Actuation Pressure

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William Yang - One of the best experts on this subject based on the ideXlab platform.

  • measurements of droplet size distribution and analysis of nasal spray atomization from different Actuation Pressure
    Journal of Aerosol Medicine and Pulmonary Drug Delivery, 2015
    Co-Authors: Kiao Inthavong, Man Chiu Fung, William Yang
    Abstract:

    Abstract Background: To evaluate the deposition efficiency of spray droplets in a nasal cavity produced from a spray device, it is important to determine droplet size distribution, velocity, and its dispersion during atomization. Due to the limiting geometric dimensions of the nasal cavity airway, the spray plume cannot develop to its full size inside the nasal vestibule to penetrate the nasal valve region for effective drug deposition. Methods: Particle/droplet image analysis was used to determine local mean droplet sizes at eight regions within the spray plume under different Actuation Pressures that represent typical hand operation from pediatric to adult patients. Results: The results showed that higher Actuation Pressure produces smaller droplets in the atomization. Stronger Actuation Pressure typical of adult users produces a longer period of the fully atomized spray stage, despite a shorter overall spray duration. This produces finer droplets when compared with the data obtained by weaker Actuation...

  • High Resolution Visualization and Analysis of Nasal Spray Drug Delivery
    Pharmaceutical Research, 2014
    Co-Authors: Kiao Inthavong, Man Chiu Fung, Xuwen Tong, William Yang
    Abstract:

    Purpose Effective nasal drug delivery of new-generation systemic drugs requires efficient devices that can achieve targeted drug delivery. It has been established that droplet size, spray plume, and droplet velocity are major contributors to drug deposition. Continual effort is needed to better understand and characterise the physical mechanisms underpinning droplet formation from nasal spray devices. Methods High speed laser photography combined with an in-house designed automated Actuation system, and a highly precise traversing unit, measurements and images magnified in small field-of-view regions within the spray was performed. Results The qualitative results showed a swirling liquid sheet at the near-nozzle region as the liquid is discharged before ligaments of fluid are separated off the liquid sheet. Droplets are formed and continue to deform as they travel downstream at velocities of up to 20 m/s. Increase in Actuation Pressure produces more rapid atomization and discharge time where finer droplets are produced. Conclusions The results suggest that device designs should consider reducing droplet inertia to penetrate the nasal valve region, but find a way to deposit in the main nasal passage and not escape through to the lungs.

  • Measurements of droplet size distribution and analysis of nasal spray atomization from different Actuation Pressure.
    Journal of aerosol medicine and pulmonary drug delivery, 2014
    Co-Authors: Kiao Inthavong, Man Chiu Fung, William Yang
    Abstract:

    To evaluate the deposition efficiency of spray droplets in a nasal cavity produced from a spray device, it is important to determine droplet size distribution, velocity, and its dispersion during atomization. Due to the limiting geometric dimensions of the nasal cavity airway, the spray plume cannot develop to its full size inside the nasal vestibule to penetrate the nasal valve region for effective drug deposition. Particle/droplet image analysis was used to determine local mean droplet sizes at eight regions within the spray plume under different Actuation Pressures that represent typical hand operation from pediatric to adult patients. The results showed that higher Actuation Pressure produces smaller droplets in the atomization. Stronger Actuation Pressure typical of adult users produces a longer period of the fully atomized spray stage, despite a shorter overall spray duration. This produces finer droplets when compared with the data obtained by weaker Actuation Pressure, typical of pediatric users. The experimental technique presented is able to capture a more complete representation of the droplet size distribution and the atomization process during an Actuation. The measured droplet size distribution produced can be related to the empirically defined deposition efficiency curve of the nasal cavity, allowing a prediction of the likely deposition.

Kiao Inthavong - One of the best experts on this subject based on the ideXlab platform.

  • measurements of droplet size distribution and analysis of nasal spray atomization from different Actuation Pressure
    Journal of Aerosol Medicine and Pulmonary Drug Delivery, 2015
    Co-Authors: Kiao Inthavong, Man Chiu Fung, William Yang
    Abstract:

    Abstract Background: To evaluate the deposition efficiency of spray droplets in a nasal cavity produced from a spray device, it is important to determine droplet size distribution, velocity, and its dispersion during atomization. Due to the limiting geometric dimensions of the nasal cavity airway, the spray plume cannot develop to its full size inside the nasal vestibule to penetrate the nasal valve region for effective drug deposition. Methods: Particle/droplet image analysis was used to determine local mean droplet sizes at eight regions within the spray plume under different Actuation Pressures that represent typical hand operation from pediatric to adult patients. Results: The results showed that higher Actuation Pressure produces smaller droplets in the atomization. Stronger Actuation Pressure typical of adult users produces a longer period of the fully atomized spray stage, despite a shorter overall spray duration. This produces finer droplets when compared with the data obtained by weaker Actuation...

  • High Resolution Visualization and Analysis of Nasal Spray Drug Delivery
    Pharmaceutical Research, 2014
    Co-Authors: Kiao Inthavong, Man Chiu Fung, Xuwen Tong, William Yang
    Abstract:

    Purpose Effective nasal drug delivery of new-generation systemic drugs requires efficient devices that can achieve targeted drug delivery. It has been established that droplet size, spray plume, and droplet velocity are major contributors to drug deposition. Continual effort is needed to better understand and characterise the physical mechanisms underpinning droplet formation from nasal spray devices. Methods High speed laser photography combined with an in-house designed automated Actuation system, and a highly precise traversing unit, measurements and images magnified in small field-of-view regions within the spray was performed. Results The qualitative results showed a swirling liquid sheet at the near-nozzle region as the liquid is discharged before ligaments of fluid are separated off the liquid sheet. Droplets are formed and continue to deform as they travel downstream at velocities of up to 20 m/s. Increase in Actuation Pressure produces more rapid atomization and discharge time where finer droplets are produced. Conclusions The results suggest that device designs should consider reducing droplet inertia to penetrate the nasal valve region, but find a way to deposit in the main nasal passage and not escape through to the lungs.

  • Measurements of droplet size distribution and analysis of nasal spray atomization from different Actuation Pressure.
    Journal of aerosol medicine and pulmonary drug delivery, 2014
    Co-Authors: Kiao Inthavong, Man Chiu Fung, William Yang
    Abstract:

    To evaluate the deposition efficiency of spray droplets in a nasal cavity produced from a spray device, it is important to determine droplet size distribution, velocity, and its dispersion during atomization. Due to the limiting geometric dimensions of the nasal cavity airway, the spray plume cannot develop to its full size inside the nasal vestibule to penetrate the nasal valve region for effective drug deposition. Particle/droplet image analysis was used to determine local mean droplet sizes at eight regions within the spray plume under different Actuation Pressures that represent typical hand operation from pediatric to adult patients. The results showed that higher Actuation Pressure produces smaller droplets in the atomization. Stronger Actuation Pressure typical of adult users produces a longer period of the fully atomized spray stage, despite a shorter overall spray duration. This produces finer droplets when compared with the data obtained by weaker Actuation Pressure, typical of pediatric users. The experimental technique presented is able to capture a more complete representation of the droplet size distribution and the atomization process during an Actuation. The measured droplet size distribution produced can be related to the empirically defined deposition efficiency curve of the nasal cavity, allowing a prediction of the likely deposition.

Man Chiu Fung - One of the best experts on this subject based on the ideXlab platform.

  • measurements of droplet size distribution and analysis of nasal spray atomization from different Actuation Pressure
    Journal of Aerosol Medicine and Pulmonary Drug Delivery, 2015
    Co-Authors: Kiao Inthavong, Man Chiu Fung, William Yang
    Abstract:

    Abstract Background: To evaluate the deposition efficiency of spray droplets in a nasal cavity produced from a spray device, it is important to determine droplet size distribution, velocity, and its dispersion during atomization. Due to the limiting geometric dimensions of the nasal cavity airway, the spray plume cannot develop to its full size inside the nasal vestibule to penetrate the nasal valve region for effective drug deposition. Methods: Particle/droplet image analysis was used to determine local mean droplet sizes at eight regions within the spray plume under different Actuation Pressures that represent typical hand operation from pediatric to adult patients. Results: The results showed that higher Actuation Pressure produces smaller droplets in the atomization. Stronger Actuation Pressure typical of adult users produces a longer period of the fully atomized spray stage, despite a shorter overall spray duration. This produces finer droplets when compared with the data obtained by weaker Actuation...

  • High Resolution Visualization and Analysis of Nasal Spray Drug Delivery
    Pharmaceutical Research, 2014
    Co-Authors: Kiao Inthavong, Man Chiu Fung, Xuwen Tong, William Yang
    Abstract:

    Purpose Effective nasal drug delivery of new-generation systemic drugs requires efficient devices that can achieve targeted drug delivery. It has been established that droplet size, spray plume, and droplet velocity are major contributors to drug deposition. Continual effort is needed to better understand and characterise the physical mechanisms underpinning droplet formation from nasal spray devices. Methods High speed laser photography combined with an in-house designed automated Actuation system, and a highly precise traversing unit, measurements and images magnified in small field-of-view regions within the spray was performed. Results The qualitative results showed a swirling liquid sheet at the near-nozzle region as the liquid is discharged before ligaments of fluid are separated off the liquid sheet. Droplets are formed and continue to deform as they travel downstream at velocities of up to 20 m/s. Increase in Actuation Pressure produces more rapid atomization and discharge time where finer droplets are produced. Conclusions The results suggest that device designs should consider reducing droplet inertia to penetrate the nasal valve region, but find a way to deposit in the main nasal passage and not escape through to the lungs.

  • Measurements of droplet size distribution and analysis of nasal spray atomization from different Actuation Pressure.
    Journal of aerosol medicine and pulmonary drug delivery, 2014
    Co-Authors: Kiao Inthavong, Man Chiu Fung, William Yang
    Abstract:

    To evaluate the deposition efficiency of spray droplets in a nasal cavity produced from a spray device, it is important to determine droplet size distribution, velocity, and its dispersion during atomization. Due to the limiting geometric dimensions of the nasal cavity airway, the spray plume cannot develop to its full size inside the nasal vestibule to penetrate the nasal valve region for effective drug deposition. Particle/droplet image analysis was used to determine local mean droplet sizes at eight regions within the spray plume under different Actuation Pressures that represent typical hand operation from pediatric to adult patients. The results showed that higher Actuation Pressure produces smaller droplets in the atomization. Stronger Actuation Pressure typical of adult users produces a longer period of the fully atomized spray stage, despite a shorter overall spray duration. This produces finer droplets when compared with the data obtained by weaker Actuation Pressure, typical of pediatric users. The experimental technique presented is able to capture a more complete representation of the droplet size distribution and the atomization process during an Actuation. The measured droplet size distribution produced can be related to the empirically defined deposition efficiency curve of the nasal cavity, allowing a prediction of the likely deposition.

Dragan Aleksendrić - One of the best experts on this subject based on the ideXlab platform.

  • Neuro-genetic optimization of disc brake performance at elevated temperatures
    FME Transaction, 2014
    Co-Authors: Velimir Ćirović, Dusan Smiljanic, Dragan Aleksendrić
    Abstract:

    The basic problem of automotive brakes operation is the decreasing of their performance at elevated temperatures in the contact of friction pair (brake disc and brake pad). Increasing of the brake interface temperature often causes decreasing of braking torque during a braking cycle. In order to provide the stable level of braking torque during a braking cycle, the neural network based optimization model of the disc brake performance has been developed. The dynamic neural networks have been employed for modelling of complex synergy of tribological phenomena that affects the final disc brake performance at elevated temperatures. The dynamic optimization neural network model of disc brake performance at elevated temperatures has been developed using recurrent neural networks. It predicts the braking torque versus the dynamic change of the brake Actuation Pressure, sliding speed and the brake interface temperature in a braking cycle. Genetic algorithms were integrated with the neural network model for optimization of the brake Actuation Pressure in order to obtain the desired level of braking torque. This hybrid, neuro-genetic model was successfully used in optimization of the brake hydraulic Pressure level needed to achieve the maximum and stable brake performance during a braking cycle.

  • Microcontroller based Control of Disc Brake Actuation Pressure
    SAE Technical Paper Series, 2013
    Co-Authors: Dragan Aleksendrić, Velimir Ćirović, Zivana Jakovljevic
    Abstract:

    Monitoring, modeling, prediction, and control of the braking process is a difficult task due to a complex interaction between the brake contact surfaces (disc pads and brake disc). It is caused by different influences of braking regimes and brake operation conditions on its performance. Faster and better control of the braking process is extremely important in order to provide harmonization of the generated braking torque with the tire-road adhesion conditions. It has significant influence on the stopping distance. The control of the braking process should be based on monitoring of the previous and current values of parameters that have influence on the brake performance. Primarily, it is related to the disc brake Actuation Pressure, the vehicle speed, and the brake interface temperature. The functional relationship between braking regimes and braking torque has to be established and continuously adapted according to the change of mentioned influencing factors. In this paper dynamic neural networks have been used for the purpose of modeling and control of the disc brake Actuation Pressure. Parameters of the developed dynamic neural model were used to build a program for implementation in a microcontroller. Recurrent neural networks have been implemented in 8-bit CMOS microcontroller for control of the disc brake Actuation Pressure. Two different models have been developed and integrated into the microcontroller. The first model was used for modeling and prediction of the braking torque. Based on that, the second inverse neural model, has been developed able to predict the brake Actuation Pressure needed for achieving previously selected (desired) braking torque value.

  • Adaptive neuro-fuzzy wheel slip control
    Expert Systems with Applications, 2013
    Co-Authors: Velimir Ćirović, Dragan Aleksendrić
    Abstract:

    Abstract Due to complex and nonlinear dynamics of a braking process and complexity in the tire–road interaction, the control of automotive braking systems performance simultaneously with the wheel slip represents a challenging problem. The non-optimal wheel slip level during braking, causing inability to achieve the desired tire–road friction force strongly influences the braking distance. In addition, steerability and maneuverability of the vehicle could be disturbed. In this paper, an active neuro-fuzzy approach has been developed for improving the wheel slip control in the longitudinal direction of the commercial vehicle. The dynamic neural network has been used for prediction and an adaptive control of the brake Actuation Pressure, during each braking cycle, according to the identified maximum adhesion coefficient between the wheel and road surface. The brake Actuation Pressure was dynamically adjusted on the level that provides the optimal level of the longitudinal wheel slip vs. the brake Pressure selected by driver, the current vehicle speed, the brake interface temperature, vehicle load conditions, and the current value of longitudinal wheel slip. Thus the dynamic neural network model operates (learn, generalize and predict) on-line during each braking cycle, fuzzy logic has been integrated with the neural model as a support to the neural controller control actions in the case when prediction error of the dynamic neural model reached the predefined value. The hybrid control approach presented here provided intelligent dynamic model – based control of the brake Actuation Pressure in order to keep the longitudinal wheel slip on the optimum level during a braking cycle.

  • Intelligent control of braking process
    Expert Systems with Applications, 2012
    Co-Authors: Dragan Aleksendrić, Ivana Vlatkovic Jakovljevic, Velimir Irović
    Abstract:

    Intelligent modeling, prediction and control of the braking process are not an easy task if using classical modeling techniques, regarding its complexity. In this paper, the new approach has been proposed for easy and effective monitoring, modeling, prediction, and control of the braking process i.e. the brake performance during a braking cycle. The context based control of the disc brake Actuation Pressure was used for improving the dynamic control of braking process versus influence of the previous and current values of the disc brake Actuation Pressure, the vehicle speed, and the brake interface temperature. For these purposes, two different dynamic neural models have been developed and integrated into the microcontroller. Microcontrollers are resource intensive and cost effective platforms that offer possibilities to associate with commonly used artificial intelligence techniques. The neural models, based on recurrent dynamic neural networks, are implemented in 8-bit CMOS microcontroller for control of the disc brake Actuation Pressure during a braking cycle. The first neural model was used for modeling and prediction of the braking process output (braking torque). Based on such acquired knowledge about the real brake operation, the inverse neural model has been developed which was able to predict the brake Actuation Pressure needed for achieving previously selected (desired) braking torque value in accordance with the previous and current influence of the Pressure, speed, and the brake interface temperature. Both neural models have had inherent abilities for on-line learning and prediction during each braking cycle and an intelligent adaptation to the change of influences of Pressure, speed, and temperature on the braking process.

Jerry Ying Hsi Fuh - One of the best experts on this subject based on the ideXlab platform.

  • ICCA - Investigation on Developing a Topology Optimized and 3D Printable Multimaterial Soft Gripper
    2018 IEEE 14th International Conference on Control and Automation (ICCA), 2018
    Co-Authors: Hongying Zhang, A. Senthil Kumar, Jerry Ying Hsi Fuh, Michael Yu Wang
    Abstract:

    This paper proposes a systemic design and fabrication approach to automatically develop multimaterial soft robots. Composing of relatively softer and harder materials, these robots are expected to undergo larger deformation and exert higher payloads. However, it is more challenging to design such kind of robots by biomimetic or intuitive approach because of a larger design space comparing with their single-material counterparts. Herein, the structural design problem is recast as a topology optimization one, for example, a soft gripper can be modeled as a compliant mechanism aiming to achieve its maximal bending deflection. During the optimization process, both structure and material distribution are obtained automatically. Thereafter, the optimized multimaterial soft gripper is directly fabricated by 3D printing technique regardless of geometrical complexity and material composition. Characterization and grasping tests show that a single finger can undergo 17.15° free travel bending and exert 0.13 N grasping force under 0.02 MPa Actuation Pressure. The proposed systemic approach is strongly recommended to develop other types of soft robots by defining the corresponding topology optimization model.

  • IROS - Design and development of a soft gripper with topology optimization
    2017 IEEE RSJ International Conference on Intelligent Robots and Systems (IROS), 2017
    Co-Authors: Hongying Zhang, Michael Yu Wang, A. Senthil Kumar, Feifei Chen, Yiqiang Wang, Jerry Ying Hsi Fuh
    Abstract:

    Soft robots, primarily made out of intrinsically soft materials, have flourished greatly in the past decade due to their advantages such as flexibility and adaptability over rigid-bodied robots. A rich repertoire of soft robots designed from intuitive or biomimetic approaches have been developed to provide new solutions for robots. However, these design approaches are limited by the designers' experience and inspiration, and a systematic design methodology for soft robots is still missing. We tackle this issue by mathematically recasting the design problem under the framework of topology optimization problem. To demonstrate the effectiveness of the proposed methodology, in this paper, we develop a pneumatically actuated soft gripper consisting of three fingers, each finger is able to undergo a free travel bending and deliver a grasping force. Hence, each gripper finger is designed as a continuum compliant mechanism to achieve its maximal bending deformation. The proposed soft gripper with complex shape is directly fabricated through 3D printing technology. Experimental results show that the deflected soft finger is able to achieve a 41° free travel bending and generate 0.68N blocked force upon 0.11MPa Actuation Pressure. This work represents an important step towards the goal of designing soft robots automatically.