Elfi-Tech can measure pain objectively

Pain is one of the most common reasons for consulting with physicians (1,2). It is the major presenting symptom in many medical conditions, and can interfere with a person’s quality of life and general functioning (3). The total costs of prescription medications prescribed for pain were $17.8 billion annually in the United States (4). Simple pain medications are useful in 20% to 70% of cases (5). Patients who do not respond to usual analgesic medications are treated with opiate medications. Opioids are a class of drugs that act in the nervous system to produce feelings of pleasure and pain relief. Some opioids are legally prescribed by healthcare providers to manage severe and chronic pain. Commonly prescribed opioids include oxycodone, fentanyl, buprenorphine, methadone, oxymorphone, hydrocodone, codeine, and morphine (6). Unfortunately, many prescription opioids are overprescribed, misused or diverted to others, leading to the current addiction crisis in the United States and Europe (7).

Pain is a subjective symptom, and the perception of pain is dependent on individual differences in physiological, emotional and cognitive states (8). Currently there is no easily available methodology to objectively quantitate an individual’s pain, and it is therefore difficult for a physician to determine an individual’s pain level. Recent research efforts are exploring methods of objectively assessing pain, such as using functional MRI scanning (8), but these approaches are cumbersome, not validated, and not useful in the clinical setting.

Elfi-Tech LTD has developed a novel approach to measure acute and chronic pain in an objective and clinically useful manner. It is known that pain activates the autonomic nervous system, which in turn affects the hemodynamics of the peripheral blood circulation (9). Pain sensation, by acting through the autonomic nervous system, affects the blood flow in the microcirculation. Our sensing platform is based on a small optical sensor that emits coherent light into the skin and collects the reflected light from the red blood cells in the blood vessels in the skin under the sensor.  In preliminary studies we have performed with this sensor, we measured the dynamic light scattering signal from red blood cells flowing in skin, and noted significant changes in response to acute stress and acute pain (10).

The ability to objectively assess pain level in the clinic would be a boon for health care personnel caring for patients and would foster responsible prescribing practices prevent overuse of opioids and help curb the current opioid epidemic.



  1. Debono DJ, Hoeksema LJ, Hobbs RD (August 2013). “Caring for patients with chronic pain: pearls and pitfalls“. The Journal of the American Osteopathic Association. 113 (8): 620–7. doi:10.7556/jaoa.2013.023. PMID 23918913.
  2. Turk DC, Dworkin RH (2004). “What should be the core outcomes in chronic pain clinical trials?“. Arthritis Research & Therapy. 6 (4): 151–4. doi:10.1186/ar1196. PMC 464897. PMID 15225358.
  3. Breivik H, Borchgrevink PC, Allen SM, Rosseland LA, Romundstad L, Hals EK, Kvarstein G, Stubhaug A (July 2008). “Assessment of pain“. British Journal of Anaesthesia. 101 (1): 17–24. doi:10.1093/bja/aen103. PMID 18487245.
  4. Rasu RS1, Vouthy K, Crowl AN, Stegeman AE, Fikru B, Bawa WA, Knell ME. “Cost of pain medication to treat adult patients with nonmalignant chronic pain in the United States”. J Manag Care Spec Pharm. 2014 Sep;20(9):921-8.
  1. Moore RA, Wiffen PJ, Derry S, Maguire T, Roy YM, Tyrrell L (November 2015). “Non-prescription (OTC) oral analgesics for acute pain – an overview of Cochrane reviews“. The Cochrane Database of Systematic Reviews. 11 (11): CD010794. doi:10.1002/14651858.CD010794.pub2. PMC 6485506. PMID 26544675.
  2. https://ghr.nlm.nih.gov/condition/opioid-addiction
  3. https://www.statnews.com/2019/06/21/surgeons-overprescribed-opioids-analysis-shows/
  4. E. Wilcox, A. R. Mayer, T. M. Teshiba, J. Ling, B. W. Smith, G. L. Wilcox, and P.l G. Mullins. “The Subjective Experience of Pain: an FMRI Study of Percept-related Models and Functional Connectivity”. Pain Med. 2015 Nov; 16(11): 2121–2133.
  5. Bernardil, L., Hayoz, D. Wenzel, R., Passino, C., Calciati, A., Weber, R., and Noll, G., “Synchronous and baroceptor-sensitive oscillations in skin microcirculation: evidence for central autonomic control”, Am J Physiol. Oct ;273(4 Pt 2):H1867-78 (1997).
  6. Adi Schejter Bar-Noam, A. Kaminsky, A. Bravo, L. Shenkman, Nacasch, I. Fine, “Novel method for non-invasive blood pressure measurement from the finger using an optical system based on dynamic light scattering,” Proc. SPIE 11075, Novel Biophotonics Techniques and Applications V, 110750P (22 July 2019); doi: 10.1117/12.2525685