Dual-modality fibre optic probe for simultaneous ablation and ultrasound imaging

Abstract

All-optical ultrasound (OpUS) is an emerging high resolution imaging paradigm utilising optical fibres. This allows both therapeutic and imaging modalities to be integrated into devices with dimensions small enough for minimally invasive surgical applications. Here we report a dual-modality fibre optic probe that synchronously performs laser ablation and real-time all-optical ultrasound imaging for ablation monitoring. The device comprises three optical fibres: one each for transmission and reception of ultrasound, and one for the delivery of laser light for ablation. The total device diameter is < 1 mm. Ablation monitoring was carried out on porcine liver and heart tissue ex vivo with ablation depth tracked using all-optical M-mode ultrasound imaging and lesion boundary identification using a segmentation algorithm. Ablation depths up to 2.1 mm were visualised with a good correspondence between the ultrasound depth measurements and visual inspection of the lesions using stereomicroscopy. This work demonstrates the potential for OpUS probes to guide minimally invasive ablation procedures in real time.

PDMS Composites with Photostable NIR Dyes for B-Mode Ultrasound Imaging

“…The plano-concave microresonator was interrogated with a continuous wave laser (Tunics T100S-HP, Yenista Optics, France) with a tuning range of 1500−1630 nm and a power of 4.5 mW as described in previous studies [8,14]. The laser was connected via a fibre optic circulator which allowed the reflected signal to be detected with a photoreceiver.…”

“…A wide variety of absorbers have been studied, including metallic nanostructures [1,7], graphene [8], candle soot [9,10] and carbon nanotubes [11][12][13]. Typically, polydimethlysiloxane (PDMS) is used as an elastomeric host component due to its large thermal expansion coefficient, which provides efficient photoacoustic conversion [1,8,10,14].…”

“…Here, the ultrasound can be generated at one wavelength via optical absorption within the coating, whilst at other wavelengths light can be transmitted through the coating and be used for a complementary modality such as photoacoustic imaging [7,18] or ablation [14].…”

Suppressing artifacts in the total focusing method using the directivity of laser ultrasound

“…Ultrasonic imaging is intuitive and innocuous, making it one of the most widely used nondestructive evaluation (NDE) techniques [1] . In the past few decades, there has been a transition from NDE to quantitative NDE to help optimize the manufacturing process or improve structural health management [2] .…”

Miniaturised all-optical ultrasound probe for thrombus imaging

“…5,6 Additionally, the use of optical fibres for light delivery allows for miniaturisation of the device and immunity to electromagnetic interference. 7 When integrated into a medical catheter, these devices are well-suited for imaging within the human body, in areas such as intravascular imaging, where space constraints are crucial. Furthermore, OpUS devices utilise low-cost materials and fabrication processes which are ideal for single use devices.…”