Wellcome / EPSRC Centre for Interventional and Surgical Sciences

Congenital syndromes with subtle changes in maxillofacial morphology can pose significant diagnostic challenges, wherein artificial intelligence holds great promise in aiding diagnosis through shape analysis. The authors applied the recently proposed Swap Disentangled Variational Autoencoder (SD-VAE) in diagnosis of Beckwith-Wiedemann syndrome (BWS). The SD-VAE model was trained on a data set primarily comprised of surface 3D head scans [stereophotogrammetry (3D SPG)], gathered using a 3dMD Head System (3dMD LLC). It was also trained on CT scans when available. A total of 72 syndromic scans were used belonging to 56 different BWS patients. Scans of head shapes were pre-processed and annotated with 68 anatomic landmarks. This aided in achieving uniformity between the scans and a template mesh, making a better comparison possible. The SD-VAE model outputs were then visualized in a 2-dimensional space and classified as 'BWS-patient' or 'control'. For each anatomic facial region, the performance of the classification model was evaluated. This allowed us to understand the classification accuracy for each anatomic region as well as calculate the sensitivity and specificity for each region. The model demonstrated perfect diagnostic accuracy for BWS on the test set, with the most characteristic regions being the chin, cheeks, zygoma, eyes, jaw, and supraorbital region. This paper demonstrates how SD-VAE can be applied to 3D head meshes, to quantify the characteristic features of BWS. The authors distinguished BWS-specific features from those of the general population with high diagnostic accuracy. This makes SD-VAE a promising tool for aiding the referral and diagnosis of BWS in the future.

Kirigami, or “jianzhi” in Chinese, is an art in paper‐cutting. Using simple tools like scissors, artisans transform paper into intricate designs featuring flowers, animals, or characters (e.g., “囍”). Nowadays, kirigami has emerged as a particularly promising design strategy in engineering. This method involves creating systematic cut patterns on thin, planar sheets, which enables complex mechanical responses by changing dimensions, thereby offering innovative solutions for the development of metamaterials, soft actuators, and robotic systems. The concept of the integration of ancient art and modern science and technology has injected vitality into the development of many disciplines and become the forefront of interdisciplinary research. This review provides a systematic review of recent progress on the design of kirigami and applications in diverse robotic prototypes. The kirigami begins by classifying into two categories from a compliant mechanism perspective, and then it examines the distinctive mechanical properties that altered by cut patterns, followed by reviewing the design of the two types of kirigami. Next, the kirigami‐inspired kinematic metamaterials is examined. Finally, applications in soft actuators and robotic systems is demonstrated. The integration of design methods, fabrication techniques, materials research, mechanics modeling, and control systems will further advance this emerging field.

BACKGROUND AND OBJECTIVES:Endoscopic skull base surgery aims to reduce surgical morbidity by minimizing tissue manipulation and exposure. However, the anatomic constraints posed by the narrow surgical corridors and constrained operative workspace present technical challenges due to reduced dexterity. This study evaluates the applicability of a novel dexterity-enhancing handheld robot for endoscopic skull base approaches.METHODS:The robotic system is comprised of interchangeable articulated end-effectors coupled to a handheld controller. Two attending skull base neurosurgeons and 2 neurosurgery residents performed 8 skull base approaches on cadaveric specimens, spanning anterior, anterolateral, lateral, posterolateral, and posterior approaches. Conventional instruments were used to expose anatomic landmarks, followed by intraoperative tasks using the handheld robot. Participants were interviewed during the procedures to assess the robot's feasibility (ability to safely reach and perform its objective of manipulating tissue at the operative site) and usefulness (ability to perform desired objectives well).RESULTS:The handheld robotic system was tested across 8 endoscopic skull base approaches, achieving feasibility in all cases. Superior workspace reach compared with standard instruments was demonstrated in 6 of 8 approaches. Tissue manipulation was satisfactory in all approaches. All surgeons reported that the current or a future device prototype could be useful across all 8 approaches. The most frequently cited advantage was the expanded dextrous workspace reach provided by the articulated end-effectors, particularly in approaches with long working channels, such as the endonasal approach. However, the robot encountered difficulties in transcranial approaches (trans-sylvian and subtemporal) due to the lack of shorter, curved shafts, which impaired visualization.CONCLUSION:The handheld robotic system demonstrated applicability across various endoscopic skull base approaches, offering increased dextrous workspace and effective tissue manipulation capabilities. Overall, this study supports the potential of handheld robots in endoscopic skull base surgery while highlighting the need for iterative development to optimize instrument design and functionality.

Minimally invasive surgery offers improved recovery times and reduced complication risk compared with open surgery. However, effective image acquisition probes suitable for deployment in clinical workflows are key to the success of such procedures. Fiber-optic optical ultrasound (OpUS) offers strong potential for interventional image guidance due to its small lateral probe dimensions and high imaging resolution, but to date, such miniature imaging probes have only yielded M-mode (single image line) or still images. Here, we present a motorized actuation approach to fiber-optic interventional OpUS imaging that enables sustained and video-rate imaging while retaining its small form factor. A fabrication method utilizing a commercial laser cutter is presented that yields partially forward-emitting OpUS sources ideally suited for interventional image guidance. These transmitters were incorporated into a miniature imaging probe with a width of just (1.8mm with protective encapsulation) and combined with a linear actuator to synthesize an imaging aperture at the distal end of the probe through manipulation at its proximal end. The presented imaging paradigm achieved real-time, two-dimensional OpUS imaging at frame rates of up to 7Hz and was capable of high-resolution imaging ( axial and lateral). The imaging performance of the presented imaging system was assessed using various imaging phantoms, and its clinical suitability was confirmed by emulating endobronchial OpUS imaging through a commercial bronchoscope. These results constitute the first-ever sustained, real-time dynamic imaging using a side-viewing single-element OpUS probe via rapid actuation, which enables a wide range of applications in minimally invasive surgical guidance.

4D printing provides viable pathways for 3D-printed objects that require morphological, time-dependent adaptations. Among various 4D printing materials, shape-memory polymers (SMPs) are one of the most extensively utilized morphing materials. However, most existing SMPs in 4D printing systems suffer from irreparability and low stretchability due to abundant covalently cross-linked networks. Also, their shape-programming steps typically involve stringent temperature requirements (≥90 ºC) and lack strategies for remote controllability, significantly restricting their applicability. Herein, we report a novel thermoplastic polymer system with self-healing and highly stretchable shape-memory capabilities for digital light processing (DLP)-based 4D printing. This system was attained through the integration of two distinct compositions: a polymer-based framework that acts as the reinforcing phase; and an elastic lubricant featuring hydrogen bonds that facilitates self-healing, high stretchability, and enhanced shape recovery. Additionally, light-responsive capabilities were shown to be effectively achieved by introducing a novel cross-linker functionalized with biomass lignin. The rationally selected safer set of ingredients ensures that our printed shape-memory polymer composites (SMPCs) are biocompatible. We further demonstrate their potential applications in aerospace and healthcare. This work provides a foundation for the design and facilitation of intelligent materials, showcasing excellent properties across multiple fields.

Low-intensity Transcranial Ultrasonic Stimulation (TUS) is a non-invasive brain stimulation technique enabling cortical and deep brain targeting with unprecedented spatial accuracy. Given the high rate of adoption by new users with varying levels of expertise and interdisciplinary backgrounds, practical guidelines are needed to ensure state-of-the-art TUS application and reproducible outcomes. Therefore, the International Transcranial Ultrasonic Stimulation Safety and Standards (ITRUSST) consortium has formed a subcommittee, endorsed by the International Federation of Clinical Neurophysiology (IFCN), to develop recommendations for best practices in human TUS applications. The practical guide presented here provides a brief introduction into ultrasound physics and sonication parameters. It explains the requirements of TUS lab equipment and transducer selection and discusses experimental design and procedures alongside potential confounds and control conditions. Finally, the guide elaborates on essential steps of application planning for stimulation safety and efficacy, as well as considerations when combining TUS with neuroimaging, electrophysiology, or other brain stimulation techniques. We hope that this practical guide to TUS will assist both novice and experienced users in planning and conducting high-quality studies and provide a solid foundation for further advancements in this promising field.