AERO: An Objective Peripheral Edema Measurement Device.

Peripheral edema is of ten assessed by medical prof essionals to gain insights about development of many patient conditions. Currently, doctors assess edema by pushing on the swollen area of a patient. The difficulty with this method is the inconsistency assessment results between different physicians due to the subjective nature of the practice. The proposed solution uses AERO (or Air Edema RepOrting), a mobile, handheld device consisting of a high-speed camera with a macro lens, LED light, and compressed air to create edema indentation and capture images of the skin /tissue response. A MATLAB program analyzes these images and determines the correct level of edema. AERO was tested with a LifeformOR pitting edema trainer (four pieces of skin sample that represent the four edema levels). Various system configurations, such as the air pressure, camera to sample distance, and air incidence angle, were examined and optimal parameters were identified. Results demonstrated that AERO was able to distinguish the four levels of edema sample pads. This solution can potentially provide a quantified, standard evaluation of peripheral edema for both home and health care environments.

A Browser-Server-Based Tele-audiology System That Supports Multiple Hearing Test Modalities.

INTRODUCTION: Millions of global citizens suffering from hearing disorders have limited or no access to much needed hearing healthcare. Although tele-audiology presents a solution to alleviate this problem, existing remote hearing diagnosis systems support only pure-tone tests, leaving speech and other test procedures unsolved, due to the lack of software and hardware to enable communication required between audiologists and their remote patients. This article presents a comprehensive remote hearing test system that integrates the two most needed hearing test procedures: a pure-tone audiogram and a speech test. MATERIALS AND METHODS: This enhanced system is composed of a Web application server, an embedded smart Internet-Bluetooth(®) (Bluetooth SIG, Kirkland, WA) gateway (or console device), and a Bluetooth-enabled audiometer. Several graphical user interfaces and a relational database are hosted on the application server. The console device has been designed to support the tests and auxiliary communication between the local site and the remote site. RESULTS: The study was conducted at an audiology laboratory. Pure-tone audiogram and speech test results from volunteers tested with this tele-audiology system are comparable with results from the traditional face-to-face approach. CONCLUSIONS: This browser-server-based comprehensive tele-audiology offers a flexible platform to expand hearing services to traditionally underserved groups.

Audiology telepractice in a clinical environment: a communication perspective.

Access to adequate hearing health care is an obstacle that many individuals face worldwide. The prospect of providing audiology services via the Internet is an attractive and viable alternative to traditional face-to-face interaction between patients and audiologists, thus affording improved access to hearing health care for traditionally underserved populations. This article details our experience of using a web-based system with wireless audiometers and videoconferencing software to administer remote audiological assessments in an active medical practice. It discusses the technological infrastructure used and the pragmatic issues that arise when the Internet, Bluetooth wireless audiometers, and videoconferencing devices are converged into a clinical setting. Patients at a local office of otolaryngologists were recruited to participate in a study in which remote assessment results were compared to those collected from a traditional face-to-face assessment. Preliminary data demonstrated that the assessment results from the two sources were comparable. We conclude that remote hearing assessment over the Internet can be achieved through a distributed system synthesized with Internet, wireless communication, and videoconferencing technologies, supported by appropriate staff.

iHandRehab: an interactive hand exoskeleton for active and passive rehabilitation.

This paper presents an interactive exoskeleton device for hand rehabilitation, iHandRehab, which aims to satisfy the essential requirements for both active and passive rehabilitation motions. iHandRehab is comprised of exoskeletons for the thumb and index finger. These exoskeletons are driven by distant actuation modules through a cable/sheath transmission mechanism. The exoskeleton for each finger has 4 degrees of freedom (DOF), providing independent control for all finger joints. The joint motion is accomplished by a parallelogram mechanism so that the joints of the device and their corresponding finger joints have the same angular displacement when they rotate. Thanks to this design, the joint angles can be measured by sensors real time and high level motion control is therefore made very simple without the need of complicated kinematics. The paper also discusses important issues when the device is used by different patients, including its adjustable joint range of motion (ROM) and adjustable range of phalanx length (ROPL). Experimentally collected data show that the achieved ROM is close to that of a healthy hand and the ROPL covers the size of a typical hand, satisfying the size need of regular hand rehabilitation. In order to evaluate the performance when it works as a haptic device in active mode, the equivalent moment of inertia (MOI) of the device is calculated. The results prove that the device has low inertia which is critical in order to obtain good backdrivability. Experimental analysis shows that the influence of friction accounts for a large portion of the driving torque and warrants future investigation.

Using web services to realize remote hearing assessment.

BACKGROUND: Internet-based tele-audiology is expected to relieve the dilemma between the lack of resources and high demand of audiological care services. This paper presents a web services based, distributed pure-tone hearing assessment system that improves accessibility of traditionally underserved groups to audiology care. METHODS: The system employs browser-server network architecture to connect patients to audiology specialists through a web server where all application software is hosted. Software on the server is designed with a three-tier approach which makes the system scalable to include other audiological services. Hearing test data are stored in a standard database and can potentially be integrated into established electronic medical records. On the remote patient side, off-the-shelf audiometers are adopted. The Internet connection of these audiometers can be flexibly configured either with or without a computer. Two aspects of the system were tested: (1) the clinical effectiveness of the system: double-blinded experiments were conducted to assess hearing ability of 30 subjects and paired t-tests were utilized to compare assessment results from the remote approach and the conventional setup; and (2) to analyze the system bandwidth requirements, data traffic among the server, the audiometer, and the audiologist terminal was examined with a network monitoring software (wireshark). RESULTS: Paired t-test results have demonstrated that the remote hearing assessment is equivalent in effectiveness to its conventional counterparts at all tested frequencies (P values are in the range of [0.12, 0.94]), and the bandwidth required by the system is less than 1 Mbps, falling within the capacity of average commercial Internet service subscription. CONCLUSIONS: The project developed a remote hearing assessment system based on services on a web server. The system minimizes hardware and software requirements on the audiologist's computer and can be realized with regular Internet service subscription. Patient operations involved in hearing assessment are simple; making hearing test services more accessible to those otherwise may not be able to obtain the desired hearing care.

Design of a Web services based system for remote hearing diagnosis.

This paper presents a web services based, distributed system that allows remote pure tone hearing tests. The system network follows browser-server architecture, which minimizes hardware and software requirements on the client computers and makes hearing test services more accessible to traditionally underserved population groups. Thanks to the three tier software design, the system functionality is easily scalable to include other audiological services. Since testing data are stored in a standard database, they can be potentially integrated into established electronic medical records.

An orthopedic injection training instrument using flow impedance to indicate needle tip locations.

OBJECTIVE: The project aimed to design an instrument that can provide visual, quantitative feedback to medical students and help them develop intuitive, tactile-based injection skills. METHODS: The instrument uses force and displacement sensors to find flow impedance, the ratio of the pressure applied to fluid in the syringe to the fluid flow rate, of different tissues. A software program utilizes these flow impedances to identify needle tip location-either joint or tendon. Injection experiments with pork feet were completed to collect flow impedance data when the needle tip was located in joint or tendon. Injections used deionized water and aqueous pullulan solutions to study the instrument's effectiveness when medical therapies of different viscosities are injected. For each solution, at least 13 injections were conducted. The mean and standard deviation of the flow impedances from injections with each solution were obtained. RESULTS: In all experimental cases, the flow impedance demonstrated by the tendon is a number of times higher than that of the joint cavity: the impedance ratios (tendon to joint cavity) for water, 3 w/w% pullulan, and 15 w/w% pullulan are 74, 62, and 6, respectively. CONCLUSIONS: The results confirmed the concept of using flow impedance to index the needle tip location-whether the tip is positioned in joint or tendon. This instrument's user interface can serve as a training aid for medical students and infrequent operators.

A Web services-based distributed system with browser-client architecture to promote tele-audiology assessment.

The purpose of this research was to extend applications of the Internet and other telecommunication means to the assessment of hearing. The newly developed distributed system consists primarily of an application server and its database, and Web services under browser-server architecture to support remote hearing assessment. A pilot study was conducted: three independent audiologists assessed hearing of 25 subjects using testing approaches with different data communication configurations. Analysis of the results demonstrated the feasibility of replacing conventional "face-to-face" tests with the remote hearing tests using the distributed system. Because of its distributed architecture, the present system supports a new service model and separates technical maintenance and clinical services. Consequently, the system shows great potential to benefit the clinical hearing care profession. Future research is planned to apply this system to medical facilities and for distance applications.

A pilot study on using derivatives of photoplethysmographic signals as a biometric identifier.

Photoplethysmographic (PPG) signals are easy to obtain with low cost, which enhances its potential to server as biometric identification mechanism for various applications. This paper examines two important issues in applying derivatives of PPG signals as discriminants to identify and verify subjects: consistency within an individual subject and discriminability between different subjects. The experimental results demonstrate that, by employing statistical tools, derivatives can precisely describe the features of an individual's PPG signal and be used as bio-measures for identification purposes.

A wearable point-of-care system for home use that incorporates plug-and-play and wireless standards.

A point-of-care system for continuous health monitoring should be wearable, easy to use, and affordable to promote patient independence and facilitate acceptance of new home healthcare technology. Reconfigurability, interoperability, and scalability are important. Standardization supports these requirements, and encourages an open market where lower product prices result from vendor competition. This paper first discusses candidate standards for wireless communication, plug-and-play device interoperability, and medical information exchange in point-of-care systems. It then addresses the design and implementation of a wearable, plug-and-play system for home care which adopts the IEEE 1073 Medical Information Bus (MIB) standards, and uses Bluetooth as the wireless communication protocol. This standards-based system maximizes user mobility by incorporating a three-level architecture populated by base stations, wearable data loggers, and wearable sensors. Design issues include the implementation of the MIB standards on microcontroller-driven embedded devices, low power consumption, wireless data exchange, and data storage and transmission in a reconfigurable body-area network.

A short study to assess the potential of independent component analysis for motion artifact separation in wearable pulse oximeter signals.

Motion artifact reduction and separation become critical when medical sensors are used in wearable monitoring scenarios. Previous research has demonstrated that independent component analysis (ICA) can be applied to pulse oximeter signals to separate photoplethysmographic (PPG) data from motion artifacts, ambient light, and other interference in low-motion environments. However, ICA assumes that all source signal component pairs are mutually independent. It is important to assess the statistical independence of the source components in PPG data, especially if ICA is to be applied in ambulatory monitoring environments, where motion artifacts can have a substantial effect on the quality of data received from light-based sensors. This paper addresses the statistical relationship between motion artifacts and PPG data by calculating the correlation coefficients between arterial volume variations and motion over a range of stationary to high-motion conditions. Analyses indicate that motion significantly affects arterial flow, so care must be taken when applying ICA to light-based sensor data acquired from wearable platforms.

Interoperability and security in wireless body area network infrastructures.

Wireless body area networks (WBANs) and their supporting information infrastructures offer unprecedented opportunities to monitor state of health without constraining the activities of a wearer. These mobile point-of-care systems are now realizable due to the convergence of technologies such as low-power wireless communication standards, plug-and-play device buses, off-the-shelf development kits for low-power microcontrollers, handheld computers, electronic medical records, and the Internet. To increase acceptance of personal monitoring technology while lowering equipment cost, advances must be made in interoperability (at both the system and device levels) and security. This paper presents an overview of WBAN infrastructure work in these areas currently underway in the Medical Component Design Laboratory at Kansas State University (KSU) and at the University of Alabama in Huntsville (UAH). KSU efforts include the development of wearable health status monitoring systems that utilize ISO/IEEE 11073, Bluetooth, Health Level 7, and OpenEMed. WBAN efforts at UAH include the development of wearable activity and health monitors that incorporate ZigBee-compliant wireless sensor platforms with hardware-level encryption and the TinyOS development environment. WBAN infrastructures are complex, requiring many functional support elements. To realize these infrastructures through collaborative efforts, organizations such as KSU and UAH must define and utilize standard interfaces, nomenclature, and security approaches.

Applying the ISO/IEEE 11073 standards to wearable home health monitoring systems.

OBJECTIVE: The goal of this effort was to investigate the feasibility of applying the ISO/IEEE 11073 (a.k.a. X73) standards, originally intended for bedside monitoring in hospital environments, to wearable, multi-sensor monitoring systems designed for home healthcare. METHODS: The X73 upper-layer sub-standards (i.e., nomenclature specification, domain information model, application profiles, and vital sign device descriptions) were adopted and implemented on microcontroller-based sensor hardware to provide plug-and-play medical components. Three types of system elements (base stations, data loggers, and sensor units) perform the functionality required in this standards-based home health monitoring system and communicate using Bluetooth wireless modules. The base station incorporates a LabVIEW interface running on a personal computer. Each data logger and sensor unit is implemented on a microcontroller-driven embedded platform. Sensor units include wearable sensors (e.g., electrocardiograph, pulse oximeter) and nearby sensors (e.g., weight scale, ambient environment sensors). RESULTS: The standards-based prototype system with an open architecture achieves plug-and-play performance suitable for a home environment. Each wireless element in the body/home area network can automatically detect other nearby devices, associate with them, and exchange data with them as appropriate. CONCLUSIONS: With minor modifications, the X73 standards can be successfully applied to wearable, wireless, point-of-care systems in the home.

Reconfigurable point-of-care systems designed with interoperability standards.

Interoperability standards, if properly applied to medical system design, have the potential to decrease the cost of point-of-care monitoring systems while better matching systems to patient needs. This paper presents a brief editorial overview of future monitoring environments, followed by a short listing of smart-home and wearable-device efforts. This is followed by a summary of recent efforts in the Medical Component Design Laboratory at Kansas State University to address interoperability issues in point-of-care systems by incorporating the Bluetooth Host Controller Interface, the IEEE 1073 Medical Information Bus, and Health Level 7 (HL7) into a monitoring system that hosts wearable or nearby wireless devices. This wireless demonstration system includes a wearable electrocardiogram, wearable pulse oximeter, wearable data logger, weight scale, and LabVIEW base station. Data are exchanged between local and remote MySQL databases using the HL7 standard for medical information exchange.

A novel algorithm to separate motion artifacts from photoplethysmographic signals obtained with a reflectance pulse oximeter.

Pulse oximeters are mainstays for acquiring blood oxygen saturation in static environments such as hospital rooms. However, motion artifacts prevent their broad in wearable, ambulatory environments. To this end, we present a novel algorithm to separate the motion artifacts from plethysmographic data gathered by pulse oximeters. This algorithm, based on the Beer-Lambert law, requires photoplethysmographic data acquired at three excitation wavelengths. The algorithm can calculate venous blood oxygen saturation (SvO2) as well as arterial blood oxygen saturation (SaO2). Preliminary results indicate that the extraction of the venous signal, which is assumed to be most affected by motions, is successful with data acquired from a reflectance-mode sensor.