Adaptive Hybrid Control Algorithm With Iterative Learning for Robotic In Vitro Biomechanical Testing of Spine

2012 ◽  
Author(s):  
T. F. Bonner ◽  
L. Gilbertson ◽  
R. W. Colbrunn
Keyword(s):  
Control Algorithm ◽  
Degrees Of Freedom ◽  
Hybrid Control ◽  
Dynamic Testing ◽  
Biomechanical Testing ◽  
Testing Methods ◽  
Robotic Technology ◽  
Control Schemes ◽  
Pure Moment

In spine testing, methods have been developed to apply pure moments to a single axis of the spine to elucidate the mechanical properties of the spine. The application of those concepts continues to be applied with custom loading frames, custom robotics systems, and adaptation of commercial robotic technology. With these systems and pure moment testing, spinal biomechanics variables such as the neutral zone and range of motion can be determined. As more complex testing systems with higher degrees of freedom (DOF) capabilities are developed, dynamic testing becomes a possibility. However, these more complex testing systems require more complex control schemes.

scholarly journals A Physiological Dynamic Testing Machine for the Elbow Joint

2013 ◽  
Vol 7 (1) ◽  
pp. 78-85
Author(s):  
Johannes Kiene ◽  
Robert Wendlandt ◽  
Marcus Heinritz ◽  
Angelika Schall ◽  
Arndt-Peter Schulz
Keyword(s):  
Elbow Joint ◽  
Degrees Of Freedom ◽  
Dynamic Testing ◽  
Testing Machine ◽  
Biomechanical Testing ◽  
Trauma Surgery ◽  
Force Transmission ◽  
Pneumatic Actuators

Background: The aim of our study was to develop a test setup combining realistic force transmission with physiological movement patterns at a frequency that mimicked daily use of the elbow, to assess implants in orthopedic joint reconstruction and trauma surgery. Methods: In a multidisciplinary approach, an in vitro biomechanical testing machine was developed and manufactured that could simulate the repetitive forceful movement of the human elbow joint. The construction involved pneumatic actuators. An aluminum forearm module enabled movements in 3 degrees of freedom, while motions and forces were replicated via force and angular sensors that were similar to in vivo measurements. Results: In the initial testing, 16 human elbow joint specimens were tested at 35 Nm in up to 5000 cycles at a range of 10° extension to 110° flexion. The transmitted forces led to failure in 9 out of the 16 tested specimens, significantly more often in females and small specimens. Conclusions: It is possible to construct a testing machine to simulate nearly physiological repetitive elbow motions. The prototype has a number of technical deficiencies that could be modified. When testing implants for the human elbow with cadaver specimens, the specimen has to be chosen according to the intended use of the implant under investigation.

scholarly journals Robust Hybrid Control Algorithm for Tuning the Altitude and Attitude of Unmanned Aerial Vehicle

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Bohang Wang ◽  
Daobo Wang
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Control Algorithm ◽  
Degrees Of Freedom ◽  
Hybrid Control ◽  
Pole Placement ◽  
Robust Controller ◽  
State Behavior ◽  
Nonlinear Parameters ◽  
Six Degrees Of Freedom ◽  
Aerial Vehicle

In this article, a new and novel robust hybrid control algorithm is designed for tuning the parameters of unmanned aerial vehicle (UAV). The quadrotor type UAV mathematical model is taken to observe the effectiveness of our designed robust hybrid control algorithm. The robust hybrid control algorithm consists of H∞ based regulation, pole-placement and tracking (RST) controller along with mixed sensitivity function is applied to control the complete model of UAV. The selected rotor craft is under-actuated, nonlinear and multivariable behavior in nature along with six degrees of freedom (DOF). Due to all these aforementioned issues its stabilization is quite difficult as compared to fully actuated systems. For the tuning of nonlinear parameters of the UAV, we designed, robust hybrid control algorithm is used. Moreover, the performance of the designed controller is compared with robust controller. The validity and effectiveness of the designed controllers are simulated in MATLAB and Simulink, in which the designed controller shows better steady state behavior, robustness and converges quickly in specific amount of time as compared to robust controller.

Use of Spine Robot Employing Real Time Force Control to Simulate a Pure Moment Protocol for the Subaxial Cervical Spine: An In Vitro Biomechancial Study

2011 ◽  
Author(s):  
Daniel M. Wido ◽  
Denis J. DiAngelo ◽  
Brian P. Kelly
Keyword(s):  
Cervical Spine ◽  
Real Time ◽  
Force Control ◽  
Biomechanical Testing ◽  
Subaxial Cervical Spine ◽  
Experimental Artifact ◽  
Pure Moment ◽  
Robotic Testing ◽  
Spine Robot

A standard biomechanical testing protocol for evaluation of the sub-axial cervical spine is the application of pure bending moments to the free end of the spine (with opposing end fixed) and measurement of its motion response. The pure moment protocol is often used to compare spinal fusion instrumentation and has also been used to evaluate non-fusion instrumentation (e.g. disc arthroplasty devices) [1,2]. A variety of different testing systems have been employed to implement pure moment application. In cases where the loading is applied quasi-statically using a series of weights and pulleys the spine may relax between intermittent loading phases and/or unintended loading may be applied causing experimental artifact. Our objective was to use an existing programmable robotic testing platform (Spine Robot) to develop a novel real time force control strategy to simulate pure moment loading under precisely controlled continuous movement conditions. This would serve to advance robotic testing capabilities with an end goal to simulate different protocols in the same platform, and to potentially minimize fixturing and quasi-static artifacts.

scholarly journals Validation of a Redundant Robotic Manipulator for Shoulder in Vitro Biomechanical Testing.

2021 ◽  
Author(s):  
Florent Moissenet ◽  
Clément Rastoll ◽  
David Gonzalez ◽  
Noria Foukia ◽  
Michel Lauria ◽  
...  
Keyword(s):  
Medical Devices ◽  
Degrees Of Freedom ◽  
Biomechanical Testing ◽  
Kinematic Chain ◽  
Shoulder Girdle ◽  
Robotic Manipulator ◽  
Joint Function ◽  
Universal Testing ◽  
Diarthrodial Joint

Abstract Cadaveric joint simulators are commonly used to explore native and pathological joint function as well as to test medical devices. Recently, robotic manipulators have been proposed as a new gold standard for in vitro biomechanical testing as they offer higher possibilities than Universal Testing Machines in terms of degrees of freedom (DOF). However, current protocols remain conducted in extra-corporal conditions by fixing one segment of a diarthrodial joint while mobilising the other segment. Moreover, induced motions are commonly not specimen-specific and do not respect related joint kinematic constraints and physiologic boundaries. In this study, using a 7 DOF redundant robotic manipulator, an intra-corporal condition protocol was defined. This protocol allows 1) the analysis of the shoulder girdle full kinematic chain, 2) the replication of specimen-specific humerus motions initially induced by an operator. On the 10 shoulders tested, the robotic manipulator was able to perform requested end-effector motions with a reliability of 0.28 ± 0.57 mm and 0.15 ± 0.25°, and a fidelity of 0.27 ± 0.56 mm and 0.22 ± 0.28°. This protocol will be used in the future to explore joint function as well as to test medical devices, on the shoulder girdle and potentially other joints.

Modeling and Controlling the Dynamic Behavior of an Aerial Manipulator

2021 ◽  
pp. 2150044
Author(s):  
Zain Anwar Ali ◽  
Li Xinde
Keyword(s):  
Dynamic Behavior ◽  
Control Algorithm ◽  
Degrees Of Freedom ◽  
Control Mechanism ◽  
Hybrid Control ◽  
External Noise ◽  
Pole Placement ◽  
Aerial Manipulator ◽  
Aerial Vehicle ◽  
Model Reference Adaptive

Unmanned Aerial Vehicles (UAVs) installed with a gripper is an effective and robust way to grab the wanted object from inaccessible locations. In this study, we develop a novel control mechanism to regulate the nonlinear dynamics of the aerial manipulator. In this research, hex-rotor UAV is chosen in order to fulfill the mission requirement in terms of size and weight of the object. It is equipped with a manipulator and the gimbal-based camera that will help to see the desired object and then transport it. The aerial vehicle has six-degrees-of-freedom (6-DOF) and the installed manipulator has 4-DOF which in total makes the 10-DOF aerial manipulator vehicle. At the time of clutching the desired object to eliminate or reduce the external noise, and stabilize the dynamic behavior of the aerial manipulator, we need a robust and efficient controller. To solve the aforementioned problems, this study develops a hybrid control mechanism that tracks and controls the altitude and attitude of UAV after clutching the desired object. The main contribution of this study is to design a control mechanism that includes Model Reference Adaptive Control with an Integrator (MRACI) in conjunction with regulation, pole-placement and tracking (RST) control algorithm. On one hand, the simulation results using MATLAB demonstrate the efficiency of the proposed control mechanism. On the other hand, to cross verify the validity of the proposed control algorithm, we perform the experiment by clutching the desired object at hovering and normal flight operation.

scholarly journals A Reconfigurable Multiplanar In Vitro Simulator for Real-Time Absolute Motion With External and Musculotendon Forces

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Joshua T. Green ◽  
Rena F. Hale ◽  
Jerome Hausselle ◽  
Roger V. Gonzalez
Keyword(s):  
Real Time ◽  
Degrees Of Freedom ◽  
Hybrid Control ◽  
Dynamic Control ◽  
El Paso ◽  
University Of Texas ◽  
Absolute Motion ◽  
Joint Load ◽  
Accuracy And Repeatability

Advancements in computational musculoskeletal biomechanics are constrained by a lack of experimental measurement under real-time physiological loading conditions. This paper presents the design, configuration, capabilities, accuracy, and repeatability of The University of Texas at El Paso Joint Load Simulator (UTJLS) by testing four cadaver knee specimens with 47 real-time tests including heel and toe squat maneuvers with and without musculotendon forces. The UTJLS is a musculoskeletal simulator consisting of two robotic manipulators and eight musculotendon actuators. Sensors include eight tension load cells, two force/torque systems, nine absolute encoders, and eight incremental encoders. A custom control system determines command output for position, force, and hybrid control and collects data at 2000 Hz. Controller configuration performed forward-dynamic control for all knee degrees-of-freedom (DOFs) except knee flexion. Actuator placement and specimen potting techniques uniquely replicate muscle paths. Accuracy and repeatability standard deviations across specimen during squat simulations were equal or less than 8 N and 5 N for musculotendon actuators, 30 N and 13 N for ground reaction forces (GRFs), and 4.4 N·m and 1.9 N·m for ground reaction moments. The UTJLS is the first of its design type. Controller flexibility and physical design support axis constraints to match traditional testing rigs, absolute motion, and synchronous real-time simulation of multiplanar kinematics, GRFs, and musculotendon forces. System DOFs, range of motion, and speed support future testing of faster maneuvers, various joints, and kinetic chains of two connected joints.

scholarly journals An improved biomechanical testing protocol for evaluating spinal arthroplasty and motion preservation devices in a multilevel human cadaveric cervical model

2004 ◽  
Vol 17 (3) ◽  
pp. 1-29 ◽  
Author(s):  
Denis J. DiAngelo ◽  
Kevin T. Foley
Keyword(s):  
Cervical Spine ◽  
Biomechanical Testing ◽  
Bending Moment ◽  
Testing Methods ◽  
Motion Response ◽  
Testing Protocol ◽  
Spinal Arthroplasty ◽  
Pure Moment ◽  
The Individual

Object An experimental study was performed to determine the biomechanical end-mounting configurations that replicate in vivo physiological motion of the cervical spine in a multiple-level human cadaveric model. The vertebral motion response for the modified testing protocol was compared to in vivo motion data and traditional pure-moment testing methods. Methods Biomechanical tests were performed on fresh human cadaveric cervical spines (C2–T1) mounted in a programmable testing apparatus. Three different end-mounting conditions were studied: pinned–pinned, pinned–fixed, and translational/pinned–fixed. The motion response of the individual segmental vertebral rotations was statistically compared using one-way analysis of variance and Student-Newman-Keuls tests (p < 0.05 unless otherwise stated) to determine differences in the motion responses for different testing methods. Conclusions A translational/pinned–fixed mounting configuration induced a bending-moment distribution across the cervical spine, resulting in a motion response that closely matched the in vivo case. In contrast, application of pure-moment loading did not reproduce the physiological response and is less suitable for studying disc arthroplasty and nonfusion devices.

scholarly journals Lumbar Interbody Fusion Conducted on a Porcine Model with a Bioresorbable Ceramic/Biopolymer Hybrid Implant Enriched with Hyperstable Fibroblast Growth Factor 2

Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 733
Author(s):  
Milan Krticka ◽  
Ladislav Planka ◽  
Lucy Vojtova ◽  
Vladimir Nekuda ◽  
Premysl Stastny ◽  
...  
Keyword(s):  
Growth Factor ◽  
Lumbar Fusion ◽  
Biomechanical Testing ◽  
Fibroblast Growth Factor 2 ◽  
Oxidized Cellulose ◽  
Fibroblast Growth ◽  
Micro Ct ◽  
Bone Autograft ◽  
Autograft Group

Many growth factors have been studied as additives accelerating lumbar fusion rates in different animal models. However, their low hydrolytic and thermal stability both in vitro and in vivo limits their workability and use. In the proposed work, a stabilized vasculogenic and prohealing fibroblast growth factor-2 (FGF2-STAB®) exhibiting a functional half-life in vitro at 37 °C more than 20 days was applied for lumbar fusion in combination with a bioresorbable scaffold on porcine models. An experimental animal study was designed to investigate the intervertebral fusion efficiency and safety of a bioresorbable ceramic/biopolymer hybrid implant enriched with FGF2-STAB® in comparison with a tricortical bone autograft used as a gold standard. Twenty-four experimental pigs underwent L2/3 discectomy with implantation of either the tricortical iliac crest bone autograft or the bioresorbable hybrid implant (BHI) followed by lateral intervertebral fixation. The quality of spinal fusion was assessed by micro-computed tomography (micro-CT), biomechanical testing, and histological examination at both 8 and 16 weeks after the surgery. While 8 weeks after implantation, micro-CT analysis demonstrated similar fusion quality in both groups, in contrast, spines with BHI involving inorganic hydroxyapatite and tricalcium phosphate along with organic collagen, oxidized cellulose, and FGF2- STAB® showed a significant increase in a fusion quality in comparison to the autograft group 16 weeks post-surgery (p = 0.023). Biomechanical testing revealed significantly higher stiffness of spines treated with the bioresorbable hybrid implant group compared to the autograft group (p < 0.05). Whilst histomorphological evaluation showed significant progression of new bone formation in the BHI group besides non-union and fibrocartilage tissue formed in the autograft group. Significant osteoinductive effects of BHI based on bioceramics, collagen, oxidized cellulose, and FGF2-STAB® could improve outcomes in spinal fusion surgery and bone tissue regeneration.

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