Medical Devices-Evidence and Research最新文献

Many developers of medical devices face a new reality with the increasing demand for clinical evidence that is generated by clinical investigations. This affects biotechnology companies, start-ups and academic research centres. The participants' informed consent form (ICF), which includes the participant information sheet (PIS), is among the critical documents that are part of the clinical investigation. While many countries around the world follow the principles of good clinical practice (GCP), there are country-specific variations of the ICF requirements. In addition, many of the country guidelines are focused on medicinal products rather than medical devices. Clinical investigations involving medical devices have their unique challenges and need additional guidance to help developers improve the ICF and PIS content. This review provides information on the latest regulatory recommendations from Europe, USA and Asia regarding the content of the ICF and offers practical advice from professionals experienced in preparing ICFs. It also includes some ethical considerations that must be taken into account.

Purpose: While arterial oxyhemoglobin saturation (SaO₂) decreases during sleep in many patients with sleep apnea and pulmonary diseases, personalized oximeters suitable for multi-night monitoring of SpO₂ are not readily available. The present report describes a custom buccal mucosal intraoral oximeter that might provide the opportunity for such long-term monitoring given its strong accuracy in measuring SpO₂ over a range of clinically relevant hypoxemia.

Patients and methods: The intraoral buccal mucosal oximeter was constructed by encapsulating a reflectance pulse oximeter in an overlay of the maxillary dentition. Accuracy was assessed during non-motion conditions in normal participants (n = 12) made progressively hypoxic by decreasing the partial pressure of end-tidal oxygen (PETO₂). CO-oximeter values of SaO₂ from arterial blood constituted the "gold standard" for comparison with the buccal mucosal oximeter's values. The oximeter's pulse rate and an electrocardiogram (ECG) determined heart rate were also compared.

Results: Analysis of 325 paired SaO₂ values from the CO-oximeter and buccal mucosal oximeter yielded the following: r = 0.95; bias = 0.72; and accuracy root-mean-square (A_RMS) = 2.94%. Results from the pulse rate/ECG analysis were: r = 0.99; bias = 0.30; and A_RMS = 2.08 bpm.

Conclusion: These results reveal robust accuracy of the buccal mucosal oximeter measurement of SaO₂ and pulse rate, as shown by good agreement with a "gold standard" over a wide range of arterial hypoxemia. Such clinically acceptable accuracy indicates that this novel reflectance oximeter may prove useful in management of patients with sleep-induced hypoxemia by allowing for long-term monitoring of SaO₂.

Background: Redo cardiac surgery outcomes, including increased transfusions and risk of reoperation, worsen with post-operative bleeding. This study aimed to directly compare the use of an absorbable polysaccharide powder to no hemostatic agent use during planned non-emergent redo cardiac surgery.

Methods: Fifty-one participants in two cohorts underwent planned non-emergent redo cardiac surgery. The retrospective cohort (n = 26) was chosen from redo cardiac surgeries completed between 2019 and 2020, while the prospective cohort (n = 25) included sequential redo cardiac surgeries with the use of an absorbable polysaccharide powder. Patient operative characteristics, along with first 24-hour transfusion use (packed red blood cells (pRBC), fresh frozen plasma (FFP) and platelets (Plts), chest tube outputs (CTO) at 12, 24 and 48 hours, and reoperation rates were compared.

Results: There was a higher non-statistical average of intraoperative pRBC and FFP rates in the retrospective cohort, compared to cases where absorbable polysaccharide powder was used (2 ± 2.9 vs 1.1 ± 1.4 units pRBC, p = 0.414; and 1.4 ± 1.8 vs 0.6 ± 1 units FFP, p = 0.070) while there were statistical differences in Plts use in the retrospective cohort compared to when absorbable polysaccharide powder was used (1 ± 1.3 vs 0.4 ± 0.7 units plts, p = 0.028). Statistically significant lower amounts of CTO in the first 12 hours and the 12-24-hour intervals were found when absorbable polysaccharide powder was used (817 ± 520 vs 558 ± 352 milliliters, p = 0.028; and 1144 ± 704 vs 830 ± 474 milliliters, p = 0.044, respectively). There were three reoperations in the retrospective cohort due to suspected bleeding, compared to no reoperations in the absorbable polysaccharide powder cohort.

Conclusion: This study highlights fewer transfusions, lower CTO, and decreased need for reoperation when using absorbable polysaccharide powder in redo cardiac surgeries. Further randomized trials are needed to more accurately define benefits of absorbable polysaccharide powder in redo cardiac surgeries. Word count: 302.

Importance: Safety issues leading to patient harm and significant costs have been identified in several post-market medical devices. Recently, powerful learning effects (LE) have been documented in numerous medical devices. Correctly attributing safety signals to learning or device effects allows for appropriate corrective actions and recommendations to improve patient safety.

Objective: To develop and assess the statistical performance of an analytic framework to detect the presence of LE and quantify the learning curve (LC).

Design and setting: We generated synthetic datasets based on observed clinical distributions and complex feature correlations among patients hospitalized at US Department of Veterans Affairs facilities. Each dataset represents a hypothetical early experience in the use of high-risk medical devices, with a device of interest and a reference device. The study blinded the analysis team to the data-generation process.

Methods: We developed predictive models using generalized additive models and estimated LC parameters using the Levenberg-Marqualdt algorithm. We evaluated the performance using sensitivity, specificity, and likelihood ratio (LR) in detecting the presence of LE and, if present, the goodness-of-fit of the estimated LC based on the root-mean squared error.

Results: Among the 2483 simulated datasets, the median (IQR) number of cases was 218,000 (116,000-353,000). LE were detected in 2065 of the 2291 datasets for which learning was specified (sensitivity: 90%; specificity: 88%; LR: 7). We adequately estimated the LC in 1632 (81%) of the 2013 datasets in which LE was detected and estimated LC.

Discussion: This study demonstrated the framework to be robust in disentangling LE from device safety signals and in estimating LC.

Conclusion: In medical device safety evaluation, the operator-learning effects associated with the safety of medical devices can be effectively modeled and characterized. This study warrants subsequent framework validation by using real-world clinical datasets.

Background: Human papillomavirus (HPV) is a leading cause of cervical cancer worldwide, with HPV type 16 accounting for roughly half of cases. Although polymerase chain reaction (PCR) is considered the gold standard for HPV detection, its reliance on gel electrophoresis can be costly and require specialized facilities.

Objective: We developed a diagnostic approach integrating PCR with a lateral flow assay to detect HPV type 16 using gold nanoparticles as visible labels.

Methods: Primers targeting the L1 gene of HPV 16 were labeled with 6FAM (forward) and biotin (reverse). Amplified products were applied to lateral flow strips preloaded with streptavidin-gold nanoparticle conjugates. Visible red bands on the test and control lines indicated successful detection.

Results: The optimized assay produced a clear band at ~333 bp by gel electrophoresis and yielded distinct red lines on the lateral flow strip for positive samples. Compared to electrophoresis, this format has a faster turnaround and can reduce costs by eliminating bulky equipment.

Conclusion: This simplified and cost-effective method provides a user-friendly alternative to traditional electrophoresis, making it suitable for resource-limited settings. Further large-scale clinical validation is warranted, including cost analyses and multiplexing for additional genotypes.

Through the ages, the methods of wound dressing have been changing to obtain the best therapeutic effect. The driving force of the process is the development of knowledge and tools. One of the state-of-the-art methods is negative pressure wound therapy. The article presents the results of experimental studies on wound models made in ballistic gel casts and dressed with a vacuum dressing.

Methods: The experiments were performed on samples made of ballistic gel. In the casts, holes were cut out to simulate a wound. Wounds were closed with a dressing connected to a pump, creating a negative pressure. Every model was photographed in two perpendicular sections before and after applying the negative pressure. The changes in shape and size were compared. The numerical model of the wound was also created to confirm experimental observation.

Results: A comparison of wound geometry before and after applying negative pressure reveals a reduction in size in every case. The volume of the wound was reduced by 40%, while its surface area decreased by 27%. This reduction effect was independent of wound size. Furthermore, numerical computations indicate that veins terminating in wounds also reduce in size, with their shape becoming flattened.

Conclusion: The results of experiments and numerical analyses reveal that vacuum dressing can effectively reduce the surface area of the wound by shrinking it and decreasing blood vessel outlets, positively influencing the bleeding reduction. An additional effect is compressive stress in the circumferential direction of the wound, which prevents further development of the wound.

Purpose: The existing 2-bladed vaginal speculum has limitations and barriers to gynecologic diagnosis and treatment. This study aimed to evaluate three of these limitations (visualization of the cervix, ease of use, and relative comfort) using a newly designed vaginal speculum that was hypothesized to overcome these limitations.

Methods: This pilot prospective observational clinical study was conducted at five hospitals in Karachi, Pakistan. Six clinicians were surveyed using two questions on the visibility of the cervix and ease of use of the new vaginal speculum. A total of 100 patients were surveyed to determine the relative comfort of the new speculum.

Results: Clinicians rated the visualization of the cervix as "better" in 66% of women (p=0.0007). The newly designed vaginal speculum was reported by clinicians as "easier" to use in 57% of patients (p=0.0808). The survey results indicated that 53% of participants felt less discomfort with the new speculum (p=0.2743). There was a strong statistical correlation between clinician visualization of the cervix and ease of use (+0.8234, p < 0.0001), visualization and comfort (+0.8978, p < 0.0001), and ease of use and comfort (+0.9101, p < 0.0001).

Conclusion: This new vaginal speculum demonstrated improved cervical visualization and ease of use in a cohort of 100 Pakistani women. In addition, participants in this study reported less discomfort with the new speculum. There is a potential benefit for all gynecologic screening and treatment with this new vaginal speculum design, especially in resource-constrained countries and in certain disadvantaged populations. The newly designed speculum has been field-tested in multiple countries over the last 5 years. Further clinical studies with larger cohorts are warranted.

Objective: To assess the utility of digital biomarkers derived from a head-mounted wearable physiological vibration acceleration (phybrata) sensor to quantify age-related balance impairments, sensory reweighting, and fall risks in older populations.

Methods: Data were collected and analyzed from 516 participants aged 77.7 ± 8.0 yrs (min 51 yrs, max 98 yrs, 334 females, 182 males) in 4 residential senior living communities. Participants first completed a questionnaire that included their fall history in the past 6 months. A 2-minute standing balance test was then carried out for each participant using the phybrata sensor (1 minute with eyes open, followed by 1 minute with eyes closed). Four balance performance biomarkers were derived from the phybrata time series data: eyes open (Eo) and eyes closed (Ec) phybrata powers, average phybrata power (Eo+Ec)/2, and Ec/Eo phybrata power ratio. Sensory reweighting biomarkers were derived from phybrata acceleration spectral density (ASD) distributions. Results are compared for participants with no reported fall history (NF) and those reporting one or more falls (FR) in the previous 6 months.

Results: All four phybrata balance performance biomarkers show significantly higher values for FR participants vs NF participants. As a fall risk biomarker, Ec phybrata power was found to have the strongest statistical correlation with the reported retrospective incidence of falls within the previous 6 months. The Ec phybrata biomarker also showed the strongest statistical difference between F and M participants. Phybrata sensory reweighting biomarkers quantify age-related impairments and sensory reweighting across sensory inputs (visual, vestibular, proprioceptive), central nervous system (CNS) processing, and neuromotor control (vestibulocollic reflex), revealing progressive reductions in visual and vestibular balance regulation and vestibulocollic head stabilization that are offset by an increasing reliance on proprioceptive balance control.

Conclusion: Phybrata digital biomarkers enable rapid objective assessment of progressive age-related balance impairments, sensory reweighting, and fall risks in older populations.

Purpose: Measuring maximal airway pressure is an essential part of the assessment of respiratory functions. Portable handheld devices have made clinical measurements more available, but reliable and user-friendly devices for non-clinical use remain rare. This study sought to determine the validity and short-term repeatability of measurements of dynamic maximal inspiratory pressure (dMIP) and dynamic maximal expiratory pressure (dMEP) by using a novel self-administered respiratory health meter (WellO2-RHM) in asymptomatic young adults.

Patients and methods: dMIP and dMEP were measured with WellO2-RHM in asymptomatic adult volunteers (n=26, 15 male and 11 female, age 26-41 years). These values were compared with quasi-static maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) obtained from the same volunteers using another respiratory manometer (MicroRPM). The measurements of dMIP and dMEP with WellO2-RHM were repeated in the same individuals at an interval of one week for assessment of their short-term repeatability.

Results: The Pearson correlation coefficients of dMIP and dMEP values with MIP and MEP values were high (r=0.840, p<0.001; r=0.849, p<0.001, respectively). The dMIP and dMEP values were consistently lower than the quasi-static MIP and MEP values in the same individuals. The short-term repeatability of the dMIP and dMEP in one week interval proved to be moderately good in terms of the coefficient of variation (CV), the intraclass correlation coefficient (ICC), the standard error of measurement (SEm) and minimal detectable change (MDC) (10.0%, 0.825, p<0.001, 7 cmH2O and 20 cmH2O and 9.1%, 0.895, p<0.001, 12 cmH2O and 34 cmH2O, respectively).

Conclusion: The results indicate that the WellO2-RHM is a valid and repeatable method for the assessment of dMIP and dMEP in asymptomatic young adults, but the absolute values are lower than those obtained with devices measuring quasi-static MIP and MEP. The findings suggest that WellO2-RHM can be used for self-monitoring of the effects of respiratory muscle training in healthy young adults.

Introduction: A novel Neuro-Bio-Electric-Stimulation device (Neubie, Neufit, Austin, Texas, USA) using Direct Current (DC) has been used to treat various neurological conditions (ALS, MS, peripheral neuropathy, chronic pain) and functional limitations such as limited range of motion. One method, called the Master Reset Protocol, is thought to stimulate the vagus nerve system, impacting heart rate, digestion and other vital systems.

Purpose: We used the Master Reset Protocol on a subject experiencing paroxysmal Atrial Fibrillation (AFib) to assess whether this treatment might be effective in reversing a cardiac arrhythmia.

Subject and methods: A single subject is reported in this Case Report. The subject is a 62-year-old healthy, athletic male, 6'2″ tall, 165 lbs. with a good diet and is not obese nor has other exacerbating underlying conditions related to heart disease. The subject experiences arrhythmia approximately 1-2 times per month lasting generally 3 or more days per the subject. The Master Reset Method was initiated within 12 hours of arrhythmia onset, and arrhythmia before and after treatment was confirmed through subject observation and confirmed with pulse readings. A total of ten treatments were conducted over 7 months.

Results: Reversal of arrhythmia was confirmed during or within 24 hours of treatment with DC application for all 10 treatments (100%). Two of the more severe cases of AFib required two treatments on the same day with confirmed reversal of AFib.

Conclusion: Treatment with Direct Current suggests a good correlation with reversal of arrhythmia. Further studies are planned to determine if similar, regular, treatments can be effective in preventing arrhythmia.