Pneumatic Device Research Articles

Abdominal Palpation Haptic Device for Colonoscopy Simulation Using Pneumatic Control.

In this paper, we describe the development of a haptic device to be used in a simulator aiming to train the skills of gastroenterology assistants in abdominal palpation during colonoscopy, as well as to train team interaction skills for the colonoscopy team. To understand the haptic feedback forces to be simulated by the haptic device, we conducted an experiment with five participants of varying BMI. The applied forces and displacements were measured and hysteresis modeling was used to characterize the experimental data. These models were used to determine the haptic feedback forces required to simulate a BMI case in response to the real-time user interactions. The pneumatic haptic device consisted of a sphygmomanometer bladder as the haptic interface and a fuzzy controller to regulate the bladder pressure. The haptic device showed good steady state and dynamic response was adequate for simulating haptic interactions. Tracking accuracy averaged 94.2 percent within 300 ms of the reference input while the user was actively applying abdominal palpation and minor repositioning.

Increased apoptotic neuronal cell death and cognitive impairment at early phase after traumatic brain injury in aged rats

Progressive age-associated increases in cerebral dysfunction have been shown to occur following traumatic brain injury (TBI). Moreover, levels of neuronal mitochondrial antioxidant enzymes in the aged brain are reduced, resulting in free radical-induced cell death. It was hypothesized that cognitive impairment after TBI in the aged progresses to a greater degree than in younger individuals, and that damage involves neuronal degeneration and death by free radicals. In this study, we investigated the effects of free radicals on neuronal degeneration, cell death, and cognitive impairment in 10-week-old (young group) and 24-month-old rats (aged group) subjected to TBI. Young and aged rats received TBI with a pneumatic controlled injury device. At 1, 3 and 7days after TBI, immunohistochemistry, lipid peroxidation and behavioral studies were performed. At 1, 3 and 7days post-TBI, the number of 8-hydroxy-2'-deoxyguanosine-, 4-hydroxy-2-nonenal- and single-stranded DNA (ssDNA)-positive cells, and the levels of malondialdehyde around the damaged area after TBI significantly increased in the aged group when compared with the young group (P<0.05). In addition, the majority of ssDNA-positive cells in both groups co-localized with neuronal cells around the damaged area. There was a significant decrease in the number of surviving neurons and an increase in cognitive impairment after TBI in the aged group when compared with the young group (P<0.05). These results indicate that following TBI, high levels of free radicals are produced in the aged rat brain, which induces neuronal degeneration and apoptotic cell death around the damaged area, resulting in cognitive impairment.

Development of High Contractile Pneumatic Artificial Rubber Muscle for Power Assist Device

The purpose of this study is to develop a pneumatic artificial rubber muscle that has a high contraction rate in order to realize the required performance for a power assist device. In addition, a bilateral type pneumatic wearable master-slave training device is developed as an application of this muscle. The developed rubber muscle is constructed with two nylon bands and an expansion unit, which is put between the nylon bands. The generated force from the expansion unit is converted to a contraction force by the nylon band. This rubber muscle can realize the high contraction rate. The high contractile rubber is used in the form of actuators in the developed knee device because of the above feature. In this paper, the structure and characteristics of the developed rubber muscle are described and then the structure of the developed master-slave device is described. Finally, the validity of the proposed device is evaluated from an experiment that assumes rehabilitation.

Development of a Pneumatic Tensioning Device for Gap Measurement during Total Knee Arthroplasty

BackgroundDespite the importance of soft tissue balancing during total knee arthroplasty (TKA), all estimating techniques are dependent on a surgeon's manual distraction force or subjective feeling based on experience. We developed a new device for dynamic gap balancing, which can offer constant load to the gap between the femur and tibia, using pneumatic pressure during range of motion.MethodsTo determine the amount of distraction force for the new device, 3 experienced surgeons' manual distraction force was measured using a conventional spreader. A new device called the consistent load pneumatic tensor was developed on the basis of the biomechanical tests. Reliability testing for the new device was performed using 5 cadaveric knees by the same surgeons. Intraclass correlation coefficients (ICCs) were calculated.ResultsThe distraction force applied to the new pneumatic tensioning device was determined to be 150 N. The interobserver reliability was very good for the newly tested spreader device with ICCs between 0.828 and 0.881.ConclusionsThe new pneumatic tensioning device can enable us to properly evaluate the soft tissue balance throughout the range of motion during TKA with acceptable reproducibility.

КРИМИНАЛИСТИЧЕСКОЕ ИССЛЕДОВАНИЕ МАРКЕРОВ ДЛЯ ИГРЫ В ПЕЙНТБОЛ

The article discusses the study of pneumatic shooting device - markers to paintball games based on existing national normative and technical documents. An example of research markers for paintball games in order to assign them to a certain category of objects for customs control purposes.

S052026 ボルテックスカップ内の旋回流特性

In semiconductor manufacturing, a new pneumatic non-contact handling device is developed. This device named Vortex Cup makes use of a negative pressure at a central area of swirling flow in order to hold the wafer and to prevent significant wafer damage and foreign material contamination. The Cup provides lower-cost, higher-performance than other pneumatic type devices, but has a problem that periodic pressure fluctuation is caused when the gap height between the work and the Cup becomes large. This problem causes the work falling or the work collision against the cup. In this report, we proposed simple method for suppression of the pressure fluctuation by using cylinders set into the cup. As a result, it was revealed that the cylinder diameter has great effect on the fluctuation suppression, but the height has little influence on it. PIV measurement clarified that the meandering motion of swirling flow in a cup was disappeared when the pressure fluctuation was suppressed.

A two-dimensional, heart-cutting preparative gas chromatograph facilitates highly resolved single-compound isolations with utility towards compound-specific natural abundance radiocarbon (14C) analyses

Motivated by the need to develop clean, high purity preparative enrichments of individual compounds for micro-scale compound-specific natural abundance isotope and radiocarbon ((14)C) analyses, we describe a new, two-dimensional, heart-cutting, low-bleed, three-oven, single GC preparative system, demonstrate its resolving capabilities as applied to a typically complex environmental sample matrix, and investigate the robustness with which it preserves the authigenic (13)C/(12)C and (14)C/(12)C ratios of individual compounds it targets for preparative enrichment. The system is comprised of a programmable temperature vaporizing (PTV) inlet, a single GC oven, two modular, door-mounted, resistively heated low thermal mass (LTM) columns, a preparative fraction collector (PFC), and a Deans pneumatic switching device which facilitates heart-cutting between the system's 1° and 2° chromatographic dimensions. Further, the system's inlet and trapping parameters are optimized for the efficient preparative enrichment of the methyl ether and ester derivatives of the lignin phenol compound class. The lignin phenols include such compounds as the vanillyl and syringyl aldehydes, ethanones, and acids and are unrivaled biomarkers of terrestrial organic matter, some of which are also important components of fragrances and flavors. Using this suite of compounds, the suitability of this augmented preparative capillary GC (PCGC) system was investigated for micro-scale compound-specific (CS) stable isotope and natural abundance radiocarbon analyses (RA). Analysis of a >300 injection enrichment scheme reveals the instrument to fractionate (13)C in predictable ways and to preserve the authigenic Δ(14)C of compounds it targets for preparative enrichment to within 6.7±5.0‰, demonstrating the promising new utility of such systems towards micro-scale CSRA investigations for which clean and high resolution separation techniques are prerequisite.

Abstract 60: Dexmedetomidine Administration During CPR Improves Stroke Volume During the Early Postresuscitation Period

Introduction: Elevated sympathetic response after CPR worsens myocardial dysfunction and cardiac output. Dexmedetomodine has sympatholytic effects both in animal and human studies. Hypothesis: Dexmedetomidine given during CPR improves stroke volume (SV) after ROSC compared with standard CPR. Methods Sixteen anesthetized &amp; ventilated (2 months old) farm pigs (UF Research Swine) of either sex were blindly randomized (8/group) after induction of ventricular fibrillation (VF; via direct right ventricular current) to receive either dexmedetomidine (2 mcg/kg) or placebo after the first minute of chest compressions per AHA CPR guidelines. Chest compressions were delivered at 100/min by a pneumatic compressor device (Thumper, Michigan instruments, USA) and 21% FiO 2 was used for ventilation. SV was measured at 15, 30, 60, 90 and 120 minutes after ROSC using a Pressure-Volume (P-V) catheter in the left ventricle (Millar instruments, Michigan, USA). Cardiac output was calculated from SV and heart rate. Outcome (mean±SD) was analyzed using mixed linear model (SAS Proc MIXED). We used an unpaired t-test for the differences between groups at each time point; p-value ≤0.05 was considered significant. Results Dexmedetomidine group had significantly higher stroke volume (% change from baseline) at 15 minutes (97±24 vs. 44±19, p =0.0006) and 30 minutes (87±26 vs. 51±21 p =0.0153). CO (% change from baseline) was higher in Dex group at 15 minutes (141±53 vs. 61±23, p =0.0061) and at 30 minutes (115±44 vs. 55±17 p =0.0122). SV and CO were higher, but not significantly after 30 minutes. The study group had significantly higher CO (% change from baseline) across all time points combined compared with the control group (89.3±6.14 vs. 60.1±7.15, p=0.0033). End-diastolic volume trended higher in Dexmedetomidine group but was not significant. HR was not different between the two groups. Conclusions Dexmedetomidine, when given during the initial cycle of chest compressions during CPR, increases SV and CO early post ROSC. Further studies are needed to evaluate the appropriate dose, continuous infusion and time of administration.

Abstract 198: Dexmedetomidine During CPR Blunts the Increase in Oxygen Consumption in Early ROSC

Introduction: Cardiac arrest significantly increases endogenous catecholamines, which stimulates increased oxygen consumption after ROSC. In animals, adrenergic blockade during and immediately after CPR improves post arrest cardiac function. Dexmedetomodine has sympatholytic effects both in animal and human studies. Hypothesis: Dexmedetomidine given during CPR reduces oxygen consumption after ROSC as compared with standard CPR. Methods Sixteen anesthetized &amp; ventilated (2 months old) farm pigs (UF Research Swine) of either sex were blindly randomized (8/group) after induction of ventricular fibrillation (via direct right ventricular current) to receive either dexmedetomidine (2 mcg/kg) or saline placebo after the first minute of chest compressions during CPR per AHA guidelines. Chest compressions were delivered at 100/min by a pneumatic compressor device (Thumper, Michigan instruments, USA) and 21% FiO 2 was used for ventilation. Oxygen consumption was measured from exhaled gas analysis at 15, 30, 60, 90 and 120 minutes after ROSC using a metabolic measurement system (TrueOne® 2400, Parvomedics, USA). Data (mean±SD) was analyzed using a mixed linear model (SAS Proc MIXED). We used an unpaired t-test for the differences between groups at each time point; p-value ≤0.05 was considered significant. Results Oxygen consumption (% change from baseline) was significantly lower in the dexmedetomidine group, 121%±4.16, vs. Saline, 143%±5.32, p=0.0093. Dexmedetomidine group had significantly lower oxygen consumption at 15 minutes (111%±22 vs. 150%±29, p =0.0365) and at 30 minutes (114%±24 vs.151%±19, p =0.0122. The oxygen consumption was not significantly different at 60, 90 and 120 minutes. There was no difference between groups with reference to time to ROSC and doses of epinephrine given. Conclusions. Dexmedetomidine, when given during the initial cycle of chest compressions during CPR, attenuates the elevated oxygen consumption during the post ROSC period. Further studies are needed to evaluate the effects of higher doses or continuous infusion and the optimal time of administration.

Characterization of novel pneumatic mixing for single-use bioreactor application

Background The novel bioreactor system from PBS Biotech is the first with a pneumatic mixing device powered solely by gas buoyancy, eliminating the need for an external mechanical agitator. The patented design of the AirWheel mixing device promotes not only high tangential fluid flow around the wheel but also efficient radial and axial flows. The leverage effect of the Air-Wheel mixing device also allows for lower gassing requirement (v/v) with increasing working volume, making the power utilization from the gas buoyancy more efficient with scale. A series of physical tests were performed to demonstrate that PBS systems can promote uniform, homogenous mixing over a wide range of working volumes and can offer a low-shear environment for cell culture. A series of biological tests were then performed at various evaluation sites to confirm the physical test results.

Study of a Precision Pneumatic Positioning Device Using PZT Dither

A piezoelectric (PZT) actuator featuring a high frequency response is employed to serve as a highfrequency dither and to compensate for the nonlinear motion characteristic of a pneumatic positioning device. To examine the function of the PZT dither, system identification based on a linear model for describing the positioning device was performed. To obtain the most suitable actuating parameters of the PZT dither, the Taguchi method was employed. Using the optimal parameters, the positioning system implemented by the PID controller was configured. For a target position of 4 mm, position control with a positioning accuracy under 0.1 µm was demonstrated. Compared to the pneumatic positioning device using a traditional controller, the device presented in this study features better positioning ability.

Continuous Control of Tracheal Cuff Pressure and Microaspiration of Gastric Contents in Critically Ill Patients

Underinflation of the tracheal cuff frequently occurs in critically ill patients and represents a risk factor for microaspiration of contaminated oropharyngeal secretions and gastric contents that plays a major role in the pathogenesis of ventilator-associated pneumonia (VAP). To determine the impact of continuous control of tracheal cuff pressure (P(cuff)) on microaspiration of gastric contents. Prospective randomized controlled trial performed in a single medical intensive care unit. A total of 122 patients expected to receive mechanical ventilation for at least 48 hours through a tracheal tube were randomized to receive continuous control of P(cuff) using a pneumatic device (intervention group, n = 61) or routine care of P(cuff) (control group, n = 61). The primary outcome was microaspiration of gastric contents as defined by the presence of pepsin at a significant level in tracheal secretions collected during the 48 hours after randomization. Secondary outcomes included incidence of VAP, tracheobronchial bacterial concentration, and tracheal ischemic lesions. The pneumatic device was efficient in controlling P(cuff). Pepsin was measured in 1,205 tracheal aspirates. Percentage of patients with abundant microaspiration (18 vs. 46%; P = 0.002; OR [95% confidence interval], 0.25 [0.11-0.59]), bacterial concentration in tracheal aspirates (mean ± SD 1.6 ± 2.4 vs. 3.1 ± 3.7 log(10) cfu/ml, P = 0.014), and VAP rate (9.8 vs. 26.2%; P = 0.032; 0.30 [0.11-0.84]) were significantly lower in the intervention group compared with the control group. However, no significant difference was found in tracheal ischemia score between the two groups. Continuous control of P(cuff) is associated with significantly decreased microaspiration of gastric contents in critically ill patients.

Study on Noise Control of Fan with Air Suction

Fan is a pneumatic device in the 4ZTL-1800 combine harvester threshing prior to cutting. Based on the prophase search result that fan noise is highest when fan rotates at 1200r/min, in order to decrease noise of it, sigle-microperferated-panel muffler, double-microperferated-panel muffler and interposition muffler were designed and tested. The results show that double-microperferated-panel muffler is best and sound power level of fan is decreased 11dB, and that interposition muffler is better, and that sigle-microperferated-panel muffler is worst to descrease fan noise. Through contrast on transmission power loss of different mufflers, cone-shaped double-microperferated-panel muffler is verified to be best for noise control of fan.

Experimental and numerical study of vortex gripper with a diversion body

This article introduces a new vortex gripper with a diversion body. Vortex gripper, as a pneumatic non-contact handling device, can generate lifting force to hold a workpiece without any contact. In order to predict the characteristics of this new vortex gripper, including pressure distribution on the upper surface of the workpiece, lifting force, supporting stiffness, and flowrate, a computational fluid dynamics study has been carried out. In the vortex cup, air swirling flow is a complex turbulent one; so Reynolds stress model (RSM) was used to describe internal air swirling flow. In addition, an experiment was carried out to study the characteristics of the vortex gripper. When compared with the experimental results, the reliability of numerical simulation results by RSM was verified. The vortex gripper with a diversion body could generate greater lifting force when compared with those designed by Xin et al. with the same air consumption. Therefore, the efficiency of the vortex gripper is improved.

The Pneumatic Feeding System of Electrospinning Based on Numerical Simulation and System Identification

Electrospinning, which is a technology to make nano fiber, has quite high requirements of the speed of feeding. In order to solve the unstable phenomenon, salivation, and achieve the stability of quality, numerical simulation is used to compute the nozzle exit pressure and exit velocity, while recursive least squares is used to identify of the results of the simulation. At last, PID algorithm and recursive least squares methods are combined together to form a model for the feeding system controller. And the pneumatic device and pressure sensor are used to build electrospinning feeding system. Finally, experimental verification PEO solution is used to verify this method, no drooling electrospinning phenomenon happens

Bond graph modeling of planar prismatic joints

Neglecting dynamic load during design of a prismatic joint for high-speed operation may lead to unpredictable failures. A slider joint is usually a part of a pneumatic or hydraulic actuation device which may further involve complicated control systems. Thus, design/analysis of prismatic joints calls for a multi-energy domain modeling approach such as bond graph for reusability of the model in different application scenarios. The slider is treated to be a multibody system composed of two separate rigid bodies which are constrained to produce the desired motion. The constraints generate the dynamic contact forces which are used to compute the dynamic frictional forces. The bond graph model of the planar slider component developed in this article accurately calculates the dynamic loads. The model is first validated through numerical simulations performed on a Rapson slide. Thereafter, a multi-energy model for a V-twin engine and its mounting is developed to show how bond graph modeling makes it possible to create an integrated model of thermal, pneumatic and mechanical systems. Finally, the bond graph model of a three-dimensional prismatic joint is developed.

The Influence of Medial Substructures on Rupture in Bovine Aortas

The substructures of an aorta wall in hypertension play a critical mechanical role in aorta damage and possible rupture. The goal is to develop a hypothesis for these invisible dynamic mechanisms in a rupturing wall from the rupture surface morphology. Rupture mechanisms suggested by tensile tests, including histological images of the crack, are explored on a novel pneumatic device to expand ring specimens excised from bovine aorta. This technique elucidates the role in rupture of the medial substructures, the wall thickness and the moisture content of the specimen using images of the rupture surface, weight measures, and measurements of the permanent deformation prior to rupture and also at rupture. In both excised aorta tensile strip specimens and ring specimens, collagen fiber pull-out due to shear is a prerequisite for rupture, and is reflected in local permanent deformation that precedes rupture. Some of this permanent deformation is recovered by rehydrating the specimen. In the specimens loaded parallel to the collagen fibers, the change in crack direction shown in histological images of uniaxial specimens is reflected in rings by the acute rupture angle with the load direction. A hypothesis is proposed for the rupture mechanisms in the aorta wall that involves shear of the connections between fascicle substructures in the media. The results suggest requirements for a mathematical model of the aorta wall in hypertension that is more realistic than the usual hyperelastic models.

Brain activity during stepping: A novel MRI-compatible device

Little is known about the impact of supraspinal centers on the control of human locomotion. Analyzing brain activity can help to clarify their impact and to improve the effects of locomotor training. A fMRI-compatible pneumatic robotic device is presented that can generate freely programmable, highly repetitive periodic active and passive leg movements comprised by hip, knee, and ankle joint displacements. Forces of up to 400N can be applied to each foot while the subject is lying in a supine position. Magnetic interference of the device with the magnetic field of the scanner is measurable, but does not affect the image quality as obtained by a usual image analysis procedure. In a first experiment, brain activity of one healthy subject was acquired during nine different gait-like movement conditions. Brain activity in the somatosensory and motor function related areas increased more when the subject actively moved the legs than when the legs were passively moved by the device. In almost all conditions, mean head motion could be limited to 2mm within the duration of one fMRI scan by a specifically developed head and trunk fixation system. Based on these results, it is concluded that our device will significantly contribute to a better understanding of human locomotor control and related therapeutic effects in spinal cord injured and stroke patients, and thereby, to improve training approaches.

Lidocaine Jell Instillation During Ureteroscopic Stone Fragmentation Effectively Reduces Stone Migration

Introduction: Inadvertent migration of stone during ureteroscopy is a relatively common problem. In this video we are describing a cost-effective technique for prevention of inadvertent stone pushback during ureteroscopy. The current study and our previous work1 studied the efficacy of Lidocaine jelly instillation proximal to the ureteral stone during intracorporeal lithotripsy using a semi rigid ureteroscope for the prevention of retrograde migration and improvement in stone-free rate. The video is on MPEG format and the run time is 10 min. Materials and Methods: The technique described involved Lidocaine jelly instillation proximal to the stone before fragmentation. The jell is instilled either by using an open end ureteral catheter bypassing the stone under Ureteroscopic guidance or by bypassing the stone with the ureteroscope and instilling jell via the working channel of the ureteroscope. The ureteroscopy was performed using an 8F, 7F, or 6.4F semi rigid ureteroscope. A 5F ureteral stent was advanced beyond the stone. Lidocaine jelly (2 mL) was instilled and lithotripsy was performed with a Swiss LithoClast™. Alternatively, fragmentation can also be performed using a holmium laser. After the procedure, either a 5F ureteral catheter was left in place for 24 h or an indwelling Double-J stent is left in place for 2–4 weeks. Patients were followed at 24 h with plain X-ray of the kidneys, ureters, and bladder, and at 2 weeks with noncontrast enhanced computerized tomography of the kidneys, ureters, and bladder. Results: Instillation of jell before laser or pneumatic fragmentation of ureteral stone is associated with significant reduction in inadvertent stone migration during ureteroscopy. Use of jell is not associated with any side effects. However, during fragmentation using pneumatic lithotripsy devise and laser, there is some masking of the devise built in fragmentation sound. In addition, there is some clouding that can affect vision. This deficiency can be effectively countered by liberal use of irrigation, as with jell in place the chances of migration even with liberal irrigation are insignificant. Conclusions: Lidocaine jelly instillation proximal to ureteral calculi during lithotripsy using either pneumatic device or laser is an effective method of preventing retrograde stone displacement as well as significantly improving the stone-free rate. No competing financial interests exist. Runtime of video: 9 mins 59 secs

Tissue Fluid Pressure and Flow during Pneumatic Compression in Lymphedema of Lower Limbs

Physiotherapy of edema in cases with obstructed main lymphatics of lower limbs requires knowledge of how high external pressures should be applied manually or set in compression devices in order to generate tissue pressures high enough to move tissue fluid to nonswollen regions and to measure its flow rate. We measured tissue fluid pressure and flow in subcutaneous tissue of lymphedematous limbs stages II to IV at rest and during pneumatic compression under various pressures and inflation timing. An 8-chamber sequential compression device inflated to pressures 50-120 mmHg, for 50 sec each chamber, with no distal deflation, was used. Pressures were measured using a wick-in-needle and electronic manometer. Fluid flow was calculated from continuously recorded changes in limb circumference using strain gauge plethysmography. Before massage, in all stages of lymphedema, stagnant tissue fluid pressures in subcutaneous tissue ranged between -1 and +10 mmHg and did not differ from those measured in normal subjects. Pressures generated in tissue fluid by pneumatic compression reached 40-100 mmHg and were lower than those in inflated chambers. High pressure gradient through the skin was caused by its rigidity (fibrosis) and dissipation of applied compression force to proximal noncompressed limb regions. The calculated volumes of displaced tissue fluid ranged from 10 to 30 ml per compression cycle, to reach in some cases 100 ml in the groin region. Tissue fluid pressures generated by a pneumatic device were found lower than in the compression chambers. The obtained results point to the necessity of applying high pressures and longer compression times to generate effective tissue fluid pressures and to provide enough time for moving the stagnant fluid.