Helmuth F. Orthner

Wireless local area network in a prehospital environment

BackgroundWireless local area networks (WLANs) are considered the next generation of clinical data network. They open the possibility for capturing clinical data in a prehospital setting (e.g., a patients home) using various devices, such as personal digital assistants, laptops, digital electrocardiogram (EKG) machines, and even cellular phones, and transmitting the captured data to a physician or hospital. The transmission rate is crucial to the applicability of the technology in the prehospital setting.MethodsWe created two separate WLANs to simulate a virtual local are network environment such as in a patients home or an emergency room (ER). The effects of different methods of data transmission, number of clients, and roaming among different access points on the file transfer rate were determined.ResultsThe present results suggest that it is feasible to transfer small files such as patient demographics and EKG data from the patients home to the ER at a reasonable speed. Encryption, user control, and access control were implemented and results discussed.ConclusionsImplementing a WLAN in a centrally managed and multiple-layer-controlled access control server is the key to ensuring its security and accessibility. Future studies should focus on product capacity, speed, compatibility, interoperability, and security management.

Personalized online information search and visualization

BackgroundThe rapid growth of online publications such as the Medline and other sources raises the questions how to get the relevant information efficiently. It is important, for a bench scientist, e.g., to monitor related publications constantly. It is also important, for a clinician, e.g., to access the patient records anywhere and anytime. Although time-consuming, this kind of searching procedure is usually similar and simple. Likely, it involves a search engine and a visualization interface. Different words or combination reflects different research topics. The objective of this study is to automate this tedious procedure by recording those words/terms in a database and online sources, and use the information for an automated search and retrieval. The retrieved information will be available anytime and anywhere through a secure web server.ResultsWe developed such a database that stored searching terms, journals and et al., and implement a piece of software for searching the medical subject heading-indexed sources such as the Medline and other online sources automatically. The returned information were stored locally, as is, on a server and visible through a Web-based interface. The search was performed daily or otherwise scheduled and the users logon to the website anytime without typing any words. The system has potentials to retrieve similarly from non-medical subject heading-indexed literature or a privileged information source such as a clinical information system. The issues such as security, presentation and visualization of the retrieved information were thus addressed. One of the presentation issues such as wireless access was also experimented. A user survey showed that the personalized online searches saved time and increased and relevancy. Handheld devices could also be used to access the stored information but less satisfactory.ConclusionThe Web-searching software or similar system has potential to be an efficient tool for both bench scientists and clinicians for their daily information needs.

Turning Access into a web-enabled secure information system for clinical trials.

Background Organizations that have limited resources need to conduct clinical studies in a cost-effective, but secure way. Clinical data residing in various individual databases need to be easily accessed and secured. Although widely available, digital certification, encryption, and secure web server, have not been implemented as widely, partly due to a lack of understanding of needs and concerns over issues such as cost and difficulty in implementation. Purpose The objective of this study was to test the possibility of centralizing various databases and to demonstrate ways of offering an alternative to a large-scale comprehensive and costly commercial product, especially for simple phase I and II trials, with reasonable convenience and security. Methods We report a working procedure to transform and develop a standalone AccessTM database into a secure Web-based secure information system. Results For data collection and reporting purposes, we centralized several individual databases; developed, and tested a web-based secure server using self-issued digital certificates. Limitations The system lacks audit trails. The cost of development and maintenance may hinder its wide application. Conclusions The clinical trial databases scattered in various departments of an institution could be centralized into a web-enabled secure information system. The limitations such as the lack of a calendar and audit trail can be partially addressed with additional programming. The centralized Web system may provide an alternative to a comprehensive clinical trial management system.

Optimizing Wireless Communication using Adaptive Packet Sizing and Turbo Codes

Unlike wired networks, wireless networks have very dynamic channel properties and the data communication suffers from interference, multi-path fading and noise. Since wireless devices are mobile, factors such as energy consumption, effective coverage area and most of all reliability and quality of service are of key importance. The 802.11a/b/g wireless protocols employ static link layer control and transmit packets/frames with pre-determined sizes. This paper focuses on benefits derived from combining adaptive packet/frame sizing with forward error correcting (FEC) turbo codes. Protecting the data frames on the channel, using FEC enhances efficiency of dynamic packet sizing and is shown to increase energy efficiency and communication range. Adaptive packet sizing software from SmartPackets Inc. and turbo code simulations are used to discover parameters that are common to both and affect communication efficiency. A multi-fold improvement in throughput is found when these technologies are used simultaneously