About

Dr. Alireza Ramezani is an Associate Professor specializing in the design and development of robots with nontrivial morphologies. His research focuses on the analysis and closed-loop feedback design of nonlinear systems, with particular emphasis on robot locomotion, including legged and fluidic-based systems. Additionally, his work explores robotics-inspired biology, integrating principles from biological systems into robotic design and control. Dr. Ramezani earned his PhD in Mechanical Engineering from the University of Michigan, Ann Arbor in 2014 under the advisement of J. Grizzle. Prior to that, he completed his MS in Mechanical Engineering at the Swiss Federal Institute of Technology (ETH) in 2010, advised by R. D’Andrea, and his BSc in Mechanical Engineering at Iran University of Science and Technology in 2007. His distinguished career has been recognized with numerous honors and awards, including the 2024 ASME Rising Star Award, the 2024 NSF CAREER award under the FRR program, and the 2024 Northeastern College of Engineering Impact Award. He has also been featured in two cover articles for Science (Robotics) Magazine and has a Science article ranked in the top 5% of all research outputs scored by the magazine's Altmetric. Dr. Ramezani was part of the Northeastern team that won the NASA ARTEMIS Award in 2022 and has received multiple NASA Game Changing Program Awards in 2020 and 2022. He also held a faculty research program position at NASA’s Jet Propulsion Lab (JPL) in 2022. His research contributions have been highlighted in prestigious outlets such as Nature, underscoring his impact in the field of robotics and nonlinear system design.

Research topics

• Medicine
• Ophthalmology
• Computer Science
• Surgery
• Optometry
• Optics
• Physics
• Anesthesia
• Internal medicine

Selected publications

• Safety and efficacy of limited laser therapy for type I mid-zone II retinopathy of prematurity

  BMC Ophthalmology · 2025-08-15

  articleOpen accessSenior author

  Laser photocoagulation of the entire avascular retina is a conventional therapy for the proliferative stage of retinopathy of prematurity (ROP). Limited lasers in number, localized at the avascular area posterior to the ridge might similarly regress aberrant retinal neovascularization. The study aims to evaluate the safety and efficacy of an innovative modified posterior half avascular area laser therapy for type I mid-zone II ROP. In a prospective comparative study, 48 eyes of 24 premature infants with bilateral symmetric type 1 zone II ROP were included for laser photocoagulation. The first eye received standard panavascular photocoagulation. In the second eye, laser photocoagulation was applied to the posterior half of the retinal avascular area, sparing the anterior half retinal avascular area. The retreatment rate was determined as a main outcome measure through weekly funduscopic examination. Fundus photography and refractive measurement were obtained at the last follow-up. The mean birth weight of the infants was 1341.04 ± 353.55 g. The infants’ mean postmenstrual age (PMA) at the time of intervention was 38.25 ± 2.95 weeks. In 2 (8.33%) infants, both eyes were retreated with complete regression without further recurrence. No adverse events were observed during mean PMA follow-up of 54.47 ± 4.09 weeks. The mean spherical equivalent was comparable between the two groups at the last follow-up (P = 0.794). Limited laser photocoagulation demonstrated a safety and efficacy profile similar to that of standard therapy in type I ROP in the mid-zone II. A randomized clinical trial is mandatory to validate the results.

  PublisherOA PDFDOI

• Management of chylous ascites following pancreaticoduodenectomy surgery using radiotherapy: A case report and review of literature

  International Journal of Surgery Case Reports · 2025-07-15

  articleOpen access

  INTRODUCTION: Chylous ascites (CA) is a rare but significant clinical complication that requires careful consideration for effective treatment. CA often results from cisterna chyli injury following abdominal surgeries, especially pancreaticoduodenectomy (PD), due to triglyceride-rich lymphatic fluid accumulation in the peritoneal cavity. Management of CA ranges from conservative approaches to interventional strategies, particularly in refractory cases. CASE PRESENTATION: A 76-year-old male who developed CA following PD for resectable ampulla of Vater cancer. Despite initial conservative treatments, including total parenteral nutrition (TPN), albumin supplementation, and octreotide administration, management of the patient's CA persisted with high-output ascitic drainage. DISCUSSION: Although conservative management is often effective, it may fail in cases of high-output or persistent CA. Radiotherapy, by inducing localized fibrosis and sealing lymphatic leaks, represents a safe and efficacious option for refractory cases. The literature underscores the importance of multidisciplinary, stepwise management that incorporates conservative, interventional, and surgical modalities for optimal patient outcomes. CONCLUSION: CA is an uncommon and challenging postoperative complication of PD that requires a multidisciplinary management strategy. Although conservative management is the first-line approach, this case highlights the potential role of radiotherapy as an effective and safe adjunctive therapy for refractory cases.

  PublisherDOI

• Thruster-Enhanced Locomotion: A Decoupled Model Predictive Control with Learned Contact Residuals

  2025-10-19

  articleSenior author

  Husky Carbon, a robot developed by Northeastern University, serves as a research platform to explore unification of posture manipulation and thrust vectoring. Unlike conventional quadrupeds, its joint actuators and thrusters enable enhanced control authority, facilitating thruster-assisted narrow-path walking. While a unified Model Predictive Control (MPC) framework optimizing both ground reaction forces and thruster forces could theoretically address this control problem, its feasibility is limited by the low torque-control bandwidth of the system’s lightweight actuators. To overcome this challenge, we propose a decoupled control architecture: a Raibert-type controller governs legged locomotion using position-based control, while an MPC regulates the thrusters augmented by learned Contact Residual Dynamics (CRD) to account for leg-ground impacts. This separation bypasses the torque-control rate bottleneck while retaining the thruster MPC to explicitly account for leg-ground impact dynamics through learned residuals. We validate this approach through both simulation and hardware experiments, showing that the decoupled control architecture with CRD performs more stable behavior in terms of push recovery and cat-like walking gait compared to the decoupled controller without CRD.

  PublisherDOI

• Reduced-Order Model-Based Gait Generation for Snake Robot Locomotion Using NMPC

  2025-05-19 · 2 citations

  articleSenior author

  This paper presents an optimization-based motion planning methodology for snake robots operating in constrained environments. By using a reduced-order model, the proposed approach simplifies the planning process, enabling the optimizer to autonomously generate gaits while constraining the robot's footprint within tight spaces. The method is validated through high-fidelity simulations that accurately model contact dynamics and the robot's motion. Key locomotion strategies are identified and further demonstrated through hardware experiments, including successful navigation through narrow corridors.

  PublisherDOI

• Estimation of Aerodynamics Forces in Dynamic Morphing Wing Flight

  2025-10-19

  articleSenior author

  Accurate estimation of aerodynamic forces is essential for advancing the control, modeling, and design of flapping-wing aerial robots with dynamic morphing capabilities. In this paper, we investigate two distinct methodologies for force estimation on Aerobat, a bio-inspired flapping-wing platform designed to emulate the inertial and aerodynamic behaviors observed in bat flight. Our goal is to quantify aerodynamic force contributions during tethered flight, a crucial step toward closed-loop flight control. The first method is a physics-based observer derived from Hamiltonian mechanics that leverages the concept of conjugate momentum to infer external aerodynamic forces acting on the robot. This observer builds on the system’s reduced-order dynamic model and utilizes real-time sensor data to estimate forces without requiring training data. The second method employs a neural network-based regression model, specifically a multi-layer perceptron (MLP), to learn a mapping from joint kinematics, flapping frequency, and environmental parameters to aerodynamic force outputs. We evaluate both estimators using a 6-axis load cell in a high-frequency data acquisition setup that enables fine-grained force measurements during periodic wingbeats. The conjugate momentum observer and the regression model demonstrate strong agreement across three force components (F<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf>, F<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</inf>, F<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">z</inf>).

  PublisherDOI

• Topical Fasudil in Type 2 Retinopathy of Prematurity: A Pilot Study

  Journal of Current Ophthalmology · 2025-01-01

  articleOpen access1st author

  Abstract Purpose: To evaluate the safety and effectiveness of topical fasudil drop, as a Rho kinase (ROCK) inhibitor agent, on type 2 retinopathy of prematurity (ROP). Methods: This comparative case series included 42 eyes of 21 premature infants with type 2 ROP. One eye of each patient was randomly assigned to receive a fasudil eye drop of 0.5% twice a day. The other eye received artificial tear drops twice a day as a control. The administration began at the time of prethreshold ROP diagnosis until 45 weeks of postmenstrual age. Funduscopic examination was performed weekly until complete retinal vascularization or progression into type 1 ROP. The extent of the retinal avascular area or progression into type 1 prethreshold ROP was compared between the two eyes of each infant. The influence of associated systemic conditions on the process of angiogenesis was also evaluated. Results: In 5 (23.8%) premature infants, reduction of the avascular zone area was observed in eyes treated with fasudil drop compared to the other eye ( P = 0.808). In 16 (76.2%) premature infants, no difference in the size of the avascular area was observed between the two eyes. None of the studied systemic factors influenced the reduction in the size of the avascular area, except for weight gain. However, the correlation between weight gain and reduction in avascular area size was only marginally significant ( P = 0.052). Conclusion: Topical 0.5% fasudil was safe, but showed no statistically significant benefit in reducing the avascular zone or preventing progression to type 1 ROP in this pilot study.

  PublisherDOI

• Automated Optic Disc Segmentation in Low-Quality Retinopathy of Prematurity Retinal Images

  2024-05-14

  article

  Premature infants are at risk of experiencing visual impairment primarily due to retinopathy of prematurity (ROP). Precise segmentation of the optic disc holds significant impact in determining the zone of ROP. Due to the imaging problems in premature infants and intricate nature of retinal fundus images, characterized by non-uniform illumination, low contrast between the background and the target area, the segmentation of the optic disc for infants poses a significant challenge, and there is limited literature reporting on this aspect. In addition to these challenges, the situation becomes more difficult when there are no annotations available. This paper introduces a method to tackle this issue by suggesting a semi-supervised dataset augmentation approach based on human feedback, aiming to enhance the performance of segmentation in images related to retinopathy of prematurity. VGG-Unet was set as the base model and these steps are iteratively implemented until further improvement in the result is unattainable. In this paper, two datasets were employed: (1) the publicly available Drishti dataset containing 101 fundus images from mature humans with corresponding annotations, and (2) private TMB dataset comprising 1054 images without any annotations. The VGG16-Unet model, when trained, faced challenges in effectively segmenting a specific dataset characterized by a significant distribution shift from the training dataset. Consequently, a method is required for segmenting TMB dataset without relying on expert retina specialists or annotated images. Our proposed approach aims to enhance segmentation performance by training the model on a public dataset and then applying it to the specific dataset. The first results without proposed method show the Jaccard score of 0.47 and Dice coefficient of 0.55. In proposed method after 3 epochs, we reach to the Jaccard score of 0.75 and accuracy of 0.85.

  PublisherDOI

• How Strong a Kick Should be to Topple Northeastern’s Tumbling Robot?

  2024-07-15 · 8 citations

  articleSenior author

  Rough terrain locomotion has remained one of the most challenging mobility questions. In 2022, NASA’s Innovative Advanced Concepts (NIAC) Program invited US academic institutions to participate NASA’s Breakthrough, Innovative & Game-changing (BIG) Idea competition by proposing novel mobility systems that can negotiate extremely rough terrain, lunar bumpy craters. In this competition, Northeastern University won NASA’s top Artemis Award award by proposing an articulated robot tumbler called COBRA (Crater Observing Bio-inspired Rolling Articulator). This report briefly explains the underlying principles that made COBRA successful in competing with other concepts ranging from cable-driven to multi-legged designs from six other participating US institutions.

  PublisherDOI

• Banking Turn of High-DOF Dynamic Morphing Wing Flight by Shifting Structure Response Using Optimization

  arXiv (Cornell University) · 2024-05-09

  preprintOpen accessSenior author

  The 3D flight control of a flapping wing robot is a very challenging problem. The robot stabilizes and controls its pose through the aerodynamic forces acting on the wing membrane which has complex dynamics and it is difficult to develop a control method to interact with such a complex system. Bats, in particular, are capable of performing highly agile aerial maneuvers such as tight banking and bounding flight solely using their highly flexible wings. In this work, we develop a control method for a bio-inspired bat robot, the Aerobat, using small low-powered actuators to manipulate the flapping gait and the resulting aerodynamic forces. We implemented a controller based on collocation approach to track a desired roll and perform a banking maneuver to be used in a trajectory tracking controller. This controller is implemented in a simulation to show its performance and feasibility.

  PublisherOA PDFDOI

• Narrow-Path, Dynamic Walking Using Integrated Posture Manipulation and Thrust Vectoring

  2024-07-15 · 1 citations

  article

  This research concentrates on enhancing the navigational capabilities of Northeastern University’s Husky, a multi-modal quadrupedal robot, that can integrate posture manipulation and thrust vectoring, to traverse through narrow pathways such as walking over pipes and slacklining. The Husky is outfitted with thrusters designed to stabilize its body during dynamic walking over these narrow paths. The project involves modeling the robot using the HROM (Husky Reduced-Order Model) and developing an optimal control framework. This framework is based on polynomial approximation of the HROM and a collocation approach to derive optimal thruster commands necessary for achieving dynamic walking on narrow paths. The effectiveness of the modeling and control design approach is validated through simulations conducted using Matlab.

  PublisherDOI

Frequent coauthors

• Mehdi Yaseri

  Tehran University of Medical Sciences

  76 shared

• Morteza Entezari

  Shahid Beheshti University of Medical Sciences

  73 shared

• Masoud Soheilian

  Shahid Beheshti University of Medical Sciences

  62 shared

• Hamid Ahmadieh

  Shahid Beheshti University of Medical Sciences

  42 shared

• Homayoun Nikkhah

  Shahid Beheshti University of Medical Sciences

  41 shared

• Gholam A. Peyman

  University of Phoenix

  33 shared

• Eric Sihite

  California Institute of Technology

  28 shared

• Siamak Moradian

  Shahid Beheshti University of Medical Sciences

  28 shared

Labs

• Silicon Synapse LabPI

Awards & honors

• 2024 ASME Rising Star Award
• 2024 NSF CAREER (FRR program)
• 2024 Northeastern College of Engineering Impact Award
• Two cover articles for Science (Robotics) Magazine
• One Science Article in the top 5% of all research outputs sc…