RESUMEN
The Department of Transport in the United Kingdom recorded 25,080 motor vehicle fatalities in 2019. This situation stresses the need for an intelligent transport system (ITS) that improves road safety and security by avoiding human errors with the use of autonomous vehicles (AVs). Therefore, this survey discusses the current development of two main components of an ITS: (1) gathering of AVs surrounding data using sensors; and (2) enabling vehicular communication technologies. First, the paper discusses various sensors and their role in AVs. Then, various communication technologies for AVs to facilitate vehicle to everything (V2X) communication are discussed. Based on the transmission range, these technologies are grouped into three main categories: long-range, medium-range and short-range. The short-range group presents the development of Bluetooth, ZigBee and ultra-wide band communication for AVs. The medium-range examines the properties of dedicated short-range communications (DSRC). Finally, the long-range group presents the cellular-vehicle to everything (C-V2X) and 5G-new radio (5G-NR). An important characteristic which differentiates each category and its suitable application is latency. This research presents a comprehensive study of AV technologies and identifies the main advantages, disadvantages, and challenges.
RESUMEN
A 60-year-old woman with diabetes mellitus presented to the emergency department (ER) with complaints of lower limb weakness, preceded by diarrhea. She complained of sweating and palpitations. There was no fever, cough, trauma, seizures, or headache. There was global weakness in all four limbs with absent reflexes and hypotonia. Examination of cranial nerves, the sensory system, and other systems was normal. Guillain-Barre syndrome (GBS) was suspected, but due to the patient's co-morbidities, treatment was withheld for 24 hours and the patient was kept under observation. Medical consultation was sought and thyroid function tests were ordered which showed thyroid-stimulating hormone (TSH) 0.019 uIU/ml (normal: 0.35-4.94 uIU/ml), free triiodothyronine (T3) 11.94 pg/ml (normal: 2.0-4.4 pg/ml), and free thyroxine (T4) >5 ng/dl (normal: 0.70-1.48 ng/dl). Thyroid storm was suspected and she was treated with hydrocortisone, propylthiouracil, Lugol iodine, and beta-blocker and her symptoms improved in 10 days with resolution of the weakness, confirming the diagnosis. Besides highlighting this association, this report demonstrates the importance of conducting thyroid function tests in patients presenting with axonal neuropathy. In patients having weakness in all four limbs and presenting with multiple comorbidities, we need to exclude medical reasons before starting treatment for GBS, such as in our case where it was thyrotoxicosis.