Robotic Minimally Invasive Surgery Research Articles

Quality of life after robotic versus conventional minimally invasive cancer surgery: a systematic review and meta-analysis.

Optimizing postoperative quality of life (QoL) is an essential aspect of surgical oncology. Minimally invasive surgery (MIS) decreases surgical morbidity and improves QoL outcomes. This meta-analysis aimed to compare post-operative QoL after oncologic resections using different MIS modalities. The PubMed, Embase, Scopus, and CENTRAL databases were searched for articles that compared post-operative QoL in patients undergoing video-assisted thoracoscopic (VATS) or laparoscopic surgery (LS) versus robotic surgery (RS) for malignancy. Quality assessment was performed using the ROBINS-I and Cochrane Risk of Bias 2 (RoB-2) tools. Meta-analysis was performed using an inverse-variance random effects model. 27 studies met the inclusion criteria, including 5 randomized controlled trials (RCTs). 15 studies had a low risk of bias, while 11 had a moderate risk of bias and 1 had serious risk of bias. 8330 patients (RS: 5090, LS/VATS: 3240) from across 25 studies were included in the meta-analysis. Global QoL was significantly better after robotic surgery in the pooled analysis overall (SMD: -0.28 [95% CI: -0.49, -0.08]), as well as in the prostatectomy and gastrectomy subgroups. GRADE certainty of evidence was low. Analysis of EPIC-26 subdomains also suggested greater sexual function after robotic versus laparoscopic prostatectomy. Robotic and conventional MIS approaches produce similar postoperative QoL after oncologic surgery for various tumor types, although advantages may emerge in some patient populations. Our results may assist surgeons in counseling patients who are undergoing oncologic surgery.

First-in-human validation of a DROP-IN β-probe for robotic radioguided surgery: defining optimal signal-to-background discrimination algorithm.

In radioguided surgery (RGS), radiopharmaceuticals are used to generate preoperative roadmaps (e.g., PET/CT) and to facilitate intraoperative tracing of tracer avid lesions. Within RGS, there is a push toward the use of receptor-targeted radiopharmaceuticals, a trend that also has to align with the surgical move toward minimal invasive robotic surgery. Building on our initial ex vivo evaluation, this study investigates the clinical translation of a DROP-IN β probe in robotic PSMA-guided prostate cancer surgery. A clinical-grade DROP-IN β probe was developed to support the detection of PET radioisotopes (e.g., 68Ga). The prototype was evaluated in 7 primary prostate cancer patients, having at least 1 lymph node metastases visible on PSMA-PET. Patients were scheduled for radical prostatectomy combined with extended pelvic lymph node dissection. At the beginning of surgery, patients were injected with 1.1MBq/kg of [68Ga]Ga-PSMA. The β probe was used to trace PSMA-expressing lymph nodes in vivo. To support intraoperative decision-making, a statistical software algorithm was defined and optimized on this dataset to help the surgeon discriminate between probe signals coming from tumors and healthy tissue. The DROP-IN β probe helped provide the surgeon with autonomous and highly maneuverable tracer detection. A total of 66 samples (i.e., lymph node specimens) were analyzed in vivo, of which 31 (47%) were found to be malignant. After optimization of the signal cutoff algorithm, we found a probe detection rate of 78% of the PSMA-PET-positive samples, a sensitivity of 76%, and a specificity of 93%, as compared to pathologic evaluation. This study shows the first-in-human use of a DROP-IN β probe, supporting the integration of β radio guidance and robotic surgery. The achieved competitive sensitivity and specificity help open the world of robotic RGS to a whole new range of radiopharmaceuticals.

Implementation of a Virtual Reality Based Digital-Twin Robotic Minimally Invasive Surgery Simulator.

The rapid development of computers and robots has seen robotic minimally invasive surgery (RMIS) gradually enter the public's vision. RMIS can effectively eliminate the hand vibrations of surgeons and further reduce wounds and bleeding. However, suitable RMIS and virtual reality-based digital-twin surgery trainers are still in the early stages of development. Extensive training is required for surgeons to adapt to different operating modes compared to traditional MIS. A virtual-reality-based digital-twin robotic minimally invasive surgery (VRDT-RMIS) simulator was developed in this study, and its effectiveness was introduced. Twenty-five volunteers were divided into two groups for the experiment, the Expert Group and the Novice Group. The use of the VRDT-RMIS simulator for face, content, and structural validation training, including the peg transfer module and the soft tissue cutting module, was evaluated. Through subjective and objective evaluations, the potential roles of vision and haptics in robot surgery training were explored. The simulator can effectively distinguish surgical skill proficiency between experts and novices.

Impact of Minimally Invasive Approach to Radical Cystectomy in Bladder Cancer Patients with Malnutrition

Malnutrition is associated with higher rates of complications following radical cystectomy (RC) for the treatment of muscle-invasive bladder cancer. The newer robotic approach to RC has yet to be analyzed against the open approach in malnourished patients with respect to perioperative complications. A retrospective cohort analysis of RC patients with a postoperative diagnosis of bladder cancer and non-disseminated disease was performed. Malnourishment was defined as either low serum albumin (<3.5 g/dL), >10% 6-month preoperative weight loss, or BMI <18.5 kg/m2). Multivariable and generalized logistic regression were used for categorical and continuous outcomes respectively. Malnourishment was associated with greater systemic sepsis, bleeding transfusions, 30-day mortality, postoperative C. difficile infection, and days from operation to discharge (DOD) (all P < 0.05). In malnourished patients, robotic approach was associated with lower adjusted odds of bleeding transfusions (aOR = 0.51, P < 0.05) and fewer adjusted days from operation to discharge (β[SE]= −5.2[1.1], P < 0.05) compared to open. Typical benefits seen with minimally-invasive robotic surgery translate to malnourished patients, although they were still prone to longer hospital stay than their adequately nourished counterparts. Robotic approach to RC may help mitigate the increased need for transfusions and longer DOD seen in malnourishment and may be preferable for patients with preoperative nutritional deficits.

493 One and Two-Level Robotic MIS TLIF With Expandable Implants Demonstrates a Favorable Safety Profile and Improved Alignment Parameters

INTRODUCTION: Minimally invasive surgery (MIS) transforaminal lumbar interbody fusion (TLIF) is an established technique, but continues to evolve with the development of expandable titanium cages and robotic screw insertion. METHODS: This retrospective case series assessed clinical data, complications, and radiographic outcomes at short term follow-up. Screw placement was performed using intraoperative 3D imaging and robotic navigation, and TLIFs were performed via complete facetectomy from a unilateral trajectory in line with pedicle screws using titanium expandable cages. RESULTS: 22 patients, 32 levels, and 108 inserted screws were analyzed. Implants included curved cages in 14 levels, 2 straight cages (diverging “V” pattern) in 12 levels, and a single straight cage in 6 levels. 21/22 patients (95%) had decreased pain. 4/22 patients (18%) experienced complications including deep infection causing screw pullout (requiring revision), painful radiculopathy, contact dermatitis (glue), and UTI. 108/108 screws (100%) showed excellent position. Increases were observed in average segmental lordosis (4.3 ± 4.9°), anterior disc height (6.6 ± 3.5 mm), posterior disc height (4.1 ± 2.1 mm), and foraminal height (5.0 ± 3.1 mm). Improved alignment was observed in 3/3 patients (100%) with SVA &gt; 50 mm (78.3 ± 13.3 mm to 41.7 ±14.3 mm), 3/4 (75%) with pelvic tilt &gt;=25° (30.3 ± 1.5° to 22.7 ± 4.0°), 5/5 (100%) with lumbopelvic mismatch &gt; 10° (PI – LL: 21.4 ± 2.1° to 9.8 ± 8.5°), 13/13 (100%) with anterolisthesis (6.5 ± 2.3 mm to 1.8 ± 1.9 mm), and 4/4 (100%) with segmental coronal imbalance &gt;5° (8.0 ± 3.2° to 2.8 ± 1.3°). CONCLUSIONS: Robotic MIS TLIF with expandable cages has a favorable safety profile, successful short-term clinical results, and is effective at correcting mild spinal malalignment.

Sensitivity analysis of a double-parallelogram based RCM mechanism used for MIS robots

Parallelogram-based remote center-of-motion (RCM) mechanisms are extensively used to design robots for minimally invasive surgery (MIS). For their kinematic modeling, classically, it is assumed that link parameters of the opposite sides of constituting parallelograms are equal which made the RCM an invariant point and simplified the prescribed modeling process. However, link parameter equality does not exist in actual practice due to the inevitable constraints of manufacturing, assembly and testing/measurement, etc. Consequently, the RCM and surgical end-effector deviate from their theoretically designed positions. This paper introduces a novel approach to model the kinematics of parallelogram-based mechanisms by accounting for the error in manufactured link parameters. Additionally, it works out the types, possible ways, order, and nature of the said deviation. Further, a double-parallelogram-based RCM mechanism is adopted to demonstrate the proposed concept, and a prototype of the same is manufactured using laser micromachining and rapid prototyping techniques. Thereafter, the developed kinematic models are validated both analytically and physically. In contrast to the results given by the conventional kinematic modeling approach, the results obtained through the proposed approach and performed experiment showed better agreement with each other. The sensitivity of RCM and surgical end-effector to the inequalities, involved in the manufactured prototype, is revealed through several plots in the Matlab environment. A significant improvement in positional accuracy of the RCM and surgical end-effector have been achieved. It proves the efficacy of the presented method and it is believed that it applies to other parallelogram-based mechanisms as well.

Design and prototyping of an accelerometer based parallel manipulator for endoscope position control

The advancement of embedded controllers in minimally invasive robotic surgery (MIRS) provides an innovative and safe alternative to traditional open surgery. This paper illustrates the Accelerometer-based Embedded prototype of 4 link novel parallel manipulator design and endoscope end position control scheme. The parallel manipulator proposed is of 4 leg quadra model with 4 servo actuators to drive the end effector to which endoscope camera integrated with micro electro-mechanical system (MEMS) accelerometer. The parallel manipulator is modeled in Coppeliasim computer-aided design (CAD) and embedded control logic is implemented in the ATmega328P microcontroller. The achieved end effector movement is +/-10cm from the ground clearance validated it in CAD tool. The potentiometer-based position control of the endoscope and its image magnification is recorded. The internet of things (IoT) infrastructure extension to the demonstrated protype is proposed. This cost-effective model is compared with the existed models available in the market.

A class of spatial remote center-of-motion mechanisms and its forward kinematics

AbstractRobot-assisted minimally invasive surgery (MIS) has shown tremendous advances over the traditional technique. A crucial challenge for developing a MIS robot is the kinematic design of the remote center-of-motion (RCM) mechanism. In this paper, a class of spatial RCM mechanism is analyzed. They are obtained by generating virtual parallelograms. The main process is to construct a line that passes through a fixed point under the mechanical constraint. The axis of the surgical tool is then constrained to parallel with that line. Hence, due to the geometrical feature of the parallel lines, the axis of the surgical tool will always pass through a fixed point, i.e., the RCM point. Due to the specially designed structure, the fixed point does not need to be physically belonging to the mechanism. The geometrical analysis method is employed to obtain the closed-form solution of the forward kinematics of the proposed mechanisms. Due to the high load capacity of parallel mechanism, the robots based on the proposed RCM mechanisms have promising applications as an external positioner to be used in robotic single-port surgeries.

Evaluation of user-interfaces for controlling movements of virtual minimally invasive surgical instruments.

Recent tele-mentoring technologies for minimally invasive surgery (MIS) augments the operative field with movements of virtual surgical instruments as visual cues. The objective of this work is to assess different user-interfaces that effectively transfer mentor's hand gestures to the movements of virtual surgical instruments. A user study was conducted to assess three different user-interface devices (Oculus-Rift, SpaceMouse, Touch Haptic device) under various scenarios. The devices were integrated with a MIS tele-mentoring framework for control of both manual and robotic virtual surgical instruments. The user study revealed that Oculus Rift is preferred during robotic scenarios, whereas the touch haptic device is more suitable during manual scenarios for tele-mentoring. A user-interface device in the form of a stylus controlled by fingers for pointing in 3D space is more suitable for manual MIS, whereas a user-interface that can be moved and oriented easily in 3D space by wrist motion is more suitable for robotic MIS.

Vision-Guided Autonomous Robotic Electrical Bio-Impedance Scanning System for Abnormal Tissue Detection

In cancer surgery, the correct localization of cancerous tissue is critical for the success of the surgery. Specifically, the surgical goal is to remove the malignant tissue completely while preserving the maximum amount of healthy tissue. Unfortunately, limited technologies are available for intra-operative assessment of tumor margin in Robotic Minimally Invasive Surgery (RMIS). This work presents a vision-based autonomous robotic scanning system for abnormal tissue detection. A stereo vision system, including dense 3D surface reconstruction and tissue tracking, is used to control the scanning motion to compensate for tissue motion and deformation. A high level control strategy allows to control a robot arm to scan autonomously the tissue by means of a monopolar forceps measuring the Electric Bio-Impedance (EBI) of the tissue. The acquired information is used for discriminating cancerous from healthy tissue in real-time, and this information is presented as an impedance map overlaid on the endoscopic video using Augmented Reality (AR). The proposed system performance is evaluated on ex-vivo animal tissues, through experiments simulating the identification and localization of hepatic cancer for resection surgery. Quantitative results show that the system is able to autonomously scan the area of interest and provide a tissue characterization with an accuracy over 82%.

Unsupervised Anomaly Detection for a Smart Autonomous Robotic Assistant Surgeon (SARAS) Using a Deep Residual Autoencoder

Anomaly detection in Minimally-Invasive Surgery (MIS) traditionally requires a human expert monitoring the procedure from a console, whereas automated anomaly detection systems in this area typically rely on classical supervised learning. Anomalous surgical events, however, are rare, making it difficult to capture data to train a model in a supervised fashion. In this work we propose an unsupervised approach to anomaly detection for robotic MIS based on deep residual autoencoders. The idea is to make the autoencoder learn the `normal' distribution of the data and detect abnormal events deviating from this distribution by measuring a reconstruction error. The model is trained and validated upon both the publicly available Cholec80 dataset and a set of videos captured on procedures using artificial anatomies (`phantoms') as part of the Smart Autonomous Robotic Assistant Surgeon (SARAS) project. The system achieves recall and precision equal to 78.4%, 91.5%, respectively, on Cholec80 and of 95.6%, 88.1% on the SARAS phantom dataset. The system was developed and deployed as part of the SARAS platform for real-time anomaly detection with a processing time of 25 ms per frame.

Full-Dimensional Intuitive Motion Mapping Strategy for Minimally Invasive Surgical Robot With Redundant Passive Joints

AbstractAdding redundant passive joints to a robotic arm is an effective way to make the robot overcome the inherent incision constraint of minimally invasive surgery (MIS). However, due to the limited motion accuracy, it is difficult to realize full-dimensional intuitive motion based on traditional multi-axis coordinated control technology in this kind of MIS robots. To solve this problem, a separated position and orientation mapping strategy for MIS robot with redundant passive joints is proposed in the paper. The position and orientation mapping of the strategy are realized by coordinate motion control and joint direct control technique, respectively. To realize the intuitive motion under this condition, an inverse motion mapping method is further proposed. Compared with the existing mapping strategy, the proposed strategy is much more compact as the orientation mapping is greatly simplified. A large number of in vivo trials based on the newly developed prototype have been conducted and results fully verify the effectiveness of the proposed strategy.

Implementation of fixed point of minimally invasive surgical robot: a survey

Minimally invasive surgery(MIS)has the advantages of less trauma and quick recovery, so it is favored by patients. However, there are more requirements for surgeons' skill and experience in MIS. Combining robot-assisted tech-nology with MIS can improve the quality of surgery and shorten the learning time for surgeons. Besides, with the help of robot-assisted technology, remote surgery can be achieved. Because of small incisions in MIS, the manipu-lator must pass through a fixed point during movement, which is the key point to develop the MIS robot and an obvious feature of the MIS robots. The ways whose classification is made into mechanisms with redundant degrees of freedom (DOF) and constrained by mechanisms to meet the requirement are summarized, and the principles, advantages, and drawbacks of each method are analyzed in this article. Based on summarizing the research results and analyzing the key technologies, the insight into future work is proposed.

A single institution experience of minimally invasive liver surgery: 12 years after the Louisville statement where do we stand?

Presenter: Patrick Salibi MD | Atrium Health Background: Despite significant improvements in perioperative outcomes, minimally invasive surgery (MIS) was broadly adopted relatively late in hepatic surgery. The Louisville Consensus Statement in 2008 recommended indications for MIS liver resection to solitary lesions < 5cm in segments 2 through 6. However, as MIS technology advanced and surgeon comfort increased, the indications for MIS liver resection have expanded. The aims of this study are to present an institutional experience of developing an MIS liver surgery program and to assess outcomes that define an institutional learning curve for these procedures. Methods: A prospectively maintained registry of all hepatic surgical cases performed at a single high-volume tertiary care center was queried from January 2008 to December of 2019. Retrospective record review was performed, collecting data including patient demographics, baseline laboratory values, surgical details, conversion to an open approach, estimated blood loss, blood transfusions, operative time, length of stay, complications, re-admissions and mortality. All data collection and record review were approved by the Institutional Review Board. Results: Our institution performed 1098 both open and MIS liver resection during the study period as well as an additional 842 microwave ablation procedures. Of these 501 patients underwent MIS liver resection and had complete data to perform accurate review. When assessing an institutional learning curve there was no significant difference noted over time for perioperative and postoperative outcomes including operative time, need for blood transfusions, length of stay, readmissions or morbidity/mortality. Consistent measures that improved overtime and remained stable for both laparoscopic and robotic MIS approaches, were conversion rate and estimated blood loss. When broken up by 4-year periods the conversion rate was noted to be 13.18% (2008-2011), 7.28% (2012-2015) and 4.64% (2016-2019). Estimated blood loss improved similarly during each epoch: 634ml (2008-2011), 483ml (2012-2015), and 348ml (2016-2019). A ceiling effect of percent MIS cases performed over time increased incrementally from 47.66% (2008-2011) to 67.98% (2012-2015) and plateaued at 75.85% (2016-2019). Conclusion: This study presents 12 years of data from a single institution and proposes that percent conversion rate and estimated blood loss appear to the be the best institutional predictors of learning curve given that over time introduction of junior faculty likely effects other perioperative and postoperative outcomes. Ceiling effect can be viewed as another measure of an institutions learning curve and again showed consistent increase overtime to a plateau of 75-80% which one would expect at a high-volume liver center were the need for maximally invasive surgery for major resections remains a necessity.

Impact of Minimal Invasive Robotic Surgery on Recovery From Postoperative Ileus and Postoperative Gastrointestinal Tract Dysfunction.

Postoperative gastrointestinal tract (GIT) dysfunction (POGD) and postoperative ileus (POI) are common symptoms resulting from small or large bowel surgery associated with extended hospitalizations, increase risk of infections and billions of dollars in health care costs. Open surgery is associated with higher gut surgical trauma / manipulation and worse outcomes compared to minimal invasive surgery. Robotic Surgery may offer added benefit to Colon Enhanced Recovery After Surgery (CERAS) protocols but do not solve the problem. Ultimately, a better understanding of the pathogenic mechanisms of POI and POGD can lead to prophylaxis and enhanced recovery after surgery. The impact of High Pressure Pneumoperitoneum and gut surgical manipulation on GIT dysfunction deserve further investigation.

Camera-Robot Calibration for the da Vinci® Robotic Surgery System.

The development of autonomous or semi-autonomous surgical robots stands to improve the performance of existing teleoperated equipment, but requires fine hand-eye calibration between the free-moving endoscopic camera and patient-side manipulator arms (PSMs). A novel method of solving this problem for the da Vinci® robotic surgical system and kinematically similar systems is presented. First, a series of image-processing and optical-tracking operations are performed to compute the coordinate transformation between the endoscopic camera view frame and an optical-tracking marker permanently affixed to the camera body. Then, the kinematic properties of the PSM are exploited to compute the coordinate transformation between the kinematic base frame of the PSM and an optical marker permanently affixed thereto. Using these transformations, it is then possible to compute the spatial relationship between the PSM and the endoscopic camera using only one tracker snapshot of the two markers. The effectiveness of this calibration is demonstrated by successfully guiding the PSM end effector to points of interest identified through the camera. Additional tests on a surgical task, namely grasping a surgical needle, are also performed to validate the proposed method. The resulting visually-guided robot positioning accuracy is better than the earlier hand-eye calibration results reported in the literature for the da Vinci® system, while supporting intraoperative update of the calibration and requiring only devices that are already commonly used in the surgical environment.

An External Force Sensing System for Minimally Invasive Robotic Surgery

Minimally invasive robotic surgery (MIRS) has revolutionized surgical procedures. However, compared to classic laparoscopy, the surgeon must rely only on visual perception because of the lack of force feedback. In this article, a new noninvasive force feedback system is proposed and evaluated. Extending the work by Fontanelli (2017), where preliminary results were presented, a solution based on a novel force sensor placed in the terminal part of the trocar is shown in detail. With respect to the state of the art, our system allows measuring the interaction forces between the surgical instrument and the environment inside the patient's body without any changes to the instrument structure and with full adaptability to different robotic platforms and surgical tools. Using a commercial force-torque sensor as ground truth, the static and dynamic characterization of the sensor is provided together with an extensive experimental validation. Finally, a simple and intuitive application of the proposed sensing system in a realistic surgical scenario is presented.

Survival after a nationwide adoption of robotic minimally invasive surgery for early-stage cervical cancer – A population-based study

AimLately, the safety of minimally invasive surgery (MIS) in the treatment of cervical cancer (CC) has been questioned. This study aimed to evaluate the risk of recurrence and survival after a nationwide adoption of robotic MIS for the treatment of early-stage CC in Denmark. MethodsPopulation-based data on all Danish women with early-stage CC, who underwent radical hysterectomy January 1st 2005–June 30th 2017 were retrieved from the Danish Gynecologic Cancer Database and enriched with follow-up data on recurrence, death and cause of death. The cohort was divided into two groups according to the year of robotic MIS introduction at each cancer centre. Chi-squared or Fischer test, the Kaplan Meier method and multivariate Cox regression were used for comparison between groups. ResultsOne thousand one hundred twenty-five patients with CC were included; 530 underwent surgery before (group 1) and 595 underwent surgery after (group 2) the introduction of robotic MIS. The 5-year rate of recurrence was low: 8.2% and 6.3% (p = 0.55) in group 1 and 2, respectively. In adjusted analyses, this corresponded to a five-year disease-free survival, hazard ratio (HR) 1.23 [95% confidence interval (CI) 0.79-1.93]. No difference in site of recurrence (P = 0.19) was observed. The cumulative cancer-specific survival was 94.1% and 95.9% (P = 0.10) in group 1 and 2, respectively, corresponding to a HR 0.60 [95% CI 0.32–1.11] in adjusted analyses. ConclusionIn this population-based cohort study, the Danish nationwide adoption of robotic MIS for early-stage CC was not associated with increased risk of recurrence or reduction in survival outcomes.

Development of a New Medical Robot System for Minimally Invasive Surgery

This article presents the development of a new medical robot system comprising a spherical remote center motion (RCM) mechanism with modular design and two mechanical decoupling methods for Minimally Invasive Surgery (MIS). We achieved excellent comprehensive performance indices through a novel multi-objective optimization model comprising four optimization objective functions, three constrained conditions and two optimization variables. In order to enhance the manipulability, remove the coupling between motors, and reduce the control difficulty, two new decoupling mechanism means were proposed to remove coupling motion between the wrist and pincers, coupling motion between the translational joint of mobile platform and four interface disks of surgical instrument as a results of rear drive motor, respectively. The control system architecture is designed to include intuitive motion control, incremental motion control, and proportional motion control. Master-slave attitude registration and surgical instrument replacement strategies improve the master-slave control efficiency. We tested the spherical RCM mechanism performance indices and developed two mechanical decoupling methods and a master-slave control algorithm. Our experimental test results validated that fixing point accuracy, the coupling motions, the positioning and repeated positioning accuracy of the MIS robot, and master-slave control algorithm meet the requirements of MIS. Successful animal experiments confirmed effectiveness of the novel MIS robot system.

Texture differentiation using audio signal analysis with robotic interventional instruments

Robotic minimally invasive surgery (RMIS) has played an important role in the last decades. In traditional surgery, surgeons rely on palpation using their hands. However, during RMIS, surgeons use the visual-haptics technique to compensate the missing sense of touch. Various sensors have been widely used to retrieve this natural sense, but there are still issues like integration, costs, sterilization and the small sensing area that prevent such approaches from being applied. A new method based on acoustic emission has been recently proposed for acquiring audio information from tool-tissue interaction during minimally invasive procedures that provide user guidance feedback. In this work the concept was adapted for acquiring audio information from a RMIS grasper and a first proof of concept is presented. Interactions of the grasper with various artificial and biological texture samples were recorded and analyzed using advanced signal processing and a clear correlation between audio spectral components and the tested texture were identified.