- Adjuvant Heart Rate Variability Biointerventions for Combat-Related PTSD
- Prosthetic Knee-Ankle-Foot System With Biomechatronic Sensing, Control, and Power Generation
- Reconstruction of Facial Cartilage Frameworks Using Electromechanical Reshaping
Currently, there are few highly effective treatment options for patients suffering from post-traumatic stress disorder (PTSD). In addition, associated deficits in attention and immediate memory remain a serious issue for patients with PTSD. While lowered heart rate variability (the small beat-to-beat changes in heart rate) has been shown to be associated with PTSD, this association has not been well-studied. The heart beats at a changing rate and variability in heart rate can affect physical, emotional and mental well-being. These changes in heart rate are natural and are a sign of health. A therapeutic intervention called heart rate variability biofeedback (HRVB) is a novel technique that has successfully been used to treat patients with various medical and psychiatric conditions. HRVB teaches patients to change the variability and rhythms in heart activity through attention focusing, resonant frequency breathing, imagery, and positive emotion induction.
Dr. J.P. Ginsberg and colleague are investigating the clinical use of HRVB for PTSD-induced deficits in concentration and memory recall in post-combat veterans diagnosed with PTSD. Preliminary data gathered by Dr. Ginsberg showed that HRVB increased coping ability and improved thinking and memory in OIF/OEF veterans with PTSD. Dr. Ginsberg is extending these preliminary findings in a larger population of OIF/OEF veterans. Patients enrolled in the study will learn the biofeedback techniques with a trained biofeedback practitioner to improve their heart rate variability. Currently, subject enrollment, training and assessment are ongoing. It is anticipated that this study will reduce or eliminate deleterious physiological and cognitive effects associated with PTSD and ultimately increase functional adjustment to everyday and acute stressors in veterans with PTSD.
Preliminary data taken from all subjects at the time of entry into the study does provide support for the hypothesis that PTSD impairs accuracy of early stage information processing, compared to normative populations. Results of treatment effects of the intervention cannot be reported at this time because study blinding has not been broken.
Prosthetic Knee-Ankle-Foot System With Biomechatronic Sensing, Control, and Power Generation
Posted September 7, 2012
Arthur Kuo, Ph.D., University of Michigan
Hugh Kerr, Ph.D., Massachusetts Institute of Technology
Glenn Klute, Ph.D., Seattle Institute for Biomedical and Clinical Research
The number of veterans living with lower limb amputations is an expanding population in the armed forces and the Veterans Administration System. Amputees experience reduced comfort, endurance, and mobility, decreasing their ability to return to active duty and to participate in the workforce. Computer-controlled prosthetic devices have improved some aspects of mobility, but the energy expenditure of walking remains much higher for amputees than able-bodied persons. A team of researchers brought together under an FY08 DRMRP Advanced Technology/Therapeutic Development Award are working to develop new technology to improve mobility with computer-controlled prosthetic knees and ankles that will harvest energy from the user and thus have lower external energy requirements than existing devices.
Dr. Arthur Kuo at the University of Michigan, Dr. Hugh Kerr at the Massachusetts Institute of Technology (MIT) and Dr. Glenn Klute at the Seattle Institute for Biomedical and Clinical Research aim to develop a prosthetic knee-ankle-foot system that actively coordinates the joints using multi-modal biomechatronic sensory data to integrate user intent and control. A key innovation in the project is how the knee and ankle-foot prostheses will be computer-controlled, but self-powered by harvesting energy from the user. The researchers hypothesize that sufficient energy can be generated from passive knee motion to power a prosthesis with minimal user effort, and that elastic energy can be captured from the ankle action to assist with a pushing off motion.
The electromechanics / electronics integration components of prototype prostheses are being developed and fabricated by the Michigan and MIT groups. Knee and foot prototypes are being tested by amputees with encouraging preliminary results. The Seattle group is developing a prosthesis-embedded instrument to measure and record environmental, physiologic, activity and performance/diagnostic metrics, to include developing sensing algorithms to detect ambulatory mode, user intent and varying terrain.
This project has the potential to significantly improve the function of leg prostheses by reducing the energy need from the user and offering improved adjustment to uneven terrain, like stair descent. Furthermore, the project will develop new devices for assessing and quantifying the long-term usage of prostheses in daily living, providing a valuable data resource for future technological advances.
For more than a century, surgeons have envisioned reshaping tissue to correct defects in the face and neck resulting from combat injuries, trauma, burns, or birth defects. Combat related injuries sometimes require complete reconstruction of the ear or nose which requires vast amounts of cartilage. Cartilage is a flexible connective tissue with properties of both hard and soft tissues found in the nose, ear, larynx, and trachea. Although ribs harbor massive amounts of cartilage, most of it warps and cannot be used for facial reconstruction using conventional methods. Dr. Wong and colleagues have developed a novel technology referred to as electromechanical reshaping (EMR) to allow surgeons to bend cartilage into the shape they desire by simply inserting platinum plated needles and then applying electrical current. To provide the necessary information to bring EMR into surgical practice, Dr. Wong received funding from a Fiscal Year 2008 Advanced Technology/Therapeutic Development Award to reconstruct ear defects in animals using EMR.
Dr. Wong first studied the anatomy of rabbit rib cages and ears to determine the best rib cartilage for production of a graft and the best site for implantation into the ear. Based on length, thickness, and width measurements as well as a statistical analysis of rib and ear geometry, he identified the best grafting cartilage (sixth rib) and the implant site (base of the ear). To reshape the grafting cartilage, prototype reshaping jigs were designed and built based on geometrical analysis of cartilage in the ear. To produce consistent and uniform thickness grafts, Dr. Wong's team developed and practiced graft extraction and closure from the thoracic donor site in animals. A series of numerical simulations and reshaping experiments were then performed to determine optimal electrode placement geometry, voltage, and application time and the results showed that a low voltage can reshape cartilage grafts within several minutes and without the heat generation.
Dr. Wong concludes that EMR can provide a new means to reshape rib cartilage and existing cartilage tissues that may then be fully exploited to rebuild face and airway structures of both military personnel injured in combat and civilians with injuries or birth defects. Since EMR is a low risk, needle-based technology, it is amenable to endoscopic methods, potentially converting traditionally open operations used in major airway reconstructive surgery to a minimally invasive procedure. Dr. Wong believes EMR can be rapidly moved into advanced clinical development and could represent a major breakthrough in facial/aural rehabilitative reconstructive surgery. In fact, EMR technology patented in 2008 (under both NIH and DOD support) is already being commercialized by two companies, and may have applications in orthopedics and ophthalmology as well.