The stiffness information of the grasped object at the initial contact stage can be effectively used to adjust the grasping force of the prosthetic hand,thereby preventing damage to the object.However,the object’s de...The stiffness information of the grasped object at the initial contact stage can be effectively used to adjust the grasping force of the prosthetic hand,thereby preventing damage to the object.However,the object’s deformation and contact force are often minimal during the initial stage and not easily obtained directly.Additionally,stiffness estimation methods for prosthetic hands often require contact sensors,which can easily lead to poor contact issues.To address the above issues,this paper proposes the model-based stiffness estimation of grasped objects for underactuated prosthetic hands without force sensors.First,the kinematic model is linearized at the contact points to achieve the estimation of the linkage angles in the underactuated prosthetic hand.Secondly,the motor parameters are estimated using the Kalman filter method,and the grasping force is obtained from the dynamic model of the underactuated prosthetic hand.Finally,the contact model of the prosthetic hand grasping an object is established,and an online stiffness estimation method based on the contact model for the grasped object is proposed using the iterative reweighted least squares method.Experimental results show that this method can estimate the stiffness of grasped objects within 250 ms without contact sensors.展开更多
The prosthesis is an artificial device that can replace an organ of a human body member to restore a compromised function. It is necessary following the removal of a human organ, which can occur as a result of an illn...The prosthesis is an artificial device that can replace an organ of a human body member to restore a compromised function. It is necessary following the removal of a human organ, which can occur as a result of an illness, trauma or congenital malformation. The trans-tibia prosthesis, in particular, allows the amputee patient to recover the impaired function and regain autonomy, while facilitating their daily social integration. The trans-tibia prosthesis consists of a socket, a sleeve, connecting elements and a prosthetic foot. Each of these components plays a very important role. Among these components, the prosthetic foot usually called “SACH foot” is very often replaced due to cracking and therefore has a fairly short lifespan. At the Center for Equipment and Rehabilitation of Kabalaye (CERK), the SACH foot made using polyurethane and wood is imported and is given to patients with reduced mobility. The aim of this article is twofold, on the one hand, to make a social and pathological study of trans-tibia amputees in relation to the use of the SACH foot prosthesis, on the other hand, to compare this foot with a new prosthetic foot proposed and which is manufactured using extruded polystyrene. The result of prosthetic tests carried out on twenty-four amputees showed that the foot manufactured using extruded polystyrene is better in terms of resistance, bulk and adaptability to active amputees.展开更多
Functionally Graded Materials(FGMs)are innovative advanced quality materials in the field of composites concerning their strength,mechanical,and thermal properties.Nowadays,the modern requirement of the industry in th...Functionally Graded Materials(FGMs)are innovative advanced quality materials in the field of composites concerning their strength,mechanical,and thermal properties.Nowadays,the modern requirement of the industry in the fields of health care,aerospace,and power sectors needs the rapid evolution of new components,which allows researchers to invent new materials to satisfy the functional requirements of modern technology.Tissue engineering is one of the most concerned areas of the application of FGM in the healthcare sector,where the tailored properties of FGM play a significant role in building and growing an artificial structure that heals the damaged tissue of the body parts and meets the desired application that the part needs to perform.This paper highlights the suitability of the combination of a nano⁃structure enhanced epoxy functionally graded material,its properties,and applicability in the design of a prosthetic foot where it provides the mobility and comfort of the body part like natural tissue.The analytical study is done by designing an ANSYS model and simulating the results of equivalent stress and directional deformation.The Finite Element(FE)approach is used to optimize the output results of stress⁃strain analysis,different weight percentages of nano⁃filler are taken for performance enhancement.A comparative analysis is done with the previously established results taking carbon fiber⁃reinforced composites that offer a successful validation of the present results obtained.Furthermore,this study also provides a clear understanding of the justification of the composition considered for the effective application in the field of prosthetics field.展开更多
AIM:To investigate the outcome of combined anterior corneal elastic sublaminectomy,conjunctival flap,and prosthetic eyepiece for ocular atrophy following foldable capsular vitreous body(FCVB)implantation in severe tra...AIM:To investigate the outcome of combined anterior corneal elastic sublaminectomy,conjunctival flap,and prosthetic eyepiece for ocular atrophy following foldable capsular vitreous body(FCVB)implantation in severe trauma.METHODS:This study conducted a retrospective analysis of 38 patients who underwent conjunctival flap coverage followed by prosthetic eyepiece fitting after developing ocular atrophy secondary to FCVB surgery.Anterior corneal elastic sublaminectomy combined with conjunctival coverage was performed on the FCVBimplanted atrophic eyes.Prosthetic lenses were fitted after complete healing of the stroma and conjunctiva and suture removal.Corneal irritation,eyeball protrusion,axial length,lid height,cosmetic satisfaction,and pain numerical rating scale scores were observed before the conjunctival flap covering and after the prosthetic eyepiece surgery.RESULTS:The ocular protrusion was 11 mm preoperatively and 14 mm postoperatively,with the difference being statistically significant(Z=-5.459,P<0.001).The ocular axis length was 20.82±0.94 mm in the experimental group and 23.57±0.33 mm in the control group,showing a statistically significant difference(t=-20.207,P<0.05).The lid height was 6 mm in the experimental group and 9 mm in the control group,a difference that was statistically significant(Z=-5.326,P<0.001).The appearance satisfaction score was 1 in the experimental group and 4 in the control group,with this difference being statistically significant(Z=-5.447,P=0.001).Regarding the pain numerical rating scale score,the ranges were 0-2 in the experimental group and 0 in the control group.No discomfort was reported after wearing the prosthetic eyepiece,and the difference was not statistically significant(Z=-1.100,P>0.05).There was no statistically significant difference between pre-and post-treatment satisfaction.CONCLUSION:A conjunctival flap covering and a prosthetic eyepiece after FCVB postoperative atrophy can reduce the number of surgeries,alleviate patients’economic burdens,satisfy patients’psychological eyeball retention requirements,and provide better cosmetic efficacies for patients desiring eyeball retention or silicone-oil dependence.展开更多
A new prosthetic hand with a fixed thumb and four fingers actuated by Shape Memory Alloy （SMA） type artificial muscle has been developed in this paper. Different from typical geared motor, SMA actuator is lightweigh...A new prosthetic hand with a fixed thumb and four fingers actuated by Shape Memory Alloy （SMA） type artificial muscle has been developed in this paper. Different from typical geared motor, SMA actuator is lightweight and silent, however shows a little short stroke and small attracting force per each unit. In order to achieve enough output force and motion range of each finger, multiple SMA type artificial muscles with special device which facilitates enough length are equipped in the hand. The fundamental properties of the SMA type artificial muscle including output force and electrical response were determined experimentally and considered for the design of hand mechanism. Besides, the structure of each finger and whole system has been designed based on observation of human hand. The electrical hardware to control multiple shape memory alloy type artificial muscles has been also developed. Finally, the usefulness of the prosthetic hand has been investigated through experiments for grasping several types of objects.展开更多
The high frequency of dental extractions creates a high demand for prosthetic rehabilitation. Therefore, this study aimed to describe the profile of consumers of prosthetic care at the Institute of Odontology and Stom...The high frequency of dental extractions creates a high demand for prosthetic rehabilitation. Therefore, this study aimed to describe the profile of consumers of prosthetic care at the Institute of Odontology and Stomatology in Dakar. It was a descriptive and retrospective study of patients who had been consulted at the prosthetic clinic of the Institute of Odontology and Stomatology of Dakar. Data were collected from medical records from 09 November 2019 to 09 June 2020. The tools used to collect and process the information were the Sphinx software and the Excel spreadsheet. Out of the 101 patient records, 51% were male and 48% belonged to the age group of 18 to 39 years. Nearly 38.61% of the patients lived less than 5 km from the health care facility and 70.3% of the respondents had a monthly income of fewer than 100,000 FCFA. Clinically, 96% of patients came for functional reasons, 78.2% for aesthetic reasons, and partial edentulism was the most frequent diagnosis (96%). Chi-square tests were performed to find a dependency or non-dependency relationship between diagnosis and age, but also between income and treatment cost. In sum, age and diagnosis were independent of each other, just as patient income was not related to treatment cost. Proximity to health facilities, income, and cost of treatment are factors that influence accessibility to oral health care. It is important to integrate the profile of the consumer of care into global management.展开更多
Re-screening following methicillin-resistant Staphylococcus aureus(MRSA) decolonization will be helpful to minimize the development of prosthetic joint infection among MRSA colonizers.
To assist an amputee in regaining his or her daily quality of life,based on analysis of the motion characteristics of the human hip,a 2-UPR/URR parallel mechanism with a passive limb was designed.The inverse kinematic...To assist an amputee in regaining his or her daily quality of life,based on analysis of the motion characteristics of the human hip,a 2-UPR/URR parallel mechanism with a passive limb was designed.The inverse kinematics of this mechanism was analyzed based on a closed-loop vector method.The constrained Jacobian matrix and kinematic Jacobian matrix of each limb were then analyzed,and a 6×6 fully Jacobian matrix was constructed.Based on this,kinematic performances were analyzed and summarized.Finally,the dynamic model of the mechanism was constructed based on the virtual work principle,and its theoretical solution was compared with the numerical results,which were obtained in a simulation environment.Results showed that the prosthetic mechanism had a larger rotating workspace and better mechanical performance,which accorded a range of motion and bearing capacity similar to that of the human hip in multiple gait modes.Moreover,the validity of the dynamic model and inverse kinematics were verified by comparing the theoretical and simulation results.Furthermore,with flexion and extension,the torque change in the hip prosthetic mechanism was similar to that of the human hip,which demonstrated the feasibility of the hip prosthetic mechanism and its good dynamic performance.展开更多
A five-fingered,multi-sensory and biomimetic hand is presented.The cambered palm is specially designed by utilizing the knowledge of anatomy.The position of each finger is arranged according to human hand skeleton.Eac...A five-fingered,multi-sensory and biomimetic hand is presented.The cambered palm is specially designed by utilizing the knowledge of anatomy.The position of each finger is arranged according to human hand skeleton.Each finger with three phalanges could fulfill flexion-extension movement independently.All the fingers are designed using coupling link mechanism.The location of the thumb is designed by maximizing interaction area between the thumb and other fingers.The opposite thumb could grasp along a cone surface,while maintaining its function.The hardware architecture is divided into control system and human-machine interaction system.The mechanical parts,sensors and motion control systems are integrated in the hand structure.In addition,a skin-like glove is designed,which makes the hand more humanlike.According to our primary experimental results,the hand can accomplish several grasp modes by applying an intuitive surface electromyography control scheme.The success rate of 10 modes is up to 90%.展开更多
A grasping force control strategy is proposed in order to complete various free manipulations by using anthropomorphic prosthetic hand. The position-based impedance control and force-tracking impedance control are use...A grasping force control strategy is proposed in order to complete various free manipulations by using anthropomorphic prosthetic hand. The position-based impedance control and force-tracking impedance control are used in free and constraint spaces, respectively. The fuzzy observer is adopted in transition in order to switch control mode. Two control modes use one position-based impedance controller. In order to achieve grasping force track, reference force is added to the impedance controller in the constraint space. Trajectory tracking in free space and torque tracking in constrained space are realized, and reliability of mode switch and stability of system are achieved. An adaptive sliding mode friction compensation method is proposed. This method makes use of terminal sliding mode idea to design sliding mode function, which makes the tracking error converge to zero in finite time and avoids the problem of conventional sliding surface that tracking error cannot converge to zero. Based on the characteristic of the exponential form friction, the sliding mode control law including the estimation of friction parameter is obtained through terminal sliding mode idea, and the online parameter update laws are obtained based on Lyapunov stability theorem. The experiments on the HIT Prosthetic Hand IV are carried out to evaluate the grasping force control strategy, and the experiment results verify the effectiveness of this control strategy.展开更多
An underactuated finger structure actuated by tendon-driven system is presented.Kinematics and static analysis of the finger is done,and the results indicate that the prosthetic finger structure is effective and feasi...An underactuated finger structure actuated by tendon-driven system is presented.Kinematics and static analysis of the finger is done,and the results indicate that the prosthetic finger structure is effective and feasible.Based on the design of finger,a prosthetic hand is designed.The hand is composed of 5 independent fingers and it looks more like humanoid.Its size is about 85% of an adult's hand and weights about 350 g.Except the thumb finger,each finger is actuated by one DC motor,gear head and a tendon,and has three curling/extension joints.The thumb finger which is different from other existing prostheses is a novel design scheme.The thumb finger has four joints including three curling/extension joints and a joint which is used to realize the motion of the thumb related to the palm,and these joints are also driven by one DC motor,harmonic drive and a tendon.The underactuation and adaptive curling/extension motion of the finger are realized by joint torsion springs.A high-powered chip of digital signal processing(DSP)is the main part of the electrical system which is used for the motors control,data collection,communication with external controlling source,and so on.To improve the reliability of the hand,structures and sensors are designed and made as simply as possible.The hand has strong manipulation capabilities that have been verified by finger motion and grasping tests and it can satisfy the daily operational needs and psychological needs of deformities.展开更多
Dear editor,Fungal endocarditis is a rare disease with a poor prognosis,suboptimal diagnostic tools responsible for long diagnostic delays in most cases,and poorly defined activity of most antifungal agents in endocar...Dear editor,Fungal endocarditis is a rare disease with a poor prognosis,suboptimal diagnostic tools responsible for long diagnostic delays in most cases,and poorly defined activity of most antifungal agents in endocarditis.^([1])The burden of diagnosis still lies with clinicians:they need a展开更多
Discriminating sterile inflammation from infection, especially in cases of aseptic loosening versus an actual prosthetic joint infection, is challenging and has significant treatment implications. Our goal was to eval...Discriminating sterile inflammation from infection, especially in cases of aseptic loosening versus an actual prosthetic joint infection, is challenging and has significant treatment implications. Our goal was to evaluate a novel human monoclonal antibody（mAb） probe directed against the Gram-positive bacterial surface molecule lipoteichoic acid（LTA）. Specificity and affinity were assessed in vitro. We then radiolabeled the anti-LTA mAb and evaluated its effectiveness as a diagnostic imaging tool for detecting infection via immuno PET imaging in an in vivo mouse model of prosthetic joint infection（PJI）. In vitro and ex vivo binding of the anti-LTA mAb to pathogenic bacteria was measured with Octet, ELISA, and flow cytometry. The in vivo PJI mouse model was assessed using traditional imaging modalities, including positron emission tomography（PET） with [^（18）F]FDG and [^（18）F]Na F as well as X-ray computed tomography（CT）, before being evaluated with the zirconium-89-labeled antibody specific for LTA（[^（89）Zr]SAC55）.The anti-LTA mAb exhibited specific binding in vitro to LTA-expressing bacteria. Results from imaging showed that our model could reliably simulate infection at the surgical site by bioluminescent imaging, conventional PET tracer imaging, and bone morphological changes by CT. One day following injection of both the radiolabeled anti-LTA and isotype control antibodies, the anti-LTA antibody demonstrated significantly greater（P 〈 0.05） uptake at S. aureus-infected prosthesis sites over either the same antibody at sterile prosthesis sites or of control non-specific antibody at infected prosthesis sites. Taken together, the radiolabeled anti-LTA mAb, [^（89）Zr]SAC55, may serve as a valuable diagnostic molecular imaging probe to help distinguish between sterile inflammation and infection in the setting of PJI. Future studies are needed to determine whether these findings will translate to human PJI.展开更多
We present the development of a novel prosthetic hand based on the underactuated mechanism. The aim is focused on increasing its dexterity while keeping the same dimension and weight of a traditional prosthetic device...We present the development of a novel prosthetic hand based on the underactuated mechanism. The aim is focused on increasing its dexterity while keeping the same dimension and weight of a traditional prosthetic device. The hybrid step motor is used as the actuator, which enables the finger to keep enough high contact torque on the grasped object with less energy consumption provided by the holding torque. The grasping force of the finger is estimated from the base joint torque, and the adoption of impedance control has provided compliance in the grasping. Also a parallel observer is used to switch over between the impedance control and the torque holding mode. The experimental results show the effectiveness of the design and control strategy.展开更多
We present the case of a 74 year old woman suffering from severe mitral valve incompetence and rapid atrial fibrillation. After an appropriate vitamin K antagonist(VKA) therapy, the patient underwent mitral valve repl...We present the case of a 74 year old woman suffering from severe mitral valve incompetence and rapid atrial fibrillation. After an appropriate vitamin K antagonist(VKA) therapy, the patient underwent mitral valve replacement by bioprosthesis. Then, the patient was rehospitalized for jaundice. Suspecting hepatotoxicity, VKA was discontinued and fondaparinux was started. During this treatment, the patient developed a symptomatic atrial thrombus. After exclusion of a hepatic disease, VKA was re-established with hemodynamic and liver enzymes normalization and atrial thrombus resolution. Caution has to be used when considering fondaparinux as an alternative strategy to VKA in patients with multiple thrombotic risk factors.展开更多
基金supported by the National Natural Science Foundation of China under Grant 52275297.
文摘The stiffness information of the grasped object at the initial contact stage can be effectively used to adjust the grasping force of the prosthetic hand,thereby preventing damage to the object.However,the object’s deformation and contact force are often minimal during the initial stage and not easily obtained directly.Additionally,stiffness estimation methods for prosthetic hands often require contact sensors,which can easily lead to poor contact issues.To address the above issues,this paper proposes the model-based stiffness estimation of grasped objects for underactuated prosthetic hands without force sensors.First,the kinematic model is linearized at the contact points to achieve the estimation of the linkage angles in the underactuated prosthetic hand.Secondly,the motor parameters are estimated using the Kalman filter method,and the grasping force is obtained from the dynamic model of the underactuated prosthetic hand.Finally,the contact model of the prosthetic hand grasping an object is established,and an online stiffness estimation method based on the contact model for the grasped object is proposed using the iterative reweighted least squares method.Experimental results show that this method can estimate the stiffness of grasped objects within 250 ms without contact sensors.
文摘The prosthesis is an artificial device that can replace an organ of a human body member to restore a compromised function. It is necessary following the removal of a human organ, which can occur as a result of an illness, trauma or congenital malformation. The trans-tibia prosthesis, in particular, allows the amputee patient to recover the impaired function and regain autonomy, while facilitating their daily social integration. The trans-tibia prosthesis consists of a socket, a sleeve, connecting elements and a prosthetic foot. Each of these components plays a very important role. Among these components, the prosthetic foot usually called “SACH foot” is very often replaced due to cracking and therefore has a fairly short lifespan. At the Center for Equipment and Rehabilitation of Kabalaye (CERK), the SACH foot made using polyurethane and wood is imported and is given to patients with reduced mobility. The aim of this article is twofold, on the one hand, to make a social and pathological study of trans-tibia amputees in relation to the use of the SACH foot prosthesis, on the other hand, to compare this foot with a new prosthetic foot proposed and which is manufactured using extruded polystyrene. The result of prosthetic tests carried out on twenty-four amputees showed that the foot manufactured using extruded polystyrene is better in terms of resistance, bulk and adaptability to active amputees.
基金Sponsored by the Science and Technology Department,Government of Ddisha(Grant No.3724/ST,Bhubaneswar,dt.14.09.2022).
文摘Functionally Graded Materials(FGMs)are innovative advanced quality materials in the field of composites concerning their strength,mechanical,and thermal properties.Nowadays,the modern requirement of the industry in the fields of health care,aerospace,and power sectors needs the rapid evolution of new components,which allows researchers to invent new materials to satisfy the functional requirements of modern technology.Tissue engineering is one of the most concerned areas of the application of FGM in the healthcare sector,where the tailored properties of FGM play a significant role in building and growing an artificial structure that heals the damaged tissue of the body parts and meets the desired application that the part needs to perform.This paper highlights the suitability of the combination of a nano⁃structure enhanced epoxy functionally graded material,its properties,and applicability in the design of a prosthetic foot where it provides the mobility and comfort of the body part like natural tissue.The analytical study is done by designing an ANSYS model and simulating the results of equivalent stress and directional deformation.The Finite Element(FE)approach is used to optimize the output results of stress⁃strain analysis,different weight percentages of nano⁃filler are taken for performance enhancement.A comparative analysis is done with the previously established results taking carbon fiber⁃reinforced composites that offer a successful validation of the present results obtained.Furthermore,this study also provides a clear understanding of the justification of the composition considered for the effective application in the field of prosthetics field.
基金Supported by National Natural Science Foundation of China(No.82260210)General Project of Jiangxi Provincial Traditional Chinese Medicine Science and Technology Plan(No.2023B1368).
文摘AIM:To investigate the outcome of combined anterior corneal elastic sublaminectomy,conjunctival flap,and prosthetic eyepiece for ocular atrophy following foldable capsular vitreous body(FCVB)implantation in severe trauma.METHODS:This study conducted a retrospective analysis of 38 patients who underwent conjunctival flap coverage followed by prosthetic eyepiece fitting after developing ocular atrophy secondary to FCVB surgery.Anterior corneal elastic sublaminectomy combined with conjunctival coverage was performed on the FCVBimplanted atrophic eyes.Prosthetic lenses were fitted after complete healing of the stroma and conjunctiva and suture removal.Corneal irritation,eyeball protrusion,axial length,lid height,cosmetic satisfaction,and pain numerical rating scale scores were observed before the conjunctival flap covering and after the prosthetic eyepiece surgery.RESULTS:The ocular protrusion was 11 mm preoperatively and 14 mm postoperatively,with the difference being statistically significant(Z=-5.459,P<0.001).The ocular axis length was 20.82±0.94 mm in the experimental group and 23.57±0.33 mm in the control group,showing a statistically significant difference(t=-20.207,P<0.05).The lid height was 6 mm in the experimental group and 9 mm in the control group,a difference that was statistically significant(Z=-5.326,P<0.001).The appearance satisfaction score was 1 in the experimental group and 4 in the control group,with this difference being statistically significant(Z=-5.447,P=0.001).Regarding the pain numerical rating scale score,the ranges were 0-2 in the experimental group and 0 in the control group.No discomfort was reported after wearing the prosthetic eyepiece,and the difference was not statistically significant(Z=-1.100,P>0.05).There was no statistically significant difference between pre-and post-treatment satisfaction.CONCLUSION:A conjunctival flap covering and a prosthetic eyepiece after FCVB postoperative atrophy can reduce the number of surgeries,alleviate patients’economic burdens,satisfy patients’psychological eyeball retention requirements,and provide better cosmetic efficacies for patients desiring eyeball retention or silicone-oil dependence.
文摘A new prosthetic hand with a fixed thumb and four fingers actuated by Shape Memory Alloy （SMA） type artificial muscle has been developed in this paper. Different from typical geared motor, SMA actuator is lightweight and silent, however shows a little short stroke and small attracting force per each unit. In order to achieve enough output force and motion range of each finger, multiple SMA type artificial muscles with special device which facilitates enough length are equipped in the hand. The fundamental properties of the SMA type artificial muscle including output force and electrical response were determined experimentally and considered for the design of hand mechanism. Besides, the structure of each finger and whole system has been designed based on observation of human hand. The electrical hardware to control multiple shape memory alloy type artificial muscles has been also developed. Finally, the usefulness of the prosthetic hand has been investigated through experiments for grasping several types of objects.
文摘The high frequency of dental extractions creates a high demand for prosthetic rehabilitation. Therefore, this study aimed to describe the profile of consumers of prosthetic care at the Institute of Odontology and Stomatology in Dakar. It was a descriptive and retrospective study of patients who had been consulted at the prosthetic clinic of the Institute of Odontology and Stomatology of Dakar. Data were collected from medical records from 09 November 2019 to 09 June 2020. The tools used to collect and process the information were the Sphinx software and the Excel spreadsheet. Out of the 101 patient records, 51% were male and 48% belonged to the age group of 18 to 39 years. Nearly 38.61% of the patients lived less than 5 km from the health care facility and 70.3% of the respondents had a monthly income of fewer than 100,000 FCFA. Clinically, 96% of patients came for functional reasons, 78.2% for aesthetic reasons, and partial edentulism was the most frequent diagnosis (96%). Chi-square tests were performed to find a dependency or non-dependency relationship between diagnosis and age, but also between income and treatment cost. In sum, age and diagnosis were independent of each other, just as patient income was not related to treatment cost. Proximity to health facilities, income, and cost of treatment are factors that influence accessibility to oral health care. It is important to integrate the profile of the consumer of care into global management.
文摘Re-screening following methicillin-resistant Staphylococcus aureus(MRSA) decolonization will be helpful to minimize the development of prosthetic joint infection among MRSA colonizers.
基金Supported by Beijing Natural Science Foundation(Grant No.L172021)National Natural Science Foundation of China(Grant No.51875033).
文摘To assist an amputee in regaining his or her daily quality of life,based on analysis of the motion characteristics of the human hip,a 2-UPR/URR parallel mechanism with a passive limb was designed.The inverse kinematics of this mechanism was analyzed based on a closed-loop vector method.The constrained Jacobian matrix and kinematic Jacobian matrix of each limb were then analyzed,and a 6×6 fully Jacobian matrix was constructed.Based on this,kinematic performances were analyzed and summarized.Finally,the dynamic model of the mechanism was constructed based on the virtual work principle,and its theoretical solution was compared with the numerical results,which were obtained in a simulation environment.Results showed that the prosthetic mechanism had a larger rotating workspace and better mechanical performance,which accorded a range of motion and bearing capacity similar to that of the human hip in multiple gait modes.Moreover,the validity of the dynamic model and inverse kinematics were verified by comparing the theoretical and simulation results.Furthermore,with flexion and extension,the torque change in the hip prosthetic mechanism was similar to that of the human hip,which demonstrated the feasibility of the hip prosthetic mechanism and its good dynamic performance.
基金the National Natural Science Foundation of China(No.50435040)the National High Technology Research and Development Program (863) of China (No.2008AA04Z203)
文摘A five-fingered,multi-sensory and biomimetic hand is presented.The cambered palm is specially designed by utilizing the knowledge of anatomy.The position of each finger is arranged according to human hand skeleton.Each finger with three phalanges could fulfill flexion-extension movement independently.All the fingers are designed using coupling link mechanism.The location of the thumb is designed by maximizing interaction area between the thumb and other fingers.The opposite thumb could grasp along a cone surface,while maintaining its function.The hardware architecture is divided into control system and human-machine interaction system.The mechanical parts,sensors and motion control systems are integrated in the hand structure.In addition,a skin-like glove is designed,which makes the hand more humanlike.According to our primary experimental results,the hand can accomplish several grasp modes by applying an intuitive surface electromyography control scheme.The success rate of 10 modes is up to 90%.
基金Project(2009AA043803) supported by the National High Technology Research and Development Program of China Project (SKLRS200901B) supported by Self-Planned Task of State Key Laboratory of Robotics and System (Harbin Institute of Technology),ChinaProject (NCET-09-0056) supported by Program for New Century Excellent Talents in Universities of China
文摘A grasping force control strategy is proposed in order to complete various free manipulations by using anthropomorphic prosthetic hand. The position-based impedance control and force-tracking impedance control are used in free and constraint spaces, respectively. The fuzzy observer is adopted in transition in order to switch control mode. Two control modes use one position-based impedance controller. In order to achieve grasping force track, reference force is added to the impedance controller in the constraint space. Trajectory tracking in free space and torque tracking in constrained space are realized, and reliability of mode switch and stability of system are achieved. An adaptive sliding mode friction compensation method is proposed. This method makes use of terminal sliding mode idea to design sliding mode function, which makes the tracking error converge to zero in finite time and avoids the problem of conventional sliding surface that tracking error cannot converge to zero. Based on the characteristic of the exponential form friction, the sliding mode control law including the estimation of friction parameter is obtained through terminal sliding mode idea, and the online parameter update laws are obtained based on Lyapunov stability theorem. The experiments on the HIT Prosthetic Hand IV are carried out to evaluate the grasping force control strategy, and the experiment results verify the effectiveness of this control strategy.
基金Project(2008AA04Z203)supported by National High Technology Research and Development Program of China
文摘An underactuated finger structure actuated by tendon-driven system is presented.Kinematics and static analysis of the finger is done,and the results indicate that the prosthetic finger structure is effective and feasible.Based on the design of finger,a prosthetic hand is designed.The hand is composed of 5 independent fingers and it looks more like humanoid.Its size is about 85% of an adult's hand and weights about 350 g.Except the thumb finger,each finger is actuated by one DC motor,gear head and a tendon,and has three curling/extension joints.The thumb finger which is different from other existing prostheses is a novel design scheme.The thumb finger has four joints including three curling/extension joints and a joint which is used to realize the motion of the thumb related to the palm,and these joints are also driven by one DC motor,harmonic drive and a tendon.The underactuation and adaptive curling/extension motion of the finger are realized by joint torsion springs.A high-powered chip of digital signal processing(DSP)is the main part of the electrical system which is used for the motors control,data collection,communication with external controlling source,and so on.To improve the reliability of the hand,structures and sensors are designed and made as simply as possible.The hand has strong manipulation capabilities that have been verified by finger motion and grasping tests and it can satisfy the daily operational needs and psychological needs of deformities.
文摘Dear editor,Fungal endocarditis is a rare disease with a poor prognosis,suboptimal diagnostic tools responsible for long diagnostic delays in most cases,and poorly defined activity of most antifungal agents in endocarditis.^([1])The burden of diagnosis still lies with clinicians:they need a
基金supported in part by National Institutes of Health T32 AR067708,RO1CA201035the MRB Molecular Imaging Service Center(P50 CA103175)
文摘Discriminating sterile inflammation from infection, especially in cases of aseptic loosening versus an actual prosthetic joint infection, is challenging and has significant treatment implications. Our goal was to evaluate a novel human monoclonal antibody（mAb） probe directed against the Gram-positive bacterial surface molecule lipoteichoic acid（LTA）. Specificity and affinity were assessed in vitro. We then radiolabeled the anti-LTA mAb and evaluated its effectiveness as a diagnostic imaging tool for detecting infection via immuno PET imaging in an in vivo mouse model of prosthetic joint infection（PJI）. In vitro and ex vivo binding of the anti-LTA mAb to pathogenic bacteria was measured with Octet, ELISA, and flow cytometry. The in vivo PJI mouse model was assessed using traditional imaging modalities, including positron emission tomography（PET） with [^（18）F]FDG and [^（18）F]Na F as well as X-ray computed tomography（CT）, before being evaluated with the zirconium-89-labeled antibody specific for LTA（[^（89）Zr]SAC55）.The anti-LTA mAb exhibited specific binding in vitro to LTA-expressing bacteria. Results from imaging showed that our model could reliably simulate infection at the surgical site by bioluminescent imaging, conventional PET tracer imaging, and bone morphological changes by CT. One day following injection of both the radiolabeled anti-LTA and isotype control antibodies, the anti-LTA antibody demonstrated significantly greater（P 〈 0.05） uptake at S. aureus-infected prosthesis sites over either the same antibody at sterile prosthesis sites or of control non-specific antibody at infected prosthesis sites. Taken together, the radiolabeled anti-LTA mAb, [^（89）Zr]SAC55, may serve as a valuable diagnostic molecular imaging probe to help distinguish between sterile inflammation and infection in the setting of PJI. Future studies are needed to determine whether these findings will translate to human PJI.
基金Supported by t he National Natural Science Foundation of China （ No. 50435040） and the High Technology Research and Development Programme of China（ No. 2003AA420010）.
文摘We present the development of a novel prosthetic hand based on the underactuated mechanism. The aim is focused on increasing its dexterity while keeping the same dimension and weight of a traditional prosthetic device. The hybrid step motor is used as the actuator, which enables the finger to keep enough high contact torque on the grasped object with less energy consumption provided by the holding torque. The grasping force of the finger is estimated from the base joint torque, and the adoption of impedance control has provided compliance in the grasping. Also a parallel observer is used to switch over between the impedance control and the torque holding mode. The experimental results show the effectiveness of the design and control strategy.
基金Supported by Swiss National Science Foundation,No.310030_118245 and No.32003B_134963/1
文摘We present the case of a 74 year old woman suffering from severe mitral valve incompetence and rapid atrial fibrillation. After an appropriate vitamin K antagonist(VKA) therapy, the patient underwent mitral valve replacement by bioprosthesis. Then, the patient was rehospitalized for jaundice. Suspecting hepatotoxicity, VKA was discontinued and fondaparinux was started. During this treatment, the patient developed a symptomatic atrial thrombus. After exclusion of a hepatic disease, VKA was re-established with hemodynamic and liver enzymes normalization and atrial thrombus resolution. Caution has to be used when considering fondaparinux as an alternative strategy to VKA in patients with multiple thrombotic risk factors.
