Richard Voyles

Dr. Richard Voyles

orcid

Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 January 2023 in IEEE Transactions on Medical Robotics and Bionics
Verified
Journal Article
Closed access
GGGlebys Gonzalez
Glebys Gonzalez
MBMythra Balakuntala
Mythra Balakuntala
MAMridul Agarwal
Mridul Agarwal
TLTomas Low
Tomas Low
BKBruce Knoth
Bruce Knoth
JWJuan Wachs
Juan Wachs
In remote, rural, and disadvantaged areas, telesurgery can be severely hindered by limitations of communication infrastructure. In conventional telesurgery, delays as small as 300ms can produce fatal surgical errors. To mitigate the effect of communication delays during telesurgery, we introduce a semi-autonomous system that decouples the user interaction from the robot execution. This system uses a physics-based simulator where a surgeon can demonstrate individual surgical subtasks, with immediate graphical feedback. Each subtask is performed asynchronously, unaffected by communication latency, jitter, and packet loss. A surgical step recognition module extracts the intended actions from the observed surgeon-simulation interaction. The remote robot can perform each one of these actions autonomously. The action recognition system leveraged a transfer learning approach that minimized the data needed during training, and most of the learning is obtained from simulated data. We tested this system in two tasks: fluidsubmerged peg transfer (resembling bleeding events) and surgical debridement. The system showed robustness to delays of up to 5 seconds, maintaining a performance rate of 87% for peg transfer and 88% for debridement. Also, the framework reduced the completion time under delays by 45% and 11% during peg transfer and debridement, respectively.

1 November 2019
Verified
Conference Paper
Open access
NMNaveen Madapana
Naveen Madapana
MRMasudur Rahman
Masudur Rahman
NSNatalia Sanchez-Tamayo
Natalia Sanchez-Tamayo
MBMythra V. Balakuntala
Mythra V. Balakuntala
GGGlebys Gonzalez
Glebys Gonzalez
JWJuan Wachs
Juan Wachs
Datasets are an essential component for training effective machine learning models. In particular, surgical robotic datasets have been key to many advances in semi-autonomous surgeries, skill assessment, and training. Simulated surgical environments can enhance the data collection process by making it faster, simpler and cheaper than real systems. In addition, combining data from multiple robotic domains can provide rich and diverse training data for transfer learning algorithms. In this paper, we present the DESK (DExterous Surgical SKills) dataset. It comprises a set of surgical robotic skills collected during a surgical training task using three robotic platforms: the Taurus II robot, Taurus II simulated robot, and the YuMi robot. This dataset was used to test the idea of transferring knowledge across different domains (e.g. from Taurus to YuMi robot) for a surgical gesture classification task with seven gestures/surgemes. We explored two different scenarios: 1) No transfer and 2) Domain transfer (simulated Taurus to real Taurus and YuMi robots). We conducted extensive experiments with three supervised learning models and provided baselines in each of these scenarios. Results show that using simulation data during training enhances the performance on the real robots, where limited real data is available. In particular, we obtained an accuracy of 55% on the real Taurus data using a model that is trained only on the simulator data, but that accuracy improved to 82% when the ratio of real to simulated data was increased to 0.18 in the training set.

19 July 2022 in Advanced Engineering Materials
Verified
Journal Article
Open access
JFJinsheng Fan
Jinsheng Fan
Brittany NewellBrittany Newell
Brittany Newell
JGJose Garcia-Bravo
Jose Garcia-Bravo
RVRichard Voyles
Richard Voyles
RNRobert Nawrocki
Robert Nawrocki
Additive manufacturing, commonly known as 3D printing, significantly simplifies the manufacturing process for soft electronics. This work demonstrates the feasibility of a fully 3D‐printed flexible poly(vinylidene fluoride) (PVdF) capacitive temperature sensor. The sensor is constructed using fused deposition modeling (FDM)‐printed PVdF film as the dielectric (thickness ≈180–280 μm) sandwiched between two parallel Direct Ink Writing (DIW) printed silver electrodes (entire device thickness ≈200–380 μm). The motion of the nozzle can facilitate mechanical drawing to the molten PVdF filament, which is a necessary condition to increase the β‐phase content (critical for the sensitivity of the sensor). With optimized printing parameters, the highest β‐phase content (21.30%) is achieved when printing with a nozzle temperature of 200 °C and a print speed of 70 mm s−1. The research demonstrates the application of the device as a temperature sensor by applying heating‐and‐cooling cycles from room temperature (25 °C) up to 140 °C while measuring the capacitance as a function of frequency under different temperatures. The sensor exhibits a stable sensitivity of 3 pF °C−1 at 102 Hz and higher frequencies and improved sensitivities at frequencies higher than 102 Hz after dielectric polarization via the corona poling method.

10 April 2024 in IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Verified
Journal Article
Closed access
DRDeepak Raina
Deepak Raina
SCSheragaru Hanumanthappa Chandrashekhara
Sheragaru Hanumanthappa Chandrashekhara
RVRichard Voyles
Richard Voyles
JWJuan Wachs
Juan Wachs
SSSubir Kumar Saha
Subir Kumar Saha
Autonomous Ultrasound Image Quality Assessment (US-IQA) is a promising tool to aid the interpretation by practicing sonographers and to enable the future robotization of ultrasound procedures. However, autonomous US-IQA has several challenges. Ultrasound images contain many spurious artifacts, such as noise due to handheld probe positioning, errors in the selection of probe parameters and patient respiration during the procedure. Further, these images are highly variable in appearance with respect to the individual patient’s physiology. We propose to use a deep Convolutional Neural Network (CNN), USQNet, which utilizes a Multi-scale and Local-to-Global Second-order Pooling (MS-L2GSoP) classifier to conduct the sonographer-like assessment of image quality. This classifier first extracts features at multiple scales to encode the inter-patient anatomical variations, similar to a sonographer’s understanding of anatomy. Then, it uses second-order pooling in the intermediate layers (local) and at the end of the network (global) to exploit the second-order statistical dependency of multi-scale structural and multi-region textural features. The L2GSoP will capture the higher-order relationships between different spatial locations and provide the seed for correlating local patches, much like a sonographer prioritizes regions across the image. We experimentally validated the USQNet for a new dataset of the human urinary bladder ultrasound images. The validation involved first with the subjective assessment by experienced radiologists’ annotation, and then with state-of-the-art CNN networks for US-IQA and its ablated counterparts. The results demonstrate that USQNet achieves a remarkable accuracy of 92.4% and outperforms the SOTA models by 3 - 14% while requiring comparable computation time.

1 October 2019
Verified
Conference Paper
Closed access
MRMasudur Rahman
Masudur Rahman
NSNatalia Sanchez-Tamayo
Natalia Sanchez-Tamayo
GGGlebys Gonzalez
Glebys Gonzalez
MAMridul Agarwal
Mridul Agarwal
Vaneet AggarwalVaneet Aggarwal
Vaneet Aggarwal
JWJuan Wachs
Juan Wachs
In the future, deployable, teleoperated surgical robots can save the lives of critically injured patients in battlefield environments. These robotic systems will need to have autonomous capabilities to take over during communication delays and unexpected environmental conditions during critical phases of the procedure. Understanding and predicting the next surgical actions (referred as “surgemes”) is essential for autonomous surgery. Most approaches for surgeme recognition cannot cope with the high variability associated with austere environments and thereby cannot “transfer” well to field robotics. We propose a methodology that uses compact image representations with kinematic features for surgeme recognition in the DESK dataset. This dataset offers samples for surgical procedures over different robotic platforms with a high variability in the setup. We performed surgeme classification in two setups: 1) No transfer, 2) Transfer from a simulated scenario to two real deployable robots. Then, the results were compared with recognition accuracies using only kinematic data with the same experimental setup. The results show that our approach improves the recognition performance over kinematic data across different domains. The proposed approach produced a transfer accuracy gain up to 20% between the simulated and the real robot, and up to 31% between the simulated robot and a different robot. A transfer accuracy gain was observed for all cases, even those already above 90%.

23 August 2024 in Electronic Materials
Verified
Journal Article
Open access
PDF file
HBHuiwen Bai
Huiwen Bai
RVRichard Voyles
Richard Voyles
RNRobert Nawrocki
Robert Nawrocki
In this work, a gate insulator poly (4-vinylphenol) (PVP) of an organic field effect transistor (OFET) was deposited using an inkjet printing technique, realized via a high printing resolution. Various parameters, including the molecular weight of PVP, printing direction, printing voltage, and drop frequency, were investigated to optimize OFET performance. Consequently, PVP with a smaller molecular weight of 11 k and a printing direction parallel to the channel, a printing voltage of 18 V, and a drop frequency of 10 kHz showed the best OFET performance. With a direct ink writing-printed organic semiconductor, this work paves the way for fully inkjet-printed OFETs.