Purpose The KneeAlign2 (KA2, OrthoAlign Inc.) accelerometer-based portable navigation system and patient-specific instrumentation (PSI; Signature, ZimmerBiomet) are widely used for ideal femoral component alignment in total knee arthroplasty (TKA). However, there has been no comparative study of the KA2 system, PSI, and conventional intramedullary instrumentation (CON). The purpose of this stud...

The object of this study was to develop a method to assess the accuracy of an image-free total knee replacement navigation system in legs with normal or abnormal mechanical axes. A phantom leg was constructed with simulated hip and knee joints and provided a means to locate the centre of the ankle joint. Additional joints located at the midshaft of the tibia and femur allowed deformation in the...

To achieve higher navigation accuracy it is necessary to align an inertial navigation system (INS) before it commences operation. With the aid of external information, in-motion alignment can improve the accuracy of the inertial navigation solution. This paper studies the in-motion alignment for the integration of Global Positioning System (GPS) and INS technologies, with a focus on the observa...

In the strap-down inertial navigation system (SINS), the initial attitude matrix is acquired through alignment. Though there were multiple valid methods, alignment time and accuracy are still core issues, especially regarding the condition of the motion carrier. Inspired by the idea of constructing nonlinear vectors by velocity in a different coordinate frame, this paper proposes an innovative ...

In this paper, we investigate the possibility of integrating a binocular stereo vision system and a laser range finder to construct 3-D map for path planning and navigation. Our proposed system is realized by forming the task as an optimization problem of minimizing the alignment error between scanned local map and selected parts of the developing global map. The problem is then solved using th...

This paper describes a new method for rapid initialization of a strapdown initial navigation system (SINS) which is hosted on a missile intended for vertical launch from a land vehicle. The SINS initialization aims to determine initial values of the system, including position, velocity, and attitude. For a fixed host platform, the attitude is the most critical aspect of the initialization. Ther...

In this paper, we present various procedures to support a ZUPT-based MEMS IMU navigation application by available external building models and photographs of evacuation plans. In detail, these are approaches for horizontal alignment of the track using the external building shell, for height correction by stair and elevator detection, for the extraction of the initial position and direction usin...

Strapdown inertial navigation systems (INS) need an alignment process to determine the initial attitude matrix between the body frame and the navigation frame. The conventional alignment process is to compute the initial attitude matrix using the gravity and Earth rotational rate measurements. However, under mooring conditions, the inertial measurement unit (IMU) employed in a ship's strapdown ...