BBI Contributing Writer

BURLINGAME, California Some of the world's leading researchers and entrepreneurs in neurodiagnostics, neuromodulation and neural prostheses participated in the third annual "Neurotech Leaders Forum" last month. The day-long event at the Hyatt Regency San Francisco Airport offered an opportunity for researchers and executives in the neurotechnology field to interact with venture capital firms and other funding organizations.

According to James Cavuoto, editor and publisher of Neurotech Business Report, the worldwide market for neurotechnology products and services is expected to be approximately $2.4 billion in 2004, increasing to approximately $7.2 billion in 2008. This includes applications in neurostimulation and neurodiagnostic devices.

Neurotech Business Report divides the healthcare market for neurotechnology into four segments: neurodiagnostics, neural prostheses, therapeutic electrical stimulation, and neuromodulation. The neuromodulation market expected to be approximately $1.1 billion in 2004, rising to approximately $3.6 billion in 2008 is currently the largest segment of the overall neurotechnology market, "and is likely to remain so for several years," said Cavuoto. "Implanted stimulators for pain treatment represent the largest subcategory in this category," he added.

The neural prostheses segment expected to be approximately a $617 million market in 2004, growing to approximately $2.2 billion in 2008 "is dominated presently by cochlear prostheses, which are expected to generate sales of approximately $552 million in 2004, and grow to an expected market of $1.7 billion in 2008," Cavuoto said.

The market for therapeutic electrical stimulation products, though it is the smallest of the four healthcare segments at approximately $212 million in 2004, is expected to grow to $446 million in sales by 2008. According to Cavuoto, growth and regulatory approval of therapeutic electrical stimulation products for treating stroke will be the largest factor driving sales in this category.

Neurodiagnostics "refers to the use of electronic sensing and testing systems that measure human neural activity in order to diagnose neuropsychiatric or neurological disorders and injuries," said Chris Berka, chief executive officer of Advanced Brain Monitoring (Carlsbad, California). This segment is expected to be about $479 million in 2004, growing to an expected $995 million by 2008. Neurotech Business Report divides this segment into three categories: 1) systems based on electrophysiological recording, 2) systems based on magnetic field sensing and stimulation and 3) systems that analyze brain state, such as drowsiness, depth of consciousness and presence of specific neurological or psychiatric diseases and disorders.

In the electrophysiological product category, the largest segment uses electroencephalographic (EEG) recording systems to monitor brain activity. These systems normally include sophisticated software algorithms that process the analog data coming from multiple electrode locations on the scalp; they also include related applications for visualizing the results of testing, and often incorporate a means of detecting evoked potentials, significant electrophysiological patterns that result from applied stimulation or motor output. Cavuoto said that the leading manufacturers of this type of equipment include Viasys Healthcare's (Conshohocken, Pennsylvania) Nicolet Biomedical unit (Madison, Wisconsin), Bio-Logic Systems (Mundelein, Illinois) and Oxford Instruments (Witney, UK).

One of the major applications of electrophysiological neurodiagnostic equipment is polysomnography. These diagnostic devices monitor several physiological parameters including EEG and EMG, but also including non-neurotechnology measurements of electrocardiograms, blood gases, body temperature, and other indices. Compumedics (Abbotsford, Australia) manufactures a range of polysomnography systems.

Another application of neurodiagnostics is in diagnosis and testing of peripheral nerve disorders such as neuropathy and repetitive strain injury. NeuroMetrix (Waltham, Massachusetts) makes a noninvasive nerve-conduction monitoring system that evaluates neuropathies in the peripheral nerves. The product works by stimulating the median, or ulnar, nerve with short electrical bursts and then evaluating the muscular response.

Another segment of neurodiagnostics is magnetoencephalographic (MEG) recording systems that monitor the extremely small magnetic signals emanating from the brain. Compared to EEG-based equipment, MEG systems can produce a more meaningful map of brain activity "in large part because magnetic fields are able to penetrate the human skull and other biological elements that seriously degrade electrical signals," said Cavuoto. He added that MEG systems are capable of distinguishing brain activity from areas of the cerebral cortex within two to three millimeters.

The largest manufacturers of MEG neurodiagnostic equipment are 4-D Neuroimaging (San Diego, California) and VSM MedTech (Vancouver, British Columbia), which manufacture MEG systems used in clinical labs for epilepsy evaluation and presurgical functional mapping. Neurotech Business Report estimates that the worldwide market for neurodiagnostics systems based on magnetic technologies will be approximately $84 million in 2004, growing to approximately $193 million in 2008. Factors contributing to this growth include increasing demand for more precise neurophysiological maps of the human brain, in both research and clinical settings. MEG systems also stand to benefit from an increased amount of government and private funding for neuroscience research. "The category will also grow with the entry of new magnetic recording and stimulation products making use of more compact design and reduced power requirements," Cavuoto said.

Several new technological developments that may impact the neurotechnology industry toward 2010 were discussed. Electrode design represents one of the most significant areas of technological improvement for the neurotechnology industry. As microelectrodes become smaller and their electrical and material properties become more rich, they will offer new capabilities to neural engineers building stimulation and sensing products.

One of the most significant advances to date in electrode design is the nerve cuff electrode, developed at Case Western Reserve University's (Cleveland, Ohio) department of biomedical engineering. The nerve cuff electrode forms an electrical "collar" around a nerve trunk, and "thereby offers several independent locations around the circumference of the cuff where stimulation can be delivered," said Warren Grill, PhD, associate professor of biomedical engineering at Case Western. "These independent locations deliver a much higher degree of specificity than do traditional electrodes with just one stimulation location, enabling engineers in many cases to select the specific nerve fibers to be activated."

Another area of improvement in electrode design incorporates stimulation and sensing functions into the same electrode, an important consideration for neural prostheses that make use of feedback from the nerve or muscle being stimulated to control stimulation patterns.

In addition, researchers talked about advances in signal processing hardware and software that will lead to new developments in future neurotechnology products. In particular, sensors that analyze electroencephalographic or magnetoencephalographic data in order to diagnose neurological, psychiatric, or behavioral abnormalities will benefit from new software algorithms and signal-processing electronics. "The mechanisms of central nervous system control over human cognitive and motor functions are so poorly understood that efforts to replicate or restore are severely hindered," said Jennifer French, executive director of the Society To Increase Mobility (Tampa, Florida). "Software and hardware signal processors that analyze data from multiple channels simultaneously will help researchers identify patterns that correspond reliably to mental states or conditions."