Posts Tagged ‘stroke’

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AliveCor receives FDA clearance on its mobile heart monitor

AliveCor receives FDA clearance on its mobile heart monitor

AliveCor, Inc. announced today at the start of the 4th annual mHealth Summit in Washington, D.C. that the company received FDA 510(k) clearance on its mobile Heart Monitor as well as CE Mark conformity. This clinical-quality, low-cost mobile ECG heart monitor, compatible with the iPhone® 4 and 4S, enables doctors to evaluate patient heart health easily, quickly and remotely.

“Our goal is to make health care cheaper, easier and more readily available without losing quality of care”

Clinical studies of the device indicate that a high-quality single-channel ECG can be rapidly and simply recorded using an iPhone with the AliveCor application and device, to accurately screen for cardiac arrhythmias including atrial fibrillation. Atrial fibrillation is the most commonly occurring arrhythmia and carries a five-fold increased risk of stroke.

Additionally, AliveCor’s founder, Dr. David Albert, and co-founders Bruce Satchwell and Kim Barnett were granted U.S. Patent No. 8,301,232 for the device and technology. The three colleagues began working on the heart-monitoring device in 2008.

“We believe that mobile ECGs and other breakthroughs in mobile health can significantly change the way medicine is delivered,” Dr. Albert said.

AliveCor’s Heart Monitor is initially intended for use by licensed medical professionals to record, display, store, transfer, and evaluate single-channel electrocardiogram (ECG) rhythms.

The rhythm strips can be of any duration, and are stored on the iPhone and securely in the cloud for later analysis, sharing and printing through AliveCor’s secure website. The ECG data is sent wirelessly from the Heart Monitor via AliveCor’s low-power, proprietary communication protocol, and requires no pairing between the iPhone and the device.

The device incorporates electrodes into a case that snaps onto the back of an iPhone 4 or 4S. The Heart Monitor is used by launching the corresponding AliveECG app on the iPhone, holding the device in a relaxed state, and pressing fingers from each hand to each of the two appropriate electrodes on the device. The device can also be used to obtain an ECG by placing it on the chest.

“Our goal is to make health care cheaper, easier and more readily available without losing quality of care,” said AliveCor President and CEO Judy Wade. “Our aspirations are significant; we’re out to make a real difference.”

AliveCor’s Heart Monitor is available for pre-sale to medical professionals in the U.S., beginning today, through the company website, www.alivecor.com. The cost is $199. AliveCor plans to begin selling the Heart Monitor in Europe in early 2013.

Source : http://www.news-medical.net/news/20121203/AliveCor-receives-FDA-clearance-on-its-mobile-heart-monitor.aspx

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NICE recommends Bispectral Index EEG-based monitor for measuring depth of anaesthesia

NICE recommends Bispectral Index EEG-based monitor for measuring depth of anaesthesia

Covidien, a leading global provider of healthcare products and recognized innovator in patient monitoring and respiratory care devices, today announced that the UK-based National Institute for Health and Clinical Excellence (NICE) recommends the use of electroencephalography (EEG)-based monitors, specifically the Bispectral Index (BIS™) monitor, as an option for measuring depth of anaesthesia.

“The NICE assessment and recommendations provide clear guidance to anaesthesia professionals regarding the use of depth of anaesthesia monitoring that will greatly improve patient care and safety for individuals at higher risk for adverse reactions to general anaesthesia”

The recommendation specifies that the BIS monitor should be used with all patients receiving total intravenous anaesthesia and during any type of general anaesthesia with patients considered at high risk of adverse outcomes. This includes patients at high risk of unintended awareness and patients at high risk of excessively deep anaesthesia. The Covidien BIS Brain Monitoring System helps clinicians assess patient consciousness levels through electrical activity in the brain.

The NICE guidance specifically recommends the BIS system as an option in the care of patients at high risk for unintended awareness (consciousness) or excessively deep anaesthesia levels during surgery. Both can lead to serious short- and long-term health risks, including post-traumatic stress disorder, heart attack, and stroke and in older patients, cognitive dysfunction or “brain fog.”

Patients at high risk for unintended awareness include older patients as well as those with morbid obesity, poor cardiovascular function, presence of two or more chronic diseases, high opiate or alcohol use, intravenous anaesthesia techniques and certain types of surgical procedures.

The recommendation for BIS monitoring as an option in patients receiving total intravenous anaesthesia was made because it is cost effective and because it is not possible to measure anaesthetic concentration in these patients.

“The NICE assessment and recommendations provide clear guidance to anaesthesia professionals regarding the use of depth of anaesthesia monitoring that will greatly improve patient care and safety for individuals at higher risk for adverse reactions to general anaesthesia,” said Scott Kelley, M.D., Chief Medical Officer, Respiratory and Monitoring Solutions, Covidien. “With BIS brain monitoring technology, anaesthetists, in combination with their other standard practices, can accurately determine consciousness and tailor anaesthesia dosing to ensure optimal patient experience and minimize risks.”

The NICE Diagnostics Guidance is based on extensive clinical evidence and an assessment report prepared by the University of Southampton’s Southampton Health Technology Assessment Centre and input from a number of professional organisations and device manufacturers. Other brain monitoring technologies assessed as part of the clinical research include the GE Healthcare E-Entropy and Schiller Narcotrend-Compact M.

Source : http://www.news-medical.net/news/20121123/NICE-recommends-Bispectral-Index-EEG-based-monitor-for-measuring-depth-of-anaesthesia.aspx

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Tirofiban effectively prevents strokes in high risk patients

Tirofiban effectively prevents strokes in high risk patients

Scientists may have discovered a new way to prevent strokes in high risk patients, according to research from the University of Warwick and University Hospitals Coventry and Warwickshire (UHCW).

Work by a new research group, led by Professor Donald Singer, Professor of Therapeutics at Warwick Medical School and Professor Chris Imray from UHCW, has now been published in US journal Stroke.

The group is using ultrasound scanning to look at patients with carotid artery disease, one of the major causes of stroke. Clots can form on diseased carotid arteries in the neck. Small parts of these clots can released to form microemboli, which can travel to block key brain arteries and lead to weakness, disturbed speech, loss of vision and other serious stroke syndromes. Standard anti-platelet drugs such as aspirin may not prevent the formation of harmful microemboli.

The scanning process can be used to find patients at very high risk of stroke because microemboli have formed despite prior anti-platelet drugs. Using scanning, the team has found that tirofiban, another anti-platelet drug designed to inhibit the formation of blood clots, can suppress microemboli where previous treatment such as aspirin has been ineffective. In their study, tirofiban was more effective than other ‘rescue’ treatment.

Professor Singer said: “These findings show that the choice of rescue medicine is very important when carotid patients develop microemboli despite previous treatment with powerful anti-platelet drugs such as aspirin. We now need to go on to further studies of anti-microemboli rescue treatments, to aim for the right balance between protection and risk for our patients.”

Professor Imray said: “These findings show the importance of ultrasound testing for micro-emboli in carotid disease patients. These biomarkers of high stroke risk cannot be predicted just from assessing the severity of risk factors such as smoking history, cholesterol and blood pressure.”

Source : http://www.news-medical.net/news/20121122/Tirofiban-effectively-prevents-strokes-in-high-risk-patients.aspx

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Tirofiban effectively prevents strokes in high risk patients

Tirofiban effectively prevents strokes in high risk patients

Scientists may have discovered a new way to prevent strokes in high risk patients, according to research from the University of Warwick and University Hospitals Coventry and Warwickshire (UHCW).

Work by a new research group, led by Professor Donald Singer, Professor of Therapeutics at Warwick Medical School and Professor Chris Imray from UHCW, has now been published in US journal Stroke.

The group is using ultrasound scanning to look at patients with carotid artery disease, one of the major causes of stroke. Clots can form on diseased carotid arteries in the neck. Small parts of these clots can released to form microemboli, which can travel to block key brain arteries and lead to weakness, disturbed speech, loss of vision and other serious stroke syndromes. Standard anti-platelet drugs such as aspirin may not prevent the formation of harmful microemboli.

The scanning process can be used to find patients at very high risk of stroke because microemboli have formed despite prior anti-platelet drugs. Using scanning, the team has found that tirofiban, another anti-platelet drug designed to inhibit the formation of blood clots, can suppress microemboli where previous treatment such as aspirin has been ineffective. In their study, tirofiban was more effective than other ‘rescue’ treatment.

Professor Singer said: “These findings show that the choice of rescue medicine is very important when carotid patients develop microemboli despite previous treatment with powerful anti-platelet drugs such as aspirin. We now need to go on to further studies of anti-microemboli rescue treatments, to aim for the right balance between protection and risk for our patients.”

Professor Imray said: “These findings show the importance of ultrasound testing for micro-emboli in carotid disease patients. These biomarkers of high stroke risk cannot be predicted just from assessing the severity of risk factors such as smoking history, cholesterol and blood pressure.”

Source : http://www.news-medical.net/news/20121122/Tirofiban-effectively-prevents-strokes-in-high-risk-patients.aspx

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NICE recommends Bispectral Index EEG-based monitor for measuring depth of anaesthesia

NICE recommends Bispectral Index EEG-based monitor for measuring depth of anaesthesia

Covidien, a leading global provider of healthcare products and recognized innovator in patient monitoring and respiratory care devices, today announced that the UK-based National Institute for Health and Clinical Excellence (NICE) recommends the use of electroencephalography (EEG)-based monitors, specifically the Bispectral Index (BIS™) monitor, as an option for measuring depth of anaesthesia.

“The NICE assessment and recommendations provide clear guidance to anaesthesia professionals regarding the use of depth of anaesthesia monitoring that will greatly improve patient care and safety for individuals at higher risk for adverse reactions to general anaesthesia”

The recommendation specifies that the BIS monitor should be used with all patients receiving total intravenous anaesthesia and during any type of general anaesthesia with patients considered at high risk of adverse outcomes. This includes patients at high risk of unintended awareness and patients at high risk of excessively deep anaesthesia. The Covidien BIS Brain Monitoring System helps clinicians assess patient consciousness levels through electrical activity in the brain.

The NICE guidance specifically recommends the BIS system as an option in the care of patients at high risk for unintended awareness (consciousness) or excessively deep anaesthesia levels during surgery. Both can lead to serious short- and long-term health risks, including post-traumatic stress disorder, heart attack, and stroke and in older patients, cognitive dysfunction or “brain fog.”

Patients at high risk for unintended awareness include older patients as well as those with morbid obesity, poor cardiovascular function, presence of two or more chronic diseases, high opiate or alcohol use, intravenous anaesthesia techniques and certain types of surgical procedures.

The recommendation for BIS monitoring as an option in patients receiving total intravenous anaesthesia was made because it is cost effective and because it is not possible to measure anaesthetic concentration in these patients.

“The NICE assessment and recommendations provide clear guidance to anaesthesia professionals regarding the use of depth of anaesthesia monitoring that will greatly improve patient care and safety for individuals at higher risk for adverse reactions to general anaesthesia,” said Scott Kelley, M.D., Chief Medical Officer, Respiratory and Monitoring Solutions, Covidien. “With BIS brain monitoring technology, anaesthetists, in combination with their other standard practices, can accurately determine consciousness and tailor anaesthesia dosing to ensure optimal patient experience and minimize risks.”

The NICE Diagnostics Guidance is based on extensive clinical evidence and an assessment report prepared by the University of Southampton’s Southampton Health Technology Assessment Centre and input from a number of professional organisations and device manufacturers. Other brain monitoring technologies assessed as part of the clinical research include the GE Healthcare E-Entropy and Schiller Narcotrend-Compact M.

Source : http://www.news-medical.net/news/20121123/NICE-recommends-Bispectral-Index-EEG-based-monitor-for-measuring-depth-of-anaesthesia.aspx

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Tirofiban effectively prevents strokes in high risk patients

Tirofiban effectively prevents strokes in high risk patients

Scientists may have discovered a new way to prevent strokes in high risk patients, according to research from the University of Warwick and University Hospitals Coventry and Warwickshire (UHCW).

Work by a new research group, led by Professor Donald Singer, Professor of Therapeutics at Warwick Medical School and Professor Chris Imray from UHCW, has now been published in US journal Stroke.

The group is using ultrasound scanning to look at patients with carotid artery disease, one of the major causes of stroke. Clots can form on diseased carotid arteries in the neck. Small parts of these clots can released to form microemboli, which can travel to block key brain arteries and lead to weakness, disturbed speech, loss of vision and other serious stroke syndromes. Standard anti-platelet drugs such as aspirin may not prevent the formation of harmful microemboli.

The scanning process can be used to find patients at very high risk of stroke because microemboli have formed despite prior anti-platelet drugs. Using scanning, the team has found that tirofiban, another anti-platelet drug designed to inhibit the formation of blood clots, can suppress microemboli where previous treatment such as aspirin has been ineffective. In their study, tirofiban was more effective than other ‘rescue’ treatment.

Professor Singer said: “These findings show that the choice of rescue medicine is very important when carotid patients develop microemboli despite previous treatment with powerful anti-platelet drugs such as aspirin. We now need to go on to further studies of anti-microemboli rescue treatments, to aim for the right balance between protection and risk for our patients.”

Professor Imray said: “These findings show the importance of ultrasound testing for micro-emboli in carotid disease patients. These biomarkers of high stroke risk cannot be predicted just from assessing the severity of risk factors such as smoking history, cholesterol and blood pressure.”

Source : http://www.news-medical.net/news/20121122/Tirofiban-effectively-prevents-strokes-in-high-risk-patients.aspx

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Turning Thoughts into Action: New Advance in Brain-Controlled Computer Cursors

Turning Thoughts into Action: New Advance in Brain-Controlled Computer Cursors

Turning Thoughts into Action: New Advance in Brain-Controlled Computer Cursors

Stanford researchers have designed the fastest, most accurate algorithm yet for brain-implantable prosthetic systems that can help disabled people maneuver computer cursors with their thoughts. The algorithm’s speed, accuracy and natural movement approach those of a real arm, doubling performance of existing algorithms.

By Kelly Servick

When a paralyzed person imagines moving a limb, cells in the part of the brain that controls movement still activate as if trying to make the immobile limb work again. Despite neurological injury or disease that has severed the pathway between brain and muscle, the region where the signals originate remains intact and functional.

In recent years, neuroscientists and neuroengineers working in prosthetics have begun to develop brain-implantable sensors that can measure signals from individual neurons, and after passing those signals through a mathematical decode algorithm, can use them to control computer cursors with thoughts. The work is part of a field known as neural prosthetics.

A team of Stanford researchers have now developed an algorithm, known as ReFIT, that vastly improves the speed and accuracy of neural prosthetics that control computer cursors. The results are to be published November 18 in the journal Nature Neuroscience in a paper by Krishna Shenoy, a professor of electrical engineering, bioengineering and neurobiology at Stanford, and a team led by research associate Dr. Vikash Gilja and bioengineering doctoral candidate Paul Nuyujukian.

Vikash Gilja, Krishna Shenoy and Paul Nuyujukian (left to right) discuss results of their new algorithm that greatly improves performance of a computer cursor controlled by thoughts conveyed through a sensor implanted in the brain. The new algorithm approaches the speed, accuracy and natural motion of real arm. Trials in paralyzed humans have been approved by the FDA. Photo: Joel Simon.

In side-by-side demonstrations with rhesus monkeys, cursors controlled by the ReFIT algorithm doubled the performance of existing systems and approached performance of the real arm. Better yet, more than four years after implantation, the new system is still going strong, while previous systems have seen a steady decline in performance over time.

“These findings could lead to greatly improved prosthetic system performance and robustness in paralyzed people, which we are actively pursuing as part of the FDA Phase-I BrainGate2 clinical trial here at Stanford,” said Shenoy.

Sensing mental movement in real time

The system relies on a silicon chip implanted into the brain, which records “action potentials” in neural activity from an array of electrode sensors and sends data to a computer. The frequency with which action potentials are generated provides the computer key information about the direction and speed of the user’s intended movement.

The ReFIT algorithm that decodes these signals represents a departure from earlier models. In most neural prosthetics research, scientists have recorded brain activity while the subject moves or imagines moving an arm, analyzing the data after the fact. “Quite a bit of the work in neural prosthetics has focused on this sort of offline reconstruction,” said Gilja, the first author of the paper.

On each side of the screen, a monkey moves a cursor with its thoughts, using the cursor to make contact with the colored ball. On the left, the monkey’s thoughts are decoded with the use of a mathematical algorithm known as Velocity Kalman Filter. On the right, the monkey’s thoughts are decoded with a new algorithm developed at Stanford, known as ReFIT, with better results. The ReFIT system helps the monkey to select 21 targets in 21 seconds, as opposed to just 10 with the older system in the same time. Video courtesy of Vikash Gilja, Stanford University School of Engineering.

The Stanford team wanted to understand how the system worked “online,” under closed-loop control conditions in which the computer analyzes and implements visual feedback gathered in real time as the monkey neurally controls the cursor to toward an onscreen target.

The system is able to make adjustments on the fly when while guiding the cursor to a target, just as a hand and eye would work in tandem to move a mouse-cursor onto an icon on a computer desktop. If the cursor were straying too far to the left, for instance, the user likely adjusts their imagined movements to redirect the cursor to the right. The team designed the system to learn from the user’s corrective movements, allowing the cursor to move more precisely than it could in earlier prosthetics.

To test the new system, the team gave monkeys the task of mentally directing a cursor to a target — an onscreen dot — and holding the cursor there for half a second. ReFIT performed vastly better than previous technology in terms of both speed and accuracy. The path of the cursor from the starting point to the target was straighter and it reached the target twice as quickly as earlier systems, achieving 75 to 85 percent of the speed of real arms.

“This paper reports very exciting innovations in closed-loop decoding for brain-machine interfaces. These innovations should lead to a significant boost in the control of neuroprosthetic devices and increase the clinical viability of this technology,” said Jose Carmena, associate professor of electrical engineering and neuroscience at the University of California Berkeley.

A smarter algorithm

Critical to ReFIT’s time-to-target improvement was its superior ability to stop the cursor. While the old model’s cursor reached the target almost as fast as ReFIT, it often overshot the destination, requiring additional time and multiple passes to hold the target.

The key to this efficiency was in the step-by-step calculation that transforms electrical signals from the brain into movements of the cursor onscreen. The team had a unique way of “training” the algorithm about movement. When the monkey used his real arm to move the cursor, the computer used signals from the implant to match the arm movements with neural activity. Next, the monkey simply thought about moving the cursor, and the computer translated that neural activity into onscreen movement of the cursor. The team then used the monkey’s brain activity to refine their algorithm, increasing its accuracy.

The team introduced a second innovation in the way ReFIT encodes information about the position and velocity of the cursor. Gilja said that previous algorithms could interpret neural signals about either the cursor’s position or its velocity, but not both at once. ReFIT can do both, resulting in faster, cleaner movements of the cursor

An engineering eye

Early research in neural prosthetics had the goal of understanding the brain and its systems more thoroughly, Gilja said, but he and his team wanted to build on this approach by taking a more pragmatic engineering perspective. “The core engineering goal is to achieve highest possible performance and robustness for a potential clinical device, ” he said.

To create such a responsive system, the team decided to abandon one of the traditional methods in neural prosthetics. Much of the existing research in this field has focused on differentiating among individual neurons in the brain.

Importantly, such a detailed approach has allowed neuroscientists to create a detailed understanding of the individual neurons that control arm movement.

The individual neuron approach has its drawbacks, Gilja said. “From an engineering perspective, the process of isolating single neurons is difficult, due to minute physical movements between the electrode and nearby neurons, making it error-prone,” he said. ReFIT focuses on small groups of neurons instead of single neurons.

These diagrams trace the accuracy of various trial scenarios of the ReFIT algorithm developed at Stanford. On the left is a a real arm. In the middle, the monkey uses ReFIT and on the right the monkey uses the old algorithm. Note the tendency of the old algorithm to overshoot the target and, conversely, how the ReFIT traces closely resemble those of the real arm.

By abandoning the single-neuron approach, the team also reaped a surprising benefit: performance longevity. Neural implant systems that are fine-tuned to specific neurons degrade over time. It is a common belief in the field that after six months to a year, they can no longer accurately interpret the brain’s intended movement. Gilja said the Stanford system is working very well more than four years later.

“Despite great progress in brain-computer interfaces to control the movement of devices such as prosthetic limbs, we’ve been left so far with halting, jerky, Etch-a-Sketch-like movements. Dr. Shenoy’s study is a big step toward clinically useful brain-machine technology that have faster, smoother, more natural movements,” said James Gnadt, PhD, a program director in Systems and Cognitive Neuroscience at the National Institute of Neurological Disorders and Stroke, part of the National Institutes of Health.

For the time being, the team has been focused on improving cursor movement rather than the creation of robotic limbs, but that is not out of the question, Gilja said. Near term, precise, accurate control of a cursor is a simplified task with enormous value for paralyzed people.

“We think we have a good chance of giving them something very useful,” he said. The team is now translating these innovations to paralyzed people as part of a clinical trial.

This research was funded by the Christopher and Dana Reeve Paralysis Foundation; NSF, NDSEG, and SGF Graduate Fellowships; DARPA (“Revolutionizing Prosthetics” and “REPAIR”); and NIH (NINDS-CRCNS and Director’s Pioneer Award).

Other contributing researchers include Cynthia Chestek, John Cunningham, and Byron Yu, Joline Fan, Mark Churchland, Matthew Kaufman, Jonathan Kao, and Stephen Ryu.

Neural prostheses translate neural activity from the brain into control signals for guiding prosthetic devices, such as computer cursors and robotic limbs, and thus offer individuals with disabilities greater interaction with the world. However, relatively low performance remains a critical barrier to successful clinical translation; current neural prostheses are considerably slower, with less accurate control, than the native arm. Here we present a new control algorithm, the recalibrated feedback intention–trained Kalman filter (ReFIT-KF) that incorporates assumptions about the nature of closed-loop neural prosthetic control. When tested in rhesus monkeys implanted with motor cortical electrode arrays, the ReFIT-KF algorithm outperformed existing neural prosthetic algorithms in all measured domains and halved target acquisition time. This control algorithm permits sustained, uninterrupted use for hours and generalizes to more challenging tasks without retraining. Using this algorithm, we demonstrate repeatable high performance for years after implantation in two monkeys, thereby increasing the clinical viability of neural prostheses.

For the millions of individuals annually who are victims of traumatic brain injury, neurodegenerative disease, stroke, or other neurological disease, paralysis may be a devastating consequence. Scientists in the field of neural prostheses have for years been attempting to address limb paralysis by developing implantable brain sensors that translate thoughts to actions such as computer cursor movement. Perfecting the computer algorithm for this translation has proven a challenge. Recently, however, researchers at Stanford University have designed an algorithm, known as ReFIT, that vastly improves the speed and accuracy of neural prostheses that control computer cursors.

We have previously covered potential applications for brain-implantable devices that link neural signals to computerized features. The advantage of the ReFIT technology is that it allows the system to make immediate adjustments while guiding the cursor to a target, just as a hand and eye work together to move a mouse-cursor onto an icon on a computer desktop.

According to the press release:

The system relies on a silicon chip implanted into the brain, which records “action potentials” in neural activity from an array of electrode sensors and sends data to a computer. The frequency with which action potentials are generated provides the computer key information about the direction and speed of the user’s intended movement….

In side-by-side demonstrations with rhesus monkeys, cursors controlled by the ReFIT algorithm doubled the performance of existing systems and approached performance of the real arm. Better yet, more than four years after implantation, the new system is still going strong, while previous systems have seen a steady decline in performance over time.

“These findings could lead to greatly improved prosthetic system performance and robustness in paralyzed people, which we are actively pursuing as part of the FDA Phase-I BrainGate2 clinical trial here at Stanford,” said [Krishna] Shenoy.

The efficiency of cursor movement ranged from between 75-85 percent of the speed of real arms – a remarkable advancement.

source : http://engineering.stanford.edu/research-profile/leap-forward-brain-controlled-computer-cursors

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St. Jude Medical Study Demonstrates Effectiveness of Implantable Device Monitoring in Predicting Stroke

St. Jude Medical Study Demonstrates Effectiveness of Implantable Device Monitoring in Predicting Stroke

St. Jude Medical Study Demonstrates Effectiveness of Implantable Device Monitoring in Predicting Stroke

St. Jude Medical Announces Results of ASSERT Study Demonstrating Effectiveness of Implantable Device Monitoring in Predicting Stroke

ST. PAUL, Minn., Nov 15, 2010 (BUSINESS WIRE) –

St. Jude Medical, Inc. (NYSE:STJ), a global medical device company, today announced the results of the ASymptomatic AF and Stroke Evaluation in Pacemaker Patients and the AF Reduction Atrial Pacing Trial (ASSERT), a St. Jude Medical sponsored trial conducted by the Population Health Research Institute of McMaster University and Hamilton Health Sciences in Hamilton, Canada. The trial demonstrated that pacemaker patients without history of atrial tachycardia (AT) or atrial fibrillation (AF) who have device-detected arrhythmias are approximately 2.5 times more likely to have a stroke than patients who don’t have device-detected arrhythmias.

The results of the trial were presented today by Dr. Jeff S. Healey, principal investigator for the arrhythmias program at the Population Health Research Institute, during the “Clinical Science: Special Reports” session at the American Heart Association Scientific Sessions 2010 in Chicago.

“These results are significant because they demonstrate that even brief, asymptomatic AF episodes can cause a stroke, and that the proportion of strokes that are associated with atrial arrhythmias is much higher than previously thought,” said Dr. Healey. “This trial shows that by using the information already available in implantable pacemakers and defibrillators, physicians can identify patients at risk for stroke, earlier than would otherwise be the case, even before they experience arrhythmia symptoms.”

ASSERT studied 2,580 pacemaker patients over the age of 65 with hypertension and no history of AF. The trial was a cohort study designed to determine whether the detection of arrhythmias using pacemaker-based diagnostics predicts an increased risk of stroke in elderly, hypertensive patients without any history of AF. Atrial fibrillation had previously been linked to an increased risk of stroke but it was not clear that brief, often asymptomatic AF episodes are associated with an increased risk for stroke as well.

Technologies such as the AT/AF diagnostic data and alerts available in St. Jude Medical implantable devices, including the Accent(TM) pacemaker and Fortify(TM) ICD (implantable cardioverter defibrillator), via the Merlin.net remote monitoring system, allow physicians and patients to be notified whenever a patient experiences significant atrial arrhythmias – abnormal heartbeats in the heart’s upper chambers – such as AT or AF.

“These results further demonstrate the value of the arrhythmia monitoring algorithms and alerts offered in St. Jude Medical pacemakers and implantable defibrillators,” said Dr. Mark Carlson, chief medical officer and senior vice president of research and clinical affairs for the St. Jude Medical Cardiac Rhythm Management Division. “This study reaffirms our commitment to providing physicians with the clinically relevant information that allows them to deliver more timely and effective care.”

Atrial fibrillation (AF) is a chaotic, uncontrolled heart rhythm. It occurs when the upper chambers of the heart (atria) contract rapidly and irregularly – from 350 to 600 times per minute compared to a normal heart rhythm of 60 to 100 times per minute. AF is known to be a common risk factor for, and cause of, stroke. Because the atria contract so rapidly and irregularly during AF, the heart cannot beat effectively and blood is not pumped completely out of the atria. Blood that pools in the atria may clot and, if the clot moves to an artery in the brain, stroke may occur. Studies show that AF increases the risk of stroke five-fold. The risk for stroke related to AF increases with age, and AF potentially leads to a range of other debilitating symptoms as well.

About St. Jude Medical

St. Jude Medical develops medical technology and services that focus on putting more control into the hands of those who treat cardiac, neurological and chronic pain patients worldwide. The company is dedicated to advancing the practice of medicine by reducing risk wherever possible and contributing to successful outcomes for every patient. St. Jude Medical is headquartered in St. Paul, Minn. and has four major focus areas that include: cardiac rhythm management, atrial fibrillation, cardiovascular and neuromodulation. For more information, please visit sjm.com.

Forward-Looking Statements

This news release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 that involve risks and uncertainties. Such forward-looking statements include the expectations, plans and prospects for the Company, including potential clinical successes, anticipated regulatory approvals and future product launches, and projected revenues, margins, earnings and market shares. The statements made by the Company are based upon management’s current expectations and are subject to certain risks and uncertainties that could cause actual results to differ materially from those described in the forward-looking statements. These risks and uncertainties include market conditions and other factors beyond the Company’s control and the risk factors and other cautionary statements described in the Company’s filings with the SEC, including those described in the Risk Factors and Cautionary Statements sections of the Company’s Quarterly Report on Form 10-Q for the fiscal quarter ended October 2, 2010. The Company does not intend to update these statements and undertakes no duty to any person to provide any such update under any circumstance.

It is common clinical knowledge that, given a patient who comes in with Atrial Fibrilation (AFib), you must either anticoagulate the patient for a sufficient period or take a look inside with an echocardiogram to look for clots before trying to electrically cardiovert them. The reason for this is that a clot sitting in the atrium could be dislodged and head straight for the brain, causing an embolic stroke.

According to a St. Jude Medical study, this risk of stroke holds true even if the episode of AFib or Atrial Tachycardia (ATach) is only a few seconds long and is completely asymptomatic. The study used the detection algorithms built into the patients’ pacemakers. The data from St. Jude devices was communicated to the Merlin.net monitoring system to record even brief episodes of AFib and ATach. The study, the ASymptomatic AF and Stroke Evaluation in Pacemaker Patients and the AF Reduction Atrial Pacing Trial (ASSERT), showed a 2.5-fold increase of strokes in patients who had device-detected arrhythmias compared to those who had none.

We’re in a time now when a tech-savvy doctor can get a message on his or her iPad from a pacemaker saying that Mr. Smith has had several brief episodes of AFib and ATach this week, prompting the doc to schedule an appointment (electronically, of course) to have Mr. Smith come to the office and discuss ways to reduce his stroke risk.

source : http://investors.sjm.com/phoenix.zhtml?c=73836&p=irol-newsArticle&ID=1496331

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NIH-funded scientists develop new treatment to combat autoimmune disorders in mouse model

NIH-funded scientists develop new treatment to combat autoimmune disorders in mouse model

In a mouse model of multiple sclerosis (MS), researchers funded by the National Institutes of Health have developed innovative technology to selectively inhibit the part of the immune system responsible for attacking myelin-the insulating material that encases nerve fibers and facilitates electrical communication between brain cells.

Autoimmune disorders occur when T-cells-a type of white blood cell within the immune system-mistake the body’s own tissues for a foreign substance and attack them. Current treatment for autoimmune disorders involves the use of immunosuppressant drugs which tamp down the overall activity of the immune system. However, these medications leave patients susceptible to infections and increase their risk of cancer as the immune system’s normal ability to identify and destroy aberrant cells within the body is compromised.

Supported by the National Institute of Biomedical Imaging and Bioengineering (NIBIB) at NIH, Drs. Stephen Miller and Lonnie Shea at Northwestern University, Evanston, teamed up with researchers at the University of Sydney, and the Myelin Repair Foundation in Saratoga, Calif. to come up with a novel way of repressing only the part of the immune system that causes autoimmune disorders while leaving the rest of the system intact.

The new research takes advantage of a natural safeguard employed by the body to prevent autoreactive T-cells-which recognize and have the potential to attack the body’s healthy tissues-from becoming active. They report their results in the Nov. 18 online edition of Nature Biotechnology.

“We’re trying to do something that interfaces with the natural processes in the body,” said Shea. “The body has natural mechanisms for shutting down an immune response that is inappropriate, and we’re really just looking to tap into that.”

One of these natural mechanisms involves the ongoing clearance of apoptotic, or dying, cells from the body. When a cell dies, it releases chemicals that attract specific cells of the immune system called macrophages. These macrophages gobble up the dying cell and deliver it to the spleen where it presents self-antigens-tiny portions of proteins from the dying cell-to a pool of T-cells. In order to prevent autoreactive T-cells from being activated, macrophages initiate the repression of any T-cells capable of binding to the self-antigens.

Dr. Miller was the first to demonstrate that by coupling a specific self-antigen such as myelin to apoptotic cells, one could tap into this natural mechanism to suppress T-cells that would normally attack the myelin. The lab spent decades demonstrating that they could generate antigen-specific immune suppression in various animal models of autoimmune diseases. Recently, they initiated a preliminary clinical trial with collaborators in Germany to test the safety of injecting the antigen-bound apoptotic cells into patients with MS. While the trial successfully demonstrated that the injections were safe, it also highlighted a key problem with using cells as a vehicle for antigen delivery:

“Cellular therapy is extremely expensive as it needs to be carried out in a large medical center that has the capability to isolate patient’s white blood cells under sterile conditions and to re-infuse those antigen-coupled cells back into the patients,” said Miller. “It’s a costly, difficult, and time-consuming procedure.”

Thus began a collaboration with Dr. Shea, a bioengineer at Northwestern University, to discuss the possibility of developing a surrogate for the apoptotic cells. After trying out various formulations, his lab successfully linked the desired antigens to microscopic, biodegradable particles which they predicted would be taken up by circulating macrophages similar to apoptotic cells.

Much to their amazement, when tested by the Miller lab, the antigen-bound particles were just as good, if not better, at inducing T-cell tolerance in animal models of autoimmune disorders.

Using their myelin-bound particles, the researchers were able to both prevent the initiation of MS in their mouse model as well as inhibit its progression when injected immediately following the first sign of clinical symptoms.

The research team is now hoping to begin phase I clinical trials using this new technology. The material that makes up the particles has already been approved by the U.S. Food and Drug Administration and is currently used in resorbable sutures as well as in clinical trials to deliver anti-cancer agents. Miller believes that the proven safety record of these particles along with their ability to be easily produced using good manufacturing practices will make it easier to translate their discovery into clinical use.

“I think we’ve come up with a very potent way to induce tolerance that can be easily translated into clinical practice. We’re doing everything we can now to take this forward,” said Miller.

In addition to its potential use for the treatment of MS, the researchers have shown in the lab that their therapy can induce tolerance for other autoimmune diseases such as type I diabetes and specific food allergies. They also speculate that transplant patients could benefit from the treatment which has the potential to retract the body’s natural immune response against a transplanted organ. Dr. Christine Kelley, NIBIB director of the Division of Science and Technology, points to the unique collaboration between scientists and engineers that made this advance a reality.

“This discovery is testimony to the importance of multidisciplinary research efforts in healthcare,” said Kelley. “The combined expertise of these immunology and bioengineering researchers has resulted in a valuable new perspective on treating autoimmune disorders.”

Source : http://www.news-medical.net/news/20121118/NIH-funded-scientists-develop-new-treatment-to-combat-autoimmune-disorders-in-mouse-model.aspx

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Researchers succeed in teaching computers how to identify commonalities in DNA sequences

Researchers succeed in teaching computers how to identify commonalities in DNA sequences

Johns Hopkins researchers have succeeded in teaching computers how to identify commonalities in DNA sequences known to regulate gene activity, and to then use those commonalities to predict other regulatory regions throughout the genome. The tool is expected to help scientists better understand disease risk and cell development.

The work was reported in two recent papers in Genome Research, published online on July 3 and Sept. 27.

“Our goal is to understand how regulatory information is encrypted and to learn which sequence variations contribute to medical risks,” says Andrew McCallion, Ph.D., associate professor of molecular and comparative pathobiology in the McKusick-Nathans Institute of Genetic Medicine at Hopkins. “We give data to a computer and ‘teach it’ to distinguish between data that has no biological value versus data that has this or that biological value. It then establishes a set of rules, which allows it to look at new sets of data and apply what it learned. We’re basically sending our computers to school.”

These state-of-the-art “machine learning” techniques were developed by Michael Beer, Ph.D., assistant professor of biomedical engineering at the Johns Hopkins School of Medicine, and by Ivan Ovcharenko, Ph.D., at the National Center for Biotechnology Information. The researchers began both studies by creating “training sets” for their computers to “learn” from. These training sets were lists of DNA sequences taken from regions of the genome, called enhancers, that are known to increase the activity of particular genes in particular cells.

For the first of their studies, McCallion’s team created a training set of enhancer sequences specific to a particular region of the brain by compiling a list of 211 published sequences that had been shown, by various studies in mice and zebrafish, to be active in the development or function of that part of the brain.

For a second study, the team generated a training set through experiments of their own. They began with a purified population of mouse melanocytes, which are the skin cells that produce the pigment melanin that gives color to skin and absorbs harmful UV rays from the sun. The researchers used a technique called ChIP-seq (pronounced “chip seek”) to collect and sequence all of the pieces of DNA that were bound in those cells by special enhancer-binding proteins, generating a list of about 2,500 presumed melanocyte enhancer sequences.

Once the researchers had these two training sets for their computers, one specific to the brain and another to melanocytes, the computers were able to distinguish the features of the training sequences from the features of all other sequences in the genome, and create rules that defined one set from the other. Applying those rules to the whole genome, the computers were able to discover thousands of probable brain or melanocyte enhancer sequences that fit the features of the training sets.

In the brain study, the computers identified 40,000 probable brain enhancer sequences; for melanocytes, 7,500. Randomly testing a subset of each batch of sequences, the scientists found that more than 85 percent of the predicted enhancer sequences enhanced gene activity in the brain or in melanocytes, as expected, verifying the predictive power of their approach.

The researchers say that, in addition to identifying specific DNA sequences that control the genetic activity of a particular organ or cell type, these studies contribute to our understanding of enhancers in general and have validated an experimental approach that can be applied to many other biological questions as well.

Source : http://www.news-medical.net/news/20121107/Researchers-succeed-in-teaching-computers-how-to-identify-commonalities-in-DNA-sequences.aspx

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