Search

Purpose: This study aimed to assess the diagnostic accuracy of smartphone photographs, taken at the emergency department (ED) and shared with hand surgeons, in identifying critical circulatory issues and neurovascular bundle injury, as well as tendon and bone injuries., Methods: The photographs of hand injuries of 50 patients who were referred to our ED between January 2020 and January 2022 were used to design a questionnaire. This questionnaire, including closed-ended questions about the injured structures, was shared with a group of hand surgeons via a WhatsApp group in Turkey. The experience levels of the surgeons were categorized as 0-5 years, 5-10 years, and above 10 years. Diagnostic accuracy was assessed by comparing the results with surgery notes as the reference standard., Results: A total of 94 hand surgeons participated in the study. The accuracy of predicting critical circulatory issues in the hand/fingers from the smartphone photographs was 81.9%, with a sensitivity of 48.0% and a specificity of 91.4%. For neurovascular bundle injuries, the accuracy was 63.0%, with a sensitivity of 63.9% and a specificity of 61.5%. The accuracy of predicting tendon injuries was 64.9%, with a sensitivity of 81.1% and a specificity of 42.5%. The accuracy of predicting fracture was 74.7%, with a sensitivity of 70.9% and a specificity of 79.9%., Conclusions: Identifying critical circulatory issues solely based on the shared photograph is inadequate. Similarly, evaluation based only on the photograph was insufficient for the detection of neurovascular bundle injuries, tendon ruptures, and fractures., Clinical Relevance: Digital images acquired in an ED setting and subsequent review of these images by hand surgeons may not be an adequately reliable strategy for determining the necessity of patient transfer., Competing Interests: Conflicts of Interest No benefits in any form have been received or will be received related directly to this article., (Copyright © 2024 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)

This paper proposes a smartphone-based method for measuring Blood Pressure (BP) using the oscillometric method. For oscillometry, it is necessary to measure (1) the pressure applied to the artery and (2) the local blood volume change. This is accomplished by performing an oscillometric measurement at the finger's digital artery, whereby a user presses down on the phone's camera with steadily increasing force. The camera is used to capture the blood volume change using photoplethysmography. We devised a novel method for measuring the force applied of the finger without the use of specialized smartphone hardware with a technique called Vibrometric Force Estimation (VFE). The fundamental concept of VFE relies on a phenomenon where a vibrating object is dampened when an external force is applied on to it. This phenomenon can be recreated using the phone's own vibration motor and measured using the phone's Inertial Measurement Unit (IMU). A cross device reliability study with three smartphones of different manufacturers, shape, and prices results in similar force estimation performance across all smartphone models. In an N = 24 proof of concept study of the BP measurement, the smartphone technique achieves a mean absolute error of 9.21 mmHg and 7.77 mmHg of systolic and diastolic BP, respectively, compared to an FDA approved BP cuff. The vision for this technology is not necessarily to replace existing BP monitoring solutions, but rather to introduce a downloadable smartphone software application that could serve as a low-barrier hypertension screening measurement fit for widespread adoption., (© 2024. The Author(s).)

Objective: To investigate the anatomical basis and clinical efficiency of the advancement distance in dorsal digital V-Y advancement flap., Materials and Methods: Thirty-four fingers in 11 fresh adult hand specimen were selected, V-Y flap was performed with the digital artery as vascular pedicle, and the advancement distance was measured. The relationship between the distance and extensibility of skin, sliding degree of subcutaneous superficial fascia, angular displacement of digital arterial dorsal branch, elasticity of digital artery was discussed. Two cases were provided to demonstrate the feasibility and importance of this flap., Results: In the dorsal digital V-Y advancement flap simulated on fresh adult hand specimens, the mean advance distance of the middle segment flap and proximal segment flap is 18 ± 0.8 mm and 34 ± 1.7 mm, respectively, and the maximum can reach 24 and 45 mm, respectively. Two cases of dorsal digital V-Y advancement flaps were designed and performed in the dorsal side of the ring finger middle segment and the thumb proximal segment, respectively. The advancement distances were 25 and 26 mm, respectively. All flaps survived completely and the incisions healed by first intention. The flap texture was good, the affected finger was symmetrical, and the activity and sensation restored well., Conclusion: The dorsal digital V-Y advancement flap with the digital artery as the main vascular pedicle can exert four factors for advancement effect, and significantly increase the advancement distance. The operation is simple, the blood supply is reliable, and the postoperative sensation is normal. It is an ideal flap for repairing the digital dorsal defect.

Objective: The purpose of this study is to compare the results of the innervated digital artery perforator (IDAP) flap and the direct-flow homodigital flap as reconstruction methods for fingertip soft tissue amputations. This issue is important in hand surgery, and we aim to identify the method that provides the best functional and cosmetic outcomes., Methods: Between 2020 and 2022, 32 patients with fingertip amputations were reconstructed by the same surgeon using two different methods. The patients were retrospectively divided into two groups: those who underwent IDAP (n = 14) and those who had a direct-flow homodigital flap (n = 18). We compared the groups in terms of defect size, cold intolerance, venous congestion, Sollerman hand function test scores, Seddon sensory test scores, and follow-up periods, as well as flap viability, flexion contracture, and static two-point discrimination (s2PD)., Results: Of the 32 patients (26 men, 6 females; age: mean 28.72 ± 11.5 years), the injuries were caused by different mechanisms, including sharp (57.1% IDAP), crush (75% IDAP) and entanglement (66.7% homodigital). The average area of tissue loss was approximately 2.70 ± 1.37 cm², while the average s2PD measurement was approximately 4.94 ± 1.04 mm. Postoperatively, the Seddon sensory test results for the homodigital flap group were S4 (61.5%), S3 (23.1%), S3+ (7.7%), and S2 (7.7%), compared to the IDAP group, which showed S4 (57.9%), S3+ (21.1%), and S3 (21.1%). Complications occurred in five patients, though no flap loss or revision was required. The postoperative mean Sollerman hand function scores were higher for the homodigital group than for the IDAP group, with values of 75 ± 2.64 and 73 ± 3.34, respectively. Although not statistically significant, the results numerically suggest that the IDAP flap is better in terms of sensory recovery and hand function compared to the homodigital flap (p > 0.05)., Conclusions: This is the first investigation to compare direct-flow flaps with IDAP. The average follow-up period for patients who underwent homodigital surgery was also shorter than that of the IDAP group. Furthermore, the mean postoperative two-point discrimination and postoperative Sollerman function score were higher in patients who had homodigital surgery., (© 2024. The Author(s).)

Objective: To assess the changes in blood vessel stiffness and digital pulse wave amplitude because of flowmediated dilatation, and to explore how these two variables change when endothelial dysfunction is experimentally induced., Methods: The experimental study was conducted at the departments of physiology at the College of Medicine, Mustansiriyah University, and the College of Medicine, Al-Iraqia University, Baghdad, Iraq, from October 14, 2021, to May 31, 2022, and comprised healthy young males who were subjected to the flow-mediated dilatation technique on the left brachial artery. Pulse transit time and the amplitude of the digital pulse wave were measured during reactive hyperaemia for 2.5 minutes from the left middle finger using a piezoelectric pressure sensor and a simultaneous Lead I electrocardiogram. Endothelial dysfunction (ED) was induced by oscillatory and retrograde shear rates. The correlation between variables was calculated in Excel running on the Windows operating system., Results: There were 10 second-year medical students with mean age 22±0 years and mean body mass index 25.7±4.8kg/m2. During reactive hyperaemia, pulse transit time was significantly increased by 3-5% in both normal endothelium and experimentally induced endothelial dysfunction relative to the pre-occluded artery, and the difference was not significant (p>0.05). Digital pulse wave amplitude increased significantly in normal endothelium relative to the pre-occluded artery (p<0.05), but not in experimentally-induced endothelial dysfunction (p>0.05)., Conclusions: The pulse transit time and digital pulse wave amplitudes of the photo plethysmography signal may be used to detect changes in vessel wall diameter and tone throughout the reactive hyperaemia process. Digital pulse wave amplitude was better able to detect experimentally-induced endothelial dysfunction, as assessed by the flowmediated dilatation protocol, than pulse transit time.

Study Objectives: Advanced signal processing of photoplethysmographic data enables novel analyses which may improve the understanding of the pathogenesis of dysglycemia associated with sleep disorders. We aimed to identify sleep-related pulse wave characteristics in diabetic patients compared to normoglycemic individuals, independent of cardiovascular-related comorbidities., Methods: This cross-sectional evaluation of the population-based Swedish CArdioPulmonary bioImage Study (SCAPIS) included overnight oximetry-derived pulse wave data from 3997 subjects (45 % males, age 50-64 years). Metabolic status was classified as normoglycemic (n = 3220), pre-diabetic (n = 544), or diabetic (n = 233). Nine validated pulse wave features proposed to influence cardiovascular risk were derived and compared between metabolic status groups. Logistic prediction models and genetic matching were applied to capture diabetes-related pulse wave characteristics during sleep. The model was controlled for anthropometrics, lifestyle, sleep apnea, and in the final adjustment even for cardiometabolic factors like dyslipidaemia, hypertension, and coronary artery calcification., Results: Pulse wave-derived parameters differed between normoglycemic and diabetic individuals in eight dimensions in unadjusted as well as in the partially adjusted model (anthropometric factors and sleep apnea, p ≤ 0.001). All covariates confirmed significant differences between normoglycemic and diabetic subjects (all p ≤ 0.001). Reduced cardio-respiratory coupling (respiratory-related pulse oscillations) (β = -0.010, p = 0.012), as well as increased vascular stiffness (shortened pulse propagation time (β = -0.015, p = 0.001), were independently associated with diabetes even when controlled for cardiometabolic factors. These results were confirmed through a matched cohort comparative analysis., Conclusions: Photoplethysmographic pulse wave analysis during sleep can be utilized to capture multiple features of modified autonomic regulation and cardiovascular consequences in diabetic subjects. Dampened heart rate variability and increased vascular stiffness during sleep showed the strongest associations with diabetes., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Ludger Grote reports a relationship with ResMed, Phillips, Astra Zeneca, Lundbeck, and Itamar that includes: speaking and lecture fees. Ludger Grote and Jan Hedner report a relationship with Bayer on behalf of the ESADA network that includes: funding grants. Ludger Grote reports a relationship with Onera that includes: consulting or advisory. Jan Hedner reports a relationship with SomnoMed that includes: consulting or advisory. Ludger Grote and Jan Hedner have patent #10617694 - Sultiame for the treatment of sleep apnea licensed to Desitin Arzneimittel GmbH. Jan Hedner is an Associate Editor of Sleep Medicine. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: The use of a self-adherent, elastic bandage is a practical way to dress finger injuries. Multiple reports describe iatrogenic injuries from elastic bandages, ranging from skin necrosis to finger gangrene, necessitating amputations. This study investigated whether elastic bandages can compromise digital perfusion by occluding arterial blood flow in healthy volunteers and evaluated the utility of pulse oximetry as a monitoring tool for digital perfusion. A technique for safe bandage application is proposed., Methods: A commercially available elastic bandage was wrapped around the index finger of 20 healthy volunteers at varying degrees of stretch. Digital perfusion measurements were carried out using photoelectric pulse transduction, laser Doppler flowmetry, and pulse oximetry. Intracompartmental pressure measurements were recorded using a separate in vitro experimental model., Results: Elastic bandages applied at maximum stretch did not change digital brachial index or pulse oximetry values, suggesting arterial blood flow was preserved distal to the bandage. Intracompartmental pressure measurements at maximum stretch remained below the systolic digital pressure. In contrast, superficial dermal perfusion fell to 32% of normal as measured by laser Doppler flow, at 100% bandage stretch., Conclusion: This study suggests a risk for iatrogenic injury when using elastic bandages for finger dressings. While arterial inflow was never compromised, pressures were high enough to occlude superficial venous outflow, which may begin at 20% bandage stretch. Pulse oximetry failed to detect changes distal to applied dressings, and we do not recommend it to detect digital vascular compromise in this setting., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Purpose: Exposure to cold temperatures decreases finger temperature (T fing ) and dexterity. Decreased manual function and dexterity can be serious safety risks, especially in tasks that require fine motor movements that must be performed outdoors. The aim of this study was to determine whether hand heating with a minimal power requirement (14.8 W) results in a smaller reduction in T fing and manual dexterity performance during mild cold exposure compared to a non-heated control condition., Methods: In a randomized crossover design, twenty-two healthy participants were exposed to a moderately cold environment (5  ºC) for 90 min. One condition had no intervention (CON), while the other had the palmar and dorsal hands heated (HEAT) by using electric heating films. T fing and cutaneous vascular conductance (CVC) were continuously monitored using laser Doppler flowmetry. Manual dexterity performance and cognitive function were assessed by the Grooved Pegboard Test (GPT) and Stroop Color-Word (SCW) test, respectively, during the baseline period and every 30 min during the cold exposure., Results: After the cold exposure, T fing was higher in HEAT relative to CON (CON 9.8 vs. HEAT 13.7 ºC, p < 0.0001). GPT placing time, as an index of dexterity performance, was also shorter in HEAT by 14.5% (CON 69.10 ± 13.08 vs. HEAT 59.06 ± 7.99 s, p < 0.0001). There was no difference in CVC between the two conditions during the cold exposure (p > 0.05 for all). Cognitive function was similar between two conditions (p > 0.05 for all)., Conclusion: The proposed hand heating method offers a practical means of heating fingers to maintain dexterity throughout prolonged cold exposure., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Competing Interests: Competing interests:: None declared.

Finger vein (FV) biometrics have garnered considerable attention due to their inherent non-contact nature and high security, exhibiting tremendous potential in identity authentication and beyond. Nevertheless, challenges pertaining to the scarcity of training data and inconsistent image quality continue to impede the effectiveness of finger vein recognition (FVR) systems. To tackle these challenges, we introduce the visual feature-guided diamond convolutional network (dubbed 'VF-DCN'), a uniquely configured multi-scale and multi-orientation convolutional neural network. The VF-DCN showcases three pivotal innovations: Firstly, it meticulously tunes the convolutional kernels through multi-scale Log-Gabor filters. Secondly, it implements a distinctive diamond-shaped convolutional kernel architecture inspired by human visual perception. This design intelligently allocates more orientational filters to medium scales, which inherently carry richer information. In contrast, at extreme scales, the use of orientational filters is minimized to simulate the natural blurring of objects at extreme focal lengths. Thirdly, the network boasts a deliberate three-layer configuration and fully unsupervised training process, prioritizing simplicity and optimal performance. Extensive experiments are conducted on four FV databases, including MMCBNU&#95;6000, FV&#95;USM, HKPU, and ZSC&#95;FV. The experimental results reveal that VF-DCN achieves remarkable improvement with equal error rates (EERs) of 0.17%, 0.19%, 2.11%, and 0.65%, respectively, and Accuracy Rates (ACC) of 100%, 99.97%, 98.92%, and 99.36%, respectively. These results indicate that, compared with some existing FVR approaches, the proposed VF-DCN not only achieves notable recognition accuracy but also shows fewer number of parameters and lower model complexity. Moreover, VF-DCN exhibits superior robustness across diverse FV databases.

Background: Pregnancy complications related to hypertension can affect both mother and newborn. Pulse wave attenuation (PWA) captured through fingertip photoplethysmography (PPG) provide valuable insights into maternal acute hemodynamic and autonomic vascular function. Here, we quantify the nocturnal dynamics of PWA during early pregnancy and assess their association with the development of gestational hypertension, preeclampsia and gestational diabetes., Methods: PWA dynamics were assessed on overnight polysomnography-derived PPG signals from a cohort of 2714 pregnant women (mean age: 26.8 ± 5.5 years) enrolled in the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b). We determined the average duration (PWA duration ) and depth (PWA depth ) of PWA events in all women., Results: Odds ratio (OR) analysis-adjusted common confounders indicates that an average PWA duration greater than 8.74 s was associated with the increased risk of gestational hypertension [OR = 1.75 (1.27-2.39), P  < 0.001]. Similarly, average PWA depth greater than 1.19 was associated with an increased risk of preeclampsia [OR = 1.53 (1.01-2.33), P  = 0.045] and gestational diabetes [OR = 1.66 (1.01-2.73), P  = 0.044]., Conclusion: PWA attenuation dynamics during early pregnancy predict the risk of developing gestational hypertension and diabetes condition for women in their later trimesters. Potentially obtainable from smart wearable consumer devices, PWA analysis offers a low-cost, accessible and scalable marker that can enhance the management of pregnancy-induced cardiometabolic issues., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Introduction: Despite the progress in microsurgery in recent decades, neurovascular bundle defects during ring finger injuries still pose challenges for the surgeon. Usually, a reversed venous graft and a non-vascularized nerve graft are utilized to reconstruct this defect. One of the most common challenges encountered when using a venous graft is the caliber mismatch between the graft and the digital arterial ends. The use of an arterialized nerve graft (neurovascular graft) is poorly described and could represent an attractive reconstructive option., Case Presentation: We present the case of a 36-year-old manual worker, a non-smoker, with no significant medical or surgical comorbidities, who presented a ring avulsion type trauma, leading to the amputation of the third left finger at the distal interphalangeal joint and avulsion of the circumferential skin at the level of the middle and proximal phalanges (Urbaniak III). The patient presented a neurovascular bundle defect of 3 cm, reconstructed by the vascularized posterior interosseous nerve graft along the distal perforator of the dorsal branch of the anterior interosseous artery serving both as an interpositional arterial conduit and as a nerve graft. The results of postoperative nerve regeneration at three years are satisfactory, with the patient demonstrating a two-point discrimination measured at 6 mm., Conclusion: Simultaneous digital artery and nerve reconstruction using a neurovascular flap is very appealing to the hand surgeon as it offers several advantages over traditional methods, particularly the ideal diameter match between the digital arteries and the distal perforator of the dorsal branch of the anterior interosseous artery., (Copyright © 2024 SFCM. Published by Elsevier Masson SAS. All rights reserved.)

Background: Poor glycemic management persists among people practicing insulin therapy in relation to type 1 and 2 diabetes despite a clear relationship with negative health outcomes. Skin penetration by jet injection has recently been shown as a viable method for inducing blood release from fingertips. This study examines the use of vacuum to enhance the volume of blood released and quantifies any dilution of the collected blood., Methods: A single-blind crossover study involving 15 participants, each receiving four different interventions, was conducted wherein each participant served as their own control. Each participant experienced fingertip lancing and fingertip jet injection, both with and without applied vacuum. Participants were divided into three equal groups to explore different vacuum pressures., Results: This study found that glucose concentration in blood collected under vacuum following jet injection and lancing were equivalent. We found that applying a 40 kPa vacuum following jet injection produced a 35-fold increase in the collected volume. We determined the limited extent to which the injectate dilutes blood collected following jet injection. The mean dilution of blood collected by jet injection was 5.5%. We show that jet injection is as acceptable to patients as lancing, while being equally suited for conducting glucose measurements., Conclusions: Vacuum significantly enhances the volume of capillary blood released from the fingertip without any difference in pain. The blood collected by jet injection with vacuum is equivalent to that from lancing for glucose measurement purposes., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: A.T. has a minority interest in medical device company Portal Instruments, Inc.

Objective: Oscillometric finger pressing is a smartphone-based blood pressure (BP) monitoring method. Finger photoplethysmography (PPG) oscillations and pressure are measured during a steady increase in finger pressure, and an algorithm computes systolic BP (SP) and diastolic BP (DP) from the measurements. The objective was to assess the impact of finger artery viscoelasticity on the BP computation., Methods: Nonlinear viscoelastic models relating transmural pressure (finger BP - applied pressure) to PPG oscillations during finger pressing were developed. The output of each model to a measured transmural pressure input was fitted to measured PPG oscillations from 15 participants. A parametric sensitivity analysis was performed via model simulations to elucidate the viscoelastic effect on the derivative-based BP computation algorithm., Results: A Wiener viscoelastic model comprising a first-order transfer function followed by a static sigmoidal function fitted the measured PPG oscillations better than an elastic model containing only the static function (median (IQR) error of 30.5% (25.6%-34.0%) vs 50.9% (46.7%-53.7%); p<0.01). In Wiener model simulations, the derivative algorithm underestimated SP, especially with high pulse pressure and low transfer function cutoff frequency (i.e., greater viscoelasticity). The mean of the normalized PPG waveform at the maximum oscillation beat was found to correlate with the cutoff frequency (r = -0.8) and could thus possibly be used to compensate for viscoelasticity., Conclusion: Finger artery viscoelasticity negatively impacts oscillometric BP computation algorithms but can potentially be compensated for using available measurements., Significance: These findings may help in converting smartphones into truly cuffless BP monitors for improving hypertension awareness and control.

Objective: The decline in vascular elasticity with aging can be manifested in the shape of pulse wave. The study investigated the pulse wave features that are sensitive to age and the pattern of these features change with increasing age were examined., Methods: Five features were proposed and extracted from the photoplethysmography (PPG)-based pulse wave or its first derivative wave. The correlation between these PPG features and ages was studied in 100 healthy subjects with a wide range of ages (20-71 years). Piecewise regression coefficients were calculated to examine the rates of change of the PPG features with age at different age stages., Results: The proposed PPG features obtained from the finger showed a strong and significant correlation with age (with r = 0.76 - 0.77, p < 0.01), indicating higher sensitivity to age changes compared to the PPG features reported in previous studies (with r = 0.66 - 0.75). The correlation remained significant even after correcting for other clinical variables. The rate of change of the PPG feature values was found to be significantly faster in subjects aged ≥40 years compared to those aged < 40 years in the healthy population. This rate of change was similar to the age-related progression of arterial stiffness evaluated by pulse wave velocity (PWV), which is considered a gold standard for evaluating vascular stiffness., Conclusions: The proposed PPG features showed a high correlation with chronological age in healthy subjects and exhibited a similar age-related change trend as PWV., Significance: With the convenience of PPG measures, the proposed age-related features have the potential to be used as biomarkers for vascular aging and estimating the risk of cardiovascular disease.

Background: Systemic sclerosis (SSc) is a complex autoimmune connective-tissue disease, characterised by vasculopathy and fibrosis of the skin and internal organs. Activation of microvascular endothelial cells (ECs) causes the intimal hyperplasia that characterises the vascular remodelling in SSc. The most frequent complication of SSc is the development of digital ulcers (DUs). Thymic stromal lymphopoietin (TSLP) may trigger fibrosis and sustain vascular damage. Aim of this study was to evaluate the correlation between serum level of TSLP and DUs., Methods: 75 consecutive SSc patients were enrolled and serum TSLP levels were measured. The presence of history of DUs (HDU) was evaluated. Recurrent new DUs were defined as the presence of at least 3 episodes of DUs in a 12-months follow up period. The risk of developing new DUs was calculated by applying the capillaroscopic skin ulcer risk index (CSURI)., Results: The median value of TSLP was higher in patients with HDU than patients without HDU [181.67 pg/ml (IQR 144.67; 265.66) vs 154.67 pg/ml (IQR 110.67; 171.33), p < 0.01]. The median value of TSLP was higher in patients with an increased CSURI index than patients without an increased CSURI [188 pg/ml (IQR 171.33; 246.33) vs 159.33 pg/ml (IQR 128.67; 218), p < 0.01]. Kaplan-Meier curves demonstrated that free survival from new DUs was significantly (p < 0.01) lower in SSc patients with increased TSLP serum levels., Conclusion: TSLP might have a key role in digital microvascular damage of SSc patients., Competing Interests: Declaration of competing interest All the authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Fossati, Alexandre, and Aleid C. J. Ruijs. Changes in fingertip cold-induced vasodilatation (hunting reaction) on acute exposure to altitude. High Alt Med Biol . 25:212-217, 2024. Objective: Cold-induced vasodilation (CIVD) of the extremities is an interesting part of human physiology. Although the physiology of the CIVD reaction remains unknown, there are indications that hypoxia influences our CIVD reaction. The objective of this study is to measure the influence of acute hypoxia on the CIVD reaction of the fingertips. Methods: The CIVD reaction was measured using immersion of one hand in a water bath of 0°C in 12 healthy volunteers at low (1,235 m) and high (3,800 m) altitude during 35 minutes. High altitude was reached by a 20-minute cable car ride. Testing was performed indoors (room temperature, 22-25°C) at both altitudes. Data analysis was performed measuring the parameters of the CIVD reaction. Differences were found using the paired Student's t-test . Results: There was no significant difference in baseline finger temperature, onset time, peak time, and frequency of the CIVD reaction. However, at high altitude, maximum temperature and amplitude were significantly higher, slope was steeper, and minimum temperature was lower. Conclusion: We did not find evidence for a diminished CIVD reaction at high altitude due to hypoxia.

Objective: Raynaud phenomenon (RP) and digital ulcers (DUs) are the main signs of digital vasculopathy in systemic sclerosis (SSc). Selexipag is an oral prostacyclin agonist approved for SSc-related pulmonary arterial hypertension. Following our previous preliminary short-course report, we herein present long-term data on selexipag safety and efficacy in the treatment of SSc digital vasculopathy., Methods: Selexipag was administered to patients with SSc with severe digital vasculopathy refractory or with contraindication to all other vasoactive therapies. Each subject was assessed at baseline and after 3, 6, and 12 months. Clinical outcomes related to RP and DUs were evaluated along with modified Rodnan skin score of the fingers. Digital perfusion was assessed by laser speckle contrast analysis (LASCA). Nailfold videocapillaroscopy (NVC) was also performed., Results: Eight patients with SSc (63% female, mean age 50.1 years) received selexipag. After 12 months of treatment, RP was reported to significantly decrease in the number of daily episodes and mean duration ( P < 0.001 and P = 0.01, respectively). All patients achieved a complete healing of their DUs ( P = 0.03) within 6 months. A progressive reduction of fingers skin score was observed ( P = 0.03). No structural changes of capillaries were noted on NVC. Conversely, LASCA revealed an important increase in total digital perfusion ( P = 0.004) despite seasonal variability. The safety profile was consistent with that reported in the literature., Conclusion: We observed a sustained efficacy of selexipag on SSc digital vasculopathy during 1 year of administration. Our promising results encourage the design of a new randomized controlled trial to evaluate the effect of selexipag on SSc digital vasculopathy., (Copyright © 2024 by the Journal of Rheumatology.)

Overestimation of blood pressure (BP) resulting from medial artery calcification (MAC) is a cause of pseudoresistant hypertension. In this condition, there is no noninvasive way to reliably assess the BP. We report the case of a 62-year-old man who had a four-limb MAC, hypertension despite five antihypertensive molecules, and significant orthostatic hypotension following the addition of the fifth drug. Hypotension symptoms resolved after discontinuation of two treatments. Subsequently, measurement of finger SBP (FSBP) by laser Doppler flowmeter (LDF) was used to estimate upper-limb SBP. While the brachial SBP was greater than 170 mmHg, the FSBP was always less than 140 mmHg. In the absence of upper-limb artery disease, by evidencing the discrepancy between FSBP and brachial SBP, LDF-obtained FSBP could be a reliable tool to ascertain pseudohypertension and monitor the antihypertensive treatment., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Objectives: Early shock reversal is crucial to improve patient outcomes. Capillary refill time (CRT) is clinically important to identify and monitor shock in children but has issues with inconsistency. To minimize inconsistency, we evaluated a CRT monitoring system using an automated compression device. Our objective was to determine proper compression pressure in children., Methods: Clinician force for CRT was collected during manual CRT measurement as a reference for automated compression in a previous study (12.9 N, 95% confidence interval, 12.5-13.4; n = 454). An automated compression device with a soft inflation bladder was fitted with a force sensor. We evaluated the effectiveness of the automated pressure to eliminate pulsatile blood flow from the distal phalange. Median and variance of CRT analysis at each pressure was compared., Results: A comparison of pressures at 300 to 500 mm Hg on a simulated finger yielded a force of 5 to 10 N, and these pressures were subsequently used for automated compression for CRT. Automated compression was tested in 44 subjects (median age, 33 months; interquartile range [IQR], 14-56 months). At interim analysis of 17 subjects, there was significant difference in the waveform with residual pulsatile blood flow (9/50: 18% at 300 mm Hg, 5/50:10% at 400 mm Hg, 0/51: 0% at 500 mm Hg, P = 0.008). With subsequent enrollment of 27 subjects at 400 and 500 mm Hg, none had residual pulsatile blood flow. There was no difference in the CRT: median 1.8 (IQR, 1.06-2.875) in 400 mm Hg vs median 1.87 (IQR, 1.25-2.8325) in 500 mm Hg, P = 0.81. The variance of CRT was significantly larger in 400 mm Hg: 2.99 in 400 mm Hg vs. 1.35 in 500 mm Hg, P = 0.02, Levene's test. Intraclass correlation coefficient for automated CRT was 0.56 at 400 mm Hg and 0.78 at 500 mm Hg., Conclusions: Using clinician CRT measurement data, we determined either 400 or 500 mm Hg is an appropriate pressure for automated CRT, although 500 mm Hg demonstrates superior consistency., Competing Interests: The remaining authors have disclosed that they do not have any conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Reverse homodigital artery island flap (RHDI) has been reported to have some postoperative complications. Cross-finger reverse digital artery island flap (CRDI), which is harvested from an adjacent intact finger, has been used to decrease these complications. This study aimed to provide a review of the CRDI procedure and compare the clinical outcomes of CRDI with those of RHDI., Methods: RHDI has been performed for fingertip amputations with deficit of 1.5-2.5 cm before 2018, and CRDI has been performed since 2018. We assessed the functional and aesthetic outcomes, including finger length, nail deformity, finger motion, and Hand20 scores at the final follow-up., Results: We identified 22 patients who underwent RHDI and 10 patients who underwent CRDI. The mean follow-up period was 10.3 ± 5.3 months. The median time required for wound healing were 47.0 days (IQR: 34.3-55.8 days) and 34.5 days (IQR: 29.3-44.3 days) in RHDI and CRDI, respectively. The hook nail deformity occurred significantly more frequently in RHDI compared to that in CRDI (40.9% vs. 0.0%, p = 0.03). Flexion contracture of the proximal interphalangeal joint greater than 15º was found to be significantly more in RHDI than in CRDI (36.4% vs. 0.0%, p = 0.04). The median postoperative total active motion of the donor site in CRDI was 278º (IQR: 260-280º). The median postoperative Hand20 scores were similar between the two groups., Conclusion: CRDI was associated with superior clinical outcomes in terms of lower rates of postoperative flexion contracture and hook nail deformity, potentially making it a better option compared to RHDI., Competing Interests: Conflict of interest statement The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)

Introduction: There is limited literature on digital ischemia in systemic Lupus erythematosus (SLE). We report the prevalence, associations and outcome of digital infarcts and gangrene from the Indian SLE inception cohort (INSPIRE)., Methods: From the web-based database of INSPIRE, we extracted information for patients with 'Digital Infarct' and 'Digital gangrene' at enrolment into cohort, together considered as critical peripheral ischemia (CPI); all others were controls. We describe the associations of CPI with SLE clinical phenotype, autoantibodies, and disease activity at enrolment. We also report short term outcomes viz. Digital tissue loss and early mortality up to 6 months and recurrence of digital ischemic events in cases till date., Results: Of 2503 SLE patients enrolled into the INSPIRE cohort, we identified 75 (2.9%) patients with CPI, 72 (96%) women and 6 (8%) children. Of them, 55 (73.3%) had digital gangrene and 21 (28%) patients had digital infarcts. Majority of digital gangrene resulted in amputation distal to terminal phalanx (63.6%). Multivariable analysis showed that pulmonary hypertension AOR [6.34 (1.99, 20.2)], coexistent thrombosis AOR [27.8 (15.7, 48.7)], triple antiphospholipid antibody positivity AOR [5.36 (1.67, 16.9)] and the presence of anti-Scl-70-antibody AOR [5.59 (1.86, 16.7)] were more likely while patients with class 3 or 4 lupus nephritis AOR [0.37 (0.15, 0.95)] and anti-nucleosome antibodies AOR [0.47 (0.23, 0.99)] were less likely to be associated with CPI. SLEDAI and short-term mortality were similar between cases and controls., Conclusions: CPI occurred in a higher proportion (2.9%) of SLE patients in the INSPIRE cohort as compared to earlier reports. Both prothrombotic state and vasculopathy contribute to its occurrence., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Competing Interests: Declaration of Competing Interest The authors report no conflict of interest.

Objective: Patients with secondary RP show a wide range of symptoms depending on the condition of vascular structures. If the symptoms are localized to specific fingers and angiography reveals a discrete segment of occlusion of a proper digital artery, we perform proper digital artery reconstruction with an interposition vein graft. The objective of this study was to evaluate the results of the surgery in patients with chronic hand ischaemia., Methods: A retrospective chart review was performed on patients who underwent proper digital artery reconstruction. Each digit that underwent grafting was analysed separately. The results of surgical intervention and recurrence based on patient symptoms were evaluated. Cox proportional hazards regression models were used to identify independent risk factors associated with recurrence, and the Kaplan-Meier method was used to predict the 5-year recurrence-free rate., Results: A total of 79 digits from 57 patients were included in this study. The majority of patients demonstrated resolution of ischaemic pain and ulceration (97.5% and 95.3%, respectively). Recurrence occurred in 16 (20.3%) patients during the follow-up period. In two cases (2.5%) surgery had no effect. In the multivariate Cox regression analysis, smoking and concomitant periarterial sympathectomy were significant factors associated with recurrence. In the Kaplan-Meier analysis, the 5-year recurrence-free rate in the total study population was 69.3%., Conclusions: Digital artery reconstruction using an interposition vein graft is an effective procedure for improving ischaemic pain and ulceration in patients with RP. Smoking and concomitant periarterial sympathectomy were significantly associated with recurrence., (© The Author(s) 2023. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Finger vein recognition methods, as emerging biometric technologies, have attracted increasing attention in identity verification due to their high accuracy and live detection capabilities. However, as privacy protection awareness increases, traditional centralized finger vein recognition algorithms face privacy and security issues. Federated learning, a distributed training method that protects data privacy without sharing data across endpoints, is gradually being promoted and applied. Nevertheless, its performance is severely limited by heterogeneity among datasets. To address these issues, this paper proposes a dual-decoupling personalized federated learning framework for finger vein recognition (DDP-FedFV). The DDP-FedFV method combines generalization and personalization. In the first stage, the DDP-FedFV method implements a dual-decoupling mechanism involving model and feature decoupling to optimize feature representations and enhance the generalizability of the global model. In the second stage, the DDP-FedFV method implements a personalized weight aggregation method, federated personalization weight ratio reduction (FedPWRR), to optimize the parameter aggregation process based on data distribution information, thereby enhancing the personalization of the client models. To evaluate the performance of the DDP-FedFV method, theoretical analyses and experiments were conducted based on six public finger vein datasets. The experimental results indicate that the proposed algorithm outperforms centralized training models without increasing communication costs or privacy leakage risks.

Competing Interests: Declaration of interests We declare no competing interests.

This study was performed to analyze fingertip capillary blood sampling in pediatric patients using microcapillary blood collection tubes and microhematocrit tubes and to compare the blood cell analysis results obtained via these two blood collection methods. Finger capillary blood was collected from 110 outpatients using microcapillary blood collection tubes and microhematocrit tubes and complete blood count analysis was performed with a Sysmex XS-900i hematology analyzer and manual microscopy for blood cell morphology. Paired data was evaluated for agreement and bias using the microhematocrit samples as the reference group and the samples from the microcapillary blood collection tubes as the observation group. The two blood collection methods demonstrated good agreement for measuring red blood cell (RBC) parameters (i.e., RBC, Hb, Hct, MCV, MCH and MCHC), wherein the relative bias was > allowable total error (TEa) in 0.91%, 1.82%, 11.82%, 1.82%, 0.91% and 8.18% of the parameter measures, respectively. According to industry requirements, the proportion of samples meeting the acceptable bias level should be > 80%. Additionally, the estimated biases at each medical decision level were within clinically acceptable levels for RBC, Hb, Hct, and MCV. However, the proportion of WBC and PLT counts with relative bias > TEa was 25.45% and 35.45%, respectively. Furthermore, the relative bias of the WBC count at the medical decision level of 0.5 × 10 9 /L and that of the PLT counts at the medical decision levels of 10 × 10 9 /L and 50 × 10 9 /L were clinically significant. Bland-Altman analysis further showed a mean bias of 0.66 × 10 9 /L (95% LoA, - 0.79 to 2.11) for the WBC count and 39 × 10 9 /L (95% LoA, - 46 to 124) for the PLT count from the blood samples collected in the microcapillary blood collection tubes compared with the counts of those collected in the microhematocrit tubes. Neutrophil, monocyte, lymphocyte, eosinophil, and PLT counts increased significantly in the microcapillary blood collection tubes compared with those in the microhematocrit tubes, along with an elevated number of instrument false alarms (P < 0.05). The two capillary blood collection devices exhibit performance differences. Therefore, clinicians should pay attention to the variation in results caused by different blood collection methods., (© 2024. The Author(s).)

Objective: To perform a systematic literature review (SLR) aimed at evaluating the efficacy and safety of pharmacological and non-pharmacological treatments for Raynaud's phenomenon (RP) and digital ulcers (DU) in patients with systemic sclerosis (SSc) and other connective tissue diseases (CTD), in order to inform the Portuguese recommendations for managing RP and DU in these patients., Methods: A SLR was conducted until May 2022 to identify studies assessing the efficacy and safety of pharmacological and non-pharmacological interventions for RP and DU in SSc and other CTD. Eligible study designs included randomized controlled trials (RCTs), controlled clinical trials, and their extensions for assessing efficacy and safety of interventions. Observational studies with a comparator were included for evaluating the efficacy and safety of non-pharmacological interventions and safety of pharmacological interventions. The risk of bias of each study was assessed using standard tools., Results: Out of 71 publications meeting the inclusion criteria, 59 evaluated pharmacological and 12 non-pharmacological interventions. We found moderate quality evidence supporting the efficacy of calcium channel blockers, phosphodiesterase-5 inhibitors, and intravenous prostacyclin analogues in reducing RP frequency, severity, and duration. Intravenous iloprost had a small to moderate effect size in improving DU healing. Phosphodiesterase-5 inhibitors were effective in reducing total DU count, new DU occurrence, and enhancing DU healing. Bosentan effectively prevented new DU in SSc patients. No new safety concerns were associated with these treatments. The studies on non-pharmacological interventions were, in general, of low quality, and had a small sample size. Warming measures decreased frequency and duration of RP attacks; laser therapy improved RP-related outcomes; local oxygen-ozone therapy improved RP outcomes as an add-on therapy; bone marrow mononuclear cell implantation improved DU-associated pain; periarterial sympathectomy and vascular bypass reduced DU number and finger amputation risk., Conclusion: The available evidence supports the efficacy and safety of pharmacological interventions, namely nifedipine, sildenafil, iloprost, and bosentan in treating RP and DU in patients with SSc and other CTD. Scarce and low-quality evidence does support the use of some non-pharmacological interventions but with only a modest effect size. This SLR underscores the limited availability of high-quality evidence for determining the optimal treatment.

Background: Patients with coronavirus disease 2019 have a high incidence of thrombosis that decreases after recovery. When coronavirus disease 2019 is accompanied by diseases prone to thrombosis, risk of post-infection thrombotic events may increase., Case Presentation: We report a case of digital ischemic gangrene in a 24-year-old Chinese female with systemic lupus erythematosus after recovery from coronavirus disease 2019. The pathogenesis was related to clinical characteristics of systemic lupus erythematosus, hypercoagulability caused by coronavirus disease 2019, and second-hit due to viral infection., Conclusion: Patients with autoimmune diseases should remain alert to autoimmune system disorders induced by severe acute respiratory syndrome coronavirus 2 and other viruses. Treatment for these patients should be strictly standardized, and appropriate anticoagulation methods should be selected to prevent thrombosis., (© 2024. The Author(s).)

Significance: Pulsatile blood oxygen saturation ( SpO 2 ) via pulse oximetry is a valuable clinical metric for assessing oxygen delivery. Individual anatomical features, including skin tone, may affect current optical pulse oximetry methods., Aim: We developed an optical pulse oximetry method based on dual-ratio (DR) measurements to suppress individual anatomical confounds on SpO 2 ., Approach: We designed a DR-based finger pulse oximeter, hypothesizing that DR would suppress confounds from optical coupling and superficial tissue absorption. This method is tested using Monte Carlo simulations and in vivo experiments., Results: Different melanosome volume fractions in the epidermis, a surrogate for skin tone, cause changes in the recovered SpO 2 on the order of 1% in simulation and in vivo . Different heterogeneous pulsatile hemodynamics cause greater changes on the order of 10% in simulations. SpO 2 recovered with DR measurements showed less variability than the traditional single-distance (SD) transmission method., Conclusions: For the models and methods considered here, SpO 2 measurements are strongly impacted by heterogeneous pulsatile hemodynamics. This variability may be larger than the skin tone bias, which is a known confound in SpO 2 measurements. The partial suppression of variability in the SpO 2 recovered by DR suggests the promise of DR for pulse oximetry., (© 2024 The Authors.)

Significance: Our goal is to understand the root cause of reported oxygen saturation ( SpO 2 ) overestimation in heavily pigmented skin types to devise solutions toward enabling equity in pulse oximeter designs., Aim: We aim to gain theoretical insights into the effect of skin tone on SpO 2 - R curves using a three-dimensional, four-layer tissue model representing a finger., Approach: A finger tissue model, comprising the epidermis, dermis, two arteries, and a bone, was developed using a Monte Carlo-based approach in the MCmatlab software. Two skin tones-light and dark-were simulated by adjusting the absorption and scattering properties within the epidermal layer. Following this, SpO 2 - R curves were generated in various tissue configurations, including transmission and reflection modes using red and infrared wavelengths. In addition, the influence of source-detector (SD) separation distances on both light and dark skin tissue models was studied., Results: In transmission mode, SpO 2 - R curves did not deviate with changes in skin tones because both pulsatile and non-pulsatile terms experienced equal attenuation at red and infrared wavelengths. However, in reflection mode, measurable variations in SpO 2 - R curves were evident. This was due to differential attenuation of the red components, which resulted in a lower perfusion index at the red wavelength in darker skin. As the SD separation increased, the effect of skin tone on SpO 2 - R curves in reflection mode became less pronounced, with the largest SD separation exhibiting effects similar to those observed in transmission mode., Conclusions: Monte Carlo simulations have demonstrated that different light pathlengths within the tissue contribute to the overestimation of SpO 2 in people with darker skin in reflection mode pulse oximetry. Increasing the SD separation may mitigate the effect of skin tone on SpO 2 readings. These trends were not observed in transmission mode; however, further planned research using more complex models of the tissue is essential., (© 2024 The Authors.)

Background: Extended soft tissue defects of the fingers-irrespective of their origin-are challenging to treat. In cases of missing amputates or crush injuries, the options are often limited to further amputation, ray resection, or free tissue transplantation. The SISAP-flap was developed to add an extra option to treat finger avulsion injuries or otherwise extended soft tissue finger defects., Methods: Cadaveric SISAP-flaps were individually dissected, tested for arterial perfusion using red ink and radiopaque dye, and transposed into artificially created same-size defects. After introducing this flap in the clinic, which was partially successful in the first patient, we modified the flap to its definite design., Results: Average cadaver flap size ranges between 11 cm and 22 cm in length, allowing dorsal wrapping of the flap over the fingertip and way back to the palmar metacarpophalangeal-joint. The flap is based on the distal web space perforator, which is commonly used by a dorsal metacarpal artery flap and supercharged using an intercompartmental, supraretinacular artery. Donor sites were closed primarily with little tension. Application of the flap in the clinic resulted in satisfactory functional and esthetic outcomes., Conclusion: The SISAP-flap is a new option for the reconstruction of extended finger defects and should be added to the reconstructive surgeon's armamentarium of pedicled flaps, providing relatively short operating times and promising clinical outcomes., (Copyright © 2024 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)

Introduction: A common consideration for replantation success is the ischemia time following injury and the preservation temperature. A classic principle within the hand surgery community describes 12 hours of warm ischemia and 24 hours of cold ischemia as the upper limits for digit replantation; however, these limits are largely anecdotal and based on older studies. We aimed to compare survival data from the large body of literature to aid surgeons and all those involved in the replantation process in hopes of optimizing success rates., Methods: The PubMed database was queried on April 4th, 2023, for articles that included data on digit replantation survival in terms of temperature of preservation and ischemia time. All primary outcomes were analyzed with the Mantel-Haenszel method within a random effects model. Secondary outcomes were pooled and analyzed using the chi-square statistic. Statistical analysis and forest plot generation were completed with RevMan 5.4 software with odds ratios calculated within a 95% confidence interval., Results: Our meta-analysis identified that digits preserved in cold ischemia for over 12 hours had significantly higher odds of replantation success than the amputated digits replanted with 0-12 hours of warm ischemia time ( P ≤ 0.05). The odds of survival in the early (0-6 hours) replantation group were around 40% greater than the later (6-12 hours) replantation group ( P ≤ 0.05). Secondary outcomes that were associated with higher survival rates included a clean-cut amputation, increased venous and arterial anastomosis, a repair that did not require a vein graft, and replants performed in nonsmokers ( P ≤ 0.05)., Discussion: Overall, these findings suggest that when predicting digit replantation success, time is of the essence when the digit has yet to be preserved in a cold environment. This benefit, however, is almost completely diminished when the amputated digit is appropriately maintained in a cold environment soon after injury. In conclusion, our results suggest that there is potential for broadening the ischemia time limits for digit replant survival outlined in the literature, particularly for digits that have been stored correctly in cold ischemia., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: Though the finger is generally recommended for pulse oxygen saturation (SpO 2 ) monitoring site, its reliability may be compromised in conditions of poor peripheral perfusion. Therefore, we compared the performance of nasal septum SpO 2 monitoring with finger SpO 2 monitoring relative to simultaneous arterial oxygen saturation (SaO 2 ) monitoring in generally anesthetized patients., Methods: In 23 adult patients, comparisons of SpO 2 measured at the nasal septum and finger with simultaneous SaO 2 were made at four time points during the 90 min study period. A pulse oximetry monitoring failure was defined as a > 10 s continuous failure of in an adequate SpO 2 data acquisition. Core temperature as well as finger-tip and nasal septum temperatures were simultaneously measured at 10 min intervals., Results: A total of 92 sets of SpO 2 and SaO 2 measurements were obtained in 23 patients. The bias and precision for SpO 2  measured at the nasal septum were - 0.8 ± 1.3 (95% confidence interval: - 1.1 to - 0.6), which was similar to those for SpO 2  measured at the finger (- 0.6 ± 1.4; 95% confidence interval: - 0.9 to - 0.4) (p = 0.154). Finger-tip temperatures were consistently lower than other two temperatures at all time points (p < 0.05), reaching 33.5 ± 2.3 °C at 90 min after induction of anesthesia. While pulse oximetry monitoring failure did not occur for nasal septum probe, two cases of failure occurred for finger probe., Conclusions: Considering the higher stability to hypothermia with a similar accuracy, nasal septum pulse oximetry may be an attractive alternative to finger pulse oximetry. Trail registration This study was registered with Clinical Research Information Service (CRIS: https://cris.nih.go.kr/cris/en/ ; ref: KCT0008352)., (© 2024. The Author(s) under exclusive licence to Japanese Society of Anesthesiologists.)

Significance: Questions about the accuracy of pulse oximeters in measuring arterial oxygen saturation ( SpO 2 ) in individuals with darker skin pigmentation have resurfaced since the COVID-19 pandemic. This requires investigation to improve patient safety, clinical decision making, and research., Aim: We aim to use computational modeling to identify the potential causes of inaccuracy in SpO 2 measurement in individuals with dark skin and suggest practical solutions to minimize bias., Approach: An in silico model of the human finger was developed to explore how changing melanin concentration and arterial oxygen saturation ( SaO 2 ) affect pulse oximeter calibration algorithms using the Monte Carlo (MC) technique. The model generates calibration curves for Fitzpatrick skin types I, IV, and VI and an SaO 2 range between 70% and 100% in transmittance mode. SpO 2 was derived by inputting the computed ratio of ratios for light and dark skin into a widely used calibration algorithm equation to calculate bias ( SpO 2 - SaO 2 ). These were validated against an experimental study to suggest the validity of the Monte Carlo model. Further work included applying different multiplication factors to adjust the moderate and dark skin calibration curves relative to light skin., Results: Moderate and dark skin calibration curve equations were different from light skin, suggesting that a single algorithm may not be suitable for all skin types due to the varying behavior of light in different epidermal melanin concentrations, especially at 660 nm. The ratio between the mean bias in White and Black subjects in the cohort study was 6.6 and 5.47 for light and dark skin, respectively, from the Monte Carlo model. A linear multiplication factor of 1.23 and exponential factor of 1.8 were applied to moderate and dark skin calibration curves, resulting in similar alignment., Conclusions: This study underpins the careful re-assessment of pulse oximeter designs to minimize bias in SpO 2 measurements across diverse populations., (© 2024 The Authors.)

Objective: Local vibration can cause microcirculatory abnormalities such as blood stasis and symmetrical intermittent digital artery vasospasm. Finger SBP (FSBP) measurement is a potential way of assessing vascular components. This study aims to comprehensively investigate the relationship between the occurrence of the vibration-induced white finger (VWF) and changes in FSBP and then set the application value of FSBP measurements in the early diagnosis of VWF., Methods: All samples were judgmental sampling from one factory. Totally 50 patients with VWF were the case group, while 50 without occupational hand-transmitted vibration exposure were the control group. FSBP measurements and epidemiological feature investigations were taken., Results: There were significant reductions in FSBP level and %FSBP index at both 10 °C and 30 °C in fingers reported VWF ( P  < 0.05). The %FSBP abnormal rate of the index, ring and little finger in the VWF group was higher than the control (44.00% vs. 18.00%, 78.00% vs. 26.00%, 64.00% vs. 8.00%). The %FSBP of the ring and little finger had a relatively high application value (area under curve = 0.902, 0.737), while their standard regression coefficients were -0.23 and -0.412. The diagnostic cutoff value of the ring finger was 77.60%, while the sensitivity and specificity were 86.67%., Conclusion: FSBP measurements were proven helpful in monitoring and diagnosing VWF prospectively and proved to have great application value in our study. %FSBP of the ring finger was the appropriate diagnostic index in FSBP measurements, while its abnormal value could be set as 80.00%., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

This research aimed to investigate the effect of PI3K (phosphatidylinositol 3-kinase)/AKT (protein kinase B)/mTOR (mammalian target protein of rapamycin) signaling pathway-based clustering care combined with papaverine injection on vascular inflammation and vascular crisis after finger amputation and replantation. 100 patients admitted in General Hospital of Ningxia Medical University from April 2022 to December 2022 for replantation of severed fingers were selected and divided into a control group (n = 50) and an observation group (n = 50) using the randomized grouping principle. The control group received a papaverine injection and general nursing care, the observation group received a papaverine injection and clustered care. The pain score; constipation incidence; replantation finger survival rate; physician, nurse, and patient satisfaction; serum inflammatory factors; vascular crisis parameters; and occurrence of adverse reactions were compared between the two patient groups. Enzyme-linked immunosorbent assay was performed to detect PI3K, AKT, and mTOR protein concentrations in the venous blood of the two groups, and statistical analysis of the data was performed. On postoperative day 7, the pain score and incidence of constipation in the observation group were lower than those in the control group (P < 0.05); the survival rate of reimplanted fingers in the observation group was 88.00%, which was higher than that in the control group 80.00% (P < 0.05); the satisfaction of doctors, nurses, and patients in the observation group was higher than that in the control group; the concentrations of interleukin-1 (IL-1), tumor necrosis factor (TNF-α), blood flow resistance index (RI), and arterial pulsatility index (PI) in the observation group were lower than those in the control group, while the concentration of interleukin-10 (IL-10), vascular diameter, and Vm (mean blood flow velocity) were higher in the observation group than those in the control group; the differences were statistically significant (P < 0.05). The difference in the incidence of adverse reactions between the two groups was not statistically significant (P > 0.05). The concentrations of PI3K, AKT, and mTOR proteins in the observation group were higher than those in the control group (P < 0.05). The concentrations of PI3K, AKT, and mTOR proteins in the observation group were higher than those in the control group (P < 0.05). Overall, these findings suggest that clustered care combined with papaverine injection reduces vascular inflammatory symptoms and vascular crisis in the treatment of severed finger replantation through the PI3K/AKT/mTOR signaling pathway., (© 2023. The Author(s).)

Objective: The aim of the present study was to illustrate the (potential) diagnostic role of high resolution US images in assessing the elementary lesions of dactylitis., Methods: Using high-frequency US machines/probes, we matched the micro-anatomical cadaveric architecture of the digit with multiple sonographic findings of dactylitis. High-sensitive color/power Doppler assessments have also been performed to evaluate the digital microvasculature., Discussion: Modern US equipment/features guarantee prompt and in-depth B-mode and color/power Doppler imaging of tiny anatomical structures of the digit which are usually not properly visible with standard US machines. More specifically, hypervascularization of the digital subcutaneous tissue, fibrous pulleys of flexor tendons, dorsal synovial pads as well as pathological changes of the distal entheseal anchorage network can be accurately detected., Conclusion: In clinical practice, high-end US equipment can be used to accurately assess the digits in patients with dactylitis. This way, simple and convenient sonographic diagnosis of different elementary lesions can be timely established., (© 2023. Società Italiana di Ultrasonologia in Medicina e Biologia (SIUMB).)

Objective. Diagnosis of incipient acute hypovolemia is challenging as vital signs are typically normal and patients remain asymptomatic at early stages. The early identification of this entity would affect patients' outcome if physicians were able to treat it precociously. Thus, the development of a noninvasive, continuous bedside monitoring tool to detect occult hypovolemia before patients become hemodynamically unstable is clinically relevant. We hypothesize that pulse oximeter's alternant (AC) and continuous (DC) components of the infrared light are sensitive to acute and small changes in patient's volemia. We aimed to test this hypothesis in a cohort of healthy blood donors as a model of slight hypovolemia. Approach. We planned to prospectively study blood donor volunteers removing 450 ml of blood in supine position. Noninvasive arterial blood pressure, heart rate, and finger pulse oximetry were recorded. Data was analyzed before donation, after donation and during blood auto-transfusion generated by the passive leg-rising (PLR) maneuver. Main results. Sixty-six volunteers (44% women) accomplished the protocol successfully. No clinical symptoms of hypovolemia, arterial hypotension (systolic pressure < 90 mmHg), brady-tachycardia (heart rate <60 and >100 beats-per-minute) or hypoxemia (SpO 2 < 90%) were observed during donation. The AC signal before donation (median 0.21 and interquartile range 0.17 a.u.) increased after donation [0.26(0.19) a.u; p < 0.001]. The DC signal before donation [94.05(3.63) a.u] increased after blood extraction [94.65(3.49) a.u; p < 0.001]. When the legs' blood was auto-transfused during the PLR, the AC [0.21(0.13) a.u.; p = 0.54] and the DC [94.25(3.94) a.u.; p = 0.19] returned to pre-donation levels. Significance. The AC and DC components of finger pulse oximetry changed during blood donation in asymptomatic volunteers. The continuous monitoring of these signals could be helpful in detecting occult acute hypovolemia. New pulse oximeters should be developed combining the AC/DC signals with a functional hemodynamic monitoring of fluid responsiveness to define which patient needs fluid administration., (© 2024 Institute of Physics and Engineering in Medicine.)

To address several common problems of finger vein recognition, a lightweight finger vein recognition algorithm by means of a small sample has been proposed in this study. First of all, a Gabor filter is applied to deal with the images for the purpose of that these processed images can simulate a kind of situation of finger vein at low temperature, such that the generalization ability of the algorithm model can be improved as well. By cutting down the amount of convolutional layers and fully connected layers in VGG-19, a lightweight network can be given. Meanwhile, the activation function of some convolutional layers is replaced to protect the network weight that can be updated successfully. After then, a multi-attention mechanism is introduced to the modified network architecture to result in improving the ability of extracting important features. Finally, a strategy based on transfer learning has been used to reduce the training time in the model training phase. Honestly, it is obvious that the proposed finger vein recognition algorithm has a good performance in recognition accuracy, robustness and speed. The experimental results show that the recognition accuracy can arrive at about 98.45%, which has had better performance in comparison with some existing algorithms., (© 2024. The Author(s).)

Pulse oximeters are widely used in hospitals and homes for measurement of blood oxygen saturation level (SpO 2 ) and heart rate (HR). Concern has been raised regarding a possible bias in obtaining pulse oximeter measurements from different fingertips and the potential effect of skin pigmentation (white, brown, and dark). In this study, we obtained 600 SpO 2 measurements from 20 volunteers using three UK NHS-approved commercial pulse oximeters alongside our custom-developed sensor, and used the Munsell colour system (5YR and 7.5YR cards) to classify the participants' skin pigmentation into three distinct categories (white, brown, and dark). The statistical analysis using ANOVA post hoc tests (Bonferroni correction), a Bland-Altman plot, and a correlation test were then carried out to determine if there was clinical significance in measuring the SpO 2 from different fingertips and to highlight if skin pigmentation affects the accuracy of SpO 2 measurement. The results indicate that although the three commercial pulse oximeters had different means and standard deviations, these differences had no clinical significance.

Objectives: Measurement of digital perfusion, sometimes coupled with a cold challenge, has been widely used as an objective outcome in trials evaluating drug therapies in RP, in addition to patient-reported outcomes or to establish the proof-of-concept in preliminary studies. However, whether digital perfusion is a valid surrogate for clinical outcomes in RP trials has never been explored. The principal aim of this study was to evaluate the potential surrogacy of digital perfusion, by combining individual-level and trial-level data., Methods: We used individual data from a series of n-of-1 trials, and trial data from a network meta-analysis. We estimated individual-level surrogacy through coefficients of determination between digital perfusion and clinical outcomes (R2ind). We further calculated the coefficients of determination between treatment effect on the clinical outcomes and on digital perfusion, at the individual level (R2TEind) and at the trial level (R2trial), using non-weighted linear regression, with their 95% CI calculated through bootstrapping., Results: Results from 33 patients and 24 trials were included in the final analysis. At the individual level, there was no correlation between digital perfusion and clinical outcomes at rest and in response to various cooling tests (the highest R2ind was 0.03 [-0.07, 0.09]), and R2TEind was also very low 0.07 (0, 0.29). At the trial level, the highest value of R2trial was 0.1 (0, 0.477)., Conclusions: Digital perfusion, at rest or in response to a cold challenge, and whatever the method used, does not fulfil the criteria of a valid surrogate for existing patient-reported outcomes in RP trials., (© The Author(s) 2023. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Digital artery flap (DAF) with nail bed graft is a simple method to preserve finger length for fingertip amputations. This study compared the clinical and aesthetic outcomes between replantation and DAF., Methods: Patients who underwent replantation or DAF for a single fingertip amputation (Ishikawa subzone II or III) at the authors' hospital from 2013 to 2021 were retrospectively evaluated. The aesthetic and functional outcomes were finger length and nail deformity at the final follow-up, total active motion, grip strength, Semmes-Weinstein monofilament test, Fingertip Injuries Outcome Score, and Hand20 score., Results: Overall, in 74 analyzed cases (40 replantation, 34 DAF), the median operative time and the median length of hospital stay were longer with replantation than with DAF (188 versus 126 minutes; P < 0.01; 15 versus 4 days; P < 0.01). The success rates of replantation and DAF were 82.5% and 94.1%, respectively. The rate of finger shortening with replantation was significantly lower than with DAF (42.5% versus 82.4%; P < 0.01). There were fewer nail deformities with replantation than with DAF (45.0% versus 67.6%; P = 0.06). The proportion of patients who achieved excellent or good Fingertip Injuries Outcome Score and median Hand20 score were not significantly different between the groups (89.5% versus 85.3%, P = 0.61; 8.0 versus 13.5, P = 0.42, respectively). Median postoperative Semmes-Weinstein monofilament test values were similar between the groups (3.61 versus 3.61; P = 0.23)., Conclusion: In this retrospective study, compared with replantation, DAF for fingertip amputations achieved equivalent postoperative functional outcomes and shorter intraoperative time and hospital stays, but resulted in inferior cosmetic outcomes., Clinical Question/level of Evidence: Therapeutic, III., (Copyright © 2023 by the American Society of Plastic Surgeons.)

Skin color observation provides a simple and non-invasive method to estimate the health status of patients. Capillary Refill Time (CRT) is widely used as an indicator of pathophysiological conditions, especially in emergency patients. While the measurement of CRT is easy to perform, its evaluation is highly subjective. This study proposes a method to aid quantified CRT measurement using an RGB camera. The procedure consists in applying finger compression to the forearm, and the CRT is calculated based on the skin color change after the pressure release. We estimate compression applied by a finger from its fingernail color change during compression. Our study shows a step towards camera-based quantitative CRT for untrained individuals., Competing Interests: Conflicts of Interest None., (Copyright © 2024. Published by Elsevier Ltd.)

Objective: To develop a cuffless method for estimating blood pressure (BP) from fingertip strain plethysmography (SPG) recordings., Methods: A custom-built micro-electromechanical systems (MEMS) strain sensor is employed to record heartbeat-induced vibrations at the fingertip. An XGboost regressor is then trained to relate SPG recordings to beat-to-beat systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP) values. For this purpose, each SPG segment in this setup is represented by a feature vector consisting of cardiac time interval, amplitude features, statistical properties, and demographic information of the subjects. In addition, a novel concept, coined geometric features, are introduced and incorporated into the feature space to further encode the dynamics in SPG recordings. The performance of the regressor is assessed on 32 healthy subjects through 5-fold cross-validation (5-CV) and leave-subject-out cross validation (LSOCV)., Results: Mean absolute errors (MAEs) of 3.88 mmHg and 5.45 mmHg were achieved for DBP and SBP estimations, respectively, in the 5-CV setting. LSOCV yielded MAEs of 8.16 mmHg for DBP and 16.81 mmHg for SBP. Through feature importance analysis, 3 geometric and 26 integral-related features introduced in this work were identified as primary contributors to BP estimation. The method exhibited robustness against variations in blood pressure level (normal to critical) and body mass index (underweight to obese), with MAE ranges of [1.28, 4.28] mmHg and [2.64, 7.52] mmHg, respectively., Conclusion: The findings suggest high potential for SPG-based BP estimation at the fingertip., Significance: This study presents a fundamental step towards the augmentation of optical sensors that are susceptible to dark skin tones.

With the development of biometric identification technology, finger vein identification has received more and more widespread attention for its security, efficiency, and stability. However, because of the performance of the current standard finger vein image acquisition device and the complex internal organization of the finger, the acquired images are often heavily degraded and have lost their texture characteristics. This makes the topology of the finger veins inconspicuous or even difficult to distinguish, greatly affecting the identification accuracy. Therefore, this paper proposes a finger vein image recovery and enhancement algorithm using atmospheric scattering theory. Firstly, to normalize the local over-bright and over-dark regions of finger vein images within a certain threshold, the Gamma transform method is improved in this paper to correct and measure the gray value of a given image. Then, we reconstruct the image based on atmospheric scattering theory and design a pixel mutation filter to segment the venous and non-venous contact zones. Finally, the degraded finger vein images are recovered and enhanced by global image gray value normalization. Experiments on SDUMLA-HMT and ZJ-UVM datasets show that our proposed method effectively achieves the recovery and enhancement of degraded finger vein images. The image restoration and enhancement algorithm proposed in this paper performs well in finger vein recognition using traditional methods, machine learning, and deep learning. The recognition accuracy of the processed image is improved by more than 10% compared to the original image.

Objective: To develop evidence-based recommendations for the non-pharmacological and pharmacological management of Raynaud's phenomenon (RP) and digital ulcers (DUs) in patients with systemic sclerosis and other immune-mediated connective tissue diseases (CTDs)., Methods: A task force comprising 21 rheumatologists, two surgeons (vascular and plastic), two nurses, and one patient representative was established. Following a systematic literature review performed to inform the recommendations, statements were formulated and discussed during two meetings (one online and one in-person). Levels of evidence, grades of recommendation (GoR), and level of agreement (LoA) were determined., Results: Five overarching principles and 13 recommendations were developed. GoR ranged from A to D. The mean ± standard difference (SD) LoA with the overarching principles and recommendations ranged from 7.8±2.1 to 9.8±0.4. Briefly, the management of RP and DUs in patients with CTDs should be coordinated by a multidisciplinary team and based on shared decisions with patients. Nifedipine should be used as first-line therapy for RP and/or DUs. Sildenafil, tadalafil, and/or iloprost IV are second-line options for severe and/or refractory patients with RP and/or DUs. Sildenafil, tadalafil and/or Iloprost IV, should be prescribed for healing and prevention (also including bosentan) of DUs. In patients with RP and/or DUs, non-pharmacological interventions might be considered as add-ons, but there is limited quality and quantity of scientific evidence supporting their use., Conclusions: These recommendations will inform rheumatologists, specialist nurses, other healthcare professionals, and patients about a comprehensive and personalized management of RP and DUs. A research agenda was developed to address unmet needs, particularly for non-pharmacologic interventions.

Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Glomus tumors are a rare, benign neoplasm arising from the neuroarterial structure known as the glomus body, which is a specialized arteriovenous shunt involved in temperature regulation. They account for less than 2% of soft tissue tumors and between 1% and 4.5% of tumors in the hand.. Despite their first descriptions appearing almost 100 years ago, late and missed diagnoses are common, leading to significant suffering. The classic diagnostic triad includes spontaneous pain, a sensation of pressure and tenderness, and cold hypersensitivity. Magnetic resonance imaging remains the most useful imaging modality. The abolition of pain after inflating a blood pressure cuff above the systolic blood pressure level (ischemia test) is highly diagnostic.Therefore, we suggest the routine use of this simple test in cases of upper limb pain of unclear etiology . Surgical excision is the treatment of choice and is curative., (Copyright © 2024. Publicado por Elsevier España, S.L.U.)