Validation of Estimators for Weight-Bearing and Shoulder Joint Loads Using Instrumented Crutches

This research paper aimed to validate two methods for measuring loads during walking with instrumented crutches: one method to estimate partial weight-bearing on the lower limbs and another to estimate shoulder joint reactions. Currently, gait laboratories, instrumented with high-end measurement systems, are used to extract kinematic and kinetic data, but such facilities are expensive and not accessible to all patients. The proposed method uses instrumented crutches to measure ground reaction forces and does not require any motion capture devices or force platforms. The load on the lower limbs is estimated by subtracting the forces measured by the crutches from the subject’s total weight. Since the model does not consider inertia contribution in dynamic conditions, the estimation improves with low walking cadence when walking with the two-point contralateral and the three-point partial weight-bearing patterns considered for the validation tests. The shoulder joint reactions are estimated using linear regression, providing accurate values for the forces but less accurate torque estimates. The crutches data are acquired and processed in real-time, allowing for immediate feedback, and the system can be used outdoors in real-world walking conditions. The validation of this method could lead to better monitoring of partial weight-bearing and shoulder joint reactions, which could improve patient outcomes and reduce complications

Biomechanics in crutch assisted walking

Crutch-assisted walking is very common among patients with a temporary or permanent impairment affecting lower limb biomechanics. Correct crutches’ handling is the way to avoid undesired side effects in lower limbs recovery or, in chronic users, upper limbs joints diseases. Active exoskeletons for spinal cord injured patients are commonly crutch assisted. In such cases, in which upper limbs must be preserved, specific training in crutch use is mandatory. A walking test setup was prepared to monitor healthy volunteers during crunch use as a first step. Measurements were performed by using both a motion capture system and instrumented crutches measuring load distribution. In this paper, we present preliminary tests results based on different subjects - having a variety of anthropometrical characteristics - during walking with parallel or alternate crutches, the so-called three and two-points strategies. Tests results present inter and intra subject variabilities and, as a first goal, influencing factors affecting crutch loads have been identified. In the future we aim to address crutch use errors that could lead to delayed recovery or upper limbs suffering in patients, giving valuable information to physicians and therapists to improve user’s training

Validation of Contact Measurement System for Wheelchair Tennis Propulsion using Marker-less Vision System

This study investigates the reliability of marker-less vision systems for contact detection between hand and hand-rim during wheelchair propulsion. The measurement system uses a camera collecting RGB and depth images. The hand is detected through Mediapipe, a software able to recognize the key points of the hand on the RGB image. Hand position is expressed with respect to the wheel. A classifier is used to determine if there is contact between hand and hand-rim. To validate this procedure, 17 able-bodied participants pushed the wheelchair on an ergometer during six tests, given by the combinations of holding a tennis racket in their right hand while propelling at three different speeds: 4 km/h, 5.4 km/h and maximal sprint. Since validated contact detection methods are lacking in literature, experts provided a reference by manually evaluating video recordings and force signals frame-by-frame. The results showed that the hand identification by Mediapipe is not influenced by the presence of the racket but by the speed. Contact events were detected in the 99.5% of the cases. The mean error in contact time detection was -5 ms for the starts and 18 ms for the ends, the standard deviation was 48 ms for both and the combined root mean square error (RMSE) was 48 ms for the starts and 50 ms for the ends. These values, once corrected the systematic effects, lead to a standard uncertainty of approximately 0.05 s, corresponding to 15 % of the average contact duration. The study highlights the potential use of marker-less vision systems for contact detection in wheelchair propulsion

Personalized, Naturalistic Virtual Reality Scenarios Coupled With Web-Based Progressive Muscle Relaxation Training for the General Population: Protocol for a Proof-of-Principle Randomized Controlled Trial

Background: Virtual reality (VR) is an innovative tool that can facilitate exposure to either stressful or relaxing stimuli and enables individuals who have difficulties visualizing scenes to be involved in a more realistic sensorimotor experience. It also facilitates multisensory stimulation, a sense of presence, and achievement of relaxation. VR scenarios representing visual and auditory elements of natural relaxing environments can facilitate the learning of relaxation techniques such as the progressive muscle relaxation technique (PMRT). A complementary standardized technique deployed to reduce anxiety symptoms is the integration of PMRT and guided imagery (GI). Exposure to a pleasant imaginary environment helps the establishment of an association between a relaxing scenario and the relaxation technique, consequently promoting relaxation. Empirical evidence has shown that VR scenarios can increase the effects of relaxation techniques by enabling people to experience emotional conditions in more vivid settings. Objective: The main aim of this pilot study protocol is to investigate the impact on state anxiety of PMRT, associated with a personalized relaxing scenario in VR, and the role of VR scenarios in facilitating the recall of relaxing images and a sense of presence. A secondary aim is to understand if relaxing sessions administered via Zoom are more effective for managing anxiety and stress than a procedural setting based on audio-track guidance. Methods: Based on a longitudinal, between-subject design, 108 university students will be randomly exposed to one of three experimental conditions: (1) PMRT via Zoom and GI exposure, (2) PMRT via Zoom and personalized VR exposure, and (3) PMRT based on audio-track guidance and personalized VR exposure. Individuals are assessed before and after 7 training sessions based on self-report questionnaires investigating anxiety, depression, quality of life, coping strategies, sense of presence, engagement, and side effects related to VR exposure. Heart rate data are also detected by an Mi Band 2 sensor. Results: The experimental procedure is ongoing. In this paper, preliminary data from a sample of 40 participants will be illustrated. The experimental phase is expected to conclude in May 2023, and the final results of the research will be presented in June 2023. Conclusions: The results of this study will help shape the experimental design to apply it on a subsequent randomized controlled trial, also considering clinical samples. This work is expected to measure whether VR is a more engaging and helpful technique in promoting relaxation and decreasing anxiety levels than GI, by making the visualization process easier and by helping people to face more realistic sensory experiences. Assessing the efficacy of the PMRT in alternative delivery modes may extend its applications, especially in situations where the standard procedure is more challenging to be administered. To our knowledge, no equivalent study has been published so far on this matter. Trial registration: ClinicalTrials.gov NCT05478941; https://clinicaltrials.gov/ct2/show/NCT05478941. International registered report identifier (irrid): DERR1-10.2196/44183

Thyroid cartilage infiltration in advanced laryngeal cancer: prognostic implications and predictive modelling

Objective: Detection of laryngeal cartilage invasion is of great importance in staging of laryngeal squamous cell carcinoma (LSCC). The role of prognosticators in locally advanced laryngeal cancer are still widely debated. This study aimed to assess the impact of volume of thyroid cartilage infiltration, as well as other histopathologic variables, on patient survival. Materials and methods: We retrospectively analysed 74 patients affected by pT4 LSCC and treated with total laryngectomy between 2005 and 2021 at the Department of Otorhinolaryngology - Head and Neck Surgery of the University of Brescia, Italy. We considered as potential prognosticators histological grade, perineural (PNI) and lympho-vascular invasion (LVI), thyroid cartilage infiltration, and pTN staging. Pre-operative CT or MRI were analysed to quantify the volume of cartilage infiltration using 3D Slicer software. Results: The 1-, 3-, and 5-year disease free survivals (DFS) were 76%, 66%, and 64%, respectively. Using machine learning models, we found that the volume of thyroid cartilage infiltration had high correlation with DFS. Patients with a higher volume (> 670 mm3) of infiltration had a worse prognosis compared to those with a lower volume. Conclusions: Our study confirms the essential role of LVI as prognosticator in advanced LSCC and, more innovatively, highlights the volume of thyroid cartilage infiltration as another promising prognostic factor

Magnetic resonance imaging to assess cartilage invasion in recurrent laryngeal carcinoma after transoral laser microsurgery

Objective: To evaluate the diagnostic performance of magnetic resonance (MR) with surface coils in assessing cartilage invasion in recurrent laryngeal carcinoma after carbon dioxide transoral laser microsurgery (CO2 TOLMS). Methods: Two expert head and neck radiologists assessed cartilage invasion (infiltrated or non-infiltrated) in submucosal recurrences of laryngeal carcinoma after CO2 TOLMS: results were compared with histopathological report after salvage laryngectomy. Results: Thirty patients met the inclusion criteria and 90 cartilages were assessed. Overall sensitivity, specificity, and positive and negative predictive values for cartilage infiltration were 76, 93, 72 and 94%, respectively; for thyroid cartilage, the values were 82, 79, 69 and 88% respectively; for cricoid cartilage, all values were 100%; and for arytenoids, the values were 33, 96, 56 and 93% respectively. Conclusions: MR with surface coils was able to detect most thyroid and cricoid infiltration in the complex setting of post-CO2 TOLMS laryngeal carcinoma recurrence. In particular, the optimal performance in assessing cricoid invasion can be valuable in choosing the most appropriate treatment among total laryngectomy, open partial horizontal laryngectomies and non-surgical strategies

Ethmoidal arteries variability: an anatomical and radiological study

Understanding the location of ethmoidal arteries (EAs) is crucial during endo- scopic sinus surgery or skull base surgery. The aim of this study was to evaluate the anatomical variability of EAs, considering their presence and position within the ethmoid bone and their position in relation to the skull base (SB) and the frontal sinus (FS). Fourteen human heads underwent a cone-beam CT scan and an endoscopic dissection was carried out to evaluate the anatomy of the EAs. Several features were assessed both radiologically and in the lab setting: presence; position according to the “5 doors theory” (1); position respect to the SB; distance from the SB; relation with the FS (2); dehiscence of the bony canal. Anterior EA and posterior EA were present in all cases, whereas the prevalence of the middle EA was 28.57±16.73%. Anterior EA was most frequently found (64.29%) in the basal lamella of the middle turbinate; it originated from the SB in 60.71% of cases and it was separated from the FS by a single bony lamella in 46.43%. Its canal was dehiscent in 46.43±18.47%. Posterior EA was almost equally found posterior to the basal lamella of the middle turbinate, in the basal lamella of the superior turbinate and posterior to it. It was found in the SB in 82.14% of the cases and its canal was dehiscent in the 28.57±16.73%. Middle EA was found posterior to the basal lamella of the middle turbinate in 62.50% of cas- es and it was found in the SB in 75.00% of the cases. These data demonstrate that, despite their constant presence, anterior and posterior EAs showed a variable position and relationship with the SB; in addition, the data showed a non-negligible number of cases in which the middle MEA was present. Therefore, because of these several anatomical variability in EAs, a high-spatial-resolution CT should be provided for the preoperative anatomical assessment