Foad Dabiri

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 sensor networks for health monitoring

We propose a platform for health monitoring using wireless sensor networks. Our platform is a new architecture called CustoMed that will reduce the customization and reconfiguration time for medical systems that use reconfigurable embedded systems. This architecture is a network enabled system that supports various wearable sensors and contains on-board general computing capabilities for executing individually tailored event detection, alerts, and network communication with various medical informatics services. The customization of such system with a large number of med nodes is extremely fast even by non-engineering staff. In this paper, we present the architecture of such device along with experimental analysis that evaluates the performance of such system.

Development of a fully implantable wireless pressure monitoring system

A fully implantable wireless pressure sensor system was developed to monitor bladder pressures in vivo. The system comprises a small commercial pressure die connected via catheter to amplifying electronics, a microcontroller, wireless transmitter, battery, and a personal digital assistant (PDA) or computer to receive the wireless data. The sensor is fully implantable and transmits pressure data once every second with a pressure detection range of 1.5xa0psi gauge and a resolution of 0.02xa0psi. In vitro calibration measurements of the device showed a high degree of linearity and excellent temporal response. The implanted device performed continuously in vivo in several porcine studies lasting over 3xa0days. This system can be adapted for other pressure readings, as well as other vital sign measurements; it represents the first step in developing a ubiquitous sensing platform for telemedicine and remote patient monitoring.

Adaptive and fault tolerant medical vest for life-critical medical monitoring

In recent years, exciting technological advances have been made in development of flexible electronics. These technologies offer the opportunity to weave computation, communication and storage into the fabric of the every clothing that we wear, therefore, creating intelligent fabric. This paper presents a medical vest which has sensors for physiological readings and software-controlled, electrically-actuated trans-dermal drug delivery elements. Furthermore, computational elements are embedded in the vest for collecting data from sensors, processing them and driving actuation elements. Since this vest will be used for medical, life-critical applications, the single most critical requirement of such a vest is an extremely high level of robustness and fault tolerance. Meantime, the key technological constraint for these mobile systems is their power consumption. Our target application for our medical vest is the detection of possibly fatal heart problems, specifically unstable angina pectoris or ischemia. We illustrate the design stages of our medical vest as well as the technical details of both software and network reconfiguration schemes (to enhance the robustness and the performance of our system). We also discuss the details of ischemia detection algorithm employed in our vest. Moreover, we evaluate the robustness of our system with existence of various faults. Finally we measure the performance of our algorithm as well the power consumption of several configurations of our vest.

Theoretical Bound and Practical Analysis of Connected Dominating Set in Ad Hoc and Sensor Networks

Connected dominating setis widely used in wireless ad-hoc and sensor networks as a routing and topology control backbone to improve the performance and increase the lifetime of the network. Most of the distributed algorithms for approximating connected dominating set are based on constructing maximal independent set. The performance of such algorithms highly depends on the relation between the size of the maximum independent set (mis(G)) and the size of the minimum connected dominating set (cds(G)) in the graph G. In this paper, after observing the properties of such subgraphs, we decrease the previous ratio of 3.453 to 3.0 by showing that mis(G) ≤ 3·mcds(G) + 3. Additionally, we prove that this bound is tight and cannot be improved. Finally, we present practical analysis of constructing connected dominating set based on maximal independent set in wireless networks. It is shown that the theoretical bound for unit disk graphis still practically applicable for general wireless networks.

Ubiquitous personal assistive system for neuropathy

The improvement in processor performance through continuous breakthroughs in transistor technology has resulted in the proliferation of lightweight embedded systems. Advances in wireless technology and embedded systems have enabled remote healthcare and telemedicine. Continuous and real-time monitoring can discretely analyze how a patients lifestyle affects his/her physiological conditions and if additional symptoms occur under various stimuli.n Diabetes is one of most difficult challenges facing the health-care industry today. One of the primary afflictions of diabetic patients is peripheral neuropathy (loss of sensation in the foot). As a direct result of this condition, the likelihood of ulcer increases which in many cases leads to to amputation. We have developed a wireless electronic orthotics composed of lightweight embedded systems and non-invasive sensors which can be used by diabetic patients suffering from peripheral neuropathy. Our proposed system monitors feet motion and pressure distribution beneath the feet in real-time and classifies the state of the patient. The proposed system detects the conditions that could potentially cause a foot ulcer. This system enables a continuous feedback mechanism for instance in case of an undesired behavior or condition a preemptive message wirelessly to the patients cell phone/PDA/PC and over the WEB to the patients care-giver. This system can potentially reduce the amputation rates resulting from neuropathy by a huge factor.

Hardware aging-based software metering

Reliable and verifiable hardware, software and content usage metering (HSCM) are of primary importance for wide segments of e-commerce including intellectual property and digital rights management. We have developed the first HSCM technique that employs intrinsic aging properties of components in modern and pending integrated circuits (ICs) to create the first self-enforceable HSCM approach. There are variety of hardware aging techniques that range from electro-migration in wires to slow-down of crystal-based clocks. We focus on transistor aging due to negative bias temperature instability (NBTI) effects where the delay of gates increases proportionally to usage times. We address the problem of how we can measure the amount of time a particular licensed software (LS) is used by designing an aging circuitry and exposing it to the unique inputs associated with each LS. If a particular LS is used longer than specified, it automatically disables itself. Our novel HSCM technique uses a multi-stage optimization problem of computing the delays of gates, their aging degradation factors, and finally LS usage using convex programming. The experimental results show not just viability of the technique but also surprisingly high accuracy in the presence of measurement noise and imperfect aging models. HSCM can be used for many other business and engineering applications such as power minimization, software evaluation, and processor design.

QUANTIFIED DEEP TENDON REFLEX DEVICE, SECOND GENERATION

The deep tendon reflex is a fundamental aspect of neurological examinations. The severity of and degree of recovery from a traumatic brain injury can be assessed by the myotatic stretch reflex. A hyperactive reflex response is correlated with spasticity, which can also be correlated with the degree of damage to the supraspinal input, in essence assessing the severity of traumatic brain injury. The myotatic stretch reflex is clinically evaluated by the National Institute of Neurological Disorders and Stroke (NINDS) reflex scale (0–4); however, this scale lacks temporal data and may also vary in interpretation. The solution is a fully quantified evaluation system of the myotatic stretch reflex, whereby a patellar hammers force input is based on original potential energy and a microelectromechanical system (MEMS) accelerometer quantifies the output. The MEMS accelerometer is attached to a set anchor point near the ankle. The reflex amplitude is based on the maximum acceleration of the reflex response. The quantified data collected from MEMS accelerometers are transmitted by a portable computer (i.e. a Pocket PC). This paper describes a device that quantitatively evaluates the reflex response using accelerometers and that demonstrates precision for reproducibility.

Optimal register sharing for high-level synthesis of SSA form programs

Register sharing for high-level synthesis of programs represented in static single assignment (SSA) form is proven to have a polynomial-time solution. Register sharing is modeled as a graph-coloring problem. Although graph coloring is NP-Complete in the general case, an interference graph constructed for a program in SSA form probably belongs to the class of chordal graphs that have an optimal O(|V|+|E|) time algorithm. Chordal graph coloring reduces the number of registers allocated to the program by as much as 86% and 64.93% on average compared to linear scan register allocation.

A Telehealth Architecture for Networked Embedded Systems: A Case Study in In Vivo Health Monitoring

The improvement in processor performance through continuous breakthroughs in transistor technology has resulted in the proliferation of lightweight embedded systems. Advances in wireless technology and embedded systems have enabled remote healthcare and telemedicine. While medical examinations could previously extract only localized symptoms through snapshots, now continuous monitoring can discretely analyze how a patients lifestyle affects his/her physiological conditions and if additional symptoms occur under various stimuli. We demonstrate how medical applications in particular benefit from a hierarchical networking scheme that will improve the quantity and quality of ubiquitous data collection. Our Telehealth networking infrastructure provides flexibility in terms of functionality and the type of applications that it supports. We specifically present a case study that demonstrates the effectiveness of our networked embedded infrastructure in an in vivo pressure application. Experimental results of the in vivo system demonstrate how it can wirelessly transmit pressure readings measuring from 0 to 1.5 lbf/in2 with an accuracy of 0.02 lbf/in2. The challenges in biocompatible packaging, transducer drift, power management, and in vivo signal transmission are also discussed. This research brings researchers a step closer to continuous, real-time systemic monitoring that will allow one to analyze the dynamic human physiology.