Needle Motion Research Articles

Haptic Teleoperation of Flexible Needles Combining 3D Ultrasound Guidance and Needle Tip Force Feedback

We present a haptic teleoperation system capable of steering flexible needles under ultrasound imaging toward a target. With respect to similar works, this approach enables intuitive control of the needle motion while providing the user with 3D navigation and needle tip cutting force using a combination of kinesthetic and vibrotactile haptic feedback. The needle is tracked during the insertion using a 3D ultrasound probe. A friction estimation algorithm extracts salient information about the cutting force at the needle tip from a force sensor placed at the needle base. A grounded haptic interface enables natural 6-DoF control of the needle motion while providing kinesthetic feedback, and a wearable cutaneous interface on the forearm provides distributed vibrotactile sensations. We carried out a human subject study to validate the insertion system in a gelatine phantom and compare seven different feedback techniques. The best performance was registered when providing navigation cues through kinesthetic feedback and needle tip cutting force through cutaneous vibrotactile feedback. In this modality, results showed an 87% accuracy improvement with respect to providing no haptic feedback at all.

Stability Analysis upon High-Pressure Common Rail Fuel Injection System under Multiple Injection Modes

Fuel injection stability of high-pressure common rail fuel injection system (HPCRFIS) under multiple injection modes is a recognized technical problem. To explain it essentially, a numerical model based on bond graph method, which provides a standardized series of symbol system to describe various components in different physical fields as well as interactive effect analysis tool for different energy categories, was used to investigate the problem. As HPCRFIS is a typical nonlinear system with multi-physical coupling, it is very difficult to analyze system stability directly. Therefore, the system was linearized at typical moments. The system matrix for each typical moment was obtained thereby. To investigate the influential mechanism of system stability deeply, the variations of rank and eigenvalues distributions of state matrices were analyzed. The results show that the rank of state matrices changes abruptly when the needle or control valve moves. In terms of system stability, the oscillation characteristics are subject to the movement of needle or control valve. The ending of the former injection causes the system to show damping oscillation characteristics before the latter injection starts. The motion of control valve makes more contribution to system stability than that of needle, which could be concluded by Lyapunov stability criterion.

Study on Cavitating Flow Inside Orifice and Spray Angle Near Nozzle Tip According to the Position of Needle Using Enlarged Transparent Acrylic Nozzle

This study aims to analyze effect of needle position inside nozzle on the internal and external flow characteristics. To visualize cavitating flow inside nozzle, the transparent acrylic nozzle was used. We tested five needle positions that simulated the needle movement of injector. The cross-section of test nozzle is rectangular with a very narrow width instead of circular shaped for a better visualization of cavitating flow. The inside of the nozzle was visualized by the shadowgraphic visualization using a high-speed camera and a metal-halide lamp. From the experiments, development of the cavitating flow according to the needle positions depends on the flow velocity and the cavitation number. The cavitation length, cavitation width, and spray angle are relatively symmetrically shown when the needle was at the center. However, they were asymmetrical when the needle position was biased. When the needle positions were in the same on the vertical line, the minimum cavitation length, minimum cavitation width, and minimum spray angle were larger when the upper level. The needle position affects the development timing and cavitation growth. When the needle position was located at the upper level, the hydraulic flip occurred at a higher injection pressure than the lower level.

Numerical simulation of fuel dribbling and nozzle wall wetting

The present work describes a numerical methodology and its experimental validation of the flow development inside and outside of the orifices during a pilot injection, dwelt time and the subsequent start of injection cycle. The compressible Navier-Stokes equations are numerically solved in a six-hole injector imposing realistic conditions of the needle valve movement and considering in addition a time-dependent eccentric motion. The valve motion is simulated using the immersed boundary method; this allows for simulations to be performed at zero lift during the dwelt time between successive injections, where the needle remains closed. Moreover, the numerical model utilises a fully compressible two-phase (liquid, vapour) two-component (fuel, air) barotropic model. The air’s motion is simulated with an additional transport equation coupled with the VOF interface capturing method able to resolve the near-nozzle atomisation and the resulting impact of the injected liquid on the oleophilic nozzle wall surfaces. The eccentric needle motion is found to be responsible for the formation of strong swirling flows inside the orifices, which not only contributes to the breakup of the injected liquid jet into ligaments but also to their backwards motion towards the external wall surface of the injector. Model predictions suggest that such nozzle wall wetting phenomena are more pronounced during the closing period of the valve and the re-opening of the nozzle, due to the residual gases trapped inside the nozzle, and which contribute to the poor atomisation of the injected fluid upon re-opening of the needle valve in subsequent injection events.

A Fluidic Soft Robot for Needle Guidance and Motion Compensation in Intratympanic Steroid Injections

Intratympanic steroid injections are commonly employed in treating ear diseases, such as sudden sensorineural hearing loss or Meniere's disease through drug delivery via the middle ear. Whilst being an effective treatment, the procedure has to be performed by a trained surgeon to avoid delicate regions in the patient's anatomy and is considered painful despite the use of topical anaesthesia. In this letter we introduce a fluid-driven soft robotic system which aims at increasing patient-comfort during the injection by counteracting unwanted needle motion, reducing the cognitive load of the clinician by autonomously identifying sensitive regions in the ear and de-risking the procedure by steering the needle towards the desired injection site. A design comprising of six embedded fluidic actuators is presented, which allow for translation and rotation of the needle as well as adaptive stiffening in the coupling between needle and ear canal. The system's steering-capabilities are investigated and the differential kinematics derived to demonstrate trajectory tracking in Cartesian space. A vision system is developed which enables tracking of anatomical landmarks on the tympanic membrane and thus locating the desired needle insertion site. The integrated system shows the ability to provide a safe guide for the inserted needle towards a desired target direction while significantly reducing needle motion. The proposed tracking algorithm is able to identify the desired needle insertion site and could be employed to avoid delicate anatomical regions.

The effect of transient needle lift on the internal flow and near-nozzle spray characteristics for modern GDI systems investigated by high-speed X-ray imaging

The development of the injector nozzle is a dynamic area in regard of several technical aspects. At first, the internal flow influences the near-field spray characteristics via various phenomena such as cavitation and turbulence. However, these phenomena are not fully understood due to their extremely fast, complex and multiscale nature. Furthermore, it governs the spray targeting inside the combustion chamber. High-speed X-ray imaging of GDI injector nozzles is performed in this study. The experimental results presented are related to the internal flow and primary breakup of discharged liquid jets. The injectors used are equipped with nozzles made of aluminum which have been specially developed for these investigations to enhance optical accessibility. The visualization of the needle motion, in-nozzle flow and the primary breakup region provides several exciting observations. First, the needle lift tracking exhibits short overshooting right before the steady-state of the injection phase. This event leads to a short-term, however, significant change in the associated performance of the breakup. This phenomenon is found to be a consequence of the transient behavior of the in-nozzle flow. It is shown that under some circumstances hydraulic flip may occur during this overshooting period. The primary jet breakup region is visualized and evaluated by means of image processing. Thus, the transient behavior of liquid jet expansion is quantified in the vicinity of the nozzle. It is observed that the liquid jet direction deviates from the hole axis already at the nozzle outlet, which is caused by internal flow characteristics.

Is Experience in Hemodialysis Cannulation Related to Expertise? A Metrics-based Investigation for Skills Assessment.

Cannulation is not only one of the most common medical procedures but also fraught with complications. The skill of the clinician performing cannulation directly impacts cannulation outcomes. However, current methods of teaching this skill are deficient, relying on subjective demonstrations and unrealistic manikins that have limited utility for skills training. Furthermore, of the factors that hinders effective continuing medical education is the assumption that clinical experience results in expertise. In this work, we examine if objective metrics acquired from a novel cannulation simulator are able to distinguish between experienced clinicians and established experts, enabling the measurement of true expertise. Twenty-two healthcare professionals, who practiced cannulation with varying experience, performed a simulated arteriovenous fistula cannulation task on the simulator. Four clinicians were peer-identified as experts while the others were designated to the experienced group. The simulator tracked the motion of the needle (via an electromagnetic sensor), rendered blood flashback function (via an infrared light sensor), and recorded pinch forces exerted on the needle (via force sensing elements). Metrics were computed based on motion, force, and other sensor data. Results indicated that, with near 80% of accuracy using both logistic regression and linear discriminant analysis, the objective metrics differentiated between experts and the experienced, including identifying needle motion and finger force as two prominent features that distinguished between the groups. Furthermore, results indicated that expertise was not correlated with years of experience, validating the central hypothesis of the study. These insights contribute to structured and standardized medical skills training by enabling a meaningful definition of expertise and could potentially lead to more effective skills training methods.

Scanning Tissue Oxygen Needle Probe.

A new device designed to scan oxygen partial pressure along a line in a biological tissue is described in this paper. The probe is housed in a stainless-steel needle. As opposed to other devices for oxygen scanning in tissue, the new probe does not require mechanical translation of the needle in the tissue. The probe includes an active sensing area along the needle shaft that can be scanned optically by an internal optical fiber. This feature allows for repeated scans of tissue oxygen along a line without translating the needle with respect to the tissue, thus avoiding tissue damage associated with needle motion. First, we describe the design of the device including its sensing mechanism, mechanical design, optical configuration, and signal processing. We then move on to describe the results of the device characterization and testing. Finally, we conclude by discussing possible applications of the device in research and in clinical diagnoses and treatment monitoring.

Calculation of shafts bending vibrations

This article deals with the problem of calculating the vibration of the details of high-speed non-woven fabric making machines. Methods: The brushes of the needle mechanisms of weaving machines provide direct needle movement. In the current machines, the needle rods are fixed to the beam. The brushes, in turn, are mounted on the shaft, which leads to the mechanism. Conclusion: When designing textile, light and cotton industrial machines, the dimensions of the parts and the materials for their manufacture should be chosen in such a way that the parts do not wear out and residual deformation under the influence of maximum stresses under normal operating conditions.

Determination of the stages of the injection process for Common Rail injectors using vibration pulses

The study and modeling of the combustion process of diesel engines require knowledge of the injection characteristics. The information on the exact start, duration and end of the injection is required. For Common Rail injectors with electromagnetic control, the beginning and duration of the electronic control pulse are precisely known. The actual start and duration of the injection are not the same as those of the impulse and they are related to the movement of the nozzle needle. The experimental determination of the movement of the nozzle needle requires specially prepared experimental installations and expensive measuring instruments. In addition, the experimental injector must be prepared with design modifications allowing the incorporation of sensors. The article presents a method for determining the start and duration of injection of Common Rail injectors using the registration and analysis of vibration pulses generated in the injector body. The method is based on the fact that the nozzle needle causes vibrations in the injector body when lifting and seating.

EXTH-21. INTRAINFUSION CATHETER MOVEMENT FACILITATES INCREASED INFUSATE VOLUME DISPERSED IN AGAROSE GEL

Abstract Glioblastoma has a 5 year survival of only 5.5% and a median patient survival of 12 to 15 months even with gold standard treatment. One potential method of improving treatment of glioblastoma is the use of convection-enhanced delivery (CED) which utilizes local delivery of therapeutics to the brain. However, clinical trials have shown an inability of standard catheters to deliver therapeutics to the entire target area. In this study, we explore the potential of controlled catheter movement to increase the volume dispersed (Vd) of indigo carmine dye in agarose gel brain tissue phantoms. We use four catheter control protocols: stationary, continuous retraction, continuous insertion, and intermittent insertion using a single port stepped catheter. The continuous retraction group resulted in consistent catheter clogging caused by the continued insertion of the catheter and therefore was removed from further analysis. Vd and backflow distance was quantified for all other catheter movement protocols using optical images captured throughout the infusion. Catheter retraction resulted in an increase in Vd of 51% while intermittent insertion resulted in a Vd increase of 24% compared to the stationary catheter. Additionally, a 37% reduction in backflow distance was seen with the retracting catheter when compared to the stationary catheter. These results are further supported by a simplified computational model that we have created. The computational model simulates the infusion of indigo carmine dye through an agarose gel brain tissue phantom and shows an increase in Vd of over 100% with catheter retraction. The increased Vd and decreased backflow distance afforded by the retracting catheter, suggests that the use of catheter movement may be a useful technique in increasing drug dispersal in tumorous tissue. Additional work in live and excised tissue should be conducted to confirm these results and an exploration of optimal needle movement protocols is necessary.

ДОСЛІДЖЕННЯ РЕЖИМІВ ЗАПУСКУ ДВИГУНА RT-FLEX

Starting modes are one of the most critical in the operation of marine diesel engines. Under the unsteady conditions of the flow of working processes, it is difficult to ensure their quality indicators. Of particular importance is the reliability in maneuvering. The foregoing relates, first of all, to fuel injection, which determines to a large extent the combustion process and all the operational characteristics of a diesel engine. Typical start-ups are the first fuel supply cycles [1], presented in Fig. 1 by the oscillograms of the nozzle needle movement. An oscillatory process is observed, accompanied by a partial rise of the needle. This increases the duration of injection, and an incomplete rise leads to a throttling of the fuel flow in the section under the needle. The atomization pressure decreases, the conditions of mixture formation deteriorate, which, along with the low parameters of the air charge, adversely affects the characteristics of the working process up to skipping the ignition.

Numerical investigation of transient hole-to-hole variation in cavitation regimes inside a multi-hole diesel nozzle

Dynamics of in-nozzle flow are known to have crucial impacts on the spray structure, and thus hole-to-hole variation in transient cavitating flow is strongly suspected of being a source of undesirable spray asymmetries. This study focuses on effects of the needle motion on evolution of in-nozzle cavitation regimes. For verifying the numerical models, simulation results obtained using the Winklhofer throttle “U” and the real-size two-hole optical nozzle were validated against available experimental data of mass flow rate at the nozzle exit and evolution of geometrical/string cavitation regions. Two different patterns of string cavitation defined as “needle” and “hole connecting” string cavitation were obtained in the optical experiments. Then the transient flow characteristics inside a five-hole injector nozzle were studied under needle lift and off-axis motion using the validated models. Results show that the “needle” string cavitation originated from the needle tip and/or hole exit and then developed into the orifice at lower needle lifts, and the “hole connecting” ones connecting orifices through the sac were tended to form at higher needle lifts with weaker intensity and shorter duration. Meanwhile, both “needle” and “hole connecting” string cavitation strongly depended on the structure and intensity of the in-nozzle vortex flow. Furthermore, both geometrical and string cavitation were tended to occur at lower needle lifts within the simulated five-hole injector, and all of the single-phase flow, string cavitation flow and geometrical cavitation flow regimes can simultaneously form in the hole 1, 2 and 3 respectively due to the needle lift and radial displacement.

Optical study on needle lift and its effects on reacting diesel sprays of a single hole solenoid injector

Precise control of needle lift provides one possibility to control the diesel spray and combustion process actively. However, most studies of needle lift focus on internal flow or near nozzle spray. Little work has been performed on its effects on reacting spray. In this work, one way to change the needle lift profile of a solenoid injector has been developed and the relationship between needle lift and reacting spray has been investigated. The needle movement was detected with an optical nozzle. In addition, the visualization of reacting sprays of the same injector equipped with a single hole nozzle was conducted in a combustion chamber. Some simulations were also performed to assist the analysis. The results show that the needle lift profile can be regulated by changing the thickness of an adjusting pad. It seems the different needle lift profiles do not bring in significant influences on reacting spray characteristics. The CFD results indicate that it is mainly caused by the similar internal flow characteristics which do not show strong variation when needle lift is higher than 0.1 mm. However, the discharge coefficient and velocity coefficient decrease sharply when needle lift is smaller than 0.05 mm because of the ?throttle? effect.

The Abnormal and Rapid Movement of Sewing Needle From Chest Toward Heart

: We herein introduced a 3 years old girl, who is a rare case of penetrating intracardiac damage severely induced by the abnormal movement of a sewing needle form the right lung toward the heart and entering in the right ventricle, which created Right Pneumothorax and right side bleeding. In clinical examinations, all vital symptoms were normal, and there was no sign of Cardiac tamponade, except reduced sound in the right lung base. Also, the external object was retained in the midclavicular line between the third rib, which was significant. In the Simple posterior-anterior and lateral graphics of chest radio opacity linear image on the lower part of the heart, the shadow was also significant. This is a rare case of abnormal needle movement from the right thorax to the right ventricular apex, which caused pulmonary problems. Following necessary diagnostic tests, a surgery was performed to remove the needle from the patient’s chest without open-heart surgery and CPB. Finally, 3 days after the operation, the patient was discharged from the cardiac surgery service in good general condition.

Modeling of diesel spray tip penetration during start-of-injection transients

Multiple-injection strategy that has been applied widely in diesel engines usually features a short duration for each injection pulse. As a result, the shortened injection makes the needle opening and closing transients increasingly important for spray in an injection event. Owing to the needle movement, the spray development during the transient processes is complex and quite different from the spray at the quasi-steady state. However, so far modeling of the spray development during the transient processes is far from adequate. Particularly, a theoretical zero-dimensional (0-D) spray tip penetration model considering the needle opening and sac pressurization processes as well as ambient and injection conditions during the start-of-injection (SOI) transients is still absent. In this paper, considering the sac pressurization processes, the 0-D model of spray tip penetration during the SOI transients is derived. Then, the model is validated against the experimental spray data using a long-distance microscope together with an ultrahigh speed CMOS camera. The model and experimental results show that the spray tip penetration shows a t3/2 dependence at the initial stage of injection rather than the t dependence suggested by Hiroyasu’s model. Later, the spray tip penetration shows a t3/4 dependence owing to the spray breakup, and a t1/2 dependence with the completion of sac pressurization. The models and analysis are believed to provide new insights into the transient spray behaviors and valuable reference for engineers and researchers who are considering the model-based development of next-generation diesel engines.

Investigations on the Spray-Atomization of Various Fuels for an Outwardly Opening Piezo Injector for the Application to a Pilot Injection Passenger Car Gas Engine

<div class="section abstract"><div class="htmlview paragraph">Pilot injection gas engines are commonly used as large stationary engines. Often, the combustion is implemented as a dual-fuel strategy, which allows both mixed and diesel-only operation, based on a diesel engine architecture. The current research project focuses on the application of pilot injection in an engine based on gasoline components of the passenger car segment, which are more cost-effective than diesel components. The investigated strategy does not aim for a diesel-only combustion, hence only small liquid quantities are used for the main purpose of providing a strong, reliable ignition source for the natural gas charge. This approach is mainly driven to provide a reliable alternative to the high spark ignition energies required for high cylinder charge densities.</div><div class="htmlview paragraph">When using such small liquid quantities, a standard common-rail diesel nozzle will apparently not be ideal regarding some general specifications. Due to this fact, an outwardly opening piezo injector is intended to be used due to its high performance in several aspects. An issue, which is almost unknown in literature, is the atomization behavior for fuel types differing significantly from the viscosity properties of regular gasoline fuel.</div><div class="htmlview paragraph">The aim of this publication is to clarify, whether the outwardly opening piezo injector can produce an atomization quality, which is sufficient to be used as a pilot injection ignition source for natural gas engines. The experimental results were obtained by means of a combined methodology using both Mie-scattering and PDA (Phase Doppler Anemometry) in a constant volume chamber. The injected masses showed a difference of up to 30% for the examined fuels, whereas liquid penetrations displayed a smaller difference. The Sauter Mean Diameters (SMD) for diesel-like fuels were 5…10μm larger compared to operation on gasoline-like fuels. Additionally, the needle motion for given actuation parameters was studied using a laser vibrometer. Influences of rail pressure, injector temperature, actuation time and reproducibility were investigated, showing that the injector has great reproducibility, but on the other hand requires a complex understanding of the actuation strategy in engine operation.</div></div>

Large eddy simulation of a double-injection cycle and the impact of the needle motion on the sac-volume flow characteristics of a single-orifice diesel injector

Study of the flow within diesel injector has gained in importance over the years as several authors have reported that the injector flow in the sac volume highly influenced the nozzle-flow characteristics at low lifts. Few studies have, however, characterized the sac volume and its dynamics. Thus, this paper reports on a numerical characterization of the needle displacement effects (static vs dynamic) on the internal flow of a sac-volume, single-hole diesel injector. To this end, a transient double-injection “closing-opening-closing-opening” cycle was simulated with a monophasic incompressible CFD model in combination with a moving mesh strategy to capture axial needle displacement. A large eddy simulation (LES) approach was chosen to gain better insight into the complexity of this unsteady turbulent flow. The emphasis of the paper is on the dynamic effects of needle movement on the sac flow, while static needle LES results are also shown to illustrate differences. The main findings reported herein are that the dynamic model shows a hysteresis effect associated with the needle motion between opening/closing phases. Quantitatively, the transient needle movement caused a difference in mass flow rate between the sac entrance and exit that was found to reach a maximum of [Formula: see text]. The hysteresis effect was found to be more pronounced at low needle lifts; both static and dynamic models seem to have performed similarly at very high needle lifts. Qualitatively, the LES sac-volume flow representations revealed a fuel jet attachment/detachment with needle movement, while static partial-lift simulations always predict an attached fuel jet. Further analysis of sac vortex dynamics revealed a high-energy vortex-structure breakdown just before the nozzle entrance that could help explain the higher turbulence production reported in the literature, both experimentally and numerically, at low needle lifts.

Bevel angle study of flexible hollow needle insertion into biological mimetic soft-gel: Simulation and experimental validation

BackgroundA thorough understanding of cutting-edge geometry and cutting forces of hollow biopsy needles are required to optimise needle tip design to improve fine needle aspiration procedures. ObjectivesTo incorporate the dynamics of needle motion in a model for flexible hollow bevel tipped needle insertion into a biological mimetic soft-gel using parameters obtained from experimental work. Additionally, the models will be verified against corresponding needle insertion experiments. MethodsTo verify simulation results, needle deflection and insertion forces were compared with corresponding experimental results acquired with an in-house developed needle insertion mechanical system. Additionally, contact stress distribution on needles from agar gel for various time scales were also studied. ResultsFor the 15°, 30°, 45°, 60° bevel angle needles, and 90° blunt needle, the percentage error in needle deflection of each needle compared to experiments, were 7.3%, 9.9%, 8.6%, 7.8%, and 9.7% respectively. Varying the bevel angle at the needle tip demonstrates that the needle with a lower bevel angle produces the largest deflection, although the insertion force does not vary too much among the tested bevel angles. ConclusionThis experimentally verified computer-based simulation model could be used as an alternative tool for better understanding the needle-tissue interaction to optimise needle tip design towards improved biopsy efficiency.

The Effects of Laryngoscope Shape and Needle Position on Distal Airway Pressure in Jet Ventilation.

Laryngoscopes and subglottiscopes of multiple shapes and lengths are used in airway surgery to maintain an open airway; protect the trachea; and provide a place to mount the light, evacuator, and ventilation needle. Despite differences in scopes and ventilation needle mounting positions, the same jet pressures are typically used. We hypothesized that different scopes and scope configurations would affect distal airway pressure magnitude and homogeneity. A laboratory investigation of distal airway pressures in a lung modelduring low frequency jet ventilation. A three-dimensional airway model based on the computed tomography scan of a 15-year old healthy male was fabricated with pressure transducers at the fifth airway generation. A laryngoscope and a subglottiscope were each mounted in the model coaxial with the trachea. Parameters including scope depth and needle mounting position were adjusted, and the effects on distal airway pressure were recorded. Changing the scope depth from 1 to 3 cm past the laryngeal inlet had a limited effect on distal airway pressure. Needle mounting angle in the laryngoscope strongly influenced distal airway pressure, with a 7° angle change yielding a 67.5% increase. Compared to a loose needle centered in the trachea 1 cm past the laryngeal inlet, the subglottiscope and laryngoscope showed up to 16% and 150% increases in distal airway pressure, respectively. Different scopes or changes in the configuration, such as the needle angle, strongly influence distal airway pressure. Our findings indicate that different jet pressures are required for different scopes and that a stable needle mount is a critical design consideration to prevent changes in minute ventilation due to needle movement. NA (Basic Research) Laryngoscope, 131:E354-E357, 2021.