No description available.

Up to 80% of serious medical errors occur due to miscommunication from one provider to another (The Joint Commission, 2012). In order to ensure ongoing safe patient care, it is imperative that anesthesia providers communicate effectively and consistently when transferring patient responsibility to other providers, especially to post-anesthesia care unit (PACU) nurses. Multiple patient transfers occur each day and patients are commonly transferred between multiple providers during the same hospital stay. These opportunities are extremely vulnerable to communication errors. Structured patient handoff checklists or tools increase the consistency of information transferred from anesthesia providers to other providers. The Joint Commission recommended in 2012 that all anesthesia providers utilize a standardized patient handoff checklist to increase and improve the quality of data transferred from anesthesia provider to the PACU nurse. Certified Registered Nurse Anesthetists (CRNA) at a local surgical unit provide the bulk of patient handoffs in this postoperative unit, and currently, there is no mandated use of a standardized handoff checklist. As a result, the CRNAs provide a verbal patient handoff that is unscripted. Verbal patient handoffs differ among providers due to individual provider preference. Without using a standardized handoff checklist, there is a risk of increasing communication errors which increase medical errors and negative patient outcomes. Salzwedel (et al., 2013), in a study when utilizing a handoff checklist, concluded that critical patient data conveyed during patient handoffs increased by 32.4% to 48.7% (Salzwedel et al., 2013). Tscholl et al. (2015) and McElroy et al. (2015) through surveys, determined that data transferred between anesthesia providers was more structured. Handoff checklists increased PACU nurse satisfaction regarding the overall handoff experience (McElroy et al., 2015). No studies, to date, were found that understand the perceptions and thoughts of CRNAs regarding the utilization of patient handoff checklists or tools in clinical practice. This Doctor of Nursing Practice (DNP) project assesses the perceptions and thoughts of utilizing standardized handoff checklists among CRNAs. The hope of this study is to better understand CRNA perceptions in order to identify potential barriers or knowledge gaps regarding the benefit of utilizing a standardized patient handoff checklists. Data from this project may be used to structure future quality improvement projects aimed at decreasing communication errors and improve patient outcomes. The results of this project show the majority of CRNAs (89.5%) surveyed for this project were already familiar with handoff checklists. However, only 26.3% of those same participants agreed they currently use a standardized patient handoff checklist. Of the surveyed participants, only 36.8% were interested in utilizing a standardized patient handoff tool even though nearly 50% agreed that using a handoff checklist would increase the consistency of information transferred from anesthesia provider to nurses. This correlates with the 73.7% of participants who already believe they currently transfer pertinent patient information successfully without utilizing a standardized handoff checklist or tool. Despite studies reporting improved patient outcomes, decreased medical errors, and the Joint Commission’s recommendations to use standardized handoff checklists or tools, the majority of anesthesia providers at this facility do not choose to use handoff checklists. By surveying anesthesia providers' thoughts and perceptions, the researcher attempted to answer why anesthesia providers are not utilizing handoff checklists in their daily routines.

No description available.

Recently, wireless access has become an essential part of modern society. Consequently, the demand for new wireless applications and services, as well as the number of wireless users, are gradually increasing. Given that this amount of expansion is eventually controlled by the available radio frequency spectrum, government regulatory agencies have recently adopted a strict approach to the licensing of limited amounts of spectrum to different entities (e.g., public safety, military, service providers, unlicensed devices, and TV). All of them possess exclusive transmissions to their assigned frequency channels. A new study on spectrum efficiency revealed big geographic and temporal variations in spectrum utilisation, ranging from 15-85% in the bands below 3GHz. These variations were less at frequencies above this figure. Recently, the Cognitive Radio (CR) has risen as an encouraging piece of technology to improve spectrum efficiency and to solve the problem of spectrum scarcity. This is because CR allows the secondary (unlicensed) users to occupy unused licensed spectrum bands temporarily, given that the interference of the primary (licensed) users is prohibited or minimised. In this thesis, various spectrum handoff management schemes have been proposed in order to improve the performance evaluation for CR networks. The proposed spectrum handoff schemes use the Opportunistic Spectrum Access (OSA) concept to utilise available spectrum bands. The handoff Secondary Users (SUs) have a higher priority to occupy available spectrum channels in the licensed and unlicensed spectrum bands without interfering with the legacy spectrum owner, i.e. primary users (PUs). However, existing spectrum handoff management schemes in CR networks do not provide high transmission opportunities for handoff secondary users to utilise the available radio spectrum resources. The first part of this thesis addresses the issue of spectrum handoff management in a licensed spectrum band environment. In this case, both reactive and proactive spectrum handoff schemes are proposed. Queuing theory or/and simulation experiments have been used to evaluate the performance of the proposed schemes and compare them with other existing schemes. Handoff delay has mainly been used to investigate the impact of successive handoff operations on the performance of the proposed CR networks. Implemented models have shown an improvement in the adopted performance measures. According to the achieved results, the improvement of the proposed, prioritised handoff schemes in some cases is approximately 75% when compared with existing schemes. On the other hand, the second part of this research proposed a prioritised spectrum handoff scheme in a heterogeneous spectrum environment, which is composed of a pool of licensed and unlicensed spectrum channels. In general, the availability of substantial numbers of the licensed spectrum channels is the key benefit of using this type of radio spectrum channel. Whereas, accessing with equal rights for all types of users is the main advantage of using unlicensed spectrum channels. In this respect, no transmission interruptions occur once a user obtains a channel. In addition, the proposed schemes use only the unlicensed spectrum channels as their backup channels. This enables the user to resume interrupted transmission in the case of the spectrum handoff operation (mainly; due to the appearance of the primary users), and thus facilitates a SUs communication. The proposed principle is investigated using a retrial queuing theory as well as extensive simulation experiments, and is compared with another non-prioritised scheme which do not give any preference to handoff SUs over new SUs. The results indicate that the proposed model has improved on current average handoff delay. This thesis contributes to knowledge by further enhancing the efficient utilisation of available radio spectrum resources and therefore subsequently provides an improvement in the spectrum capacity for wireless cognitive radio networks.

Recently, wireless access has become an essential part of modern society. Consequently, the demand for new wireless applications and services, as well as the number of wireless users, are gradually increasing. Given that this amount of expansion is eventually controlled by the available radio frequency spectrum, government regulatory agencies have recently adopted a strict approach to the licensing of limited amounts of spectrum to different entities (e.g., public safety, military, service providers, unlicensed devices, and TV). All of them possess exclusive transmissions to their assigned frequency channels. A new study on spectrum efficiency revealed big geographic and temporal variations in spectrum utilisation, ranging from 15-85% in the bands below 3GHz. These variations were less at frequencies above this figure. Recently, the Cognitive Radio (CR) has risen as an encouraging piece of technology to improve spectrum efficiency and to solve the problem of spectrum scarcity. This is because CR allows the secondary (unlicensed) users to occupy unused licensed spectrum bands temporarily, given that the interference of the primary (licensed) users is prohibited or minimised. In this thesis, various spectrum handoff management schemes have been proposed in order to improve the performance evaluation for CR networks. The proposed spectrum handoff schemes use the Opportunistic Spectrum Access (OSA) concept to utilise available spectrum bands. The handoff Secondary Users (SUs) have a higher priority to occupy available spectrum channels in the licensed and unlicensed spectrum bands without interfering with the legacy spectrum owner, i.e. primary users (PUs). However, existing spectrum handoff management schemes in CR networks do not provide high transmission opportunities for handoff secondary users to utilise the available radio spectrum resources. The first part of this thesis addresses the issue of spectrum handoff management in a licensed spectrum band environment. In this case, both reactive and proactive spectrum handoff schemes are proposed. Queuing theory or/and simulation experiments have been used to evaluate the performance of the proposed schemes and compare them with other existing schemes. Handoff delay has mainly been used to investigate the impact of successive handoff operations on the performance of the proposed CR networks. Implemented models have shown an improvement in the adopted performance measures. According to the achieved results, the improvement of the proposed, prioritised handoff schemes in some cases is approximately 75% when compared with existing schemes. On the other hand, the second part of this research proposed a prioritised spectrum handoff scheme in a heterogeneous spectrum environment, which is composed of a pool of licensed and unlicensed spectrum channels. In general, the availability of substantial numbers of the licensed spectrum channels is the key benefit of using this type of radio spectrum channel. Whereas, accessing with equal rights for all types of users is the main advantage of using unlicensed spectrum channels. In this respect, no transmission interruptions occur once a user obtains a channel. In addition, the proposed schemes use only the unlicensed spectrum channels as their backup channels. This enables the user to resume interrupted transmission in the case of the spectrum handoff operation (mainly; due to the appearance of the primary users), and thus facilitates a SUs communication. The proposed principle is investigated using a retrial queuing theory as well as extensive simulation experiments, and is compared with another non-prioritised scheme which do not give any preference to handoff SUs over new SUs. The results indicate that the proposed model has improved on current average handoff delay. This thesis contributes to knowledge by further enhancing the efficient utilisation of available radio spectrum resources and therefore subsequently provides an improvement in the spectrum capacity for wireless cognitive radio networks.

<p>VDL mode 4 is a digital data link operating in the VHF band, its mainly use is for the aviation industry.VDL4 can as an example provide with positioning data, speed information of aircrafts or vehicles equipped with a VDL4 transponder. A connection between the groundsystem and the airborne system is called a point to point connection, which can be used for various applications. This data link needs to be transferred between groundstations during flights in order maintain the connection, which is called handoff.</p><p>The handoff process needs to be quick enough to not drop the link and at the same time a low rate of handoffs is desirable. The data link is regarded as a narrow resource and link management data for handoff is considered as overhead.</p><p>This thesis studies how to make the handoff procedure optimal with respect to involved aspects. Previous research of handoff algorithms and models of the VHF-channel are treated. Standardized parameters and procedures in VDL4 and are explored in order to find an optimal solution for the handoff procedure in VDL4.</p><p>The studied topics are analyzed and it is concluded to suggest an algorithm based on an adaptive hysteresis including signal quality and positioning data provided in VDL4. Standardized parameters which could be useful in the handoff procedure are commented, since the VDL4 standards are under development.</p>

Handoff is a synchronous object transfer technique in face-to-face collaborative work and is one of the low-level actions of collaboration that is smooth and natural in physical settings; however, in digital tabletop workspaces, digital handoff is often awkward and difficult to control. We carried out a series of studies to investigate how digital handoff could be improved in tabletop systems. We first observed people doing several real-world tasks around a standard table and found that handoff is as common in the real-world as deposit (an asynchronous tool transfer technique). The study identified several guidelines to support the design of handoff actions in digital tabletop system. We then examined 2D-handoff techniques; by running a pilot study, we compared the traditional handoff technique with the real-world tangible handoff technique, and found that the traditional digital handoff technique was not well suited for transferring objects on the tabletop. By analyzing the handoff mechanism we spot the bottleneck that affected traditional handoff procedures and designed a novel 2D-handoff technique, force-field technique, which alleviated this bottle-neck to solve this problem. Through a user-study we found that the force-field technique was significantly faster than current digital handoff techniques and as good as real-world 2D-handoff techniques. In addition, force-field handoff was most preferred by a majority of participants. We further designed and implemented a 3D-handoff technique that embodies our observations of how handoff occurs in the real-world setting. <p>Finally, we evaluated our design in a simulated digital-tabletop task with the goal of assessing the usefulness of various digital transfer techniques including standard deposit, traditional handoff, force-field and 3D-handoff. The results showed that on the digital tabletop system the percentage of using deposit, 2D-handoff and 3D-handoff techniques is similar with the percentage of using these techniques on the real world physical table. 3D-handoff was the most preferred and the most frequently used technique among the handoff techniques; and the force-field technique is preferred than traditional handoff technique.

VDL mode 4 is a digital data link operating in the VHF band, its mainly use is for the aviation industry.VDL4 can as an example provide with positioning data, speed information of aircrafts or vehicles equipped with a VDL4 transponder. A connection between the groundsystem and the airborne system is called a point to point connection, which can be used for various applications. This data link needs to be transferred between groundstations during flights in order maintain the connection, which is called handoff. The handoff process needs to be quick enough to not drop the link and at the same time a low rate of handoffs is desirable. The data link is regarded as a narrow resource and link management data for handoff is considered as overhead. This thesis studies how to make the handoff procedure optimal with respect to involved aspects. Previous research of handoff algorithms and models of the VHF-channel are treated. Standardized parameters and procedures in VDL4 and are explored in order to find an optimal solution for the handoff procedure in VDL4. The studied topics are analyzed and it is concluded to suggest an algorithm based on an adaptive hysteresis including signal quality and positioning data provided in VDL4. Standardized parameters which could be useful in the handoff procedure are commented, since the VDL4 standards are under development.

Handoff is a synchronous object transfer technique in face-to-face collaborative work and is one of the low-level actions of collaboration that is smooth and natural in physical settings; however, in digital tabletop workspaces, digital handoff is often awkward and difficult to control. We carried out a series of studies to investigate how digital handoff could be improved in tabletop systems. We first observed people doing several real-world tasks around a standard table and found that handoff is as common in the real-world as deposit (an asynchronous tool transfer technique). The study identified several guidelines to support the design of handoff actions in digital tabletop system. We then examined 2D-handoff techniques; by running a pilot study, we compared the traditional handoff technique with the real-world tangible handoff technique, and found that the traditional digital handoff technique was not well suited for transferring objects on the tabletop. By analyzing the handoff mechanism we spot the bottleneck that affected traditional handoff procedures and designed a novel 2D-handoff technique, force-field technique, which alleviated this bottle-neck to solve this problem. Through a user-study we found that the force-field technique was significantly faster than current digital handoff techniques and as good as real-world 2D-handoff techniques. In addition, force-field handoff was most preferred by a majority of participants. We further designed and implemented a 3D-handoff technique that embodies our observations of how handoff occurs in the real-world setting. <p>Finally, we evaluated our design in a simulated digital-tabletop task with the goal of assessing the usefulness of various digital transfer techniques including standard deposit, traditional handoff, force-field and 3D-handoff. The results showed that on the digital tabletop system the percentage of using deposit, 2D-handoff and 3D-handoff techniques is similar with the percentage of using these techniques on the real world physical table. 3D-handoff was the most preferred and the most frequently used technique among the handoff techniques; and the force-field technique is preferred than traditional handoff technique.

The Session Initiation Protocol (SIP) was designed for wire line networks. It was developed to initiate, modify and terminate sessions between two hosts on a network. When the Internet expanded to include wireless hosts, SIP did not scale well for these wireless hosts because of the nature of the wireless channel. Also, there were issues with mobility and real time communication. This thesis proposes improvements to some of the extensions to SIP, for better performance over wireless channels. We investigate the call setup time for various transport mechanisms viz. TCP and UDP, and study the performance of a dynamic Session Timers compared to the current standard of a periodic refresh mechanism, where the frequency of UPDATEs vary with the condition of the wireless channel. We also propose a handoff algorithm that reduces the handover time with decreased packet losses.