Even the mundane action of swallowing requires a well-coordinated dance of more than 30 mouth muscles. Loss of function from even one of these, due to illness or injury, can be extremely debilitating. For these people, nerve stimulation offers a ray of hope to regain some of their lost oral function.
In a new study, researchers at Texas A&M University have delineated the minimum size of electrical currents needed to provide sensation to different parts of the mouth. The researchers said their study is a first but vital step toward creating electrical stimulation implants that can restore essential intraoral functions that are lost due to nerve or brain damage.
The results of the study are published in the journal IEEE transactions in biomedical engineering.
Many essential bodily functions are coordinated by the nervous system by sensorimotor feedback loops. As its name suggests, these neural circuits implies that the brain interprets incoming signals from sensory nerves and then commanding the motor nerves to execute a certain movement. Thus, for example, sensorimotor loops play a vital role in voluntary functions, such as walking or holding an object, and in involuntary movements, such as sneezing or blinking.
Inside the mouth, also known as the intraoral cavity, there is a rich contribution of both sensor and motor nerves. In particular, the sensorimotor nerves in the soft palate and language coordinate various intraoral movements related to swallowing, speech, and breathing. Therefore, damage to sensory or motor nerve fibers due to a neurotrauma or disease can compromise these essential functions, reducing the quality of life of those affected.
Electrical nerve stimulation can help initiate nerves into action, just as a pacemaker can electrically stimulate the nerves in the heart, causing the heart muscle to contract. But, unlike a pacemaker, no details have been investigated about the frequency and amplitude of electrical currents needed for proper stimulation of different parts of the mouth.
“Electrical stimulation can be modulated nerves the currents or action potentials, which are the mode of communication to the brain, “said Dr. Hangue Park, an assistant professor in the Department of Electrical and Computer Engineering. then it can cause undesirable effects or it may not stimulate anything.”
To investigate the minimum stimulation currents required, Park and his team introduced small metal electrodes into a standard dental retention. These electrodes were placed on subjects to stimulate their soft palate or the side and tip of the tongue, which receive a rich supply of sensory nerves. For each of these locations, the researchers slowly changed the amplitude of the stimulation current, keeping the frequency fixed. Subjects were then asked to report when they had just felt a sensation and when the sensation was uncomfortable. They then repeated the same experiment to obtain a higher current frequency.
After collecting their data, the team determined the thresholds of perception and average discomfort for the tongue and soft palate. In addition, they produced an equivalent circuit of the intraoral cavity to duplicate the electrical properties of this area. This circuit, according to researchers, may help study the effects of electrical stimulation no connection no need human subjects.
The researchers noted that the next steps would be to electrically stimulate the intraoral region and investigate how these simulations change chewing, swallowing, and other behaviors.
“Sensorimotor systems can be extremely vulnerable to damage caused by neuronal defects, aging, and neurodegenerative diseases,” Park said. “In this study, we have begun to lay the groundwork for electrically stimulating parts of the mouth that control involuntary and voluntary movements. Our work is a seminal study and is important so that we can, in the near future, help people who are ‘they face enormous challenges in doing everyday tasks that we take for granted.’
Beomhee Park et al, Electrical characterization of the tongue and soft palate using the clustered model for intraoral neuromodulation, IEEE transactions in biomedical engineering (2021). DOI: 10.1109 / TBME.2021.3070867
Texas A&M University
Citation: Research lays the groundwork for restoring lost oral functions with pacemaker-like devices (2021, June 30) retrieved June 30, 2021 at https://medicalxpress.com/news/2021-06-groundwork-lost- oral-functions-pacemaker-like .html
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