nerve fiber). The Beyond Pain project is progressing with following tasks:
• A thermal perturbation device using a medical infrared lamp is in design. This new device is used to provoke a local vasomotor response of skin in healthy subjects and eventually patients.
• Skin temperature is measured with a thermographic video-camera. The video thermography is further processed in order to obtain a comprehensive characterization of the skin temperature response. Custom-made software (written in Matlab) using parallel-computing was developed for processing the videothermography.
• Standard skin biopsy labeling (PGP9.5) and nerve fiber counting was developed at Erasmus MC and is available for application.
• The experiment in a healthy control group is ongoing in Erasmus MC, Rotterdam. A first patient study with CHDR in Leiden is finished and the data is being analyzed at this moment. There are multiple clinical purposes: 1) Investigation of the applicability of our setup and method; 2) Quantification of the effect of age and gender on skin thermoregulation; 3) Analysis of the change of skin vasomotor response in a double blind experiment.
For questions about the clinical part and the skin biopsy of Beyond Pain project contact Mariska. D. Nieuwenhoff (Erasmus MC). For general questions on the device contact Yusang Wu (TU Delft).
Newsletter (1) April 2012
Small fiber neuropathy (SFN) is a sensory neuropathy that affects small fibers and their functions. There is not a gold standard for the diagnosis of SFN, while skin biopsy with an assessment of intra-epidermal nerve fiber density is considered as an effective assisting method. Skin biopsy, however, is invasive, labor-intensive and has limited accuracy. The goal of Beyond Pain is to develop a technique that enables quantitative and non-invasive diagnosis of SFN.
SFN is known to affect the local vasomotor response of skin. With our technique method the subjects’ skin is locally heated up to maximally 42 ℃ with an infrared lamp (Hydrosun). The thermal response of the skin is evaluated based on two signals: 1) local skin blood flow, measured with laser Doppler flowmetry and 2) local skin temperature, measured with a thermography camera (FLIR SC5600). The first results on healthy volunteers demonstrate that the regulation of skin temperature can be assessed with our technique. In the cooling phase the skin blood flow stabilizes in 120 seconds, while the skin temperature keeps decreasing. Tau imaging of the hand clearly visualizes the regions with different thermal properties. In 2013 we will test the methodology to investigate the effect of small fiber neuropathy on the thermoregulation of human skin.
Project Beyond pain: assessment and diagnosis of small fiber neuropathy through identification of vasomotion (dys)function
About 2% of the world population suffers from small nerve fiber dysfunction, which can result in neuropathic pain; diabetic patients represent one of the main subgroups of this population. Small fiber dysfunction is known to modulate local blood flow (vasomotion) in response to painful (nociceptive) and non-painful (non-nociceptive) temperature stimuli to the skin. Within the project a measurement system and thermoregulatory model will be developed to provide a non-invasive objective and instantaneous assessment of small fiber dysfunction. Thermoregulatory control will be assessed in both healthy controls and patients with a painful neuropathy, using closed-loop system identification techniques.
2 PhDs will perform their research in a multi-disciplinary team based at the Department of Biomechanical Engineering, Faculty of 3mE , Delft University of Technology (DUT), and at the Erasmus Medical Center. The candidate at Erasmuc MC should have a background in (Technical) Medicine or Life Science and have affinity with Biomedical Engineering; the candidate at DUT in (Bio)Mechanical, Electrical Engineering or (Applied) Physics. Both positions have been fulfilled.
Flir (Infrared technologies), Noldus (Information Technology) , CHDR (Centre for Human Drug Research)