What is it about?
Postpartum hemorrhage (PPH) is a leading but largely preventable cause of maternal deaths worldwide. This study compares two non-invasive optical technologies — Speckle Plethysmography (SPG) and Photoplethysmography (PPG) — for monitoring blood flow across different skin tones. SPG uses laser speckle patterns to measure blood flow, while PPG uses light absorption to detect pulse. In preliminary tests, SPG maintained signal quality even under low blood perfusion conditions where PPG signals degraded, and ongoing work evaluates both technologies across the full Fitzpatrick skin tone scale.
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Photo by Mohammad Hossein Farahzadi on Unsplash
Why is it important?
PPH accounts for 8% of maternal deaths in developed regions and nearly 20% in developing regions, making it a critical global health challenge. Current monitoring relies on late-appearing clinical symptoms and imprecise blood loss estimates. This research advances a more robust, AI-integrated technology (SPG) that works reliably across diverse skin tones — addressing a known equity gap in medical devices that have historically underperformed for patients with darker skin. If validated, SPG could enable earlier, more accurate detection of PPH risk, potentially saving thousands of lives annually.
Perspectives
Participating in this article was a truly rewarding experience, and it was a genuine pleasure collaborating with such a dedicated team of co-authors. Beyond the science itself, this work carries a deeper meaning for me — we are actively contributing to a more inclusive approach to clinical validation and medical technology development. I am proud that we are part of a growing movement to ensure that the solutions we build do not discriminate, work equitably across diverse populations, and can truly be used by anyone, regardless of their skin tone or background. Equity in healthcare technology is not just a goal — it is a responsibility, and I look forward to continuing to push that mission forward.
Hector Torres
University of Massachusetts Lowell
Read the Original
This page is a summary of: Comparative study of speckle plethysmography and photoplethysmography in diverse skin tones to further postpartum hemorrhaging monitoring technology, March 2026, SPIE,
DOI: 10.1117/12.3081284.
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