An Adapting Mechanism to Manipulate Manual Wristed Laparoscopic Instruments by a Robotic Surgery System

Abstract

Abstract-Sina is a robotic telesurgery system that accepts and works with conventional laparoscopic tools at its endeffector. This paper describes the design and analysis of an adapting mechanism for Sina, to enable manipulating a manual wristed laparoscopic instrument, i.e., Laparo-Angle by the system. After identification of the kinematics and dynamics characteristics of Laparo-Angle experimentally, .the design considerations of the adapting mechanism, including compatibility with the instrument (at one side) and the host robotic arm (at the other side), required kinematics and dynamics features, ease of tool replacement, etc., were studied and a conceptual design, based on the Agile Eye mechanism, was proposed. The forward and inverse kinematics analysis of the proposed mechanism revealed that it is capable of providing the desired workspace while meeting the design constraints. The workspace of the mechanism was a cone with an apex angle of 35 degrees, in which both the isotropy and manipulability indices were satisfying. The condition number and the Jacobean determinant of the mechanism within its workspace were lower than 1.4 and higher than 1, respectively. In general, the proposed mechanism was found to could satisfy the design requirements and constrains.

A modified agile-eye mechanism for robotic manipulation of wristed laparoscopic instruments

“…The condition number was lower than 1.31 and the determinant of the Jacobian ranged between 0.7 to 1.71 in the target workspace. Table 1 compares the structure and the performance measures of the non-symmetric agile-eye mechanism designed in this study with those of the orthogonal agile-eye, proposed in a previous investigation [3]. The link lengths λ, γ, and ξ decreased from 90 • in [3] to 64 • , 69 • , 35 • , respectively, in the current study, which indicates a considerable size reduction.…”

“…Table 1 compares the structure and the performance measures of the non-symmetric agile-eye mechanism designed in this study with those of the orthogonal agile-eye, proposed in a previous investigation [3]. The link lengths λ, γ, and ξ decreased from 90 • in [3] to 64 • , 69 • , 35 • , respectively, in the current study, which indicates a considerable size reduction. Also, the maximum condition number reduced from 2.71 to 1.31, which corresponds to improvement in isotropy.…”

“…A simple orthogonal 5R-SPM, i.e. Agile Eye [23], however, has been shown to be incapable of meeting the collision free design requirement of the manipulator [3]. Hence, this study investigated the performance of a new nonsymmetric structure of 5R-SPM, with orthogonal links in one chain and links with arbitrary lengths in the other [24], for this application (Fig.…”

“…An alternative solution to make the surgical instruments less costly and single-use, is to enable the surgical robot to work with commercial hand-held wristed laparoscopic instruments [3], [4]. There are several models of such instruments available in the market and used in clinical practice, e.g., RealHand (Novare Surgical Systems, Inc.) [5], Autonomy Laparo-Angle Articulating Instruments (Cambridge Endoscopic Devices, Inc.) [6], and SILS Hand Instruments (Medtronic-Covidien) [7], [8], [9].…”

“…The parallel RCM mechanisms, e.g., spherical parallel mechanism (SPM), gimbal mechanism, and parallel wrist mechanism, have been also suggested for MIRS application considering their high rigidity to size ratio and low moving inertia [14]. Among different variations of parallel RCM mechanisms, SPMs are most attractive for their compact structure, great manipulability and low moving inertia [15], [16], [17] and have been proposed for various surgical applications such as camera holding [18], bone flap removal [19], laparoscopic surgery [3], [20], teleechography [21] and others [22].…”