A micro motion sensing system for micromanipulation tasks

Abstract

An optical-based motion sensing system has been developed for real-time sensing of instrument motion in micromanipulation. The main components of the system consist of a pair of position sensitive detectors (PSD), lenses, an infrared (IR) diode that illuminates the workspace of the system, a non-reflective intraocular shaft, and a white reflective ball attached at the end of the shaft. The system calculates 3D displacement of the ball inside the workspace using the centroid position of the IR rays that are reflected from the ball and strike the PSDs. In order to eliminate inherent nonlinearity of the system, calibration using a feedforward neural network is proposed and presented. Handling of different ambient light and environment light conditions not to affect the system accuracy is described. Analyses of the whole optical system and effect of instrument orientation on the system accuracy are presented. Sensing resolution, dynamic accuracies at a few different frequencies, and static accuracies at a few different orientations of the instrument are reported. The system and the analyses are useful in assessing performance of hand-held microsurgical instruments and operator performance in micromanipulation tasks.

Multistep Prediction of Physiological Tremor Based on Machine Learning for Robotics Assisted Microsurgery

“…Physiological Tremor Data Collection 1) Experimental Setup: Tremor recordings were performed through the micro motion sensing system (M2S2) and a sensorized stylus [6]. M2S2 provides a measurement in a 10 × 10 × 10 mm 3 workspace, with a resolution of 0.7 μm and minimum accuracy of 98% [34]. The sensorized stylus is designed with similar mass characteristics to a typical surgical instrument and a reflector ball at its tip.…”

“…M2S2 calculates the 3-D displacement of the ball inside the workspace using the centroid position of the infrared rays that are reflected from the ball and strike the photo sensitive diodes. For more details about the design of M2S2 and stylus and the data acquisition with M2S2, please refer to [6] and [34].…”

“…Of these, phase delay is the major factor that affects the tremor compensation adversely in real-time [5]. The prime source for this phase delay is the employment of linear filters in the tremor filtering and compensation procedure [15], [34]. In the sensing stage, a delay of 3 ms was identified due to the presence of an on-board low-pass filter in accelerometers.…”

“…15. The tremor compensation instrument (Itrem [34]) which contains accelerometers (ADXL 203, analog devices, USA), was mounted on the nanopositioning stage (P-561.3CD from Physik Instrumente, Germany) as shown in Fig. 15.…”

Multi-step tremor prediction autoregressive (AR) model and Kalman filter (KF) for surgical robotic applications

“…Tremor like motion is generated using a commercially available nanopositioning stage (P-561.3CD from PhysikInstrumente, Germany) on which a physiological tremor compensation instrument consisting of accelerometers is mounted. For more information regarding the placement of accelerometers and other information, see [15], [17]. The nanopositioning stage is driven in one axis to replicate the tremor motion recorded from a surgeon (S#1, pointing task) within 100nm, the maximum range of the stage.…”