Evaluating potential musculoskeletal disorders risks in real workstations is challenging as the environment is cluttered, which makes it difficult to accurately assess workers' postures. Being marker-free and calibration-free, Microsoft Kinect is a promising device although it may be sensitive to occlusions. We propose and evaluate a RULA ergonomic assessment in real work conditions using recen...

Freehand three-dimensional (3D) ultrasound is a technique for acquiring ultrasonic data of a 3D volume with application in radiotherapy and surgery planning. As the clinician sweeps the ultrasound probe over the anatomy, the trajectory of the probe is recorded using an attached position sensor. However, the position sensor tracks the position of the sensor, rather than the ultrasound B-scan. It...

To obtain the absolute position of a target is one of the basic topics for non-cooperated target tracking problems. In this paper, we present a simultaneously calibration method for an Inertial navigation system (INS)/Global position system (GPS)/Laser distance scanner (LDS) integrated system based target positioning approach. The INS/GPS integrated system provides the attitude and position of ...

Autonomous calibration techniques are applied to the calibration of two sensors of a planar robot: a platen sensor and a coordination sensor. The redundant angle measurements of the platen sensor are used to identify its parameters, improving its output accuracy by better than a factor of two. Redundant position measurements using both sensors are also used in an attempt to further improve the ...

We demonstrate a fast and direct calibration method for systems using a single laser for optical tweezers and particle position detection. The method takes direct advantage of back-focal-plane interferometry measuring not an absolute but a differential position, i.e. the position of the trapped particle relative to the center of the optical tweezers. Therefore, a fast step-wise motion of the op...

Digital templating with external calibration markers is the standard method for planning total hip arthroplasty. We determined the geometrical basis of the magnification effect, compared magnification with external and internal calibration markers, and examined the influence on magnification of the position of the calibration markers, patient weight, and body mass index (BMI). A formula was der...

The purpose of this study was to investigate the effects of object position in the working volume on the accuracy of 3D reconstruction, using four different camera calibration approaches: 1) the classical DLT, 2) the nonlinear DLT, 3) the 2D plate and 4) the wand calibration. The DVideo kinematic analysis system was used for underwater data acquisition. The system consisted of two gen-locked Ba...