Chest Wall Motion Research Articles

Overdose Detection Among High-Risk Opioid Users Via a Wearable Chest Sensor in a Supervised Injecting Facility: Protocol for an Observational Study.

Opioid overdose is a global health crisis, affecting over 27 million individuals worldwide, with more than 100,000 drug overdose deaths in the United States in 2022-2023. This protocol outlines the development of the PneumoWave chest biosensor, a wearable device being designed to detect respiratory depression in real time through chest motion measurement, intending to enhance early intervention and thereby reduce fatalities. The study aims to (1) differentiate opioid-induced respiratory depression (OIRD) from nonfatal opioid use patterns to develop and refine an overdose detection algorithm and (2) examine participants' acceptability of the chest biosensor. The study adopts an observational design over a 6-month period. The biosensor, a small device, will be worn by consenting participants during injecting events to capture chest motion data. Safe injecting facilities (SIF) in Melbourne, Victoria (site 1), and Sydney, New South Wales (site 2), which are legally sanctioned spaces where individuals can use preobtained illicit drugs under medical supervision. Each site is anticipated to recruit up to 100 participants who inject opioids and attend the SIF. Participants will wear the biosensor during supervised injecting events at both sites. The biosensor will attempt to capture data on an anticipated 40 adverse drug events. The biosensor's ability to detect OIRD will be compared to the staff-identified events that use standard protocols for managing overdoses. Measurements will include (1) chest wall movement measured by the biosensor, securely streamed to a cloud, and analyzed to refine an overdose detection algorithm and (2) acute events or potential overdose identified by site staff. Acceptability will be measured by a feedback questionnaire as many times as the participant is willing to throughout the study. As of April 2024, a total of 47 participants have been enrolled and data from 1145 injecting events have already been collected, including 10 overdose events. This consists of 17 females and 30 males with an average age of 45 years. Data analysis is ongoing. This protocol establishes a foundation for advancing wearable technology in opioid overdose prevention within SIFs. The study will provide chest wall movement data and associated overdose data that will be used to train an algorithm that allows the biosensor to detect an overdose. The study will contribute crucial insights into OIRD, emphasizing the biosensor's potential step forward in real-time intervention strategies. DERR1-10.2196/57367.

Bioengineering Approaches and Novel Biomaterials to Enhance Sternal Wound Healing after Cardiac Surgery: A Crosstalk between Innovation and Surgical Practice.

Median sternotomy and steel wires for sternal closure are the standard approach for cardiac surgery. An incomplete repair associated with chest wall motion, especially in the presence of predisposing factors, can lead to life-threatening deep sternal wound infection, also known as mediastinitis, in 2-5% of cases. Despite current antibiotic and surgical treatments, mediastinitis is associated with a 10-40% mortality rate and a significant increase in morbidity and hospital stay. High mortality and difficult treatment appear to be due to bacterial biofilm, a self-produced extracellular polymeric product that incorporates host tissue and is responsible for the failure of immune defenses and standard antimicrobial therapies. Nanostructures are an effective strategy to enhance the healing process, as they establish a favorable environment for the neosynthesis of the extracellular matrix, supporting tissue development. Synthetic polymers have been proven to exhibit suitable biodegradable and mechanical properties, and their biofunctionalization to enhance cell attachment and interaction with the extracellular matrix is being widely investigated. The use of antibiotic treatments suspended in poly-D,L-lactide and polyethylene oxide and electrospun into nanofibers, or in sponges, has been shown to inhibit bacterial biofilm production. Additionally, growth factors can be incorporated into 3D bioresorbable scaffolds with the aim of constituting a structural and biological framework to organize and expedite the healing process. Therefore, these combined approaches may change the treatment of mediastinitis in the near future.

Immediate effects of upper limb exercises with and without deep breathing on lung function after cardiac surgery – a randomized crossover trial

BackgroundOpen heart surgery, involving median sternotomy, may cause diminished chest wall motion and restrictive pulmonary function in the early postoperative period. Thoracic and upper extremity range of motion (ROM) exercises are often recommended after surgery but have not been evaluated regarding effect on lung volumes and oxygenation. The objective of this study was to evaluate the immediate effect of upper limb elevations, with or without simultaneous deep breathing, on lung function after cardiac surgery.MethodsIn a randomized 2 × 2 crossover trial, 22 adult patients (> 18 years old) were assessed during one of the first days after surgery in the spring of 2022 at Örebro University Hospital, Sweden. Exercises involving five bilateral upper limb elevations, performed either with simultaneous deep breathing (ROM-DB) or without (ROM), while sitting in an upright position at the edge of the bed, were evaluated. Peripheral oxygen saturation (Rad-5v; Masimo, Irvine, USA) was the primary outcome. Tidal volume and respiratory rate were recorded continuously during the exercises (Spiropalm; Cosmed, Rome, Italy). Heart rate, pain, exertion and dyspnoea were evaluated before and after the exercises.ResultsBoth ROM-DB and ROM momentarily increased peripheral oxygen saturation (+ 1% ± 1, p = 0.004 and + 1% ± 1, p < 0.001, respectively), with no significant differences between these exercises (p = 0.525). ROM-DB significantly increased the VT compared with ROM (798 ± 316 vs. 602 mL ± 176, p = 0.004). However, ROM-DB induced more pronounced pain (p = 0.012), exertion (p = 0.035) and dyspnoea (p = 0.013) than ROM.ConclusionsUpper limb elevations improved oxygenation momentarily, both performed with and without simultaneous deep breathing, with no significant differences between these exercises. The additive deep breathing improved tidal volume compared with upper limb elevations alone, but induced more pain, exertion and dyspnoea during the performance of exercise.Trial registrationClinicalTrials.gov (NCT05278819).

On-board synthetic 4D MRI generation from 4D CBCT for radiotherapy of abdominal tumors: A feasibility study.

Magnetic resonance-guided radiotherapy with an MR-guided LINAC represents potential clinical benefits in abdominal treatments due to the superior soft-tissue contrast compared to kV-based images in conventional treatment units. However, due to the high cost associated with this technology, only a few centers have access to it. As an alternative, synthetic 4D MRI generation based on artificial intelligence methods could be implemented. Nevertheless, appropriate MRI texture generation from CT images might be challenging and prone to hallucinations, compromising motion accuracy. To evaluate the feasibility of on-board synthetic motion-resolved 4D MRI generation from prior 4D MRI, on-board 4D cone beam CT (CBCT) images, motion modeling information, and deep learning models using the digital anthropomorphic phantom XCAT. The synthetic 4D MRI corresponds to phases from on-board 4D CBCT. Each synthetic MRI volume in the 4D MRI was generated by warping a reference 3D MRI (MRIref, end of expiration phase from a prior 4D MRI) with a deformation field map (DFM) determined by (I) the eigenvectors from the principal component analysis (PCA) motion-modeling of the prior 4D MRI, and (II) the corresponding eigenvalues predicted by a convolutional neural network (CNN) model using the on-board 4D CBCT images as input. The CNN was trained with 1000 deformations of one reference CT (CTref, same conditions as MRIref) generated by applying 1000 DFMs computed by randomly sampling the original eigenvalues from the prior 4D MRI PCA model. The evaluation metrics for the CNN model were root-mean-square error (RMSE) and mean absolute error (MAE). Finally, different on-board 4D-MRI generation scenarios were assessed by changing the respiratory period, the amplitude of the diaphragm, and the chest wall motion of the 4D CBCT using normalized root-mean-square error (nRMSE) and structural similarity index measure (SSIM) for image-based evaluation, and volume dice coefficient (VDC), volume percent difference (VPD), and center-of-mass shift (COMS) for contour-based evaluation of liver and target volumes. The RMSE and MAE values of the CNN model reported 0.012±0.001 and 0.010±0.001, respectively for the first eigenvalue predictions. SSIM and nRMSE were 0.96±0.06 and 0.22±0.08, respectively. VDC, VPD, and COMS were 0.92±0.06, 3.08±3.73 %, and 2.3±2.1mm, respectively, for the target volume. The more challenging synthetic 4D-MRI generation scenario was for one 4D-CBCT with increased chest wall motion amplitude, reporting SSIM and nRMSE of 0.82 and 0.51, respectively. On-board synthetic 4D-MRI generation based on predicting actual treatment deformation from on-board 4D-CBCT represents a method that can potentially improve the treatment-setup localization in abdominal radiotherapy treatments with a conventional kV-based LINAC.

Prospective Randomized Trial Comparing 2 Devices for Deep Inspiration Breath Hold Management in Breast Radiation Therapy: Results of the BRAVEHeart Trial

Aims: The BRAVEHeart trial prospectively randomized left-sided breast cancer patients to one of two deep inspiration breath hold (DIBH) biofeedback devices: a novel chest surface tracking system and an abdominal block tracking system. The primary hypothesis was that the accuracy of chest tracking would be higher than that of abdominal tracking as the chest is a more direct surrogate of the breast target.Methods: Left-sided breast cancer patients were treated in DIBH with IMRT delivery. Patients were randomized to either the novel chest surface system or abdominal block system for active management of breath hold with visual feedback. On both trial arms the unallocated system monitored passively.239,296 cine EPID images were analyzed retrospectively to extract the chest wall position. Treatment accuracy was quantified as the deviation of the internal chest wall during treatment relative to the planned position from the digitally reconstructed radiograph. The correlation between motion of the external surrogate and internal chest wall was calculated per breath hold. Ease of use was assessed with questionnaires for both radiation therapists and patients and appointment length recorded.Results: Data from 26 participants were available for analysis. No difference was found in delivered treatment accuracy between arms. Across all patients and fractions, the median correlation between internal chest wall movement and external surrogate was 0.69 for the chest surface and 0.17 for the abdominal block. Patients found it easy to follow visual feedback from both systems. No difference was found in appointment length between arms.Conclusions: No statistical evidence was found for superior treatment accuracy, satisfaction or appointment length for the novel chest surface tracking device compared to the abdominal block system. During DIBH, the median per-breath hold correlation of internal chest wall movement to the motion of the chest surface was higher than the median correlation of the abdominal block to the chest surface.

Evaluation of Chest Wall Motions by Optoelectronic Plethysmography in Scoliosis Patient: A Case Study

Evaluation of Chest Wall Motions by Optoelectronic Plethysmography in Scoliosis Patient: A Case Study

Efficacy of Fixing Chest Tube to Chest Wall from Both Sides versus Single Side Fixation with Silk One Breaded Suture

Efficacy of Fixing Chest Tube to Chest Wall from Both Sides versus Single Side Fixation with Silk One Breaded Suture

Successful resolution of mesenteric tuberculosis and HIV co-infection following 6 months of anti-tuberculosis therapy: a case report

BACKGROUND: Mesenteric tuberculosis (TB), a rare extrapulmonary variant of TB, poses diagnostic and therapeutic challenges in its management. Therefore, discussing a case of mesenteric TB is both intriguing and informative for gaining insights into its clinical presentation and optimal treatment strategies. CASE PRESENTATION: A 50-year-old male presented symptoms of blackish stools three days post-gallstone surgery, accompanied by approximately two months of abdominal discomfort, described as squeezing or stabbing, alleviated temporarily by analgesics, alongside abdominal distension, rigidity, decreased appetite, and afternoon fevers. Physical examination revealed normal vital signs, with pale conjunctiva and asymmetrical chest wall movement, dull percussion, and decreased breath sounds in the lower left hemithorax. Abdominal inspection indicated distension, postsurgical signs, and ascites. Following laboratory investigations, chest and abdominal radiographs, and tissue biopsies, the patient was diagnosed with HIV co-infection along with pulmonary and mesenteric TB. Treatment comprised an intensive phase of four fixed-dose combinations (FDC) of anti-TB drugs, followed by a continuation phase of two FDC tablets, alongside first-line antiretroviral (ARV) therapy and cotrimoxazole prophylaxis. By the sixth month follow-up, clinical improvement was observed, with resolution of symptoms and weight gain to 56 kg. CONCLUSION: This case highlights the effective management of mesenteric TB and HIV co-infection, emphasizing the importance of comprehensive care and collaborative efforts between TB and HIV/AIDS control programs.

Chest Wall Motion Model of Cardiac Activity for Radar-Based Vital-Sign-Detection System.

An increasing number of studies on non-contact vital sign detection using radar are now beginning to turn to data-driven neural network approaches rather than traditional signal-processing methods. However, there are few radar datasets available for deep learning due to the difficulty of acquiring and labeling the data, which require specialized equipment and physician collaboration. This paper presents a new model of heartbeat-induced chest wall motion (CWM) with the goal of generating a large amount of simulation data to support deep learning methods. An in-depth analysis of published CWM data collected by the VICON Infrared (IR) motion capture system and continuous wave (CW) radar system during respiratory hold was used to summarize the motion characteristics of each stage within a cardiac cycle. In combination with the physiological properties of the heartbeat, appropriate mathematical functions were selected to describe these movement properties. The model produced simulation data that closely matched the measured data as evaluated by dynamic time warping (DTW) and the root-mean-squared error (RMSE). By adjusting the model parameters, the heartbeat signals of different individuals were simulated. This will accelerate the application of data-driven deep learning methods in radar-based non-contact vital sign detection research and further advance the field.

Lung Function Evaluated By Structured Light Plethysmography in Children After Lung Surgery: A Preliminary Analysis.

Background: Structured light plethysmography (SLP) is a novel light-based method that captures chest wall movements to evaluate tidal breathing. Methods: Thirty-two children who underwent lung surgery were enrolled. Their clinical history was collected along with spirometry and SLP. Results: Median age of surgery was 9 months (interquartile range 4-30). Most frequent diagnosis was congenital pulmonary airway malformation (14/32), then pulmonary sequestration (9/32), tumor (5/32), and bronchogenic cyst (4/32). The most frequent surgical approach was lobectomy (59%), segmentectomy (38%), and complete resection (3%). More than 80% had surgery when younger than 3 years of age. Eight patients had short-term complications (pleural effusion was the most frequent), while long-term effects were reported in 15 patients (19% recurrent cough, 13% thoracic deformities, 13% airway infections, 9% wheezing, 6% reduced exercise tolerance, and 3% columnar deformities). Spirometry was normal in 9/22 patients. Nine patients had a restrictive pattern, while 4 showed a mild bronco-reactivity. Ten patients did not perform spirometry because of young age. SLP revealed the presence of obstructive pattern in 10% of patients (IE50 > 1.88) and showed a significant difference between the two hemithorax in 29% of patients. Discussion: SLP may be a new method to evaluate lung function, without collaboration and radiation exposure, in children who underwent lung resection, also in preschool age.

Chest wall resections for sulcus superior tumors.

Chemoradiotherapy followed by surgical resection (trimodality therapy) is a guideline recommended treatment for sulcus superior tumors (SST). By definition, SSTs invade the chest wall and therefore require en-bloc chest wall resection with the upper lung lobe or segments. The addition of a chest wall resection, potentially results in higher morbidity and mortality rates when compared to standard anatomical pulmonary resection. This, together with their anatomical location in the thoracic outlet, and varying grades of fibrosis and adhesions resulting from induction chemoradiotherapy in the operation field, make surgery challenging. Depending on the exact location of the tumor and extent to which it invades the surrounding structures, the preferred surgical approach may vary, e.g., anterior, posterolateral, hemi-clamshell, or combined approach; all with their own potential advantages and morbidities. Careful patient selection, adequate staging and discussion in a multidisciplinary tumor board in a center experienced in complex thoracic oncology leads to the best long-term survival outcomes with the least morbidity and mortality. Enhanced recovery guidelines are now available for thoracic surgery, promoting faster recovery and helping to minimize complications and morbidity, including infections and thoracotomy pain. Although minimally invasive surgery can enhance recovery and reduce chest wall morbidity, and is in widespread use in thoracic oncology, its use for SST has been limited. However, this is an evolving area and hybrid surgical approaches (including use of the robot) are being reported. Chest wall reconstruction is rarely necessary, but if so, the prosthetic materials are preferably radiolucent/non-scattering, rigid enough while still being somewhat flexible, and inert, providing structural support, allowing chest wall movement, and closing defects, while inciting a limited inflammatory response. New techniques such as 3D image reconstructions/volume rendering, 3D-printing, and virtual reality modules may help pre-operative planning and informed patient consent.

Assessing the Effect of Chest Orientation on Pulmonary Pressure Under Free Field Shock Waves: A Numerical Analysis

Purpose This study explores how thoracic orientation affects lung pressure and injury outcomes from shock waves, building on earlier research that suggested human posture impacts injury severity. Methods A layered finite element model of the chest was constructed based on the Chinese Visual Human Dataset (CVH), which includes the rib layer and intercostal muscle layer. The dynamic response of the chest under 12 different angles oriented shock waves under incident pressures of 200kPa and 500kPa was calculated. The correspondence between lung pressure at different angles, chest wall motion velocity and lung stress, and differences in pressure/stress of lung tissue behind ribs and intercostal muscle were analyzed. Results The dynamic response of the chest can be roughly divided into four processes. High local intrapulmonary pressure areas were primarily in the anterior lobe margin and lung's central region. A 500kPa incident wave at 0° could cause slight lung injury, whereas at 240°, the pressure was non-harmful. Lung tissue pressure and stress induced by chest wall movement were significantly higher behind the intercostal muscles than behind the ribs, with a difference of about 2-3 times. Conclusions This layered model provides a cost-effective tool for large-scale shock wave impact simulations on the chest. Chest wall movement velocity strongly correlates with lung stress distribution. The significant density and sound velocity differences among ribs, intercostal muscles, and lungs cause an acoustic impedance mismatch, leading to “striped bleeding” marks in post-impact lungs. This research enhances understanding of chest and lung injury mechanisms and informs the development of protective measures.

Long-term outcome after surgical management of symptomatic non-union rib fractures

IntroductionTraumatic chest wall injuries are common however the incidence of non-union rib fractures is unknown. Previous studies have suggested that surgical management of symptomatic non-union rib fractures could be beneficial in selected patients, although many experience persisting pain despite surgery. The aim of this study is to investigate the long-term outcome after surgical management of symptomatic non-union rib fractures. MethodsThis is a cross-sectional study including adults (≥18 years) managed surgically for symptomatic non-union rib fractures with plate fixation during the period 2010–2020 at Sahlgrenska University Hospital. Patients operated for acute chest wall injury or injury due to cardiopulmonary resuscitation were excluded. Patients answered standardized questionnaires concerning remaining symptoms and satisfaction with surgery, quality of life (QoL, EQ-5D-5 L) and disability (Disability Rating Index, DRI). Lung function, movement of chest wall and thoracic spine, and shoulder function (Boström index) were assessed. ResultsSixteen patients, 12 men and four women, with mean age 61.6± 11.1 were included in the study. The mechanism of injury was trauma in 10 patients and cough-induced injuries in five patients. Lung disease was significantly more prevalent in cough-induced injuries compared to traumatic injuries, 5 vs 1 (p = 0.008). The mean follow-up time was 3.5 years. Ninety-four percent were satisfied with the surgery and reported that their symptoms had decreased, although 69 % had remaining symptoms, especially pain, from the chest wall. Quality of Life was decreased with EQ-5D-5 L index 0.819 (0.477–0.976) and EQ-VAS 69 (10–100). Disability Rating Index was 31.5 (1.3–76.7) with problems running, lifting heavy objects, and performing heavy work. Predicted lung function was decreased with Forced Vital Capacity (FVC) 86.2 ± 14.2 %, Forced Expiratory Volume in 1 second (FEV1) 79.1 ± 10.7 % and Peak Expiratory Flow (PEF) 89.7 ± 14.5 %. Patients with cough-induced injuries had full shoulder mobility. ConclusionsChest wall surgery for symptomatic non-union rib fractures results in decreased symptoms and patient satisfaction in most cases despite remaining symptoms, reduced lung function, chest wall movement, and QoL and persistent disability.

A robust treatment planning approach for chest motion in postmastectomy chest wall intensity modulated radiation therapy.

Chest wall postmastectomy radiation therapy (PMRT) should consider the effects of chest wall respiratory motion. The purpose of this study is to evaluate the effectiveness of robustness planning intensity modulated radiation therapy (IMRT) for respiratory movement, considering respiratory motion as a setup error. This study analyzed 20 patients who underwent PMRT (10 left and 10 right chest walls). The following three treatment plans were created for each case and compared. The treatment plans are a planning target volume (PTV) plan (PP) that covers the PTV within the body contour with the prescribed dose, a virtual bolus plan (VP) that sets a virtual bolus in contact with the body surface and prescribing the dose that includes the PTV outside the body contour, and a robust plan (RP) that considers respiratory movement as a setup uncertainty and performs robust optimization. The isocenter was shifted to reproduce the chest wall motion pattern and the doses were recalculated for comparison for each treatment plan. No significant difference was found between the PP and the RP in terms of the tumor dose in the treatment plan. In contrast, VP had 3.5% higher PTV Dmax and 5.5% lower PTV V95% than RP (p<0.001). The RP demonstrated significantly higher lung V20Gy and Dmean by 1.4% and 0.4Gy, respectively, than the PP. The RP showed smaller changes in dose distribution affected by chest wall motion and significantly higher tumor dose coverage than the PP and VP. We revealed that the RP demonstrated comparable tumor doses to the PP in treatment planning and was robust for respiratory motion compared to both the PP and the VP. However, the organ at risk dose in the RP was slightly higher; therefore, its clinical use should be carefully considered.

Novel nomogram for predicting paradoxical chest wall movement in patients with flail segment of traumatic rib fracture: a retrospective cohort study

Flail chest is a severe injury to the chest wall and is related to adverse outcomes. A flail chest is classified as the physiologic, paradoxical motion of a chest wall or flail segment of rib fracture (RFX). We hypothesized that patients with paradoxical chest wall movement would present different clinical features from patients with a flail segment. This retrospective observational study included patients with blunt chest trauma who visited our level 1 trauma center between January 2019 and October 2022 and were diagnosed with one or more flail segments by computed tomography. The primary outcome of our study was a clinically diagnosed visible, paradoxical chest wall motion. We used the least absolute shrinkage and selection operator (LASSO) logistic regression model to minimize overfitting. After a feature selection using the LASSO regression model, we constructed a multivariable logistic regression (MLR) model and nomogram. A total of five risk factors were selected in the LASSO model and applied to the multivariable logistic regression model. Of these, four risk factors were statistically significant: the total number of RFX (adjusted OR [aOR], 1.28; 95% confidence interval [CI], 1.09–1.49; p = 0.002), number of segmental RFX including Grade III fractures (aOR, 1.78; 95% CI, 1.14–2.79; p = 0.012), laterally located primary fracture lines (aOR, 4.00; 95% CI, 1.69–9.43; p = 0.002), and anterior–lateral flail segments (aOR, 4.20; 95% CI, 1.60–10.99; p = 0.004). We constructed a nomogram to predict the personalized probability of the flail motion. A novel nomogram was developed in patients with flail segments of traumatic RFX to predict paradoxical chest wall motion. The number of RFX, Grade III segmental RFX, and the location of the RFX were significant risk factors.

Methods for measuring respiratory rate based on the analysis of chest wall movements

Aim of the review to discuss the respiratory rate (RR) measurement methods that use sensors for analyzing chest wall movements. Strain and movement sensors can be successfully used in real clinical practice, since they can be easily integrated into clothes and garments (electronic textiles) for measuring the respiratory rate in both inpatients and outpatients. Meanwhile, magnetometers, gyroscopes and accelerometers must be located in specific places. One of the main limitations of strain and motion sensors is their sensitivity to patient's breathing-unrelated movements. In order to reduce this limitation, the sensors should most often be placed in the upper part of the chest and integrated into mechanical supports. In addition, it is recommended to use hybrid systems consisting of multiple different sensors. Such systems allow separate analysis of the thoracic and abdominal breathing patterns, providing for wide opportunities to use these sensors for scientific purposes. The use of special polymers and protective materials in a piezoresistive sensors design will allow to overcome their other drawback the possible influence of environmental factors (for example, temperature or humidity). Conclusion. All types of the sensors presented in this review showed generally good quality of respiratory curves at rest during normal breathing. However, in most cases, the bias increased in physical activity. The choice of a certain type of sensor for RR assessment should obviously be based on the specific clinical situation, monitoring duration, monitoring conditions (intensive care unit, inpatient, outpatient department), taking into consideration the advantages and disadvantages.

Alcoholization of intercostal nerves for incident pain due to rib metastases.

Rib metastases may cause incident pain on coughing, deep respiration, or on specific thoracic wall movement. Proper titration of opioid doses relieves the background pain adequately, but does not allow a good pain control for incident pain. A patient with rib metastases presented incident pain due to minimal chest wall movement, limiting breathing. Alcoholization of intercostal nerves at T6,T7, T8, and T9, at level of ribs angle, RESULTS: Intercostal blocks were highly effective in relieving incident pain due to rib metastases. A simple and safe procedure may produce effective analgesia preventing incident pain due to rib metastases. Differently from other sites of bone metastases, ribs are easily localized and the neurolytic block results to be effective and safe.

Assessments of perioperative respiratory pattern with non-contact vital sign monitor in children undergoing minor surgery: a prospective observational study.

Nurses routinely assess respiration of hospitalized children; however, respiratory rate measurements are technically difficult due to rapid and small chest wall movements. The aim of this study is to reveal the respiratory status of small children undergoing minor surgery with load cells placed under the bed legs, and to test the hypothesis that respiratory rate (primary variable) is slower immediately after arrival to the ward and recovers in 2h. Continuous recordings of the load cell signals were performed and stable respiratory waves within the 10 discriminative perioperative timepoints were used for respiratory rate measurements. Apnea frequencies were calculated at pre and postoperative nights and 2h immediately after returning to the ward after surgery. Continuous recordings of the load cell signals were successfully performed in 18 children (13 to 119months). Respiratory waves were appraisable for more than 70% of nighttime period and 40% of immediate postoperative period. There were no statistically significant differences of respiratory rate in any timepoint comparisons (p = 0.448), thereby not supporting the study hypothesis. Respiratory rates changed more than 5 breaths per minute postoperatively in 5 out of 18 children (28%) while doses of fentanyl alone did not explain the changes. Apnea frequencies significantly decreased 2h immediately after returning to the ward and during the operative night compared to the preoperative night. Respiratory signal extracted from load cell sensors under the bed legs successfully revealed various postoperative respiratory pattern change in small children undergoing minor surgery. UMIN (University Hospital Information Network) Clinical Registry: UMIN000045579 ( https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000052039 ).

Breathing Chest Wall Kinematics Assessment through a Single Digital Camera: A Feasibility Study.

The identification of respiratory patterns based on the movement of the chest wall can assist in monitoring an individual's health status, particularly those with neuromuscular disorders, such as hemiplegia and Duchenne muscular dystrophy. Thoraco-abdominal asynchrony (TAA) refers to the lack of coordination between the rib cage and abdominal movements, characterized by a time delay in their expansion. Motion capture systems, like optoelectronic plethysmography (OEP), are commonly employed to assess these asynchronous movements. However, alternative technologies able to capture chest wall movements without physical contact, such as RGB digital cameras and time-of-flight digital cameras, can also be utilized due to their accessibility, affordability, and non-invasive nature. This study explores the possibility of using a single RGB digital camera to record the kinematics of the thoracic and abdominal regions by placing four non-reflective markers on the torso. In order to choose the positions of these markers, we previously investigated the movements of 89 chest wall landmarks using OEP. Laboratory tests and volunteer experiments were conducted to assess the viability of the proposed system in capturing the kinematics of the chest wall and estimating various time-related respiratory parameters (i.e., fR, Ti, Te, and Ttot) as well as TAA indexes. The results demonstrate a high level of agreement between the detected chest wall kinematics and the reference data. Furthermore, the system shows promising potential in estimating time-related respiratory parameters and identifying phase shifts indicative of TAA, thus suggesting its feasibility in detecting abnormal chest wall movements without physical contact with a single RGB camera.

A Real-Time Evaluation Algorithm for Noncontact Heart Rate Variability Monitoring.

Noncontact vital sign monitoring based on radar has attracted great interest in many fields. Heart Rate Variability (HRV), which measures the fluctuation of heartbeat intervals, has been considered as an important indicator for general health evaluation. This paper proposes a new algorithm for HRV monitoring in which frequency-modulated continuous-wave (FMCW) radar is used to separate echo signals from different distances, and the beamforming technique is adopted to improve signal quality. After the phase reflecting the chest wall motion is demodulated, the acceleration is calculated to enhance the heartbeat and suppress the impact of respiration. The time interval of each heartbeat is estimated based on the smoothed acceleration waveform. Finally, a joint optimization algorithm was developed and is used to precisely segment the acceleration signal for analyzing HRV. Experimental results from 10 participants show the potential of the proposed algorithm for obtaining a noncontact HRV estimation with high accuracy. The proposed algorithm can measure the interbeat interval (IBI) with a root mean square error (RMSE) of 14.9 ms and accurately estimate HRV parameters with an RMSE of 3.24 ms for MEAN (the average value of the IBI), 4.91 ms for the standard deviation of normal to normal (SDNN), and 9.10 ms for the root mean square of successive differences (RMSSD). These results demonstrate the effectiveness and feasibility of the proposed method in emotion recognition, sleep monitoring, and heart disease diagnosis.