Pneumoperitoneum simulation based on mass-spring-damper models for laparoscopic surgical planning

Abstract

Abstract. Laparoscopic surgery, which is one minimally invasive surgical technique that is now widely performed, is done by making a working space (pneumoperitoneum) by infusing carbon dioxide (CO 2 ) gas into the abdominal cavity. A virtual pneumoperitoneum method that simulates the abdominal wall and viscera motion by the pneumoperitoneum based on mass-spring-damper models (MSDMs) with mechanical properties is proposed. Our proposed method simulates the pneumoperitoneum based on MSDMs and Newton's equations of motion. The parameters of MSDMs are determined by the anatomical knowledge of the mechanical properties of human tissues. Virtual CO 2 gas pressure is applied to the boundary surface of the abdominal cavity. The abdominal shapes after creation of the pneumoperitoneum are computed by solving the equations of motion. The mean position errors of our proposed method using 10 mmHg virtual gas pressure were 26.9 AE 5.9 mm, and the position error of the previous method proposed by Kitasaka et al. was 35.6 mm. The differences in the errors were statistically significant (p < 0.001, Student's t -test). The position error of the proposed method was reduced from 26.9 AE 5.9 to 23.4 AE 4.5 mm using 30 mmHg virtual gas pressure. The proposed method simulated abdominal wall motion by infused gas pressure and generated deformed volumetric images from a preoperative volumetric image. Our method predicted abdominal wall deformation by just giving the CO 2 gas pressure and the tissue properties. Measurement of the visceral displacement will be required to validate the visceral motion.

Silhouette-based pose estimation for deformable organs application to surgical augmented reality

“…For laparoscopy, D corresponds to the simulation of the pneumoperitoneum which represents the main source of shape variation. A strong assumption of our work is therefore to be able to simulate the main deformation of the organ compared to the segmented model S. We won't detail this aspect in this paper, instead we refer interested readers to the large number of publications on this topic [19], [1], [15], [10], [5].…”

“…This is mainly used to optimize the trocar's placement, rather than solving a registration problem. In a similar way, a deformed mesh is computed using a mass-springdamper model [15] as a result of pressure insulation, which is applied to the volume as boundary conditions. Recently, a database-based approach was proposed to simulate organs deformation under pneumoperitoneum [10].…”

Subject-specific modelling of pneumoperitoneum: model implementation, validation and human feasibility assessment

“…In laparoscopic procedures, the abdominal cavity is inflated with to a pressure between typically 10 and 16 mmHg, creating pneumoperitoneum. This insufflation induced between the internal organs and abdominal wall provides a workspace which allows triangulation of surgical instruments and the surgical viewpoint entry necessary to perform the procedure safely [ 1 ]. Laparoscopy is a complicated procedure, and significant research has been performed to assist the surgeon in the fields of intraoperative navigation and surgical planning.…”

“…By measuring the landmarks’ displacements and using them to feed an optimisation of the simulation parameters, the authors achieved improved accuracy when compared to the previous experience. More recently, the same group had developed a mass–spring system (MSS) approach to estimate the geometry of pneumoperitoneum [ 1 ]. The method required as input a given pressure, known mechanical properties and tomographic data.…”

Preoperative liver registration for augmented monocular laparoscopy using backward–forward biomechanical simulation

“…From a gravity compensation viewpoint, all existing methods using a biomechanical model for registration in laparoscopy ignore the gravity load and use the biomechanical model reconstructed from a segmented preoperative CT as an undeformed and stressless reference model. Because this model is in fact gravity-loaded, running a laparoscopic pneumoperitoneum simulation with it as the reference model [5][6][7][8] generates inaccuracies. Only [9] compensates for the gravity load by reversing its direction before applying laparoscopic pneumoperitoneum simulation for surgical planning purposes.…”