New Surgical Needle Can Send Real-Time Ultrasound Images to Surgeons

A diagram of a new needle                                                               NATURE

A collaboration between researchers at UCL and Queen Mary University of London (QMUL) has led to the development of a new optical ultrasound needle that allows heart tissue to be imaged in real-time during keyhole procedures. The new technology gives doctors a high resolution image of soft heart tissue up to 2.5 cm in front of the needle when inside the body. The needle has been successfully tested on surgery on pigs and has the potential to make surgery safer and more accurate. Currently doctors have to rely on preoperative imaging scans and external ultrasound probes to give help them visualize the soft tissues being operated in during keyhole surgery as the surgery incision hole is too small to allow for imaging equipment as well. The breakthrough of combining the imaging technology with the surgical tools is a game changer.

Source:  NATURE

High-frequency ultrasound imaging can provide exquisite visualizations of tissue to guide minimally invasive procedures. Here, we demonstrate that an all-optical ultrasound transducer, through which light guided by optical fibers is used to generate and receive ultrasound, is suitable for real-time invasive medical imaging in vivo. Broad-bandwidth ultrasound generation was achieved through the photoacoustic excitation of a multiwalled carbon nanotube-polydimethylsiloxane composite coating on the distal end of a 300-μm multi-mode optical fiber by a pulsed laser. The interrogation of a high-finesse Fabry–Pérot cavity on a single-mode optical fiber by a wavelength-tunable continuous-wave laser was applied for ultrasound reception. This transducer was integrated within a custom inner transseptal needle (diameter 1.08 mm; length 78 cm) that included a metallic septum to acoustically isolate the two optical fibers. The use of this needle within the beating heart of a pig provided unprecedented real-time views (50 Hz scan rate) of cardiac tissue (depth: 2.5 cm; axial resolution: 64 μm) and revealed the critical anatomical structures required to safely perform a transseptal crossing: the right and left atrial walls, the right atrial appendage, and the limbus fossae ovalis. This new paradigm will allow ultrasound imaging to be integrated into a broad range of minimally invasive devices in different clinical contexts.

The study has been published in Light: Science & Applications. Dr Malcolm Finlay