Vahid Aminzadeh

A novel tumor localization method using haptic palpation based on soft tissue probing data.

Current surgical tele-manipulators do not provide explicit haptic feedback during soft tissue palpation. Haptic information could improve the clinical outcomes significantly and help to detect hard inclusions within soft-tissue organs indicating potential abnormalities. However, system instability is often caught by direct force feedback. In this paper, a new approach to intra-operative tumor localization is introduced. A virtual-environment tissue model is created based on the reconstructed surface of a soft-tissue organ using a Kinect depth sensor and the organs stiffness distribution acquired during rolling indentation measurements. Palpation applied to this tissue model is haptically fed back to the user. In contrast to previous work, our method avoids the control issues inherent to systems that provide direct force feedback. We demonstrate the feasibility of this method by evaluating the performance of our tumor localization method on a soft tissue phantom containing buried stiff nodules. Results show that participants can identify the embedded tumors; the proposed method performed nearly as well as manual palpation.

Kinematic Analysis and Stiffness Validation of Origami Cartons

Origami-type cartons have been widely used in packaging industry because of their versatility, but there is a lack of systematic approach to study their folding behavior, which is a key issue in designing packaging machines in packaging industry. This paper addresses the fundamental issue by taking the geometric design and material property into consideration, and develops mathematical models to predict the folding characteristics of origami cartons. Three representative types of cartons, including tray cartons, gable cartons, and crash-lock cartons were selected, and the static equilibrium of folding process was developed based on their kinematic models in the frame work of screw theory. Subsequently, folding experiments of both single crease and origami carton samples were conducted. Mathematical models of carton folding were obtained by aggregating single creases folding characteristics into the static equilibrium, and they showed good agreements with experiment results. Furthermore, the mathematical models were validated with folding experiments of one complete food packaging carton, which shows the overall approach has potential value in predicting cartons folding behavior with different material properties and geometric designs.

Force-velocity modulation strategies for soft tissue examination

Advanced tactile tools in minimally invasive surgery have become a pressing need in order to reduce time and improve accuracy in localizing potential tissue abnormalities. In this regard, one of the main challenges is to be able to estimate tissue parameters in real time. In palpation, tactile information felt at a given location is identified by the viscoelastic dynamics of the neighboring tissue. Due to this reason the tissue examination behavior and the distribution of viscoelastic parameters in tissue should be considered in conjunction. This paper investigates the salient features of palpation behavior on soft tissue determining the effectiveness of localizing hard nodules. Experimental studies involving human participants, and validation tests using finite element simulations and a tele-manipulator, were carried out. Two distinctive tissue examination strategies in force-velocity modulation for the given properties of target tissue were found. Experimental results suggest that force-velocity modulations during continuous path measurements are playing an important role in the process of mechanical soft tissue examination. These behavioral insights, validated by detailed numerical models and robotic experimentations shed light on future designs of optimal robotic palpation.

Structure Design, Kinematics and Grasp Constraint of a Metamorphic Robotic Hand for Meat Deboning Operation

A four-fingered metamorphic robotic hand with a reconfigurable palm is presented in this paper with the application in deboning operation of meat industry. This robotic hand has a reconfigurable palm that generates changeable topology and augments dexterity and versatility for the hand. Mechanical structure and design of the robotic hand are presented and based on mechanism decomposition, kinematics of the metamorphic hand is investigated with closed-form solutions leading to the workspace characterization of the robotic hand. Based on the kinematics of the four-fingered metamorphic hand, utilizing product-of-exponentials formula, grasp map and grasp constraint of the hand are then formulated revealing the grasp robustness and manipulability performed by the metamorphic hand. A prototype of the four-fingered metamorphic hand is consequently fabricated and integrated with low level control and sensor systems leading to a scenario of applying the hand in the field of meat industry for deboning operation.© 2013 ASME

Friction Compensation and Control Strategy for the Dexterous Robotic Hands

Friction in tendon based robot hands has been an unavoidable problem. With introduction of more dexterous and metamorphic hands this intrinsically non-linear and highly time-varying force has become an obstacle to achieve high performances and required accuracy which the robot designers are aiming for. This paper proposes a method to tackle the problem by measuring friction and applying it in a feed forward loop. The novelty of the method is in the possibility to perform the task automatically and on a regular basis to compensate the time varying phenomenon.

Prehension analysis and manipulability of an anthropomorphic metamorphic hand with a reconfigurable palm

This paper presents a novel anthropomorphic metamorphic hand with a reconfigurable palm. Structure of the metamorphic hand is briefly introduced, followed by prehension analysis based on the opposition-space model. Manipulability of the hand is then studied combining the characteristic matrix equation and singular value decomposition, leading to the explicit symbolic closed-form solutions. Further, the prototype of the robotic hand is developed integrated with the initial control system, and grasping and manipulation tests are carried out to illustrate dexterity and characteristic of the new metamorphic hand.

A new algorithm for pick-and-place operation

Purpose – This paper aims to represent a novel framework for optimization of robotic handling from disarray to structure where the products are randomly distributed on a surface, the initial location of the products are known (with the aid of image processing, laser position sensors, etc.) and there is a set of final positions for the products.Design/methodology/approach – Pick‐and‐place is one of the main solutions especially for the food products where the products are prone to damage, have adhesive surfaces and the grippers can be complicated. The aim of this paper is to maximize the utilization of the pick‐and‐place robotic system. In order to do so the handling process is modelled mathematically and the pick‐and‐place problem is formulated based on assignment problem where Hungarian algorithm is utilized to minimize the total distance travelled by the robot. Furthermore, a simulation program is developed to demonstrate the possible improvements of the algorithm in comparison with the existing algorit...

Introducing a new 3D ordering process for discrete food products using food categorisation

Purpose – This paper aims to introduce and identify a new 3D handling operation (bin picking) for natural discrete food products using food categorisation.Design/methodology/approach – The research shows a new food categorisation and the relation between food ordering processes and food categories. Bin picking in the food industry needs more flexible vision software compared to the manufacturing industry in order to decrease the degree of disarray of food products and transfer them into structure.Findings – It has been shown that there are still manual operated ordering processes in food industry such as bin picking; it just needs new ideas of image processing algorithms such as active shape models (ASMs) on its development in order to recognise the highly varying shapes of food products.Research limitations/implications – This research was aimed at locating a new ordering process and proving a new principle, but for practical implementation this bin picking solution needs to be developed and tested furth...

Evaluating Manual Palpation Trajectory Patterns in Tele-manipulation for Soft Tissue Examination

Robot-assisted minimal invasive surgery made it possible to improve the quality of surgical procedures and to enhance clinical outcomes. However, the need to palpate soft tissue organs with the aim to localize potential sites of abnormalities in real time has been recognized. For this work, ten subjects were recruited to perform a remote palpation procedure on a silicone phantom utilizing a tele-manipulation setup, to study their behavior when remotely palpating soft tissue. The stiffness values acquired during the remote palpation of a silicone phantom were transferred to the subjects by means of haptic and visual feedback. Participating subjects were asked to detect hard nodules in the silicone tissue using two distinct strategies: a) randomly chosen movements, and b) trajectory pattern, based on manual palpation techniques for clinical breast examination. We have compared relevant parameters, defining patterns observed during manual palpation, with the counterpart patterns occurring during remote palpation. The results show the effectiveness of applying palpation trajectory pattern used during manual soft tissue examination to tele-manipulation palpation.

Kinematic and Stiffness Analysis of an Origami-Type Carton

This paper investigates the stiffness characteristics of an origami-type carton, which can be modeled into an equivalent mechanism by considering creases as revolute joints and panels as links. Stiffness characteristics of a single crease is investigated regarding its relationships with folding angular velocity and crease length. Based on the kinematic analysis of carton folding, the aggregated stiffness is obtained by integrating the individual crease stiffness into the equivalent mechanism. Finally experiment results of carton folding manipulation are obtained, and comparisons between the mathematical model and experimental data show that the model predicts the carton’s behaviour well.Copyright