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Enhanced Photoacoustic Visualisation of Clinical Needles by Combining Interstitial and Extracorporeal Illumination of Elastomeric Nanocomposite Coatings

Research output: Contribution to journalArticlepeer-review

Mengjie Shi, Semyon Bodian, Simeon J. West, Sanjayan Sathasivam, Ross Gordon, Paul Collier, Tom Vercauteren, Adrien E. Desjardins, Sacha Noimark, Wenfeng Xia

Original languageEnglish
Article number6417
JournalSensors (Switzerland)
Issue number17
Published25 Aug 2022

Bibliographical note

Funding Information: This research was funded in whole, or in part, by the Wellcome Trust [203148/Z/16/Z, WT101957, 203145Z/16/Z], the Engineering and Physical Science Research Council (EPSRC) (NS/A000027/1, NS/A000050/1, NS/A000049/1), EPSRC UKRI Innovation Fellowship (EP/S001506/1), Johnson Matthey PLC (grant no. JM11372), and King’s—China Scholarship Council PhD Scholarship Program (K-CSC) (202008060071). For the purpose of open access, the author has applied a CC BY public copyright license to any author-accepted manuscript version arising from this submission. Publisher Copyright: © 2022 by the authors.


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    Uploaded date:31 Aug 2022

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King's Authors


Ultrasound (US) image guidance is widely used for minimally invasive procedures, but the invasive medical devices (such as metallic needles), especially their tips, can be poorly visualised in US images, leading to significant complications. Photoacoustic (PA) imaging is promising for visualising invasive devices and peripheral tissue targets. Light-emitting diodes (LEDs) acting as PA excitation sources facilitate the clinical translation of PA imaging, but the image quality is degraded due to the low pulse energy leading to insufficient contrast with needles at deep locations. In this paper, photoacoustic visualisation of clinical needles was enhanced by elastomeric nanocomposite coatings with superficial and interstitial illumination. Candle soot nanoparticle-polydimethylsiloxane (CSNP-PDMS) composites with high optical absorption and large thermal expansion coefficients were applied onto the needle exterior and the end-face of an optical fibre placed in the needle lumen. The excitation light was delivered at the surface by LED arrays and through the embedded optical fibre by a pulsed diode laser to improve the visibility of the needle tip. The performance was validated using an ex-vivo tissue model. An LED-based PA/US imaging system was used for imaging the needle out-of-plane and in-plane insertions over approach angles of 20 deg to 55 deg. The CSNP-PDMS composite conferred substantial visual enhancements on both the needle shaft and the tip, with an average of 1.7- and 1.6-fold improvements in signal-to-noise ratios (SNRs), respectively. With the extended light field involving extracorporeal and interstitial illumination and the highly absorbing coatings, enhanced visualisation of the needle shaft and needle tip was achieved with PA imaging, which could be helpful in current US-guided minimally invasive surgeries.

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