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The Neuromuscular Junction
Published in Nassir H. Sabah, Neuromuscular Fundamentals, 2020
Normal operation of the NMJ can be interfered with at several levels, including synthesis and release of ACh at the presynaptic terminal, blocking of ACh channels, desensitization of ACh receptors, or their damage. Moreover, a slow, sustained depolarization of the endplate can inhibit generation of the muscle AP in neighboring muscle membrane through accommodation of the AP mechanism (Section 3.3.2). Myasthenia gravis, derived from the Greek for severe muscle weakness, is a disease in which neuromuscular transmission is impaired. Some forms of the disease are due to genetic mutations, but the most prevalent form of the disease is autoimmune in which the body’s immune system produces antibodies that block, alter, or destroy ACh receptors. Moreover, the normal infolding at the endplate is reduced and the synaptic cleft is enlarged. The overall effect is a drastic reduction of the epp to around the threshold for the muscle AP or even less. The disease usually affects the eyelid muscles first, causing drooping eyelids. It can also affect the eye muscles, resulting in inability to move the eyes. The effect of depression of neuromuscular transmission in other parts of the body due to the aforementioned factors ranges from muscle weakness to muscle paralysis, including muscle fatigue, that is, progressive weakness of a muscle during activity. Symptoms are partially relieved by drugs that inhibit AChE, which enhances the action of ACh. Respiratory failure can occur if the breathing muscles are severely affected.
Effect of exertion on blink reflex parameters in Division I football athletes
Published in Cogent Engineering, 2023
Dena P. Garner, Patrick D. Sparks, Haley M. Chizuk, Mohammad N. Haider
A novel device, referred to as the EyeStat (Blinkcns, Charleston, SC), is an FDA-approved device developed to measure changes in the blink reflex when comparing baseline and post-head impact responses. Data from the EyeStat suggest that the reflex associated with the blink response results in an involuntary response from the subject, thereby providing objective autonomic nervous system data. (Paparella et al., 2022; Tsai et al., 2017). Previous blink reflex research, as measured with the EyeStat technology, cited significant differences in latency, differential latency, log time under the threshold, number of oscillations, lid excursion, and lid velocity (see below for definitions) between baseline and post-head impact individuals (Garner et al., 2018). Each of the responses identified by the EyeStat provide a reflexive, involuntary response to a stimulus. For example, latency demonstrates the time it takes for the stimulated eyelid to blink after a stimulus, while differential latency is the contralateral eyelid response after the blinking is initiated in the stimulated eye. Thus, differences in these measured parameters from a reflexive response may provide clarity on changes in brain function as the blink reflex provides information from the cranial nerves V and VII, including connections to the pons and medulla, resulting in an extensive network within the brain (Esteban, 1999; Jerath & Kimura, 2019).
A Deep Learning-based System for Detecting Anemia from Eye Conjunctiva Images Taken from a Smartphone
Published in IETE Technical Review, 2023
Bijit Basumatary, Rahul Shukla, Rakesh Kumar, Bodhisatwa Das, Ashish Kumar Sahani
We used the Kobotoolbox for the data collection from the field. The Kobocollect app can be used to collect data without the internet and send the collected data later to the project when the internet is available [18]. We collected the images of left and right eye conjunctiva and the information of gender, age, and the Hb value in the anemia data collection project. There were 160 anemic cases and 140 non-anemic cases of different ages. One hundred six of the anemic cases were female, and the remaining 54 were male; among the non-anemic cases, 121 were male, and 19 were female. Detail about the distribution of the dataset is given in Table 1. We also used some open-sourced eyes images with conjunctiva parts available on the internet, specifically for segmentation models. The study was ethically approved by the IEC of Dayanand Medical College and Hospital Ludhiana (Reference No: IEC 2021–655 Dated: 31-May-2021). We consider people of mixed age groups, gender and ethnicity, and eliminate people with an eye infection, extreme drinking and smoking habits and medical conditions. We asked people to sit under proper lighting and pull the lower eyelid from the middle with their index finger so the eye conjunctiva region could be adequately visible, as shown in Figure 2(a). We instruct people to look upward to avoid the disturbance of eyelashes. We avoided the shadow effect on the conjunctiva part as it may cause the miscalculation of the pixels.
A New Design of Iris Recognition Using Hough Transform with K-Means Clustering and Enhanced Faster R-CNN
Published in Cybernetics and Systems, 2022
Gorla Babu, Abdul Khayum Pinjari
Once the iris localization process is completed, the pixels of the images are identified using the local grey level analysis. The pixels around the iris circle are detected by considering an automated boundary refinement method. It considers three processes as given here. “Detection of lower half iris”: It is affected by the eyelid, and eyelash, and therefore there is a need to detect them. It is done with the process of sector thresholding to identify the lower half area.“Detection of upper half iris”: This region is deeply affected through the noise in case of the eyelash and shadow that is done by the sectorial thresholding for the detection. In addition, to provide an upper half masking, the reflection from the eye region is removed.“Separation of the shadow, eyelid, and eyelash regions”: lastly, these regions are separated from the segmented regions through careful attention in the upper half iris region. Finally, the segmented images using the proposed HT-KMC approach are represented as