Tracking and mapping in medical computer vision: A review.

As computer vision algorithms increase in capability, their applications in clinical systems will become more pervasive. These applications include: diagnostics, such as colonoscopy and bronchoscopy; guiding biopsies, minimally invasive interventions, and surgery; automating instrument motion; and providing image guidance using pre-operative scans. Many of these applications depend on the specific visual nature of medical scenes and require designing algorithms to perform in this environment. In this review, we provide an update to the field of camera-based tracking and scene mapping in surgery and diagnostics in medical computer vision. We begin with describing our review process, which results in a final list of 515 papers that we cover. We then give a high-level summary of the state of the art and provide relevant background for those who need tracking and mapping for their clinical applications. After which, we review datasets provided in the field and the clinical needs that motivate their design. Then, we delve into the algorithmic side, and summarize recent developments. This summary should be especially useful for algorithm designers and to those looking to understand the capability of off-the-shelf methods. We maintain focus on algorithms for deformable environments while also reviewing the essential building blocks in rigid tracking and mapping since there is a large amount of crossover in methods. With the field summarized, we discuss the current state of the tracking and mapping methods along with needs for future algorithms, needs for quantification, and the viability of clinical applications. We then provide some research directions and questions. We conclude that new methods need to be designed or combined to support clinical applications in deformable environments, and more focus needs to be put into collecting datasets for training and evaluation.

The current state of autonomous suturing: a systematic review.

BACKGROUND: Robotic technology is an important tool in surgical innovation, with robots increasingly being used in the clinical setting. Robots can be used to enhance accuracy, perform remote actions, or to automate tasks. One such surgical task is suturing, a repetitive, fundamental component of surgery that can be tedious and time consuming. Suturing is a promising automation target because of its ubiquity, repetitive nature, and defined constraints. This systematic review examines research to date on autonomous suturing. METHODS: A systematic review of the literature focused on autonomous suturing was conducted in accordance with PRISMA guidelines. RESULTS: 6850 articles were identified by searching PubMed, Embase, Compendex, and Inspec. Duplicates and non-English articles were removed. 4389 articles were screened and 4305 were excluded. Of the 84 remaining, 43 articles did not meet criteria, leaving 41 articles for final review. Among these, 34 (81%) were published after 2014. 31 (76%) were published in an engineering journal9 in a robotics journal, and 1 in a medical journal. The great majority of articles (33, 80%) did not have a specific clinical specialty focus, whereas 6 (15%) were focused on applications in MIS/laparoscopic surgery and 2 (5%) on applications in ophthalmology. Several suturing subtasks were identified, including knot tying, suture passing/needle insertion, needle passing, needle and suture grasping, needle tracking/kinesthesia, suture thread detection, suture needle shape production, instrument assignment, and suture accuracy. 14 articles were considered multi-component because they referred to several previously mentioned subtasks. CONCLUSION: In this systematic review exploring research to date on autonomous suturing, 41 articles demonstrated significant progress in robotic suturing. This summary revealed significant heterogeneity of work, with authors focused on different aspects of suturing and a multitude of engineering problems. The review demonstrates increasing academic and commercial interest in surgical automation, with significant technological advances toward feasibility.

Tracking the time-course of spoken word recognition of Cantonese Chinese in sentence context: Evidence from eye movements.

In this study, we conducted an eye-tracking experiment to investigate the effects of sentence context and tonal information on spoken word recognition processes in Cantonese Chinese. We recruited 60 native Cantonese listeners to participate in the eye-tracking experiment. The target words (phonologically similar words) were manipulated to either (1) a congruent context or (2) an incongruent context in the experiment. The resulting eye-movement patterns in the incongruent context condition clearly revealed that (1) sentence context produced a garden-path effect in the initial stage of the spoken word recognition processes and then (2) the lexical tone of the word (bottom-up information) overrode the contextual effects to help listeners to discriminate between different similar-sounding words during lexical access. In conclusion, the patterns of eye-tracking data show the interactive processes between the lexical tone (an acoustic cue within a Cantonese word) and sentence context played in different phases to the spoken word recognition of Cantonese Chinese.

A case series of appendicitis and pseudo-appendicitis in a paediatric intensive care unit.

INTRODUCTION: Appendicitis is a common childhood condition that can be diagnostically challenging. Severe cases may necessitate support in the critical or intensive care unit. These "critical appendicitis diagnoses" have rarely been described. CASE DESCRIPTION: We retrospective reviewed the PICU database of the Hong Kong Children's Hospital and identified cases of suspected and confirmed appendicitis. Clinical features, radiologic findings and final diagnosis of each case were summarized and reported in this case series. We review six anonymized cases of appendicitis managed in a paediatric intensive care unit (PICU) to illustrate the different age spectrum and clinical manifestations of the condition. Rupture of the inflamed appendix, peritonitis and pancreatitis were some of the complications encountered. Crohn disease was found in one case as an underlying diagnosis. Also, one girl clinically diagnosed with appendicitis was found to be a case of ruptured hepatoblastoma with no appendicitis (i.e., pseudoappendicitis). CONCLUSION: Prompt diagnosis, surgical removal of the inflamed appendix, and use of appropriate antimicrobials when indicated are essential in reducing mortality and morbidity associated with severe appendicitis. Significant premorbid conditions such as acute myeloid leukemia, mitochondrial encephalopathy lactic acidosis syndrome (MELAS), inflammatory bowel disease and complications may be present in patients needing intensive care as is illustrated in the present cases. Pseudoappendicitis is an important differential diagnosis. Imaging is crucial and useful in establishing and confirming the diagnosis of appendicitis and pseudo-appendicitis in these PICU cases.

Artificial intelligence meets medical robotics.

Artificial intelligence (AI) applications in medical robots are bringing a new era to medicine. Advanced medical robots can perform diagnostic and surgical procedures, aid rehabilitation, and provide symbiotic prosthetics to replace limbs. The technology used in these devices, including computer vision, medical image analysis, haptics, navigation, precise manipulation, and machine learning (ML) , could allow autonomous robots to carry out diagnostic imaging, remote surgery, surgical subtasks, or even entire surgical procedures. Moreover, AI in rehabilitation devices and advanced prosthetics can provide individualized support, as well as improved functionality and mobility (see the figure). The combination of extraordinary advances in robotics, medicine, materials science, and computing could bring safer, more efficient, and more widely available patient care in the future. -Gemma K. Alderton.

ORRN: An ODE-Based Recursive Registration Network for Deformable Respiratory Motion Estimation With Lung 4DCT Images.

OBJECTIVE: Deformable Image Registration (DIR) plays a significant role in quantifying deformation in medical data. Recent Deep Learning methods have shown promising accuracy and speedup for registering a pair of medical images. However, in 4D (3D + time) medical data, organ motion, such as respiratory motion and heart beating, can not be effectively modeled by pair-wise methods as they were optimized for image pairs but did not consider the organ motion patterns necessary when considering 4D data. METHODS: This article presents ORRN, an Ordinary Differential Equations (ODE)-based recursive image registration network. Our network learns to estimate time-varying voxel velocities for an ODE that models deformation in 4D image data. It adopts a recursive registration strategy to progressively estimate a deformation field through ODE integration of voxel velocities. RESULTS: We evaluate the proposed method on two publicly available lung 4DCT datasets, DIRLab and CREATIS, for two tasks: 1) registering all images to the extreme inhale image for 3D+t deformation tracking and 2) registering extreme exhale to inhale phase images. Our method outperforms other learning-based methods in both tasks, producing the smallest Target Registration Error of 1.24 mm and 1.26 mm, respectively. Additionally, it produces less than 0.001% unrealistic image folding, and the computation speed is less than 1 s for each CT volume. CONCLUSION: ORRN demonstrates promising registration accuracy, deformation plausibility, and computation efficiency on group-wise and pair-wise registration tasks. SIGNIFICANCE: It has significant implications in enabling fast and accurate respiratory motion estimation for treatment planning in radiation therapy or robot motion planning in thoracic needle insertion.

Cross-situational word learning of Cantonese Chinese.

In this study, we recruited 60 native Cantonese speakers to participate in a standard cross-situational word-learning task to explore the cross-situational learning effects of minimal word pairs in Cantonese Chinese. In the cross-situational word-learning task, four different types of word pairs were used: (1) a non-minimal word pair [N]; (2) a consonant minimal word pair [C]; (3) a rime minimal word pair [R]; and (4) a tone minimal word pair [T]. The results showed that the participants could learn the word-referent mapping for all word-pair types, but they performed better on the N and T types than on the other two (i.e., C and R). Together with other previous evidence, these findings suggest that Cantonese language learners can learn and encode those phonetic details while they learn the word-referent co-occurrence probabilities. The results also suggested that the tonal information seemed to be more important than the other phonological components in Cantonese Chinese word learning.

The foreign language effects on strategic behavior games.

The present study examined foreign language effects on the decisions made in a series of strategic behavioral games (e.g., the Prisoner's Dilemma, the Oligopolistic Competition, and the Volunteer's Dilemma). We recruited 154 native Chinese-speaking university students, with English as their second language, as participants. They were asked to make decisions while playing four simple behavioral games in either Chinese or English language version and to complete a Language History Questionnaire. The results showed that 1) the participants in each language group performed differently in the Prisoner's Dilemma Game and in one condition of the Volunteer's Dilemma Game which involved a relatively high level of uncertainty; and 2) foreign language proficiency, frequency of application and cultural identity triggered by the corresponding foreign language moderated the foreign language effects. This pattern of results is consistent with the Cultural Accommodation Hypothesis and the risk-aversion preference to use one's native language.

Psychometric properties of the Chinese version of procrastination assessment scale for students.

The procrastination assessment scale for students (PASS) has been used widely in evaluating the patterns of university students' procrastination on academic tasks and their procrastination behavior. The present study validated the psychometric properties of a Chinese version of the PASS (PASS-C) by recruiting two representative independent sample of Hong Kong Chinese university students (S1 used in the EFA study: 506; S2 used in the CFA study: 506). The results confirmed that this modified Chinese version is a valid and appropriate tool to assess university students' procrastination tendencies in Chinese educational settings.

Mixed reality surgical mentoring of combat casualty care related procedures in a perfused cadaver model: Initial results of a randomized feasibility study.

BACKGROUND: Most telemedicine modalities have limited ability to enhance procedural and operative care. We developed a novel system to provide synchronous bidirectional expert mixed reality-enabled virtual procedural mentoring. In this feasibility study, we evaluated mixed reality mentoring of combat casualty care related procedures in a re-perfused cadaver model. METHODS: Novices received real-time holographic mentoring from experts using augmented reality via Hololens (Microsoft Inc, Redmond, WA). The experts maintained real-time awareness of the novice's operative environment using virtual reality via HTC-Vive (HTC Corp, Xindian District, Taiwan). Additional cameras (both environments) and novel software created the immersive, shared, 3-dimensional mixed reality environment in which the novice and expert collaborated. The novices were prospectively randomized to either mixed reality or audio-only mentoring. Blinded experts independently evaluated novice procedural videos using a 5-point Likert scale-based questionnaire. Nonparametric variables were evaluated using the Wilcoxon rank-sum test and comparisons using the χ2 analysis; significance was defined at P < .05. RESULTS: Surgeon and nonsurgeon novices (14) performed 69 combat casualty care-related procedures (38 mixed reality, 31 audio), including various vascular exposures, 4-compartment lower leg fasciotomy, and emergency neurosurgical procedures; 85% were performed correctly with no difference in either group. Upon video review, mixed reality-mentored novices showed no difference in procedural flow and forward planning (3.67 vs 3.28, P = .21) or the likelihood of performing individual procedural steps correctly (4.12 vs 3.59, P = .06). CONCLUSION: In this initial feasibility study, our novel mixed reality-based mentoring system successfully facilitated the performance of a wide variety of combat casualty care relevant procedures using a high fidelity re-perfused cadaver model. The small sample size and limited variety of novice types likely impacted the ability of holographically mentored novices to demonstrate improvement over the audio-only control group. Despite this, using virtual, augmented, and mixed reality technologies for procedural mentoring demonstrated promise, and further study is needed.

Remote telesurgery in humans: a systematic review.

BACKGROUND: Since the conception of robotic surgery, remote telesurgery has been a dream upon which incredible technological advances haven been built. Despite the considerable enthusiasm for, there have been few published studies of remote telesurgery on humans. METHODS: We performed a systematic review of the English literature (PubMed, EMbase, Inspec & Compendex and Web of Science) to report studies of remote telesurgery in humans. Keywords included telesurgery, remote surgery, long-distance surgery, and telerobotics. Subjects had to be human (live patients or cadavers). The operating surgeon had to be remote from the patient, separated by more than one kilometer. The article had to explicitly report the use of a long-distance telerobotic technique. Articles that focused on telepresence or tele-mentoring were excluded. RESULTS: The study included eight articles published from 2001 to 2020. One manuscript (1 subject) described remote surgery on a cadaver model, and the other seven were on live humans (72 subjects). Procedure types included percutaneous, endovascular, laparoscopic, and transoral. Communication methods varied, with the first report using a telephone line and the most recent studies using a 5G network. Six of the studies reported signal latency as a single value and it ranged from 28 ms to 280 ms. CONCLUSIONS: Few studies have described remote telesurgery in humans, and there is considerable variability in robotic and communication methods. Future efforts should work to improve reporting of signal latency and follow careful research methodology.

Cognitive Consequences of Bilingualism and Multilingualism: Cross-Linguistic Influences.

Bilingualism and multilingualism are common in almost all communities worldwide today. Research studies on the psycholinguistics of bilingualism and multilingualism in East Asia region has developed tremendously in the past 20 years. Along with the new methodologies, innovative approaches, and the development of those state-of-the-art technologies (Altarriba and Heredia (eds) in An introduction to bilingualism: principles and processes, Routledge, 2018), a lot of new research findings on this line of research have been reported.

Working memory and lexical ambiguity resolution in Cantonese Chinese.

The present study examined how working memory functions in the underlying mechanism of the lexical disambiguation process (in activation approach or in inhibition approach). We recruited sixty native Cantonese listeners to participate in two experimental tasks: (a) a Cantonese-version reading span task to measure their working memory (WM) capacity and (b) a standard cross-modal priming task to measure the lexical disambiguation time. The results revealed that (1) the underlying mechanism of the disambiguation process seemed favorable for an inhibition approach and (2) the frequency of the individual meanings of the ambiguous words and the numbers of their meanings might interact with the WM capacity during lexical access, particularly for the low-WM span group.

Compensatory motion scaling for time-delayed robotic surgery.

BACKGROUND: Round trip signal latency, or time delay, is an unavoidable constraint that currently stands as a major barrier to safe and efficient remote telesurgery. While there have been significant technological advancements aimed at reducing the time delay, studies evaluating methods of mitigating the negative effects of time delay are needed. Herein, we explored instrument motion scaling as a method to improve performance in time-delayed robotic surgery. METHODS: This was a robotic surgery user study using the da Vinci Research Kit system. A ring transfer task was performed under normal circumstances (no added time delay), and with 250 ms, 500 ms, and 750 ms delay. Robotic instrument motion scaling was modulated across a range of values (- 0.15, - 0.1, 0, + 0.1, + 0.15), with negative values indicating less instrument displacement for a given amount of operator movement. The primary outcomes were task completion time and total errors. Three-dimensional instrument movement was compared against different motion scales using dynamic time warping to demonstrate the effects of scaling. RESULTS: Performance declined with increasing time delay. Statistically significant increases in task time and number of errors were seen at 500 ms and 750 ms delay (p < 0.05). Total errors were positively correlated with task time on linear regression (R = 0.79, p < 0.001). Under 750 ms delay, negative instrument motion scaling improved error rates. Negative motion scaling trended toward improving task times toward those seen in non-delayed scenarios. Improvements in instrument path motion were seen with the implementation of negative motion scaling. CONCLUSIONS: Under time-delayed conditions, negative robotic instrument motion scaling yielded fewer surgical errors with slight improvement in task time. Motion scaling is a promising method of improving the safety and efficiency of time-delayed robotic surgery and warrants further investigation.

Scalable tactile sensor arrays on flexible substrates with high spatiotemporal resolution enabling slip and grip for closed-loop robotics.

We report large-scale and multiplexed tactile sensors with submillimeter-scale shear sensation and autonomous and real-time closed-loop grip adjustment. We leveraged dual-gate piezoelectric zinc oxide (ZnO) thin-film transistors (TFTs) fabricated on flexible substrates to record normal and shear forces with high sensitivity over a broad range of forces. An individual ZnO TFT can intrinsically sense, amplify, and multiplex force signals, allowing ease of scalability for multiplexing from hundreds of elements with 100-µm spatial and sub-10-ms temporal resolutions. Notably, exclusive feedback from the tactile sensor array enabled rapid adjustment of grip force to slip, enabling the direct autonomous robotic tactile perception with a single modality. For biomedical and implantable device applications, pulse sensing and underwater flow detection were demonstrated. This robust technology, with its reproducible and reliable performance, can be immediately translated for use in industrial and surgical robotics, neuroprosthetics, implantables, and beyond.

Stroke Encoding Processes of Chinese Character During Sentence Reading.

The present study was conducted to examine whether traditional and simplified Chinese readers (TCRs and SCRs) differed in stroke encoding in character processing by an eye-tracking experiment. We recruited 66 participants (32 TCRs and 34 SCRs) to read sentences comprising characters with different proportions and types of strokes removed in order to explore whether any visual complexity effect existed in their processing of simplified and traditional Chinese characters. The present study found a cross-script visual complexity effect and that SCRs were more influenced by visual complexity change in lexical access than were TCRs. In addition, the stroke-order effect appeared to be more salient for TCRs than for SCRs.

Clinical and radiographic outcomes with a posteriorly augmented glenoid for Walch B2, B3, and C glenoids in reverse total shoulder arthroplasty.

OBJECTIVE: The purpose of this study is to quantify the clinical and radiographic outcomes of patients with severe posterior glenoid wear who were treated with reverse total shoulder arthroplasty (rTSA) and a posterior augmented baseplate. METHODS: A total of 67 primary rTSA patients with osteoarthritis and posterior glenoid wear were treated with an 8° posterior augmented glenoid baseplate. All patients had a Walch B2, B3, or C glenoid, 2-year minimum follow-up, and mean follow-up of 40 months. All patients were scored preoperatively and at the latest follow-up using 5 clinical outcome metrics; active range of motion was also measured. A Student's 2-tailed, unpaired t-test quantified differences in outcomes, where P < .05 denoted significance. RESULTS: All patients experienced significant improvements in pain and function after primary rTSA with a posterior augmented glenoid baseplate. Three complications were reported for a rate of 4.5%; no cases of aseptic glenoid loosening occurred. A total of 90% of patients exceeded the minimal clinically important difference threshold, and 80% of patients exceeded the substantial clinical benefit threshold for each clinical outcome metric and range of motion measure. No differences in outcomes or complications were observed between Walch B2 and B3 patients, demonstrating that this full-wedge posterior augmented baseplate was equally good in each type of glenoid deformity. DISCUSSION: Primary rTSA patients with Walch B2, B3, and C glenoids who received an 8° posterior augmented glenoid baseplate experienced excellent clinical and radiographic outcomes with a low complication rate and no reports of aseptic glenoid loosening at a mean follow-up of 40 months.

Psychometric properties of a Chinese version of the Brief Young Adult Alcohol Consequences Questionnaire (B-YAACQ).

AIM: This study evaluated the psychometric properties of the Chinese version of the Brief Young Adult Alcohol Consequences Questionnaire (B-YAACQ). METHOD: In this study, 1616 Chinese university students (male = 58.66%; Mage = 19.88) reporting past-year drinking experience voluntarily completed an anonymous questionnaire. Rasch analysis, reliability analysis, and linear modeling were performed to examine the psychometric properties of the Chinese version of B-YAACQ. RESULTS: Results of Rasch analysis and reliability analysis supported the assumption of uni-dimensionality, local independence, and internal consistency of the 24-item B-YAACQ in our Chinese sample. However, six items had marginal outfit statistics and/or potential gender bias; therefore, a model with 18 items was also tested after removing these items. The 18-item model showed excellent fit to the uni-dimensional model with no gender bias. However, the Pearson correlation between the 24-item and 18-item versions was r = 0.98, suggesting highly similar measurement. Both versions demonstrated concurrent validity through positive association with the Alcohol Use Disorder Identification Test (AUDIT) subscales, even after controlling for the effects of age and gender. CONCLUSION: This study is the first to validate a measurement tool for negative drinking consequences for university students in China. Despite some limitations, the original 24-item B-YAACQ was shown to have satisfactory psychometric properties when applied to Chinese university students. We recommend the shorter 18-item version without significant gender bias for testing gender differences.