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PloS One 2023Position determination is a critical technical challenge to be addressed in the unmanned and intelligent advancement of crane systems. Traditional positioning...
Position determination is a critical technical challenge to be addressed in the unmanned and intelligent advancement of crane systems. Traditional positioning techniques, such as those based on magnetic grating or encoders, are limited to measuring the positions of the main carriage and trolley. However, during crane operations, accurately determining the position of the load becomes problematic when it undergoes swinging motions. To overcome this limitation, this paper proposes a novel Ultra-Wide-Band (UWB) positioning method for unmanned crane systems, leveraging the Snake Optimizer Long Short-Term Memory (SO-LSTM) framework. The objective is to achieve real-time and precise localization of the crane hook. The proposed method establishes a multi-base station and multi-tag UWB positioning system using a Time Division Multiple Access (TDMA) combined with Two-Way Ranging (TWR) scheme. This system enables the acquisition of distance measurements between the mobile tag and UWB base stations. Furthermore, the hyperparameters of the LSTM network are optimized using the Snake Optimizer algorithm to enhance the accuracy and effectiveness of UWB positioning estimation. Experimental results demonstrate that the SO-LSTM-based positioning method yields a maximum positioning error of 0.1125 meters and a root mean square error of 0.0589 meters. In comparison to conventional approaches such as the least squares method (LS) and the Kalman filter method (KF), the proposed SO-LSTM-based positioning method significantly reduces the root mean square error (RMSE) by 63.39% and 58.01%, respectively, while also decreasing the maximum positioning error (MPE) by 60.77% and 52.65%.
Topics: Algorithms; Intelligence; Memory, Long-Term; Motion; Stretchers
PubMed: 37910546
DOI: 10.1371/journal.pone.0293618 -
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi =... Dec 2023For the transportation process of rescuing wounded personnel on naval vessels, a new type of shoulder type exoskeleton stretcher for individual soldier was designed in...
For the transportation process of rescuing wounded personnel on naval vessels, a new type of shoulder type exoskeleton stretcher for individual soldier was designed in this paper. The three-dimensional model of the shoulder type exoskeleton stretcher for individual soldier was constructed using three dimensional modeling software. Finite element analysis technique was employed to conduct statics simulation, modal analysis, and transient dynamics analysis on the designed exoskeleton stretcher. The results show that the maximum stress of the exoskeleton stretcher for walking on flat ground is 265.55 MPa, which is lower than the allowable strength of the fabrication material. Furthermore, the overall deformation of the structure is small. Modal analysis reveals that the natural frequency range of the exoskeleton stretcher under different gait conditions is 1.96 Hz to 28.70 Hz, which differs significantly from the swing frequency of 1 Hz during walking. This indicates that the designed structure can effectively avoid resonance. The transient dynamics analysis results show that the maximum deformation and stress of exoskeleton stretcher remain within the safety range, which meets the expected performance requirements. In summary, the shoulder type exoskeleton stretcher for individual soldier designed in this study can solve the problem of requiring more than 2 people to carry for the existing stretcher, especially suitable for narrow spaces of naval vessels. The research results of this paper can provide a new solution for the rescue of wounded personnel on naval vessels.
Topics: Humans; Stretchers; Military Personnel; Shoulder; Exoskeleton Device; Walking; Gait; Biomechanical Phenomena
PubMed: 38151944
DOI: 10.7507/1001-5515.202306012 -
PloS One 2023Various rescue techniques are used for the prehospital transport of trauma patients. This study compares different techniques in terms of immobilization of the cervical...
BACKGROUND
Various rescue techniques are used for the prehospital transport of trauma patients. This study compares different techniques in terms of immobilization of the cervical spine and the rescue time.
METHODS
A wireless motion capture system (Xsens Technologies, Enschede, The Netherlands) was used to record motion in three-dimensional space and the rescue time in a standardized environment. Immobilization was performed by applying different techniques through different teams of trained paramedics and physicians. All tests were performed on the set course, starting with the test person lying on the floor and ending with the test person lying on an ambulance cot ready to be loaded into an ambulance. Six different settings for rescue techniques were examined: rescue sheet with/without rigid cervical collar (P1S1, P1S0), vacuum mattress and scoop stretcher with/without rigid cervical collar (P2S1, P2S0), and long spinal board with/without rigid cervical collar (P3S1, P3S0). Four time intervals were defined: the time interval in which the rigid cervical collar is applied (T0), the time interval in which the test person is positioned on rescue sheet, vacuum mattress and scoop stretcher, or long spinal board (T1), the time interval in which the test person is carried to the ambulance cot (T2), and the time interval in which the ambulance cot is rolled to the ambulance (T3). An ANOVA was performed to compare the different techniques.
RESULTS
During the simulated extrication procedures, a rigid cervical collar provided biomechanical stability at all angles with hardly any loss of time (mean angle ranges during T1: axial rotation P1S0 vs P1S1 p<0.0001, P2S0 vs P2S1 p<0.0001, P3S0 vs P3S1 p<0.0001; lateral bending P1S0 vs P1S1 p = 0.0263, P2S0 vs P2S1 p<0.0001, P3S0 vs P3S1 p<0.0001; flexion/extension P1S0 vs P1S1 p = 0.0023, P2S0 vs P2S1 p<0.0001). Of the three techniques examined, the scoop stretcher and vacuum mattress were best for reducing lateral bending in the frontal plane (mean angle ranges during T1: P2S1 vs P3S1 p = 0.0333; P2S0 vs P3S0 p = 0.0123) as well as flexion and extension in the sagittal plane (mean angle ranges during T2: P1S1 vs P2S1 p<0.0001; P1S0 vs P2S0 p<0.0001). On the other hand, the rescue sheet was clearly superior in terms of time (total duration P1S0 vs P2S0 p<0.001, P1S1 vs P2S1 p<0.001, P1S0 vs P3S0 p<0.001, P1S1 vs P3S1 p<0.001) but was always associated with significantly larger angular ranges of the cervical spine during the procedure. Therefore, the choice of technique depends on various factors such as the rescue time, the available personnel, as well as the severity of the suspected instability.
Topics: Humans; Immobilization; Motion Capture; Cervical Vertebrae; Rotation; Stretchers; Range of Motion, Articular; Biomechanical Phenomena
PubMed: 38015902
DOI: 10.1371/journal.pone.0292300 -
Carrying life and death: the daily routine of hospital stretcher bearers in the context of COVID-19.Ciencia & Saude Coletiva Oct 2023This article aims to analyze the daily work of stretcher bearers in a Federal Teaching and Research Hospital in the context of COVID-19, exploring the subjective aspects...
This article aims to analyze the daily work of stretcher bearers in a Federal Teaching and Research Hospital in the context of COVID-19, exploring the subjective aspects related to working in constant contact with death and the invisibility to which these workers are subjected. The proposed discussion stems from a more comprehensive qualitative investigation. The main methodological resource of the empirical research was the direct observation in the daily work that allowed one to capture nuances of the work in a dialectical analysis with the workers. The data obtained were analyzed from the perspective of Social Psychology of Work. Transience and invisibility were identified as important categories of analysis of this daily work, where the process of becoming a stretcher-bearer was marked by aspects of precariousness of work and vulnerability of the worker. Working in contact with death was also understood as a factor of invisibility, where the creation of bonds and humor appeared as a collective strategy to face the harshness of work. This article concluded by examining the importance of looking at the subjective aspects of the work carried out by stretcher bearers, as well as the expansion of research on the subject.
Topics: Humans; Stretchers; COVID-19; Hospitals
PubMed: 37878929
DOI: 10.1590/1413-812320232810.10292023 -
Clinical, Cosmetic and Investigational... 2023To explore the application value of adjustable skin stretchers for repairing skin wound defects.
OBJECTIVE
To explore the application value of adjustable skin stretchers for repairing skin wound defects.
METHODS
Twenty patients with skin defects were included in this study. The largest defect was measured to be 45.4 cm × 13.3 cm (length × width) and the smallest one was 4.4 cm × 3.2 cm (length × width). All patients were subjected to adjustable skin stretchers and the short- and long-term clinical efficacy was evaluated.
RESULTS
The wounds of all enrolled patients were healed completely except for one patient with a dorsal foot infection (the patient requested to return to the local county hospital for further treatment), with a total satisfaction of 100%. Postoperative 3-month follow-up showed scar formation, a little local hyperpigmentation, normal skin elasticity, and intact organs of involved cases, thus signifying the significant impact of adjacent joint activities.
CONCLUSION
Adjustable skin stretchers can accurately control the tension on wound margins, breaking the limitation of previous stretchers to provide objective quantitative indicators for clinical application. These stretchers are characterized by high use-value and are worth promoting.
PubMed: 37694193
DOI: 10.2147/CCID.S411870 -
Optics Express Sep 2023In soft X-ray free-electron laser (FEL) beamlines, variable-line-spacing (VLS) gratings are often used as dispersive components of monochromators and spectrometers due...
In soft X-ray free-electron laser (FEL) beamlines, variable-line-spacing (VLS) gratings are often used as dispersive components of monochromators and spectrometers due to their combined dispersion and focusing properties. X-ray FEL pulses passing through the VLS grating can result in not only transverse focusing but also spatiotemporal coupling effects, such as pulse front tilt, pulse front rotation, and pulse stretching. In this paper, we present a theoretical study of the spatiotemporal response of concave VLS gratings to ultra-short X-ray pulses. The theoretical analysis indicates that the tilt angle of the non-zero diffraction orders varies with the propagation distance, and disappears at the focus, where the focal lengths and pulse stretching differ for different diffraction orders. The model demonstrates the pulse duration after the concave VLS grating is the convolution of the initial pulse duration and the stretching term induced by dispersion, while the beam size at the focus in x dimension is the convolution of the geometric scaling beam size and the dispersion term. This work provides a mathematical explanation for the spatiotemporal response of concave VLS grating to ultra-short X-ray pulses and offers valuable insights into the design of FEL grating monochromators, spectrometers, pulse compressors, and pulse stretchers.
PubMed: 37859010
DOI: 10.1364/OE.501464 -
Physics in Medicine and Biology Jan 2024The goal of this work was to assess the potential use of non-contact scintillator imaging dosimetry for tracking delivery in total body irradiation (TBI).. Studies were...
The goal of this work was to assess the potential use of non-contact scintillator imaging dosimetry for tracking delivery in total body irradiation (TBI).. Studies were conducted to measure the time-gated light signals caused by radiation exposure to scintillators that were placed on tissue. The purpose was to assess efficacy in conditions common for TBI, such as the large source to surface distance (SSD) commonly used, the reduced dose rate, the inclusion of a plexiglass spoiler, angle of incidence and effects of peripheral patient support structures. Dose validation work was performed on phantoms that mimicked human tissue optical properties and body geometry. For this work, 1.5 cm diameter scintillating disks were developed and affixed to phantoms under various conditions. A time-gated camera synchronized to the linac pulses was used for imaging. Scintillation intensity was quantified in post processing and the values verified with simultaneous thermolumiescent dosimeter (TLD) measurements. Mean scintillation values in each region were compared to TLD measurements to produce dose response curves, and scatter effects from the spoiler and patient bed were quantified.The dose determined by scintillators placed in TBI conditions agreed with TLD dose determinations to within 2.7%, and did so repeatedly within 1.0% standard deviation variance. A linear fit between scintillator signal and TLD dose was achieved with an= 0.996 across several body sites. Scatter from the patient bed resulted in a maximum increase of 19% in dose.This work suggests that non-contact scintillator imaging dosimetry could be used to verify dose in real time to patients undergoing TBI at the prescribed long SSD and low dose rate. It also has shown that patient transport stretchers can significantly influence surface dose by increasing scatter.
Topics: Humans; Scintillation Counting; Whole-Body Irradiation; Radiometry; Radiotherapy Dosage; Phantoms, Imaging; Optical Imaging
PubMed: 38171002
DOI: 10.1088/1361-6560/ad1a23 -
Frontiers in Bioengineering and... 2024This paper presents the Reconfigurable Multi-Terrain Adaptive Casualty Transport Aid (RMTACTA), an innovative solution addressing the critical need for rapid and safe...
This paper presents the Reconfigurable Multi-Terrain Adaptive Casualty Transport Aid (RMTACTA), an innovative solution addressing the critical need for rapid and safe pre-hospital casualty transport in industrial environments. The RMTACTA, leveraging the Watt II six-bar linkage, offers enhanced adaptability through six modes of motion, overcoming the limitations of traditional stretchers and stretcher vehicles by facilitating navigation across narrow and challenging terrains. The RMTACTA's design incorporates two branching four-bar mechanisms to form a compact, reconfigurable Watt II six-bar linkage mechanism. This setup is controlled via a single remote rope, allowing for easy transition between its multiple operational modes, including stretcher, stretcher vehicle, folding, gangway-passing, obstacle-crossing, and upright modes. The mechanical design and kinematics of this innovative linkage are detailed, alongside an analysis of the optimal design and mechanical evaluation of rope control. A prototype of the RMTACTA was developed, embodying the proposed mechanical and kinematic solutions. Preliminary tests were conducted to verify the prototype's feasibility and operability across different terrains, demonstrating its capability to safely and efficiently transport casualties. The development of the proposed Reconfigurable Multi-Terrain Adaptive Casualty Transport Aid (RMTACTA) introduces a novel perspective on the design of emergency medical transport robots and the enhancement of casualty evacuation strategies. Its innovative application of the Watt II six-bar linkage mechanism not only showcases the RMTACTA's versatility across varied terrains but also illuminates its potential utility in critical scenarios such as earthquake relief, maritime rescue, and battlefield medical support.
PubMed: 38605994
DOI: 10.3389/fbioe.2024.1360902 -
Scientific Reports May 2024Comparison of the three methods standing-on-a-stool (SS), one knee kneeling on a stretcher (KS), and kneeling at the same height as the patient's bed on the kneeling... (Randomized Controlled Trial)
Randomized Controlled Trial
Comparison of the three methods standing-on-a-stool (SS), one knee kneeling on a stretcher (KS), and kneeling at the same height as the patient's bed on the kneeling stool (KK) to evaluate the yielded of highest CPR quality and rescuer comfortability. A prospective randomized cross-over study which compares the three different rescuer positions for their effectiveness of chest compression. Conducted at a tertiary care between 19 and 22 Aug 2022. Emergency personnel aged 18 years or older, who completed the AHA-approved BLS course. The chest compression data was obtained by the ALIVE AED manikin® and AED reporting system. The information on the CPR quality and post-test questionnaires assessing the participants' preference, satisfaction and modified Borg's scale score was collected. The three methods shown no statistically significant difference in adequate chest compression depth (percentage). KK was not superior than SS at chest compression rate (P = 0.05). The adequate full chest recoil achieved with KK and KS were significantly higher than that of SS. However, there were no statistical difference between the three methods in the modified Borg's scale score. Based on the satisfying score, the rescuers preferred KK to either SS (p 0.007) or KS (p 0.012). The three methods shown no statistically significant difference in adequate chest compression depth (percentage). Still, both KK and KS provided more adequate chest recoil, so we would recommend using these two methods in the ED.Clinical trial registry: This study was retrospective registration in thaiclinicaltrials.org (TCTR20230119002, 19/1/2023).
Topics: Humans; Cross-Over Studies; Male; Emergency Service, Hospital; Female; Adult; Cardiopulmonary Resuscitation; Prospective Studies; Stretchers; Middle Aged; Manikins
PubMed: 38811649
DOI: 10.1038/s41598-024-62845-y -
Optics Express Jun 2023Optical quantum information processing requires low loss interference of quantum light. Also, when the interferometer is composed of optical fibers, degradation of...
Optical quantum information processing requires low loss interference of quantum light. Also, when the interferometer is composed of optical fibers, degradation of interference visibility due to the finite polarization extinction ratio becomes a problem. Here we propose a low loss method to optimize interference visibility by controlling the polarizations to a crosspoint of two circular trajectories on the Poincaré sphere. Our method maximizes visibility with low optical loss by using fiber stretchers as polarization controllers on both paths of the interferometer. We also experimentally demonstrate our method, where the visibility was maintained basically above 99.9% for three hours using fiber stretchers with an optical loss of 0.02 dB (0.5%). Our method makes fiber systems promising for practical fault-tolerant optical quantum computers.
PubMed: 37381343
DOI: 10.1364/OE.489082