WHMS - Wearable Health Monitoring Systems

Electrical and Computer Engineering
The University of Alabama in Huntsville

In colaboration with:
Mayo Clinic
Kansas State University
Perl Research
Naval Aerospace Medical Research Lab NAMRL

System Overview
Wireless Intelligent Sensors
Wireless Gateways
Selected Publications

Test data and processing procedures for Matlab.
Dataset recorded during ISSS-MDBS06 demonstration. Dataset recorded during MCTPH07 in Melbourne, and experimental setup and description .

Wearable health monitoring systems integrated into a telemedicine system are novel information technology that will be able to support early detection of abnormal conditions and prevention of its serious consequences. Many patients can benefit from continuous ambulatory monitoring as a part of a diagnostic procedure, optimal maintenance of a chronic condition or during supervised recovery from an acute event or surgical procedure.
Important limitations for wider acceptance of the existing systems for continuous monitoring are: Traditionally, personal medical monitoring systems, such as Holter monitors, have been used only to collect data for off-line processing. Systems with multiple sensors for physical rehabilitation feature unwieldy wires between electrodes and the monitoring system. These wires may limit the patient's activity and level of comfort and thus negatively influence the measured results. A wearable health-monitoring device using a Personal Area Network (PAN) or Body Area Network (BAN) can be integrated into a user's clothing.
Recent technology advances in wireless networking, micro-fabrication, and integration of physical sensors, embedded microcontrollers and radio interfaces on a single chip, promise a new generation of wireless sensors suitable for many applications, such as stroke rehabilitation, physical rehabilitation after hip or knee surgeries, myocardial infarction rehabilitation, and traumatic brain injury rehabilitation.

Increased system processing power allows sophisticated real-time data processing on sensors, which reduces wireless channel utilization and power consumption. We propose a wireless BAN composed of off-the-shelf sensor platforms with application-specific signal conditioning modules.

System Overview
A general multi-tier system architecture is shown in Figure 1; the lowest level encompasses a set of intelligent physiological sensors; the second level is the personal server (Internet enabled PDA, cell-phone, or home computer); and the third level encompasses a network of remote health care servers and related services (Caregiver, Physician, Clinic, Emergency, Weather).
Each level represents a fairly complex subsystem with a local hierarchy employed to ensure efficiency, portability, security, and reduced cost. The personal server, running on a PDA or a 3G cell phone, provides the human-computer interface and communicates with the remote server(s).


Figure 1. Wireless Body Area Network of Intelligent Sensors for Ambulatory Health Monitoring

Wireless Intelligent Sensors
We developed several generations of wireless intelligents sensors at the University of Alabama in Huntsville. We started with MSP430 family and custom wireless interface in 2000; we currently use off-the-shelf wireless sensors with the same microcontroller family and custom signal processing boards. Some of our projects are presented below.

ISPM_v3 (Intelligent Signal Processing Module), 2005

Features MSP430F1611 microcontroller, one ECG channel, one 3D accelerometer; Designed as a daugther card for Tmote Sky wireless platform.
Figure 1. ISPM_v3 sensor card with one bioamplifier channel and on-board 3D accelerometer (U2 on the back side).

Telos_HRV, 2005
Wireless sensor for heart rate chest belts, such as Polar; Designed as a daugther card for Tmote Sky wireless platform.
Figure 2. Telos_HRV heart rate sensor.

ISPM_v2 (
Intelligent Signal Processing Module), 2005
Features MSP430F1232, two ECG channels, accelerometers; Designed as a daugther card for Tmote Sky wireless platform.
Figure 3. ISPM_v2 sensor card with two bioamplifier channels.

IAS_v1 (Intelligent Activity Sensor), 2005
Features MSP430F1232, one on-board 2D accelerometer and connector for the second 2D accelerometer, and signal conditioning for the force resistor sensor used as a foot switch (see Figure 4); Designed as a daugther card for Tmote Sky wireless platform.

ISPM_v1 (Intelligent Signal Processing Module), 2004-2005
Features MSP430F1232, one ECG channel, two 2D accelerometers; Designed as a daugther card for Tmote Sky wireless platform.
Figure 4. ISPM_v1 and IAS sensors on Telos sensor platforms. Second accelerometer and foot switch (force sense resistor) connected to IAS board.

Reconfigurable Pulse Oximeter Sensor , 2003-2004
Features MSP430F149, reconfigurable CPLD, RS232 interface, and pulse oximeter signal conditioning circuit. Senior design project of Shane Basham, David Kelley, and Drake Clark.

Figure 5. Reconfigurable Pulse Oximeter Sensor.

WHRM Wireless Heart Rate Monitoring Sensor, 2002-2003
Distributed stress monitoring system developed for Naval Aerospace Medical Research Lab (NAMRL) for stress monitoring during training.
Figure 6. WHRM - wireless heart rate monitor.

WISE_v4, 2003
Features MSP430F149, LINX wireless transceiver, standard 2 channel TETMD bioamplifier.
Figure 7. WISE_v4; the second reincarnation of original sensors with standard bio amplifier. Graduate project of Brent Priddy.

WISE_v3, 2001
Features     MSP430F149 microcontroller and 2D MEMS accelerometer ADXL202.
Figure 8. WISE_v3; the first wireless intelligent sensor with ADXL MEMS accelerometer.

WISE_v2, 2001
Features MSP430F149, one channel ECG amplifier, and 900MHz wireless transceiver.
Figure 9. WISE_ECG1; our first wireless intelligent sensor with on-board ECG amplifier.

WISE_breathing_sensor, 2001
Early wireless sensor for long-term estimation of nostril symmetry.
WISE breathing
Figure 10. WISE_breathing - wireless breathing sensor.

WISE_v1, 2000
Features MSP430F1121, off-the-shelf two channel bioamplifer, 900 MHz wireless interface.
Figure 11. Wireless Intelligent Sensor WISE - the first reincarnation.

Wireless Gateways

Compact Flash Zigbee-compliant Network Coordinator
, 2005
Features Philips LPC2138 microcontroller with ARM7TDMI-S CPU running at 60MHz. We truly appreciate help of Curtis Mead and Matt Welsh from Harvard University.
Figure 12. Compact flash ZigBee network coordianator.

Custom Wireless Gateway, 2003
An early version of RS232 wireless interface to PDA/PC.
Figure 13. Custom 900MHz wireless gateway with LINX transceiver.

Sample datasets

SAMPLE DATASET from Actis activity sensor is provided for research community. This is a 60 second example which includes sitting-walking-sitting activity, written as a standard ASCII file (space separated values) with four vectors: The sensor is mounted above the knee.

Figure 14. Orientation of axis on the activity sensor Actis.






Selected Publications

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