Abstract 9873: Comparing Base Locations for Drone-Delivered Defibrillators

Introduction: Drone-delivered defibrillators may improve response for out-of-hospital cardiac arrest (OHCA). Prior studies have assumed that drones may be stationed at any police, fire, or paramedic station; however, cross-service implementation may not be logistically feasible. We sought to compare estimated response times by drone base location type. Methods: We included OHCAs (Jan. 2014 to Dec. 2020) in southern Vancouver Island, British Columbia, Canada where OHCA response includes fire and paramedic services. We created four models with candidate drone base locations at: police stations, fire stations, paramedic stations, and on a grid with 1 km sides as an optimistic model. We used mathematical optimization to select 1-5 drone bases for each model. Assuming a drone system had been in place during the study period and accounting for drone availability, we estimated 9-1-1 call-to-defibrillator intervals (measured to either drone, paramedic, or fire arrival) and calculated the proportion of OHCAs where a drone would arrive prior to fire and paramedic for each model. Median response times were compared to historical response using one-sided sign tests. Results: We included 1,610 OHCAs with a median historical response time of 6.4 mins (IQR 5.0-8.6). We identified 21 police stations, 59 fire stations, 21 paramedic stations, and 7,008 grid locations in the study area. Median 9-1-1 call-to-defibrillator intervals ranged from 4.3-5.3 mins for police, 4.3-5.3 mins for fire, 4.5-5.4 mins for paramedic, and 4.2-5.4 mins for grid locations (all P<0.001). Drones arrived prior to fire and paramedics in 36.6-65.4% of cases for police, 38.1-66.2% for fire, 37.3-63.2% for paramedic, and 35.7-66.8% for grid locations. Conclusion: Locating drone bases at different types of emergency service stations significantly decreases 9-1-1 call-to-defibrillator intervals, while resulting in similar response intervals to those achieved using optimistic grid-optimal locations.

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Out of Hospital Cardiac Arrest Management by First Responders: Retrospective Review of a Fire Fighter First Responder Program

Australasian Journal of Paramedicine ◽

10.33151/ajp.11.5.59 ◽

2014 ◽

Vol 11 (5) ◽

Cited By ~ 1

Author(s):

Christian Winship ◽

Malcolm Boyle ◽

Brett Williams

Keyword(s):

Cardiac Arrest ◽

Response Times ◽

Significant Rise ◽

First Responder ◽

Median Response ◽

Fire Fighters ◽

Shockable Rhythm ◽

Medical Response ◽

Bystander Cpr ◽

Hospital Cardiac Arrest

IntroductionOver 9,500 people die annually in Australia from sudden cardiac arrest, with strong evidence suggesting early high quality CPR and early counter shock being paramount for improving survival from cardiac arrest. It has also been shown that first responder programs have been able to reduce response times and increase survival rates for out-of-hospital cardiac arrest. The objective of this study was to examine data from the first seven years of an Australian out-of-hospital cardiac arrest first responder program where fire fighters provided basic life support.MethodsThis study was a retrospective cohort study of all cardiac arrests attended by the Metropolitan Fire and Emergency Services Board (MFESB) as part of the Emergency Medical Response program over a seven-year period in Melbourne, Victoria, Australia.ResultsThe MFESB attended 4,450 cardiac arrests. The majority of patients presented in asystole 669 (63.7%) with just 243 (23.1%) presenting in a shockable rhythm. The majority of patients in cardiac arrest were males (64.2%) and the mean age of the patients was 67.5 years. The MFESB median response time during the study period was 5.7 minutes (IQR 2.25 minutes), range of 0.15 minutes to 31.7 minutes, which remained stable over the seven years. Patients spent a median time of 4.6 minutes (0.02 seconds to 36.5 minutes) in the care of fire fighters prior to the arrival of EMS. The rhythm on handover to paramedics was asystole in 787 (75.1%) cases with no shockable rhythms. One in three (31.3%) patients received bystander CPR, with a significant rise in the rate of bystander CPR occurring over the last two years.ConclusionThis study demonstrated acceptable response times to cardiac arrests and a low bystander CPR rate prior to arrival of the MFESB. The incidence of a shockable rhythm on arrival of the MFESB was low with the main rhythm being asystole. The main rhythm on handover to paramedics was asystole with non-shockable rhythms. Further research is required to determine the effect on patient outcomes.

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Abstract 148: A Machine Learning-based Dispatch Rule for Drone-delivered Defibrillators

Circulation ◽

10.1161/circ.142.suppl_4.148 ◽

2020 ◽

Vol 142 (Suppl_4) ◽

Author(s):

Jamal Chu ◽

K.H. Benjamin Leung ◽

Sheldon Cheskes ◽

Paul Snobelen ◽

Gordon Nevils ◽

...

Keyword(s):

Machine Learning ◽

Response Time ◽

Response Times ◽

Time Of Day ◽

Sign Test ◽

Type I ◽

Similar Response ◽

Median Response ◽

Optimal Dispatch ◽

Median Response Time

Introduction: Drone-delivered defibrillators may reduce response time for out-of-hospital cardiac arrest (OHCA). However, an optimal dispatch rule is not yet known. Methods: We identified all suspected OHCAs in Peel Region, Ontario, Canada from Jan. 2014 to Dec. 2019. We trained a neural network model to predict emergency medical services (EMS) response times using OHCA location, distance from responding ambulance, day of week and time of day. Instead of least-squares loss, our model optimized a loss function that penalized weighted errors in the dispatch decision (type I/II error). Assuming drones were deployed from three bases in the region, we calculated drone response time to each suspected OHCA using real drone specifications. Our dispatch rule dispatched a drone when its calculated response time was shorter than the predicted EMS response time. Response time was calculated as the minimum of the drone and EMS response times. The performance of our dispatch rule was compared on out-of-sample OHCAs using 5-fold cross validation to the baseline cases of (1) no drones, and (2) drone dispatch to every suspected OHCA. Statistical analysis on the median response times was performed using a right-tailed sign test. Results: We identified 4774 suspected OHCAs with a median historical EMS response time of 6.0 minutes. Using our dispatch rule, median response time was significantly shorter at 3.9 minutes (P<0.001). Drones were dispatched to 3803 cases (79.7%) and of those, drone response was faster than EMS in 3076 cases (80.9%). When the drone was not dispatched, it would have been slower than EMS in 856 cases (88.1%). Sending a drone to every suspected OHCA resulted in an identical median response time of 3.9 minutes (P<0.001), with drones arriving before EMS in 3191 cases (66.8%). Conclusion: A machine learning-based dispatch rule can achieve similar response times as a policy that dispatches a drone to all suspected OHCAs, while dispatching drones less frequently.

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Comprehensive Effects of Short-Term Rental Platforms Across Hotel Types in U.S. and International Destinations

Cornell Hospitality Quarterly ◽

10.1177/19389655211033527 ◽

2021 ◽

pp. 193896552110335

Author(s):

John W. O’Neill ◽

Jihwan Yeon

Keyword(s):

Service Providers ◽

Comprehensive Analysis ◽

Competitive Market ◽

Substitution Effects ◽

Short Term ◽

Hotel Performance ◽

The World ◽

Different Types ◽

Location Type ◽

The Impact

In recent years, short-term rental platforms in the lodging sector, including Airbnb, VRBO, and HomeAway, have received extensive attention and emerged as potentially alternative suppliers of services traditionally provided by established commercial accommodation providers, that is, hotels. Short-term rentals have dramatically increased the available supply of rooms for visitors to multiple international destinations, potentially siphoning demand away from hotels to short-term rental businesses. In a competitive market, an increase in supply with constant demand would negatively influence incumbent service providers. In this article, we examine the substitution effects of short-term rental supply on hotel performance in different cities around the world. Specifically, we comprehensively investigate the substitution effects of short-term rental supply on hotel performance based on hotel class, location type, and region. Furthermore, we segment the short-term rental supply based on its types of accommodations, that is, shared rooms, private rooms, and entire homes, and both examine and quantify the differential effects of these types of short-term rentals on different types of hotels. This study offers a comprehensive analysis regarding the impact of multiple short-term rental platforms on hotel performance and offers both conceptual and practical insights regarding the nature and extent of the effects that were identified.

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The Impact of Mental States on Semi-autonomous Driving Takeover Performance: A Systematic Review

Proceedings of the Human Factors and Ergonomics Society Annual Meeting ◽

10.1177/1071181320641328 ◽

2020 ◽

Vol 64 (1) ◽

pp. 1372-1376

Author(s):

Gaojian Huang ◽

Christine Petersen ◽

Brandon J. Pitts

Keyword(s):

Systematic Review ◽

Autonomous Vehicles ◽

Response Times ◽

Autonomous Driving ◽

Mental States ◽

Manual Control ◽

Monitoring Systems ◽

Wide Range ◽

Different Types ◽

The Impact

Semi-autonomous vehicles still require drivers to occasionally resume manual control. However, drivers of these vehicles may have different mental states. For example, drivers may be engaged in non-driving related tasks or may exhibit mind wandering behavior. Also, monitoring monotonous driving environments can result in passive fatigue. Given the potential for different types of mental states to negatively affect takeover performance, it will be critical to highlight how mental states affect semi-autonomous takeover. A systematic review was conducted to synthesize the literature on mental states (such as distraction, fatigue, emotion) and takeover performance. This review focuses specifically on five fatigue studies. Overall, studies were too few to observe consistent findings, but some suggest that response times to takeover alerts and post-takeover performance may be affected by fatigue. Ultimately, this review may help researchers improve and develop real-time mental states monitoring systems for a wide range of application domains.

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Experiment on People’s Selection of Route Landmarks from Different Types of Geospatial Pictures

Abstracts of the ICA ◽

10.5194/ica-abs-1-172-2019 ◽

2019 ◽

Vol 1 ◽

pp. 1-2

Author(s):

Pyry Kettunen

Keyword(s):

Training Trial ◽

Response Times ◽

Route Planning ◽

Spatial Knowledge ◽

Selection Task ◽

Different Types ◽

Landmark Selection ◽

Vantage Points ◽

Visual Realism ◽

Selection Of

Abstract. Different types of geospatial pictures, such as maps and aerial imagery, have varying potential to provide spatial knowledge for the viewers. Our earlier review has assessed different common types of geopictures with regard to their support for acquiring different types of spatial knowledge (Kettunen et al., 2012). The assessment was based on previous literature about geopicture experiments as well as analytical itemization of the information available on the pictures as a function of picture characteristics, namely vantage point, number of visible vertical features, and visual realism. In addition to the actual assessment, the review concluded that there is an important shortage of empirical evaluations on spatial knowledge acquisition from geopictures, which lag we are addressing with the experiment described here.The aim of the experiment is to find out what kind of geospatial features, or landmarks (see Presson and Montello, 1988; Richter and Winter, 2014), people read from geopictures, does reading differ between pictures, and how does it differ. For the experimental task, we chose a common map activity of planning navigation for walking through an urban route. The stimuli are five different types of common geopictures with both aerial vertical and aerial oblique vantage points as well as with both abstract and photorealistic levels of visual realism (Figure 1). Five routes are to be planned in different areas of city of Helsinki so that a different geopicture type is shown for each route. The pictures are shown as corridors surrounding the shortest walking route.The participants have been recruited from expert and non-expert social media groups and e-mail lists, being called to be over 18 years old. The background questionnaire has asked about their age, gender, possible visual disorders, and frequency of use for each type of map in the experiment.The experimental design for measuring the effect of geopicture type was built randomized and between-participants so that each participant completes series of five pictures, each of different type, in randomized order, and from different geographical areas. Two rounds of five pictures are shown: first, to measure the actual selection of landmarks, and second, to investigate the level of recall of the selected landmarks later. The procedure of the experiment is the following (Figure 2): 1) Introduction, 2) Consent to participate, 3) Training trial of the landmark selection task (1 picture), 4) Testing trials of the landmark selection task (5 pictures), 5) Training trial of the selection recall task (1 picture), 6) Testing trials of the landmark selection task (5 pictures), 7) Background questionnaire, and 8) Thanks and feedback. The Start and End points of the routes are drawn on the pictures (Figure 1) and the participants are asked to plan the shortest route between the points along roads and paths, to point 3–7 features along the route in navigation route for being able to navigate the route, and to enter common names for the features after pointing each feature. Response times, pointed coordinates, and feature names are recorded in order to analyze the participants’ answers.The presentation at the ICC2019 conference will introduce preliminary results of the conducted experiment, reflect them on the previous studies on maps and routing and discuss their implications on the design of map contents from the viewpoint of route planning. The results will build empirical foundation about differences in reading of geospatial picture types, and for selecting appropriate features to be drawn on maps.

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Abstract 344: The Association Between ALS Response Interval and Out-of Hospital Cardiac Arrest Outcomes

Circulation ◽

10.1161/circ.138.suppl_2.344 ◽

2018 ◽

Vol 138 (Suppl_2) ◽

Author(s):

Brian Grunau ◽

Takahisa Kawano ◽

John Tallon ◽

Frank Scheuermeyer ◽

Joshua Reynolds ◽

...

Keyword(s):

Cardiac Arrest ◽

Life Support ◽

Secondary Analysis ◽

Advanced Life Support ◽

Median Response ◽

Neurological Outcomes ◽

Spline Curves ◽

Response Interval ◽

Optimal Deployment ◽

Hospital Cardiac Arrest

Objective: There is conflicting data in studies investigating the effectiveness of advanced life support (ALS) for out-of-hospital cardiac arrest (OHCA). Within a tiered BLS-ALS system, we sought to determine if the ALS response interval was associated with patient outcomes. Methods: This secondary analysis examined prospectively identified consecutive non-traumatic adult OHCAs from 2006-2016 in British Columbia. We excluded EMS-witnessed arrests and those not treated by ALS. The primary and secondary outcomes were survival and favorable neurological outcomes (mRS ≤3) at hospital discharge. Using logistic regression we estimated the association of ALS response interval (9-1-1 call to ALS arrival) and outcomes, adjusting for treatment year, response interval of the first EMS unit, and other baseline characteristics. We drew spline curves to illustrate this relationship. Results: Of 12,722 included cases, survival was 12%. The median response interval for the first EMS unit was 6.4 minutes (IQR 5.2 - 8.3) and for ALS was 11.8 minutes (IQR 8.7 - 16.5).The adjusted odds of survival and favourable neurological outcome for each additional minute in ALS response interval were 0.98 (95 % CI 0.96-0.99) and 0.98, (95% CI 0.97-0.99) respectively. The spline curve demonstrated an initial decline in survival probability that moderated at approximately 11 minutes. Conclusion: Among ALS-treated subjects within our tiered EMS system, earlier ALS arrival was associated with improved survival and favorable neurological outcomes. The greatest yield of ALS care may be prior to 11 minutes. This may help inform the optimal deployment configuration of prehospital providers.

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Abstract 29: A Neighborhood Local Volunteer Response Network Improves Response Time for Cardiac Arrest

Circulation ◽

10.1161/circ.138.suppl_2.29 ◽

2018 ◽

Vol 138 (Suppl_2) ◽

Author(s):

Karl B Kern ◽

Carter Newton ◽

Charles " Wunder ◽

Thomas P Colberg ◽

Marvin J Slepian

Keyword(s):

Cardiac Arrest ◽

Response Times ◽

Retirement Community ◽

Time Of Arrival ◽

Time Saving ◽

Response Network ◽

Community Boundaries ◽

The Mean ◽

Mean Time ◽

Hospital Cardiac Arrest

Background: Minutes are crucial in the treatment of out-of-hospital cardiac arrest (CA). Immediate chest compressions and early defibrillation are keys to good outcomes. Local neighborhood volunteer (vol) response programs may decrease delays to early CPR and AED use. We hypothesized that a coordinated effort of alerting trained neighborhood vols simultaneously with 911 activation of professional EMS providers would provide earlier CPR and defibrillation in such communities. Methods: We developed a program of simultaneously alerting CPR and AED trained neighborhood vols and the local EMS system for cardiac arrest events in a retirement community in Southern Arizona, encompassing approximately 17,300 homes and 21,500 residents. EMS services are provided by 5 stations within the community boundaries. Within a single housing development neighborhood, 9 vols and the closest EMS station were involved in 3 days of mock CA notifications (total of 12 different alerts at various times during daytime hours were sent). This provided a total of 120 response opportunities, 12 for EMS and 108 for vols. The distance to the mock event and the time from alert to arrival were recorded and compared. Results: In the selected 55+ neighborhood, the two groups differed significantly in both distance to the mock cardiac arrest event and in response times. The volunteers average 0.33±0.19 miles from the mock CA incidences while the closest EMS station was 3.3 miles from the tested neighborhood (p<0.0001). Response times (time from call to arrival) were also different. The earliest Vol arrived at 1min 30sec±48sec*, 2 Vols & AED at 1min 38 sec±53sec*, all arriving Vols at 3min 23 sec*, and EMS at 7min 20 sec±1min 13sec (*p<0.0001 vs EMS). Conclusion: When the neighborhood volunteers in this testing period were geographically closer to the mock CA event, they arrived significantly sooner to the scene than did the EMS service. The mean time of arrival for at least 2 vols with an AED was 5 min 42 sec faster than the professional rescuers. The implications for such a time saving could be as much as a 240% increase (25% to 85%) in survival for those with shockable rhythms.

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Time-intensity profiles of cutaneous pain in normal and hyperalgesic skin: a comparison with C-fiber nociceptor activities in monkey and human

Journal of Neurophysiology ◽

10.1152/jn.1984.51.6.1434 ◽

1984 ◽

Vol 51 (6) ◽

pp. 1434-1450 ◽

Cited By ~ 52

Author(s):

R. H. LaMotte ◽

H. E. Torebjork ◽

C. J. Robinson ◽

J. G. Thalhammer

Keyword(s):

Normal Skin ◽

Similar Response ◽

Response Latencies ◽

Median Response ◽

Hairy Skin ◽

Afferent Fibers ◽

C Fiber ◽

Before And After ◽

Pain Ratings ◽

Temporal Profiles

Contributions of evoked discharge in nociceptors with C-fibers to the temporal profiles of magnitude judgments of pain by humans were determined for heat stimulations of the skin before and after the development of hyperalgesia (increased sensitivity to pain) produced by a mild heat injury. Human subjects continuously rated the magnitude of pain evoked by short-duration heat stimuli of 39-51 degrees C delivered to the hairy skin of the arm or leg (calf or foot) before and after the development of hyperalgesia produced by a conditioning stimulus (CS) of either 50 degrees C for 100 s or 48 degrees C for 360 s. During heat stimulations of the leg in humans, magnitude judgments of pain were obtained simultaneously with recordings of evoked discharges in single C-fiber mechanoheat (CMH) nociceptive afferent fibers. Seven fibers were studied before and after the CS. In other experiments, magnitude ratings of pain evoked by heat stimulations of the arm were compared with heat-evoked discharges in 21 CMH nociceptive afferent fibers innervating the hairy skin of the wrist or hand in anesthetized monkeys. From CMH responses obtained in each species, median response latencies were calculated as well as poststimulus time (PST) histograms--the latter plotting mean frequency of discharge versus time during each stimulus. In these analyses, the times of action potentials in CMHs were calculated as they would occur at entry to the lumbar or cervical spinal cord in humans, taking into account the temporal dispersion that should occur because of differing conduction velocities. These results were then compared with response latencies for pain and the temporal profiles of pain ratings made by individual subjects. Comparisons were made for data obtained before the CS (normal skin) and those obtained 10 min after the CS in heat-sensitized (hyperalgesic) skin. For normal skin, PST histograms of mean frequencies of discharge were similar for CMHs with similar heat thresholds (41-43 degrees) in the anesthetized monkey and the awake human. Despite minor discrepancies, there were similarities in the changes in these histograms for monkey and human CMHs following heat sensitization after the CS. It was concluded that CMHs in monkeys and humans have similar response magnitudes and temporal profiles of response to heat. The major differences in the temporal profiles of CMH responses and human pain ratings were the latencies at which CMH responses and pain ratings began, reached maximum, and ended.(ABSTRACT TRUNCATED AT 400 WORDS)

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Response times of ambulances to calls from Midwife Obstetric Units of the Peninsula Maternal and Neonatal Service (PMNS) in Cape Town

Curationis ◽

10.4102/curationis.v32i1.886 ◽

2009 ◽

Vol 32 (1) ◽

Cited By ~ 1

Author(s):

J.K. Marcus ◽

S.E. Clow

Keyword(s):

Response Times ◽

Cape Town ◽

Time Of Arrival ◽

Delayed Response ◽

Western Cape ◽

Negative Consequences ◽

Median Response ◽

Levels Of Care ◽

Wide Range ◽

National Norms

Response times of ambulances to calls from Midwife Obstetric Units, although varied, are perceived as slow. Delays in transporting women experiencing complications during or after their pregnancies to higher levels of care may have negative consequences such as fetal, neonatal or maternal morbidity or death. An exploratory descriptive study was undertaken to investigate the response times of ambulances of the Western Cape Emergency Medical Services to calls from midwife obstetric units (MOUs) in the Peninsula Maternal and Neonatal Services (PMNS) in Cape Town. Response times were calculated from data collected in specific MOUs using a specifically developed instrument. Recorded data included time of call placed requesting transfer, diagnosis or reason for transfer, priority of call and the time of arrival of ambulance to the requesting facility. Mean, median and range of response times, in minutes, to various MOUs and priorities of calls were calculated. These were then compared using the Kruskal-Wallis test. A comparison was then made between the recorded and analysed response times to national norms and recommendations for ambulance response times and maternal transfer response times respectively.A wide range of response times was noted for the whole sample. Median response times across all priorities of calls and to all MOUs in sample fell short of national norms and recommendations. No statistical differences were noted between various priorities of calls and MOUs.The perception of delayed response times of ambulances to MOUs in the PMNS was confirmed in this pilot study.

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Intelligent Interactive Visual Exploration of Temporal Associations among Multiple Time-oriented Patient Records

Methods of Information in Medicine ◽

10.3414/me9227 ◽

2009 ◽

Vol 48 (03) ◽

pp. 254-262 ◽

Cited By ~ 22

Author(s):

Y. Shahar ◽

M. Taieb-Maimon ◽

D. Klimov

Keyword(s):

Response Times ◽

Visual Exploration ◽

Interactive System ◽

Temporal Association ◽

Multiple Time ◽

Similar Response ◽

Patient Records ◽

Knowledge Based ◽

Significant Difference ◽

Similar Accuracy

Summary Objectives: To design, implement and evaluate the functionality and usability of a methodology and a tool for interactive exploration of time and value associations among multiple-patient longitudinal data and among meaningful concepts derivable from these data. Methods: We developed a new, user-driven, interactive knowledge-based visualization technique, called Temporal Association Charts (TACs). TACs support the investigation of temporal and statistical associations within multiple patient records among both con cepts and the temporal abstractions derived from them. The TAC methodology was implemented as part of an interactive system, called VISITORS, which supports intelligent visualization and exploration of longitudinal patient data. The TAC module was evaluated for functionality and usability by a group of ten users, five clinicians and five medical informaticians. Users were asked to answer ten questions using the VISITORS system, five of which required the use of TACs. Results: Both types of users were able to answer the questions in reasonably short periods of time (a mean of 2.5 ± 0.27 minutes) and with high accuracy (95.3 ± 4.5 on a 0–100 scale), without a significant difference between the two groups. All five questions requiring the use of TACs were answered with similar response times and accuracy levels. Similar accuracy scores were achieved for questions requiring the use of TACs and for questions requiring the use only of general exploration operators. However, response times when using TACs were slightly longer. Conclusions: TACs are functional and usable. Their use results in a uniform performance level, regardless of the type of clinical question or user group involved.

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