The value of Augmented Reality in surgery - A usability study on laparoscopic liver surgery.

Augmented Reality (AR) is considered to be a promising technology for the guidance of laparoscopic liver surgery. By overlaying pre-operative 3D information of the liver and internal blood vessels on the laparoscopic view, surgeons can better understand the location of critical structures. In an effort to enable AR, several authors have focused on the development of methods to obtain an accurate alignment between the laparoscopic video image and the pre-operative 3D data of the liver, without assessing the benefit that the resulting overlay can provide during surgery. In this paper, we present a study that aims to assess quantitatively and qualitatively the value of an AR overlay in laparoscopic surgery during a simulated surgical task on a phantom setup. We design a study where participants are asked to physically localise pre-operative tumours in a liver phantom using three image guidance conditions - a baseline condition without any image guidance, a condition where the 3D surfaces of the liver are aligned to the video and displayed on a black background, and a condition where video see-through AR is displayed on the laparoscopic video. Using data collected from a cohort of 24 participants which include 12 surgeons, we observe that compared to the baseline, AR decreases the median localisation error of surgeons on non-peripheral targets from 25.8 mm to 9.2 mm. Using subjective feedback, we also identify that AR introduces usability improvements in the surgical task and increases the perceived confidence of the users. Between the two tested displays, the majority of participants preferred to use the AR overlay instead of navigated view of the 3D surfaces on a separate screen. We conclude that AR has the potential to improve performance and decision making in laparoscopic surgery, and that improvements in overlay alignment accuracy and depth perception should be pursued in the future.

Enhanced Surgeons: Understanding the Design of Augmented Reality Instructions for Keyhole Surgery.

It is important to understand how to design AR content for surgical contexts to mitigate the risk of distracting the surgeons. In this work, we test information overlays for AR guidance during keyhole surgery. We performed a preliminary evaluation of a prototype, focusing on the effects of colour, opacity, and information representation. Our work contributes insights into the design of AR guidance in surgery settings and a foundation for future research on visualisation design for surgical AR.

The Effect of Luminance on Depth Perception in Augmented Reality Guided Laparoscopic Surgery.

Depth perception is a major issue in surgical augmented reality (AR) with limited research conducted in this scientific area. This study establishes a relationship between luminance and depth perception. This can be used to improve visualisation design for AR overlay in laparoscopic surgery, providing surgeons a more accurate perception of the anatomy intraoperatively. Two experiments were conducted to determine this relationship. First, an online study with 59 participants from the general public, and second, an in-person study with 10 surgeons as participants. We developed 2 open-source software tools utilising SciKit-Surgery libraries to enable these studies and any future research. Our findings demonstrate that the higher the relative luminance, the closer a structure is perceived to the operating camera. Furthermore, the higher the luminance contrast between the two structures, the higher the depth distance perceived. The quantitative results from both experiments are in agreement, indicating that online recruitment of the general public can be helpful in similar studies. An observation made by the surgeons from the in-person study was that the light source used in laparoscopic surgery plays a role in depth perception. This is due to its varying positioning and brightness which could affect the perception of the overlaid AR. We found that luminance directly correlates with depth perception for both surgeons and the general public, regardless of other depth cues. Future research may focus on comparing different colours used in surgical AR and using a mock operating room (OR) with varying light sources and positions.

Designing Digital COVID-19 Screening: Insights and Deliberations.

Due to the global COVID-19 pandemic, public health control and screening measures have been introduced at healthcare facilities, including those housing our most vulnerable populations. These warning measures situated at hospital entrances are presently labour-intensive, requiring additional staff to conduct manual temperature checks and risk-assessment questionnaires of every individual entering the premises. To make this process more efficient, we present eGate, a digital COVID-19 health-screening smart Internet of Things system deployed at multiple entry points around a children's hospital. This paper reports on design insights based on the experiences of concierge screening staff stationed alongside the eGate system. Our work contributes towards social-technical deliberations on how to improve design and deploy of digital health-screening systems in hospitals. It specifically outlines a series of design recommendations for future health screening interventions, key considerations relevant to digital screening control systems and their implementation, and the plausible effects on the staff who work alongside them.

Nurse, Give Me the News! Understanding Support for and Opposition to a COVID-19 Health Screening System.

Helping the sick and protecting the vulnerable has long been the credo of the health profession. In response to the coronavirus-disease-2019 (COVID-19 pandemic), hospitals and healthcare institutions have rapidly employed public health measures to mitigate patient and staff infection. This paper investigates staff and visitor responses to the COVID-19 eGate health screening system; a self-service technology (SST) which aims to protect health care workers and facilities from COVID-19. Our study evaluates the in situ deployment of the eGate, and employs a System Usability Scale (SUS) and questionnaire (n = 220) to understand staff and visitor's acceptance of the eGate. In detailing the themes relevant to those who advocate for the system and those who oppose it, we contribute towards a more detailed understanding of the use and non-use of health-screening SSTs. We conclude with a series of considerations for the design of future interactive screening systems within hospitals.

Attempts to Attract Eyesight in E-Commerce May Have Negative Effects.

E-commerce shop owners often want to attract user attention to a specific product to enhance the chances of sales, to cross-sell, or up-sell. The way of presenting a recommended item is as important as the recommendation algorithms are to gain that attention. In this study, we examined the following types of highlights: background, shadow, animation, and border, as well as the position of the item in a 5 × 2 grid in a furniture online store, and their relationships with user fixations and user interest. We wanted to verify the effects highlighting had on attracting user attention. Various levels of intensity were considered for each highlight: low, medium, and strong. Methods used for data collection were both implicit and explicit: eye tracking, tracking cart's contents, and a supplementary survey. Experimental results showed that a low-intensity background highlight should be the first-choice solution to best attract user attention in the presented shopping scenario, resulting in the best fixation times and most users' selections. However, in the case of the highest-intensity animations, highlighting seemed to have negative effects; despite successful attempts to attract eyesight and a long fixation time, users did not add the highlighted products to cart.

CAL-Tutor: A HoloLens 2 Application for Training in Obstetric Sonography and User Motion Data Recording.

Obstetric ultrasound (US) training teaches the relationship between foetal anatomy and the viewed US slice to enable navigation to standardised anatomical planes (head, abdomen and femur) where diagnostic measurements are taken. This process is difficult to learn, and results in considerable inter-operator variability. We propose the CAL-Tutor system for US training based on a US scanner and phantom, where a model of both the baby and the US slice are displayed to the trainee in its physical location using the HoloLens 2. The intention is that AR guidance will shorten the learning curve for US trainees and improve spatial awareness. In addition to the AR guidance, we also record many data streams to assess user motion and the learning process. The HoloLens 2 provides eye gaze, head and hand position, ARToolkit and NDI Aurora tracking gives the US probe positions and an external camera records the overall scene. These data can provide a rich source for further analysis, such as distinguishing expert from novice motion. We have demonstrated the system in a sample of engineers. Feedback suggests that the system helps novice users navigate the US probe to the standard plane. The data capture is successful and initial data visualisations show that meaningful information about user behaviour can be captured. Initial feedback is encouraging and shows improved user assessment where AR guidance is provided.

Exploring User Needs in the Development of a Virtual Reality-Based Advanced Life Support Training Platform: Exploratory Usability Study.

BACKGROUND: Traditional methods of delivering Advanced Life Support (ALS) training and reaccreditation are resource-intensive and costly. Interactive simulations and gameplay using virtual reality (VR) technology can complement traditional training processes as a cost-effective, engaging, and flexible training tool. OBJECTIVE: This exploratory study aimed to determine the specific user needs of clinicians engaging with a new interactive VR ALS simulation (ALS-SimVR) application to inform the ongoing development of such training platforms. METHODS: Semistructured interviews were conducted with experienced clinicians (n=10, median age=40.9 years) following a single playthrough of the application. All clinicians have been directly involved in the delivery of ALS training in both clinical and educational settings (median years of ALS experience=12.4; all had minimal or no VR experience). Interviews were supplemented with an assessment of usability (using heuristic evaluation) and presence. RESULTS: The ALS-SimVR training app was well received. Thematic analysis of the interviews revealed five main areas of user needs that can inform future design efforts for creating engaging VR training apps: affordances, agency, diverse input modalities, mental models, and advanced roles. CONCLUSIONS: This study was conducted to identify the needs of clinicians engaging with ALS-SimVR. However, our findings revealed broader design considerations that will be crucial in guiding future work in this area. Although aligning the training scenarios with accepted teaching algorithms is important, our findings reveal that improving user experience and engagement requires careful attention to technology-specific issues such as input modalities.

Synthesizing Multiple Stakeholder Perspectives on Using Virtual Reality to Improve the Periprocedural Experience in Children and Adolescents: Survey Study.

BACKGROUND: Virtual reality (VR) technology is a powerful tool for augmenting patient experience in pediatric settings. Incorporating the needs and values of stakeholders in the design of VR apps in health care can contribute to better outcomes and meaningful experiences for patients. OBJECTIVE: We used a multiperspective approach to investigate how VR apps can be designed to improve the periprocedural experiences of children and adolescents, particularly those with severe anxiety. METHODS: This study included a focus group (n=4) and a survey (n=56) of clinicians. Semistructured interviews were conducted with children and adolescents in an immunization clinic (n=3) and perioperative setting (n=65) and with parents and carers in an immunization clinic (n=3) and perioperative setting (n=35). RESULTS: Qualitative data were examined to determine the experience and psychological needs and intervention and design strategies that may contribute to better experiences for children in three age groups (4-7, 8-11, and 12-17 years). Quantitative data were used to identify areas of priority for future VR interventions. CONCLUSIONS: We propose a set of ten design considerations for the creation of future VR experiences for pediatric patients. Enhancing patient experience may be achieved by combining multiple VR solutions through a holistic approach considering the roles of clinicians and carers and the temporality of the patient's experience. These situations require personalized solutions to fulfill the needs of pediatric patients before and during the medical procedure. In particular, communication should be placed at the center of preprocedure solutions, while emotional goals can be embedded into a procedure-focused VR app to help patients shift their focus in a meaningful way to build skills to manage their anxiety.

IGF-1 is an independent risk factor for anemia in diabetic pre-dialysis patients.

BACKGROUND: We investigated whether the presence of diabetes mellitus (DM) was related to the degree of the anemia in predialytic patients with renal failure and what was the most relevant factor for anemia in patients with chronic kidney disease (CKD) from DM (DM-CKD). METHODS: Seventy seven patients (47 predialytic patients with long-term type 2 DM (DM-CKD) and 30 predialytic patients whose disease was due to other causes (non DM-CKD)) were enrolled in this study. The blood hemoglobin (Hb) and hematocrit, and the creatinine, ferritin, vitamin B12, folate, iron, LDH, albumin, hs-CRP, intact-PTH, erythropoietin, leptin and Insulin-like growth factor I (IGF-1) levels were measured using standard methods. The estimated GFR was calculated using the abbreviated MDRD equation. RESULTS: The two groups did not significantly differ as to age, gender, the serum creatinine level and the inflammatory status. The Hb level was significantly lower in the DM-CKD patients than that in the non DM-CKD patients (8.5+/-1.7 g/dL vs 9.6+/-1.6 g/dL, respectively, p=0.01). The Hb level was significantly lower in the DM-CKD patients who were being treated with ACE inhibitors (the DM-ACE patients) than that in the non DM-CKD patients who were being treated with ACE inhibitors (the non DM-ACE patients) (8.5+/-1.5 g/dL vs 10.8+/-1.6 g/dL, respectively, p=0.001). Multiple regression analysis indicated that serum IGF-1 concentration was independently associated with the Hb level (beta=0.425, p=0.02) in the DM-CKD patients. CONCLUSIONS: The Hb concentration was significantly lower in the DM-CKD patients than that in the non DM-CKD patients. It was independently associated with the serum IGF-1 concentration in the DM-CKD patients.

Association between serum n-terminal pro-brain natriuretic peptide concentration and left ventricular dysfunction and extracellular water in continuous ambulatory peritoneal dialysis patients.

BACKGROUND: This study investigated the association between serum N-terminal pro-brain natriuretic peptide (NT-pro-BNP) levels and extracellular water (ECW%) and left ventricular (LV) dysfunction in continuous ambulatory peritoneal dialysis (CAPD) patients. METHODS: The study involved 30 stable CAPD patients: 14 males, 16 females; mean age 52 +/- 14 years; mean CAPD duration 34 +/- 12 months; 12 with diabetes mellitus (DM) and 18 non-DM. Serum NT-pro-BNP levels were determined using electrochemiluminescence immunoassay. Baseline echocardiography was performed using a Hewlett-Packard Sonos 1000 (Andover, Massachusetts, USA) device equipped with a 2.25-MHz probe, allowing M-mode, two-dimensional, and pulsed Doppler measurements. Left ventricular mass index (LVMI) was calculated according to the Penn formula. A multifrequency bioimpedance analyzer was used; ECW% was calculated as a percentage of total body water and was considered the index of volume load. RESULTS: (1) Serum NT-pro-BNP level, ECW%, LVMI, and LV ejection fraction in CAPD patients were 3924 (240 - 74460) pg/mL, 36.7% +/- 2.2%, 158 +/- 48 g/m2, and 60.5% +/-11.2%, respectively. (2) Patients were divided into three tertiles (10 patients each) according to their serum NT-proBNP concentration [1st tertile 1168 (240 - 2096), 2nd tertile 4856 (2295 - 20088), 3rd tertile 35012 (20539 -74460) pg/mL]. The tertiles did not differ significantly in terms of age, sex, presence of DM, body mass index, or PD duration. Patients in the 3rd tertile (highest serum NT-proBNP concentration) had the highest LVMI (126 +/- 45 vs 160 +/-41 vs 200 +/- 23 g/m2 for 1st, 2nd, 3rd tertiles, respectively) and the lowest LV ejection fraction (66% +/- 11% vs 62% +/-6% vs 55% +/- 9%). ECW% did not differ significantly between tertiles (35.5% +/- 2.0% vs 37.5% +/- 2.0% vs 36.5% +/-2.0%). (3) In CAPD patients, serum NT-pro-BNP levels correlated positively with LVMI (r = 0.628, p = 0.003) and negatively with LV ejection fraction (r = -0.479, p = 0.033). Serum NT-pro-BNP levels did not correlate with ECW% (r = 0.227, p = 0.25). (4) Stepwise regression analysis showed that LV ejection fraction (beta = -0.610, p = 0.015) and LVMI (beta = 0.415, p = 0.007) were independently associated with the serum NT-pro-BNP concentration. CONCLUSIONS: There was no link between ECW% and serum NT-pro-BNP concentration. Thus, serum NT-pro-BNP levels may not provide objective information with respect to pure hydration status in CAPD patients. In contrast, serum NT-pro-BNP levels were linked to LVMI and LV ejection fraction in CAPD patients. Therefore, while the serum NT-proBNP concentration might not be a useful clinical marker for extracellular fluid volume load, it appears useful for evaluating LV hypertrophy and LV dysfunction in CAPD patients.

The effects of low calcium dialysate on arterial compliance and vasoactive substances in patients with hemodialysis.

BACKGROUND: Considering that dialysate calcium concentration is potentially a main determinant of the serum ionized calcium level and vasoconstriction is associated with the blood calcium concentration, we conducted a study to evaluate the interdialytic effects of treatment with a low calcium dialysate (LdCa, 1.25 mmol/L) on the changes in arterial compliance (AC), blood pressure (BP), biochemical parameters and vasoactive substances. METHODS: Eight hemodialysis (HD) patients (mean age: 46.8 +/- 13.7 years, 4 men and 4 women) were included in the study. AC, systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), mean arterial pressure (MAP), serum ionized Ca, intact-PTH, serum nitric oxide and aldosterone were compared after 10 sessions of treatment with LdCa. Right carotid artery diameter was measured 3 times using a real time B-mode ultrasound imager (Hewlett-Packard Sonos 2000) and AC was calculated using the Hayoz method. RESULTS: 1) AC was recorded as 0.140 (0.080-0.170) mm2/kPa at the baseline (1.75 mmol/L calcium dialysate), 0.170 (0.050-0.290) mm2/kPa after LdCa treatment (p < 0.05 versus baseline), and 0.140 (0.070-0.250) mm2/kPa following the HdCa treatment (p < 0.05 versus LdCa data). 2) MAP and PP were calculated at 114.12 +/- 10.56 mmHg and 63.50 +/- 10.87 mmHg at the baseline; 98.37 +/- 15.14 mmHg and 56.50 +/- 5.95 mmHg after LdCa treatment (p < 0.05 versus baseline); and 115.75 +/- 9.64 mmHg and 62.00 +/- 15.71 mmHg following HdCa treatment (p < 0.05 versus LdCa data). 3) Serum ionized Ca and intact-PTH were measured at 4.66 +/- 0.40 mg/dL and 25.08 +/- 16.44 pg/mL at the baseline; 4.45 +/- 0.28 mg/dL and 90.71 +/- 27.03 pg/mL after LdCa treatment (p < 0.05 versus baseline); and 4.65 0.43 mg/dL and 24.08 +/- 15.44 pg/mL following HdCa treatment (p < 0.05 versus LdCa data). 4) Serum aldosterone concentration was 300.8 (65.5-836.1) pg/mL at the baseline, and 220.2 (42.8-527.9) pg/mL after LdCa treatment (p < 0.05). CONCLUSION: There were favorable changes in AC, BP, biochemical parameters after treatment with LdCa. These changes may be associated with the reduction in serum ionized calcium and decreased serum aldosterone concentration.