Monitoring with head-mounted displays in general anesthesia: a clinical evaluation in the operating room

Current Clinical and Educational Uses of Immersive Reality in Anesthesia: Narrative Review

BACKGROUND

The concept of immersive reality (IR), an umbrella term that encompasses virtual reality, augmented reality, and mixed reality, has been established within the health care realm as a potentially valuable tool with numerous applications in both medical education and patient care.

OBJECTIVE

This review aimed to introduce anesthesiologists to the emerging and rapidly evolving literature on IR, its use in anesthesia education, and its transferability into the clinical context.

METHODS

A review of the relevant literature was conducted using the PubMed database from inception to July 5, 2023. Additional references were identified from the reference lists of selected papers.

RESULTS

A total of 51 papers related to the use of IR in anesthesia medical education (including both technical and nontechnical skills) and 63 papers related to applications in clinical practice (eg, preprocedure planning, patient education, and pain management) were included. We present evidence supporting the use of IR in the training and clinical practice of modern anesthesiologists.

CONCLUSIONS

IR is useful for a variety of applications in anesthesia medical education and has potential advantages over existing simulation approaches. Similarly, IR has demonstrated potential improvements in patient care across several clinical contexts relevant to practicing anesthesiologists. However, many applications remain in the early stages of development, and robust trials are urgently needed to confirm clinical or educational effectiveness and to assess mechanisms, educational validity, and cost-effectiveness.

The effects of Augmented Reality on operator Situation Awareness and Head-Down Time

A lack of navigator's Situation Awareness (SA) is one of the leading causes of maritime accidents. Visually observing the area surrounding a vessel continues to be a critical aspect and best practice of safe navigation to establish and maintain SA. Augmented Reality (AR) allows the placement of information in a user's field of view, which can encourage navigators to spend more time looking up at their external environment whilst still having access to operational data. However, empirical evidence on the impact of AR on maritime operations is limited. This paper investigates the effects of AR on navigator SA & Head-Down Time (HDT) using a within-group quasi-experimental design. Seventeen licensed navigators and nautical students analysed twelve navigation scenarios: six non-AR (control) and six AR (experimental) scenarios using a maritime training simulator. SA was measured via SAGAT scores for each scenario and the SA-SWORD to compare preferences. Each scenario was video recorded and analysed for participant's total amount of HDT and head-down occurrences in each scenario. Results found that the addition of AR significantly reduced participant HDT (by a factor of 2.67) and head-down occurrences (by 62%) in comparison to navigation scenarios without AR. Furthermore, AR did not significantly improve mean SA. This study contributes to the limited empirical data on the effects of AR on operator performance, demonstrating the potential value of AR for improving SA and facilitating increased head-up time during maritime navigation, which in turn could improve safety at sea.

Attention to Changes on a Head-Worn Display: Two Preclinical Studies with Healthcare Scenarios

OBJECTIVE

In two experiments, we examined how quickly different visual alerts on a head-worn display (HWD) would capture participants' attention to a matrix of patient vital sign values, while multitasking.

BACKGROUND

An HWD could help clinicians monitor multiple patients, regardless of where the clinician is located. We sought effective ways for HWDs to alert multitasking wearers to important events.

METHODS

In two preclinical experiments, university student participants performed a visuomotor tracking task while simultaneously monitoring simulated patient vital signs on an HWD to detect abnormal values. Methods to attract attention to abnormal values included highlighting abnormal vital signs and imposing a white flash over the entire display.

RESULTS

Experiment 1 found that participants detected abnormal values faster with high contrast than low contrast greyscale highlights, even while performing difficult tracking. In Experiment 2, a white flash of the entire screen quickly and reliably captured attention to vital signs, but less so on an HWD than on a conventional screen.

CONCLUSION

Visual alerts on HWDs can direct users' attention to patient transition events (PTEs) even under high visual-perceptual load, but not as quickly as visual alerts on fixed displays. Aspects of the results have since been tested in a healthcare context.

APPLICATION

Potential applications include informing the design of HWD interfaces for monitoring multiple processes and informing future research on capturing attention to HWDs.

Analytic Review of Using Augmented Reality for Situational Awareness

Situational awareness is the perception and understanding of the surrounding environment. Maintaining situational awareness is vital for performance and error prevention in safety critical domains. Prior work has examined applying augmented reality (AR) to the context of improving situational awareness, but has mainly focused on the applicability of using AR rather than on information design. Hence, there is a need to investigate how to design the presentation of information, especially in AR headsets, to increase users' situational awareness. We conducted a Systematic Literature Review to research how information is currently presented in AR, especially in systems that are being utilized for situational awareness. Comparing current presentations of information to existing design recommendations aided in identifying future areas of design. In addition, this survey further discusses opportunities and challenges in applying AR to increasing users' situational awareness.

Use of a head-mounted patient display in a task driven anaesthesia simulator: a randomised trial

INTRODUCTION

Head-mounted displays (HMDs) are becoming increasingly investigated in the realm of healthcare. These devices are worn on the user's head and display information directly to the eye. This allows for near-constant delivery of information, regardless of user position. Increasing advances in technology have allowed for miniaturisation, increasing sophistication, wireless capability and prolonged battery life, all of which allow for more opportunities for these devices to be used in a clinical setting.

METHODS

A prospective, randomised, controlled, parallel-group study was conducted. Subjects were randomised to either an HMD group or a non-HMD group. All subjects then underwent a standardised intraoperative care simulation experience consisting of multiple procedures that required completion within a set time limit. During this period, subjects concurrently monitored the physiological state of a simulated patient. Multiple standardised physiological derangements were displayed to the subjects via either the worn HMD or standard monitors. The primary outcome was the time to recognition of these physiological derangements.

RESULTS

A total of 39 anaesthesia providers were enrolled in this study. There was a significant decrease in the total time it took them to recognise the simulated physiological derangements in the HMD group (difference of 38.2% (95% CI 20.3% to 56.1%); p=0.011) No significant differences in the time that it took to perform the required simulated procedures were observed. Significantly fewer physiological derangements were overlooked by the HMD group than the control group overall (relative risk reduction 0.78 (95% CI 0.31 to 0.94); p=0.003).

CONCLUSIONS

Recent advances in HMD technology may be able to produce a functional adjunctive monitoring device that improves the speed with which anaesthesia providers respond to intraoperative events. This benefit comes without increasing distraction from the task. Further studies in true operative environments are needed to validate this technology.

Head-Mounted Display-Based Augmented Reality for Image-Guided Media Delivery to the Heart: A Preliminary Investigation of Perceptual Accuracy

By aligning virtual augmentations with real objects, optical see-through head-mounted display (OST-HMD)-based augmented reality (AR) can enhance user-task performance. Our goal was to compare the perceptual accuracy of several visualization paradigms involving an adjacent monitor, or the Microsoft HoloLens 2 OST-HMD, in a targeted task, as well as to assess the feasibility of displaying imaging-derived virtual models aligned with the injured porcine heart. With 10 participants, we performed a user study to quantify and compare the accuracy, speed, and subjective workload of each paradigm in the completion of a point-and-trace task that simulated surgical targeting. To demonstrate the clinical potential of our system, we assessed its use for the visualization of magnetic resonance imaging (MRI)-based anatomical models, aligned with the surgically exposed heart in a motion-arrested open-chest porcine model. Using the HoloLens 2 with alignment of the ground truth target and our display calibration method, users were able to achieve submillimeter accuracy (0.98 mm) and required 1.42 min for calibration in the point-and-trace task. In the porcine study, we observed good spatial agreement between the MRI-models and target surgical site. The use of an OST-HMD led to improved perceptual accuracy and task-completion times in a simulated targeting task.

Ergonomics in the anaesthetic workplace: Guideline from the Association of Anaesthetists

Ergonomics in relation to anaesthesia is the scientific study of the interaction between anaesthetists and their workspace environment in order to promote safety, performance and well-being. The foundation for avoiding pain or discomfort at work is to adopt and maintain a good posture, whether sitting or standing. Anaesthetists should aim to keep their posture as natural and neutral as possible. The successful practice of anaesthesia relies on optimisation of ergonomics and lack of attention to detail in this area is associated with impaired performance. The anaesthetic team should wear comfortable clothing, including appropriately-sized personal protective equipment where necessary. Temperature, humidity and light should be adequate at all times. The team should comply with infection prevention and control guidelines and monitoring as recommended by the Association of Anaesthetists. Any equipment or machinery that is mobile should be positioned where it is easy to view or reach without having to change the body or head position significantly when interacting with it. Patients who are supine should, whenever possible, be raised upwards to limit the need to lean towards them. Any item required during a procedure should be positioned on trays or trolleys that are close to the dominant hand. Pregnancy affects the requirements for standing, manually handling, applying force when operating equipment or moving machines and the period over which the individual might have to work without a break. Employers have a duty to make reasonable adjustments to accommodate disability in the workplace. Any member of staff with a physical impairment needs to be accommodated and this includes making provision for a wheelchair user who needs to enter the operating theatre and perform their work.

Augmenting Critical Care Patient Monitoring Using Wearable Technology: Review of Usability and Human Factors

Background

Continuous monitoring of the vital signs of critical care patients is an essential component of critical care medicine. For this task, clinicians use a patient monitor (PM), which conveys patient vital sign data through a screen and an auditory alarm system. Some limitations with PMs have been identified in the literature, such as the need for visual contact with the PM screen, which could result in reduced focus on the patient in specific scenarios, and the amount of noise generated by the PM alarm system. With the advancement of material science and electronic technology, wearable devices have emerged as a potential solution for these problems. This review presents the findings of several studies that focused on the usability and human factors of wearable devices designed for use in critical care patient monitoring.

Objective

The aim of this study is to review the current state of the art in wearable devices intended for use by clinicians to monitor vital signs of critical care patients in hospital settings, with a focus on the usability and human factors of the devices.

Methods

A comprehensive literature search of relevant databases was conducted, and 20 studies were identified and critically reviewed by the authors.

Results

We identified 3 types of wearable devices: tactile, head-mounted, and smartwatch displays. In most cases, these devices were intended for use by anesthesiologists, but nurses and surgeons were also identified as potentially important users of wearable technology in critical care medicine. Although the studies investigating tactile displays revealed their potential to improve clinical monitoring, usability problems related to comfort need to be overcome before they can be considered suitable for use in clinical practice. Only a few studies investigated the usability and human factors of tactile displays by conducting user testing involving critical care professionals. The studies of head-mounted displays (HMDs) revealed that these devices could be useful in critical care medicine, particularly from an ergonomics point of view. By reducing the amount of time the user spends averting their gaze from the patient to a separate screen, HMDs enable clinicians to improve their patient focus and reduce the potential of repetitive strain injury.

Conclusions

Researchers and designers of new wearable devices for use in critical care medicine should strive to achieve not only enhanced performance but also enhanced user experience for their users, especially in terms of comfort and ease of use. These aspects of wearable displays must be extensively tested with the intended end users in a setting that properly reflects the intended context of use before their adoption can be considered in clinical settings.

The Use of Head-Worn Displays for Vital Sign Monitoring in Critical and Acute Care: Systematic Review

Background

Continuous monitoring of patient vital signs may improve patient outcomes. Head-worn displays (HWDs) can provide hands-free access to continuous vital sign information of patients in critical and acute care contexts and thus may reduce instances of unrecognized patient deterioration.

Objective

The purpose of the study is to conduct a systematic review of the literature to evaluate clinical, surrogate, and process outcomes when clinicians use HWDs for continuous patient vital sign monitoring.

Methods

The review was registered with PROSPERO (CRD42019119875) and followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. A literature search was conducted for articles published between January 1995 and June 2020 using the following databases: PubMed, Embase, CINAHL, PsycINFO, and Web of Science. Overall, 2 reviewers independently screened titles and abstracts and then assessed the full text of the articles. Original research articles that evaluated the clinical, surrogate, or process outcomes of head-mounted displays for continuous vital sign monitoring in critical care or acute care contexts were included.

Results

Of the 214 records obtained, 15 (7%) articles met the predefined criteria and were included in this review. Of the 15 studies, 7 (47%) took place in a clinical context, whereas the remainder took place in a simulation environment. In 100% (7/7) of the studies that evaluated gaze behavior, changes were found in gaze direction with HWDs. Change detection improvements were found in 67% (2/3) of the studies evaluating changes in the participants’ ability to detect changes in vital signs. Of the 10 studies assessing the ease of use of the HWD, most participants of 7 (70%) studies reported that the HWD was easy to use. In all 6 studies in which participants were asked if they would consider using the HWD in their practice, most participants responded positively, but they often suggested improvements on the HWD hardware or display design. Of the 7 studies conducted in clinical contexts, none reported any clinical outcomes.

Conclusions

Although there is limited and sometimes conflicting evidence about the benefits of HWDs from certain surrogate and process outcomes, evidence for clinical outcomes is lacking. Recommendations are to employ user-centered design when developing HWDs, perform longitudinal studies, and seek clinical outcomes.

Trial Registration

PROSPERO International Prospective Register of Systematic Reviews CRD42019119875; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=119875

Head-worn displays and job content: A systematic literature review

Despite the emergence of head-worn displays at work around forty years ago, few studies have appeared about their impact on job content. To investigate this, a systematic literature review was conducted on these devices and job content, defined as job demands and controls. In total, 3481 studies were identified using five scientific databases. After applying selection criteria, reference searches, citation tracking and an in-depth reading, 28 studies were selected for review. Remarkably, the findings of these studies showed contrasting results. Both increases and decreases in job demands and controls were identified. We distinguished across studies two opposite approaches for the deployment of these devices, i.e. a supportive and a directive approach.

Smart Glasses for Anesthesia Care: Initial Focus Group Interviews with Specialized Health Care Professionals

PURPOSE

Smart glasses are a kind of wearable technology that gives users sustained, hands-free access to data and can transmit and receive information wirelessly. Earlier studies have suggested that smart glasses have the potential to improve patient safety in anesthesia care. Research regarding health care professionals' views of the potential use of smart glasses in anesthesia care is limited. The purpose of this study was to describe anesthesia health care professionals' views of smart glasses before clinical use.

DESIGN

A qualitative descriptive study.

METHODS

Data were collected from focus group interviews and analyzed using thematic content analysis.

FINDINGS

Three categories of participants' views of smart glasses were created during the analysis: views of integrating smart glasses in clinical setting; views of customized functionality of smart glasses; and views of being a user of smart glasses. One theme, striving for situational control, was identified in the analysis.

CONCLUSIONS

Smart glasses were seen as a tool that can impact and improve access to patient-related information, and aid health care professionals in their struggle to gain situational control during anesthesia care. These are factors related to increased patient safety.

Smart Glasses for Caring Situations in Complex Care Environments: Scoping Review

BACKGROUND

Anesthesia departments and intensive care units represent two advanced, high-tech, and complex care environments. Health care in those environments involves different types of technology to provide safe, high-quality care. Smart glasses have previously been used in different health care settings and have been suggested to assist health care professionals in numerous areas. However, smart glasses in the complex contexts of anesthesia care and intensive care are new and innovative. An overview of existing research related to these contexts is needed before implementing smart glasses into complex care environments.

OBJECTIVE

The aim of this study was to highlight potential benefits and limitations with health care professionals' use of smart glasses in situations occurring in complex care environments.

METHODS

A scoping review with six steps was conducted to fulfill the objective. Database searches were conducted in PubMed and Scopus; original articles about health care professionals' use of smart glasses in complex care environments and/or situations occurring in those environments were included. The searches yielded a total of 20 articles that were included in the review.

RESULTS

Three categories were created during the qualitative content analysis: (1) smart glasses as a versatile tool that offers opportunities and challenges, (2) smart glasses entail positive and negative impacts on health care professionals, and (3) smart glasses' quality of use provides facilities and leaves room for improvement. Smart glasses were found to be both a helpful tool and a hindrance in caring situations that might occur in complex care environments. This review provides an increased understanding about different situations where smart glasses might be used by health care professionals in clinical practice in anesthesia care and intensive care; however, research about smart glasses in clinical complex care environments is limited.

CONCLUSIONS

Thoughtful implementation and improved hardware are needed to meet health care professionals' needs. New technology brings challenges; more research is required to elucidate how smart glasses affect patient safety, health care professionals, and quality of care in complex care environments.

The impact of concurrent linguistic tasks on participants' identification of spearcons

Spearcons (time-compressed speech) may be a viable auditory display for patient monitoring; however, the impact of concurrent linguistic tasks remains unexamined. We tested whether different concurrent linguistic tasks worsen participants' identification of spearcons. Experiment 1 tested non-clinician participants' identification of multiple-patient spearcons representing 2 vital signs of 5 patients while participants performed no concurrent task, reading, or saying linguistic tasks. Experiment 2 tested non-clinician participants' identification of 48 single-patient spearcons while they performed no concurrent task, reading, listening, and saying linguistic tasks. In Experiment 1 the saying task worsened participants' identification of spearcons compared with no concurrent task or reading. In Experiment 2, the saying and listening tasks reduced participants' accuracy at identifying spearcons, but the reading task did not. Listening affected identification accuracy no differently than the saying task did. Concurrent auditory linguistic tasks worsen participants' identification of spearcons, probably due to auditory modality interference in verbal working memory.

Navigation-Linked Heads-Up Display in Intracranial Surgery: Early Experience

BACKGROUND

The use of intraoperative navigation during microscope cases can be limited when attention needs to be divided between the operative field and the navigation screens. Heads-up display (HUD), also referred to as augmented reality, permits visualization of navigation information during surgery workflow.

OBJECTIVE

To detail our initial experience with HUD.

METHODS

We retrospectively reviewed patients who underwent HUD-assisted surgery from April 2016 through April 2017. All lesions were assessed for accuracy and those from the latter half of the study were assessed for utility.

RESULTS

Seventy-nine patients with 84 pathologies were included. Pathologies included aneurysms (14), arteriovenous malformations (6), cavernous malformations (5), intracranial stenosis (3), meningiomas (27), metastasis (4), craniopharygniomas (4), gliomas (4), schwannomas (3), epidermoid/dermoids (3), pituitary adenomas (2) hemangioblastoma (2), choroid plexus papilloma (1), lymphoma (1), osteoblastoma (1), clival chordoma (1), cerebrospinal fluid leak (1), abscess (1), and a cerebellopontine angle Teflon granuloma (1). Fifty-nine lesions were deep and 25 were superficial. Structures identified included the lesion (81), vessels (48), and nerves/brain tissue (31). Accuracy was deemed excellent (71.4%), good (20.2%), or poor (8.3%). Deep lesions were less likely to have excellent accuracy (P = .029). HUD was used during bed/head positioning (50.0%), skin incision (17.3%), craniotomy (23.1%), dural opening (26.9%), corticectomy (13.5%), arachnoid opening (36.5%), and intracranial drilling (13.5%). HUD was deactivated at some point during the surgery in 59.6% of cases. There were no complications related to HUD use.

CONCLUSION

HUD can be safely used for a wide variety of vascular and oncologic intracranial pathologies and can be utilized during multiple stages of surgery.

Transverse chromatic aberration in virtual reality head-mounted displays

We demonstrate a method for measuring the transverse chromatic aberration (TCA) in a virtual reality head-mounted display. The method relies on acquiring images of a digital bar pattern and measuring the displacement of different color bars. This procedure was used to characterize the TCAs in the Oculus Go, Oculus Rift, Samsung Gear, and HTC Vive. The results show noticeable TCAs for the Oculus devices for angles larger than 5° from the center of the field of view. TCA is less noticeable in the Vive in part due to off-axis monochromatic aberrations. Finally, user measurements were conducted, which were in excellent agreement with the laboratory results.

Supporting multiple patient monitoring with head-worn displays and spearcons

In hospitals, clinicians often need to monitor several patients while performing other tasks. However, visual displays that show patients' vital signs are in fixed locations and auditory alarms intended to alert clinicians may be missed. Information such as spearcons (time-compressed speech earcons) that 'travels' with the clinician and is delivered by earpiece and/or head-worn displays (HWDs), might overcome these problems. In this study, non-clinicians monitored five simulated patients in three 10-min scenarios while performing a demanding tracking task. Monitoring accuracy was better for participants using spearcons and a HWD (88.7%) or a HWD alone (86.2%) than for participants using spearcons alone (74.1%). Participants using the spearcons and HWD (37.7%) performed the tracking task no differently from participants using spearcons alone (37.1%) but participants using the HWD alone performed worse overall (33.1%). The combination of both displays may be a suitable solution for monitoring multiple patients.

The Impact of Head-Worn Displays on Strategic Alarm Management and Situation Awareness

OBJECTIVE

To investigate whether head-worn displays (HWDs) help mobile participants make better alarm management decisions and achieve better situation awareness than alarms alone.

BACKGROUND

Patient alarms occur frequently in hospitals but often do not require clinical intervention. Clinicians may become desensitized to alarms and fail to respond to clinically relevant alarms. HWDs could make patient information continuously accessible, support situation awareness, and help clinicians prioritize alarms.

METHOD

Experiment 1 ( n = 76) tested whether nonclinicians monitoring simulated patients benefited from vital sign information continuously displayed on an HWD while they performed a secondary calculation task. Experiment 2 ( n = 13) tested, across three separate experimental sessions, how effectively nursing trainees monitored simulated patients' vital signs under three different display conditions while they assessed a simulated patient.

RESULTS

In Experiment 1, participants who had access to continuous patient information on an HWD responded to clinically important alarms 25.9% faster and were 6.7 times less likely to miss alarms compared to participants who only heard alarms. In Experiment 2, participants using an HWD answered situation awareness questions 18.9% more accurately overall than when they used alarms only. However, the effect was significant in only two of the three experimental sessions.

CONCLUSION

HWDs may help users maintain continuous awareness of multiple remote processes without affecting their performance on ongoing tasks.

APPLICATION

The outcomes may apply to contexts where access to continuous streams of information from remote locations is useful, such as patient monitoring or clinical supervision.

The clinical utility of phase-based respiratory gated PET imaging based on visual feedback with a head-mounted display system

OBJECTIVE

We developed a new respiratory-gated positron emission tomography (PET) imaging method (RGV-PET) that phase-based respiratory gated PET imaging (RG-PET) combine with head-mounted display (HMD)-guided "visual feedback." The purpose of this study was to investigate whether RGV-PET is effective at improving the quantitative measurement of tracer uptake in tumors using the phase-based respiratory gating method.

METHODS

Of the 41 enrolled patients with hepatobiliary or pancreatic cancer, 20 patients underwent RGV-PET and the remaining 21 patients underwent RG-PET. We measured the peak standardized uptake value (SUVpeak) of the primary lesion in each five bins obtained from both RG-PET and RGV-PET. The SUVpeak change rate calculated based on the ungated PET imaging. To evaluate the quantitative variation, the coefficient of variation of the SUVpeak change rate was compared between RG-PET and RGV-PET. In addition, we performed qualitative evaluation using visual score for the incidence of artifacts on four-dimensional-CT.

RESULTS

The coefficient of variation of the average SUVpeak change rate in RGV-PET was 7.01 ± 4.43, which was significantly lower than the values in RG-PET (10.72 ± 5.74, p < 0.05). A significant improvement in the SUVpeak change rate of RGV-PET was obtained in bins 1 and 2 compared to RG-PET ( p < 0.05). The visual score of RGV-PET was significantly lower than RG-PET ( p < 0.05).

CONCLUSION

RGV-PET was effective for respiratory stabilization and improved respiratory gating imaging quality.

ADVANCES IN KNOWLEDGE

The RGV-PET is applicable to various PET/CT respiratory gating imaging and may improve the quantitativeness of PET images.

An Anesthesiologist's Perspective on the History of Basic Airway Management: The "Modern" Era, 1960 to Present

This fourth and last installment of my history of basic airway management discusses the current (i.e., "modern") era of anesthesia and resuscitation, from 1960 to the present. These years were notable for the implementation of intermittent positive pressure ventilation inside and outside the operating room. Basic airway management in cardiopulmonary resuscitation (i.e., expired air ventilation) was de-emphasized, as the "A-B-C" (airway-breathing-circulation) protocol was replaced with the "C-A-B" (circulation-airway-breathing) intervention sequence. Basic airway management in the operating room (i.e., face-mask ventilation) lost its predominant position to advanced airway management, as balanced anesthesia replaced inhalation anesthesia. The one-hand, generic face-mask ventilation technique was inherited from the progressive era. In the new context of providing intermittent positive pressure ventilation, the generic technique generated an underpowered grip with a less effective seal and an unspecified airway maneuver. The significant advancement that had been made in understanding the pathophysiology of upper airway obstruction was thus poorly translated into practice. In contrast to consistent progress in advanced airway management, progress in basic airway techniques and devices stagnated.

Detection of visual stimuli on monocular peripheral head-worn displays

OBJECTIVE

To compare people's ability to detect peripherally presented stimuli on a monocular head-worn display (HWD) versus a conventional screen.

BACKGROUND

Visual attention capture has been systematically investigated, but not with respect to HWDs. How stimulus properties affect attention capture is likely to be different on an HWD when compared to a traditional computer display.

METHOD

Participants performed an ongoing perceptual task and attempted to detect stimuli that were displayed peripherally on either a computer monitor or a monocular HWD.

RESULTS

Participants were less able to detect peripheral stimuli when the stimuli were presented on a HWD than when presented on a computer monitor. Moreover, the disadvantage of the HWD was more pronounced when peripheral stimuli were less distinct and when the stimuli were presented further into the periphery.

CONCLUSION

Presenting stimuli on a monocular head-worn display reduces participants' ability to notice peripheral visual stimuli compared to presentation on a normal computer monitor. This effect increases as stimuli are presented further in the periphery, but can be ameliorated to a degree by using high-contrast stimuli.

APPLICATION

The findings are useful for designers creating visual stimuli intended to capture attention when viewed on a peripherally positioned monocular head-worn display.

A low-cost multimodal head-mounted display system for neuroendoscopic surgery

BACKGROUND

With rapid advances in technology, wearable devices as head-mounted display (HMD) have been adopted for various uses in medical science, ranging from simply aiding in fitness to assisting surgery. We aimed to investigate the feasibility and practicability of a low-cost multimodal HMD system in neuroendoscopic surgery.

METHODS

A multimodal HMD system, mainly consisted of a HMD with two built-in displays, an action camera, and a laptop computer displaying reconstructed medical images, was developed to assist neuroendoscopic surgery. With this intensively integrated system, the neurosurgeon could freely switch between endoscopic image, three-dimensional (3D) reconstructed virtual endoscopy images, and surrounding environment images. Using a leap motion controller, the neurosurgeon could adjust or rotate the 3D virtual endoscopic images at a distance to better understand the positional relation between lesions and normal tissues at will.

RESULTS

A total of 21 consecutive patients with ventricular system diseases underwent neuroendoscopic surgery with the aid of this system. All operations were accomplished successfully, and no system-related complications occurred. The HMD was comfortable to wear and easy to operate. Screen resolution of the HMD was high enough for the neurosurgeon to operate carefully. With the system, the neurosurgeon might get a better comprehension on lesions by freely switching among images of different modalities. The system had a steep learning curve, which meant a quick increment of skill with it. Compared with commercially available surgical assistant instruments, this system was relatively low-cost.

CONCLUSIONS

The multimodal HMD system is feasible, practical, helpful, and relatively cost efficient in neuroendoscopic surgery.

A review of wearable technology in medicine

With rapid advances in technology, wearable devices have evolved and been adopted for various uses, ranging from simple devices used in aiding fitness to more complex devices used in assisting surgery. Wearable technology is broadly divided into head-mounted displays and body sensors. A broad search of the current literature revealed a total of 13 different body sensors and 11 head-mounted display devices. The latter have been reported for use in surgery (n = 7), imaging (n = 3), simulation and education (n = 2) and as navigation tools (n = 1). Body sensors have been used as vital signs monitors (n = 9) and for posture-related devices for posture and fitness (n = 4). Body sensors were found to have excellent functionality in aiding patient posture and rehabilitation while head-mounted displays can provide information to surgeons to while maintaining sterility during operative procedures. There is a potential role for head-mounted wearable technology and body sensors in medicine and patient care. However, there is little scientific evidence available proving that the application of such technologies improves patient satisfaction or care. Further studies need to be conducted prior to a clear conclusion.

Eye Tracking in Anesthesiology

Eye tracking has become a valuable method to study performance and cognition in diverse settings. For the present paper, we reviewed the literature on eye tracking in anesthesiology and identified nine publications. We have summarized the method and results of these publications. Further, we identified and discussed several methodological issues that occur when conducting eye tracking in anesthesiology, such as sample size, large data loss, and differences in study settings. Finally, we suggest future research topics in anesthesiology, which may particularly benefit from eye tracking.

Patient monitoring with Google Glass: a pilot study of a novel monitoring technology

BACKGROUND

Head-mounted devices (HMDs) are of significant interest for applications within medicine, including in anesthesia for patient monitoring. Previous devices trialed in anesthesia for this purpose were often bulky, involved cable tethers, or were otherwise ergonomically infeasible. Google Glass is a modern HMD that is lightweight and solves many of the issues identified with previous HMDs.

AIM

To examine the acceptance of Google Glass as a patient monitoring device in a pediatric anesthesia context at Princess Margaret Hospital for Children, Perth, Australia.

METHODS

We developed a custom-designed software solution for integrating Google Glass into the anesthesia environment, which enabled the device user to continuously view patient monitoring parameters transmitted wirelessly from the anesthesia workstation.

RESULTS

A total of 40 anesthetists were included in the study. Each anesthetist used the device for the duration of a theater list. We found 90% of anesthetists trialing the device agreed that it was comfortable to wear, 86% agreed the device was easy to read, and 82.5% agreed the device was not distracting. In 75% of cases, anesthetists reported unprompted that they were comfortable using the device in theater. Anesthetists reported that they would use the device again in 76% of cases, and indicated that they would recommend the device to a colleague in 58% of cases.

CONCLUSION

Given the pilot nature of this study, we consider these results highly favorable. Anesthetists readily accepted Google Glass in the anesthetic environment, with further enhancements to device software, rather than hardware, now being the barrier to adoption. There are a number of applications for HMDs in pediatric anesthesia.

A novel approach to patient self-monitoring of sonographic examinations using a head-mounted display

OBJECTIVES

Patients' use of a head-mounted display during their sonographic examinations could provide them with information about their diseases in real time and might help improve "patient-centered care." We conducted this prospective study to evaluate the feasibility of a modern head-mounted display for patient self-monitoring of sonographic examinations.

METHODS

In November and December 2013, 58 patients were enrolled. Patients wore a head-mounted display (HMZ-T2; Sony Corporation, Tokyo, Japan) during their sonographic examinations and watched their own images in real time. After the sonographic examinations, the patients completed a questionnaire, in which they evaluated the utility of the head-mounted display, their understanding of their diseases, their satisfaction with using the head-mounted display, and any adverse events. Until November 26, 2013, patients' names were requested on the questionnaire; after that date, the questionnaire was changed to be anonymous.

RESULTS

Of the 58 patients, 56 (97%) elected to participate in this study. The head-mounted display was reported to have good image quality by 42 patients (75%) and good wearability by 39 (70%). Thirty-six patients (64%) reported they had deepened their understanding of their diseases. There were no major complications, and only 2 patients (4%) had mild eye fatigue. There was no significant association between questionnaire results and patient characteristics. None of the questionnaire results changed significantly after the questionnaire was made anonymous.

CONCLUSIONS

The use of a modern head-mounted display by patients during sonographic examinations provided good image quality with acceptable wearability. It could deepen their understanding of their diseases and help develop patient-centered care.

Head-Mounted Display for a Personal Integrated Image Monitoring System: Ureteral Stent Placement

The personal head-mounted display (HMD) has emerged as a novel image monitoring system. We present here the application of a high-definition organic electroluminescent binocular HMD in ureteral stent placement. Our HMD system displayed multiple forms of information such as integrated, sharp, high-contrast images using a four-split screen or a picture-in-picture technique both seamlessly and synchronously. When both the operator and the assistant wore an HMD, they could continuously and simultaneously monitor the cystoscopic and fluoroscopic images in an ergonomically natural position. Furthermore, each participant was able to modulate the displayed images depending on the procedure. In all five cases, both the operator and the assistant successfully used this system with no unfavorable event. No participants experienced any HMD wear-related adverse effects. We therefore believe this HMD system might be potentially beneficial during ureteral stent placement procedures. Furthermore, it is compact, easily introduced and affordable.

A head-mounted display-based personal integrated-image monitoring system for transurethral resection of the prostate

The head-mounted display (HMD) is a new image monitoring system. We developed the Personal Integrated-image Monitoring System (PIM System) using the HMD (HMZ-T2, Sony Corporation, Tokyo, Japan) in combination with video splitters and multiplexers as a surgical guide system for transurethral resection of the prostate (TURP). The imaging information obtained from the cystoscope, the transurethral ultrasonography (TRUS), the video camera attached to the HMD, and the patient's vital signs monitor were split and integrated by the PIM System and a composite image was displayed by the HMD using a four-split screen technique. Wearing the HMD, the lead surgeon and the assistant could simultaneously and continuously monitor the same information displayed by the HMD in an ergonomically efficient posture. Each participant could independently rearrange the images comprising the composite image depending on the engaging step. Two benign prostatic hyperplasia (BPH) patients underwent TURP performed by surgeons guided with this system. In both cases, the TURP procedure was successfully performed, and their postoperative clinical courses had no remarkable unfavorable events. During the procedure, none of the participants experienced any HMD-wear related adverse effects or reported any discomfort.

Surgeons blinded by enhanced navigation: the effect of augmented reality on attention

BACKGROUND

Advanced image-guidance systems allowing presentation of three-dimensional navigational data in real time are being developed enthusiastically for many medical procedures. Other industries, including aviation and the military, have noted that shifting attention toward such compelling assistance has detrimental effects. Using the detection rate of unexpected findings, we assess whether inattentional blindness is significant in a surgical context and evaluate the impact of on-screen navigational cuing with augmented reality.

METHODS

Surgeons and trainees performed an endoscopic navigation exercise on a cadaveric specimen. The subjects were randomized to either a standard endoscopic view (control) or an AR view consisting of an endoscopic video fused with anatomic contours. Two unexpected findings were presented in close proximity to the target point: one critical complication and one foreign body (screw). Task completion time, accuracy, and recognition of findings were recorded.

RESULTS

Detection of the complication was 0/15 in the AR group versus 7/17 in the control group (p = 0.008). Detection of the screw was 1/15 (AR) and 7/17 (control) (p = 0.041). Recognition of either finding was 12/17 for the control group and 1/15 for the AR group (p < 0.001). Accuracy was greater for the AR group than for the control group, with the median distance from the target point measuring respectively 2.10 mm (interquartile range [IQR], 1.29-2.37) and 4.13 (IQR, 3.11-7.39) (p < 0.001).

CONCLUSION

Inattentional blindness was evident in both groups. Although more accurate, the AR group was less likely to identify significant unexpected findings clearly within view. Advanced navigational displays may increase precision, but strategies to mitigate attentional costs need further investigation to allow safe implementation.

University of Queensland vital signs dataset: development of an accessible repository of anesthesia patient monitoring data for research

BACKGROUND

Data recorded from the devices used to monitor a patient's vital signs are often used in the development of displays, alarms, and information systems, but high-resolution, multiple-parameter datasets of anesthesia monitoring data from patients during anesthesia are often difficult to obtain. Existing databases have typically been collected from patients in intensive care units. However, the physical state of intensive care patients is dissimilar to those undergoing surgery, more frequent and marked changes to cardiovascular and respiratory variables are seen in operating room patients, and additional and highly relevant information to anesthesia (e.g., end-tidal agent monitoring, etc.) is omitted from these intensive care databases. We collected a set of high-quality, high-resolution, multiple-parameter monitoring data suitable for anesthesia monitoring research.

METHODS

Vital signs data were recorded from patients undergoing anesthesia at the Royal Adelaide Hospital. Software was developed to capture, time synchronize, and interpolate vital signs data from Philips IntelliVue MP70 and MP30 patient monitors and Datex-Ohmeda Aestiva/5 anesthesia machines into 10 millisecond resolution samples. The recorded data were saved in a variety of accessible file formats.

RESULTS

Monitoring data were recorded from 32 cases (25 general anesthetics, 3 spinal anesthetics, 4 sedations) ranging in duration from 13 minutes to 5 hours (median 105 min). Most cases included data from the electrocardiograph, pulse oximeter, capnograph, noninvasive arterial blood pressure monitor, airway flow, and pressure monitor and, in a few cases, the Y-piece spirometer, electroencephalogram monitor, and arterial blood pressure monitor. Recorded data were processed and saved into 4 file formats: (1) comma-separated values text files with full numerical and waveform data, (2) numerical parameters recorded in comma-separated values files at 1-second intervals, (3) graphical plots of all waveform data in a range of resolutions as Portable Network Graphics image files, and (4) graphical overview plots of numerical data for entire cases as Portable Network Graphics and Scalable Vector Graphics files. The complete dataset is freely available online via doi:102.100.100/6914 and has been listed in the Australian National Data Service Collections Registry.

DISCUSSION

The present dataset provides clinical anesthesia monitoring data from entire surgical cases where patients underwent anesthesia, includes a wide range of vital signs variables that are commonly monitored during surgery, and is published in accessible, user-friendly file formats. The text and image file formats let researchers without engineering or computer science backgrounds easily access the data using standard spreadsheet and image browsing software. In future work, monitoring data should be collected from a wider range and larger number of cases, and software tools are needed to support searching and navigating the database.

A far-view intensive care unit monitoring display enables faster triage

Although nurses perform the majority of the clinical tasks in an intensive care unit, current patient monitors were not designed to support a nurse's workflow. Nurses constantly triage patients, deciding which patient is currently in the most need of care. To make this decision, nurses must observe the patient's vital signs and therapeutic device information from multiple sources. To obtain this information, they often have to enter the patient's room. This study addresses 3 hypotheses. Information provided by far-view monitoring displays (1) reduces the amount of time to determine which patient needs care first, (2) increases the accuracy of assigning priority to the right patient, and (3) reduces nurses mental workload. We developed 2 far-view displays to be read from a distance of 3 to 5 m without entering the patient's room. Both display vital signs, trends, alarms, infusion pump status, and therapy support indicators. To evaluate the displays, nurses were asked to use the displays to decide which of 2 patients required their attention first. They made 60 decisions: 20 with each far-view display and 20 decisions with a standard patient monitor next to an infusion pump. Sixteen nurses (median age of 27.5 years with 2.75 years of experience) participated in the study. Using the 2 far-view displays, nurses more accurately and rapidly identified stable patients and syringe pumps that were nearly empty. Median decision times were 11.3 and 12.4 seconds for the 2 far-view displays and 17.2 seconds for the control display. The 2 far-view displays reduced median decision-making times by 4.8 to 5.9 seconds, increased accuracy in assignment of priority in 2 of 7 patient conditions, and reduced nurses' frustration with the triaging task. In a clinical setting, the proposed far-view display might reduce nurses' mental workload and thereby increase patient safety.