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Thomas Willis, the father of neurology, about 400 years ago said “To explicate the uses of the brain seems as difficult a task as to paint the Soul, of which it is commonly said, that it understands all things but itself.” During this long period, considerable attempts have been made to improve extraordinary brain capabilities in the treatment of several diseases and disorders. Now, it is understood that neuromodulation as well as neural interface recording and stimulation can effectively influence the development of therapeutic and diagnostic approaches [Citation1]. These improvements have been mostly centered on neurological disorders, pain, managing the immune system in inflammatory sicknesses, and various tumor diseases.
Two main methods that are mostly used for stimulating the brain and spinal cord are named deep brain stimulation (DBS) and spinal cord stimulation (SCS). In which, several electrodes are implanted into the specified brain or spinal cord regions [Citation2,Citation3]. These terminals can produce small electrical impulses to regulate unusual brain activities or pains. Moreover, they can adjust the chemical disbalances of the brain that are responsible for various disabilities. To perform the whole procedure, a battery-operated neurotransmitter as a generator is required to be placed under the skin.
The advances in DBS and SCS functions are seriously dependent on the progress in technologies. They can provide a better design for devices to be handed to patients in their activities. DBS and SCS have been applied for the treatment of movement disorders such as dystonia, Parkinson disease, tremor, multiple sclerosis, pain syndromes, and psychiatric conditions.
Although various systems utilize closed-loop structures with more emphasis on practicability, developing high-accuracy devices is required. To overcome possible challenges, various researchers in the fields of material chemistry science, bioelectronic medicine, software programming, engineering physics, and biology in collaboration with neurosurgeons try to decrease the side effects on the patients by declining the technical problems.
Neuromorphic chips as a new generation of autonomous systems are hopeful technology for implanted body-machine. With the mimicking co-location of logic and memory, hyper-connectivity, and parallel processing in the human brain, neuromorphic computing architectures can also provide a guarantee for a significant decrease in power using by physically imitating neurons and synapses at the tiny device [Citation4]. Neuromorphic computing depends on common electronic materials, especially silicon-based complementary metal–oxide– semiconductor (CMOS) spiking neural networks. To improve the neural decoding efficiency and diagnostic accuracy, the brain implants should be contained a large number (100–1000) of electrodes. This leads to an increase in the complexity of the obtained data and consequently, it is required to use the complicated artificial intelligence (AI) process. Although silicon is an ordinary probe material due to its integrated capability with CMOS, it has low biocompatibility because of its rigidity after implantation and also keen edges. Therefore, utilizing nanomaterials such as carbon-based nanostructures in the generation of biocompatible probes is so remarkable for having more signal admission locations, less implantation error, minimum thickness, and the least noise [Citation5]. Moreover, the prosperity in the stimulation is relevant to the accurate position of electrodes and modality of stimulation. These kinds of challenges obviously show that it is essential to develop more effective devices to not be electrical ones. The other kind of non-electrical technique can be optical DBS.
Optogenetics is a photostimulation method that integrates a combination of genetic and optical detection engineering techniques to stimulate brain tissue. This elegant technique has been appointed as a promising substitution for customary electrostimulation through controlling and monitoring the biological operation of tissues. In which, specific neurons can be genetically modified by the lentiviral gene delivery originating from a light-sensitive protein. These neurons can be further stimulated by light with a certain wavelength [Citation6].
In the clinic, the feasibility of implanting electrode arrays with a syringe and further connection to decoders and actuators authorize the stimulation of neurons with a superior degree of precision. For performing this procedure, robot-assisted surgery/robotic surgery can aid neurosurgeons to carry out implant surgeries with more accuracy and better control than the traditional methods.
Furthermore, neuroscience has improved in clinical applications with immersive visualization technologies such as virtual reality (VR) and augmented reality (AR). VR offers digital modulation schemes from real-life environments to assess surgical performance and quantify surgeon proficiency. Whereas AR provides real-time visual navigation to improve treatment tracking with the information gathered by video analysis. These VR technologies evolve potentials for increasing the efficiency of treatment delivery, surgical plan, track navigation, and lowering the risk of the training environment. On one side, VR/AR integration has the great possibility to couple with robotic devices for remotely modulating functions. This provides extending sensors and controlling tools. On the other side, the convergence between VR and AI can develop the Virtual Operative Assistant to enhance the skills of neurosurgeons [Citation7]. Also, medical robotic technologies using AI can form robotic-assisted surgery to perform surgical planning with the lowest error and risks. The combination of all these elements enables us to perform automated immersive experiences during neurosurgical simulation, surgical planning, and better clinical care.
In a short look, the future of advancement in neuroscience for the next 10 years is impressively influenced by high-tech improvement. In the future horizon, neuroscience, neurology, and neurosurgery for the enhancement of better health care in safe clinical procedures require progressive stimulators, extended reality technologies, powerful computational machine learning methods corresponding with AI, and medical robotic devices with high-speed internet. In addition, the innovative progress in this area provides significant advantages consisting of the development of low-cost, biocompatible, flexible, energy-efficient, and long-time usability implant nanochips. Accordingly, neuromodulation will be a key treatment for various diseases and disorders; or probably will develop to enhance the physical ability of healthy people. These researches can be generalized to neural stimulation to drive alterations in the microbiome in states of dysbiosis and to improve the function of targeted organs and health. Eventually, it can be expected the growth in the therapies for various diseases relies on neurostimulators. We could wait or have a role in this huge progression.
Disclosure statement
No potential conflict of interest was reported by the authors.
References
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- Mekhail N, Levy RM, Deer TR, et al. Long-term safety and efficacy of closed-loop spinal cord stimulation to treat chronic back and leg pain (evoke): a double-blind, randomised, controlled trial. The Lancet Neurology. 2020;19(2):123–134.
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