Plethysmography Research

Kim SW, Kim SC, Nam KC, Kang ES, Im JJ, Kim DW. A new method of screening for diabetic neuropathy using laser Doppler and photoplethysmography. Med Bio Eng Comput 2008; 46: 61-67. 

  • Our suggested PPG method using the toe to finger ratio is reliable, simple, economical, and accurate, and could become an effective new screening tool for the early detection of diabetic neuropathy. 
  • One of the most important findings in this study is that the blood volume change ratio of toe to finger may distinguish neuropathic diabetes from non-neuropathic diabetes with a high sensitivity and specificity.

Kim DW, Ryu CR, Kim SC, Nam KC. A new diagnostic method for detecting neuropathic diabetic foot by photoplethysmography. Proceedings of the 25th Annual International Conference of the IEEE EMBS 2003; 3130-3132. 

  • Therefore, the blood flow ratio of the toes to the fingers is suggested as a new diagnostic parameter in diabetic neuropathy by simple photo-plethysmography.

Kim DW, Kim SW, Kim SC, Nam KC, Kang ES, Im JJ. Detection of diabetic neuropathy using blood volume ratio of finger and toe by PPG. Proceedings of the 29th Annual International Conference of the IEEE EMBS 2007; 2211-2214.

  • Sensitivities of the PPG method were found to be 98.0 % for both sides. Specificities were found to be 98.4 % for the left and 92.2% for the right side. The suggested PPG method is
    reliable, simple, low-cost, and noninvasive which could become an effective new screening tool for the early detection of diabetic neuropathic foot.

Allen J. Photoplethysmography and its application in clinical physiological measurement 2007; Physiol Meas 28: R1-R39.

  • There has been a resurgence of interest in the technique in recent years, driven by the demand for low cost, simple and portable technology for the primary care and community based clinical settings, the wide availability of low cost and small semiconductor components, and the advancement of computer-based pulse wave analysis techniques.
  • The PPG technology has been used in a wide range of commercially available medical devices for measuring oxygen saturation, blood pressure and cardiac output, assessing autonomic function and also detecting peripheral vascular disease.
  • A variety of pulse wave analysis techniques have been used, including power spectral and correlation analysis, to characterize the beat-to-beat PPG amplitude variations attributed to sympathetic activity, as well as the left body side similarity in low frequency characteristics.
  • Further evidence that these fluctuations are linked to the been demonstrated by the increase in PTT following epidural anaesthesia treatment and the reduction in low frequency variability following thoracic sympathectomy. 
  • The degree of bilateral dissimilarity in the PPG low frequency characteristics for diabetic patients with neuropathy has also been measured.