Skin-stretch Haptic Feedback Augmentation Improves Performance in a Simulated Laparoscopic Palpation Task.

Laparoscopic surgery brings substantial benefits to patients. However, it remains challenging for surgeons because of motion constraints and perception limitations. Notably, the perception of interactions with organs is largely compromised. This paper evaluates the effectiveness of a forearm-based skin-stretch haptic feedback system rendering surgical tool tip force. Twenty novice participants had to discern the stiffness of samples to investigate stiffness perception in a simulated laparoscopic task. The experimental protocol involved manipulating samples with three difficulty levels and testing three feedback conditions: no augmentation, visual feedback, and tactile feedback. The results demonstrate that feedback significantly enhances the success rate of laparoscopic palpation tasks. The proposed tactile feedback boosts confidence and task speed and reduces peak force and perceived workload. These benefits become even more pronounced when difficulty increases. These promising findings affirm the value of skin-stretch haptic feedback augmentation in improving performance for simulated laparoscopy tasks, paving the way for more integrated and deployable devices for the operating room.

Adaptative damping assistance in bimanual laparoscopic surgery.

PURPOSE: Laparoscopic surgery has demonstrated various advantages for the patients' care, but also presents some difficulties for the surgeons, such as kinematic restrictions. Robotic comanipulation, in which control of instruments is shared between the robot and the surgeon, can provide adaptative damping assistance which allows stabilisation of movements. The objective of the present study was to determine the contribution of this assistance on a bimanual laparoscopic task. METHODS: Adaptative damping was studied on Peg Transfer task, performed by eighteen surgery-naive subjects. This exercise was repeated seven times without (Classic repetitions) and seven times with comanipulated robots (Robot repetitions), in a randomised order. We measured task performance, using Peg Transfer score; gesture performance, using hand oscillations and travelled distance; eye-tracking movements as an indicator of emergence of expertise. Participants' perceived workload was assessed by NASA TLX questionnaire, and difference in impression between the two conditions by UEQ questionnaire. RESULTS: Adaptative damping improved gesture performance (oscillations F(1,17) = 23.473, p < 0.001, η2 = 0.580), with a statistically significant simple effect on the tool oscillation for both non-dominant (p < 0.001) and dominant hands (p = 0.005), without influencing task performance (mean Peg Transfer score t(17) = 0.920, p = 0.382, d = 0.29), but deteriorating eye-tracking movements associated with emergence of expertise (mean fixation rate per second F(1,17) = 6.318, p = 0.022, η2 = 0.271), at the cost of a high perceived workload (NASA TLX score 59.78/100). CONCLUSION: Assistance by adaptative damping applied by comanipulated robots improved gesture performance during a laparoscopic bimanual task, without impacting task's performance without allowing the emergence of comportments associated with an expertise, and at the cost of a high perceived workload. Further research should investigate this assistance on more precise and clinical tasks performed by professionals.

Real Time Estimator to Perform Targeted Biopsies With a Free-Wrist Robot Despite Large Deformations of the Insertion Orifice.

In the context of keyhole surgery, and more particularly of uterine biopsy, the fine automatic movements of a surgical instrument held by a robot with 3 active DOF's require an exact knowledge of the point of rotation of the instrument. However, this center of rotation is not fixed and moves during an examination. This paper deals with a new method of detecting and updating the interaction matrix linking the movements of the robot with the surgical instrument. This is based on the method of updating the Jacobian matrix which is named the "Broyden method". It is able to take into account body tissue deformations in real time in order to improve the pointing task for automatic movements of a surgical instrument in an unknown environment.

Precisely positioning the tip of an instrument inserted through an orifice with a free wrist robot: application to prostate biopsies.

PURPOSE: Robots with a spherical unactuated wrist can be used for minimally invasive surgery. With such a robot, positioning the wrist center controls the instrument tip position when assuming that the insertion site behaves like a lever with a fixed and known fulcrum. In practice, this assumption is not always respected. In this paper we first study the practical consequences of this problem in terms of tip precision positioning. We then propose a robotic control scheme that improves the precision compared to the fixed point assumption approach. METHODS: In the first part of the paper, data recorded during robot-assisted transrectal needle positioning for prostate biopsies (nine patients) are exploited to quantify the positioning error induced by the use of a fixed point hypothesis in the positioning process. In the second part of the paper advanced control techniques allow for the online identification of a locally linear system that describes a model characterized by anisotropy and center displacement. A laboratory apparatus is used to demonstrate the resulting improvement on tip positioning precision. RESULTS: Errors obtained by processing the clinical data reach 7.5 mm at the tip in average. Errors obtained with the laboratory apparatus drop from 2.4 mm in average to 0.8 mm when using real-time model update.

Prostate biopsies assisted by comanipulated probe-holder: first in man.

PURPOSE: A comanipulator for assisting endorectal prostate biopsies is evaluated through a first-in-man clinical trial. This lightweight system, based on conventional robotic components, possesses six degrees of freedom. It uses three electric motors and three brakes. It features a free mode, where its low friction and inertia allow for natural manipulation of the probe and a locked mode, exhibiting both a very low stiffness and a high steady-state precision. METHODS: Clinical trials focusing on the free mode and the locked mode of the robot are presented. The objective was to evaluate the practical usability and performance of the robot during clinical procedures. A research protocol for a prospective randomized clinical trial has been designed. Its specific goal was to compare the accuracy of biopsies performed with and without the assistance of the comanipulator. RESULTS: The accuracy is compared between biopsies performed with and without the assistance of the comanipulator, across the 10 first patients included in the trial. Results show a statistically significant increase in the precision.

Robot guidance of an ultrasound probe toward a 3D region of interest detected through X-ray mammography.

PURPOSE: This research is situated in the context of breast cancer detection where the standard procedure is the succession of an initial mammography (MX) examination and a supplementary ultrasound (US) scan. One major difficulty of this procedure results from the fact that breast geometry changes between both examinations due to different patient's positions. The proposed system facilitates this combined examination by keeping the breast geometry and by adding a US probe guidance robot to the mammography system. METHODS: A comanipulation system is set up where the robot and user simultaneously manipulate the probe toward the target previously localized in MX images. Calibration procedures and robot control are detailed. RESULTS: A test protocol was presented to conduct two tests that are both related to the medical application. The first tests aim at evaluating robot guidance for localizing a lesion which was previously defined in the X-ray images. The second tests aim at quantifying robot influence when scanning a target lesion. The studied task consists of a pointing/scanning exercise, where the US beam intersects a breast lesion. CONCLUSIONS: The experiments show a significant increase in examination quality when using robot guidance as compared to the nonassisted examination.

Underactuated comanipulation for ultrasound breast exams.

We investigate the possibility of providing adequate task assistance using under-actuated robots for human-robot tool co-manipulation. This novel approach optimizes robot-user synergy without taking into account any a priori knowledge of parameters depending on the user. Six different actuation modes were compared for a localization and scanning task. The best performance gain was achieved for 1 degree of under-actuation.