Combination Therapies: Is this the next generation of rehabilitation?

Posted by Jennifer French  innovative technology, restoring neural functions  No Responses »
May 132012
 

Combining several therapies to build a rehabilitation treatment plan for neurological conditions is nothing new.  However, combining a variety of technologies into a treatment plan to produce functional outcomes is an emerging theme among innovative rehabilitation professionals. The roots of combining the rehabilitation with electrical stimulation to improve motor re-learning come from the pioneering work by Dr. Randolph Nudo and Dr. Alvaro Pascual-Leone in 1990es.

Recently, this approach was applied by combining the robotic therapy with electrical or magnetic stimulation by a team of researchers lead by Dr. Lumy Sawaki at the University of Kentucky in Lexington. This new neural rehabilitation technique capitalizes on “neuroplasticity,” which refers to the brain’s ability to reorganize itself by forming new neural connections to compensate for injury and disease.  Dr. Lumy Sawaki, MD, PhD, an Associate Professor in the Department of Physical Medicine and Rehabilitation at the University of Kentucky, has been exploring how combining technologies in the rehabilitation setting may help her patients regain functional movements. This new therapy is based on previous work she had done involving CIMT, constraint-induced movement therapy.  Dr. Sawaki was the lead author on a CIMT study published in the journal Neurorehabilitation and Neural Repair.   In this study, each of the 30 participants was evaluated using transcranial magnetic stimulation (TMS), a non-invasive method to excite neurons in the primary motor cortex. In the CIMT therapy study, Dr. Sawaki and collaborators used TMS to map the area of the brain that controls a particular muscle and compared this map to previous patterns of activity. As the patient’s ability to perform a certain movement improves, these brain maps confirm the reorganization of the associated area of the brain. Focusing on hand motor function of sub-acute stroke survivors, they observed changes within the functional activity of the brain for those who used CIMT.

Building on this previous work, Dr. Sawaki and her research team are evaluating the combined approach to stimulate the brain with two painless and non-invasive methods: the magnetic stimulation with TMS and the electrical stimulation with transcranial direct current stimulation (tDCS), to develop a new neural rehabilitation therapy for chronic survivors of neurological trauma from stroke, brain and spinal cord injuries. In this new therapy, the TMS and tDCS is applied along with robotic movement therapy, such as body weight supported treadmill training. Dr. Sawaki is using TMS and tDCS to stimulate the area inside the motor cortex that controls movement of a targeted muscle. By applying multiple stimuli and monitoring the muscle response combined with robotic therapy, the investigators are attempting to determine if this combination will result in higher functional benefit.

Conclusive evidence is still lacking but it brings the promise of combined neural rehabilitation therapies paving a new path for how we approach complex neurological conditions in the rehabilitation setting.  Click here to read more about Dr. Lumy Sawaki’s research and new neurorehabilitation therapy.

Build your own amplifier for electrophysiological recording @ US$10 per channel!

Posted by Monzurul Alam  innovative technology  3 Responses »
Mar 292012
 

It is well known that building a setup for recording neural spikes is not trivial. Many older electrophysiological systems are bulky, expensive and difficult to use. Their system components require elaborate shielding and grounding  to reduce the electromagnetic interference. Recently, the technology advances have been quite rapid. It has become possible to build the millimeter-scale electrophysiology amplifiers from commercial off-the-shelf components. Here, I would like to share an amplifier design that is capable of intracellular and extracellular recording, as well as LFP, EMG, and EEG. It is small, easy to build and extremely cheap. The system uses differential mode of recording, thus eliminating the need of extensive shielding from environmental noise. The circuit had been tested on freely-moving animal exposed to their regular environment and was able to record neural spikes with a good signal-to-noise ratio (SNR).

The amplifier is divided into two stages. The first stage is an Instrumentation Amplifier (IA) with the differential input. The input signals have DC removed (with a high-pass filter) with highly tuned RC components. It is important to have very closely matched components to have high Common Mode Rejection Ratio (CMRR). The capacitors Cpf and Cnf are for power supply regulation with typical value of 0.1µF. The gain of the instrumentation amplifier is typically set in the range from 100 to 1000. The second stage is a second order low-pass filter (sellen-key). The gain of this filter should be maintained about 10; resulting in a total gain of the amplifier of ~10,000.

Following are the example values for the filter amplifier:

Chp1 = CHR = 100nF, RH1 = RHR = 4.68MΩ; Low Cut-off frequency = 0.34Hz;

R1= 10kΩ, R2= 150kΩ, C1= 1nF, C2= 1nF, R3= 10kΩ, R4= 100kΩ; High Cut-off frequency = 4,109Hz;

NOTE: For multiple channels build the same circuit and use them in parallel. For single reference electrode just short all the inverting terminals (-) of all instrumentation amplifiers and use only one reference high-pass filter (CHR, RHR) instead.

Cortical and spinal neuromotor prosthetics: who would be an ideal candidate?

Posted by Monzurul Alam  restoring neural functions  1 Response »
Mar 282012
 

Central-nervous-system based neuromotor prosthesis (NMP) holds a great deal of promise for complete spinal cord injury (SCI) yet is still far from the clinical use.  Cortical-level NMP uses direct cortical recording and requires craniotomy for implanting a microelectrode array in the motor cortical area of an injured person. First successful human trial of the cortical NMP in a quadriplegic person, the BrainGate, was done by Dr. Donoghue and colleagues back in 2006. Last year, Dr. Edgerton and colleagues have applied a spinal NMP to train a paraplegic person to stand and walk on a treadmill.  As these cortical and spinal NMPs are reaching maturity, the question emerges, whether all people with SCI can benefit from this technology. In this post, I will try provide my perspective about the potential technology users.

SCI has different severity, motor complete or incomplete, and occurs at different spinal levels, from cervical to thoracic and lumbosacral, resulting in quadriplegia or paraplegia. NMP is potentially most viable for motor-complete SCI since people with incomplete SCI can benefit from extensive rehabilitation training. Quadriplegics with motor-complete SCI would likely benefit the most from this technology. One of major challenges for implementation of cortical NMP for quadriplegics is the availability of real-time adaptive decoding algorithms for controlling the body balance, needed to enable standing and locomotion. As a quadriplegic person completely loses his/her posture control, it is unlikely that they could use existing decoding algorithms for cortical NMP for standing and stepping. Still, such a person can use the cortical NMP for controlling an external device or an upper limb (through stimulation of peripheral nerves or muscles). Volitional control of an individual hand muscle by this kind of cortical CNMP has already been demonstrated in non-human primates by Dr. Fetz and colleagues.

It is not clear whether paraplegics can benefit from the NMP technology to the same degree as quadriplegics. As paraplegics have useful hand and arm functions, cortical NMP might be too risky and invasive of a procedure to justify the potential benefits. Perhaps, a spinal NMP controlled by a hand or a processor that interprets the person’s movement intent can be more beneficial for standing and walking. In a spinally-intact person, the leg movements and locomotion require no visual feedback and are adjusted in time and space through a local feedback circuitry in lumbo-sacral region of spinal cord. Provided that this feedback loop is intact in the paraplegic person, would be extremely beneficial to use this loop along with the spinal Central Pattern Generator (CPG) for enabling the locomotion. Recent human studies by Edgerton and others indicate simply turning these spinal neural circuits ON and OFF might not be enough for standing and/or stepping. Hopefully, with more robust decoding and encoding algorithms, the spinal NMP might become a viable clinical solution for paraplegics.

Considering these arguments, I would like to suggest that an ideal candidate for cortical NMP would be a quadriplegic, while an ideal candidate for spinal NMP would be a paraplegic.

 

 

First flexible organic transistor to withstand considerable heating

Posted by Victor Pikov  innovative technology  No Responses »
Mar 252012
 

An international research team from Japan, Germany, and United States reported creating a flexible organic transistor that features good thermal stability at temperatures up to 150°C. The new transistor has been fabricated with a biocompatible polymeric substrate (Parylene), making it potentially useful for ECoG and other types of implants. Fabrication of many implantable devices involves some steps that have to be performed at elevated temperatures (e.g. parylene annealing). In addition, device sterilization is also commonly done at elevated temperatures of 130-170°C and (optionally) an elevated chamber pressure, in a process called autoclaving. The autoclaving, done at 150°C and atmospheric pressure, takes less than 3 hours, faster than room-temperature sterilization using ethylene oxide (24 hours).

The key technological achievement in the reported study is the use of an ultrathin (2 nm) heat-resistant monolayer film for insulation between the organic semiconductor and its gate. The monolayer is synthesized by a self-assembly of long-tailed phosphonic acids and has a densely packed crystalline (rather than amorphous) structure. Such ordered chemical structure prevents a formation of pinholes during heating. The use of ultrathin monolayer between the semiconductor and its gate instead of thicker dielectric films allowed the researchers to reduce the transistor driving voltage from 20V to 2V, making it more suitable for neuroprosthetic applications. Main limitation of the reported study is the short duration of the applied heat stress (20 sec), which does not evaluate a possibility of a slow heat-induced degradation of the self-assembled monolayer.

Direct-to-consumer transcranial direct-current stimulation device

Posted by Victor Pikov  enhancing neural functions, neurotech business  3 Responses »
Mar 182012
 

A few months ago, our blog post discussed a possibility of direct-to-consumer neurotech devices reaching the market in a near future. Among available brain stimulation techniques, transcranial direct-current stimulation (tDCS) is a fairly simple non-invasive method for cortical stimulation. A recent study, conducted by researchers at the University of New Mexico, seems to support the cognitive-enhancing effect of the technique. Learning and performance in a shooting video game was increased two-fold following 30-min tDCS as compared to control, even after one-hour delay. Other studies found beneficial tDCS effects on working and visual memory. Capitalizing on the enthusiasm generated by these studies, the website GoFlow is planning to offer a DIY kit for tDCS with a price tag of $99! Understandably, the kit is very bare-bone, and includes only a battery, a few scalp electrodes, resistor, and a potentiometer.  I would venture to guess that the kit would attract avid brain-hacking enthusiasts and perhaps some students desperately trying to memorize the material before the exam. For the rest of us, let’s wait for a more mature product to hit the shelves.

PMA approval process is now required by FDA for Cranial Electrotherapy Stimulator devices

Posted by Victor Pikov  neurotech business, neurotech market  No Responses »
Mar 092012
 

In order to use a medical device in the US, a device manufacturer has to get an approval from FDA. Invasive devices, such as neural implants, are classified as Class III and can be approved in one of two ways: 1) a comprehensive “de novo” Premarket Approval (PMA) or 2) a streamlined 510(k) clearance, also called a Premarket Notification (PMN), when the device is “substantially equivalent” to an existing approved device. The complete device development and approval process takes 4-10 years and costs $5-300 million depending on the complexity of the device and FDA approval process. Approximately 40 PMAs and 3,000 510(k) clearances are approved each year by the FDA.

Cortical and spinal neural implants are among the most invasive and, therefore, always require a PMA approval. In comparison, the “Cranial Electrotherapy Stimulator” (CES) devices, are implanted under the scalp and pose fewer surgical risks. Until recently, they required only a 510(k) clearance, and such relaxed approval process resulted in their multiple applications for neurological and psychiatric disorders, such as anxiety, depression, insomnia, chronic pain, and migraine.

In August 2011, FDA proposed a new rule to require PMAs for CES devices, and the device makers responded by proposing instead that the devices be given less stringent Class II status, which often does not require PMA approval. In February 2012, the Neurological Devices Panel of the Medical Devices Advisory Committee at the FDA advised against such downgrade, so the CES devices would still require a lengthy and expensive PMA process. According to recent estimates, an average PMA approval process would take ~27 weeks and would cost the CES device makers an additional $1 million, as compared to 510(k).

Deep brain stimulation for respiratory airway relaxation in asthma

Posted by Victor Pikov  restoring neural functions  No Responses »
Feb 242012
 

Upper (e.g. bronchial) airways become constricted in people with asthma or chronic obstructive pulmonary disease. The bronchial smooth muscle contraction is mediated by the parasympathetic nervous system, while the relaxation is mediated by the sympathetic nervous system. The periaqueductal gray matter of the midbrain (PAG) and subthalamic nucleus (STN) are involved in maintaining the bronchial relaxation. The electrical stimulation of the PAG is approved for chronic pain and electrical stimulation of the STN – for movement disorders (Parkinson disease and dystonia). A new study by a group of neurosurgeons from Oxford, United Kingdom evaluated the effects of the PAG and STN stimulation with DBS electrodes on the bronchial airway function. They found that activation of both brain structures in awake human subjects produced similar increases in the airway flow of 10-12%, with some patients exhibiting even larger increases (up to 30%). While similar effects were seen in both PAG and STN, the used stimulation frequencies were quite different: 7-40 Hz in PAG and 130-180 Hz in STN. It is important to mention that PAG is considered to be a major integration center for multiple autonomic functions, such as cardiovascular responses, thermoregulation, respiration, bladder and bowel voiding, arousal, and rapid-eye-movement (REM) sleep. This study raises an important question whether asthma is a neurological disorder that can be treated by neuromodulation?

NeuroNexus acquisition by Greatbatch: silicon-based probes are getting closer to clinical market

Posted by Victor Pikov  neurotech business, neurotech market  2 Responses »
Feb 172012
 

In recent years, the medical manufacturing company Greatbatch Inc. has made several steps indicating its ambition to become a major player in the neuroprosthetic device arena, currently dominated by Medtronic, St. Jude, and Boston Scientific. Until recently, Greatbatch’s two subsidiaries, Greatbatch Medical and Electrochem Solutions, were mostly known for producing the pacemakers, vascular catheters, orthopedic implants, leads, and batteries. The company does not market any neurostimulation devices, although several other manufacturers use Greatbatch’s batteries and leads in their neuromodulation implants (e.g. obstructive sleep apnea device by Inspire Medical). In fact, 95% of all pulse generators worldwide contain at least one Greatbatch’s component. In 2008, Greatbatch created the QiG Group, its third subsidiary, with a goal of making targeted investments in innovative cardiovascular catheters and neuromodulation devices. Last year, QiG has started the Algostim brand of spinal cord stimulation devices to treat chronic pain, The QiG has also invested, along with Boston Scientific, into Intelect Medical, an early-stage company developing deep brain stimulation devices for traumatic brain injury, and stroke. And most recently, on February 17, 2012, Greatbatch’s QiG Group announced its acquisition of NeuroNexus for $12 million. Dr. Daryl Kipke, NeuroNexus President and CEO, indicated that its technologies would be used to develop novel “neuromodulation clinical therapies”. It remains to be seen whether the Greatbatch’s definition of “neuromodulation” will be modified, as the key NeuroNexus technologies, the high-density silicon-based electrodes and their interconnects, are more suited toward neuroprosthetic rather than neuromodulation therapies. But, in any case, this news brings us one step closer to a long-awaited clinical trial of probes developed using the semiconductor microfabrication technologies.

ICNPD-2011 conference in Sydney tackles unresolved issues in neuroprosthetics

Posted by Victor Pikov  neurotech conferences  No Responses »
Feb 162012
 

The ICNPD-2011 conference took place on November 25-26 2011 on the campus of University of New South Wales in Sydney, Australia. As a co-chair of the conference, it is my great pleasure to report on its results.  The conference drew 70 participants, and included 25 speakers from 9 countries (Australia, China, Denmark, Germany, Korea, Singapore, Taiwan, UK, and USA). Owing to a multi-disciplinary nature of the neuroprosthetic research, the talks were given by scientists, engineers, neurosurgeons, and rehabilitation physicians and covered a wide range of topics, such as new materials, surgical approaches, uses of electrochemical and neurophysiological recordings, circuit design, and signal processing algorithms. During the poster session, 16 posters were presented, including 8 student posters evaluated by the members of Scientific Committee. The Best Student Poster award, the iPad2, was given to Dr. Spencer Chen, a post-doctoral fellow at the University of New South Wales; and the runner-up award was given to Dr. Chandan Reddy, a post-doctoral fellow at the University of Iowa. Following the conference, a series of online discussions were held with the speakers to come up with a list of Grand Innovation Challenges in Neural Prosthetics:  http://neurotechzone.com/icnpd-2012/grand-challenges. These challenges are subdivided by the following clusters: Visual prosthetics, Auditory and vestibular prosthetics, Motor/BMI prosthetics, neuromodulation for pain control, Electrode-tissue interface, Insulation and encapsulation, and Packaging. This list will continue to be updated based on your feedback, so please read it thoroughly and don’t forget to leave your comments.

A subset of these challenges will be selected, based on your input, for discussion at the ICNPD-2012 that will take place later this year in Freiburg, Germany: http://neurotechzone.com/icnpd-2012

Decoding individual words from human superior temporal gyrus

Posted by Victor Pikov  enhancing neural functions, restoring neural functions  No Responses »
Feb 032012
 

The neuroscientists at UC Berkeley conducted the study in 15 patients with epilepsy or brain tumor, in which the subdural electrocorticographic (ECoG) recordings were used for deciphering the speech processing in the cortex. Brain activity was induced in the superior and middle temporal gyri, the cortical regions involved in speech comprehension, by listening to words. Each word was played to a patient for 5-10 minutes to collect enough data for analysis. The spectral features of the sounds were used for linear and non-linear regression algorithms in order to reconstruct the words from the pattern of brain activity. The reconstructed words were intelligible enough to recognize them, although they sounded as if spoken under water. The proposed technology is still rather immature but one day it hopefully would be able to convert the ECoG activity in the auditory cortex into spoken language for patients with a stroke, locked-in syndrome, and other disorders resulting in a paralysis of their vocal cord and arms (think of Stephen Hawking).

Ion-selective electrodes for manipulating cation availability in nerve stimulation and for neural conduction block

Posted by Victor Pikov  innovative technology, restoring neural functions  No Responses »
Jan 152012
 

During stimulation, the applied electrical charge induces similar flows of multiple extracellular cations (K+,Na+ and Ca2+) in the electrode vicinity. This is rather counter-productive as these cations play varying roles in the initiation and propagation of action potentials. As a result, a significant percentage of applied electric charge is being wasted. Now, scientists at MIT and Harvard Medical School have reported a way to alter the cation concentrations using commercially available cation-selective resin solutions deposited on planar electrodes. In one experiment, they applied small positive DC current (≤1µA, 10 to 100 times below the nerve activation threshold)  to a centrally-located calcium-selective electrode for 1 min to deplete Ca2+ concentration from the fluid surrounding the nerve. Immediately thereafter, they applied the supra-threshold electrical pulses between two lateral uncoated electrodes, while the central electrode was off. The researchers achieved a 70% decrease in the amount of current required for reaching the nerve activation threshold. In another experiment, the K+- and Na+-selective electrodes were used to deplete the concentrations of these ions at some distance from the stimulating electrode. Such cation depletion caused a complete conduction block for 10 min after applying a cation-depleting DC current of 1µA for 5 min. Both K+- and Na+-selective electrodes were equally effective in blocking the action potential propagation. This finding could have important applications in shutting off the nociceptive neural activity in relieving chronic pain. Finally, the developed cation-selective electrodes have two important features making them attractive for neuroprosthetic applications: 1) they can be microfabricated and 2) they do not require a chemical reservoir for their operation.

Blood entry sensor for cerebral embolization using RF resonance of micro-coils

Posted by Victor Pikov  innovative technology, restoring neural functions  No Responses »
Nov 122011
 

About 3 -4% of the general population has or will develop a cerebral aneurysm, with most are without any symptoms. Aneurysm is an enlarged area of a blood vessel that usually develops at a branching point of artery and is caused by constant pressure from blood flow. It often grows gradually and becomes weaker as it stretches. Rupture of a cerebral aneurysm causes bleeding into the brain, often leading to a stroke. Endovascular embolization using micro-coils has emerged as a successful preventive treatment for aneurysms. The micro-coils are made from platinum wire (thickness 20–120 μm) wound at diameters of 200–500 μm for length up to 50 cm. Once the coil is inserted through the artery into the aneurysm, it forms a randomly tangled globe that promotes clotting of blood, thus preventing further inflow of blood and pressure rise. In about half of implanted patients,
the embolization process fails within 18 months, requiring frequent checks for the blood entry into the aneurysm using expensive, invasive, and potentially toxic methods, such as X-ray angiography and computer tomography. The group of Dr. Takahata at the University of British Columbia has reported a new method for monitoring blood entry into aneurysms, which is simple and inexpensive enough for frequent monitoring at home. In their method, the RF resonance of the micro-coils is used as a moisture sensor.  The RF resonant circuit is formed by self-inductance combined with parasitic capacitance, which is affected by tissue permittivity around the coil. At 100 MHz, for example, the dielectric constant of blood is 25 times higher than that of fibrous tissue. The RF coupling of the micro-coils would be done with an external antenna attached to the head of a patient. The present study was conducted using animal muscle tissues, with a clinical device
anticipated in 2-3 years.

Consumer-oriented neural interfaces for non-medical applications

Posted by Victor Pikov  enhancing neural functions, neurotech business, neurotech market  1 Response »
Oct 232011
 

As documented in other posts on this blog, mutliple neural prosthetic devices are currently being developed by startup companies throughout the US, Europe, and Asia. Practically all of these startups are pursuing the well-established R&D strategy of building a device to treat a specific neurological disorder and going through a lengthy process toward eventual FDA approval and reimbursement by private and government-run health insurance companies. In following with this R&D strategy, the resulting device is usually fully implanted and contains only the circuitry needed for its primary function to treat a specific disorder. The device is designed for autonomous operation without user accessibility, and any device’s software tuning/upgrade requires a physician and specialized clinical equipment. These features are aimed at limiting the manufacturer’s and surgeon’s liabilities.
Here, I would like to propose a possibility of developing the consumer-oriented neural interfaces. Such a strategy is inspired by recent developments in the consumer electronics industry and, particularly, by a wide adoption of body-worn health monitoring gadgets (such as a sleep sensor Lark, EEG monitoring device Mynd, and muscle stimulator Compex). The proposed new strategy requires a fundamental shift in the user attitudes toward body-worn neural interfaces. Instead of treating the neural interface as a “band-aid” for restoring the lost or damaged neurological function, the users would treat the neural interface as a sensory or motor extension of their existing own nervous system. The following table illustrates the key attributes that differentiate a conventional neurological treatment device from a consumer-oriented device:

Attribute Conventional device Consumer-oriented device
Usage Repair of lost/damaged neural functions Enhanced use and preventing the decay of existing neural functions due to Alzheimer’s
Customer Hospital, doctor End user
Reimbursement Health insurance company End user
Implanted components Electrodes, active electronics Electrodes only (minimally-invasive placement)
Body-worn interface (BWI) Telemetry for battery re-charging and data input/output User-controlled multi-purpose graphical computer interface
Placement of BWI Inconspicuous or hidden from view Prominent
Operation of BWI Primarily by a physician By the end user
Communication with other devices None (standalone use) Standard wireless protocols (Bluetooth, WiFi, 3G)

 

As can be seen in the table above, the fundamental changes in the R&D strategy relate to every aspect from the device marketing to its configuration, operation, and user control. The reduced complexity and size of the implanted device are crucial for allowing a minimally invasive implantation that can be performed by a neurologist (rather than a neurosurgeon) in an outpatient clinic. Fabrication of a simple implantable device combined with a simple surgery can dramatically reduce the overall user cost (perhaps to a sub-$10,000 level) and therefore make the devices applicable for non-medical applications, such as memory improvement, cognitive training, and around-the-clock personal assistance.

Continuing the parallel with the consumer electronics, let’s think for a moment about our computer use just 10 years ago. The computers back then could serve specific functions, such as data entry, word processing, accounting, etc. Our everyday lives, however, have been rather “un-tethered”, as we lived our lives oblivious to a possibility of having constant access to our email inbox or a Facebook status. There is no denying, that we are evolving into a new social species, the “homo twitterus”, with the reported ~60% of smartphone users waking up voluntarily during the night to check their messages. Let’s compare that with our evolving attitude toward the neural interfaces.  In the classic SciFi movies Star Trek: First Contact (1996) and The Matrix (1999), a images of the brain and spinal interfaces were positively repulsive. A decade later, in the movie Tron: Legacy (2010), the Identity Discs worn by the Grid inhabitants, prominently featured on their back, appear rather attractive and stylish. The public interest in the consumer-oriented neural interfaces may start initially among the techno-gadget aficionados and gradually spread to general population. Similar evolution has occured with the computer use and has now reached the stage where pure functionality and low cost of the device are no longer as important as its esthetic, social-status, and “coolness” appeal (think of Apple’s Macbook Air, iPad, and iPhone). While many Android phones are arguably more feature-rich and less expensive than iPhone 4S, Apple Inc. is enjoying robust growth by strengthening its deep personal relationship with customers and by changing their lifestyle in a profound way. The proposed consumer uses of neural interfaces can bring such device-user relationship to a whole new level, with the person’s everyday life being dependent on bidirectional exchange with their body-worn personal assistant. A rich virtual environment provided by the neural interface can be used, for example, by retired baby-boomers for muscle exercise and rehabilitation; memory improvement and cognitive fitness; and learning of visual and motor skills (e.g. golf, tennis, driving). Many other applications, perhaps even more pervasive and lifestyle-changing (such as novel sensory/motor modalities), could emerge as the neural interface technology takes hold in the society.

DBS for Alzheimer’s disease

Posted by Victor Pikov  enhancing neural functions, neurotech business, restoring neural functions  No Responses »
Oct 202011
 

As the number of people with Alzheimer’s disease (AD) is rising with aging population, there is an increasing urgency in developing an effective approach to slow its progression. Despite the efforts by pharmaceutical companies, currently approved drugs provide only modest effects and are often difficult to target to the brain without avoiding the systemic side effects. A possibility of using electrical stimulation for combating the disease has not been considered until a serendipitous discovery reported in 2008 by Dr. Andres Lozano, a neurosurgeon at the University of Toronto. He applied the DBS stimulation at the satiety-controlling region of the brain, the fornix, in a patient with morbid obesity with a hope of reducing the sensation of hunger. Surprisingly, the psychological tests have shown a significant improvement in patient’s memory. The follow-up study in AD patients, published in 2010, showed that the fornix stimulation can slow the memory decay. The authors of the study speculate that possible mechanism of action involves plasticity in the limbic circuitry counteracting the AD-related neurodegeneration. As a result of these findings, a startup company called Functional Neuromodulation Inc. was formed in 2010 to commercialize the DBS use in the fornix for AD patients. It recently obtained funding from Genesys Capital and Medtronic to conduct the second clinical trial in the AD patients. It is worth mentioning that other companies, such as Medtronic and St. Jude Medical, have considerable intellectual property on electrical stimulation of other limbic areas, such as the anterior thalamic nucleus, internal capsule, and subgenual cingulate cortex, which may also play an important role the memory formation process. We will anxiously await further developments in the use of DBS to counteract the progression of AD.

Active tactile exploration using a brain-machine-brain interface

Posted by Justin Sanchez  enhancing neural functions, restoring neural functions  No Responses »
Oct 072011
 

The quest for highly functional neuroprosthetics in activities of daily living has implicitly assumed that the neural interface would include both motor and sensory (i.e. tactile and proprioceptive) functionalities. It is likely that for reaching and grasping tasks, the dynamic sensorimotor programs will need to be developed to enable dexterous control. Interestingly,  the neural decoding, stimulation, and hardware principles for sensorimotor interfaces are often developed in isolation in motor-only or sensory-only studies. In this week’s issue of the journal Nature, a new study was published by Prof. Nicolelis group from Duke University attempting to create a bi-directional sensorimotor neural interface for reaching tasks. Primates used both direct brain motor control and artificial tactile sensory feedback delivered back to the brain to complete the task. Both the motor and sensory channels bypassed the subject’s body, effectively liberating a brain from the physical constraints of slow nerve implse propagation  through the nervous system. Potential use of such bidirectional control is not limited to artificial limbs and can include fast communication with a variety of external sensors and actuators.

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