VR-based training of craniotomy for intracranial aneurysm surgery

Purpose Intracranial aneurysms can be treated micro-surgically. This procedure involves an appropriate head position of the patient and a proper craniotomy. These steps enable a proper access, facilitating the subsequent steps. To train the access planning process, we propose a VR-based training system. Method We designed and implemented an immersive VR access simulation, where the user is surrounded by a virtual operating room, including medical equipment and virtual staff. The patient’s head can be positioned via hand rotation and an arbitrary craniotomy contour can be drawn. The chosen access can be evaluated by exposing the aneurysm using a microscopic view. Results The evaluation of the simulation took place in three stages: testing the simulation using the think-aloud method, conducting a survey and examining the precision of drawing the contour. Although there are differences between the virtual interactions and their counterparts in reality, the participants liked the immersion and felt present in the operating room. The calculated surface dice similarity coefficient, Hausdorff distance and feedback of the participants show that the difficulty of drawing the craniotomy is appropriate. Conclusion The presented training simulation for head positioning and access planning benefits from the immersive environment. Thus, it is an appropriate training for novice neurosurgeons and medical students with the goal to improve anatomical understanding and to become aware of the importance of the right craniotomy hole.

Evaluation and Feasibility of a Head Positioning Intervention in Patients with Intraparenchymal Hemorrhage

Stroke caused by intraparenchymal hemorrhage (IPH) is most commonly the result of hypertension-induced blood vessel rupture in the brain and is associated with devastating disability and high rates of death. To date, no intervention has improved outcomes in IPH stroke patients; however, head elevation may be one of the most important first steps to promote clinical stability in the hyperacute stage of IPH stroke because of the risk of increased intracranial pressure (ICP) in these patients. Nursing research completed in the late 1970s and early 1980s in patients with increased ICP due to traumatic brain injury showed that elevating the head of bed (HOB) increased gravity drainage of venous blood and cerebrospinal fluid, lowering ICP, However, no study has yet been completed in a generalizable sample of hyperacute IPH stroke patients to examine serial changes in clinical stability in relation to HOB positioning. Recently, the Head Position in Stroke Trial (HeadPoST), which enrolled a highly heterogeneous sample of subacute stroke patients, found that head position does not affect 3-month outcome; however, the study was heavily criticized by international stroke experts due to significant internal validity concerns. HeadPoST findings have created significant confusion within the acute stroke practice community about whether there is a role for head positioning in hyperacute IPH stroke management. The focus of our research was to build knowledge of key clinical methods that will support future definitive HOB research in hyperacute IPH stroke patients. We established 1) the clinical knowledge and skill set supporting nurses’ ability to localize stroke disability within vascular territories in the brain and 2) use of the National Institutes of Health Stroke Scale as a valid assessment tool for serial monitoring of clinical change in hyperacute IPH patients. We also 3) examined the degree of acceptance of HeadPoST findings internationally among nurse and physician clinicians caring for IPH stroke patients and 4) evaluated elements tied to the feasibility of conducting hyperacute IPH HOB research at a large, comprehensive stroke center in the Midsouth. Collectively, the chapters in this dissertation create a foundation for future IPH head-positioning research, providing direction for our next steps in understanding the contribution of HOB positioning to hyperacute IPH patient management. Patients with hypertensive IPH stroke suffer significantly higher rates of disability and death compared to other forms of stroke, yet despite a great deal of inquiry into interventions to improve outcomes, none have been successful. Positioning the patient’s HOB at 30-degrees may be one of the most important early interventions that nurses can employ to impart stability in hypertensive IPH patients. Our research and conclusions position nurse scientists to further their examination of the effect of this simple HOB-positioning intervention in this highly vulnerable patient population.

Post-translational modification patterns on β-myosin heavy chain are altered in ischemic and non-ischemic human hearts

Phosphorylation and acetylation of sarcomeric proteins are important for fine-tuning myocardial contractility. Here, we used bottom-up proteomics and label-free quantification to identify novel post-translational modifications (PTMs) on beta-myosin heavy chain (β-MHC) in normal and failing human heart tissues. We report six acetylated lysines and two phosphorylated residues: K34-Ac, K58-Ac, S210-P, K213-Ac, T215-P, K429-Ac, K951-Ac, and K1195-Ac. K951-Ac was significantly reduced in both ischemic and non-ischemic failing hearts compared to non-diseased hearts. Molecular dynamics simulations show that K951-Ac may impact stability of thick filament tail interactions and ultimately myosin head positioning. K58-Ac altered the solvent exposed SH3 domain surface – known for protein-protein interactions – but did not appreciably change motor domain conformation or dynamics under conditions studied. Together, K213-Ac/T215-P altered loop 1’s structure and dynamics – known to regulate ADP-release, ATPase activity, and sliding velocity. Our study suggests that β-MHC acetylation levels may be influenced more by the PTM location than the type of heart disease since less protected acetylation sites are reduced in both heart failure groups. Additionally, these PTMs have potential to modulate interactions between β-MHC and other regulatory sarcomeric proteins, ADP-release rate of myosin, flexibility of the S2 region, and cardiac myofilament contractility in normal and heart failure hearts.

Comparison between Sniffing Position and 25 Degree Backup Position in View of Glottis During Direct Laryngoscopy and Intubation - A Study from Mangalore, Karnataka

BACKGROUND Endotracheal intubation for the purpose of providing anaesthesia was first described by William Mc Ewan. Jackson1 stressed the importance of anterior flexion of the lower cervical spine, in addition to obvious extension of the atlanto-occipital joint. Sniffing position has been commonly advocated as a standard head positioning for direct laryngoscopy which is achieved by flexion of the neck on chest and extension of the head at the atlanto-occipital joint. Present study was designed to evaluate the glottis view and ease of intubation achieved with direct laryngoscopy in the sniffing position with that of 25 degree backup position in a study group of 100 patients divided in 2 groups of 50 each. METHODS This study is a controlled comparative study. Controlled trial in 50 consecutive patients in each group [Group I and Group II] was conducted on patients who underwent elective surgery under general anaesthesia. Inclusion Criteria - General anaesthesia with endotracheal intubation, Aged 18 to 60 years, American society of Anaesthesiologists (ASA) grades I and II. Exclusion Criteria - Patients with body mass index more than 30 kg/m2. 1. Bucked teeth. 2. Restricted neck movement. 3. Inter-incisor gap less than 35 mm. 4. Thyro-mental distance less than 6 mm. 5. Patients with risk of regurgitation and aspiration. 6. Pharyngeal pathology. 7. Limitation of anterior and posterior movement of mandible 8. Pregnant patients Groups wereGroup I – Sniffing position Group II– 25 degree back up position RESULTS The glottis visualization was assessed by Cormack Lehane grading which revealed that glottis view was better in 25 degree backup position than sniffing position. CONCLUSIONS In our prospective randomized study in a series of 50 patients undergoing general anaesthesia in SIMS & RC, intubation difficulty scale (IDS) score was better in 25 degree backup position than sniffing position. It implies glottis view is better in 25 degree backup position than sniffing position. KEYWORDS Sniffing Position, 25 Degree Backup Position, Laryngoscopy

Vector Analysis of High Astigmatism (≥2.0 Diopters) Correction after Small-Incision Lenticule Extraction with Stringent Head Positioning and Femtosecond Laser-Assisted Laser in Situ Keratomileusis with Compensation of Cyclotorsion

PURPOSE： To compare the astigmatic correction by vector analysis in the high myopic astigmatism between femtosecond laser-assisted laser in situ keratomileusis with compensation of cyclotorsion (FS-LASIK) and small-incision lenticule extraction(SMILE) with stringent head positioning.SETTING: Beijing Aier-Intech Eye Hospital, Beijing, China.DESIGN: Retrospective case series. METHOD: Patients who had correction of myopic astigmatism of 2 diopters (D) or more had either FS-LASIK with compensation of cyclotorsion or SMILE with stringently control the head position were included. Results of vision and refraction were analyzed and compared between groups with the right eye.RESULT: The study enrolled 94 patients (41eye in the FS-LASIK with compensation of cyclotorsion and 53 eyes in SMILE with stringently control the head position). The mean preoperative manifest cylinder was -2.65±0.77D in FS-LASIK and 2.51±0.56D in SMILE group. (P=0.302). At 12-month, there was no significant difference between the two groups in uncorrected distance visual acuity (UDVA, P = 0.274) and postoperative spherical equivalent (P=0.107). 46.3% and 24.5% of eyes were within 0.25D post-op cylinder, 78% and 66% of eyes were within 0.5 D post-op cylinder for FS-LASIK group and SMILE group, respectively (P=0.027, P = 0.202). Vector analysis showed comparable target-induced astigmatism (TIA, P=0.114), surgically induced astigmatism vector (SIA, P=0.057), difference vector (DV, P=0.069) and the angle of error (AE, P=0 .213) between groups. Index of success (IOS) was 0.18 in the FS-LASIK and 0.24 in the SMILE (P=0.024), and significant difference for two groups.CONCLUSION: FS-LASIK with compensation of cyclotorsion had favorable correction in high myopic astigmatism (≥2.0 diopters) compared to SMILE with stringent head positioning at 12-month.

Effectiveness of sustained natural apophyseal glides in females with cervicogenic headache: A randomized controlled trial

BACKGROUND: Cervicogenic headache (CGH) is a common condition that results in significant disability. To treat this dysfunction, Mulligan described sustained natural apophyseal gliders (SNAGs) as a manual therapy approach. However, only inconclusive short-term evidence exists for treating CGH with SNAGs. OBJECTIVE: The present study aims to investigate the effect of SNAGs in the treatment of CGH. METHODS: Fourty female patients ranging from 20 to 40 years with CGH were randomly assigned to two groups: 20 in a treatment group and 20 in a control group. SNAGs were applied to the treatment group while the control group received placebo treatment. Both groups received their respective treatment for 20 minutes, alternately three times per week, for a total of 12 times in four weeks. The outcome measures were the Neck Disability Index (NDI) and the Visual Analogue Scale (VAS). Participants were assessed at baseline and at the end of each week. The data was analyzed using SPSS version 20. Independent t-testing was used to reveal changes between groups. One-way ANOVA was used to determine changes within groups. The level of significance was P< 0.05. RESULTS: Twenty participants (100%) in the treatment group and 17 (85%) in the control group had a history of headache aggravation with active movements or passive head positioning. There was no significant difference at baseline (p> 0.05), indicating that both groups were homogeneous at the time of recruitment. The p value (p< 0.05) showed a significant difference in pain and level of disability at three and four weeks (p< 0.05) in patients treated with SNAGs. However, the cervical range of motion (ROM) showed a statistically significant improvement in flexion and extension in the treatment group (p< 0.05) while there was no significant improvement in side flexion and rotation ROM in both groups (p> 0.05). CONCLUSION: This study found that SNAGs were effective in reducing pain and neck disability and improved ROM in females with CGH.

THE IMPACT OF HEAD POSITIONING ON THE IMAGE QUALITY OF MULTI-DETECTOR COMPUTED TOMOGRAPHY

Radiologic technologists face various types of patients during multi-detector computed tomography (CT) examinations. In emergency departments, it is common to have patients who cannot follow instructions for the examinations. The asymmetric axial view of the head CT might affect the correctness of the clinician’s diagnosis. This study aimed to assess the impact of head positioning on the image quality of head CT using two phantoms. All scans were performed on a 16-slice CT scanner. In the control group, the tilted angle of the phantoms was 0[Formula: see text], and no multiplanar reconstruction (MPR) was performed. In the experimental groups, the tilted angles of the phantoms were 5[Formula: see text], 10[Formula: see text] and 15[Formula: see text], respectively, and MPR was performed afterwards. The results showed that if the head was tilted during the head CT examinations, image asymmetry and artifacts appeared without MPR. After MPR, one phantom showed that there were significant differences and the other phantom showed no significant differences quantitatively in image symmetry and artifacts between experimental groups and the control group, while both phantoms showed no significant differences qualitatively in image symmetry and artifacts between experimental groups and the control group. Although MPR can correct the image asymmetry and artifacts caused by tilted head positioning to some extent, it consumes time. Therefore, technologists should position the head as exactly as possible when performing head CT examinations.

The “right” side of sleeping: laterality in resting behaviour of Aldabra giant tortoises (Aldabrachelys gigantea)

Although some studies investigated lateralization in reptiles, little research has been done on chelonians, focusing only on few behaviours such as righting response and escape preference. The aim of this study was to investigate lateralization in Aldabra giant tortoises (Aldabrachelys gigantea), focusing on asymmetrical positioning of the limbs and the head during resting behaviour, called sleep-like behaviour, involving both wild tortoises and individuals under human care. Subjects of the study were 67 adult Aldabra tortoises (54 free ranging on Curieuse, 13 under human care in Mahè Botanical Garden). For each tortoise observed during sleep-like behaviour, we recorded the position of the head (on the left, on the right or in line with the body midline) and we collected which forelimb and hindlimb were kept forward. Moreover, the number of subjects in which limbs were in a symmetrical position during the sleep-like behaviour was recorded. Based on our results, the number of tortoises with asymmetrical position of head and limb was higher (head: 63%; forelimbs: 88%; hindlimbs: 70%) than the number of tortoises with symmetrical position of the head and the limb. Regarding the head, throughout the subjects found with the asymmetrical position of the head during sleep-like behaviour, tortoises positioning the head on the right (42%) were more than those sleeping with the head on the left (21%). We found a relationship between the position of the forelimbs and hindlimbs during sleep-like behaviour. We reported no differences between Mahè (under human care) and Curieuse (wild) tortoises. Findings of this preliminary study underlined traces of group-level lateralization in head positioning during the sleep-like behaviour, possibly due to a left-eye/right-hemisphere involvement in anti-predatory responses and threatening stimuli as reported in reptiles and other vertebrates. This study aims at adding data on brain lateralization, often linked to lateralized behaviours, in reptiles, especially in chelonians.

Influence of the Bed Head Positioning on the Current Expiratory Volume of Pediatric Patients in Mechanical Ventilation: A Pilot Clinical Controlled Trial

he elevated bed head position is an important therapeutic intervention that can reduce respiratory complications associated with mechanical ventilation. The objective of this study was to evaluate the effects of elevation at the head of the bed on the tidal volume, pressure variables, hemodynamic data and peripheral oxygen saturation in pediatric patients on mechanical ventilation. Methods: In a before-and-after clinical trial, 52 patients of both sexes, with a chronological age of 28 days to 14 years old, were admitted to the pediatric intensive care unit for more than 24 hours. These were positioned at 0º, 30º, 45º and 60º of elevation of the head of the bed. For each position, the expiratory tidal volume, pressure variables, hemodynamic data and peripheral oxygen saturation were evaluated. Results: The patients presented an increase in the expired tidal volume, with the bed head angulation at 30º and 45º. Heart rate increased when the head was positioned at 60º. The peripheral oxygen saturation variable increased in the 30º and 45º positions. The systolic blood pressure variables and diastolic blood pressure showed a progressive increase in the 30º, 45º and 60º positions respectively. Significant effects on increasing the SatO2/FiO2 ratio were observed in the 30º and 45º positions. Conclusion: This study demonstrated a significant increase in expired tidal volume and an increase in the SatO2/FiO2 ratio with the patient positioned at 30º and 45º of elevation of the head of the bed. The peripheral oxygen saturation variable increased in the 30º and 45º positions. The elevated bed head position should be considered when monitoring children during mechanical ventilation.

HEAD-POSITIONING CONTROL IN TRIPLE-STAGE-ACTUATOR ENTERPRISE HARD DISK DRIVES USING MIXED H2/H∞ SYNTHESIS METHODOLOGIES

The recent rapid growth in the cloud storage industry has strongly increased the demand for high-capacity hard disk drives (HDDs). Increasing the areal density brings new challenges to the high-accuracy head-positioning control in the next generation HDD development. Triple-stage-actuator (TSA) system is one of the emerging technologies that can achieve higher bandwidth than that of a dual-stage-actuator (DSA) system and improve the track-following performance. In this paper, we focus on the track-following controller design for TSA system with one voice coil motor (VCM) and two piezoelectric (PZT) actuators. Two types of mixed H2/Hinf synthesis methodologies based on model-based optimization and data-driven optimization are proposed to design the track-following controller for the TSA system. The TSA system can increase the bandwidth of the servo system and decrease the sensitivity to disturbances at the low-frequency range. While increasing the stroke limitation and the resonance frequency of the micro-actuator, the 3sigma the position error signals (PES) is reduced. The data-driven controller can achieve comparable head-positioning accuracy to the model-based controller when it converges to a local optimal solution. The simulation results show the feasibility and effectiveness of the TSA systems with a tertiary PZT actuator. We also analyze the effects of stroke limitations and resonance frequencies of the second/third-stage PZT actuators on the head-positioning accuracy. The results might provide a guideline for the TSA mechanical design.