Real-Time Ultrasound Doppler Tracking and Autonomous Navigation of a Miniature Helical Robot for Accelerating Thrombolysis in Dynamic Blood Flow

ACS Nano ◽  
2022 ◽  
Author(s):  
Qianqian Wang ◽  
Xingzhou Du ◽  
Dongdong Jin ◽  
Li Zhang
Keyword(s):  
Blood Flow ◽  
Real Time ◽  
Autonomous Navigation ◽  
Ultrasound Doppler ◽  
Doppler Tracking

scholarly journals Ultrasound Doppler-guided real-time navigation of a magnetic microswarm for active endovascular delivery

2021 ◽  
Vol 7 (9) ◽  
pp. eabe5914 ◽  
Author(s):  
Qianqian Wang ◽  
Kai Fung Chan ◽  
Kathrin Schweizer ◽  
Xingzhou Du ◽  
Dongdong Jin ◽  
...  
Keyword(s):  
Blood Flow ◽  
Real Time ◽  
Targeted Delivery ◽  
Ex Vivo ◽  
Dynamic Environments ◽  
Doppler Imaging ◽  
Great Promise ◽  
Mean Velocity ◽  
Ultrasound Doppler ◽  
Flowing Blood

Swarming micro/nanorobots offer great promise in performing targeted delivery inside diverse hard-to-reach environments. However, swarm navigation in dynamic environments challenges delivery capability and real-time swarm localization. Here, we report a strategy to navigate a nanoparticle microswarm in real time under ultrasound Doppler imaging guidance for active endovascular delivery. A magnetic microswarm was formed and navigated near the boundary of vessels, where the reduced drag of blood flow and strong interactions between nanoparticles enable upstream and downstream navigation in flowing blood (mean velocity up to 40.8 mm/s). The microswarm-induced three-dimensional blood flow enables Doppler imaging from multiple viewing configurations and real-time tracking in different environments (i.e., stagnant, flowing blood, and pulsatile flow). We also demonstrate the ultrasound Doppler–guided swarm formation and navigation in the porcine coronary artery ex vivo. Our strategy presents a promising connection between swarm control and real-time imaging of microrobotic swarms for localized delivery in dynamic environments.

1618: Real-Time Monitoring of Nitric Oxide and Blood Flow During Ischemia-Reperfusion in the Rat Testis

2006 ◽  
Vol 175 (4S) ◽  
pp. 521-521
Author(s):  
Motoaki Saito ◽  
Tomoharu Kono ◽  
Yukako Kinoshita ◽  
Itaru Satoh ◽  
Keisuke Satoh
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Real Time ◽  
Ischemia Reperfusion ◽  
Real Time Monitoring ◽  
Rat Testis

Hybrid MPI-MRI System for Dual-Modal In Situ Cardiovascular Assessments of Real-Time 3D Blood Flow Quantification—A Pre-Clinical In Vivo Feasibility Investigation

2020 ◽  
Vol 39 (12) ◽  
pp. 4335-4345
Author(s):  
Jochen Franke ◽  
Nicoleta Baxan ◽  
Heinrich Lehr ◽  
Ulrich Heinen ◽  
Sebastian Reinartz ◽  
...  
Keyword(s):  
Blood Flow ◽  
Real Time ◽  
Flow Quantification ◽  
Blood Flow Quantification

scholarly journals Deep Reinforcement Learning for End-to-End Local Motion Planning of Autonomous Aerial Robots in Unknown Outdoor Environments: Real-Time Flight Experiments

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2534
Author(s):  
Oualid Doukhi ◽  
Deok-Jin Lee
Keyword(s):  
Reinforcement Learning ◽  
Real Time ◽  
Autonomous Navigation ◽  
Control Technique ◽  
Local Motion ◽  
Aerial Robots ◽  
Novel Approach ◽  
Outdoor Environments ◽  
Aerial Vehicle ◽  
High Level

Autonomous navigation and collision avoidance missions represent a significant challenge for robotics systems as they generally operate in dynamic environments that require a high level of autonomy and flexible decision-making capabilities. This challenge becomes more applicable in micro aerial vehicles (MAVs) due to their limited size and computational power. This paper presents a novel approach for enabling a micro aerial vehicle system equipped with a laser range finder to autonomously navigate among obstacles and achieve a user-specified goal location in a GPS-denied environment, without the need for mapping or path planning. The proposed system uses an actor–critic-based reinforcement learning technique to train the aerial robot in a Gazebo simulator to perform a point-goal navigation task by directly mapping the noisy MAV’s state and laser scan measurements to continuous motion control. The obtained policy can perform collision-free flight in the real world while being trained entirely on a 3D simulator. Intensive simulations and real-time experiments were conducted and compared with a nonlinear model predictive control technique to show the generalization capabilities to new unseen environments, and robustness against localization noise. The obtained results demonstrate our system’s effectiveness in flying safely and reaching the desired points by planning smooth forward linear velocity and heading rates.

scholarly journals COLREG-Compliant Optimal Path Planning for Real-Time Guidance and Control of Autonomous Ships

2021 ◽  
Vol 9 (4) ◽  
pp. 405
Author(s):  
Raphael Zaccone
Keyword(s):  
Path Planning ◽  
Real Time ◽  
Collision Avoidance ◽  
Autonomous Navigation ◽  
Optimal Path ◽  
Open Water ◽  
Optimal Path Planning ◽  
Guidance And Control ◽  
Real Time Applications ◽  
And Control

While collisions and groundings still represent the most important source of accidents involving ships, autonomous vessels are a central topic in current research. When dealing with autonomous ships, collision avoidance and compliance with COLREG regulations are major vital points. However, most state-of-the-art literature focuses on offline path optimisation while neglecting many crucial aspects of dealing with real-time applications on vessels. In the framework of the proposed motion-planning, navigation and control architecture, this paper mainly focused on optimal path planning for marine vessels in the perspective of real-time applications. An RRT*-based optimal path-planning algorithm was proposed, and collision avoidance, compliance with COLREG regulations, path feasibility and optimality were discussed in detail. The proposed approach was then implemented and integrated with a guidance and control system. Tests on a high-fidelity simulation platform were carried out to assess the potential benefits brought to autonomous navigation. The tests featured real-time simulation, restricted and open-water navigation and dynamic scenarios with both moving and fixed obstacles.

Pulpal Blood Flow Measurement with Ultrasound Doppler Imaging

2010 ◽  
Vol 36 (3) ◽  
pp. 419-422 ◽  
Author(s):  
Min-Jung Yoon ◽  
Euiseong Kim ◽  
Seoung-Jong Lee ◽  
Young-Min Bae ◽  
Sergey Kim ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Measurement ◽  
Doppler Imaging ◽  
Blood Flow Measurement ◽  
Ultrasound Doppler ◽  
Pulpal Blood Flow
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