Image guidance system use amongst Canadian otolaryngologists: a nationwide survey.

BACKGROUND: The use of image guidance systems has gained widespread acceptance as an adjunctive tool for endoscopic sinus surgery. However, the accessibility and usage of this technology is variable across hospitals in Canada. STUDY OBJECTIVE: The aim of this study is to investigate the availability, usage, and related issues surrounding the use of image guidance systems in endoscopic sinus surgery across Canadian otolaryngology practice settings. METHODS: An online survey was electronically distributed to practicing otolaryngologists across Canada. The survey contained 27 questions pertaining to the availability, usage, barriers and overall experience of image guidance systems. RESULTS: The survey was electronically sent to a total of 654 Canadian otolaryngologists of which 158 responded (response rate 24.2%). Image guidance was available to 56.3% of respondents. Of the respondents without access to IGS, 85.5% indicated they would use it if it was available. Financial (capital cost) was identified as the most important barrier in obtaining IGS by 76.3% of respondents. CONCLUSION: Over half of Canadian otolaryngologists have access to IGS with over 85% of those without access interested in using it if it was made available. A multitude of different factors contribute to this disparity. We hope that the results of this study will help support Canadian otolaryngologists to access IGS.

Revised recommendations from the CSO-HNS taskforce on performance of tracheotomy during the COVID-19 pandemic - what a difference a year makes.

BACKGROUND: During the early part of the COVID-19 pandemic, the Canadian Society of Otolaryngology - Head & Neck Surgery (CSO-HNS) task force published recommendations on performance of tracheotomy. Since then, our understanding of the virus has evolved with ongoing intensive research efforts. New literature has helped us better understand various aspects including patient outcomes and health care worker (HCW) risks associated with tracheotomy during the COVID-19 pandemic. Accordingly, the task force has re-evaluated and revised some of the previous recommendations. MAIN BODY: Based on recent evidence, a negative reverse transcription polymerase chain reaction (RT-PCR) COVID-19 swab status is no longer the main deciding factor in the timing of tracheotomy. Instead, tracheotomy may be considered as soon as COVID-19 swab positive patients are greater than 20 days beyond initial symptoms and 2 weeks of mechanical ventilation. Furthermore, both open and percutaneous surgical techniques may be considered with both techniques showing similar safety and outcome profiles. Additional recommendations with discussion of current evidence are presented. CONCLUSION: These revised recommendations apply new evidence in optimizing patient and health care system outcomes as well as minimizing risks of COVID-19 transmission during aerosol-generating tracheotomy procedures. As previously noted, additional evidence may lead to further evolution of these and other similar recommendations.

Canadian Rhinology Working Group consensus statement: biologic therapies for chronic rhinosinusitis.

BACKGROUND: Recent evidence suggests that biologic therapy with targeted activity within the Type 2 inflammatory pathway can improve the clinical signs and symptoms of chronic rhinosinusitis with nasal polyposis (CRSwNP). There remains a population in CRSwNP that despite medical therapy and endoscopic sinus surgery have persistent signs and symptoms of disease. Therefore, biologics, monoclonal antibody agents, could be beneficial therapeutic treatments for these patients. There have been eight randomized, double-blind, placebo-controlled trails performed for CRSwNP targeted components of the Type 2 inflammatory pathway, notably interleukin (IL)-4, IL-5 and IL-13, IL-5R, IL-33, and immunoglobulin (Ig)E. However, there are no formal recommendations for the optimal use of biologics in managing Chronic Rhinosinusitis (CRS) within the Canadian health care environment. METHODS: A Delphi Method process was utilized involving three rounds of questionnaires in which the first two were completed individually online and the third was discussed on a virtual platform with all the panelists. 17 fellowship trained rhinologists across Canada evaluated the 28 original statements on a scale of 1-10 and provided comments. A rating within 1-3 indicated disagreement, 8-10 demonstrated agreement and 4-7 represented being neutral towards a statement. All ratings were quantitively reviewed by mean, median, mode, range and standard deviation. Consensus was defined by removing the highest and lowest of the scores and using the "3 point relaxed system". RESULTS: After three rounds, a total of 11 statements achieved consensus. This white paper only contains the final agreed upon statements and clear rationale and support for the statements regarding the use of biologics in patients with CRS. CONCLUSION: This white paper provides guidance to Canadian physicians on the use of biologic therapy for the management of patients with CRS, but the medical and surgical regimen should ultimately be individualized to the patient. As more biologics become available and additional trials are published we will provide updated versions of this white paper every few years.

CSO (Canadian Society of Otolaryngology - Head & Neck Surgery) position paper on return to Otolaryngology - Head & Neck Surgery Clinic Practice during the COVID-19 pandemic in Canada.

The novel Coronavirus (COVID-19) has created a worldwide deadly pandemic that has become a major public health challenge. All semi-urgent and elective medical care has come to a halt to conserve capacity to care for patients during this pandemic. As the numbers of COVID-19 cases decrease across Canada, our healthcare system also began to reopen various facilities and medical offices. The aim for this document is to compile the current evidence and provide expert consensus on the safe return to clinic practice in Otolaryngology - Head & Neck Surgery. These recommendations will also summarize general precaution principles and practical tips for office across Canada to optimize patient and provider safety. Risk assessment and patient selection are crucial to minimizing exposure to COVID-19. Controversial topics such as COVID-19 mode of transmission, duration of exposure, personal protective equipment, and aerosol-generating procedures will be analyzed and discussed. Practical solutions of pre-visit office preparation, front office and examination room set-up, and check out procedures are explored. Specific considerations for audiology, pediatric population, and high risk AGMPs are also addressed. Given that the literature surrounding COVID-19 is rapidly evolving, these guidelines will serve to start our specialty back into practice over the next weeks to months and they may change as we learn more about this disease.

Recommendations from the CSO-HNS taskforce on performance of tracheotomy during the COVID-19 pandemic.

INTRODUCTION: The performance of tracheotomy is a common procedural request by critical care departments to the surgical services of general surgery, thoracic surgery and otolaryngology - head & neck surgery. A Canadian Society of Otolaryngology - Head & Neck Surgery (CSO-HNS) task force was convened with multi-specialty involvement from otolaryngology-head & neck surgery, general surgery, critical care and anesthesiology to develop a set of recommendations for the performance of tracheotomies during the COVID-19 pandemic. MAIN BODY: The tracheotomy procedure is highly aerosol generating and directly exposes the entire surgical team to the viral aerosol plume and secretions, thereby increasing the risk of transmission to healthcare providers. As such, we believe extended endotracheal intubation should be the standard of care for the entire duration of ventilation in the vast majority of patients. Pre-operative COVID-19 testing is highly recommended for any non-emergent procedure. CONCLUSION: The set of recommendations in this document highlight the importance of avoiding tracheotomy procedures in patients who are COVID-19 positive if at all possible. Recommendations for appropriate PPE and environment are made for COVID-19 positive, negative and unknown patients requiring consideration of tracheotomy. The safety of healthcare professionals who care for ill patients and who keep critical infrastructure operating is paramount.

[Joint pain and consumption of analgesics among young elite athletes : Nationwide data from youth basketball]. / Gelenkschmerzen und Analgetikakonsum bei jungen Leistungssportlern : Bundesweite Daten aus dem Jugendbasketball.

BACKGROUND: Joint pain may be an early indicator of biomechanical stress. During adolescence the physical development, including the development of the musculoskeletal system, is still ongoing and joint pain requires special attention, especially among young athletes. OBJECTIVE: Young athletes from the highest national basketball leagues in Germany were questioned about prevalence, location, context and coping strategies concerning joint pain. MATERIAL AND METHODS: Data were derived from the German "Adolescents' and Childrens' Health in Elite Basketball study" (ACHE study). Analyses were based on an online survey of 182 elite basketball players between 13 and 19 years of age from 46 German teams, conducted between April 2016 and June 2016. RESULTS: In the highest German leagues 2 out of 3 players suffered from joint pain at the time of the survey (7-day prevalence 64.6%). Pain in the lower extremities occurred most frequently. The 7­day prevalence for knee and leg pain reached up to 40% and foot pain up to 21%. For 84% of all players, occasional consumption of analgesics was the norm and 40% took them frequently. The consumption of several medicinal substances, especially of cyclooxygenase inhibitors, such as ibuprofen and diclofenac, is widespread among adolescent elite basketball players as 1 out of 7 athletes (13%) used medicinal substances despite being pain-free and 5% used it prophylactically with the purpose of preventing pain. CONCLUSION: From the point of view of pain medicine, it is not only the high prevalence of pain that is remarkable but also the widespread use of analgesics without a prescription and the misguided conception of adolescent competitive athletes that such medications have preventive effects.

Design Strategies for Redox Active Metalloenzymes: Applications in Hydrogen Production.

The last decades have seen an increased interest in finding alternative means to produce renewable fuels in order to satisfy the growing energy demands and to minimize environmental impact. Nature can serve as an inspiration for development of these methodologies, as enzymes are able to carry out a wide variety of redox processes at high efficiency, employing a wide array of earth-abundant transition metals to do so. While it is well recognized that the protein environment plays an important role in tuning the properties of the different metal centers, the structure/function relationships between amino acids and catalytic centers are not well resolved. One specific approach to study the role of proteins in both electron and proton transfer is the biomimetic design of redox active peptides, binding organometallic clusters in well-understood protein environments. Here we discuss different strategies for the design of peptides incorporating redox active FeS clusters, [FeFe]-hydrogenase organometallic mimics, and porphyrin centers into different peptide and protein environments in order to understand natural redox enzymes.

[Role of the poultry red mite (Dermanyssus gallinae) in the transmission of avian influenza A virus]. / Rolle der Roten Vogelmilbe (Dermanyssus gallinae) bei der Übertragung von aviärem Influenza-A-Virus.

OBJECTIVE: The aim of this study was to investigate the role of the poultry red mite (Dermanyssus [D.] gallinae) in the horizontal transmission of avian influenza A virus (AIV) to chickens. This mite is the most common ectoparasite in poultry worldwide, and may play a role in the spread of infectious agents including AIV. Currently, the control of mites is difficult due to frequently developed resistance to many acaricides, their nocturnality and their ability to survive hidden without feeding for months. MATERIALS AND METHODS: D. gallinae were collected in a commercial layer farm and housed in self-made fibreboard boxes. SPF chickens were intravenously infected with AIV strain A/turkey/Ontario/7732/1966 (H5N9). The viraemia in chickens was monitored and at an appropriate time point about 1000 mites were allowed to suck on the AIV infected chickens. Re-isolation of the virus from blood-filled mites was tried daily for 14 days using chicken embryo fibroblast cultures and embryonated chicken eggs. Subsequently, the virus containing mites were placed into boxes that contained naïve SPF chickens to enable virus transmission from mites to chickens. Possible transmission to the chickens was examined using clinical signs, serology, gross lesions, histopathology and immunohistochemistry. RESULTS: Chickens developed a dose-dependent viraemia one day after infection, therefore this day was chosen for the bloodmeal of the mites. AIV was detected in mites after bloodsucking on AIV-infected chickens over a 10-day period. Naïve SPF chickens were infected during bloodsucking of AIV carrying mites. AIV isolates in mites and in chickens were undistinguishable from the original AIV inoculum by RT-PCR. CONCLUSIONS: D. gallinae ingested AIV during bloodmeals on AIV infected chickens and are able to transmit AIV to SPF chickens. Therefore, mites serve as mechanical vector of AIV and may play a major role in the circulation of AIV within a facility or area although the life span of infectious virus in the mite is limited. CLINICAL RELEVANCE: The proven transmission requires more than ever a systematic control of this ectoparasite in order to maintain poultry health and productivity. The demonstrated vector function of this mite is of great significance for poultry flocks all over the world.

Squeeze bottle versus saline spray after endoscopic sinus surgery for chronic rhinosinusitis: a pilot multicentre trial.

BACKGROUND: There is a need for controlled trials to guide the perioperative management of patients undergoing endoscopic sinus surgery (ESS). The authors performed a pilot multicenter trial to compare two types of saline delivery devices in this population. METHODS: Patients were randomized to high volume saline irrigation with a squeeze bottle and low volume saline spray after ESS in patients with chronic rhinosinusitis (CRS). Surgeons were blinded to treatment, and one-month postoperative scores for sinonasal outcomes [Sinonasal Outcome Test-22 (SNOT-22)] scale, nasal and sinus symptom score (NSS), and perioperative sinus endoscopy (POSE) scale were compared with preoperative scores. RESULTS: Nine centers provided data for 86 patients. All three outcomes measures improved significantly for both groups. Saline spray: SNOT-22 48.8 versus. 23.7, treatment effect 25.1 (95% confidence interval [CI], 17.9-32.2), POSE 21.1 versus. 8.4, treatment effect 12.7 (95% CI, 9.2-16.1), and NSS 8.2 versus 5.0, treatment effect 3.1 (95% CI, 1.4-4.9) pre- and postoperatively, respectively (all p < 0.0001). Squeeze bottle: SNOT-22 49.5 versus 23.6, treatment effect 25.9 (95% CI, 20.3-31.6), POSE 18.6 versus 9.2, treatment effect 9.3, (95% CI 6.7-12.0), and NSS 9.0 versus 5.7, treatment effect 3.3 (95% CI, 2.3-4.3) pre- and postoperatively, respectively (all p < 0.0001). Analysis of variance did not identify a difference between the two treatment groups. Subgroup analysis based on preoperative disease severity did not change the nonassociation of saline bottle with outcome measures. Post hoc sample size calculation determined that 176 patients is required to detect an 8.9-point difference in SNOT-22 scores. CONCLUSION: In this pilot multicenter trial examining patients with chronic rhinosinusitis undergoing ESS, both squeeze bottle and saline spray showed significant improvement in SNOT-22, POSE, and NSS scores at one-month postoperatively. Because the study was nonpowered, we cannot rule out a potential difference between the two treatment groups.

[Investigation of the practical use of a vaccination device ("Pullet Vaccinator") for young layers]. / Untersuchungen zum Einsatz des Impfautomaten "Pullet Vaccinator" in der Junghennenaufzucht.

OBJECTIVE: To evaluate the safety of layer vaccination of the vaccination device "Pullet Vaccinator", its publicised increased operational safety and the practicality of the device using serological monitoring of the vaccination success. MATERIALS AND METHODS: In a first trial, two veterinarians experienced in the syringe method vaccinated hens using the syringe and the vaccination device, respectively. After 1 hour, the equipment was switched and both veterinarians continued to vaccinate for a further hour. The second trial proceeded as in the first trial, except with untrained persons. For each of the four vaccination groups (experienced/syringe; experienced/device; untrained/syringe; untrained/device), the number of vaccinated hens was counted and 20 hens were dissected from each group to compare the impact of both inoculation methods on the animals. To monitor vaccination success, blood was collected for serological screening. On the final blood collection day, further hens per group were dissected to evaluate possible long-term injuries. RESULTS: The vaccination device offers greater occupational safety compared to the syringe method. Vaccination injuries to the hens' breast muscles were more pronounced with the syringe application. For experienced persons, the number of vaccinated animals per hour was approximately doubled using the syringe compared to the device. For the untrained, a comparable number of vaccinated animals was recorded for both methods. Serological monitoring did not show any significant differences in antibody response to the vaccination between both methods. CONCLUSION AND CLINICAL RELEVANCE: In certain points, the device proved technically imperfect and should be revised for improved use in the field.

A 2013 updated systematic review & meta-analysis of 36 randomized controlled trials; no apparent effects of non steroidal anti-inflammatory agents on the risk of bleeding after tonsillectomy.

BACKGROUND: Although the literature suggests that non-steroidal anti-inflammatory drugs (NSAIDs) are effective in controlling post-operative pain in the paediatric population, physicians have been reluctant to utilise these medications after tonsillectomy due to concerns of increased bleeding rates. While many surgeons prescribe opioid analgesics postoperatively, these are associated with a number of potential adverse side-effects including nausea, vomiting, constipation, excessive sedation and respiratory compromise. OBJECTIVE OF REVIEW: To compare bleeding rates and severity between recipients of NSAIDs versus placebo or opioid analgesics for tonsillectomy. SEARCH STRATEGY: Two authors independently searched electronic databases including PubMed, OVID, EMBASE and Cochrane Review from inception to July 2012. The keywords used included: Adenotonsillectomy, Tonsillectomy, Analgesia, Bleeding, Perioperative and Postoperative. These were then combined in various combinations with specific NSAIDs. EVALUATION METHOD: A systematic review and meta-analysis of all randomised control trials comparing bleeding rates and severity between NSAIDs versus placebo or opioids post-tonsillectomy. RESULTS: A total of 36 studies met our inclusion criteria including 1747 children and 1446 adults. When all of the studies were combined in a meta-analysis using the most severe outcome, there was no increased risk of bleeding in those using NSAIDs after tonsillectomy. Use of NSAIDs in general [1.30 (0.90-1.88)] or in children [1.06 (0.65-1.74)] was not associated with increased risk of bleeding in general, most severe bleeding, secondary haemorrhage, readmission or need of reoperation due to bleeding. Similarly, there was no increased bleeding risk for specific NSAIDs in adults. In the studies looking at paediatric subjects, the overall odds ratio of bleeding was even lower than in the general population and not significant. This result is based on 18 studies, six of which had zero outcomes in either treatment arm. Similar to the general population analysis, there was no significant difference in any of the subanalyses: bleeds treated with reoperation, readmission or bleeds in children that could be managed conservatively. There were also no significant differences in the subanalyses of individual NSAIDs. Similarly, there was no significant difference in rates of bleeding in the subanalysis of studies that gave NSAIDs multiple times, for instance, both before and after surgery. CONCLUSIONS: These results suggest that NSAIDs can be considered as a safe method of analgesia among children undergoing tonsillectomy.

Salmonella detection in poultry samples. Comparison of two commercial real-time PCR systems with culture methods for the detection of Salmonella spp. in environmental and fecal samples of poultry.

STUDY: The efficiency of two commercial PCR methods based on real-time technology, the foodproof® Salmonella detection system and the BAX® PCR Assay Salmonella system was compared to standardized culture methods (EN ISO 6579:2002 - Annex D) for the detection of Salmonella spp. in poultry samples. MATERIAL AND METHODS: Four sample matrices (feed, dust, boot swabs, feces) obtained directly from poultry flocks, as well as artificially spiked samples of the same matrices, were used. All samples were tested for Salmonella spp. using culture methods first as the gold standard. In addition samples spiked with Salmonella Enteridis were tested to evaluate the sensitivity of both PCR methods. Furthermore all methods were evaluated in an annual ring-trial of the National Salmonella Reference Laboratory of Germany. RESULTS: Salmonella detection in the matrices feed, dust and boot swabs were comparable in both PCR systems whereas the results from feces differed markedly. The quality, especially the freshness, of the fecal samples had an influence on the sensitivity of the real-time PCR and the results of the culture methods. In fresh fecal samples an initial spiking level of 100cfu/25g Salmonella Enteritidis was detected. Two-days-dried fecal samples allowed the detection of 14cfu/25g. Both real- time PCR protocols appear to be suitable for the detection of Salmonella spp. in all four matrices. The foodproof® system detected eight samples more to be positive compared to the BAX® system, but had a potential false positive result in one case. In 7-days-dried samples none of the methods was able to detect Salmonella likely through letal cell damage. CLINICAL RELEVANCE: In general the advantage of PCR analyses over the culture method is the reduction of working time from 4-5 days to only 2 days. However, especially for the analysis of fecal samples official validation should be conducted according to the requirement of EN ISO6579:2002 - Annex D.

Short communication: Evidence for methylglyoxal-mediated browning of Parmesan cheese during low temperature storage.

Brown pigmentation can occasionally form in Parmesan cheese during the ripening process, creating an unappealing appearance and associated off-flavors. The browning reactions proceed at refrigerated temperatures and in the relative absence of reducing sugar, contrary to typical Maillard browning. Residual sugars, lipid oxidation products, byproducts of fermentation, and (or) enzymes may react with primary amines in cheese to form brown pigmentation and concomitantly generate volatile compounds unique to each of these reactions. Determining the volatile profiles provides a means of understanding the potential substrates involved and causative reaction pathways. This work is divided into 2 segments. The first portion characterized the pigmentation and the browning index of Parmesan cheeses with and without extensive browning. The second phase examined the volatile character of the cheeses using gas chromatography-mass spectrometry. Various pyrazines, such as 2,3,5-trimethylpyrazine and 3,5-diethyl-2-methylpyrazine, were found in the brown cheeses but were not present in the white samples. The formation of pyrazines is proposed to result from the spontaneous condensation of aminoacetone. Aminoacetone can be formed by the Strecker degradation of amino acids with methylglyoxal, the latter a byproduct of sugar fermentation. Evidence is provided to support a browning pathway mediated by the production of methylglyoxal in Parmesan cheese.

[Air conducted ocular VEMP: II. First clinical investigations]. / Luftleitungsinduzierte oculäre VEMP: II. Erste klinische Untersuchungen.

BACKGROUND: Vestibular-evoked myogenic potentials (VEMP) are widely used to assess vestibular function. Air conducted (AC) cervical VEMP (cVEMP) reflect sacculus and inferior vestibular nerve function. Ocular VEMP (oVEMP) however has been hardly examined up to now. In recent studies it has been assumed that AC oVEMP probably reflects superior vestibular nerve function. The aim of this pilot study was to evaluate clinical application of the AC oVEMP. MATERIAL AND METHODS: AC oVEMP were recorded in patients with peripheral vestibular disorders (n=21). In addition thermal irritation and head impulse test were performed and AC cVEMP were recorded. For intense AC-sound stimulation tone bursts (500 Hz) with 100 dB nHL were used. RESULTS: In peripheral vestibular disorders AC oVEMP and AC cVEMP could be classified into: • type 1 (inferior vestibular neuritis) with loss of AC oVEMP but normal AC cVEMP, • type 2, probable type of superior vestibular neuritis, showing present AC cVEMP but loss of AC oVEMP, • type 3, probable complete vestibular neuritis, without AC oVEMP and AC cVEMP. CONCLUSIONS: AC oVEMP may be used as an appropriate test for clinical investigation in patients with vestibular disorders. AC oVEMP is an additional, essential test for assessing otolith function beside AC cVEMP. Further vestibular test are necessary for precise clinical interpretation.

[Air conducted ocular VEMP: I. Determination of a method and application in normal patients]. / Luftleitungsinduzierte oculäre VEMP I. Methodik und Untersuchungen bei normalen Probanden.

BACKGROUND: Air conducted (AC) cervical vestibular evoked myogenic potentials (AC cVEMP) and air conducted ocular VEMP (AC oVEMP) may be used for measurement of otolith function. However AC oVEMP are few examined till now. The aim of this pilot study was to apply a method for use of AC oVEMP in clinical practice. PATIENTS AND METHODS: AC oVEMP were recorded in healthy voluntary people (n=20) using intense AC-sound stimulation (500 Hz tone bursts, 100 dB nHL). Thermal irrigation and AC cVEMP were normal as including criteria. Values were evaluated statistically. RESULTS: AC oVEMP were recorded in all healthy patients. Mean and standard deviation for the first negative peak was 11.35±1.00 ms and for the first negative peak 16.30±1.10 ms. The mean amplitudes were 7.70±4.50 µV. The stability of n10 and p15 component was the same. CONCLUSIONS: AC oVEMP can be easy and fast obtained. N10 and p15 latencies may used as parameter for clinical interpretation. Amplitude fluctuations are relatively large. Results can be used in further clinical investigation of AC oVEMP.

[The use of artificial neural networks in evaluation of posturographic data]. / Die Anwendung künstlicher neuronaler Netze bei der Auswertung posturografischer Messungen.

BACKGROUND: Posturography methods have been applied in clinical neurootology to evaluate the equilibrium function of patients. Methods of statistical analysis play an important role for improving data processing and to support the interpretation of the results. In contrast to conventional statistics, artificial neural networks are model-free and non-parametric. The aim of the presented study was to investigate how accurately these methods are able to discriminate between healthy and equilibrium-disturbed subjects. PATIENTS AND METHODS: 51 healthy volunteers participated in this study. 2 static posturography measurements were recorded before and 40 min after alcohol intake (0.4‰-0.6‰). Recorded signals were processed by 4 different methods in order to estimate power spectral densities (0 Hz-25 Hz). 11 different methods of artificial neural networks were investigated. The ability of artificial neural networks for classification was evaluated in patients with an acute unilateral vestibular loss. RESULTS: It turned out that estimating power spectral densities by means of autoregressive modelling and subsequent classification by Support-Vector Machine or by Learning Vector Quantization Networks are most accurate. Validation analysis yielded mean classification errors for the test set of 4.2 ± 2.2%. CONCLUSIONS: Analysis of neurootological data by artificial neural networks proved to be a sensitive recognition method of even small changes of the postural system.

Evaluation of PERCLOS based current fatigue monitoring technologies.

In an overnight driving simulation study three commercially available devices of fatigue monitoring technologies (FMT) were applied to test their accuracy. 16 volunteers performed driving tasks during eight sessions (40 min each) separated by 15 minutes breaks. The main output variable of FMT devices, which is the percentage of eye closure (PERCLOS), the driving performance (standard deviation of lateral position in lane, SDL), the electroencephalogram (EEG) and electrooculogram (EOG) were recorded during driving. In addition, the subjective self-rated Karolinska sleepiness scale (KSS) was assessed every 2 min. As expected, Pearson product-moment correlation coefficient (PMCC) yielded significant linear dependence between KSS and PERCLOS as well as between SDL and PERCLOS. However, if PMCC was estimated within smaller data segments (3 min) as well as without averaging across subjects then strongly decreased correlation coefficients resulted. To further validate PERCLOS at higher temporal resolution its ability to discriminate between mild and strong fatigue was investigated and compared to the results of the same analysis for EEG/EOG. Spectral-domain features of both types of signals were classified using Support-Vector Machines (SVM). Results suggest that EEG/EOG indicate driver fatigue much better than PERCLOS. Therefore, current FMT devices perform acceptably if temporal resolution is low (> 20 min). But, even under laboratory conditions large errors have to be expected if fatigue is estimated on an individual level and with high temporal resolution.

Monitoring of drowsiness and microsleep.

An overview is presented of different studies on monitoring and detection of drowsiness and microsleep (MS) during driving simulation.