Haptics Haptics Haptic : Haptic : Haptic and Tactile Feedback - PDF document

Haptics Haptics � Haptic : Haptic : Haptic and Tactile Feedback Haptic and Tactile Feedback � Relating to or based on the sense of touch. Relating to or based on the sense of touch. Force feedback Haptic feedback M. Cenk Cavusoglu, PhD M. Cenk Cavusoglu, PhD Tactile feedback cavusoglu@case.edu cavusoglu@case.edu • Surgical simulation as haptic interaction Case Western Reserve University Case Western Reserve University Dept. of Electrical Eng. and Computer Sci Dept. of Electrical Eng. and Computer Sci. . with virtual surgical environments http://vorlon.cwru.edu/~mcc14/ http://vorlon.cwru.edu/~mcc14/ http://simcen.usuhs.mil/miccai2003 http://simcen.usuhs.mil/miccai2003 Simulation for Medical Training – MICCAI 2003 Research Issues in Haptic Research Issues in Haptic Force Feedback Haptic Devices Force Feedback Haptic Devices Interfacing to Virtual Environments Interfacing to Virtual Environments � Haptic interface devices Haptic interface devices Commercial Systems: Commercial Systems: � � Stability of haptic interaction with virtual Stability of haptic interaction with virtual � Phantom Phantom � � environments environments – 3 DOF and 6 DOF versions 3 DOF and 6 DOF versions – � Immersion Immersion � Simulation of stiff walls Simulation of stiff walls � � – Impulse Engine – Impulse Engine � Haptic rendering of surface texture Haptic rendering of surface texture � – CathSim – CathSim AccuTouch AccuTouch � Haptic interaction with deformable bodies Haptic interaction with deformable bodies � » Endovascular Endovascular » � Realistic modeling of tool Realistic modeling of tool- -tissue interaction tissue interaction » Bronchoscopy » Bronchoscopy � – Laparoscopic Interface – Laparoscopic Interface – – Cutting, suturing, needle insertion Cutting, suturing, needle insertion � Freedom 6S Freedom 6S � � Tactile sensing and display Tactile sensing and display � – 6 DOF force feedback – 6 DOF force feedback Simulation for Medical Training – MICCAI 2003 Simulation for Medical Training – MICCAI 2003 Haptic Interaction with Haptic Interaction with Deformable Bodies in VE’s VE’s Deformable Bodies in � Deformable bodies are simulated with very high Deformable bodies are simulated with very high � order dynamical models order dynamical models Generation of Force Feedback Generation of Force Feedback � Haptic interaction require bandwidth of ~1kHz, Haptic interaction require bandwidth of ~1kHz, � but these high order models can only be simulated but these high order models can only be simulated at ~10Hz at ~10Hz � This affects the stability and fidelity of interaction This affects the stability and fidelity of interaction � Simulation for Medical Training – MICCAI 2003 Simulation for Medical Training – MICCAI 2003

Simulation Schemes Simulation Schemes Demonstration of the Problem Demonstration of the Problem � Interaction with a Interaction with a � x nonlinear spring in nonlinear spring in F one dimension one dimension – 10 Hz model update – 10 Hz model update F – 1 kHz haptic update – 1 kHz haptic update x Simulation for Medical Training – MICCAI 2003 Simulation for Medical Training – MICCAI 2003 Low Order Linear Approximation Low Order Linear Approximation Demonstration of the Problem Demonstration of the Problem to Model Intersample Intersample Behavior Behavior to Model Simulation for Medical Training – MICCAI 2003 Simulation for Medical Training – MICCAI 2003 Model Reduction Model Reduction Model Reduction Model Reduction � 12x12 2 12x12 2- -D lumped D lumped � element model element model – – 2 input 2 output 2 input 2 output dynamical system dynamical system th order dynamics – – 524 524 th order dynamics � Balanced model Balanced model � reduction reduction th order approximation – 10 10 th order approximation – with less than 1% error with less than 1% error Simulation for Medical Training – MICCAI 2003 Simulation for Medical Training – MICCAI 2003

Reduced Order Model Is a Local Reduced Order Model Is a Local Constructing a Local Model in Constructing a Local Model in Approximation Approximation Real Time Real Time Simulation for Medical Training – MICCAI 2003 Simulation for Medical Training – MICCAI 2003 Constructing a Local Model in Constructing a Local Model in Implementation Implementation Real Time Real Time � 6x6x6 3 6x6x6 3- -D model D model � � Simulation run on a Simulation run on a � dual processor SGI dual processor SGI octane octane � C++, OpenGL C++, OpenGL � TM v1.5 as � Phantom Phantom TM v1.5 as � the haptic interface the haptic interface � 20 Hz model update 20 Hz model update � � 1 kHz haptic update 1 kHz haptic update � Simulation for Medical Training – MICCAI 2003 Simulation for Medical Training – MICCAI 2003 Stability Implications Stability Implications Discussion Discussion � Update rate of Update rate of � simulation is a simulation is a � This method is applicable only if the local This method is applicable only if the local � critical factor for critical factor for modes are dominant. modes are dominant. stability of stability of interaction. interaction. � Interaction stability is improved Interaction stability is improved � � 1 kHz haptic 1 kHz haptic � significantly. significantly. simulation instead of simulation instead of 10 Hz improves 10 Hz improves � It is informative to study other local models. It is informative to study other local models. � stability. stability. � Oscillatory behavior Oscillatory behavior � present in low present in low frequency simulation frequency simulation is not observed. is not observed. Simulation for Medical Training – MICCAI 2003 Simulation for Medical Training – MICCAI 2003

Other Methods for Generation of Other Methods for Generation of Modeling of Needle Insertion Modeling of Needle Insertion Haptic Feedback Haptic Feedback � Constraint Constraint- -Based Methods Based Methods Coming up in the Tissue Modeling section of Coming up in the Tissue Modeling section of � (Zilles ( Zilles and Salisbury 1995) and Salisbury 1995) the tutorial ! the tutorial ! � Planar and Spherical Local Approximations Planar and Spherical Local Approximations � ( (d’Aulignac d’Aulignac et al. 2000) et al. 2000) � Norton Equivalent Models Norton Equivalent Models � (Astley Astley and Hayward 1998) and Hayward 1998) ( � Force Fields Force Fields � (Montgomery et al. 2002) (Montgomery et al. 2002) Simulation for Medical Training – MICCAI 2003 Simulation for Medical Training – MICCAI 2003 Simulated Surface Compliance Discrimination Simulated Surface Compliance Discrimination � Psychophysics literature on compliance has measured Psychophysics literature on compliance has measured � difference thresholds difference thresholds � Surgeons often need to detect spatial variation in surface Surgeons often need to detect spatial variation in surface � Human Factors for Enhanced Human Factors for Enhanced compliance, e.g. to detect embedded lesion compliance, e.g. to detect embedded lesion � Two tasks: Two tasks: � Force Feedback in MIS Force Feedback in MIS – spatial variation in compliance – spatial variation in compliance – temporal oscillation in force – temporal oscillation in force Compliance Stimuli Force Stimuli Simulation for Medical Training – MICCAI 2003 Simulation for Medical Training – MICCAI 2003 Methods Methods Compliance Discrimination and Contrast Sensitivity Compliance Discrimination and Contrast Sensitivity � Phantom 1.5 haptic interface Phantom 1.5 haptic interface � � Adaptive 2 Adaptive 2- -down 1 down 1- -up up � procedure (corresponds to procedure (corresponds to 71% accuracy) 71% accuracy) � 8 subjects 8 subjects � � 3 mean compliance levels: 3 mean compliance levels: � 2, 4, and 8 mm/N 2, 4, and 8 mm/N � 3 mean force levels: 3 mean force levels: � 0.5, 1, and 2 N 0.5, 1, and 2 N Simulation for Medical Training – MICCAI 2003 Simulation for Medical Training – MICCAI 2003 Experimental Results from Dhruv and Tendick (2000)

Tactile Sensing and Display Tactile Sensing and Display 8x8 1mm 2 Tactile Sensor Array Tactile Sensing and Display Tactile Sensing and Display Image courtesy of Gray and Fearing Simulation for Medical Training – MICCAI 2003 Simulation for Medical Training – MICCAI 2003 Human Factors in Tactile Sensing Human Factors in Tactile Sensing Tactile Display Technology Tactile Display Technology and Display and Display � Do we need a tactile display capable of displaying shear Do we need a tactile display capable of displaying shear � stress ? stress ? Simulation for Medical Training – MICCAI 2003 Images courtesy of Fearing et al. Simulation for Medical Training – MICCAI 2003 Experimental results from Moy and Fearing (1998) Tactile Feedback Tactile Feedback Tactile Feedback Tactile Feedback � DC servomotor based DC servomotor based � SMA based tactile SMA based tactile � � display display tactile display tactile display � Vibrotactile Vibrotactile Feedback Feedback � Simulation for Medical Training – MICCAI 2003 Images courtesy of Howe et al. Simulation for Medical Training – MICCAI 2003 Images courtesy of Howe et al.