Optical sensors for the in vivo assessment of flap perfusion in plastic surgery

摘要: Following mastectomy for breast cancer a wide variety of surgical techniques are currently available post reconstruction where autologous tissue is used to construct natural looking breast. One the most common types reconstructive surgeries use Deep Inferior Epigastric Perforator (DIEP) free flap skin and adipose along with their blood supplies transferred from lower abdomen chest. The success surgery depends strongly on maintenance adequate perfusion in flap. Early diagnosis ischaemia exploration restore flow can often salvage may prevent graft failure. Even though many have been used, there still need develop non-invasive, easy use, reproducible inexpensive monitoring device assess perfusion. In an attempt overcome limitations current prototype reflectance three wavelength photoplethysmographic (PPG) sensor was developed. PPG consisted two infrared (940 nm), green (520 nm) red (660 LEDs photodiode. A processing system also constructed order drive optical components detect pre-process signals. Virtual Instrument (VI) implemented LabVIEW display, analyse archive signals capability real-time estimation arterial oxygen saturation (SpO2) values. evaluated pilot study fifteen patients undergoing using flaps. Good quality red, were obtained pre-operatively donor site (abdomen), intra-operatively (capturing reperfusion following anastomosis) post-operatively at regular intervals up 12 hours surgery. SpO2 values estimated which found be broad agreement recorded commercial pulse oximeter attached patients’ finger. PPGs compared SpO2s acquired finger small number custom made probe, optically electrically, identical as probe. much larger than confirms hypothesis inadequate during after operative period. Furthermore successfully series case studies evaluate versatility estimating other These included Latissimus Dorsi (pedicle) head neck Vertical Rectus Abdominis Myocutaneous (VRAM) total petrosectomy. Also, oesophagus jejunum flaps recruited into study. For this purpose build oesophageal demonstrated ability developed sensors acquire estimate results confirmed that has potential alternative technique various all periods.