The waveform most frequently used is a charge balanced, symmetric, biphasic stimulation pulse, where a square cathodic pulse is followed by an anodic pulse of equal amplitude. Furthermore, the useful stimulation waveform durations are usually very short (10 Ојs to 100 Ојs). ICMS requires relatively high voltages (50вЂ“100 V) when high impedance (0.5вЂ“2MО©) electrodes are used. Intracortical microstimulation (ICMS) poses a number of exacting requirements on the experimental system. Here we describe our custom multichannel microstimulator that enabled these BMBIs. More recently, our laboratory has demonstrated closed-loop BMBI control for delivering artificial texture feedback through ICMS, where precise, rapid, and low-artifact ICMS control was essential to give feedback to the monkey without interfering with recording periods. In experiments conducted in our laboratory, we utilized temporal patterns of cortical microstimulation to create an artificial somatosensory input for the BMI that enacted arm reaching movements. Microstimulation has been introduced as a sensory loop in brain-machine-brain interfaces (BMBIs), systems that both translate brain activity into commands to artificial actuators and deliver information to the brain in the form of microstimulation of sensory areas. This property of bioelectrical stimulation has attracted the attention of neural engineers as the key component of sensory neural prosthetics for the restoration of sensation in patients suffering from sensory disabilities. In particular, microstimulation can produce or bias sensations. Numerous studies have shown that electrical microstimulation of neural circuits by injecting small currents from an electrode tip into the nervous tissue may evoke a variety of effects that are often similar to the functional contribution of the stimulated area. With the realized device and standard recording hardware - without active artifact rejection - we are able to observe stimulus artifacts of less than 2 ms in duration. As many applications of this technique, including BMBIs, require recording as well as stimulation, we pay careful attention to isolation of the stimulus channels and parasitic current injection. Here we detail the design of a high-side, digitally current-controlled biphasic, bipolar microstimulator, and describe the validation of the device in vivo.

ICMS also holds promise for enabling brain-machine-brain interfaces (BMBIs) by directly writing information into the brain. In the central nervous system, intracortical microstimulation (ICMS) has been shown to be an effective method for inducing or biasing perception, including visual and tactile sensation. Electrical stimulation of nervous tissue has been extensively used as both a tool in experimental neuroscience research and as a method for restoring of neural functions in patients suffering from sensory and motor disabilities.

Matlab ed overman