Background The purpose of otomicrosurgery in modern times is to achieve complete removal of disease,which is the basis for hearing rehabilitation.Artificial ossicles are important for hearing rehabilitation.One of the...Background The purpose of otomicrosurgery in modern times is to achieve complete removal of disease,which is the basis for hearing rehabilitation.Artificial ossicles are important for hearing rehabilitation.One of the materials is hydroxyapatite that acts as ossicular replacement prosthesis(HA prosthesis,PORP&TORP)and is commonly used as substitute bone in clinics.Although HA prostheses feature good biocompatibility,stability and certain resistance to infection,the structure of the material can be decomposed and absorbed.Based upon animal experiments and clinical application,this article explores the infectivity of HA prostheses and influencing factors.Materials and Methods HA prostheses were implanted in the bulla in guinea pigs.Infected HA prostheses were examined under a scanning electron microscope.Ninety patients implanted with HA prostheses were followed for more than 3 months.Five cases that had undergone revision operations were reported.Results Scanning electronic microscopy showed that the normal compact structures had disappeared and become loose in infected HA prostheses,with their micropores infiltrated with effusion,fibrous tissue and inflammatory cells.As a result,the normal ceramic structure was decomposed and the micropores structure disappeared.The infected mesotympanum in the reported cases also led to HA infection.The shape and structure of bone were destroyed,which was visible by visual examination and light microscopy.The process of cholesteatoma recurrence was always associated with infection,although the HA prosthesis was sometimes spared.Conclusion While HA prosthesis is anti-infective to some extent,long-term infection and cholesteatoma recurrence can lead to destruction and decomposition of HA prostheses.Long-term infected middle ear cavity,dysfunctional Eustachian tube,residual and recurrent cholesteatoma and other factors can cause decomposition of HA prosthesis and result in hearing loss.展开更多
Cases of widespread bone hydatid infection are relatively rare in clinical practice.In this study,we reported for the first time a validated integrated repair therapy for multiple bone tissues,including the hip,femur,...Cases of widespread bone hydatid infection are relatively rare in clinical practice.In this study,we reported for the first time a validated integrated repair therapy for multiple bone tissues,including the hip,femur,and knee,caused by echinococ cosis.Artificial intelligence(AI)was used to develop a targeted surgical plan and to design a personalized prosthesis.Finite element analysis(FEA)was used to optimize the mechanical effectiveness of a customized integrated replacement prosthesis and to model stress distribution in the surrounding bone.Three-dimensional(3 D)printing was used to fabricate a customized prosthesis.With the assistance of AI,FEA,and 3 D printing technology,a personalized surgical plan and customized prosthesis were successfully constructed based on the patient’s disease.This approach achieved a successful therapeutic effect,demonstrating that AI-assisted personalized medicine holds great promise for the future.展开更多
Background:Inflatable Penile Prosthesis(IPP)is the treatment for erectile dysfunction(ED)refractory to pharmacological therapies.Long-term data on factors associated with prosthesis survival remain unclear.This study ...Background:Inflatable Penile Prosthesis(IPP)is the treatment for erectile dysfunction(ED)refractory to pharmacological therapies.Long-term data on factors associated with prosthesis survival remain unclear.This study aimed to analyze the long-term survival of penile prostheses and identify risk factors associated with survival without reintervention.Methods:This is a retrospective,single-center study of patients who underwent IPP implantation between January 2014 and December 2022.Preoperative data related to the patient and the etiology of ED,as well as perioperative data,were collected.The primary outcome was survival without reintervention,defined as prosthesis revision or explantation due to mechanical dysfunction or infection.We conducted survival analyses without reintervention and searched for risk factors using a multivariate Cox model.Results:In total,33 out of 137 patients underwent reintervention(24.1%),including 24(17.5%)prosthesis revisions and 9(6.6%)had explantations.Median follow-up was 39 months with an interquartile range(IQR)of 9.00 to 62.00.Median survival without reintervention was 7 years.In univariate analysis,downsizing(p=0.046)was associated with reintervention.Smoking(p=0.003)and age(p=0.034)were associated with prosthesis explantation.The number of implantations(p=0.009)was associated with prosthesis revision.Multivariate analysis by the Cox model did not identify any independent predictive factors for reintervention.Conclusion:Smoking may play a role in infection post-IPP implantation.Primary implantations seem to be associated with better survival.Adjusting cylinder size,known as downsizing,is likely to be a proxy for the complexity of the procedure and thus linked to earlier reintervention.展开更多
Maxillary bone loss impairs essential functions (chewing, swallowing, speech) and gives patients a very unaesthetic appearance due to the removal of facial support tissues, leading to serious psychological consequence...Maxillary bone loss impairs essential functions (chewing, swallowing, speech) and gives patients a very unaesthetic appearance due to the removal of facial support tissues, leading to serious psychological consequences. Treatment is multidisciplinary and requires a resective surgery if the cause is tumor-related, or an additive surgery if the cause is traumatic. This article aims to show the role of making a prosthesis to restore function (chewing, swallowing, speech) and aesthetics following maxillary bone loss. We will eighter present a clinical case involving a right maxillary tumor that was surgically resected followed by radiotherapy, and subsequently rehabilitated with a maxillofacial prosthesis in the consultation and dental treatment center of the university hospital center of Casablanca.展开更多
This paper presents an innovative design of a Bionic Powered Ankle Prosthesis(BPAP)utilizing a muscle recruitment mechanism-inspired clutch,aimed at achieving biomimetic simulation of ankle muscle function.To address ...This paper presents an innovative design of a Bionic Powered Ankle Prosthesis(BPAP)utilizing a muscle recruitment mechanism-inspired clutch,aimed at achieving biomimetic simulation of ankle muscle function.To address the varying stiffness requirements of the prosthesis across different gaits,the clutch dynamically switch between different rope bundle combinations.The mechanical characteristics during the load traction process of the selected flexible ropes are also studied.A mathematical model of the series elastic drive system is established.The optimization is carried out with the minimum peak power required by the motor as the optimization goal.The experimental results show that by applying a clutch with human muscle recruitment mechanism,the proposed prosthesis can achieve better energy efficiency at different speeds.展开更多
Human vision,confined to visible wavelengths,represents a mere fraction of the electromagnetic spectrum exploited by other species.Pit vipers detect infrared radiation through specialized pit organs,integrating therma...Human vision,confined to visible wavelengths,represents a mere fraction of the electromagnetic spectrum exploited by other species.Pit vipers detect infrared radiation through specialized pit organs,integrating thermal and visual data to navigate darkness[1].Conventional retinal prosthetics,limited to visible light and requiring external power or injectable nanomaterials,fail to address this sensory deficit[2–5].展开更多
In order to improve the quality of the bio-active coating on medical grade CoNiCrMo substrate, hydroxyapatite(HA) coatings were produced via low-temperature dip-coating route on substrates treated using various surfac...In order to improve the quality of the bio-active coating on medical grade CoNiCrMo substrate, hydroxyapatite(HA) coatings were produced via low-temperature dip-coating route on substrates treated using various surface pre-treating methods. The surface and cross-sectional morphologies of HA coatings were observed by SEM, as well as the bonding strength between coatings and substrates after different pre-treatments were characterized according to ASTM C633. The low-temperature HA dip-coating method with the substrate merely oxidized at 600℃ can provide a high quality HA coating for CoNiCrMo, of which the bonding strength reaches (58±5)MPa, higher than that of the clinically used HA coatings on Ti-alloys produced via plasma spray route, as well as a HA coating with full crystallinity and high phase-purity, which is more in-vivo stable than plasma sprayed HA coating.展开更多
Hydroxyapatite nanoparticles(HAP NPs)were synthesized by a one‐step hydrothermal method.The surface of HAP NPs was grafted-SH and-COOH chelating groups via in situ surface‐modification with iminodiacetic acid(IDA)an...Hydroxyapatite nanoparticles(HAP NPs)were synthesized by a one‐step hydrothermal method.The surface of HAP NPs was grafted-SH and-COOH chelating groups via in situ surface‐modification with iminodiacetic acid(IDA)and 3‐mercaptopropyl trimethoxysilane(MPS)to afford dual surface‐capped nano‐amendment HAPIDA/MPS.The structure of HAP‐IDA/MPS was characterized,and its adsorption performance for Hg^(2+),Cu^(2+),Zn^(2+),Ni^(2+),Co^(2+),and Cd^(2+)was evaluated.The total adsorption capacity of 0.10 g HAP‐IDA/MPS nano‐amendment for Hg^(2+),Cu^(2+),Zn^(2+),Ni^(2+),Co^(2+),and Cd^(2+)with an initial mass concentration of 20 mg·L^(-1) reached 13.7 mg·g^(-1),about 4.3 times as much as that of HAP.Notably,HAP‐IDA/MPS nano‐amendment displayed the highest immobilization rate for Hg^(2+),possibly because of its chemical reaction with-SH to form sulfide,possessing the lowest solubility product constant among a variety of metal sulfides.展开更多
Retinal degenerative diseases may induce the degeneration of outer retina and in turn,blindness.Nevertheless,due to the maintenance of inner retina,the coding and processing of visual neurons responses are still able ...Retinal degenerative diseases may induce the degeneration of outer retina and in turn,blindness.Nevertheless,due to the maintenance of inner retina,the coding and processing of visual neurons responses are still able to be executed naturally.Therefore,an effective retinal prosthesis device may be developed by mimicking the function of outer retina:transferring the visual light into artificial stimulus and delivering the stimulus to the retina aiming to evoke the neural responses.As two main developing directions for current retinal prosthesis,epiretinal(ER)and subretinal(SR)prosthesis are both undergoing experimental stage and possessing advantages and limitations.Further investigations in power supply,biocompatibility,etc.are still required.Additionally,suprachoroidal transretinal stimulation(STS)and neurotransmitter-induced stimulation as some other alternatives in retinal prosthesis are also considered as promising research directions,although they are not mature enough to be applied commercially,either.展开更多
Hydroxyapatite (HA) is widely explored as a biocompatible filler to enhance the mechanical and functional properties of glass ionomer cements (GICs). HA of particle sizes 15 µm and 30 µm were added as a fill...Hydroxyapatite (HA) is widely explored as a biocompatible filler to enhance the mechanical and functional properties of glass ionomer cements (GICs). HA of particle sizes 15 µm and 30 µm were added as a filler into a matrix, composed of calcium aluminosilicate GICs and Poly-acrylic acid (PAA) in varying ratios. The tested ratios were Glass:PAA = 2:1 and Glass:HA:PAA = 2:0.5:1 to improve the mechanical strength of a conventional GIC. Mechanical properties, including compressive, flexural, and diametral tensile strength were studied at different setting times. The compressive strength (CS) was improved with hydroxyapatite addition and prolonged setting time while diametral tensile strength (DTS) did not follow any specific trend. The flexural strength (FS) of the composite cement was increased with increasing setting time regardless of the particle size of hydroxyapatite. The FTIR spectra of hydroxyapatite of particle sizes 15 μm and 30 μm are similar but for HA-GIC composites, the FTIR spectra, the peak around 1460 cm−1 are due to C-H and the peak at 1553 cm−1 is due to calcium carboxylate with calcium in a bridging mode which would be an excellent material that chemically bonds to the tooth structure, making it effective for both restorative procedures and cavity fillings. Scanning electron microscopy (SEM) microstructural study revealed that the glass particles were wrenched out, which was a cohesive fracture. The X-ray diffraction (XRD) pattern showed that the hydroxyapatite has a crystalline single-phase, hexagonal structure. The sharp peaks between the 2-theta range of 30 - 40 degrees are the same as in enamel powder. The spectra indicate the pure set cement as amorphous since there is no prominent peak, but with the addition of hydroxyapatite filler, the peak in the 2-theta range of 20 - 35 degrees is ascribed to crystalline apatite structure. The results indicate that incorporating hydroxyapatite into GIC significantly enhances its mechanical properties and structural integrity, suggesting its potential as an improved material for dental and restorative applications.展开更多
A new type of testicular prosthesis made of silastic with an elliptical shape to mimic a normal testis was developed by our team and submitted for patenting in China. The prosthesis was produced in different sizes to ...A new type of testicular prosthesis made of silastic with an elliptical shape to mimic a normal testis was developed by our team and submitted for patenting in China. The prosthesis was produced in different sizes to imitate the normal testis of the patient. To investigate the effects and safety of the testicular prosthesis, 20 patients receiving testicular prosthesis implantation were recruited for this study. Follow-up after 6 months revealed no complications in the patients. All the patients answered that they were satisfied with their body image and the position of the implants, 19 patients were satisfied with the size and 16 patients were satisfied with the weight. These results show that the testicular prosthesis used in this study can meet patient＇s expectations. Patients undergoing orchiectomy should be offered the option to receive a testicular prosthesis implantation. The dimensions and weight of the available prosthetic implants should be further addressed to improve patient satisfaction.展开更多
Fluorine-doped hydroxyapatite(FHA) and calcium deficient hydroxyapatite(CDHA) were coated on the surface biodegradable magnesium alloy using electrochemical deposition(ED) technique. Coating characterization was inves...Fluorine-doped hydroxyapatite(FHA) and calcium deficient hydroxyapatite(CDHA) were coated on the surface biodegradable magnesium alloy using electrochemical deposition(ED) technique. Coating characterization was investigated X-ray diffraction(XRD), Fourier-transformed infrared spectroscopy(FTIR), transmission electron microscopy(TEM), scanni electron microscopy(SEM) and energy dispersive X-ray spectroscopy(EDS). The result shows that nano-FHA coated samp presents nano needle-like structure, which is oriented perpendicular to the surface of the substrate with denser and more unifo layers compared to the nano-CDHA coated sample. The nano-FHA coating shows smaller crystallite size(65 nm) compared to t nano-CDHA coating(95 nm); however, CDHA presents thicker layer(19 μm in thickness) compared to the nano-FHA(15 μm thickness). The corrosion behaviour determined by polarization, immersion and hydrogen evolution tests indicates that the nano-FH and nano-CDHA coatings significantly decrease corrosion rate and induce passivation. The nano-FHA and nano-CDHA coatings c accelerate the formation of bone-like apatite layer and significantly decrease the dissolution rate as compared to the uncoated M alloy. The nano-FHA coating provides effective protection to Mg alloy and presents the highest corrosion resistance. Therefore, t nano-FHA coating on Mg alloy is suggested as a great candidate for orthopaedic applications.展开更多
The article highlights a new method for the fabrication of an ocular prosthesis by the incorporation of a ceramic scleral veneer. The steps of fabrication include impression making, wax try-in, performing a “cut-back...The article highlights a new method for the fabrication of an ocular prosthesis by the incorporation of a ceramic scleral veneer. The steps of fabrication include impression making, wax try-in, performing a “cut-back” on a selected stock eye, insertion of the IPS e-max press scleral veneer, finishing and insertion. It also includes a detailed review on non-integrated ocular prostheses.展开更多
A pulse frequency modulation（PFM） circuit for retinal prosthesis,which generates electrical pulses with frequency proportional to the intensity of incident light, is presented. The fundamental characteristic of the ...A pulse frequency modulation（PFM） circuit for retinal prosthesis,which generates electrical pulses with frequency proportional to the intensity of incident light, is presented. The fundamental characteristic of the circuit is described and analyzed. The circuit is realized in 0.6μm CMOS process,and the simulation results testify to the possibility of sub-retinal implantation.展开更多
The CAD model of molar prosthesis is usually stored in standard templete library （STIr） format. A new topological structure is given based on STL format and the vertex-based entity offset algorithm is presented to r...The CAD model of molar prosthesis is usually stored in standard templete library （STIr） format. A new topological structure is given based on STL format and the vertex-based entity offset algorithm is presented to realize the rapid generation of roughing/finishing tool path for molar prosthesis. Simulation results show that the proposed algorithm prossesses characteristics of excellent stabilization, fast calculation speed and high machining accuracy.展开更多
Total loss of talus due to trauma or avascular necrosis,for example,still remains to be a major challenge in foot and ankle surgery with severely limited treatment options.Implantation of a custom made total talar pro...Total loss of talus due to trauma or avascular necrosis,for example,still remains to be a major challenge in foot and ankle surgery with severely limited treatment options.Implantation of a custom made total talar prosthesis has shown promising results so far.Most important factors for long time success are degree of congruence of articular surfaces and ligamentous stability of the ankle.Therefore,our aim was to develop an optimized custom made prosthesis for total talus replacement providing a high level of primary stability.A custom made hemiprosthesis was developed using computed tomography and magnetic resonance imaging data of the affected and contralateral talus considering the principles and technology for the development of the S.T.A.R.prosthesis(Stryker).Additionally,four eyelets for fixation of artificial ligaments were added at the correspondent footprints of the most important ligaments.Two modifications can be provided according to the clinical requirements:A tri-articular hemiprosthesis or a bi-articular hemiprosthesis combined with the tibial component of the S.T.A.R.total ankle replacement system.A feasibility study was performed using a fresh frozen human cadaver.Maximum range of motion of the ankle was measured and ligamentous stability was evaluated by use of standard X-rays after application of varus,valgus or sagittal stress with 150 N.Correct implantation of the prosthesis was technically possible via an anterior approach to the ankle and using standard instruments.Malleolar osteotomies were not required.Maximum ankle dorsiflexion and plantarflexion were measured as 22-0-28 degrees.Maximum anterior displacement of the talus was 6 mm,maximum varus tilt 3 degrees and maximum valgus tilt 2 degrees.Application of an internally braced prosthesis for total talus replacement in humans is technically feasible and might be a reasonable procedure in carefully selected cases with no better alternatives left.展开更多
The total hip replacement rationale, since 1960 when it was introduced by Sir Charnley, has been modified and evolved until nowadays thanks to laboratory research and clinical trials. This evolution followed a guideli...The total hip replacement rationale, since 1960 when it was introduced by Sir Charnley, has been modified and evolved until nowadays thanks to laboratory research and clinical trials. This evolution followed a guideline whose milestones are: 1) the surgical approach and implantation technique (ex: detachment of the greater trochanter);2) to use or not to use cement;3) the evolution of materials (titanium, ceramic, x-linked polyethylene);4) the identification of the debris-disease rather than the cement-disease;5) studies focused on bone-prosthesis interaction and biological phenomena related. Between those studies, the authors consider crucial the introduction of tissue sparing surgery and femoral neck preserving rationale, concepts to which they have devoted their scientific research and clinical experience for over the last 30 years, from 1980 to nowadays.展开更多
It is important for surgeons performing sarcoma surgery to know that bone resection and tumor prosthesis applications in soft tissue sarcomas(STS)have unique features in terms of indication,surgical approach and follo...It is important for surgeons performing sarcoma surgery to know that bone resection and tumor prosthesis applications in soft tissue sarcomas(STS)have unique features in terms of indication,surgical approach and follow-up,in terms of the management of these cases.Some STS are associated with bone and major neurovascular structures.Bone-associated STS are generally relatively large and relatively deep-seated.Additionally,the tendency for metastasis is high.In some cases,the decision about which structures to resect is difficult.These cases are often accompanied by poor oncological and surgical outcomes.Management of cases should be done by a multidisciplinary team in advanced centers specialized in this field.The surgical team must have sufficient knowledge and experience in the field of limb-sparing surgery.Preoperative evaluation and especially good planning of bone and soft tissue reconstruction are vital.展开更多
文摘Background The purpose of otomicrosurgery in modern times is to achieve complete removal of disease,which is the basis for hearing rehabilitation.Artificial ossicles are important for hearing rehabilitation.One of the materials is hydroxyapatite that acts as ossicular replacement prosthesis(HA prosthesis,PORP&TORP)and is commonly used as substitute bone in clinics.Although HA prostheses feature good biocompatibility,stability and certain resistance to infection,the structure of the material can be decomposed and absorbed.Based upon animal experiments and clinical application,this article explores the infectivity of HA prostheses and influencing factors.Materials and Methods HA prostheses were implanted in the bulla in guinea pigs.Infected HA prostheses were examined under a scanning electron microscope.Ninety patients implanted with HA prostheses were followed for more than 3 months.Five cases that had undergone revision operations were reported.Results Scanning electronic microscopy showed that the normal compact structures had disappeared and become loose in infected HA prostheses,with their micropores infiltrated with effusion,fibrous tissue and inflammatory cells.As a result,the normal ceramic structure was decomposed and the micropores structure disappeared.The infected mesotympanum in the reported cases also led to HA infection.The shape and structure of bone were destroyed,which was visible by visual examination and light microscopy.The process of cholesteatoma recurrence was always associated with infection,although the HA prosthesis was sometimes spared.Conclusion While HA prosthesis is anti-infective to some extent,long-term infection and cholesteatoma recurrence can lead to destruction and decomposition of HA prostheses.Long-term infected middle ear cavity,dysfunctional Eustachian tube,residual and recurrent cholesteatoma and other factors can cause decomposition of HA prosthesis and result in hearing loss.
基金partially supported by the National Natural Science Foundation of China(Nos.32471474 and 82102574)the Precision Medicine Project of People’s Hospital of Xinjiang Uygur Autonomous Region(No.20220305)+4 种基金Chengdu Advanced Metal Materials Industry Technology Research Institute Co.,Ltd.Support Project(No.24H0802)Sichuan Science and Technology Program(Nos.2025YFHZ0086,2023YFS0053,2024YFHZ0125,and 2025ZNSFSC0381)Project of Tianfu Jincheng Laboratory(No.2025ZH009)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515220102)Xinjiang Autonomous Region Science and Technology Support Project Plan(Directive)Project(No.2024E02049)。
文摘Cases of widespread bone hydatid infection are relatively rare in clinical practice.In this study,we reported for the first time a validated integrated repair therapy for multiple bone tissues,including the hip,femur,and knee,caused by echinococ cosis.Artificial intelligence(AI)was used to develop a targeted surgical plan and to design a personalized prosthesis.Finite element analysis(FEA)was used to optimize the mechanical effectiveness of a customized integrated replacement prosthesis and to model stress distribution in the surrounding bone.Three-dimensional(3 D)printing was used to fabricate a customized prosthesis.With the assistance of AI,FEA,and 3 D printing technology,a personalized surgical plan and customized prosthesis were successfully constructed based on the patient’s disease.This approach achieved a successful therapeutic effect,demonstrating that AI-assisted personalized medicine holds great promise for the future.
文摘Background:Inflatable Penile Prosthesis(IPP)is the treatment for erectile dysfunction(ED)refractory to pharmacological therapies.Long-term data on factors associated with prosthesis survival remain unclear.This study aimed to analyze the long-term survival of penile prostheses and identify risk factors associated with survival without reintervention.Methods:This is a retrospective,single-center study of patients who underwent IPP implantation between January 2014 and December 2022.Preoperative data related to the patient and the etiology of ED,as well as perioperative data,were collected.The primary outcome was survival without reintervention,defined as prosthesis revision or explantation due to mechanical dysfunction or infection.We conducted survival analyses without reintervention and searched for risk factors using a multivariate Cox model.Results:In total,33 out of 137 patients underwent reintervention(24.1%),including 24(17.5%)prosthesis revisions and 9(6.6%)had explantations.Median follow-up was 39 months with an interquartile range(IQR)of 9.00 to 62.00.Median survival without reintervention was 7 years.In univariate analysis,downsizing(p=0.046)was associated with reintervention.Smoking(p=0.003)and age(p=0.034)were associated with prosthesis explantation.The number of implantations(p=0.009)was associated with prosthesis revision.Multivariate analysis by the Cox model did not identify any independent predictive factors for reintervention.Conclusion:Smoking may play a role in infection post-IPP implantation.Primary implantations seem to be associated with better survival.Adjusting cylinder size,known as downsizing,is likely to be a proxy for the complexity of the procedure and thus linked to earlier reintervention.
文摘Maxillary bone loss impairs essential functions (chewing, swallowing, speech) and gives patients a very unaesthetic appearance due to the removal of facial support tissues, leading to serious psychological consequences. Treatment is multidisciplinary and requires a resective surgery if the cause is tumor-related, or an additive surgery if the cause is traumatic. This article aims to show the role of making a prosthesis to restore function (chewing, swallowing, speech) and aesthetics following maxillary bone loss. We will eighter present a clinical case involving a right maxillary tumor that was surgically resected followed by radiotherapy, and subsequently rehabilitated with a maxillofacial prosthesis in the consultation and dental treatment center of the university hospital center of Casablanca.
基金supported in part by National Natural Science Foundation of China[Grant No.62203356].
文摘This paper presents an innovative design of a Bionic Powered Ankle Prosthesis(BPAP)utilizing a muscle recruitment mechanism-inspired clutch,aimed at achieving biomimetic simulation of ankle muscle function.To address the varying stiffness requirements of the prosthesis across different gaits,the clutch dynamically switch between different rope bundle combinations.The mechanical characteristics during the load traction process of the selected flexible ropes are also studied.A mathematical model of the series elastic drive system is established.The optimization is carried out with the minimum peak power required by the motor as the optimization goal.The experimental results show that by applying a clutch with human muscle recruitment mechanism,the proposed prosthesis can achieve better energy efficiency at different speeds.
基金supported by the National Key Research and Development Program from Ministry of Science and Technology(No.2023YFB3208102).
文摘Human vision,confined to visible wavelengths,represents a mere fraction of the electromagnetic spectrum exploited by other species.Pit vipers detect infrared radiation through specialized pit organs,integrating thermal and visual data to navigate darkness[1].Conventional retinal prosthetics,limited to visible light and requiring external power or injectable nanomaterials,fail to address this sensory deficit[2–5].
文摘In order to improve the quality of the bio-active coating on medical grade CoNiCrMo substrate, hydroxyapatite(HA) coatings were produced via low-temperature dip-coating route on substrates treated using various surface pre-treating methods. The surface and cross-sectional morphologies of HA coatings were observed by SEM, as well as the bonding strength between coatings and substrates after different pre-treatments were characterized according to ASTM C633. The low-temperature HA dip-coating method with the substrate merely oxidized at 600℃ can provide a high quality HA coating for CoNiCrMo, of which the bonding strength reaches (58±5)MPa, higher than that of the clinically used HA coatings on Ti-alloys produced via plasma spray route, as well as a HA coating with full crystallinity and high phase-purity, which is more in-vivo stable than plasma sprayed HA coating.
文摘Hydroxyapatite nanoparticles(HAP NPs)were synthesized by a one‐step hydrothermal method.The surface of HAP NPs was grafted-SH and-COOH chelating groups via in situ surface‐modification with iminodiacetic acid(IDA)and 3‐mercaptopropyl trimethoxysilane(MPS)to afford dual surface‐capped nano‐amendment HAPIDA/MPS.The structure of HAP‐IDA/MPS was characterized,and its adsorption performance for Hg^(2+),Cu^(2+),Zn^(2+),Ni^(2+),Co^(2+),and Cd^(2+)was evaluated.The total adsorption capacity of 0.10 g HAP‐IDA/MPS nano‐amendment for Hg^(2+),Cu^(2+),Zn^(2+),Ni^(2+),Co^(2+),and Cd^(2+)with an initial mass concentration of 20 mg·L^(-1) reached 13.7 mg·g^(-1),about 4.3 times as much as that of HAP.Notably,HAP‐IDA/MPS nano‐amendment displayed the highest immobilization rate for Hg^(2+),possibly because of its chemical reaction with-SH to form sulfide,possessing the lowest solubility product constant among a variety of metal sulfides.
文摘Retinal degenerative diseases may induce the degeneration of outer retina and in turn,blindness.Nevertheless,due to the maintenance of inner retina,the coding and processing of visual neurons responses are still able to be executed naturally.Therefore,an effective retinal prosthesis device may be developed by mimicking the function of outer retina:transferring the visual light into artificial stimulus and delivering the stimulus to the retina aiming to evoke the neural responses.As two main developing directions for current retinal prosthesis,epiretinal(ER)and subretinal(SR)prosthesis are both undergoing experimental stage and possessing advantages and limitations.Further investigations in power supply,biocompatibility,etc.are still required.Additionally,suprachoroidal transretinal stimulation(STS)and neurotransmitter-induced stimulation as some other alternatives in retinal prosthesis are also considered as promising research directions,although they are not mature enough to be applied commercially,either.
文摘Hydroxyapatite (HA) is widely explored as a biocompatible filler to enhance the mechanical and functional properties of glass ionomer cements (GICs). HA of particle sizes 15 µm and 30 µm were added as a filler into a matrix, composed of calcium aluminosilicate GICs and Poly-acrylic acid (PAA) in varying ratios. The tested ratios were Glass:PAA = 2:1 and Glass:HA:PAA = 2:0.5:1 to improve the mechanical strength of a conventional GIC. Mechanical properties, including compressive, flexural, and diametral tensile strength were studied at different setting times. The compressive strength (CS) was improved with hydroxyapatite addition and prolonged setting time while diametral tensile strength (DTS) did not follow any specific trend. The flexural strength (FS) of the composite cement was increased with increasing setting time regardless of the particle size of hydroxyapatite. The FTIR spectra of hydroxyapatite of particle sizes 15 μm and 30 μm are similar but for HA-GIC composites, the FTIR spectra, the peak around 1460 cm−1 are due to C-H and the peak at 1553 cm−1 is due to calcium carboxylate with calcium in a bridging mode which would be an excellent material that chemically bonds to the tooth structure, making it effective for both restorative procedures and cavity fillings. Scanning electron microscopy (SEM) microstructural study revealed that the glass particles were wrenched out, which was a cohesive fracture. The X-ray diffraction (XRD) pattern showed that the hydroxyapatite has a crystalline single-phase, hexagonal structure. The sharp peaks between the 2-theta range of 30 - 40 degrees are the same as in enamel powder. The spectra indicate the pure set cement as amorphous since there is no prominent peak, but with the addition of hydroxyapatite filler, the peak in the 2-theta range of 20 - 35 degrees is ascribed to crystalline apatite structure. The results indicate that incorporating hydroxyapatite into GIC significantly enhances its mechanical properties and structural integrity, suggesting its potential as an improved material for dental and restorative applications.
文摘A new type of testicular prosthesis made of silastic with an elliptical shape to mimic a normal testis was developed by our team and submitted for patenting in China. The prosthesis was produced in different sizes to imitate the normal testis of the patient. To investigate the effects and safety of the testicular prosthesis, 20 patients receiving testicular prosthesis implantation were recruited for this study. Follow-up after 6 months revealed no complications in the patients. All the patients answered that they were satisfied with their body image and the position of the implants, 19 patients were satisfied with the size and 16 patients were satisfied with the weight. These results show that the testicular prosthesis used in this study can meet patient＇s expectations. Patients undergoing orchiectomy should be offered the option to receive a testicular prosthesis implantation. The dimensions and weight of the available prosthetic implants should be further addressed to improve patient satisfaction.
文摘Fluorine-doped hydroxyapatite(FHA) and calcium deficient hydroxyapatite(CDHA) were coated on the surface biodegradable magnesium alloy using electrochemical deposition(ED) technique. Coating characterization was investigated X-ray diffraction(XRD), Fourier-transformed infrared spectroscopy(FTIR), transmission electron microscopy(TEM), scanni electron microscopy(SEM) and energy dispersive X-ray spectroscopy(EDS). The result shows that nano-FHA coated samp presents nano needle-like structure, which is oriented perpendicular to the surface of the substrate with denser and more unifo layers compared to the nano-CDHA coated sample. The nano-FHA coating shows smaller crystallite size(65 nm) compared to t nano-CDHA coating(95 nm); however, CDHA presents thicker layer(19 μm in thickness) compared to the nano-FHA(15 μm thickness). The corrosion behaviour determined by polarization, immersion and hydrogen evolution tests indicates that the nano-FH and nano-CDHA coatings significantly decrease corrosion rate and induce passivation. The nano-FHA and nano-CDHA coatings c accelerate the formation of bone-like apatite layer and significantly decrease the dissolution rate as compared to the uncoated M alloy. The nano-FHA coating provides effective protection to Mg alloy and presents the highest corrosion resistance. Therefore, t nano-FHA coating on Mg alloy is suggested as a great candidate for orthopaedic applications.
文摘The article highlights a new method for the fabrication of an ocular prosthesis by the incorporation of a ceramic scleral veneer. The steps of fabrication include impression making, wax try-in, performing a “cut-back” on a selected stock eye, insertion of the IPS e-max press scleral veneer, finishing and insertion. It also includes a detailed review on non-integrated ocular prostheses.
文摘A pulse frequency modulation（PFM） circuit for retinal prosthesis,which generates electrical pulses with frequency proportional to the intensity of incident light, is presented. The fundamental characteristic of the circuit is described and analyzed. The circuit is realized in 0.6μm CMOS process,and the simulation results testify to the possibility of sub-retinal implantation.
文摘The CAD model of molar prosthesis is usually stored in standard templete library （STIr） format. A new topological structure is given based on STL format and the vertex-based entity offset algorithm is presented to realize the rapid generation of roughing/finishing tool path for molar prosthesis. Simulation results show that the proposed algorithm prossesses characteristics of excellent stabilization, fast calculation speed and high machining accuracy.
文摘Total loss of talus due to trauma or avascular necrosis,for example,still remains to be a major challenge in foot and ankle surgery with severely limited treatment options.Implantation of a custom made total talar prosthesis has shown promising results so far.Most important factors for long time success are degree of congruence of articular surfaces and ligamentous stability of the ankle.Therefore,our aim was to develop an optimized custom made prosthesis for total talus replacement providing a high level of primary stability.A custom made hemiprosthesis was developed using computed tomography and magnetic resonance imaging data of the affected and contralateral talus considering the principles and technology for the development of the S.T.A.R.prosthesis(Stryker).Additionally,four eyelets for fixation of artificial ligaments were added at the correspondent footprints of the most important ligaments.Two modifications can be provided according to the clinical requirements:A tri-articular hemiprosthesis or a bi-articular hemiprosthesis combined with the tibial component of the S.T.A.R.total ankle replacement system.A feasibility study was performed using a fresh frozen human cadaver.Maximum range of motion of the ankle was measured and ligamentous stability was evaluated by use of standard X-rays after application of varus,valgus or sagittal stress with 150 N.Correct implantation of the prosthesis was technically possible via an anterior approach to the ankle and using standard instruments.Malleolar osteotomies were not required.Maximum ankle dorsiflexion and plantarflexion were measured as 22-0-28 degrees.Maximum anterior displacement of the talus was 6 mm,maximum varus tilt 3 degrees and maximum valgus tilt 2 degrees.Application of an internally braced prosthesis for total talus replacement in humans is technically feasible and might be a reasonable procedure in carefully selected cases with no better alternatives left.
文摘The total hip replacement rationale, since 1960 when it was introduced by Sir Charnley, has been modified and evolved until nowadays thanks to laboratory research and clinical trials. This evolution followed a guideline whose milestones are: 1) the surgical approach and implantation technique (ex: detachment of the greater trochanter);2) to use or not to use cement;3) the evolution of materials (titanium, ceramic, x-linked polyethylene);4) the identification of the debris-disease rather than the cement-disease;5) studies focused on bone-prosthesis interaction and biological phenomena related. Between those studies, the authors consider crucial the introduction of tissue sparing surgery and femoral neck preserving rationale, concepts to which they have devoted their scientific research and clinical experience for over the last 30 years, from 1980 to nowadays.
文摘It is important for surgeons performing sarcoma surgery to know that bone resection and tumor prosthesis applications in soft tissue sarcomas(STS)have unique features in terms of indication,surgical approach and follow-up,in terms of the management of these cases.Some STS are associated with bone and major neurovascular structures.Bone-associated STS are generally relatively large and relatively deep-seated.Additionally,the tendency for metastasis is high.In some cases,the decision about which structures to resect is difficult.These cases are often accompanied by poor oncological and surgical outcomes.Management of cases should be done by a multidisciplinary team in advanced centers specialized in this field.The surgical team must have sufficient knowledge and experience in the field of limb-sparing surgery.Preoperative evaluation and especially good planning of bone and soft tissue reconstruction are vital.
