Haptic pulse simulation for virtual palpation

Frontiers in Robotics and AI, 2022

This paper explores methods that make use of visual cues aimed at generating actual haptic sensation to the user, namely pseudo-haptics. We propose a new pseudo-haptic feedback-based method capable of conveying 3D haptic information and combining visual haptics with force feedback to enhance the user’s haptic experience. We focused on an application related to tumor identification during palpation and evaluated the proposed method in an experimental study where users interacted with a haptic device and graphical interface while exploring a virtual model of soft tissue, which represented stiffness distribution of a silicone phantom tissue with embedded hard inclusions. The performance of hard inclusion detection using force feedback only, pseudo-haptic feedback only, and the combination of the two feedbacks was compared with the direct hand touch. The combination method and direct hand touch had no significant difference in the detection results. Compared with the force feedback alone, our method increased the sensitivity by 5 %, the positive predictive value by 4 %, and decreased detection time by 48.7 %. The proposed methodology has great potential for robot-assisted minimally invasive surgery and in all applications where remote haptic feedback is needed.

2020 American Control Conference (ACC), 2020

International journal of engineering research and technology, 2018

Haptic Interface are designed to allow humans to touch virtual objects as they were real. Unfortunately, virtual surface models currently require extensive hand tuning and do not feel authentic, which limits the usefulness and applicability of such systems. The proposed approach of Haptography seeks to address this deficiency by basing models on haptic data recorded from real interactions between a human and a target object. The studio Haptographer uses a fully instrumented stylus to tap, press and stroke an item in a controlled environment while a computer system records position, orientation, velocities, accelerations and forces. The point and touch Haptographer carries a simple instrumented Stylus around during daily life, using it to capture interesting haptic properties of items in the real world. Recorded data is distilled into Haptographer, the Haptic impressing of object or surface patch, including properties such as local shape, stiffness, friction and texture. Finally the ...

This study presents a haptic simulator for learning palpation of aorta in cardiovascular surgery and performs quantitative evaluation in educational use through some user study. The simulator implements physics-based methods that enable VR simulation of soft organs with autonomous motion like a beating heart or an aorta. The developed model simulates real-time deformation and force feedback during surgical palpation based on finite element methods. The evaluation with cardiovascular surgeons and medical students confirms the developed system is useful for learning not only surgical procedures but also stiffness of in-vivo organs.

During open surgery, surgeons can perceive the locations of tumors inside soft-tissue organs using their fingers. Palpating an organ, surgeons acquire distributed pressure (tactile) information that can be interpreted as stiffness distribution across the organan important aid in detecting buried tumors in otherwise healthy tissue. Previous research has focused on haptic systems to feedback the tactile sensation experienced during palpation to the surgeon during minimally invasive. However, the control complexity and high cost of tactile actuators limits its current application. This paper describes a pneumatic multi-fingered haptic feedback system for robotassisted minimally invasive surgery. It simulates soft tissue stiffness by changing the pressure of an air balloon and recreates the deformation of fingers as experienced during palpation. The pneumatic haptic feedback actuator is validated by using finite element analysis. The results prove that the interaction stress between the fingertip and the soft tissue as well as the deformation of fingertips during palpation can be recreated by using our pneumatic multi-fingered haptic feedback method.

Springer Tracts in Advanced Robotics

A method for real time simulation and interaction of deformable objects in medical simulators is proposed. We are interested in applications for training surgeons using haptic interaction. For haptic purposes, our medical simulator is based on a dual model architecture; simulation and haptics. We currently use a new physical model LEM-Long Element Method as the simulation model. We find that this model can produce satisfactory global changes for small and large deformations. In this paper, we will focus on implementing an haptic interaction method with stable and realistic force feedback designed for use with LEM. A deformable buffer model is used to solve problems arising from the difference between sampling and update rates. We look into the construction and the updating process of this buffer model. Our approach to linking the two models to get realistic force feedback is also presented. The physical and haptic model are then coupled to be part of a surgical simulator for soft tissue. We present some results from our prototype medical simulator for echography exams of the human thigh.

Actuators, 2022

The simulation of fabrics physics and its interaction with the human body has been largely studied in recent years to provide realistic-looking garments and wears specifically in the entertainment business. When the purpose of the simulation is to obtain scientific measures and detailed mechanical properties of the interaction, the underlying physical models should be enhanced to obtain better simulation accuracy increasing the modeling complexity and relaxing the simulation timing constraints to properly solve the set of equations under analysis. However, in the specific field of haptic interaction, the desiderata are to have both physical consistency and high frame rate to display stable and coherent stimuli as feedback to the user requiring a tradeoff between accuracy and real-time interaction. This work introduces a haptic system for the evaluation of the fabric hand of specific garments either existing or yet to be produced in a virtual reality simulation. The modeling is based...

2007

This paper presents a real-time physically based platform for multi-sensory interactive simulation. This platform is centered on high quality dynamic requirements driven by the concept of instrumental interaction. It is oriented towards the simulation of visà-vis human-object interactive simulation for a broad range of physical phenomena, with a specific focus on simulations with demanding capacities regarding dynamics such as tool use, object manipulation, music instrument playing, etc.

EuroHaptics'2008: 6th International Conference, 2008

In this paper we present an interactive dynamic simulator for virtual avatars. It allows creation and manipulation of objects in a collaborative way by virtual avatars or between virtual avatars and users. The users interact with the simulation environment using a haptic probe which provides force feedback. This dynamic simulator uses fast dynamics computation and constraint-based methods with friction. It is part of a general framework that is being devised for studies of collaborative scenarios with haptic feedback.

Signals and Systems in Biomedical Engineering: Physiological Systems Modeling and Signal Processing, 2019

That virtual reality is possible is an important fact about the fabric of reality. It is the basis not only of computation, but of human imagination and external experience, science and mathematics, art and fiction.-David Deutsch The availability of cheap computing power makes computational models available easily to physiologists. Modern computers have not only good computational capabilities but also very good graphical displays, thereby making the output of models convenient for non-mathematical users. Graphical presentation itself uses visual analogy for physical behavior. Since modern computers are all discrete numerical machines, while physiological systems are fundamentally continuous, some approximations are required in order to use discrete modeling for continuoustime systems. The issue of discretization has been dealt with in some detail in Chap. 4, and a number of digital techniques for the analysis of signals and systems have been discussed in Chap. 5. In this chapter, we look at some geometric and animation techniques for representing physiological models. We also introduce haptics which can impart a tactile component to the models. These computational models with graphical display, audio, and haptics make possible virtual experiments for physiological exploration. 6.1 Numerical Methods for Solving Equations In the early days of computational models, differential equations were solved using analog computers. The analog computers were electronic circuits whose behavior mimicked that of the system being modeled. Modern computer models use digital computers to solve the system equations. Contemporary digital computers are

Proceedings of the second international workshop on Smart material interfaces: another step to a material future - SMI '13, 2013

We present the initial exploration of using ForceForm, a dynamically deformable interactive surface, for an application in the medical domain. ForceForm provides direct dynamic interaction which is soft and malleable. We are interested in pursuing its use as a training tool in medical scenarios which involve the direct interaction with human skin. As an example of this, we have developed a palpation training application. Previous work in this area uses haptic devices which do not have the soft and direct interaction exhibited by ForceForm. This workshop paper details our palpation application and a discussion of the findings of an expert user consultation involving a doctor and a massage therapist.

Proceedings of the 1995 symposium on Interactive 3D graphics - SI3D '95, 1995

Haptic rendering is the process of computing and generating forces in response to user interactions with virtual objects. Recent efforts by our team at MIT's AI laboratory have resulted in the development of haptic interface devices and algorithms for generating the forces of interaction with virtual objects. This paper focuses on the software techniques needed to generate sensations of contact interaction and material properties. In particular, the techniques we describe are appropriate for use with the Phantom haptic interface, a force generating display device developed in our laboratory. We also briefly describe a technique for representing and rendering the feel of arbitrary polyhedral shapes and address issues related to rendering the feel of non-homogeneous materials. A number of demonstrations of simple haptic tasks which combine our rendering techniques are also described.

The work in the Touch Lab (formal name: Laboratory for Human and Machine Haptics) is guided by a broad vision of haptics which includes all aspects of information acquisition and object manipulation through touch by humans, machines, or a combination of the two; and the environments can be real or virtual. We conduct research in multiple disciplines such as skin biomechanics, tactile neuroscience, human haptic perception, robot design and control, mathematical modeling and simulation, and software engineering for real-time human-computer interactions. These scientific and technological research areas converge in the context of specific application areas such as the development of virtual reality based simulators for training surgeons, haptic aids for people who are blind, real-time haptic interactions between people across the Internet, and direct control of machines from neural signals in the brain.

ACM SIGGRAPH 2005 Courses on - SIGGRAPH '05, 2005

For a long time, human beings have dreamed of a virtual world where it is possible to interact with synthetic entities as if they were real. To date, the advances in computer graphics allow us to see virtual objects and avatars, to hear them, to move them, and to touch them. It has been shown that the ability to touch virtual objects increases the sense of presence in virtual environments .