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1. Flexible, self-powered sensors for estimating human head kinematics relevant to concussions

   https://doi.org/10.1038/s41598-022-12266-6  

   Dsouza, Henry; Pastrana, Juan; Figueroa, José; Gonzalez-Afanador, Ian; Davila-Montero, Bianca M.; Sepúlveda, Nelson (June 2022, Scientific Reports)

   Abstract The present work demonstrates the development of a flexible, self-powered sensor patch that can be used to estimate angular acceleration and angular velocity, which are two essential markers for predicting concussions. The device monitors the dynamic strain experienced by the neck through a thin, polypropylene-based ferroelectret nanogenerator that produces a voltage pulse with profile proportional to strain. The intrinsic property of this device to convert mechanical input to electrical output, along with its flexibility and$$\sim$$ $\sim$100$$\mu$$ $\mu$m thickness makes it a viable and practical device to be used as a wearable patch for athletes in high-contact sports. After processing the dynamic behavior of the produced voltage, a correspondence between the electric signal profile and the measurements from accelerometers integrated inside a human head and neck substitute was found. This demonstrates the ability of obtaining an electronic signature that can be used to extract head kinematics during collision, and creates a marker that could be used to detect concussions. Unlike accelerometer-based current trends on concussion-detection systems, which rely on sensors integrated in the athlete’s helmet, the flexible patch attached to the neck would provide information on the dynamics of the head movement, thus eliminating the potential of false readings from helmet sliding or peak angular acceleration. 

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2. Mechanistic basis of propofol-induced disruption of kinesin processivity

   https://doi.org/10.1073/pnas.2023659118  

   Dutta, Mandira; Gilbert, Susan P.; Onuchic, José N.; Jana, Biman (January 2021, Proceedings of the National Academy of Sciences)

   Propofol is a widely used general anesthetic to induce and maintain anesthesia, and its effects are thought to occur through impact on the ligand-gated channels including the GABA_Areceptor. Propofol also interacts with a large number of proteins including molecular motors and inhibits kinesin processivity, resulting in significant decrease in the run length for conventional kinesin-1 and kinesin-2. However, the molecular mechanism by which propofol achieves this outcome is not known. The structural transition in the kinesin neck-linker region is crucial for its processivity. In this study, we analyzed the effect of propofol and its fluorine derivative (fropofol) on the transition in the neck-linker region of kinesin. Propofol binds at two crucial surfaces in the leading head: one at the microtubule-binding interface and the other in the neck-linker region. We observed in both the cases the order–disorder transition of the neck-linker was disrupted and kinesin lost its signal for forward movement. In contrast, there was not an effect on the neck-linker transition with propofol binding at the trailing head. Free-energy calculations show that propofol at the microtubule-binding surface significantly reduces the microtubule-binding affinity of the kinesin head. While propofol makes pi–pi stacking and H-bond interactions with the propofol binding cavity, fropofol is unable to make a suitable interaction at this binding surface. Therefore, the binding affinity of fropofol is much lower compared to propofol. Hence, this study provides a mechanism by which propofol disrupts kinesin processivity and identifies transitions in the ATPase stepping cycle likely affected. 

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3. Head motion classification using thread-based sensor and machine learning algorithm

   https://doi.org/10.1038/s41598-021-81284-7  

   Jiang, Yiwen; Sadeqi, Aydin; Miller, Eric L.; Sonkusale, Sameer (December 2021, Scientific Reports)

   null (Ed.)

   Abstract Human machine interfaces that can track head motion will result in advances in physical rehabilitation, improved augmented reality/virtual reality systems, and aid in the study of human behavior. This paper presents a head position monitoring and classification system using thin flexible strain sensing threads placed on the neck of an individual. A wireless circuit module consisting of impedance readout circuitry and a Bluetooth module records and transmits strain information to a computer. A data processing algorithm for motion recognition provides near real-time quantification of head position. Incoming data is filtered, normalized and divided into data segments. A set of features is extracted from each data segment and employed as input to nine classifiers including Support Vector Machine, Naive Bayes and KNN for position prediction. A testing accuracy of around 92% was achieved for a set of nine head orientations. Results indicate that this human machine interface platform is accurate, flexible, easy to use, and cost effective. 

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4. Passive neck brace for surgeons

   https://doi.org/10.1111/nyas.15308  

   Yang, Zixiao; Sathe, Tejas S; Shah, Meghal; Shah, Jay Hemant; Hu, David L (April 2025, Annals of the New York Academy of Sciences)

   Abstract A surgeon peers downward into a body cavity when operating. Holding this position for hours across weeks, months, and years may lead to neck pain and musculoskeletal disorders. We were inspired by ungulates such as giraffes and horses, which use dorsal‐ventral flexion to graze for 9–14 h per day without perceivable neck pain. Ungulates evolved a strong nuchal ligament that relieves neck muscles by stretching to support some of the weight of the head during grazing or running. In contrast, humans evolved an upright posture, and like many primates, have a reduced nuchal ligament. The goal of this study is to use the nuchal ligament as inspiration for a neck brace that passively supports the weight of the head while still permitting lateral flexion, ventral‐dorsal flexion, and rotation. We assembled a prototype using an elastic band, headband, and back posture corrector. Our device augments the human nuchal ligament by using a stiff material and greater mechanical advantage. By our calculations, flexing the head ventrally 40 degrees when wearing the brace reduces the torque applied by neck muscles by 21%. Our device is a proof‐of‐concept that a bioinspired device can offload neck muscular tension and prevent injury. 

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5. Evaluation of a novel 8-channel RX coil for speech production MRI at 0.55 T

   https://doi.org/10.1007/s10334-022-01036-0  

   Muñoz, Felix; Lim, Yongwan; Cui, Sophia X; Stark, Helmut; Nayak, Krishna S (July 2023, Magnetic Resonance Materials in Physics, Biology and Medicine)

   Objective Speech production MRI benefits from lower magnetic fields due to reduced off-resonance effects at air-tissue interfaces and from the use of dedicated receiver coils due to higher SNR and parallel imaging capability. Here we present a custom designed upper airway coil for 1H imaging at 0.55 Tesla and evaluate its performance in comparison with a vendor-provided prototype 16-channel head/neck coil. Materials and methods Four adult volunteers were scanned with both custom speech and prototype head–neck coils. We evaluated SNR gains of each of the coils over eleven upper airway volumes-of-interest measured relative to the integrated body coil. We evaluated parallel imaging performance of both coils by computing g-factors for SENSE reconstruction of uniform and variable density Cartesian sampling schemes with R = 2, 3, and 4. Results The dedicated coil shows approximately 3.5-fold SNR efficiency compared to the head–neck coil. For R = 2 and 3, both uniform and variable density samplings have g-factor values below 1.1 in the upper airway region. For R = 4, g-factor values are higher for both trajectories. Discussion The dedicated coil configuration allows for a significant SNR gain over the head–neck coil in the articulators. This, along with favorable g values, makes the coil useful in speech production MRI. 

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