Tia Gao

Vital Signs Monitoring and Patient Tracking Over a Wireless Network

Patients at a disaster scene can greatly benefit from technologies that continuously monitor their vital status and track their locations until they are admitted to the hospital. We have designed and developed a real-time patient monitoring system that integrates vital signs sensors, location sensors, ad-hoc networking, electronic patient records, and Web portal technology to allow remote monitoring of patient status. This system shall facilitate communication between providers at the disaster scene, medical professionals at local hospitals, and specialists available for consultation from distant facilities

The Advanced Health and Disaster Aid Network: A Light-Weight Wireless Medical System for Triage

Advances in semiconductor technology have resulted in the creation of miniature medical embedded systems that can wirelessly monitor the vital signs of patients. These lightweight medical systems can aid providers in large disasters who become overwhelmed with the large number of patients, limited resources, and insufficient information. In a mass casualty incident, small embedded medical systems facilitate patient care, resource allocation, and real-time communication in the advanced health and disaster aid network (AID-N). We present the design of electronic triage tags on lightweight, embedded systems with limited memory and computational power. These electronic triage tags use noninvasive, biomedical sensors (pulse oximeter, electrocardiogram, and blood pressure cuff) to continuously monitor the vital signs of a patient and deliver pertinent information to first responders. This electronic triage system facilitates the seamless collection and dissemination of data from the incident site to key members of the distributed emergency response community. The real-time collection of data through a mesh network in a mass casualty drill was shown to approximately triple the number of times patients that were triaged compared with the traditional paper triage system.

Wireless Medical Sensor Networks in Emergency Response: Implementation and Pilot Results

This project demonstrates the feasibility of using cost- effective, flexible, and scalable sensor networks to address critical bottlenecks of the emergency response process. For years, emergency medical service providers conducted patient care by manually measuring vital signs, documenting assessments on paper, and communicating over handheld radios. When disasters occurred, the large numbers of casualties quickly and easily overwhelmed the responders. Collaboration with EMS and hospitals in the Baltimore Washington Metropolitan region prompted us to develop miTag (medical information tag), a cost- effective wireless sensor platform that automatically track patients throughout each step of the disaster response process, from disaster scenes, to ambulances, to hospitals. The miTag is a highly extensible platform that supports a variety of sensor add-ons - GPS, pulse oximetry, blood pressure, temperature, ECG - and relays data over a self-organizing wireless mesh network Scalability is the distinguishing characteristic of miTag: its wireless network scales across a wide range of network densities, from sparse hospital network deployments to very densely populated mass casualty sites. The miTag system is out-of-the-box operational and includes the following key technologies: 1) cost-effective sensor hardware, 2) self-organizing wireless network and 3) scalable server software that analyzes sensor data and delivers real-time updates to handheld devices and web portals. The system has evolved through multiple iterations of development and pilot deployments to become an effective patient monitoring solution. A pilot conducted with the Department of Homeland Security indicates miTags can increase the patient care capacity of responders in the field A pilot at Washington Hospital showed miTags are capable of reliably transmitting data inside radio-interference-rich critical care settings.

Empirical study of a medical sensor application in an urban emergency department

User needs and technology availability drive the introduction of wireless sensing applications in clinical environments. While these applications have the potential to improve efficiency and quality of care, very little is known about their performance during day-to-day use at the hospital. In this work, we use data from a deployment of a 802.15.4-based wireless sensor network at the Emergency Room of the Johns Hopkins hospital to answer these questions. Specifically, over a period of ten days we deployed a system of wireless vital signs monitors that measure the heart rate and blood oxygen levels of Emergency Room patients. During this time we collected statistics about the networks RF links, the performance of its tree routing protocol, and its end-to-end reliability. We find that the hospital environment we tested has considerably higher radio noise levels across multiple frequency channels and more bursty links compared to other indoor environments. Nonetheless, the routing protocol we use finds high quality links and the end-to-end packet reception ratio is above 99.9%. Taken as a whole, these preliminary results suggest that despite the challenges that clinical environments pose, wireless medical sensing applications can perform well in these conditions.

A Next Generation Electronic Triage to Aid Mass Casualty Emergency Medical Response

For years, emergency medical response communities have relied upon paper triage tags, clipboards of notes, and voice communications to share information during medical emergencies. This workflow, however, has proven labor intensive, time consuming, and prone to human error. In collaboration with three EMS groups in the Washington, DC Metropolitan area, we have developed a next generation triage system to improve the effectiveness of emergency response. This system includes: 1) electronic triage tags, 2) wearable vital sign sensors, 3) base stations laptops to monitor and manage patients, 4) pervasive tracking software to locate patients at all stages of the disaster response process, and 5) PDAs to support documentation and communication. Our system has evolved through three iterations of rapiddevelopment, field-studies, usability reviews, and focusgroup interview. This paper summarizes engineering considerations for technologies that must operate under constraints of medical emergencies. It is our hope that the lessons reported in this paper will help technologists in developing future emergency response systems.

Wireless Sensing Systems in Clinical Environments: Improving the Efficiency of the Patient Monitoring Process

Multiple studies suggest that the level of patient care may decline in the future because of a larger aging population and medical staff shortages. Wireless sensing systems that automate some of the patient monitoring tasks can potentially improve the efficiency of patient workflows, but their efficacy in clinical settings is an open question. This article examines the potential of wireless sensor network (WSN) technologies to improve the efficiency of the patient-monitoring process in clinical environments. MEDiSN, a WSN designed to continuously monitor the vital signs of ambulatory patients, is designed. The usefulness of MEDiSN is validated with test bed experiments and results from a pilot study performed at the Emergency Department, Johns Hopkins Hospital. Promising results indicate that MEDiSN can tolerate high degrees of human mobility, is well received by patients and staff members, and performs well in real clinical environments.

Participatory user centered design techniques for a large scale ad-hoc health information system

During mass casualty incidents, an enormous amount of data, including the vital signs of the patients, the location of the patients, and the location of the first responders must be gathered and communicated efficiently. The Advanced Health and Disaster Aid Network (AID-N) used participatory design methods to develop an electronic triage system that changed how emergency personnel interacted, collected, and processed data at mass casualty incidents. Through a collaboration between computer scientists, biomedical engineers, usability analysts, paramedics, and medical doctors, AID-N constructed scalable algorithms to monitor a large numbers of patients, an intuitive interface to support overwhelmed responders, and an ad-hoc mesh network that maintained connectivity to patients in ad-hoc, chaotic settings. This paper describes an iterative approach to user-centered design that allows for the collection of a massive amount of data and presents this data in a clear and understandable format to the user.

A Cross-Functional Service-Oriented Architecture to Support Real-Time Information Exchange in Emergency Medical Response

Real-time information communication presents a persistent challenge to the emergency response community. During a medical emergency, various first response disciplines including Emergency Medical Service (EMS), Fire, and Police, and multiple health service facilities including hospitals, auxiliary care centers and public health departments using disparate information technology systems must coordinate their efforts by sharing real-time information. This paper describes a service-oriented architecture (SOA) that uses shared data models of emergency incidents to support the exchange of data between heterogeneous systems. This architecture is employed in the Advanced Health and Disaster Aid Network (AID-N) system, a testbed investigating information technologies to improve interoperation among multiple emergency response organizations in the Washington DC Metropolitan region. This architecture allows us to enable real-time data communication between three deployed systems: 1) a pre-hospital patient care reporting software system used on all ambulances in Arlington County, Virginia) a syndromic surveillance system used by public health departments in the Washington area (ESSENCE), and 3) a hazardous material reference software system (WISER) developed by the National Library Medicine. Additionally, we have extended our system to communicate with three new data sources: 1) wireless automated vital sign sensors worn by patients, 2) web portals for admitting hospitals, and 3) PDAs used by first responders at emergency scenes to input data (SIRP).

Integration of Triage and Biomedical Devices for Continuous, Real-Time, Automated Patient Monitoring

We have developed a patient triage and monitoring system to facilitate effectiveness patient care during emergency medical situations. This system includes: 1) electronic triage tags, 2) location sensors, 3) vital sign sensors, and 4) robust ad-hoc mesh networking software. This paper summarizes our development of continuous, automated, real-time biomedical sensors and software for use by emergency responders during chaotic pre-hospital settings.