The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Karl F Doerner - One of the best experts on this subject based on the ideXlab platform.
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Ambulance location and relocation problems with time dependent travel times
European Journal of Operational Research, 2010Co-Authors: Verena Schmid, Karl F DoernerAbstract:Emergency service providers are facing the following problem: how and where to locate vehicles in order to cover potential future demand effectively. Ambulances are supposed to be located at designated locations such that in case of an emergency the patients can be reached in a time-efficient manner. A patient is said to be covered by a vehicle if (s)he can be reached by an Ambulance within a predefined time limit. Due to variations in speed and the resulting travel times it is not sufficient to solve the static Ambulance location problem once using fixed average travel times, as the coverage areas themselves change throughout the day. Hence we developed a multi-period version, taking into account time-varying coverage areas, where we allow vehicles to be repositioned in order to maintain a certain coverage standard throughout the planning horizon. We have formulated a mixed integer program for the problem at hand, which tries to optimize coverage at various points in time simultaneously. The problem is solved metaheuristically using variable neighborhood search. We show that it is essential to consider time-dependent variations in travel times and coverage respectively. When ignoring them the resulting objective will be overestimated by more than 24%. By taking into account these variations explicitly the solution on average can be improved by more than 10%.
Sean Ahearne - One of the best experts on this subject based on the ideXlab platform.
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5G World Forum - 5G Network Slicing for Mission-critical use cases
2019 IEEE 2nd 5G World Forum (5GWF), 2019Co-Authors: Mark Roddy, Thuy Truong, Mustafa Al Bado, Paul Walsh, Michael Healy, Sean AhearneAbstract:The demand for prehospital emergency care has increased during the last decades throughout the Western world, in terms of numbers of emergency calls and dispatched Ambulances. This development represents a challenge for both the prehospital emergency systems and the emergency departments at the hospitals [1]. Stroke is the fourth single leading cause of death in the UK and an accurate recognition of stroke by in-Ambulance or emergency medical services (EMS) or prehospital Ambulance paramedics, offers significant potential to reduce delays in presentation and treatment in acute stroke [2]. This paper demonstrates Proof-of-Concept (PoC) approaches for 5G network slicing in mission-critical use cases from the H2020 5G PPP SliceNet project, which is implementing an End-to-End (E2E) cognitive network slicing and slice management framework in virtualised multi-domain, multi-tenant 5G Networks. The paper shows how the PoC's key enablers, such as QoS-aware network slicing, edge computing and hardware acceleration, can assist with a continuous collection, processing and streaming of patient data that could shorten the time to assess and provide optimal clinical treatment pathways for potential stroke patients.
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5G Network Slicing for Mission-critical use cases
2019 IEEE 2nd 5G World Forum (5GWF), 2019Co-Authors: Mark Roddy, Thuy Truong, Mustafa Al Bado, Yanxin Wu, Paul Walsh, Michael Healy, Sean AhearneAbstract:The demand for prehospital emergency care has increased during the last decades throughout the Western world, in terms of numbers of emergency calls and dispatched Ambulances. This development represents a challenge for both the prehospital emergency systems and the emergency departments at the hospitals [1]. Stroke is the fourth single leading cause of death in the UK and an accurate recognition of stroke by in-Ambulance or emergency medical services (EMS) or prehospital Ambulance paramedics, offers significant potential to reduce delays in presentation and treatment in acute stroke [2]. This paper demonstrates Proof-of-Concept (PoC) approaches for 5G network slicing in mission-critical use cases from the H2020 5G PPP SliceNet project, which is implementing an End-to-End (E2E) cognitive network slicing and slice management framework in virtualised multi-domain, multi-tenant 5G Networks. The paper shows how the PoC's key enablers, such as QoS-aware network slicing, edge computing and hardware acceleration, can assist with a continuous collection, processing and streaming of patient data that could shorten the time to assess and provide optimal clinical treatment pathways for potential stroke patients.
Itai Gurvich - One of the best experts on this subject based on the ideXlab platform.
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centralized vs decentralized Ambulance diversion a network perspective
Management Science, 2011Co-Authors: Sarang Deo, Itai GurvichAbstract:One of the most important operational challenges faced by emergency departments (EDs) in the United States is patient overcrowding. In periods of overcrowding, an ED can request the emergency medical services (EMS) agency to divert incoming Ambulances to neighboring hospitals, a phenomenon known as “Ambulance diversion.” The EMS agency may accept this request provided that at least one of the neighboring EDs is not on diversion. From an operations perspective, properly executed Ambulance diversion should result in resource pooling and reduce the overcrowding and delays in a network of EDs. Recent evidence indicates, however, that this potential benefit is not always realized. In this paper, we provide one potential explanation for this discrepancy and suggest potential remedies. Using a queueing game between two EDs that aim to minimize their own waiting time, we find that decentralized decisions regarding diversion explain the lack of pooling benefits. Specifically, we find the existence of a defensive equilibrium, wherein each ED does not accept diverted Ambulances from the other ED. This defensiveness results in a depooling of the network and, subsequently, in delays that are significantly higher than when a social planner coordinates diversion. The social optimum is itself difficult to characterize analytically and has limited practical appeal because it depends on problem parameters such as arrival rates and length of stay. Instead, we identify an alternative solution that does not require the exact knowledge of the parameters and may be used by the EMS agencies to coordinate diversion decisions when defensive diversion is present. We show that this solution is approximately optimal for the social planner's problem. Moreover, it is Pareto improving over the defensive equilibrium whereas the social optimum, in general, might not be. This paper was accepted by Yossi Aviv, operations management.
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centralized vs decentralized Ambulance diversion a network perspective
2011Co-Authors: Sarang Deo, Itai GurvichAbstract:In recent years, growth in the demand for emergency medical services along with decline in the number of hospitals with emergency departments (EDs) has led to overcrowding. In periods of overcrowding, an ED can request the Emergency Medical Services (EMS) agency to divert incoming Ambulances to neighboring hospitals, a phenomenon known as “Ambulance diversion”. The EMS agency will accept this request provided that at least one of the neighboring EDs is not on diversion. From an operations perspective, properly executed Ambulance diversion should result in resource pooling and reduce the overcrowding and delays in a network of EDs. Recent evidence indicates, however, that this potential benefit is not always realized. In this paper, we provide one potential explanation for this discrepancy and suggest potential remedies. Using a queueing game between two EDs that aim to minimize their own waiting time, we find that decentralized decisions regarding diversion explain the lack of pooling benefits. Specifically, we find the existence of a defensive equilibrium, wherein each ED does not accept diverted Ambulances from the other ED. This defensiveness results in a de-pooling of the network and, in turn, in delays that are significantly higher than when a social planner coordinates diversion. The social optimum is, itself, difficult to characterize analytically and has limited practical appeal as it depends on problem parameters such as arrival rates and length of stay. Instead, we identify an alternative solution that is more amenable to implementation and can be used by the EMS agencies to coordinate diversion decisions even without the exact knowledge of these parameters. We show that this solution is approximately optimal for the social planner’s problem. Moreover, it is Pareto improving over the defensive equilibrium whereas the social optimum might not be.
Rob Van Der Mei - One of the best experts on this subject based on the ideXlab platform.
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Real-time Ambulance relocation: Assessing real-time redeployment strategies for Ambulance relocation
Socio-Economic Planning Sciences, 2018Co-Authors: Thije Van Barneveld, Caroline Jagtenberg, Sandjai Bhulai, Rob Van Der MeiAbstract:Providers of Emergency Medical Services (EMS) are typically concerned with keeping response times short. A powerful means to ensure this, is to dynamically redistribute the Ambulances over the region, depending on the current state of the system. In this paper, we provide new insight into how to optimally (re)distribute Ambulances. We study the impact of (1) the frequency of redeployment decision moments, (2) the inclusion of busy Ambulances in the state description of the system, and (3) the performance criterion on the quality of the distribution strategy. In addition, we consider the influence of the EMS crew workload, such as (4) chain relocations and (5) time bounds, on the execution of an Ambulance relocation. To this end, we use trace-driven simulations based on a real dataset from Ambulance providers in the Netherlands. In doing so, we differentiate between rural and urban regions, which typically face different challenges when it comes to EMS. Our results show that: (1) taking the classical 0-1 performance criterion for assessing the fraction of late arrivals only differs slightly from related response time criteria for evaluating the performance as a function of the response time, (2) adding more relocation decision moments is highly beneficial, particularly for rural areas, (3) considering Ambulances involved in dropping off patients available for newly coming incidents reduces relocation times only slightly, and (4) simulation experiments for assessing move-up policies are highly preferable to simple mathematical models.
Kuanhwa Hsiung - One of the best experts on this subject based on the ideXlab platform.
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video recording and time motion analyses of manual versus mechanical cardiopulmonary resuscitation during Ambulance transport
Resuscitation, 2007Co-Authors: Huichih Wang, Wenchu Chiang, Sheyying Chen, Chunlin Chi, Chihwei Yang, Peiching Lin, Yaocheng Wang, Tsungche Tsai, Chienhwa Huang, Kuanhwa HsiungAbstract:Summary Introduction The quality of cardiopulmonary resuscitation (CPR) plays a crucial role in saving lives from out-of-hospital cardiac arrest (OHCA). Previous studies have identified sub-optimal CPR quality in the prehospital settings, but the causes leading to such deficiencies were not fully elucidated. Objective This prospective study was conducted to identify operator- and Ambulance-related factors affecting CPR quality during Ambulance transport; and to assess the effectiveness of mechanical CPR device in such environment. Materials and methods A digital video-recording system was set up in two Ambulances in Taipei City to study CPR practice for adult, non-traumatic OHCAs from January 2005 to March 2006. Enrolled patients received either manual CPR or CPR by a mechanical device (Thumper). Quality of CPR in terms of (1) adequacy of chest compressions, (2) instantaneous compression rates, and (3) unnecessary no-chest compression interval, was assessed by time-motion analysis of the videos. Results A total of 20 Ambulance resuscitations were included. Compared to the manual group ( n =12), the Thumper group ( n =8) had similar no-chest compression interval (33.40% versus 31.63%, P =0.16); significantly lower average chest compression rate (113.3±47.1min −1 versus 52.3±14.2min −1 , P −1 versus 77.2±6.9min −1 , P −1 versus 11.7±3.5min −1 , P P Conclusions Many unnecessary no-chest compression intervals were identified during Ambulance CPR, and most of this was operator, rather than Ambulance related. Though a mechanical device could minimise the no-chest compression intervals after activation, it took considerable time to deploy in a system with short transport time. Human factors remained the most important cause of poor CPR quality. Ways to improve the CPR quality in the Ambulance warrant further study.
