Development of organ stiffness models for haptic feedback in laparoscopic surgery simulation

Laparoscopic surgery is the most common Minimally Invasive Surgery (MIS) performed routinely for certain procedures such as appendectomy and Cholecystectomy. Laparoscopic surgical procedures are very complex compared to open surgeries and require a higher level of experience and expertise. A comprehensive training session on surgical simulator handling for trainee surgeons is highly recommended before the hands-on training in a real surgery. Comprehensive surgery simulators such as physical phantoms which are available for training are expensive and not readily available in many health care centers around the world. VR simulators have a great potential to revalorize the training paradigm of surgical interns. The haptic feedback plays as equally as visual feedback to provide a realistic environment to trainees. Realistic organ-force model is a key requirement of a VR simulator to experience real-time tool-tissue interaction forces. However, modeling real tissue properties has not been achieved due to several limitations such as the inaccessibility to in-vivo tissue properties, the complex behavior of biological tissues and anatomical variability. We have adopted an alternative approach to incorporate force feedback to VR simulators. The abdomen organ models (liver, gallbladder, stomach, bone, and vessel) were generated using the color Cryosection dataset of the Visible Human Project. A novel method was applied to render forces by fine-tuning the stiffness of organ model and integrating the three force ranges: soft, mild/firm and hard into organ models using feedback received from expert surgeons. The proposed system provides the interaction forces through a haptic device with six Degrees of Freedom (DoF) position sensing and three DOF force feedback. The simulated organ models were evaluated by two experienced surgeons. The proposed haptic models were mostly in harmony with their experience in real-world tool-tissue interaction and the overall accuracy of identifying the correct organ property was more than 68%. The organ models were also tested with senior registrars. The results showed a considerable improvement amounting to more than 34% chances of selecting the correct organ property after training

Development of organ stiffness models for haptic feedback in laparoscopic surgery simulation

Laparoscopic surgery is the most common Minimally Invasive Surgery (MIS) performed routinely for certain procedures such as appendectomy and Cholecystectomy. Laparoscopic surgical procedures are very complex compared to open surgeries and require a higher level of experience and expertise. A comprehensive training session on surgical simulator handling for trainee surgeons is highly recommended before the hands-on training in a real surgery. Comprehensive surgery simulators such as physical phantoms which are available for training are expensive and not readily available in many health care centers around the world. VR simulators have a great potential to revalorize the training paradigm of surgical interns. The haptic feedback piays as equally as visual feedback to provide a realistic environment to trainees. Realistic organ-force model is a key requirement of a VR simulator to experience real-time tool-tissue interaction forces. However, modeling real tissue properties has not been achieved due to several limitations such as the inaccessibility to invivo tissue properties, the complex behavior ofbiological tissues and anatomical variability. We have adopted an alternative approach to incorporate force feedback to VR simulators. The abdomen organ models (liver, gallbladder, stomach, bone, and vessel) were generated using the color Cryosection dataset of the Visible Human Project. A novel method was applied to render forces by fine-tuning the stiffness of organ modei and integrating the three force ranges: soft, mild/firm and hard into organ models using feedback received from expert surgeons. The proposed system provides the interaction forces through a haptic device with six Degrees of Freedom (DoF) position sensing and three DOF force feedback. The simulated organ models were evaluated by two experienced surgeons. The proposed haptic models were mostly in harmony with their experience in real-world tool-tissue interaction and the overall accuracy of identifying the correct organ property was more than 68%. The organ models were also tested with senior registrars. The results showed a considerable improvement amounting to more than 34% chances of selecting the correct organ property after training

Simulating haptic feedback of abdomen organs on Laparoscopic Surgery Tools

Minimally invasive surgeries (MIS) such as laparoscopic procedures are widely used for many types of abdomen surgeries because of its numerous advantages over open surgeries. They require very high level of skills of surgeons acquired through experience. The best and the safest way of getting hands on experience is the computer simulation or virtual reality (VR). The VR surgical simulators have a great potential to revolutionize the training paradigm of surgical interns. The haptic feedback plays as equally asvisual feedback to provide realistic environment to trainees. In this paper, we present a method incorporate hapitics on VR simulator. A software procedure is developed using the Libraries of Open Haptic Toolkit along with the Open GL graphic libraries to implement three basic haptic ranges: soft, mild(firm) and hard into organ models. The feedback of the expert surgeons in the field was obtained to model the organs rather than measuring mechanical properties of soft tissues due to practical limitations. A commercially available six Degrees of Freedom (DoF) position sensing and three DoF force feedback haptic devices are used to implement the interface

Hardware interface for haptic feedback in laparoscopic surgery simulators

Minimally Invasive Surgeries (MIS) such as laparoscopic procedures are increasingly preferred over conventional surgeries due to many different advantages. Laparoscopic surgical procedures are very complex compared to open surgeries and require high level of experience and expertise. Hybrid surgery simulators available for training using physical phantoms are expensive and not readily available in majority of health care facilities around the world. Therefore, computer simulation or Virtual Reality (VR) is a better way to obtain skills for MIS. A VR simulator incorporated with haptic feedback provides a comprehensive training closer to real world experience. In this paper, we present a novel approach to incorporate force feedback to VR laparoscopic surgery training. The proposed interface incorporates force feedback in all three axes to provide three levels of force feedback. Computational models of abdomen organs were generated using the cryosection data of Visible Human Project of the National Library of Medicine, USA. The organ models were developed with three basic force categories: soft, mild and hard. A hardware interface is developed to provide the force feedback for the interaction of virtual tools with the said organ models while generating the tool navigation information for the VR simulator