Modular Wound Therapy System (mWTS)
Modular Wound Therapy System (mWTS)
Principal Investigator: Kath Bogie, D.Phil.
Co-Investigators: Steven Garverick, Ph.D. & Christian Zorman, Ph.D.
Staff/Students: Jeremy Dunning, M.S.; B.S.; & Daniel Howe, B.S, Allison Hess
Description
The overall goal of this project is to develop a wireless surface electrical stimulation system (mWTS) combining the use of advanced materials, fabrication techniques and design together with a simple, user-friendly communication interface in a novel medical device costing less than $100. It consists of a flexible substrate, battery, and custom integrated circuitry integrated into a conforming occlusive dressing. The device can be applied over a chronic wound as a bandage (for days or weeks at a time) and deliver therapeutic electrical currents to accelerate healing wirelessly. The device can then be simply removed, disposed of, and replaced to continue treatment. The mWTS will be a therapeutic electrical stimulation device that achieves high efficacy and safety and high acceptance by both clinicians and user. This project will develop a reliable and effective disposable wound therapy stimulation system that will improve ease of use and acceptance by both users and clinicians. Multiple therapeutic applications in acute clinical care and rehabilitation would be positively affected by utilization of electrical stimulation (ES) as a platform modality. This project will thus provide the basis for the further development of a novel surface stimulation platform technology with the potential for widespread clinical utility both within the VA Health Care System and in other health care settings.
Objectives
To establish the proof of concept for the mWTS through the design and preliminary testing of a prototype device. To implement use of the mWTS in the rat chronic ischemic wound model.
Research Plan & Methodology
A preliminary mWTS has been developed by our team as a semi-flexible device. The electronics, communications components and lithium battery power
supply are mounted on a rigid printed circuit board (PCB). The PCB is mounted on a 4x3cm flexible medical-grade polyimide substrate with sputter-plated platinum stimulating electrodes designed for use in our animal model. There is an infrared (IrDA®) bi-directional wireless communications interface to enable user command via an on-board microcontroller that can adjust stimulation variables. The electronic design employed an adaptable architecture that facilitates future functional adaptations. The on-board microcontroller is easily reprogrammed to communicate new clinical stimulation protocols. The capability for reprogrammable functions, including actuator timing, sensor data acquisition, sensor data storage, and communications host allows evaluation of the effects of varying ES conditions and can monitor device function in pre-clinical testing. In clinical use, the ability to vary stimulation protocols provides the potential for customized use of the mWTS.
Preliminary Results
Complete evaluation of the individual components of the mWTS and benchtop testing of a working prototype to determine electrical and mechanical functionality under simulated animal testing conditions has been completed. A prototype flexible mWTS was implemented in our rabbit ischemic wound model. The mWTS was attached to the animal with a medical grade pressure sensitive adhesive and preliminary device function and communication was tested. The external communications protocol allowed two-way communication to both control the stimulation variables and download information on wound status.
Milestones
Training in a new chronic ischemic wound animal model will commence in the 2nd quarter of 2008. A pilot series of animal testing using the prototype flexible mWTS will be carried out in the third quarter of 2008, which will result in information necessary to optimize the design of the integrated circuit by the end of the year. Preparation for production and qualification for human testing will follow.
Future Grant & Publication Plans
In addition to the VA Rehabilitation Research and Development grant application reported in B1: Project Submissions/Approvals, the following grant application is in preparation.
NAKFI Futures Grant:
Aging and healing of chronic wounds: development of a chronic ischemic wound animal model. Submission is anticipated for February 2008.
Clinical Relevance
Electrical stimulation has been recommended for treatment of chronic wounds however this therapeutic modality is limited by the technology currently available. The mWTS will provide a major new tool in wound care because it will allow patients to receive continuous ES therapy within the optimal wound healing microenvironment without further restricting mobility. A communications interface will allow clinicians to control and monitor therapy using readily available devices, such a laptop or PDA.
The mWTS will apply leading-edge technology and design to significantly advance the field of wound care with a novel medical device that is well accepted by both clinicians and users. Furthermore, the mWTS will have the potential to improve clinical care for many conditions that may require short- to medium-term therapeutic electrical stimulation.
On completion of pre-clinical testing using the new animal model our goal is to carry out pilot clinical trials in collaboration with both the Spinal Cord Injury and Disability (SCI/D) and Podiatry Services of the Cleveland VAMC.
