Researchers from the University of Houston have shown for the first time that the use of a brain-computer interface augmented with a virtual walking avatar can control gait, suggesting the protocol may help patients recover the ability to walk after stroke, some spinal cord injuries and certain other gait disabilities.
Researchers said the work, done at the University’s Non-invasive Brain-Machine Interface System Laboratory, is the first to demonstrate that a brain-computer interface can promote and enhance cortical involvement during walking.
Jose Luis Contreras-Vidal, Cullen professor of electrical and computer engineering at UH and senior author of the paper, said the data will be made available to other researchers. While similar work has been done in other primates, this is the first to involve humans, he said. Contreras-Vidal is also site director of the BRAIN Center (Building Reliable Advances and Innovation in Neurotechnology), a National Science Foundation Industry/University Cooperative Research Center.
Contreras-Vidal and researchers with his lab use non-invasive brain monitoring to determine what parts of the brain are involved in an activity, using that information to create an algorithm, or a brain-machine interface, which can translate the subject’s intentions into action.
“Voluntary control of movements is crucial for motor learning and physical rehabilitation,” they wrote. “Our results suggest the possible benefits of using a closed-loop EEG-based BCI-VR (brain-computer interface-virtual reality) system in inducing voluntary control of human gait.”
Researchers already knew electroencephalogram (EEG) readings of brain activity can distinguish whether a subject is standing still or walking. But they hadn’t previously known if a brain-computer interface was practical for helping to promote the ability to walk, or what parts of the brain are relevant to determining gait.
In this case, they collected data from eight healthy subjects, all of whom participated in three trials involving walking on a treadmill while watching an avatar displayed on a monitor. The volunteers were fitted with a 64-channel headset and motion sensors at the hip, knee and ankle joint.
The avatar first was activated by the motion sensors, allowing its movement to precisely mimic that of the test subject. In later tests, the avatar was controlled by the brain-computer interface, meaning the subject controlled the avatar with his or her brain.
The avatar perfectly mimicked the subject’s movements when relying upon the sensors, but the match was less precise when the brain-computer interface was used.
Contreras-Vidal said that’s to be expected, noting that other studies have shown some initial decoding errors as the subject learns to use the interface. “It’s like learning to use a new tool or sport,” he said. “You have to understand how the tool works. The brain needs time to learn that.”
The researchers reported increased activity in the posterior parietal cortex and the inferior parietal lobe, along with increased involvement of the anterior cingulate cortex, which is involved in motor learning and error monitoring.

University of Houstonhttp://tinyurl.com/y9p8o5dr

One of the first studies testing the effectiveness of different operating room (OR) head coverings in preventing airborne contamination has found that surgeon’s caps that expose small amounts of the ears and hair are not inferior to the bouffant-style, disposable scrub hats that cover those features.
“Recently there have been concerns that exposed hair in the OR could increase the risk of surgical site infections, although there is no definitive evidence that it does,” said principal investigator Troy A. Markel, MD, FACS, assistant professor of Paediatric surgery at Riley Hospital for Children at Indiana University Health, Indianapolis. “In fact, there are very few published scientific data supporting what the optimal headgear in the OR is.”
For their study, the researchers tested three common styles of commercially available surgical headgear. Disposable shower cap-like bouffant hats underwent testing, as did two types of surgical skullcaps, another name for the tie-in-the-back, close-fitting caps that are popular with surgeons: disposable caps with paper sides, and freshly home-laundered, reusable, cloth skullcaps.
Unlike most tests for environmental quality, which Dr. Markel said are typically done in a static laboratory, their airborne contamination testing was performed in an actual OR under changing conditions. For each style of hat the OR team wore, they performed a one-hour mock operation, which included gowning and gloving, passing surgical instruments, leaving and re-entering the OR, and performing electrocautery on a piece of raw steak to generate particles that were discharged into the air. Each hat style underwent testing four times, twice at each of two different hospitals. Both ORs had high-efficiency air-cleansing ventilation systems, according to the researchers.
The multidisciplinary research team—a microbiologist, engineers specializing in ventilation, an industrial air hygienist, and a surgeon—used their previously developed method involving multiple tests of what they call environmental quality indicators. In one test using a particle counter, they counted tiny airborne particles, such as hair and skin cells, that landed in various parts of the room. They also measured microbial shedding, the bacteria and other micro-organisms collected and grown in Petri dishes placed at the sterile operating field and the instrument table in the back of the room.
During the mock operations, the bouffant hats and the disposable surgical skullcaps had similar airborne particle counts, the study investigators reported. However, cloth skullcaps, which do not have a porous crown like their disposable counterparts, reportedly outperformed bouffant hats, showing lower particle counts and significantly lower microbial shedding at the sterile field compared with bouffant hats.
Additionally, the investigators tested the fabric of each hat style for permeability (air flow), penetration (amounts of particles that pass through), and porosity (pore, or hole, size). Results of fabric analysis revealed that the bouffant hats had greater permeability than either of the other caps, the investigators reported.
“Some organizations and hospitals have suggested that all OR personnel wear disposable bouffant-type hats, but we found no apparent infection-control reason to disallow disposable skullcaps in the OR,” Dr. Markel reported.
The researchers did not compare the amounts of airborne contaminants with infections at the surgical site. However, because they observed no statistically significant difference in the amounts of airborne contaminants in the OR between the disposable skullcaps and the disposable bouffant hats, he said, “I think it is difficult to say that one disposable hat is better than the other to prevent surgical site infections.”
Their study results have the potential to make an impact on the OR attire policies of hospitals and health care regulatory bodies, according to Dr. Markel.
“I expect our findings may be used to inform surgical headgear policy in the United States,” he said. “Based on these experiments, surgeons should be allowed to wear either a bouffant hat or a skullcap, although cloth skull caps are the thickest and have the lowest permeability of the three types we tested.”
American College of Surgeons
www.facs.org/media/press-releases/2017/markel

With the use of implanted cardiac monitors researchers found a substantial incidence (nearly 30 percent) of previously undiagnosed atrial fibrillation (AF) after 18 months in patients at high risk of both AF and stroke, according to a study.
Atrial fibrillation affects millions of people worldwide and increases with older age, hypertension, diabetes, and heart failure, conditions that are associated with increased stroke risk. Atrial fibrillation episodes may be symptomatic, asymptomatic (i.e., silent AF), or both. Heart failure or stroke can be the first clinical manifestation of AF. Recognition of previously undiagnosed AF and initiation of appropriate therapies is essential for stroke prevention.
Minimally invasive prolonged electrocardiographic monitoring with small, insertable cardiac monitors (ICMs) placed under the skin could assist with early AF diagnosis and earlier treatment. James A. Reiffel, M.D., of the Columbia University College of Physicians and Surgeons, New York, and colleagues conducted a study in which 385 patients received an insertable cardiac monitor. The patients were at high risk of both AF and stroke; approximately 90 percent had nonspecific symptoms potentially compatible with AF, such as fatigue, breathing difficulties, and/or palpitations, and had either three or more of heart failure, hypertension, age 75 or older, diabetes, prior stroke or transient ischemic attack (TIA), or two of the former plus at least one of the following additional AF risk factors: coronary artery disease, renal impairment, sleep apnea, or chronic obstructive pulmonary disease. Patients underwent monitoring for 18 to 30 months.
The researchers found that the detection rate of AF lasting six or more minutes at 18 months was 29 percent. Detection rates at 30 days and 6, 12, 24, and 30 months were 6 percent, 20 percent, 27 percent, 34 percent, and 40 percent, respectively. Median time from device insertion to first AF episode detection was 123 days. Of patients with AF lasting six or more minutes at 18 months, 10 percent had one or more episodes lasting 24 hours or longer, and oral anticoagulation therapy was prescribed for 72 patients (56 percent).
The study notes some limitations, including its modest size.
The authors write that as the AF incidence was still rising at 30 months, the ideal monitoring duration is unclear. "Further trials regarding the value of detecting subclinical AF and of prophylactic therapies are warranted."

ScienceDaily www.sciencedaily.com/releases/2017/08/170827101755.htm

Guidelines on the management of acute myocardial infarction in patients with ST-segment elevation have been published.
The document provides recommendations on topics not covered by the 2012 Guidelines and changes some previous recommendations following new evidence.
For the first time there is a clear definition of when to start the clock for the 90 minute target to treat patients with percutaneous coronary intervention (PCI). The clock should start at the time of ST-segment elevation myocardial infarction (STEMI) diagnosis by electrocardiogram (ECG).
“Until now there was confusion over whether the clock starts when the patient has the first symptoms, when he or she calls the emergency services, when the ambulance arrives on the scene, or when the patient arrives at the hospital,” said Task Force Chairperson Prof Stefan James (Sweden). “We don’t know if the patient is suffering from STEMI until the ECG so this is a sensible starting point and the vessel should be opened within 90 minutes from then.”
The vague term door-to-balloon has been removed from the guidelines and first medical contact (FMC) is defined as the time point when the patient is initially assessed by a physician, paramedic or nurse who obtains and interprets the ECG. “Door-to-balloon is no longer a useful term,” said Task Force Chairperson Dr Borja Ibanez (Spain). “Treatment used to be initiated in the hospital but now it can start in the ambulance so the ‘door’ varies according to the situation.”
In cases where fibrinolysis is the reperfusion strategy, the maximum time delay from the diagnosis of STEMI to treatment has been shortened from 30 minutes in 2012 to 10 minutes in 2017.
Complete revascularization was not recommended in the 2012 document which said that only infarct-related arteries should be treated. Today’s guidelines state that complete revascularization should be considered, with non-infarct-related arteries treated during the index procedure or another time point before discharge from hospital.
Thrombus aspiration is no longer recommended, based on two large trials in more than 15 000 patients. Also not recommended is deferred stenting, which involved opening the artery and waiting 48 hours to implant a stent. Regarding PCI, the use of drug eluting stents instead of bare metal stents has gained a stronger recommendation as has the use of radial, instead of femoral, arterial access.
When it comes to medications, the authors state that dual antiplatelet therapy extension beyond 12 months in selected patients may be considered. Bivalirudin has been downgraded from class I to IIa, and enoxaparin upgraded from class IIb to IIa. Cangrelor, which was not mentioned in the 2012 document, has been recommended as an option in certain patients. Also new is a recommendation for additional lipid lowering therapy in patients with high cholesterol despite taking the maximum dose of statins.
The cut off for administering oxygen therapy has been lowered from less than 95% to less than 90% arterial oxygen saturation. Left and right bundle branch block are now considered equal for recommending urgent angiography when patients have ischemic symptoms.
A chapter has been added on myocardial infarction with nonobstructive coronary arteries (MINOCA), which comprises up to 14% of STEMI patients and demands additional diagnostic tests and tailored therapy which may differ from typical STEMI.
ESC http://tinyurl.com/y8nhmu38