Purpose: Surgery scene understanding with tool-tissue interaction recognition and automatic report generation can play an important role in intra-operative guidance, decision-making and postoperative analysis in robotic surgery. However, domain shifts between different surgeries with inter and intra-patient variation and novel instruments' appearance degrade the performance of model prediction. Moreover, it requires output from multiple models, which can be computationally expensive and affect real-time performance. Methodology: A multi-task learning (MTL) model is proposed for surgical report generation and tool-tissue interaction prediction that deals with domain shift problems. The model forms of shared feature extractor, mesh-transformer branch for captioning and graph attention branch for tool-tissue interaction prediction. The shared feature extractor employs class incremental contrastive learning (CICL) to tackle intensity shift and novel class appearance in the target domain. We design Laplacian of Gaussian (LoG) based curriculum learning into both shared and task-specific branches to enhance model learning. We incorporate a task-aware asynchronous MTL optimization technique to fine-tune the shared weights and converge both tasks optimally. Results: The proposed MTL model trained using task-aware optimization and fine-tuning techniques reported a balanced performance (BLEU score of 0.4049 for scene captioning and accuracy of 0.3508 for interaction detection) for both tasks on the target domain and performed on-par with single-task models in domain adaptation. Conclusion: The proposed multi-task model was able to adapt to domain shifts, incorporate novel instruments in the target domain, and perform tool-tissue interaction detection and report generation on par with single-task models.

手术中的视觉问题回答（VQA）在很大程度上没有探索。专家外科医生稀缺，经常被临床和学术工作负载超负荷。这种超负荷通常会限制他们从患者，医学生或初级居民与手术程序有关的时间回答问卷。有时，学生和初级居民也不要在课堂上提出太多问题以减少干扰。尽管计算机辅助的模拟器和过去的手术程序记录已经可以让他们观察和提高技能，但他们仍然非常依靠医学专家来回答他们的问题。将手术VQA系统作为可靠的“第二意见”可以作为备份，并减轻医疗专家回答这些问题的负担。缺乏注释的医学数据和特定于域的术语的存在限制了对手术程序的VQA探索。在这项工作中，我们设计了一项外科VQA任务，该任务根据外科手术场景回答有关手术程序的问卷。扩展MICCAI内窥镜视觉挑战2018数据集和工作流识别数据集，我们介绍了两个具有分类和基于句子的答案的手术VQA数据集。为了执行手术VQA，我们采用视觉文本变压器模型。我们进一步介绍了一个基于MLP的剩余Visualbert编码器模型，该模型可以在视觉令牌和文本令牌之间进行相互作用，从而改善了基于分类的答案的性能。此外，我们研究了输入图像贴片数量和时间视觉特征对分类和基于句子的答案中模型性能的影响。

Context-aware decision support in the operating room can foster surgical safety and efficiency by leveraging real-time feedback from surgical workflow analysis. Most existing works recognize surgical activities at a coarse-grained level, such as phases, steps or events, leaving out fine-grained interaction details about the surgical activity; yet those are needed for more helpful AI assistance in the operating room. Recognizing surgical actions as triplets of <instrument, verb, target> combination delivers comprehensive details about the activities taking place in surgical videos. This paper presents CholecTriplet2021: an endoscopic vision challenge organized at MICCAI 2021 for the recognition of surgical action triplets in laparoscopic videos. The challenge granted private access to the large-scale CholecT50 dataset, which is annotated with action triplet information. In this paper, we present the challenge setup and assessment of the state-of-the-art deep learning methods proposed by the participants during the challenge. A total of 4 baseline methods from the challenge organizers and 19 new deep learning algorithms by competing teams are presented to recognize surgical action triplets directly from surgical videos, achieving mean average precision (mAP) ranging from 4.2% to 38.1%. This study also analyzes the significance of the results obtained by the presented approaches, performs a thorough methodological comparison between them, in-depth result analysis, and proposes a novel ensemble method for enhanced recognition. Our analysis shows that surgical workflow analysis is not yet solved, and also highlights interesting directions for future research on fine-grained surgical activity recognition which is of utmost importance for the development of AI in surgery.