Unsupervised and scalable low train pathology detection system based on neural networks.

Currently, there exist different technologies applied in the world of medicine dedicated to the detection of health problems such as cancer, heart diseases, etc. However, these technologies are not applied to the detection of lower body pathologies. In this article, a Neural Network (NN)-based system capable of classifying pathologies of the lower train by the way of walking in a non-controlled scenario, with the ability to add new users without retraining the system is presented. All the signals are filtered and processed in order to extract the Gait Cycles (GCs), and those cycles are used as input for the NN. To optimize the network a random search optimization process has been performed. To test the system a database with 51 users and 3 visits per user has been collected. After some improvements, the algorithm can correctly classify the 92% of the cases with 60% of training data. This algorithm is a first approach of creating a system to make a first stage pathology detection without the requirement to move to a specific place.

Wearable Transcranial Ultrasound System for Remote Stimulation of Freely Moving Animal.

OBJECTIVE: Transcranial focused ultrasound (tFUS) has drawn considerable attention in the neuroscience field as a noninvasive approach to modulate brain circuits. However, the conventional approach requires the use of anesthetized or immobilized animal models, which places considerable restrictions on behavior and affects treatment. Thus, this work presents a wireless, wearable system to achieve ultrasound brain stimulation in freely behaving animals. METHODS: The wearable tFUS system was developed based on a microcontroller and amplifier circuit. Brain activity induced by tFUS was monitored through cerebral hemodynamic changes using near-infrared spectroscopy. The system was also applied to stroke rehabilitation after temporal middle cerebral artery occlusion (tMCAO) in rats. Temperature calculations and histological results showed the safety of the application even with prolonged 40 min sonication. RESULTS: The output ultrasonic wave produced from a custom PZT transducer had a central frequency of 457 kHz and peak to peak pressure of 426 kPa. The device weight was 20 g, allowing a full range of motion. The stimulation was found to induce hemodynamic changes in the sonicated area, while open-field tests showed that ultrasound applied to the ipsilateral hemisphere for 5 consecutive days after the stroke facilitated recovery. CONCLUSION: The wearable tFUS system has been designed and implemented on moving rats. The results showed the ability of device to cause both short- and long lasting effects. SIGNIFICANCE: The proposed device provides a more natural environment to investigate the effects of tFUS for behavioral and long-term studies.

Mobile Wireless Low-intensity Transcranial Ultrasound Stimulation System for Freely Behaving Small Animals.

Transcranial ultrasound stimulation (tUS) is a promising noninvasive approach to modulate brain circuits. While low-intensity tUS is putatively safe and has already been used for human participants, pre-clinical studies that aim to determine the effects of tUS on the brain still need to be carried out. Conventional tUS stimulation, however, requires the use of the anesthetized or immobilized animal model, which can place considerable restrictions on behavior. Thus, this work presents a portable, low cost, wireless system to achieve ultrasound brain stimulation in freely behaving animals. The tUS system was developed based on a commercial 16 MHz microcontroller and amplifier circuit. The acoustic wave with a central frequency of 450 kHz was generated from a 5mm PZT with a peak pressure of 426 kPa. The wireless tUS with a total weight of 20 g was placed on the back of the rat allowing the animal a full range of unimpeded motion. The mobile ultrasound system was able to induce a robust ear movement as a response to stimulation of the motor cortex. The outcome demonstrates the ability of wireless tUS to modulate the brain circuit of a freely behaving rat. The portability of the whole system provides a more natural environment for investigating the effect of tUS on behavior and chronic studies.