Archives: 5/2011

Cardiology / in the news...

Electromechanical Wave Imaging Non-Invasively Maps Electrical Activation of the Heart

by Wouter Stomp on May 10, 2011 • 12:53 am

h4gwmu5x Electromechanical Wave Imaging Non Invasively Maps Electrical Activation of the HeartResearchers from Columbia Engineering School developed a new method to non-invasively map the electrical activation of the heart. The technique, called Electromechanical Wave Imaging (EWI), uses ultrasound waves to detect very small deformations following the electrical activation of the heart. It can be incorporated into most current ultrasound scanners. Previously these measurements were possible only though invasive electrode contact, or non-invasively but indirectly, through complex mathematical modeling based on remote measurements. The study was published online in the May 9 issue of Proceedings of the National Academy of Sciences.

Using their EWI method, the Columbia Engineering team imaged the heart with ultrasound five times faster than standard echocardiography and mapped the local deformations of the heart with their images. The researchers then looked at small regions of the heart (just a few millimeters squared) and measured how much these regions were stretched or compressed every 2/1000s of a second. This enabled them to precisely identify at what time each region of the heart began to contract, a.k.a the electromechanical activation, in all four chambers of the heart. They compared their maps with the electrical activation sequence and found they were closely correlated, both at the natural rhythm of the heart and when the heart was artificially paced.
Arrhythmias occur when the normal electrical activation sequence in the heart is disrupted and their prevalence is expected to rise, as people live longer. In some cases, effective treatments exist. For example, a pacemaker can be surgically placed or a catheter can be brought into the cardiac chambers and used to burn diseased regions of the heart or pacing leads can be implanted in the heart to bypass the diseased conduction system and replace it by artificial electrical activation. But doctors can’t always tell where to ablate with a catheter or who will benefit from artificial electrical activation. EWI could help determine in advance which patients can benefit from these treatments or identify with more precision which regions of the heart should be ablated. It could also be used to adapt treatment parameters as the patient’s condition evolves.
“Since ultrasound is so safe, portable, and low cost,” added Dr. Konofagou, “we can imagine a future where most physicians can carry a portable ultrasound scanner the size of an iPhone and easily get a map of the activation of the heart during a routine visit.”
Her team has already begun to image patients with arrhythmias and compare their measurements with the gold standard of catheterization and non-contact electrode measurements. If this study is conclusive, they will then move to a larger clinical study.

Press release: Prof. Konofagou Develops Method To Diagnose Arrhythmias…

Cardiac Surgery / Cardiology

Medtronic’s Attain Ability Plus and Attain Ability Straight Left-Heart ICD Leads Now Available in US

by Gene Ostrovsky on May 9, 2011 • 12:48 pm

a3efsd Medtronics Attain Ability Plus and Attain Ability Straight Left Heart ICD Leads Now Available in USMedtronic has received FDA regulatory approval to market a pair of left ventricle cardiac resynchronization leads. The Attain Ability Plus and Attain Ability Straight left-heart leads are designed for better retention and easier placement.
From a Medtronic press release:

A pooled data analysis from several Medtronic left-heart lead studies for 1,307 patients presented today at Heart Rhythm 2011, the Heart Rhythm Society’s 32nd Annual Scientific Sessions, shows a CRT retention rate of 95 percent at 18 months for Medtronic’s Attain family of left heart leads. In this analysis, CRT retention rate was defined as 18-month survival rate from loss of CRT due to any left ventricle (LV) lead-related events that required operative intervention or termination of CRT. The observed events were LV lead dislodgement, phrenic nerve stimulation (PNS) (electrical stimulation of the nerve that facilitates breathing), and other LV lead failures such as elevated thresholds, loss of capture and lead fracture. Clinically acceptable performance was achieved in the majority of patients in this analysis using a variety of Medtronic left-ventricle leads to accommodate varying anatomies.
Attain Ability Plus enables physicians to reach and maintain the target vein, providing stability in medium-to-large venous anatomies, while Attain Ability Straight allows physicians to maneuver through small cardiac veins. These leads are part of the only portfolio of medical technology to incorporate NASA-developed insulation material that was previously evaluated for space applications, high-performance engines and harsh environments.
The design of the Attain Ability Plus and Attain Ability Straight left-heart leads, combined with their capacity to be delivered via the Attain Select II, a sub-selection catheter (in leads ³ 88 cm in length), assists physicians in placing the lead directly in difficult to reach locations in the heart.
According to clinical studies conducted on these leads, approximately 94 percent of physicians positively rated the ability to position the Attain Ability Plus lead to the desired cardiac veins, with a one-month complication-free rate of 98.5 percent. Additionally, 96.8 percent of physicians positively rated the handling of the Attain Ability Straight and the ability to maneuver it to the appropriate veins, with a low lead-dislodgement rate of 3.2 percent. Both left-heart leads offer multiple pacing vectors, which may help address PNS and help prevent the need to reposition the lead invasively.

More details: Medtronic Announces FDA Approval of Attain Ability® Plus and Attain Ability® Straight Left-Heart Leads for Cardiac Resynchronization Therapy (CRT) Devices

Neurology

Scientists Find That Computers With Schizophrenia Think Like Humans With Schizophrenia

by Scott Jung on May 9, 2011 • 10:05 am

q4523fwq Scientists Find That Computers With Schizophrenia Think Like Humans With SchizophreniaInfecting a virus on your computer is a surefire way to make it go crazy, but what happens if you afflict it with schizophrenia?
A team of researchers at the University of Texas did exactly that, attempting to investigate the mechanisms of schizophrenia in patients by modeling the illness on a computer. They found that elevated levels of dopamine, the neurotransmitter that controls the brain’s reward and pleasure center, could cause the brain to lose the normal ability to forget or ignore stimuli and become overwhelmed, unable to piece together a coherent story.
Their schizophrenic computer model consisted of a neural network called DISCERN that is able to learn natural language. They taught DISCERN a series of simple stories, which were stored into DISCERN’s memory in much the same way that the human brain stores information. For the schizophrenia model, the researchers trained DISCERN with the same stories a second time. However, they simulated an excess release of dopamine by increasing DISCERN’s rate of learning, analogous to making it stop forgetting information.
The result was that DISCERN would generate delusional, practically nonsensical stories: random disassociated sentences and jumps from first- to third-person. In one instance, DISCERN even claimed responsibility for a terrorist bombing!
While the results aren’t solid evidence for the mechanisms of schizophrenia, UT researchers are hopeful that the results could lead to the increased use of virtual models to study neurological disorders.
Article from UT-Austin: Scientists Afflict Computers with Schizophrenia to Better Understand the Human Brain…
Project website: Neural Network Models of Schizophrenic Language
Journal abstract: Using computational patients to evaluate illness mechanisms in schizophrenia
Image credit: Wellcome Images …

GI

Boston Sci’s Expect Aspiration Needle Now Available in U.S.

by Gene Ostrovsky on May 9, 2011 • 9:25 am

faeassse Boston Scis Expect Aspiration Needle Now Available in U.S.
Here’s a new device for submucosal and extramural gastrointestinal lesions sampling. Boston Scientific has announced U.S. and international launch of its Expect Endoscopic Ultrasound Aspiration Needle, a biopsy system designed to take tissue samples in organs adjacent to the gastrointestinal tract. The needle itself is made from a cobalt chromium allow, providing both strength and sharpness, and sports an etched pattern that makes it clearly visible under ultrasound.
zvvw23sd Boston Scis Expect Aspiration Needle Now Available in U.S.Some features from the product page:

Highly Visible Echogenic Pattern and Sharp Needle Grind

Echogenic pattern extends onto tip of needle to provide precise guidance to the target site and improved penetration of the lesion
Sheath provides smoother passage through the scope and controlled needle actuation

Ergonomic Handle

Controlled needle penetration with a shorter, wider design and slip-resistant grip
Sheath length and needle depth adjustment locks
Stylet remains coiled and in place for improved handling between needle passes
Secure attachment to the scope

Press release: Boston Scientific Begins U.S. and International Launch of Expect™ Endoscopic Ultrasound Aspiration Needle
Product page: Expect Endoscopic Ultrasound Aspiration Needle

Rehab

Snail Reader Vocalizes Printed Braille

by Gene Ostrovsky on May 9, 2011 • 9:25 am

t6q34fg Snail Reader Vocalizes Printed Braille
Yanko Design is featuring a product concept that can quickly and automatically read tactile Braille to the user. The donut shaped device, named Snail, would have a touch sensitive surface that can resolve individual bumps on paper and a speaker that would vocalize the text. Guide wheels along the outer edge of the sensor would help navigate the unit down the line of text to be read. Additionally, a built-in Bluetooth radio would be able to transmit the audio to an ear piece for less conspicuous use.
wpyje2u4 Snail Reader Vocalizes Printed Braille
More at Yanko Design…
(hat tip: Engadget)

Cardiac Surgery / Cardiology

Boston Sci’s ENERGEN and PUNCTUA Defibs Coming to EU

by Gene Ostrovsky on May 9, 2011 • 8:08 am

hl0b00ae Boston Scis ENERGEN and PUNCTUA Defibs Coming to EU
Having received the CE Mark last October, Boston Scientific is launching its ENERGEN and PUNCTUA cardiac resynchronization therapy defibrillators (CRT-Ds) and implantable cardioverter defibrillators (ICDs) in the European market. The company claims that these are the world’s smallest and thinnest high-energy AICDs.

"These devices build on the technological advancements of COGNIS® and TELIGEN® by providing options to customize therapy for individual patients," said Professor Joachim Winter, M.D., who performed one of the first implants of the ENERGEN ICD with Dong-In Shin, M.D., at the University Hospital Dusseldorf in Germany. "The small profile, coupled with the 4-SITE™ connector system, allowed for an easy implant with a less pronounced physical appearance for the patient."
"Physicians and patients will truly appreciate the longevity of these devices since it may reduce the need for additional implant surgeries," said Peter Lecher, M.D., who performed one of the first implants of the ENERGEN CRT-D with Gunther Prenner, M.D., at the Medical University in Graz, Austria. "Additionally, the new therapy options, combined with the LATITUDE® Patient Management system, increase the variety of diagnostic parameters to help treat heart failure patients."
Most of the new ENERGEN and PUNCTUA devices offer the 4-SITE™ DF4 connector system option, designed to simplify the implant procedure and comply with international connector standards. Additionally, nearly all models are compatible with Boston Scientific’s LATITUDE® Patient Management system, which enables physicians to remotely monitor implantable cardiac device patients between on-site office visits.

Press release: Boston Scientific Begins International Launch and First Implants of Next-Generation Devices to Treat Heart Failure and Sudden Cardiac Death…
Flashback: Trio of Boston Scientific Cardiac Devices CE Approved

Nanomedicine

Fractal Nanoflowers May Improve Retinal Prostheses

by Gene Ostrovsky on May 9, 2011 • 7:43 am

e8p83z8n Fractal Nanoflowers May Improve Retinal Prostheses
Researchers at the University of Oregon and the University of Canterbury, New Zealand are studying the possibility of using fractal electrodes as efficient interfaces between retinal implants and functioning retinal neurons. They’re using nanocluster deposition to create fractal electrodes, that they call nanoflowers (see side image), that should provide better coupling than traditional electronic chips.
From an article by Richard Taylor of U of Oregon in Physics World:
cqfxgq3y Fractal Nanoflowers May Improve Retinal Prostheses

During the deposition process, the nanoflowers nucleate at points of roughness on the substrate. Therefore, when nanoflowers are grown on top of the implant’s photodiodes, the surface roughness will be exploited to "automatically" grow the nanoflowers, making this a highly practical process for future implants. One challenge of the growth process lies in reducing nanocluster migration along nanoflower edges, which smears out the fine branches. This can be achieved by tuning the cluster sizes (which range from several nanometres up to hundreds of nanometres) and adjusting their deposition rate.
The nanoflowers can be grown to match the size of the photodiodes (20 µm), and will feature branch sizes down to 100 nm. Many of the gaps between the fractal branches will therefore be smaller than the wavelength of visible light, opening up the possibility of using the physics of fractal plasmonics to "super lens" the electromagnetic radiation into the photodiodes.
Significantly, the inherent advantages of the nanoflower electrodes lie in adopting the fractal geometry of the human eye rather than the Euclidean geometry of today’s cameras.

UOregon statement: Forecast calls for nanoflowers to help return eyesight…
Article in Physics World: Vision of beauty

Radiology / Vascular Surgery

Hotspur’s Three-In-One IQCath Catheter Cleared for Use in Europe

by Smit Shah on May 6, 2011 • 11:25 am

iqcath Hotspurs Three In One IQCath Catheter Cleared for Use in Europe
Hotspur Technologies (Mountain View, CA) has announced CE Mark approval of its IQCath Balloon Dilatation Catheter to treat blocked artificial vascular access vessels in dialysis patients. Normally, when patients with obstructed AV fistulas and such undergo a revascularization procedure, vascular surgeons need to use different devices to perform embolectomy, and/or angioplasty, or to deliver contrast agents. The IQCath can perform all three of these functions without requiring the use of multiple catheters, which the company claims will reduce procedure time and cost.
From the press release:

The IQCath catheter is indicated for use within synthetic dialysis access grafts to remove embolic material and to dilate obstructive blockages. Based on the use of Hotspur’s proprietary VisioValve™ technology, the IQCath catheter enables these functions to be performed with a single catheter, allowing a physician to perform balloon angioplasty, fluid injection, and thrombectomy while maintaining guidewire position. The ability to perform all three of these functions without removing the catheter can potentially enable use of a single Hotspur device to complete an entire procedure.



Press release: Approval Allows Patients Outside US to Benefit from Multi-Functional Device…
Product page: The IQCath™ Balloon Dilatation Catheter…

Cardiac Surgery / Cardiology

Sorin Group’s New PARADYM RF ICDs and CRT-Ds Get CE Marked

by Smit Shah on May 6, 2011 • 10:57 am

PARADYM Sorin Groups New PARADYM RF ICDs and CRT Ds Get CE MarkedMilan, Italy based Sorin Group has announced CE marking of its new PARADYM RF line of implantable cardiac defibrillators (ICDs) and cardiac resynchronization therapy devices (CRT-D). The new devices are compatible with Sorin’s SMARTVIEW system, which lets doctors remotely monitor patients, and also incorporate the SafeR and Parad+ algorithms to prevent the delivery of unnecessary shocks.
From the press release:

PARADYM RF™ CRT-D and ICDs are designed to provide patients with the optimal combination of thinness, high power and longevity. Utilizing state-of-the-art battery and capacitor technology and an innovative remote monitoring design featuring high speed data transfer and monitor-initiated connection, the PARADYM™ RF CRT-D and ICD devices deliver 37J of energy with longevity over 6 years and 9 years respectively in an 11mm thin device.
The PARADYM™ RF family includes Sorin’s proprietary SafeR™ and Parad™+ algorithms that automatically adjust to each individual patient to minimize right ventricular pacing and inappropriate shocks.
The PARADYM™ RF CRT-D also features a new programming option to electronically reprogram the device to avoid phrenic nerve stimulation, a common side effect of resynchronization therapy. In addition, PARADYM™ RF CRT-Ds include Sorin’s exclusive Brady-Tachy Overlap (BTO™) algorithm that provides pacing therapy during exercise while maintaining the ability to detect and treat slow ventricular arrhythmias.

Press release: Sorin Group Receives CE Mark Approval for PARADYM™ RF ICDS And CRT-D
Product pages: Parad/Parad+; SafeR

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