A simulation environment for studying transcutaneous electrotactile stimulation

Transcutaneous electrical stimulation of the stellate ganglion: A case report on its application in treating carotid sinus syndrome

RATIONALE

Syncope is a common condition in emergency departments, posing a diagnostic challenge due to its multifactorial nature. Among the potential causes, carotid sinus hypersensitivity leading to carotid sinus syndrome (CSS) is a significant consideration that can severely impact patient quality of life. Despite its importance, establishing effective treatment methods for CSS has been difficult.

PATIENT CONCERNS

A 43-year-old male presented with recurrent episodes of syncope, which significantly affected his daily life and well-being.

DIAGNOSES

After a thorough evaluation, the patient was diagnosed with CSS, a condition that can be difficult to pinpoint and requires specialized diagnostic procedures to confirm.

INTERVENTIONS

The patient was treated with stellate ganglion block therapy, a targeted intervention aimed at addressing the underlying cause of CSS. This treatment was administered over a 12-day period.

OUTCOMES

Following the treatment, the patient's symptoms showed gradual improvement, and he was discharged after meeting the clinical cure criteria. During a 7-month follow-up, he remained symptom-free.

LESSONS

The case highlights the effectiveness of transcutaneous stellate ganglion block therapy in treating CSS. It suggests that further research and clinical trials are needed to validate this treatment's efficacy, potentially offering a new therapeutic option for patients suffering from CSS.

Development of a Tactile Actuator with Non-Contact and Trans-Object Characteristics Using a Time-Varying Magnetic Field

A non-contact tactile stimulation system using a time-varying magnetic field was developed. The system comprises a control unit, power unit, output unit, and actuator. The control unit adjusts stimulation parameters, particularly the signal intensity and frequency. The power unit produces high voltages for generating the magnetic field, whereas the output unit transmits the energy generated according to the signal from the control unit to the actuator. A spiral coil actuator generates the magnetic field. To validate the effectiveness of the system, preliminary experiments on 10 male adults without neurological disorders (23.2 ± 3.05 years) were conducted. Magnetic field stimuli were presented to the right palm of the subjects at three different frequencies (10, 30, and 50 Hz), and corresponding electroencephalogram (EEG) signals were measured simultaneously. Event-related potential (ERP) analysis showed that N100 and P300 components were identified in somatosensory areas. Subjective evaluations revealed that feelings such as “tingling,” “trembling,” “tapping,” and “percussing” were induced. Moreover, as the stimulus frequency changes, differences may occur in induced feeling. The system uses a time-varying magnetic field, which not only induces tactile stimulation without contact but also has trans-object characteristics that can present tactile sensations, even when there is an obstacle between an actuator and skin.

Mediating different-diameter Aβ nerve fibers using a biomimetic 3D TENS computational model

BACKGROUND

Significant progress has been made over the last 50 years in the design, development and testing of transcutaneous electrical nerve stimulation (TENS) in mediating different levels of tactile sensations. However, without knowing how best to stimulate the nerve fibers, the elicited sensation quality will always remain poor and unnatural.

NEW METHOD

A new biomimetic 3D TENS computational model is developed to quantify the neural activation mechanism with varied surface electrodes. This model includes seven-layered anatomical structure of the forearm and biophysically-detailed myelinated Aβ fibers. The Aβ-fiber diameters from 1.5 - 7.5 μm were randomly distributed beneath the skin to mimic the physiologically-realistic fiber population. The arithmetic averaging algorithm and Gaussian filter were adopted to identify the sensation center and to quantify sensation intensities under different stimulation conditions.

RESULTS

Fibers larger than 4.5 μm can usually be activated producing tactile sensations such as light touch, pressure, buzz, and vibration. While, fibers with diameters of 3.5 and 3 μm can only be excited at uncomfortable numb and pain sensations. The resulted modelling predictions match the recent psychophysical experimental data.

COMPARISON WITH EXISTING METHOD(S)

The new TENS model is more physiologically-realistic by introducing a detailed morphological information and key ionic mechanisms in nerve fibers.

CONCLUSIONS

Our results indicate that TENS may be a promising method to target functionally-distinct neural pathways in an effort to improve the elicited tactile sensations quality with electrical stimulation. This work provides a promising platform of discovering neural mechanisms under TENS.