Methods for medical applications

This paper introduces an assistive system for diagnosing malignant pleural mesothelioma (MPM), a highly aggressive cancer caused by asbestos exposure. The system assists healthcare providers in accurately determining the tumor's volume and the appropriate dose of chemotherapy to administer. It employs a bi-level process that uses machine learning and deep learning techniques to classify CT images of lungs and then calculate the tumor's volume. The study addresses the challenges associated with deep nets, such as the need for large and diverse datasets, hyperparameter optimization, and potential data bias. Two CNN architectures, Inception-v3 and ResNet-50, were compared in terms of their features and performance, and three hyperparameters were optimized for each model to generate a broad range of training scenarios. To estimate the amount of cancer cells to target, CT images were used to calculate the tumor's volume. This process involved image pre-processing, cropping volume, registering and filtering images, filling holes, segmentation, and 3D reconstruction. The results demonstrate that the developed system utilizing CNN optimizations and reconstruction of 3D images from CT images can benefit the treatment of MPM patients. The system has the potential to improve the accuracy of MPM diagnosis and the effectiveness of chemotherapy, ultimately improving patient outcomes.

Keywords: 3D volume reconstruction , CNN , CT imaging , Malignant Pleural Mesothelioma

Segmentation of anatomical components is a critical step in creating accurate and realistic 3D models of the human body, which are employed in a wide range of clinical applications, particularly in orthopedics. Recently, many deep learning approaches have been proposed to solve the problem of manual segmentation. Among the available software for automatic segmentation, MONAI Label is a free open-source tool, which allows for the creation of annotated datasets and the development of AI-based annotation models for clinical assessment. In this context, the present study is designed to compare the performance of two well-known neural networks in segmenting knee bones. In spite of the fact that several studies have investigated the use of deep learning techniques for knee reconstruction, there is no consensus regarding the most effective method. In the present study, validation metrics are selected in order to assess the accuracy of the automated segmentation models in comparison with the ground truth data. Magnetic resonance images of 31 patients have been employed for the study. As result, U-Net shows better performance than the SegResNet in the automatic femur segmentation task.

Keywords: 3D Modelling Knee , Automated Segmentation , Deep Learning , SegResNet , U-Net

When designing suspension systems for superconducting elements, the primary challenge is to strike a balance between limiting the heat load to the cold mass and ensuring the proper mechanical resistance and/or stiffness of the system. This trade-off often leads engineers to choose from a limited set of materials and supporting architectures. The aim of this study is to provide an overview of the different overall designs. Scientific articles were searched within the Google Scholar database using advanced search operators to combine a defined set of keywords. Among the architectures found, the “multi-post” solution and the “8-support” solution are the two most commonly chosen classes. Additionally, a recurrent pattern for the supporting system of superconducting cavities has been identified. The choice of architecture can be correlated with the characteristics of the superconducting element being supported, such as its mass, length, and stiffness. Furthermore, the review provides a conceptual analysis of the possibility of extending these designs to the unconventional environment of rotating machines.

Keywords: cold mass , gantry , hadrontherapy , medical machine , review , rotating machine , superconducting , supports , suspension

Background: Suicidal Behaviors and Thoughts are a relevant public health issue that includes suicidal ideation, non-suicidal self-harm, attempted suicide, and failed suicides. Since there is a progression of suicidal behaviors, whereby suicide is more likely to be completed if there have already been previous behaviors or attempts to harm oneself, WHO has highlighted the need to detect early predictors of such suicidal behaviors, which can help identify individuals at risk, plan prevention strategies and implement specific therapeutic interventions, particularly in young people, thus reducing the number of deaths. This retrospective observational study aimed to identify early predictors of suicidal risk in 237 inpatients admitted for Suicidal Behaviors and Thoughts at Child and Adolescent Psychiatry Emergency Unit of the Meyer Children's Hospital, Florence, Italy. Methods: The study was subdivided into three phases: data collection, statistical analysis, and neural network. For each patient, we collected epidemiological and psychopathological data. We stratified the inpatients into two groups: “suicidal volition patients” and “suicidal motivation patients.” Results: The hospitalization rate for suicidal behaviors and thoughts showed a growing trend from 2016 to 2020 (27.69 to 45.28%). Under 12 years of age, diagnosis of disruptive, impulse-control and conduct disorder, previous specialist care, history of attempted suicide, and intoxication as methods of suicide were statistically correlated to an increased risk of suicidal behaviors. Artificial intelligence, with an accuracy of 86.7%, confirmed these risk factors. Limitations: The most important limitation of the study is its retrospective nature. Conclusions: Our study identifies new early predictors of suicidal risk: age less than 12, diagnosis of disruptive, impulse-control and conduct disorder. In addition, suicidal volition behavior emerges as an important and underestimated risk factor. The use of artificial intelligence methods could be supporting the clinician in assessing suicidal risk.

Keywords: artificial intelligence , children and adolescents , risk of suicide and predictive factors , Suicidal behaviors and thoughts

Additive manufacturing is a technology gaining ground in fields where a high degree of product customization is required; in particular, several aspects need to be explored concerning traditional technologies, such as the variety of materials and their consumption. It also remains to be clarified whether these technologies can contribute to the ecological transition when applied in healthcare. This study compares two technologies for producing clear dental aligners: thermoforming and direct 3D printing. The former method thermoforms a polymeric disc over 3D-printed, customized models. The second, more innovative approach involves directly printing aligners using Additive Manufacturing (AM), specifically applying Digital Light Processing (DLP) technology. The study conducts a comparative Life Cycle Assessment (LCA) analysis to assess the environmental impact of these two different manufacturing processes. The research results highlight that adopting direct printing through AM can bring advantages in terms of environmental sustainability, thanks to the reduction in raw materials and electricity consumption. These drops are drivers for the decreased potential environmental impacts across all impact categories considered within the EF 3.1 method. Furthermore, lowering the amount of raw material needed in the direct printing process contributes to a notable decrease in the overall volume of waste generated, emphasizing the environmental benefits of this technique.

Keywords: additive manufacturing , healthcare , life cycle assessment , sustainability

Background: Osteoporosis can reduce bone quality and increase the risk of fractures. In addition to pharmacological approaches, physical activity, and implanted devices, external devices can also be detected in the literature as a technique to strengthen bones. This type of intervention arises to be particularly promising because it minimizes the invasiveness of therapy. Methods: A systematic review of the technologies involved in such devices was carried out to identify the most fruitful ones in improving bone quality. This review, according to the PRISMA Statement, focuses on studies involving animals, and excludes pharmaceutical approaches. Findings: The animal models and devices used, their settings, interventions, outcomes measured, and consequent effect on bone quality are reported for each detected technology. Ultrasound and laser arose to be the most studied technologies in the literature, even if they have yet to be proved to have a significant effect on bone quality. Interpretation: External devices for bone quality improvement offer a non-invasive approach that causes minimum discomfort to the patient. This review aimed to detect which technologies reported in the literature significantly affect bone quality. The results showed that several technologies are currently used to improve bone quality. However, each study measures different outcomes and uses different measurement methods, device settings, and interventions. This lack of standardization and the reduced number of articles found do not allow for proper quantitative comparisons.

Keywords: Bone quality , External devices , Non-invasive approach , Osteoporosis

In orthopedic medical devices, differences in elasto-plastic behavior between bone and metallic materials could lead to mechanical issues at the bone-implant interface, such as stress shielding, bone fracture or implant failure. To reduce mismatching-related adverse events between bone and prosthetic mechanical properties, an in-body geometry optimization could be the right approach to reduce prosthetic stiffness. Therefore, this study aims to assess the elastic behavior of four different in-body gap prismatic geometries (quadratic, hexagonal, octagonal, and circular) and how much they reduce bulk stiffness. Uniaxial compression tests were performed on five cubes with a 20 mm thickness, each containing a different set of internal prismatic gaps. For each design, the elastic response was calculated and compared with a full-volume cube, used as control. All cubes showed a stiffness reduction compared to the control, greater in cubes with quadratic (21%), octagonal (18%), and circular (17%) transversal sections, compared to the hexagonal one (6%). Moreover, finite element models were implemented and tested, showing coherent values obtained through the experimental tests. In addition, a bi-material approach was studied in silico and the results suggested that variable elastic behavior could be obtained by using composite material, providing lower mechanical properties than commonly used commercial prosthetic materials.

Keywords: compression tests , experimental tests , finite element analysis , in-body gaps , Material stiffness , validation

The aim of the present case report was to provide a longitudinal functional assessment of a patient with transfemoral amputation from the preoperative status with socket-type prosthesis to one year after the osseointegration surgery. A 44 years-old male patient was scheduled for osseointegration surgery 17 years after transfemoral amputation. Gait analysis was performed through 15 wearable inertial sensors (MTw Awinda, Xsens) before surgery (patient wearing his standard socket-type prosthesis) and at 3-, 6-, and 12-month follow-ups after osseointegration. ANOVA in Statistical Parametric Mapping was used to assess the changes in amputee and sound limb hip and pelvis kinematics. The gait symmetry index progressively improved from the pre-op with socket-type (1.14) to the last follow-up (1.04). Step width after osseointegration surgery was half of the pre-op. Hip flexion-extension range significantly improved at follow-ups while frontal and transverse plane rotations decreased (p < 0.001). Pelvis anteversion, obliquity, and rotation also decreased over time (p < 0.001). Spatiotemporal and gait kinematics improved after osseointegration surgery. One year after surgery, symmetry indices were close to non-pathological gait and gait compensation was sensibly decreased. From a functional point of view, osseointegration surgery could be a valid solution in patients with transfemoral amputation facing issues with traditional socket-type prosthesis.

Keywords: biomechanics , case report , gait analysis , gait symmetry , osseointegration , socket-type , transfemoral amputation , wearable sensors

Typically, samples for PCR instruments are prepared manually by trained laboratory personnel, which in this case refers to the sample preparation, the dispensing of a master mix and a biological sample with subsequent mixing. To reduce the workload, there are approaches towards fully automated PCR systems, but in most cases only proprietary thermal cyclers can be used. Other approaches involve a similarly complex robotic solution. In this work, the spectrum was extended by a method that can be integrated into the workflow of existing PCR protocols. For this purpose, a user-friendly solution using a microfluidic chip was developed. For the sample preparation different mixing concepts were selected as well as a concept for aliquoting. Optimization and evaluation were assisted by utilization of simulations to study system behavior. The systems consisting of a mixer and a flow splitter were manufactured by milling. Subsequently, the mixing and aliquoting capability of the system could be investigated in the laboratory assembly. The testing of this prototype showed moderate results which are attributed to the accuracy of the laboratory assembly.

Keywords: Fluid Dosing , Microfluidic , PCR , Simulation , Subtractive Manufacturing

This work briefly discusses the applications of Layered Double Hydroxides (LDHs) to medicine and presents a study regarding the growth of LDHs on the biodegradable AZ31 alloy foreseen to manufacture a rib-fixator. Mg is one of the most investigated metallic materials for biomedical applications owing to its high biocompatibility and osteointegration, as well as a value of the elastic modulus close to that of human bone. Since Mg is essential for metabolism, when it degrades forming Mg2+ ions, it promotes healing and growth of bone tissue. Experiments have been carried out to grow LDHs on the alloy surface in view to retard corrosion in human body and intercalate drugs to be released in-situ, with anti-inflammatory, analgesic, and antimicrobial action.

Keywords: AZ31 , Biomedical Applications , Layered Double Hydroxides , Mg alloys , Rib-fixator

Prototypes are an excellent tool to actualize an idea or a concept. As reported by different methodologies (Double Diamond, Design Thinking), prototypes enable designers to quickly iterate and learn from their designs. Their advantages are not limited to this aspect: by iteratively increasing the level of complexity from one version of the prototype to the next one, they can help enhance the skill set of a person through a learning-by-doing approach. This iterative process allows for the identification of unknown unknowns and can lead to the development of innovative solutions in various contexts, including biomedical engineering and rehabilitation. The multiple iterations and learning processes, inherent in the rehabilitation phase are a great asset when facing biomedical projects, which require multidisciplinary knowledge. The purpose of this paper is to provide supporting evidence for the importance of prototypes in biomedical design as tools to fill the skill gap, by presenting a real-world case study performed in an academic context. A team of university students developed a novel solution for post-stroke rehabilitation, DEUHR (Digital Exergame for Upper Limb and Hand Rehabilitation), based on innovative trends in biomedical technologies, such as motion tracking sensors and exergames. The paper reports the entire process for the design of the rehabilitation system, starting from the initial concept, prototypes, tests with the users, and final outcomes. The concept for DEUHR was first developed through a series of brainstorming sessions and analysis of existing rehabilitation solutions. The team then moved on to creating low-fidelity prototypes to test and refine the interaction design and gameplay mechanics of the exergame. These low-fidelity prototypes allowed the team to quickly iterate and gather feedback from potential users, including stroke patients and rehabilitation therapists. Based on the feedback received, the team made several iterations and improvements to the prototype, gradually increasing the level of complexity and fidelity. This iterative process of prototype development allowed the authors to improve the functionality and usability of DEUHR. To evaluate the usability and effectiveness of DEUHR, a high-fidelity prototype was created in the form of a tablet-based exergame for training. New tests with both the high-fidelity prototype connected with the wearable device were made with users in order to test the functionality and usability altogether. This paper outcome consisted of a demonstrator merging the three main components of the project (the exergame, the sensing unit, and the app) which were later tested on patients. Even if the case study concerned the design of health monitoring devices, it provided valuable insights with respect to the UX design process and allowed the team to grow and expand their initial skill set to meet the requirements needed. This experience led to a rethinking of the prototyping process as an enhancing and engaging opportunity to be featured in a learning environment – possibly extending its validity also outside of the biomedical field.

Keywords: Design thinking , Prototypes , Telerehabilitation , Wearable device

More than ever, precision surgery is making its way into modern surgery for functional organ preservation. This is possible mainly due to the increasing number of technologies available, including 3D models, virtual reality, augmented reality, and artificial intelligence. Intraoperative surgical navigation represents an interesting application of these technologies, allowing to understand in detail the surgical anatomy, planning a patient-tailored approach. Automatic superimposition comes into this context to optimally perform surgery as accurately as possible. Through a dedicated software (the first version) called iKidney, it is possible to superimpose the images using 3D models and live endoscopic images during partial nephrectomy, targeting the renal mass only. The patient is 31 years old with a 28 mm totally endophytic right-sided renal mass, with a PADUA score of 9. Thanks to the automatic superimposition and selective clamping, an enucleoresection of the renal mass alone was performed with no major postoperative complication (i.e., Clavien–Dindo < 2). iKidney-guided partial nephrectomy is safe, feasible, and yields excellent results in terms of organ preservation and functional outcomes. Further validation studies are needed to improve the prototype software, particularly to improve the rotational axes and avoid human help. Furthermore, it is important to reduce the costs associated with these technologies to increase its use in smaller hospitals.

Keywords: 3D models , artificial intelligence , augmented reality , kidney cancer , robotics

Objective: To evaluate the accuracy of our new three-dimensional (3D) automatic augmented reality (AAR) system guided by artificial intelligence in the identification of tumour's location at the level of the preserved neurovascular bundle (NVB) at the end of the extirpative phase of nerve-sparing robot-assisted radical prostatectomy. Methods: In this prospective study, we enrolled patients with prostate cancer (clinical stages cT1c–3, cN0, and cM0) with a positive index lesion at target biopsy, suspicious for capsular contact or extracapsular extension at preoperative multiparametric magnetic resonance imaging. Patients underwent robot-assisted radical prostatectomy at San Luigi Gonzaga Hospital (Orbassano, Turin, Italy), from December 2020 to December 2021. At the end of extirpative phase, thanks to our new AAR artificial intelligence driven system, the virtual prostate 3D model allowed to identify the tumour's location at the level of the preserved NVB and to perform a selective excisional biopsy, sparing the remaining portion of the bundle. Perioperative and postoperative data were evaluated, especially focusing on the positive surgical margin (PSM) rates, potency, continence recovery, and biochemical recurrence. Results: Thirty-four patients were enrolled. In 15 (44.1%) cases, the target lesion was in contact with the prostatic capsule at multiparametric magnetic resonance imaging (Wheeler grade L2) while in 19 (55.9%) cases extracapsular extension was detected (Wheeler grade L3). 3D AAR guided biopsies were negative in all pathological tumour stage 2 (pT2) patients while they revealed the presence of cancer in 14 cases in the pT3 cohort (14/16; 87.5%). PSM rates were 0% and 7.1% in the pathological stages pT2 and pT3 (<3 mm, Gleason score 3), respectively. Conclusion: With the proposed 3D AAR system, it is possible to correctly identify the lesion's location on the NVB in 87.5% of pT3 patients and perform a 3D-guided tailored nerve-sparing even in locally advanced diseases, without compromising the oncological safety in terms of PSM rates.

Keywords: Artificial intelligence , Augmented reality , Prostate cancer , Radical prostatectomy , Robotics

Periprosthetic joint infections (PJIs) still remain a severe complication after arthroplasty despite the significant advances in manufacturing materials in the orthopaedic field. The sol–gel based coating strategy is attracting interest for its multifaceted potential to design surfaces capable of exerting antibacterial properties. In this study, the sol–gel technique is employed to obtain a new class of titanium dioxide coatings doped with silver and gallium ions to minimize the adhesion and bacterial colonization on the CoCrMo surfaces. Uniform anatase titania coatings with hydrophobic behaviour and nanometer thickness (50–200 nm) were obtained by dipping CoCrMo samples in TiO2 sols with different compositions. The physicochemical characterization of coatings using EDS, GDOES, and ICP-OES confirmed the incorporation of doping agents. Antimicrobial assays were performed against Gram-positive S. aureus and Gram-negative E. coli bacteria, demonstrating a satisfying antibacterial activity. Furthermore, all the coatings tested showed no cytotoxicity and osteodifferentiation potential. Thus, the herein sol–gel strategy could represent a powerful tool for surface modification of CoCrMo-based materials for implantable devices.

Keywords: Antibacterial coatings , CoCrMo alloys , Gallium , Silver , Titanium dioxide

This study evaluated the influence of distal implants angulation and framework material in the stress concentration of an All-on-4 full-arch prosthesis. A full-arch implant-supported prosthesis 3D model was created with different distal implant angulations and cantilever arms (30° with 10-mm cantilever; 45° with 10-mm cantilever and 45° with 6-mm cantilever) and framework materials (Cobalt–chrome [CoCr alloy], Yttria-stabilized tetragonal zirconia polycrystal [Y-TZP] and polyetheretherketone [PEEK]). Each solid was imported to computer-aided engineering software, and tetrahedral elements formed the mesh. Material properties were assigned to each solid with isotropic and homogeneous behavior. The contacts were considered bonded. A vertical load of 200 N was applied in the distal region of the cantilever arm, and stress was evaluated in Von Misses (σVM) for prosthesis components and the Maximum (σMAX) and Minimum (σMIN) Principal Stresses for the bone. Distal implants angled in 45° with a 10-mm cantilever arm showed the highest stress concentration for all structures with higher stress magnitudes when the PEEK framework was considered. However, distal implants angled in 45° with a 6-mm cantilever arm showed promising mechanical responses with the lowest stress peaks. For the All-on-4 concept, a 45° distal implants angulation is only beneficial if it is possible to reduce the cantilever's length; otherwise, the use of 30° should be considered. Comparing with PEEK, the YTZP and CoCr concentrated stress in the framework structure, reducing the stress in the prosthetic screw.

Keywords: Dental implants , Finite element analysis , Polymers , Prosthodontics

In this paper, we present a biomechanical analysis of the upper body, which includes upper-limb, neck and trunk, during the execution of overhead industrial tasks. The analysis is based on multiple performance metrics obtained from a biomechanical analysis of the worker during the execution of a specific task, i.e. an overhead drilling task, performed at different working heights. The analysis enables a full description of human movement and internal load state during the execution of the task, thought the evaluation of joint angles, joint torques and muscle activations. A digital human model is used to simulate and replicate the worker's task in a virtual environment. The experiments were conduced in laboratory setting, where four subjects, with different anthropometric characteristics, have performed 48 drilling tasks in two different working heights defined as low configuration and middle configuration. The results of analysis have impact on providing the best configuration of the worker within the industrial workplace and/or providing guidelines for developing assistance devices which can reduce the physical overloading acting on the worker's body.

Keywords: Biomechanics , Digital human models , Electromyography , Ergonomics , Industry , Overhead tasks

The presented work shows how a user centered approach might be used to generate and select the optimal design of smart garments for biosignal acquisition. Design is driven by human biosignal analysis, allowing the translation of subjective user's feelings into technical specification and the definition of customized criteria for concepts evaluation. So, different concepts are generated and, involving users again, the optimal one is chosen using multi criteria decision making based on Fuzzy AHP theory. A case study on a wearable system (i.e., electromyographic shorts) for football performance and risk injury analysis is shown.

Keywords: Biological knowledge in engineering science , User centered design , Wearable technologies

In this study we propose a brief analysis of recent soft wearable robots for upper–limb which could have a major impact on future developments and applications. The systems are analysed with respect to: design concepts, actuation systems, sensing systems, control strategies and applications. Finally, a discussion and open issues are presented.

Keywords: Exoskeletons , Soft robotics , Wearable robotics

In this work we derive the requirements of a soft upper-limb exoskeletons starting from the biomechanical analysis of human workers while performing three different industrial overhead tasks in laboratory settings. The results of the work allow to define the degrees of freedom which need to be supported to reduce the biomechanical overloads, as well the dimensional characteristics, in terms of required lengths and forces, of the soft actuators of the wearable robot.

Keywords: Biomechanics , Design , Industrial tasks , Soft exoskeleton , Soft robotics , Wearable robotics

Background and objective: In orthopedic medical devices, elasto-plastic behavior differences between bone and metallic materials could lead to mechanical issues at the bone-implant interface, as stress shielding. Those issue are mainly related to knee and hip arthroplasty, and they could be responsible for implant failure. To reduce mismatching-related adverse events between bone and prosthesis mechanical properties, modifying the implant's internal geometry varying the bulk stiffness and density could be the right approach. Therefore, this feasibility study aims to assess which in-body gap geometry improves, by reducing, the bulk stiffness. Methods: Using five finite element models, a uniaxial compression test in five cubes with a 20 mm thickness was simulated and analyzed. The displacements, strain and Young Modulus were calculated in four cubes, each containing internal prismatic gaps with different transversal sections (squared, hexagonal, octagonal, and circular). Those were compared with a fifth full-volume cube used as control. Results: The most significant difference have been achieved in displacement values, in cubes containing internal gaps with hexagonal and circular transversal sections (82 µm and 82.5 µm, respectively), when compared to the full-volume cube (69.3 µm). Conclusions: This study suggests that hexagonal and circular shape of the gaps allows obtaining the lower rigidity in a size range of 4 mm, offering a starting approach to achieve a “close-to-bone” material, with a potential use in prosthetic devices with limited thickness.

Keywords: Finite element analysis , In-body gaps , Material stiffness