Medical Devices-Evidence and Research最新文献

Purpose: The change in the amplitude of a peripheral pulse in response to a Valsalva maneuver has diagnostic utility for assessing volume status at the bedside. We have developed a device to automatically quantify the Valsalva pulse response (VPR) to a standardized Valsalva maneuver that the device guides a user to perform. In this study, we sought to determine whether VPR by the device, Indicor, is sensitive enough to detect the acute increase in central pressure and volume load that occurs with a passive leg raise (PLR) in healthy volunteers.

Methods: Healthy volunteers were tested semirecumbently at 45 degrees, then again after being leaned back on a pivoted wedge with legs raised at 45 degrees and torso and head flat, and then again in the semirecumbent position. The device recorded a finger photoplethysmography (PPG) signal during a 10-second expiratory effort of 20 mmHg as guided by the device. VPR was automatically calculated as the ratio of the end-Valsalva pulse amplitude to the baseline pulse amplitude.

Results: In the 30 participants who completed testing, VPR increased from baseline to PLR in every participant, from 0.34 ± 0.13 to 0.60 ± 0.14 (p < 0.0001). Back upright, VPR decreased back to 0.33 ± 0.10 (p < 0.0001 versus PLR; NS versus baseline position).

Conclusion: In this proof-of-concept study of healthy participants, the Indicor device, a noninvasive, convenient device that automatically calculates VPR from a finger photoplethysmography signal during a standardized Valsalva maneuver, was sensitive enough to detect the increase in VPR that occurred with an acute central volume load from a PLR. Future studies should examine whether VPR responds differently to a PLR in heart failure patients with abnormal cardiac performance and/or congestion.

Introduction: The main objective of this study is to evaluate the effectiveness of a newly designed vaginal speculum, the Bouquet Speculum, in-vitro. The setting of this study was at Florida International University and involved four senior students in the Department of Biomedical Engineering.

Methods: A phantom vaginal model was used to test three variables of the Bouquet Speculum (Visibility, Pressure and Gynecologic Tools tests). As this was bench-lab testing with simulated models, no human participants were involved in this study.

Results: The results of this in-vitro study are as follows: The visibility test demonstrated statistically better visualization of the cervix and the cervical os (sampling area for pap tests) with the Bouquet Speculum over the existing 2-bladed speculum at all intrapelvic pressures; The pressure test demonstrated an equal radial distribution of force, without breakage, across the Bouquet Speculum; The gynecologic tools test demonstrated that the Bouquet Speculum is compatible with the existing speculum and standard gynecologic tools in terms of retrieving samples and accessing the cervical os and entire cervix during gynecologic procedures and screening.

Conclusion: The gynecologic screening and procedural value of this innovative change in the design of the vaginal speculum could save hundreds of thousands of lives every year, provide a more comfortable exam for the patient, and result in a more efficient and user-friendly provider experience.

Purpose: This study describes the incremental healthcare costs associated with retreatment among adults undergoing ureteroscopy (URS) or percutaneous nephrolithotomy (PCNL) for upper urinary tract stones (UUTS).

Patients and methods: The IBM^® MarketScan^® Commercial Database was used to identify adults aged 18-64 years with UUTS treated with URS or PCNL between January 2010 and December 2019. Patients had 12 months of continuous insurance coverage before (baseline) and after (follow-up) the first (index) procedure. The primary outcome was total all-cause healthcare costs measured over the 365-day follow-up period, not inclusive of index costs. Generalized linear models were used to estimate the incremental costs associated with retreatment within 90 (early) or 91-365 days post-index (later) relative no retreatment. The models adjusted for demographics, comorbidities, stone(s) location, treatment setting, procedural characteristics (eg, 1-step vs 2-step PCNL) and index year.

Results: Approximately 23% (27,402/119,800) of URS patients were retreated (82% had early retreatments). The adjusted mean total cost was $10,478 (95% CI: $10,281-$10,675) for patients with no retreatment, $25,476 (95% CI: $24,947-$26,004) for early retreatment ($14,998 incremental increase, p<0.01), and $32,868 [95% CI: $31,887-$33,850] for later retreatment ($22,391 incremental increase, p<0.01). Approximately 36% (1957/5516) of PCNL patients were retreated (78% had early retreatments). The adjusted mean total cost was $13,446 (95% CI: $12,659-$14,273) for patients with no retreatment, $37,036 [95% CI: $34,926-$39,145]) for early retreatment ($23,570 incremental increase, p<0.01), and $35,359 (95% CI: $32,234-$38,484) for later retreatment ($21,893 incremental increase, p<0.01).

Conclusion: Retreatment during the first year following URS or PCNL was needed in 23% and 36% of patients, respectively, and was associated with an economic burden of up to $23,500 per patient. The high rate of retreatment and associated costs demonstrate there is an unmet need to improve mid- to long-term results in URS and PCNL.

Introduction: Whilst risk management has become fundamental in the development of medical devices, enforced by regulations and international standards, there is still no comprehensive model that explains how risk management in medical devices' development should be tackled, especially with regard to the type of risks that should be addressed. Risk management in the medical devices' development field is currently focused on technical risks, comprising product, usability, and development process risks, in alignment with standards' requirements and regulations, without giving enough attention to non-technical risks, which include business and project risks. Start-ups within this heavily regulated domain have a key role in the innovation process, yet they suffer a structural lack of tangible, such as financial capacity, and intangible resources such as development, risk management, and regulations' compliance. Nonetheless, they can still optimize their risk identification coverage beyond the enforced requirements to increase their products' chances of success.

Methods: A set of qualitative interviews, serving the adopted grounded theory building research method, with seven start-ups who are involved in the development, commercialization, and quality control of medical devices was accomplished. The purpose was to determine the applied risk management practices and most importantly identify the risk types covered by them. Since every start-up is a project by itself, a sample of project risks, as identified by the project management institute, was utilized to scope the risk coverage and flag missing non-technical risks by the participating start-ups.

Results: Un-identified risk types, lack of involvement of the right teams, and other related loopholes were presented.

Discussion: A list of requirements was developed and sketched in a user-friendly risk management framework, which is believed to be crucial in helping start-ups attain successful, safe, and regulatory compliant medical devices production, is shared in the discussion and proposed framework section of this paper.

Introduction: Simple non-invasive biomarker is urgently needed to detect the largely silent osteopenia in order to prevent osteoporosis-related fracture later in life. The accumulation of advanced glycation end products (AGEs) has been related to reduced bone density and osteoporotic fractures. Whether lens autofluorescence (LAF) based AGEs (LAF-AGEs) measurement could be used to assess the risk of osteopenia is aimed to investigate in this paper.

Methods: Through routine health examination, 368 individuals under the age of 50 were enrolled. A dual-energy X-ray absorptiometry (DXA) device was used to measure bone mineral density (BMD) of the forearm and determine osteopenia. AGE levels were derived with LAF along with the other demographic and laboratory parameters. After deriving the age-adjusted AGE levels (AALs), a linear regression analysis and an ordered logistic regression analysis were applied to examine the associations between osteopenia and LAF-AGEs as well as AALs.

Results: Negative correlations (Pearson r = -0.16, p < 0.001) were found between LAF-AGEs and T-scores. Higher AALs were significantly associated (p = 0.004) with escalated level of osteopenia in the ordered logistic analysis.

Discussion: After reviewing the relevant studies, it is concluded that LAF-AGE is a more stable measure of long-term metabolic dysfunction than circulating AGE. LAF-AGEs are a valid, practical and non-invasive parameter for osteopenia risk evaluation. Further studies with longer follow-up will be helpful to clarify its effectiveness for osteoporosis risk assessment.

Background: Modern surgical staplers should provide precise placement and transection, especially in tight spaces and on thick tissue. Ideally, a stapler would move to accommodate variations in the tissue and anatomy instead of having to move the tissue around to fit the stapler. This study was undertaken to evaluate the performance characteristics of the new Echelon 3000 Stapler (ECH3). Use of the ECH3 was compared to another marketed stapler, including tests for access, seal strength, staple formation in thick tissue, and end effector stability.

Methods: Pelvic anatomy measurements were used to construct a virtual model of a Low Anterior Resection (LAR). Monte Carlo simulations were performed on the staplers to compare the probability of completing a transection with one or two firings. Using water infusion of stapled porcine ileum, pressure at first leak and percentage of leaks at critical pressures were measured. Rate of malformed staples was measured in thick tissue. End effector stability while firing and under moderate pressure were compared between staplers. After use, surgeons were surveyed on the functionality of the device.

Results: ECH3 had a markedly higher probability of completing an LAR transection in one or two firings than the comparator stapler. Median initial leak pressure of stapled ileum was significantly higher, and rate of leaks was lower at 40 and 50 mmHg. ECH3 had fewer malformed staples for both 3.3- and 4.0-mm thick tissue. The end effector exhibited less angular movement during firing, and less deflection under a moderate load. Surgeons agreed the ECH3 provided precise placement and easy one-handed operation.

Conclusion: The Echelon 3000 Stapler demonstrated improved access capability, tighter seals, fewer malformed staples, and greater end effector stability. These advantages were recognized by surgeons who evaluated the use of the device preclinically.

Purpose: To evaluate the rheological properties of the ophthalmic viscoelastic device (OVD) PRO-149, its preclinical safety, and its effectiveness when used during cataract surgery in patients with age-related cataract.

Material and methods: Control (HEC) and test (PRO-149) OVDs were compared through rheological measures, by two preclinical safety studies in rabbits, and under normal-use conditions during cataract removal and lens implantation in a parallel randomized clinical trial.

Results: Rheological properties were determined. Preclinical studies did not find any evidence of safety issues or toxicity. In the clinical trial, 36 subjects were included. After 29 days, there were no statistically significant differences in mean percentage of endothelial cell count change or in the postoperative intraocular pressure between groups. There were no significant differences between OVDs for any safety parameter studied. Finally, PRO-149 showed a statistically significant improvement in surgeon rating for ease of use during extraction (p < 0.05).

Conclusion: PRO-149 is a dispersive OVD. The rabbit models did not find evidence of clinical alterations or toxicity. The results of the clinical study support that the two studied OVDs were clinically similar in terms of safety and effectiveness for cataract surgery.

Trial registration: The trial is registered at Clinical Trials.gov at NCT04702802 (21-01-11).

Introduction: Heart sound signal is an important physiological signal of human body, and the identification and research of heart sound signal is of great significance.

Methods: For abnormal heart sound signal recognition, an abnormal heart sound recognition system, combining hidden semi-Markov models (HSMM) with deep neural networks, is proposed. Firstly, HSMM is used to build a heart sound segmentation model to accurately segment the heart sound signal, and then the segmented heart sound signal is subjected to feature extraction. Finally, the trained deep neural network model is used for recognition.

Results: Compared with other methods, this method has a relatively small amount of input feature data and high accuracy, fast recognition speed.

Discussion: HSMM combined with deep neural network is expected to be deployed on smart mobile devices for telemedicine detection.