Reliable chronic recordings from implanted neural probes remain a significant challenge; current silicon-based and microwire technologies experience wide range of biotic abiotic failure modes contributing to loss signal quality.A multi-prong alternative strategy with potential overcome these hurdles is introduced that combines novel three dimensional (3D), polymer-based probe structure coatings. Specifically, the Parylene C sheath-based coated neurotrophic anti-inflammatory factors loaded...

Activated iridium microelectrodes were implanted for 450–1282 days in the sensorimotor cortex of seven adult domestic cats and then pulsed 240 h (8 per day 30 days) at 50 Hz. Continuous stimulation 2 nC/phase with a geometric charge density 100 µC cm−2 produced no detectable change neuronal tissue surrounding microelectrode tips. However, pulsing continuous 100% duty cycle 4 200 induced loss cortical neurons over radius least 150 µm from electrode The same stimulus regimen but 50% (1 s...

To quantify relations between the neuronal activity recorded with chronically-implanted intracortical microelectrodes and histology of surrounding tissue, using radial distance from tip sites time after array implantation as parameters.'Utah'-type microelectrode arrays were implanted into cats' sensorimotor cortex for 275-364 days. The brain tissue around implants was immuno-stained marker NeuN astrocyte GFAP. Pearson's product-moment correlations used to these markers amplitudes action...

A new class of treatments termed bioelectronic medicines are now emerging that aim to target individual nerve fibres or specific brain circuits in pathological conditions repair lost function and reinstate a healthy balance. Carotid sinus (CSN) denervation has been shown improve glucose homeostasis insulin-resistant glucose-intolerant rats; however, these positive effects from surgery appear diminish over time heavily caveated by the severe adverse associated with permanent loss chemosensory...

Recovery of urinary tract function after spinal cord injury (SCI) is important in its own right and may also serve as a model for studying mechanisms functional recovery the CNS. Normal micturition requires coordinated activation smooth muscle bladder (detrusor) striated external urethral sphincter (EUS) that controlled by supraspinal circuitry. We used clinically relevant rat thoracic contusion to examine effect varying degree residual connections on chronic detrusor-EUS coordination....

As millimeter waves (MMWs) are being increasingly used in communications and military applications, their potential effects on biological tissue has become an important issue for scientific inquiry. Specifically, several MMW the whole-nerve activity were reported, but underlying neuronal changes remain unexplored. This study slices of cortical to evaluate individual pyramidal neurons under conditions mimicking vivo environment. The applied levels power three orders magnitude below existing...

The realization of a non-invasive monitor for determining blood glucose concentrations in human subjects is prescient driver many new techniques spanning optical, chemical, electronic and radio sensors. Microwaves offer the possibility simple, compact, non-invasive, continuous measurement level superficial tissue layers without significant heating, enzymatic reactions, or any short long term deleterious effects on tissue. This paper demonstrates first real-time direct correlative...

Many of today's radiofrequency-emitting devices in telecommunication, telemedicine, transportation safety, and security/military applications use the millimeter wave (MMW) band (30-300 GHz). To evaluate biological safety possible this radiofrequency for neuroscience neurology, we have investigated physiological effects low-intensity 60-GHz electromagnetic irradiation on individual neurons leech midbody ganglia. We applied incident power densities 1, 2, 4 mW/cm(2) to whole ganglion a period 1...

Acquisition of reliable and robust neural recordings with intracortical probes is a persistent challenge in the field neuroprosthetics. We developed multielectrode array technology to address chronic recording reliability present vivo results.The 2 × Parylene sheath electrode (PSEA) was microfabricated constructed from only C platinum. The probe includes novel three-dimensional structure, perforations, bioactive coatings that improve tissue integration manage immune response. Coatings were...

We have developed an array of microelectrodes that is suitable for long-term implantation into the subthalamic nucleus (STN) or globus pallidus and able to record from single neurons, as well deliver localized microstimulation. This device can be used investigate mechanisms by which deep brain stimulation ameliorate symptoms Parkinson's disease other movement disorders, also may basis a new clinical tool treatment disease, capitalizing on high spatial specificity intranuclear The includes 16...

A novel Parylene C-based peripheral nerve interface that combines both electrodes and microfluidic channels in an adjustable cuff was designed, fabricated, characterized. This minimally invasive incorporates a drug delivery system for targeted of lysing agents neurotrophic factors to the surface locally disrupt epineurium allow fascicular selectivity. Multiple platinum (Pt) were embedded neural stimulation recording. The lyse-and-attract electrode (LACE) uses simple locking mechanism is...

The open-source development model has been successfully applied to consumer and enterprise software, recently hardware. Medical devices may become a beneficiary of this trend, as medical device the potential reduce costs, democratize patient access, provide continued support abandoned from failed companies. Unlike market, market is highly regulated involves considerable manufacturer liability that limit use technology. This review explores current state in research clinical products suggests...

The long-term objective of this study is to develop neural prostheses for people with spinal cord injuries who are unable voluntarily control their bladder. This feasibility was performed in 22 adult cats. We implanted an array microelectrodes into locations the sacral that involved micturition reflexes. effect microelectrode stimulation studied under light Propofol anesthesia at monthly intervals up 14 months. found electrical parasympathetic nucleus S(2) level or adjacent ventrolateral...

Traumatic spinal cord injury (SCI) produces lower urinary tract (LUT) dysfunction that has been studied in surgical transection models. Our aim was to assess LUT functional deficit a clinically relevant model of incomplete SCI investigate how partial preservation supraspinal connections might affect dysfunction. Standardized weight-drop contusion (10 g × 2.5 cm) or complete transection, produced at T8 female Sprague-Dawley rats. Behavioral tests were used hind limb sensorimotor function Day...

Our objective is to develop neural prostheses based on an array of microelectrodes implanted into the sacral spinal cord, that will allow persons with cord injuries regain control their bladder and bowels. For our chronic cat model, we have developed two microelectrode arrays, one type containing nine discrete activated iridium second utilizing silicon substrate probes multiple electrode sites each probe. Both types can elicit increase in pressure within urinary more than 40-mm Hg and/or...

Abstract The biologically derived hydrogel Matrigel (MG) was used to coat a Parylene‐based sheath intracortical electrode act as mechanical and biological buffer well matrix for delivering bioactive molecules modulate the cellular response improve recording quality. MG loaded with dexamethasone reduce immune together nerve growth factor (NGF) brain‐derived neurotrophic (BDNF) maintain neuronal density encourage ingrowth toward electrodes within sheath. Coating Parylene significantly improved...

The authors describe a compact non-invasive CMOS-circuit-based glucose monitor using millimeter-wave transmission for use on animal and human subjects. Using an earlier device, in vivo measurements were performed through the ear anesthetized animals correlated with blood concentration from test strips. In addition, millimeter wave absorption glucose-containing solutions was measured specialized liquid cells is shown to correlate separate vitro data. Design performance information CMOS...

Conus medullaris and/or cauda equina forms of spinal cord injury commonly result in a permanent loss bladder function. Here, we developed and repair rodent model to investigate whether surgical implantation avulsed lumbosacral ventral roots into the can promote functional recovery lower urinary tract. Adult female rats underwent sham surgery ( n = 6), bilateral L5–S2 root avulsion (VRA) 5), or VRA followed by an acute L6 S1 conus 6). At 12 weeks after operation, group demonstrated retention,...

This paper models in vivo neural signals and noise for extracellular spike detection. Although the recorded data approximately follow Gaussian distribution, they clearly deviate from white due to neuronal synchronization sparse distribution of energy. Our study predicts coexistence two components embedded dynamics, one exponential form (noise) other power (neural spikes). The prediction has been confirmed experiments sequences hippocampus, cortex surface, spinal cord; both acute long-term...

A fabrication method for cuff electrodes to interface small nerves was developed. Medical grade silicone rubber conforms the body of and insulation wires, platinum used as metal embedded wiring contacts. Planar electrode arrays where fabricated using a picosecond laser then positioned into carrying tube provide third dimension with desired inner diameter (Ø 0.3-0.5 mm). The post preparation cuffs after structuring allows stable self-closing flap that insulates opening slit without need extra...

We present versatile multifunctional programmable controller with bidirectional data telemetry, implemented using existing commercial microchips and standard Bluetooth protocol, which adds convenience, reliability, ease-of-use to neuroprosthetic devices. Controller, weighing 190 g, is placed on animal's back provides sustained telemetry rate of 500 kb/s , allowing real-time control stimulation parameters viewing acquired data. In continuously-active state, consumes approximately 420 mW...

Investigations on the biological impact of low levels millimetre-wave energy date back to first experiments generation and detection these high-frequency signals by Sir Jagadis Chunder Bose at end 19th century. Slightly more than a hundred years later, transmission has become ubiquitous commercial reality. Despite widespread use transmitters for communications, radar even non-lethal weapons systems, only handful researchers have funded programmes focusing interactions with systems. As such,...

The authors present the first in vivo measurements of L-Glucose and D-Glucose concentrations using millimeter waves. Employing direct injection solutions into rat jugular vein, we have been able to correlate immediate changes blood glucose readings with transmission loss through ears anesthetized rats at Ka band (27-40 GHz). sensed changing D-glucose levels are shown track values, but a delay approximately 10-15 minutes, which may be due cellular uptake. Surprisingly, L-glucose,...