Accurate fingertip detection is critical for translating hand gestures into actionable commands in vision-based human‒computer interaction(HCI)systems.However,challenges such as complex backgrounds,dynamic hand postur...Accurate fingertip detection is critical for translating hand gestures into actionable commands in vision-based human‒computer interaction(HCI)systems.However,challenges such as complex backgrounds,dynamic hand postures,and real-time processing constraints hinder reliable detection.This paper introduces a robust framework integrating three key innovations:(1)an adaptive Gaussian mixture model(GMM)enhanced with neighborhood pixel connectivity for precise motion extraction;(2)a weighted YCbCr color-space shadow removal algorithm to eliminate false positives;and(3)a centroid distance method refined with circularity constraints for accurate fingertip localization.Extensive experiments demonstrate a recognition accuracy of 97.26%across diverse scenarios,including varying illuminations,occlusions,and hand rotations.The algorithm processes each frame in 23.43 ms on average,satisfying real-time requirements.Comparative evaluations against state-of-the-art methods reveal significant improvements in precision(8.3%),recall(6.1%),and F-measure(7.8%).This work advances HCI applications such as virtual keyboards,gesture-controlled interfaces,and augmented reality systems.展开更多
Background: The hand is an essential component for performing our daily tasks;as a result, injuries to the fingertip are frequently seen. Accurate evaluation and treatment of fingertip injuries are essential to avoidi...Background: The hand is an essential component for performing our daily tasks;as a result, injuries to the fingertip are frequently seen. Accurate evaluation and treatment of fingertip injuries are essential to avoiding long-term disability, job loss and psychological issues. No matter the injury classification system, maintaining finger length, regaining sensation, and improving appearance are the three main objectives of treatment. The objective of this research was to outline the epidemiology of fingertip injuries treated between 2021 and 2022 at a highly specialized referral hospital in Mexico City. Methodology: This investigation is cross-sectional, retrospective, and observational. From January 2021 to December 2022, 60 patients with a diagnosis of fingertip injury from the South Central Hospital “Pemex” were included. The descriptive statistical analysis was performed using SPSS29. Results: 60 patients were included, 27 (45%) were women and 33 (55%) were men. Allen’s classification was able to classify only 19 patients, of which 18 (94.7%) had a type 1 classification and one (5.26%) had a type 2 classification. 10% of patients experienced complications, which included 2 patients with surgical site infections (3.3%), 3 patients with persistent pain (5%), and 1 patient (1.6%) with graft rejection. Conclusions: There are currently insufficient epidemiological data on hand and wrist injuries and its effects on labor in Mexico. Fingertip injuries require particular care in order to prevent complications and long-term damage. The creation of national registries could help with the creation of reference manuals for the care of hand and wrist injuries in our nation.展开更多
BACKGROUND Injuries to multiple fingertips pose a significant treatment dilemma.Numerous reconstructive options exist,all with the ultimate goal of restoring function and sensibility to the injured fingertips.CASE SUM...BACKGROUND Injuries to multiple fingertips pose a significant treatment dilemma.Numerous reconstructive options exist,all with the ultimate goal of restoring function and sensibility to the injured fingertips.CASE SUMMARY A 24-year-old male suffered injury to multiple fingertips of the right hand,resulting in exposed distal phalanges of the middle,ring,and small fingers.The amputated distal stumps were not possible for replantation.Free flap coverage was selected in order to achieve better functional outcome.The fingertip defects were covered by performing a right second toe split tibial flap using local anesthesia at the harvest site and brachial plexus nerve block for the right upper extremity.At 6-month follow-up,all three of the reconstructed fingertips had some preserved nail growth,Semmes-Weinstein Monofilaments testing was equal to the contralateral side and the Static Two-Point Discrimination were comparable to the contralateral side.CONCLUSION This report provides a novel reconstructive option for the management of multiple fingertip injuries and demonstrates the utility of supermicrosurgery in management of these injuries.展开更多
Sensory function is the most significant criterion when evaluating the prognosis of replanted fingers. Current clinical research has focused on surgical techniques and indications for finger replantation; however, few...Sensory function is the most significant criterion when evaluating the prognosis of replanted fingers. Current clinical research has focused on surgical techniques and indications for finger replantation; however, few studies have focused on recovery of finger sensory function af- ter replantation. This study retrospectively assessed data of eight patients who had undergone nine Zone I replantations of the fingertips in the First Affiliated Hospital of Sun Yat-sen University of China from July 2014 to January 2016. Variations in the extent of damage, with the residual vessels or nerves in some fingers being too short or even missing, prevented tension-free suture repair in some patients. Thus, re- pair of four of the nine fingertips included arteriovenous anastomosis, the remaining five undergoing arterial anastomosis during replanta- tion of the amputated fingers. Three patients underwent nerve repair, whereas the remaining six cases did not. Fingertip replantations were successful in all eight patients. Compared with the patients without vascular anastomosis, no obvious atrophy was visible in the fingertips of patients who did undergo vascular anastomosis during replantation and their sensory function did recover. Fingertip replantation pro- vides good sensory function and cosmetic outcomes when good artery and vein anastomoses have been created, even when digital nerves have not been repaired.展开更多
This paper presents a vision-based fingertip-writing character recognition system. The overall system is implemented through a CMOS image camera on a FPGA chip. A blue cover is mounted on the top of a finger to simpli...This paper presents a vision-based fingertip-writing character recognition system. The overall system is implemented through a CMOS image camera on a FPGA chip. A blue cover is mounted on the top of a finger to simplify fingertip detection and to enhance recognition accuracy. For each character stroke, 8 sample points (including start and end points) are recorded. 7 tangent angles between consecutive sampled points are also recorded as features. In addition, 3 features angles are extracted: angles of the triangle consisting of the start point, end point and average point of all (8 total) sampled points. According to these key feature angles, a simple template matching K-nearest-neighbor classifier is applied to distinguish each character stroke. Experimental result showed that the system can successfully recognize fingertip-writing character strokes of digits and small lower case letter alphabets with an accuracy of almost 100%. Overall, the proposed finger-tip-writing recognition system provides an easy-to-use and accurate visual character input method.展开更多
With the aid of different types of mechanoreceptors,human is capable of perceiving stimuli from surrounding environments and manipulating various objects dexterously.In this paper,a bio-inspired tactile fingertip is d...With the aid of different types of mechanoreceptors,human is capable of perceiving stimuli from surrounding environments and manipulating various objects dexterously.In this paper,a bio-inspired tactile fingertip is designed mimicking human fingertip in both structures and functionalities.Two pairs of strain gages and(Polyvinylidene Fluoride)PVDF films are perpendicularly arranged to simulate the Fast-Adapting(FA)and Slowly Adapting(SA)type mechanoreceptors in human hands,while silicones,Polymethyl Methacrylate(PMMA),and electronic wires are applied to mimic the skin,bone and nerve fibers.Both static and dynamic forces can be perceived sensitively.A preprocessing electric circuit is further designed to transform the resistor changes into voltages,and then filter and amplify the four-channel signals.In addition to strong robustness due to the embedded structure,the developed fingertip is found sensitive to deformations via a force test experiment.Finally,two robotic experiments explore its recognition ability of contact status and object surface.Excellent performance is found with high accuracy of 99.72%achieved in discriminating six surfaces that are ubiquitous in daily life,which demonstrates the effectiveness of our designed tactile sensor.展开更多
This paper presents finite element models of the fingertip skin which have been created to simulate the contact of textile objects with the skin to gain a better understanding of the perception of textiles through the...This paper presents finite element models of the fingertip skin which have been created to simulate the contact of textile objects with the skin to gain a better understanding of the perception of textiles through the skin, the so-called hand of textiles. Many objective and subjective techniques have already been developed for analysing the hand of textiles;however, none of them provide exact overall information concerning the sensation of textiles through the skin. As the human skin is a complex heterogeneous hyperelastic body composed of many particles, some simplifications had to be made at the early stage of building the models;however, their utilitarian value was maintained. The models relate only to mechanical loading of the skin. They predict a low deformation of the fingertip skin under the pressure of virtual heterogeneous material: acrylic, coarse wool, and steel.展开更多
A new design of robot gripper with electrorheological fluid (ERF) semiactive tips is described. There are two remarkable properties using this fingertip. One is the higher lifting capability at little grasp force, whi...A new design of robot gripper with electrorheological fluid (ERF) semiactive tips is described. There are two remarkable properties using this fingertip. One is the higher lifting capability at little grasp force, which can realize stable grasp. Another is the damping controllable which can be used for controlling contact forces. A viscoelastic plastic model for normal direction of the fingertip is proposed to explore the contact behavior. The electric field strength is induced into the dynamic model of contact transition for simulations. The simulation results and conclusions are given.展开更多
Background: Acute fingertip injuries are common and may lead to functional and aesthetic complications if not treated properly. Different types of trauma result in injuries with variable severity and affect certain ri...Background: Acute fingertip injuries are common and may lead to functional and aesthetic complications if not treated properly. Different types of trauma result in injuries with variable severity and affect certain risk groups. Objectives: To study the high-risk groups affected by fingertip injuries, their etiological factors, clinical features, and wound patterns, and the influence of hand dominance. Study Design: A descriptive study of 103 consecutive patients with 144 acutely injured fingertips. Data Collection/Analysis: We obtained demographic data, occupation, hand dominance, time and cause of trauma, and the presenting symptoms. Further, clinical examination, radiological, and laboratory studies were performed. Wound characteristics were classified according to the pulp, nailbed and bone (PNB) classification. The data were analyzed with the Fisher’s exact test and Chi-square test. Results: A total of 103 patients (88 males, 15 females) presented with 144 injured fingertips. The male to female ratio was 5.8:1, and the mean age was 27.5 years. The age group affected most commonly was 16 - 20 years. There was a strong association between hand dominance and fingertip injuries, as in 65% of the cases, the dominant hand was injured more frequently than the non-dominant (p = 0.01). The sharp and blunt injuries observed involved the left hand more than the right and were often the result of machinery-related trauma (p = 0.04). Approximately 68% of the injuries were related to work, while 26% were attributable to domestic accidents. In 22% of the cases, seasonal workers were the category affected most often, followed by factory workers. Nearly half of the injuries were related to working with machines, while door-trapping was the most frequent cause of injury in children under 5. The index finger was injured most frequently (31.9%), followed by the middle finger (27.9%), while the thumb and little fingers were involved least (11% for each). Pulp injuries were seen in 97% of cases, commonly with lacerations (39.6%, n = 139) while complete pulp loss was seen in 12.6% of cases. 87% of the cases were nail bed injuries, often with nail bed lacerations (28.6%, n = 126), while complete nail bed loss was observed in 9.5% of cases. Tuft fractures were the commonest bone injuries (26%), while complete bone loss was seen in 7.7% of the injured bones (n = 104). Conservative management was carried out on 9% of fingers, while the others required various methods of surgical repair. Nail bed repair was performed in 48.8% of cases (n = 126), while bone fixation was required in 20.2% (n = 104). Conclusions: Fingertip injuries are highly common in practice. In our study, the age, gender, mechanism of trauma and hand dominance had their influence on the pattern of injury. Finally, wound characteristics determine the type of management required.展开更多
Zhao Cong, a young pipa (four-stringedChinese lute) performer with the China CentralTraditional Music Ensemble, was born into a familyof musicians. She developed an extraordinaryinterest in this ancient Chinese instru...Zhao Cong, a young pipa (four-stringedChinese lute) performer with the China CentralTraditional Music Ensemble, was born into a familyof musicians. She developed an extraordinaryinterest in this ancient Chinese instrument in herchildhood. When her parents asked展开更多
Background Interactions with virtual 3D objects in the virtual reality(VR)environment using the gesture of fingers captured in a wearable 2D camera have emerging applications in real-life.Method This paper presents an...Background Interactions with virtual 3D objects in the virtual reality(VR)environment using the gesture of fingers captured in a wearable 2D camera have emerging applications in real-life.Method This paper presents an approach of a two-stage convolutional neural network,one for the detection of hand and another for the fingertips.One purpose of VR environments is to transform a virtual 3D object with affine parameters by using the gesture of thumb and index fingers.Results To evaluate the performance of the proposed system,one existing,and another developed egocentric fingertip databases are employed so that learning involves large variations that are common in real-life.Experimental results show that the proposed fingertip detection system outperforms the existing systems in terms of the precision of detection.Conclusion The interaction performance of the proposed system in the VR environment is higher than that of the existing systems in terms of estimation error and correlation between the ground truth and estimated affine parameters.展开更多
Infectious diseases such as coronavirus disease 2019(COVID-19)continue to pose significant global health challenges.Effective management of reinfection risks depends on sustained levels of binding and neutralizing ant...Infectious diseases such as coronavirus disease 2019(COVID-19)continue to pose significant global health challenges.Effective management of reinfection risks depends on sustained levels of binding and neutralizing antibodies.However,conventional methods—such as enzyme-linked immunosorbent assays(ELISA)and virus neutralization tests(VNT)—are limited by complex workflows,long assay durations,and high sample volume requirements,making them less suit-able for routine,decentralized,or time-sensitive surveillance.This study presents a custom-developed tip optofluidic immunoassay(TOI)platform that enables rapid,multiplexed antibody profiling using only 1 mL offingertip blood.The system integrates batch-fabricated microfluidic immunoreactors with a portable chemiluminescent imaging station,completing both binding and neutralization capability assessments within 40 min.TOI achieves a broad dynamic range(3–4 orders of magnitude),high signal-to-noise ratio(10,000),and excellent sensitivity for immunoglobulin G(IgG)detection.A renovated version of the rapid in vitro inhibition assay(RIVIA)is incorporated to evaluate neutralizing an-tibodies against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)with greater speed and cost-effi-ciency.In clinical studies,TOI successfully quantified antibody protection against multiple variants,identifying individ-uals with broad-spectrum immunity to both wild-type and XBB strains.With its high-precision,rapid turnaround,and minimal sample requirement,TOI offers a valuable tool for decentralized immune surveillance and personalized immu-nization strategy development.展开更多
Background Fingertip defect significantly affects the appearance of the hand. The aim of this research was to evaluate the clinical effect of aesthetic fingertip reconstruction with partial second toe transfer.Methods...Background Fingertip defect significantly affects the appearance of the hand. The aim of this research was to evaluate the clinical effect of aesthetic fingertip reconstruction with partial second toe transfer.Methods Between July 2005 and December 2008, 17 patients underwent aesthetic fingertip reconstruction with partial second toe transfer. The mean size of fingertip defects was 0.7 cm （ranging from 0.5-1.1 cm）. Anastomosis was performed between one dominant plantar digital artery and one proper digital artery, between two dorsal digital veins of the toe and two dorsal digital veins of the finger, respectively, for the reconstruction of blood supply to the reconstructed finger. Two plantar digital nerves of the toe were then sutured to two proper digital nerves of the finger for the restoration of fingertip sensation.Results All reconstructed fingers survived completely. The follow-up period ranged from 6 to 24 months, and the appearance of the reconstructed fingertip was similar to that of the normal fingertip. Two-point discrimination of the reconstructed fingertip was （7.8±1.3） mm. The recovered pinch strength of the reconstructed finger was about （89.0±5.1）% of that of the normal finger. Donor site healed well without complications.Conclusions Partial second toe transfer is an ideal aesthetic reconstruction method for fingertip defects; it can not only achieve a satisfactory appearance of the fingertip, but can also obtain excellent sensory and motor functions.展开更多
Purpose:The reconstruction of Allen''s type IV fingertip amputation is a clinical challenge.Our team designed bilateral unequal-sized hallux osteo-onychocutaneous free flaps for the long-term reconstruction of...Purpose:The reconstruction of Allen''s type IV fingertip amputation is a clinical challenge.Our team designed bilateral unequal-sized hallux osteo-onychocutaneous free flaps for the long-term reconstruction of Allen''s type IV fingertip amputation and conducted a retrospective study with a 5-year follow-up aims to evaluate the effects of this technique.Methods:A retrospective analysis with a 5-year follow-up including 13 patients with Allen''s type IV fingertip amputation who were admitted to our hospital from January 2010 to January 2017 was conducted.The patients were treated with bilateral unequal-sized hallux osteo-onychocutaneous free flaps.The operation time,intraoperative blood loss,and complications were recorded,and the survival rate of the transplanted flaps was calculated.During the 5-year follow-up after operation,the nail growth time was recorded and the finger appearance was observed.At the last follow-up appointment,the length,width,and girth of the reconstructed fingertip and contralateral normal fingertip,range of motion of the reconstructed fingertip and contralateral normal fingertip,Semmes-Weinstein test(for the evaluation of tactile sensation),and two-point discrimination testing results were recorded.SPSS 22.0 software was used for the statistical analysis and the data are presented as mean±SD.Results:The mean operation time was(5.62±0.51)h,the mean intraoperative blood loss was(34.15±3.13)mL,and the survival rate of the transplanted flaps was 100%.During the 5-year follow-up,the average nail growth time was(10.14±1.98)months and the average bone union time was(3.78±0.91)months.The length,width,and girth of the reconstructed fingertip were(31.52±3.73)mm,(17.82±1.74)mm,and(59.75±3.04)mm,respectively,which did not differ from those of the contralateral normal fingertip.The range of motion of the reconstructed fingertip was(12.15±2.79)degrees which is different from that of the contralateral normal fingertip.The average tactile sensation evaluated via the Semmes-Weinstein test and the average two-point discrimination test of the reconstructed fingertip were(0.39±0.17)g and(7.46±1.14)mm,respectively,which were not different from those of the contralateral normal fingertip.The average Maryland score of feet in the donor area was 87.66±7.39,which was satisfactory.Conclusion:Bilateral unequal-sized hallux osteo-onychocutaneous free flaps are an effective method to reconstruct Allen''s type IV fingertip amputations with a satisfactory appearance and good sensory function.展开更多
基金funded by the Jiaying University Research Start-Up Fund(grant number 323E0431).
文摘Accurate fingertip detection is critical for translating hand gestures into actionable commands in vision-based human‒computer interaction(HCI)systems.However,challenges such as complex backgrounds,dynamic hand postures,and real-time processing constraints hinder reliable detection.This paper introduces a robust framework integrating three key innovations:(1)an adaptive Gaussian mixture model(GMM)enhanced with neighborhood pixel connectivity for precise motion extraction;(2)a weighted YCbCr color-space shadow removal algorithm to eliminate false positives;and(3)a centroid distance method refined with circularity constraints for accurate fingertip localization.Extensive experiments demonstrate a recognition accuracy of 97.26%across diverse scenarios,including varying illuminations,occlusions,and hand rotations.The algorithm processes each frame in 23.43 ms on average,satisfying real-time requirements.Comparative evaluations against state-of-the-art methods reveal significant improvements in precision(8.3%),recall(6.1%),and F-measure(7.8%).This work advances HCI applications such as virtual keyboards,gesture-controlled interfaces,and augmented reality systems.
文摘Background: The hand is an essential component for performing our daily tasks;as a result, injuries to the fingertip are frequently seen. Accurate evaluation and treatment of fingertip injuries are essential to avoiding long-term disability, job loss and psychological issues. No matter the injury classification system, maintaining finger length, regaining sensation, and improving appearance are the three main objectives of treatment. The objective of this research was to outline the epidemiology of fingertip injuries treated between 2021 and 2022 at a highly specialized referral hospital in Mexico City. Methodology: This investigation is cross-sectional, retrospective, and observational. From January 2021 to December 2022, 60 patients with a diagnosis of fingertip injury from the South Central Hospital “Pemex” were included. The descriptive statistical analysis was performed using SPSS29. Results: 60 patients were included, 27 (45%) were women and 33 (55%) were men. Allen’s classification was able to classify only 19 patients, of which 18 (94.7%) had a type 1 classification and one (5.26%) had a type 2 classification. 10% of patients experienced complications, which included 2 patients with surgical site infections (3.3%), 3 patients with persistent pain (5%), and 1 patient (1.6%) with graft rejection. Conclusions: There are currently insufficient epidemiological data on hand and wrist injuries and its effects on labor in Mexico. Fingertip injuries require particular care in order to prevent complications and long-term damage. The creation of national registries could help with the creation of reference manuals for the care of hand and wrist injuries in our nation.
文摘BACKGROUND Injuries to multiple fingertips pose a significant treatment dilemma.Numerous reconstructive options exist,all with the ultimate goal of restoring function and sensibility to the injured fingertips.CASE SUMMARY A 24-year-old male suffered injury to multiple fingertips of the right hand,resulting in exposed distal phalanges of the middle,ring,and small fingers.The amputated distal stumps were not possible for replantation.Free flap coverage was selected in order to achieve better functional outcome.The fingertip defects were covered by performing a right second toe split tibial flap using local anesthesia at the harvest site and brachial plexus nerve block for the right upper extremity.At 6-month follow-up,all three of the reconstructed fingertips had some preserved nail growth,Semmes-Weinstein Monofilaments testing was equal to the contralateral side and the Static Two-Point Discrimination were comparable to the contralateral side.CONCLUSION This report provides a novel reconstructive option for the management of multiple fingertip injuries and demonstrates the utility of supermicrosurgery in management of these injuries.
基金supported by a grant from the Department of Health of Guangdong Province of China,No.A2016018the Specialized Research Fund for the Doctoral Program of Higher Education,No.20120171120075+3 种基金a grant from the Science and Technology Project of Guangdong Province of China,No.2014A020212479a grant from the Science and Technology Project of Guangdong Province of China,No.2016A010103012a grant from the Science and Technology Program of Guangzhou City of China,No.201300000174a grant from the Doctoral Start-up Project of the Natural Science Foundation of Guangdong Province of China,No.2017A030310302
文摘Sensory function is the most significant criterion when evaluating the prognosis of replanted fingers. Current clinical research has focused on surgical techniques and indications for finger replantation; however, few studies have focused on recovery of finger sensory function af- ter replantation. This study retrospectively assessed data of eight patients who had undergone nine Zone I replantations of the fingertips in the First Affiliated Hospital of Sun Yat-sen University of China from July 2014 to January 2016. Variations in the extent of damage, with the residual vessels or nerves in some fingers being too short or even missing, prevented tension-free suture repair in some patients. Thus, re- pair of four of the nine fingertips included arteriovenous anastomosis, the remaining five undergoing arterial anastomosis during replanta- tion of the amputated fingers. Three patients underwent nerve repair, whereas the remaining six cases did not. Fingertip replantations were successful in all eight patients. Compared with the patients without vascular anastomosis, no obvious atrophy was visible in the fingertips of patients who did undergo vascular anastomosis during replantation and their sensory function did recover. Fingertip replantation pro- vides good sensory function and cosmetic outcomes when good artery and vein anastomoses have been created, even when digital nerves have not been repaired.
文摘This paper presents a vision-based fingertip-writing character recognition system. The overall system is implemented through a CMOS image camera on a FPGA chip. A blue cover is mounted on the top of a finger to simplify fingertip detection and to enhance recognition accuracy. For each character stroke, 8 sample points (including start and end points) are recorded. 7 tangent angles between consecutive sampled points are also recorded as features. In addition, 3 features angles are extracted: angles of the triangle consisting of the start point, end point and average point of all (8 total) sampled points. According to these key feature angles, a simple template matching K-nearest-neighbor classifier is applied to distinguish each character stroke. Experimental result showed that the system can successfully recognize fingertip-writing character strokes of digits and small lower case letter alphabets with an accuracy of almost 100%. Overall, the proposed finger-tip-writing recognition system provides an easy-to-use and accurate visual character input method.
基金funded by National Natural Science Foundation of China under Grant No.52205009Natural Science Foundation of Jiangsu Province under Grant No.BK20210233Open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems.
文摘With the aid of different types of mechanoreceptors,human is capable of perceiving stimuli from surrounding environments and manipulating various objects dexterously.In this paper,a bio-inspired tactile fingertip is designed mimicking human fingertip in both structures and functionalities.Two pairs of strain gages and(Polyvinylidene Fluoride)PVDF films are perpendicularly arranged to simulate the Fast-Adapting(FA)and Slowly Adapting(SA)type mechanoreceptors in human hands,while silicones,Polymethyl Methacrylate(PMMA),and electronic wires are applied to mimic the skin,bone and nerve fibers.Both static and dynamic forces can be perceived sensitively.A preprocessing electric circuit is further designed to transform the resistor changes into voltages,and then filter and amplify the four-channel signals.In addition to strong robustness due to the embedded structure,the developed fingertip is found sensitive to deformations via a force test experiment.Finally,two robotic experiments explore its recognition ability of contact status and object surface.Excellent performance is found with high accuracy of 99.72%achieved in discriminating six surfaces that are ubiquitous in daily life,which demonstrates the effectiveness of our designed tactile sensor.
文摘This paper presents finite element models of the fingertip skin which have been created to simulate the contact of textile objects with the skin to gain a better understanding of the perception of textiles through the skin, the so-called hand of textiles. Many objective and subjective techniques have already been developed for analysing the hand of textiles;however, none of them provide exact overall information concerning the sensation of textiles through the skin. As the human skin is a complex heterogeneous hyperelastic body composed of many particles, some simplifications had to be made at the early stage of building the models;however, their utilitarian value was maintained. The models relate only to mechanical loading of the skin. They predict a low deformation of the fingertip skin under the pressure of virtual heterogeneous material: acrylic, coarse wool, and steel.
文摘A new design of robot gripper with electrorheological fluid (ERF) semiactive tips is described. There are two remarkable properties using this fingertip. One is the higher lifting capability at little grasp force, which can realize stable grasp. Another is the damping controllable which can be used for controlling contact forces. A viscoelastic plastic model for normal direction of the fingertip is proposed to explore the contact behavior. The electric field strength is induced into the dynamic model of contact transition for simulations. The simulation results and conclusions are given.
文摘Background: Acute fingertip injuries are common and may lead to functional and aesthetic complications if not treated properly. Different types of trauma result in injuries with variable severity and affect certain risk groups. Objectives: To study the high-risk groups affected by fingertip injuries, their etiological factors, clinical features, and wound patterns, and the influence of hand dominance. Study Design: A descriptive study of 103 consecutive patients with 144 acutely injured fingertips. Data Collection/Analysis: We obtained demographic data, occupation, hand dominance, time and cause of trauma, and the presenting symptoms. Further, clinical examination, radiological, and laboratory studies were performed. Wound characteristics were classified according to the pulp, nailbed and bone (PNB) classification. The data were analyzed with the Fisher’s exact test and Chi-square test. Results: A total of 103 patients (88 males, 15 females) presented with 144 injured fingertips. The male to female ratio was 5.8:1, and the mean age was 27.5 years. The age group affected most commonly was 16 - 20 years. There was a strong association between hand dominance and fingertip injuries, as in 65% of the cases, the dominant hand was injured more frequently than the non-dominant (p = 0.01). The sharp and blunt injuries observed involved the left hand more than the right and were often the result of machinery-related trauma (p = 0.04). Approximately 68% of the injuries were related to work, while 26% were attributable to domestic accidents. In 22% of the cases, seasonal workers were the category affected most often, followed by factory workers. Nearly half of the injuries were related to working with machines, while door-trapping was the most frequent cause of injury in children under 5. The index finger was injured most frequently (31.9%), followed by the middle finger (27.9%), while the thumb and little fingers were involved least (11% for each). Pulp injuries were seen in 97% of cases, commonly with lacerations (39.6%, n = 139) while complete pulp loss was seen in 12.6% of cases. 87% of the cases were nail bed injuries, often with nail bed lacerations (28.6%, n = 126), while complete nail bed loss was observed in 9.5% of cases. Tuft fractures were the commonest bone injuries (26%), while complete bone loss was seen in 7.7% of the injured bones (n = 104). Conservative management was carried out on 9% of fingers, while the others required various methods of surgical repair. Nail bed repair was performed in 48.8% of cases (n = 126), while bone fixation was required in 20.2% (n = 104). Conclusions: Fingertip injuries are highly common in practice. In our study, the age, gender, mechanism of trauma and hand dominance had their influence on the pattern of injury. Finally, wound characteristics determine the type of management required.
文摘Zhao Cong, a young pipa (four-stringedChinese lute) performer with the China CentralTraditional Music Ensemble, was born into a familyof musicians. She developed an extraordinaryinterest in this ancient Chinese instrument in herchildhood. When her parents asked
文摘Background Interactions with virtual 3D objects in the virtual reality(VR)environment using the gesture of fingers captured in a wearable 2D camera have emerging applications in real-life.Method This paper presents an approach of a two-stage convolutional neural network,one for the detection of hand and another for the fingertips.One purpose of VR environments is to transform a virtual 3D object with affine parameters by using the gesture of thumb and index fingers.Results To evaluate the performance of the proposed system,one existing,and another developed egocentric fingertip databases are employed so that learning involves large variations that are common in real-life.Experimental results show that the proposed fingertip detection system outperforms the existing systems in terms of the precision of detection.Conclusion The interaction performance of the proposed system in the VR environment is higher than that of the existing systems in terms of estimation error and correlation between the ground truth and estimated affine parameters.
基金supported by the Outstanding Young Innovator Fund,Shenzhen Institute of Advanced Technology,Chinese Academy of Sciences(to X.T.)the State Key Laboratory of Biomedical Imaging Science and System+5 种基金Shenzhen Basic Research Project of Natural Science Foundation(JCYJ20230808105701004 to Y.C.)Shenzhen Science and Technology Innovations Committee(JSGGZD20220822095200001 to H.Y.)National Science Foundation of China(32270937 to F.Y.)Ministry of Science and Technology of China(2021D0102 to Y.C.)Guangdong Basic and Applied Basic Research Foundation(2025A1515012136 to H.L.)Medicine Plus Program of Shenzhen University(2024YG015 to Y.C.).
文摘Infectious diseases such as coronavirus disease 2019(COVID-19)continue to pose significant global health challenges.Effective management of reinfection risks depends on sustained levels of binding and neutralizing antibodies.However,conventional methods—such as enzyme-linked immunosorbent assays(ELISA)and virus neutralization tests(VNT)—are limited by complex workflows,long assay durations,and high sample volume requirements,making them less suit-able for routine,decentralized,or time-sensitive surveillance.This study presents a custom-developed tip optofluidic immunoassay(TOI)platform that enables rapid,multiplexed antibody profiling using only 1 mL offingertip blood.The system integrates batch-fabricated microfluidic immunoreactors with a portable chemiluminescent imaging station,completing both binding and neutralization capability assessments within 40 min.TOI achieves a broad dynamic range(3–4 orders of magnitude),high signal-to-noise ratio(10,000),and excellent sensitivity for immunoglobulin G(IgG)detection.A renovated version of the rapid in vitro inhibition assay(RIVIA)is incorporated to evaluate neutralizing an-tibodies against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)with greater speed and cost-effi-ciency.In clinical studies,TOI successfully quantified antibody protection against multiple variants,identifying individ-uals with broad-spectrum immunity to both wild-type and XBB strains.With its high-precision,rapid turnaround,and minimal sample requirement,TOI offers a valuable tool for decentralized immune surveillance and personalized immu-nization strategy development.
基金This work was supported by a grant from the Natural Science Foundation of Guangdong Province （No. 8151031701000001）.
文摘Background Fingertip defect significantly affects the appearance of the hand. The aim of this research was to evaluate the clinical effect of aesthetic fingertip reconstruction with partial second toe transfer.Methods Between July 2005 and December 2008, 17 patients underwent aesthetic fingertip reconstruction with partial second toe transfer. The mean size of fingertip defects was 0.7 cm （ranging from 0.5-1.1 cm）. Anastomosis was performed between one dominant plantar digital artery and one proper digital artery, between two dorsal digital veins of the toe and two dorsal digital veins of the finger, respectively, for the reconstruction of blood supply to the reconstructed finger. Two plantar digital nerves of the toe were then sutured to two proper digital nerves of the finger for the restoration of fingertip sensation.Results All reconstructed fingers survived completely. The follow-up period ranged from 6 to 24 months, and the appearance of the reconstructed fingertip was similar to that of the normal fingertip. Two-point discrimination of the reconstructed fingertip was （7.8±1.3） mm. The recovered pinch strength of the reconstructed finger was about （89.0±5.1）% of that of the normal finger. Donor site healed well without complications.Conclusions Partial second toe transfer is an ideal aesthetic reconstruction method for fingertip defects; it can not only achieve a satisfactory appearance of the fingertip, but can also obtain excellent sensory and motor functions.
基金supported by Qingdao Excellent Young Medical Talents ProjectThe Youth Talent Support Project of Shandong Medical Association.
文摘Purpose:The reconstruction of Allen''s type IV fingertip amputation is a clinical challenge.Our team designed bilateral unequal-sized hallux osteo-onychocutaneous free flaps for the long-term reconstruction of Allen''s type IV fingertip amputation and conducted a retrospective study with a 5-year follow-up aims to evaluate the effects of this technique.Methods:A retrospective analysis with a 5-year follow-up including 13 patients with Allen''s type IV fingertip amputation who were admitted to our hospital from January 2010 to January 2017 was conducted.The patients were treated with bilateral unequal-sized hallux osteo-onychocutaneous free flaps.The operation time,intraoperative blood loss,and complications were recorded,and the survival rate of the transplanted flaps was calculated.During the 5-year follow-up after operation,the nail growth time was recorded and the finger appearance was observed.At the last follow-up appointment,the length,width,and girth of the reconstructed fingertip and contralateral normal fingertip,range of motion of the reconstructed fingertip and contralateral normal fingertip,Semmes-Weinstein test(for the evaluation of tactile sensation),and two-point discrimination testing results were recorded.SPSS 22.0 software was used for the statistical analysis and the data are presented as mean±SD.Results:The mean operation time was(5.62±0.51)h,the mean intraoperative blood loss was(34.15±3.13)mL,and the survival rate of the transplanted flaps was 100%.During the 5-year follow-up,the average nail growth time was(10.14±1.98)months and the average bone union time was(3.78±0.91)months.The length,width,and girth of the reconstructed fingertip were(31.52±3.73)mm,(17.82±1.74)mm,and(59.75±3.04)mm,respectively,which did not differ from those of the contralateral normal fingertip.The range of motion of the reconstructed fingertip was(12.15±2.79)degrees which is different from that of the contralateral normal fingertip.The average tactile sensation evaluated via the Semmes-Weinstein test and the average two-point discrimination test of the reconstructed fingertip were(0.39±0.17)g and(7.46±1.14)mm,respectively,which were not different from those of the contralateral normal fingertip.The average Maryland score of feet in the donor area was 87.66±7.39,which was satisfactory.Conclusion:Bilateral unequal-sized hallux osteo-onychocutaneous free flaps are an effective method to reconstruct Allen''s type IV fingertip amputations with a satisfactory appearance and good sensory function.
