GUFFANTI MARTÍNEZ, DIEGO ANDRES

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Main Affiliation

Facultad de Ciencias de la Ingeniería e Industrias

GISER - Grupo de Investigación en Sistemas Embebidos y Robótica

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ORCID

0000-0002-1244-291X

Scopus Author ID

57200385407

Now showing 1 - 10 of 21

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Supervised learning for improving the accuracy of robot-mounted 3D camera applied to human gait analysis
(Elsevier BV, 2024-02)
GUFFANTI MARTINEZ, DIEGO ANDRES
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Alberto Brunete
;
Miguel Hernando
;
David Álvarez
;
Javier Rueda
Background and Objective: the use of 3D cameras for gait analysis has been highly questioned due to the low accuracy they have demonstrated in the past. The objective of the study presented in this paper is to improve the accuracy of the estimations made by robot-mounted 3D cameras in human gait analysis by applying a supervised learning stage. Methods: the 3D camera was mounted in a mobile robot to obtain a longer walking distance. This study shows an improvement in detection of kinematic gait signals and gait descriptors by post-processing the raw estimations of the camera using artificial neural networks trained with the data obtained from a certified Vicon system. To achieve this, 37 healthy participants were recruited and data of 207 gait sequences were collected using an Orbbec Astra 3D camera. There are two basic possible approaches for training and both have been studied in order to see which one achieves a better result. The artificial neural network can be trained either to obtain more accurate kinematic gait signals or to improve the gait descriptors obtained after initial processing. The former seeks to improve the waveforms of kinematic gait signals by reducing the error and increasing the correlation with respect to the Vicon system. The second is a more direct approach, focusing on training the artificial neural networks using gait descriptors directly. Results: the accuracy of the 3D camera to objectify human gait was measured before and after training. In both training approaches, a considerable improvement was observed. Kinematic gait signals showed lower errors and higher correlations with respect to the ground truth. The accuracy of the system to detect gait descriptors also showed a substantial improvement, mostly for kinematic descriptors rather than spatio-temporal. When comparing both training approaches, it was not possible to define which was the absolute best. Conclusions: supervised learning improves the accuracy of 3D cameras but the selection of the training approach will depend on the purpose of the study to be conducted. This study reveals the great potential of 3D cameras and encourages the research community to continue exploring their use in gait analysis.
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Technological Advancements in Human Navigation for the Visually Impaired: A Systematic Review
(MDPI AG, 2025-04-01)
Edgar Casanova
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GUFFANTI MARTINEZ, DIEGO ANDRES
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HIDALGO AGUILERA, LUIS ARMANDO
Visually impaired people face significant obstacles when navigating complex environments. However, recent technological advances have greatly improved the functionality of navigation systems tailored to their needs. The objective of this research is to evaluate the effectiveness and functionality these navigation systems through a comparative analysis of recent technologies. For this purpose, the PRISMA 2020 methodology was used to perform a systematic literature review. After identification and screening, 58 articles published between 2019 and 2024 were selected from three academic databases: Dimensions (26 articles), Web of Science (18 articles), and Scopus (14 articles). Bibliometric analysis demonstrated a growing interest of the research community in the topic, with an average of 4.552 citations per published article. Even with the technological advances that have occurred in recent times, there is still a significant gap in the support systems for people with blindness due to the lack of digital accessibility and the scarcity of adapted support systems. This situation limits the autonomy and inclusion of people with blindness, so the need to continue developing technological and social solutions to ensure equal opportunities and full participation in society is evident. This study emphasizes the great advances with the integration of sensors such as high-precision GPS, ultrasonic sensors, Bluetooth, and various assistance apps for object recognition, obstacle detection, and trajectory generation, as well as haptic systems, which provide tactile information through wearables or actuators and improve spatial awareness. Current navigation algorithms were also identified in the review with methods including obstacle detection, path planning, and trajectory prediction, applied to technologies such as ultrasonic sensors, RGB-D cameras, and LiDAR for indoor navigation, as well as stereo cameras and GPS for outdoor navigation. It was also found that AI systems employ deep learning and neural networks to optimize both navigation accuracy and energy efficiency. Finally, analysis revealed that 79% of the 58 reviewed articles included experimental validation, 87% of which were on haptic systems and 40% on smartphones. These results underscore the importance of experimentation in the development of technologies for the mobility of people with visual impairment.
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Continuous Speech Recognition and Identification of the Speaker System
(Springer International Publishing, 2018)
GUFFANTI MARTINEZ, DIEGO ANDRES
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Danilo Martínez
;
José Paladines
;
Andrea Sarmiento
Currently speech recognition and speaker identification based on a biometric parameter such as voice have been treated as two different worlds and in the market there are no integrated applications of these systems. The design of a system could mean a great contribution to the development of personalized commands, in the area of home automation and robotics, thanks to the availability of the message and the identification of the speaker. Therefore, the development of an integrated biometric voice system is proposed, based on a single voice sample for the identification of the speaker and the message. We use GOOGLE SPEECH API, as a voice text translation tool, and Mel Frequency Cepstral Coefficients or MFCCs extracted from voice signal to identify speakers voice. Functional tests were carried with 50 randomly users, in the end of the study results show 96.4% efficiency in identification, demonstrating efficiency using MFCCs in speaker’s automatic recognition and verifying the use of GOOGLE SPEECH API as a fast, accurate and robust translation tool.
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Organic zinc sources in broiler production at high altitude under on-top supplementation or total or partial replacement: 1. Effects on performance and zinc excretion
(Elsevier BV, 2024-12)
R. Riboty
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J.L. Gaibor
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C.L. Ponce-de-Leon
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GUFFANTI MARTINEZ, DIEGO ANDRES
Feeding broilers with organic chemical sources of Zn has recently been recommended to improve performance, immune system, carcass yield, and reduce environmental contamination. However, its use under proposed supplementation strategies (i.e., total replacement, partial replacement, on-top) needs further investigation. This study assessed the effect of total replacement, partial replacement, and on-top supplementation strategies to feed organic Zn sources and the effect of two organic chemical forms on performance and Zn excretion in broilers at high altitudes. Twenty-two male Cobb 500-day-old chicks were placed in each of 54 floor pens and raised for up to 42 days under a three-phase feeding program and following the Ecuadorian highland production system. Pens were assigned to one of nine experimental treatments consisting of a basal diet supplemented with 0, 33, and 100 ppm of Zn from ZnSO4 and added or not 40 ppm Zn from Zn proteinate or Zn amino acid complex. A Completely Randomized Block Design was considered, being the block the replication. The Zn concentration of the basal diet was determined. Feed intake, BW, BW gain, feed conversion ratio, and European Production Efficiency Factor were assessed at 21 and 42 days of age, and the Zn excretion was estimated accordingly. Each supplementation strategy was compared with the standard practice (100 ppm Zn as ZnSO4) using contrasts and mixed models, and the interaction with the chemical form was assessed considering the P-values of the ANOVA and the multiple comparisons between the corresponding treatments. The effects of the organic Zn forms and their interactions with the dietary Zn level were assessed considering the responses were linear functions of the organic Zn source, the feed intake, the Zn intake, the Zn supplementation level, and the block, as corresponding. None of the strategies to supplement a Zn organic source, or the organic sources themselves, showed overall detectable effects on performance. However, interactions were observed between the supplementation strategy and the organic Zn source and between the organic source and the dietary Zn levels or the Zn intake. Under the on-top supplementation strategy, the Zn organic sources showed different feed conversion ratios at 21 days. In addition, totally or partially replacing the ZnSO4 with a Zn organic form reduced the Zn excretion. In conclusion, although no overall effect of the supplementation strategies was detected, the assessed organic Zn forms showed different effects on the feed conversion ratio at 21 days.
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Organic zinc sources in broiler production at high altitude under on-top supplementation or total or partial replacement: 2. Effects on tibia and blood characteristics
(Elsevier BV, 2024-12)
R. Riboty
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J.L. Gaibor
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C.L. Ponce-de-Leon
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GUFFANTI MARTINEZ, DIEGO ANDRES
The use of organic Zn sources has been claimed to reduce the environmental impact of poultry production and improve broiler performance and the quality of products. This study investigated the effects of three organic Zn supplementation strategies (i.e., TRE, total replacement; PRE, partial replacement; OTS, on-top supplementation) on tibia and blood biochemistry characteristics of broilers at high altitudes. Male Cobb 500 chicks were distributed in 54 floor pens (22 birds each) and assigned to nine experimental treatments. Birds were fed mash diets under three feeding phases until 42 days and following the standard Ecuadorian high-altitude production standard practices. The treatments were a basal diet supplemented with three inclusion rates of ZnSO4 and the same diets including or not Zn from one of two organic Zn sources (i.e., ZPR, Zn proteinate; ZAC, Zn amino acid complex). Basal diets were analyzed for Zn concentration. Tibia ash and Zn concentrations and serum biochemistry variables were determined at 21 and 42 days. The strategies to supplement organic Zn were compared with the reference treatment containing 100 ppm Zn as ZnSO4 (the standard practice; STD) using mixed models, being the block (i.e., the replication) as a random factor. The interaction of the strategy with the organic Zn source was assessed with the ANOVA and multiple comparisons. The organic Zn sources were compared considering the feed intake a random factor, and their interaction with the dietary Zn level was assessed using multiple regression. No overall effect of the Zn supplementation strategy was observed other than the reduced Zn concentration at 21 days in TRE birds. At 21 days, PRE and TRE increased the serum protein and phosphorus concentrations, respectively. At that age, TRE also increased insulin concentration, but only in the ZAC-fed birds. However, TRE produced the opposite effect on serum protein at 42 days. At the same age, ZAC-fed birds showed lower serum phosphorus concentration than ZPR-fed ones regardless of the dietary Zn supplementation level or the Zn intake. Also, ZAC under TRE produced no effect on tibia Zn concentration compared to STD, but ZPR increased it. The ZPR increased the tibia Zn concentration when fed under PRE or TRE, but not under OTS. In conclusion, the results showed no adverse effect of PRE or TRE strategies on tibia characteristics. The data indicate likely different effects of PRE and TRE on protein metabolism and a possible negative interaction of the organic Zn with a high Zn content as ZnSO4.
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Comparison of Two System Identification Approaches for a Four-Wheel Differential Robot Based on Velocity Command Execution
(MDPI AG, 2025-06-05)
GUFFANTI MARTINEZ, DIEGO ANDRES
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Moisés Filiberto Mora Murillo
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Marco Alejandro Hinojosa
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Santiago Bustamante Sanchez
;
Javier Oswaldo Obregón Gutiérrez
Precise modeling of differential drive robots is crucial for effective control and trajectory planning in autonomous systems. A comparative analysis of two modeling approaches for a four-wheel differential drive robot is presented in this paper. The first approach, named Motor-Based Model (MBM), identifies four transfer functions, one for each motor, while the second approach, named Simplified Model (SM), uses only two transfer functions, one for linear velocity and another for angular velocity. Both models were validated by comparing their predicted trajectories against real odometry data obtained from a SLAM system implemented on a differential-drive robot. This provided a practical assessment of each model’s accuracy and underscored the importance of model selection in control design and navigation tasks. The results showed that the Motor-Based Model (MBM) consistently outperformed the Simplified Model (SM) in terms of odometry accuracy, both in position and orientation. Across all trajectories, the average RMSE for position using MBM was 0.309 m, while the SM recorded a higher average RMSE of 0.414 m. Similarly, the maximum position error averaged 0.522 m for MBM and 0.710 m for SM, confirming that MBM is more accurate and consistent in position tracking. Regarding the results of orientation estimation, when averaged across all experiments, the MBM maintained a lower angular RMSE of 0.170 rad in contrast to SM, which achieves an RMSE of 0.239 rad. The maximum angular error was also higher for the MBM at 0.316 rad, compared to 0.447 rad for the SM. Moreover, the computational performance evaluation indicated that the SM consistently outperformed MBM, achieving a 30% reduction in simulation time and substantially lower memory usage. These results demonstrate the relationship between model complexity and accuracy and suggest that the motor-specific model is more appropriate for applications requiring precise mapping or localization, such as SLAM, while the simplified model may be suitable for simpler use cases with lower computational requirements, such as embedded systems with limited resources. This paper provides a practical evaluation of the accuracy and computational performance of two modeling approaches, highlighting the implications of model selection for the design of navigation tasks.
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Non-Invasive Multi-Camera Gait Analysis System and its Application to Gender Classification
(Institute of Electrical and Electronics Engineers (IEEE), 2020)
GUFFANTI MARTINEZ, DIEGO ANDRES
;
Alberto Brunete
;
Miguel Hernando
Objective: Most studies have conducted human gait analysis using expensive and invasive photogrammetric systems. The objective of this study was to demonstrate that non-invasive and cost-effective systems based on depth cameras may be able to retrieve relevant features of human gait patterns. We aimed to prove this by solving the problem of gait classification by gender. Methods: 81 participants (40 female and 41 male) walked at a self-selected speed across a 4.8-meter walkway. Gait data was recorded using multiple depth sensors. Analysis in time domain included joint excursions by gait phases, range of movement (ROM), central tendency and dispersion measures, spatial variables, and center of mass (COM) position. The spectral analysis included principal frequency, magnitude, and phase shift during walking. Only features with significant differences by gender were used to train a support vector machine (SVM) classifier. Results: A total of 108 features presented significant differences by gender (p<; 0.05). On this basis, the accuracy of the chosen model was 96.7%. Trunk rotation, trunk sway, knee abduction/adduction, and pelvic obliquity were the most differentiated between the groups. The COM position shown a significant difference by gender (p=0.0065) with 51.7% and 51.0% for men and women respectively. Women proved to have significantly shorter normalized step width than men (p=0.0472). Conclusion: The proposed method was able to retrieve most of human gait features correctly, including differences in gait pattern by gender. Significance: Depth cameras represent a cost-effective system that could be used for a deeper biomechanical human gait analysis.
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Human Gait Analysis Using Non-invasive Methods with a ROS-Based Mobile Robotic Platform
(Springer International Publishing, 2020-11-10)
GUFFANTI MARTINEZ, DIEGO ANDRES
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Alberto Brunete
;
Miguel Hernando Gutierrez
Mobile robotic platforms for human gait analysis could open the gap to multiple medical applications and new discoveries. They could take several advantages over certified photogrammetric systems by making possible gait analysis without space limitations. In this document we present the design of a new ROS-based mobile robot platform for human gait analysis. All processes are ROS-based and Nuitrack SDK is used to develop the skeleton tracking application with a depth camera. During the procedure we described the design of the control law implemented for gait analysis. We developed a lead compensator by root locus method to increase the stability and speed response of the system. The error of measurement with respect to a certified photogrammetric system was considerably low during positioning task. Additional measurements were performed to verify the acquisition of gait parameters. These included spatio-temporal variables and range of movement (ROM) of knee and hip during joint excursions. Results showed that this mobile robotic platform represents a non-invasive alternative that could be improved for use in biomechanical human gait analysis.
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Mechatronic Design of a Self-Contained Dexterous Robotic Hand for Gestural Communication
(Springer Science and Business Media LLC, 2023-01-13)
Miguel Hernando
;
Carlos Morillo
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GUFFANTI MARTINEZ, DIEGO ANDRES
;
Alberto Brunete
The hand is the most representative tool of the human body because of its complexity, dexterity, and precision. The high amount of both electronic and mechanical components results in a very difficult integration of all components inside the hand. The main objective of this work is to develop a fully integrated gestural robotic hand based on new design concepts that combine mechanics and electronics to provide a solution to the problem of limited space. ManoPla is a gestural hand, so its naturalness, low weight and full integration are the main design requirements. In this way, mechanisms that allow joint mobility have been developed using elastic components. The Color Gradient Method was applied to feed back the position of the joints. In addition, a novel thumb design with 4 degrees of freedom has been developed, including an advanced trapezium design. The Cutkosky grasp taxonomy was successfully reproduced to demonstrate the mobility of the hand proposed in this study. An impact test demonstrated the flexibility of the joints thanks to the SEA actuation approach. The main contributions of this paper are new design concepts to integrate mechanics and electronics inside the hand. In this way, ManoPla can easily be included as a gestural module of a humanoid robot for social interaction.
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Development and validation of a ROS-based mobile robotic platform for human gait analysis applications
(Elsevier BV, 2021-11)
GUFFANTI MARTINEZ, DIEGO ANDRES
;
Alberto Brunete
;
Miguel Hernando
Background: The integration of mobile robotic platforms in human gait analysis offers the potential to develop multiple medical applications and achieve new discoveries. The aim of this paper is to present a first design and validation of a ROS-based mobile robotic platform for human gait analysis. Methods: During the design stage, the model identification and the configuration of the control law were performed. The design of the control law required the integration of a lead compensator and a Filtered Smith Predictor (FSP). During the validation procedure, the accuracy of the system to retrieve kinematic gait data and the main descriptors of gait disorders was calculated with respect to the ground truth of a Vicon system. For this purpose, one hundred gait recordings were processed thanks to the collaboration of twenty participants. The participants walked in a one-way straight line gait. Results: Results showed high correlation and low error rates mainly in joint excursions from sagittal and transverse planes. Conclusion: This gait analysis system demonstrated several advantages compared with the current approaches. The use of a mobile robotic platform allowed gait analysis in long tracking ranges and without space limitations. Furthermore, the design of a suitable control law allowed a smooth tracking of the person. This led to optimal results when assessing joint excursions. Significance: This system represents a cost-effective and non-invasive alternative that could be used for human gait analysis applications.

GUFFANTI MARTÍNEZ, DIEGO ANDRES

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