Size Of Implants Research Articles

The Impact of Disc Height on Outcomes Following Cervical Disc Replacement: A Systematic Review.

Systematic review. Describe the impact of disc height on outcomes following cervical disc replacement (CDR). Implant sizing and positioning may impact outcomes following CDR. A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using the EMBASE and PubMed databases. The goal of this review was to assess the impact of postoperative "disc height" on clinical and radiologic outcomes following CDR. A total of 12 studies were included in the systematic review. In the literature. "disc height" was assessed using multiple different measures: postoperative disc height (DH; n=4), disc height change (DHC; n=4), degree of disc distraction (DDD; n=2), prosthesis height (PH; n=2), functional spinal unit height (FSUH; n=2), and facet distraction (FD; n=1). DH and DHC were the most common measures studied. DHC was associated with statistically and clinically significant differences in several patient-reported outcomes measures (PROMs). However, DH was not associated with any statistically or clinically significant differences in PROMs. With respect to cervical range of motion (ROM), DHC appeared to demonstrate statistically and clinically relevant differences in some of the studies included in this review, while DH was associated with statistically, but not clinically, significant differences. The majority of studies identified DHC <2mm as an important cutoff to optimize outcomes. "Disc height," especially as measured by DHC, may be an important intraoperative consideration when selecting implant size during CDR. Maintaining DHC <2mm may optimize PROMs and ROM. Improving technique and implant sizing may aid in translating ex vivo advantages in implant mobility to in vivo improvements in ROM and PROMs.

Assessing proximal humerus cortical bone thickness for total shoulder arthroplasty: A cadaveric study

BackgroundIn reverse total shoulder arthroplasty, a humeral osteotomy is typically performed at the anatomic neck. The quality and quantity of cancellous and cortical bone impacts sizing of implants. Little-to-no information exists characterizing the transition of this bone quality at this location. This cadaveric study focused on measuring and analyzing the transition zone of the proximal humerus bone quality to better understand the implications of utilizing different implant sizes during reverse total shoulder arthroplasty. This assessment was conducted through the usage of a newly designed indentation depth probe. MethodsAn Exactech, Inc. designed indentation depth probe was used to assess the transition from cancellous to cortical bone in 45 cadavers after a humeral osteotomy was performed. The thickness of the cortical rim was measured in regard to superior, inferior, anterior, and posterior quadrants. Linear regressions were utilized to evaluate the relationship between anatomic location in regard to cortical bone thickness. Independent sample two-tailed t-tests were also conducted to examine the relationship between spring force and bone thickness. Finally, independent sample two-tailed t-tests or Mann-Whitney U tests were utilized to examine the relationship between cortical thickness and variables including sex, age, osteoporosis, and a diagnosis of cancer. ResultsAll linear regressions were found to be insignificant excluding the relationships between inferior to anterior (p=0.003) and inferior to posterior (p=0.001). All t-tests and Mann-Whitney U tests were found to be insignificant, except for the relationship between age and the posterior aspect (p=0.04). ConclusionsIn our cohort, cortical bone thickness was not impacted by sex, diagnosis of osteoporosis, or diagnosis of cancer. Interestingly, age was found to only have an impact on the posterior aspect of the cortical bone rim. Differences in cortical bone thickness were also found in regard to both the inferior to anterior and inferior to posterior comparisons. Clinical RelevanceThis suggests that differences in cortical bone thickness can occur, and that one point of assessment might not be sufficient.

Generation of a virtual cohort of TAVI patients for in silico trials: a statistical shape and machine learning analysis.

In silico trials using computational modeling and simulations can complement clinical trials to improve the time-to-market of complex cardiovascular devices in humans. This study aims to investigate the significance of synthetic data in developing in silico trials for assessing the safety and efficacy of cardiovascular devices, focusing on bioprostheses designed for transcatheter aortic valve implantation (TAVI). A statistical shape model (SSM) was employed to extract uncorrelated shape features from TAVI patients, enabling the augmentation of the original patient population into a clinically validated synthetic cohort. Machine learning techniques were utilized not only for risk stratification and classification but also for predicting the physiological variability within the original patient population. By randomly varying the statistical shape modes within a range of ± 2σ, a hundred virtual patients were generated, forming the synthetic cohort. Validation against the original patient population was conducted using morphological measurements. Support vector machine regression, based on selected shape modes (principal component scores), effectively predicted the peak pressure gradient across the stenosis (R-squared of 0.551 and RMSE of 11.67mmHg). Multilayer perceptron neural network accurately predicted the optimal device size for implantation with high sensitivity and specificity (AUC = 0.98). The study highlights the potential of integrating computational predictions, advanced machine learning techniques, and synthetic data generation to improve predictive accuracy and assess TAVI-related outcomes through in silico trials.

The Accuracy of CT-Based Three-Dimensional Templating in Predicting Implant Sizes in Patients Undergoing Robot-Assisted Total Knee Arthroplasty.

Computed tomography (CT) based three-dimensional templating is increasingly being used to predict implant sizes in total knee arthroplasty (TKA). However, the existing data is heterogeneous, and the majority of studies lack adequate statistical power. This study investigated whether preoperative CT-based planning in robot-assisted TKA (RA-TKA) helps in predicting the accurate size of implant used. This is a single-center retrospective study of 632 consecutive RA-TKA surgeries. All surgeries were performed using a fully automatic Cuvis RA-TKA system. Cohen's Kappa (κ) coefficient was used to measure the level of agreement between the predicted and the final implant sizes. A total of 632 knees were operated on 384 patients. A total of 136 unilateral cases whereas 248 patients had both knees operated on. For the tibial component, in 21.7% cases a bigger implant size was used while in 11.8% cases a smaller size was used. For the femoral component, in 5.1% cases a bigger implant size was used while in 4.9% cases a smaller size was used. The agreement between the predicted and actual implant sizes was moderate for the tibial component [κ = 0.56 (95% CI: 0.51 to 0.61); p < 0.001] and almost perfect for the femoral component [κ = 0.87 (95% CI: 0.84 to 0.90); p < 0.001]. This study suggests that planning of RA-TKA using a CT-based model can be valuable to surgeons in accurately predicting the component size for femur and to a lesser degree for tibia. Future studies should investigate the potential predictors of discordance between the predicted and actual tibial implant sizes.

A forecasting model for suitable dental implantation in canine mandibular premolar region based on finite element analysis

In recent years, dental implants have become a trend in the treatment of human patients with missing teeth, which may also be an acceptable method for companion animal dentistry. However, there is a gap challenge in determining appropriate implant sizes for different dog breeds and human. In this study, we utilized skull computed tomography data to create three-dimensional models of the mandibles of dogs in different sizes. Subsequently, implants of various sizes were designed and subjected to biomechanical finite element analysis to determine the optimal implant size. Regression models were developed, exploring the relationship between the average weight of dogs and the size of premolar implants. Our results illustrated that the regression equations for mean body weight (x, kg) and second premolar (PM2), third premolar (PM3), and fourth premolar (PM4) implant length (y, mm) in dogs were: y = 0.2785x + 7.8209, y = 0.2544x + 8.9285, and y = 0.2668x + 10.652, respectively; the premolar implant diameter (mm) y = 0.0454x + 3.3506, which may provide a reference for determine suitable clinical implant sizes for dogs.

Artificial Intelligence Machine Learning Algorithms Versus Standard Linear Demographic Analysis in Predicting Implant Size of Anatomic and Reverse Total Shoulder Arthroplasty.

Accurate and precise templating is paramount for anatomic total shoulder arthroplasty (TSA) and reverse total shoulder arthroplasty (RSA) to enhance preoperative planning, streamline surgery, and improve implant positioning. We aimed to evaluate the predictive potential of readily available patient demographic data in TSA and RSA implant sizing, independent of implant design. A total of 578 consecutive, primary, noncemented shoulder arthroplasty cases were retrospectively reviewed. Demographic variables and implant characteristics were recorded. Multivariate linear regressions were conducted to predict implant sizes using patient demographic variables. Linear models accurately predict TSA implant sizes within 2 millimeters of humerus stem sizes 75.3% of the time, head diameter 82.1%, head height 82.1%, and RSA glenosphere diameter 77.6% of the time. Linear models predict glenoid implant sizes accurately 68.2% and polyethylene thickness 76.6% of the time and within one size 100% and 95.7% of the time, respectively. Linear models accurately predict shoulder arthroplasty implant sizes from demographic data. No significant statistical differences were observed between linear models and machine learning algorithms, although the analysis was underpowered. Future sufficiently powered studies are required for more robust assessment of machine learning models in predicting primary shoulder arthroplasty implant sizes based on patient demographics.

Surgical Bone Implantation Technique for Rat Tibia Models of Diabetes and Osteoporosis.

The rat has long served as a valuable animal model in implant dentistry and orthopedics, particularly in studying the interactions between biomaterials and bone tissue. The rat's tibia is frequently chosen due to its easy surgical access through thin tissue layers (skin and muscle) and the flattened shape of its medial face, facilitating the surgical insertion of intraosseous devices. Additionally, this model enables the induction of specific diseases, mimicking various clinical conditions to assess biological responses to different implant conditions like geometry, surface texture, or biological cues. However, despite its robust cortical structure, certain intraosseous devices may require adaptations in design and size for successful implantation. Therefore, establishing standardized surgical methods for manipulating both soft and hard tissues in the implantation region is essential for ensuring proper implant or screw device placement, particularly in fields like implant dentistry and orthopedics. This study included eighty Sprague Dawley rats divided into two groups based on their respective diseases: Group 1 with osteoporosis and Group 2 with Type 2 Diabetes. Implantations were performed at 4 weeks and 12 weeks, with the same surgeon following a consistent surgical technique. A positive biological response was observed, indicating complete osseointegration of all implants placed. These results validate the success of the surgical protocol, which can be replicated for other studies and serve as a benchmark for the biomaterials community. Notably, osseointegration values remained stable at both 4 weeks and 12 weeks for both disease models, demonstrating a durable integration of the implant over time and emphasizing the establishment of an intimate bone connection as early as 4 weeks.

Comparison of range of motion between 2-year clinical outcomes and predictions of a static scapula preoperative planning software for reverse shoulder arthroplasty

BackgroundPreoperative planning has gained popularity in the management of reverse shoulder arthroplasty (RSA). Commercially available software provides 3-dimensional segmentation of scapula and humerus, as well as providing arc of motion for the implanted articulation and identifying potential areas of bony impingement. However, these software algorithms use a fixed scapula model, disregarding the preoperative clinical range of motion (C-ROM) of the patient, be it glenohumeral or scapulothoracic, as well as any soft tissue parameters. This study aims to compare the ROM based on preoperative planning software by using the implant position from postoperative computed tomography (CT) images (predicted ROM using preoperative planning software [P-ROM]), with the C-ROM assessed at minimum of 2 years of follow-up. MethodsPreoperative and postoperative CT scans of 46 patients who underwent primary RSA between 2017 and 2021 were analyzed. At the postoperative 2-year review, each patient was assessed for active ROM. Implant size and position based on operative notes and postoperative CT scans were used to replicate the performed surgery in the planning software. Abduction, flexion, and external rotation motion were simulated and recorded. The relationship between C-ROM and P-ROM was investigated using linear regression analysis, Pearson correlation coefficient, and paired t-test. ResultsP-ROM was significantly lower than C-ROM at 2 years postoperatively (P < .001), with an average discrepancy of 78° in abduction, 47° in flexion, and 37° in external rotation (C-ROM: abduction 155° ± 21° [80°-180°]; flexion 160° ± 17° [90°-180°]; external rotation 52° ± 14° [10°-80°] vs. P-ROM: abduction 77° ± 13° [53°-107°]; flexion 112° ± 25° [67°-180°]; external rotation 15° ± 21° [0°-79°]). The linear regression analysis indicated weak agreement between C-ROM and P-ROM (abduction R2 = 0.03; flexion R2 = 0.01; external rotation R2 = 0.04). Pearson’s correlation coefficients revealed weak correlations of −0.18, 0.03, and 0.21 for abduction, flexion, and external rotation, respectively. ConclusionP-ROM based on preoperative software in its current form does not allow the prediction of the C-ROM at 2 years of follow-up for patients undergoing RSA.

Outcomes of primary total hip arthroplasty in patients with Ehlers Danlos Syndromes.

The Ehlers Danlos Syndromes (EDS) are inherited in an autosomal dominant pattern and patients classically present with hypermobility, skin hyper-elasticity, blood vessel fragility and atrophic scarring. Due to hypermobility, disorders such as joint pain and early arthritis are common. The aim of this study was to assess clinical and radiological outcomes of total hip arthroplasty (THA) in patients with EDS treated in a high volume orthopaedic centre. A search was performed of the electronic patient record system at our institution from 1998 - 2019 using the search terms 'EDS' or 'Danlos' and 'arthroplasty'. Over the 22-year study period, there were approximately 32,000 primary THAs performed at our institution. We collated demographic information including age, gender, BMI, smoking history and medical comorbidities. Implant type, bearing surfaces and size was also documented, with clinical and radiological assessment at last known follow up. A total of n=5 primary THAs were identified in n=4 patients at a median follow-up of 3 years. All patients were female with a median age of 68 (SD 18.9) years and a median BMI of 30.7 (SD 4.5). The majority of patients were smokers, and had a chronic history of low back pain (n=3, 75%). Uncemented implants were used on n=3 occasions with the remainder being hybrid (n=2). Femoral head size ranged from 28mm to 44mm. One patient had a post-operative surgical wound erythema that resolved within 48 hours of onset, otherwise there were no significant wound complications. To date, there have been no documented dislocations, with all patients having satisfactory clinical and radiological outcome at last known follow up. This study demonstrates that total hip arthroplasty can be safely performed in patients with a diagnosis of EDS, with no significant complications in the intermediate term.

Interscapular Pain after Anterior Cervical Discectomy and Fusion: Does Zygapophyseal Joints over Distraction Play a Role?

Introduction: Anterior cervical discectomy and fusion (ACDF) for cervical disc herniation (CDH) is commonly performed. Specific post-operative complications include dysphagia, dysphonia, cervicalgia, adjacent segment disorder, cage subsidence, and infections. However, interscapular pain is commonly reported by these patients after surgery, although its mechanisms have not been clarified yet. Methods: This retrospective series of 31 patients undergoing ACDF for CDH at a single Academic Hospital. Baseline and post-operative clinical, radiological, and surgical data were analyzed. The linear regression analysis was conducted to identify any factor independently influencing the incidence rate of post-operative interscapular pain. Results: The mean age was 57.6 ± 10.8 years, and the M:F ratio was 2.1. Pre-operative mean VAS-arm was 7.15 ± 0.81 among the 20 patients reporting brachialgia, and mean VAS-neck was 4.36 ± 1.43 among those 9 patients reporting cervicalgia. At 1 month, interscapular pain was still reported by 8 out of the 17 patients who experienced it post-operatively, and it was recovered in all patients after 2 months. The regression analysis showed that interscapular pain was not directly associated with age (p = 0.74), gender (p = 0.46), smoking status (p = 0.44), diabetes (0.42), pre-operative brachialgia (p = 0.21) or cervicalgia (p = 0.48), symptoms duration (p = 0.13), baseline VAS-arm (p = 0.11), VAS-neck (p = 0.93), or mJOA (p = 0.63) scores, or disc height modification (p = 0.90). However, the post-operative increase in the mean zygapophyseal joint rim distance was identified as an independent factor in determining interscapular pain (p = 0.02). Conclusions: Our study revealed that the onset of interscapular pain following ACDF may be determined by over distraction of the zygapophyseal joint rim. Then, proper sizing of prosthetic implants could reduce this painful complication.

Optimal Implant Sizing Using Machine Learning Is Associated With Increased Range of Motion After Cervical Disk Arthroplasty.

Cervical disk arthroplasty (CDA) offers the advantage of motion preservation in the treatment of focal cervical pathology. At present, implant sizing is performed using subjective tactile feedback and imaging of trial cages. This study aims to construct interpretable machine learning (IML) models to accurately predict postoperative range of motion (ROM) and identify the optimal implant sizes that maximize ROM in patients undergoing CDA. Adult patients who underwent CDA for single-level disease from 2012 to 2020 were identified. Patient demographics, comorbidities, and outcomes were collected, including symptoms, examination findings, subsidence, and reoperation. Affected disk height, healthy rostral disk height, and implant height were collected at sequential time points. Linear regression and IML models, including bagged regression tree, bagged multivariate adaptive regression spline, and k-nearest neighbors, were used to predict ROM change. Model performance was assessed by calculating the root mean square error (RMSE) between predicted and actual changes in ROM in the validation cohort. Variable importance was assessed using RMSE loss. Area under the curve analyses were performed to identify the ideal implant size cutoffs in predicting improved ROM. Forty-seven patients were included. The average RMSE between predicted and actual ROM was 7.6° (range: 5.8-10.1) in the k-nearest neighbors model, 7.8° (range: 6.5-10.0) in the bagged regression tree model, 7.8° (range: 6.2-10.0) in the bagged multivariate adaptive regression spline model, and 15.8° (range: 14.3-17.5°) in a linear regression model. In the highest-performing IML model, graft size was the most important predictor with RMSE loss of 6.2, followed by age (RMSE loss = 5.9) and preoperative caudal disk height (RMSE loss = 5.8). Implant size at 110% of the normal adjacent disk height was the optimal cutoff associated with improved ROM. IML models can reliably predict change in ROM after CDA within an average of 7.6 degrees of error. Implants sized comparably with the healthy adjacent disk may maximize ROM.

Effects of Home Cage Tunnels on Within-cage Behaviors of Mice with Cranial Implants.

Keeping tunnels in the home cages of mice used in research appears to both reduce handling-related stress and provide environmental enrichment. However, for mice that have surgical implants that extend beyond their body, having tunnels in the home cages could engender concerns for their welfare, including the possibility of them becoming stuck in the tunnel. The goal of this study was to determine how mice with different sizes of cranial implants interacted with a tunnel in their home cage. We used male and female mice with a C57BL/6J background in this study. The mice underwent a either a craniotomy in which they received either no implant (sham), an indwelling cannula used for drug delivery, or a ferrule-type implant. The number of mouse interactions with tunnels was recorded over a 30-min period while the mouse was in its home cage with its tunnel. We found that sham mice interacted significantly more with the tunnels than did mice with either cannulae or ferrule implants. On average sham mice interacted more with the tunnel by walking through or over it whereas mice with either type of implant rarely even touched the tunnel with their heads. Our results indicate that mice with implants do not enter in the tunnels, and thus the tunnel reduces accessible cage-space rather than providing enrichment benefits. These results raise the question of whether tunnels should be routinely available for mice with cranial implants.

Three-Dimensional Printing Methods for Bioceramic-Based Scaffold Fabrication for Craniomaxillofacial Bone Tissue Engineering.

Three-dimensional printing (3DP) technology has revolutionized the field of the use of bioceramics for maxillofacial and periodontal applications, offering unprecedented control over the shape, size, and structure of bioceramic implants. In addition, bioceramics have become attractive materials for these applications due to their biocompatibility, biostability, and favorable mechanical properties. However, despite their advantages, bioceramic implants are still associated with inferior biological performance issues after implantation, such as slow osseointegration, inadequate tissue response, and an increased risk of implant failure. To address these challenges, researchers have been developing strategies to improve the biological performance of 3D-printed bioceramic implants. The purpose of this review is to provide an overview of 3DP techniques and strategies for bioceramic materials designed for bone regeneration. The review also addresses the use and incorporation of active biomolecules in 3D-printed bioceramic constructs to stimulate bone regeneration. By controlling the surface roughness and chemical composition of the implant, the construct can be tailored to promote osseointegration and reduce the risk of adverse tissue reactions. Additionally, growth factors, such as bone morphogenic proteins (rhBMP-2) and pharmacologic agent (dipyridamole), can be incorporated to promote the growth of new bone tissue. Incorporating porosity into bioceramic constructs can improve bone tissue formation and the overall biological response of the implant. As such, employing surface modification, combining with other materials, and incorporating the 3DP workflow can lead to better patient healing outcomes.

Outcomes of treatment with short dental implants compared with standard-length implants: a retrospective clinical study

BackgroundThe size of dental implants is a key success factor for appropriate osseointegration. Using shorter implants allows the possibility of avoiding complex surgical procedures and reduces the morbidity of treatment. Shorter implants also enable implant-prosthetic rehabilitation after maxillofacial reconstructions where only limited bone is available. In this study, the success rates of short implants were examined and compared to those of standard-sized implants.MethodsPatients who received dental implants between 2007 and 2016 at the Department of Oro-Maxillofacial Surgery and Stomatology Semmelweis University were enrolled in the study. Several clinical parameters were recorded and supplemented with radiological examinations. The data were statistically analysed.ResultsThirty-four patients with a total of 60 implants were included. The average time after prosthetic loading was 39.33 ± 21.96 months in the group with 8-mm implants and 41.6 ± 27.5 months in the group with > 8-mm implants. No significant differences were observed between the two groups in terms of probing depth (short implants, 2.84 ± 0.09 mm; standard implants, 2.91 ± 0.35 mm) or mean marginal bone loss (short implants, 1.2 ± 1.21-mm mesially and 1.36 ± 1.47-mm distally; standard implants: 0.63 ± 0.80-mm mesially and 0.78 ± 0.70-mm distally).ConclusionsIn this study, the success rate of short dental implants was comparable to that of standard-sized implants. Consequently, it can be claimed that the long-term success of short dental implants does not differ significantly from the long-term success of standard implants.

Polyurethane Implants in Revisional Breast Augmentation: A Prospective 5-Year Study.

Revisional surgery for aesthetic breast augmentation remains a challenging procedure. Polyurethane (PU) implants have been found to avoid capsular contracture recurrence as well as to prevent implant displacement by bio-integrating with the pocket. Our study aimed to assess the use of PU implants in breast revisional surgery and to provide an algorithm. Over a 5-year period, a prospective study was conducted involving consecutive patients undergoing implant revision. Patient demographics, previous breast procedures, and specific surgical details were documented. Postoperative outcomes were followed up. Out of 92 patients (184 breasts), 78 (156 breasts) were included in the analysis. The average age was 47.5, with a BMI of 22.3 and a mean follow-up of 5 years. A majority (63%) represented secondary revisional cases, while 37% were tertiary cases. Implant size averaged 296 cc, with 53% placed in retropectoral position and 47% prepectoral. Significantly more implants in secondary cases were changed from prepectoral to retropectoral (P = .005), and in tertiary changed from retropectoral to prepectoral (P = .002). Complete capsulectomy was performed in 61.5% and partial in 25.6%. Additional lipofilling was performed in 32%, and concurrent mastopexy in 40%. Revisional surgery in our series had a 1.9% acute complication rate, 4.5% longer-term reoperation rate for corrections, 0.6% implant exchange rate, and no recurrent capsular contracture. This is the first study to provide data on outcomes of revisional breast augmentation surgery with PU implants. It shows that polyurethane implants offer consistent stability and have low rates of recurrent capsular contracture in revisional surgery.

Impact of Implant Size and Position on Subsidence Degree after Anterior Cervical Discectomy and Fusion: Radiological and Clinical Analysis.

Implant subsidence is recognized as a complication of interbody stabilization, although its relevance remains ambiguous, particularly in terms of relating the effect of the position and depth of subsidence on the clinical outcome of the procedure. This study aimed to evaluate how implant positioning and size influence the incidence and degree of subsidence and to examine their implications for clinical outcomes. An observational study of 94 patients (157 levels) who underwent ACDF was conducted. Radiological parameters (implant position, implant height, vertebral body height, segmental height and intervertebral height) were assessed. Clinical outcomes were evaluated using the Visual Analogue Scale (VAS) and Neck Disability Index (NDI). Subsidence was evaluated in groups according to its degree, and statistical analyses were performed. The findings revealed that implant-to-endplate ratio and implant height were significant risk factors associated with the incidence and degree of subsidence. The incidence of subsidence varied as follows: 34 cases (41.5%) exhibited displacement of the implant into the adjacent endplate by 2-3 mm, 32 cases (39%) by 3-4 mm, 16 cases (19.5%) by ≥4 mm and 75 (47.8%) cases exhibited no subsidence. The findings underscore that oversized or undersized implants relative to the disc space or endplate length elevate the risk and severity of subsidence.

Clinical decision support system based on deep learning for evaluating implantable collamer lens size and vault after implantable collamer lens surgery: a retrospective study

ObjectivesTo aid doctors in selecting the optimal preoperative implantable collamer lens (ICL) size and to enhance the safety and surgical outcomes of ICL procedures, a clinical decision support system (CDSS)...

Neural Dielet 2.0: A 128-Channel 2mm×2mm Battery-Free Neural Dielet Merging Simultaneous Multi-Channel Transmission through Multi-Carrier Orthogonal Backscatter.

Miniaturization of wireless neural-recording systems enables minimally-invasive surgery and alleviates the rejection reactions for implanted brain-computer interface (BCI) applications. Simultaneous massive-channel recording capability is essential to investigate the behaviors and inter-connections in billions of neurons. In recent years, battery-free techniques based on wireless power transfer (WPT) and backscatter communication have reduced the sizes of neural-recording implants by battery eliminating and antenna sharing. However, the existing battery-free chips realize the multi-channel merging in the signal-acquisition circuits, which leads to large chip area, signal attenuation, insufficient channel number or low bandwidth, etc. In this work, we demonstrate a 2mm×2mm battery-free neural dielet, which merges 128 channels in the wireless part. The neural dielet is fabricated with 65nm CMOS process, and measured results show that: 1) The proposed multi-carrier orthogonal backscatter technique achieves a high data rate of 20.16Mb/s and an energy efficiency of 0.8pJ/bit. 2) A self-calibrated direct digital converter (SC-DDC) is proposed to fit the 128 channels in the 2mm×2mm die, and then the all-digital implementation achieves 0.02mm2 area and 9.87μW power per channel.

Minimally Invasive Direct Aortic Implantation of Impella 5.5 As Bridge to Transplant: A Case Report

The use of temporary mechanical circulatory support (t-MCS) in cardiogenic shock (CS) is increasing.The Impella (Abiomed) is a percutaneous, microaxial ventricular assist device approved for short-term use in CS that can be implanted peripherally. Direct aortic placement is an alternative commonly performed when the sternum is open, for example, in post-cardiotomy shock, or when the peripheral vasculature is of insufficient size or quality for implantation. Herein we describe direct aortic implantation of the Impella 5.5 via right mini-thoracotomy for a patient in CS secondary to decompensated heart failure as a bridge to candidacy, and ultimately, transplantation.

From inception to innovation: bibliometric analysis of the evolution, hotspots, and trends in implantable collamer lens surgery research.

As one of several refractive surgeries, Implant Collamer Lens (ICL) surgery offers stable biocompatibility and consistent, high-quality visual outcomes. ICL has become an effective complement to corneal refractive surgery, gradually becoming one of the mainstream methods for correcting refractive errors. This study employs bibliometric methods to analyze research on ICL surgery to understand the progress, hotspots, and potential future trends in this field. This study performed a bibliometric analysis of all ICL-related articles collected from the Web of Science Core Collection database between January 1st, 1996, and December 31st, 2023. The CiteSpace 6.2.R4 tool, Excel and the Web of Science website were used to analyze data by country, institution, keywords, and clusters of keywords. Additionally, an in-depth interpretation and analysis were conducted on the field's high-impact articles. Since the first clinical application report of ICL, there have been a total of 875 studies. The number of papers published annually has shown an overall increasing trend. Studies published from China are the most numerous, accounting for 29.14% (n = 255) of the total. Among the institutions, Fudan University and Kitasato University both have published more than 50 papers, with Kitasato University having the highest H-index of 26. The journals with the top 10 publication volumes are all specialized in ophthalmology. The burst keywords since the introduction of ICL surgery have been "intraocular lens," "refractive surgery," and "cataract surgery." The current burst keywords include "visual quality," "vector analysis," "axial length," etc. The results of keyword clustering included ICL, pIOL, high myopia, axial length, optical quality, refractive surgery, ICL implantation, and pupil size. In the High-impact Articles, it was found that the high-impact articles predominantly focus on the safety, efficacy, and predictability of ICL surgery. Research on ICL has grown since its clinical introduction, with the advent of the central hole ICL sparking a surge in recent hotspots, particularly in China. Current hotpots in the field of ICL surgery are "visual quality," "ICL implantation," "vector analysis," "axial length," "evo ICL," "ICL v4c," and "ICL." ICL surgery research trends have evolved from implantation techniques to biological parameters associated with ICL surgery and the benefits of new ICL designs.