We present a systematical study on comparison between water and dry coupling in photoacoustic tomography of the humanfinger joints.Compared to the direct water immersion of thefinger for water coupling,the dry couplin...We present a systematical study on comparison between water and dry coupling in photoacoustic tomography of the humanfinger joints.Compared to the direct water immersion of thefinger for water coupling,the dry coupling is realized through a transparent PDMSfilm-based water bag,which ensures water-free contact with the skin.The results obtained suggest that the dry cou-pling provides image quality comparable to that by water coupling while eliminating the wrin-kling of thefinger joint caused by the water immersion.In addition,the dry coupling offers more stable hemodynamic images than the water coupling as the water immersion of thefinger joint causes reduction in blood vessel size.展开更多
This study was undertaken to determine the bending strength properties of off-cut Yellow Meranti wood by applying the finger jointed techniques. The finger orientations that were used in this study are vertical and ho...This study was undertaken to determine the bending strength properties of off-cut Yellow Meranti wood by applying the finger jointed techniques. The finger orientations that were used in this study are vertical and horizontal finger orientation. Specimens were bonded with PVAc （polyvinyl acetate）. The bending strength properties were determined by the three point and four point bending test method. The results show that vertical finger orientation has the higher mean of modulus of rupture and the modulus of elasticity value of 24.49 MPa （28.91 MPa） and 8,814 MPa （11,668 MPa） respectively. However, the tested specimen properties did not meet the minimum strength of the solid （control） specimens.展开更多
Trauma, osteoarthritis and rheumatoid arthritis can destroy the articulating cartilage in small and large joints, especially in the metacarpo [tarso] phalangeal (MCP/MTP) and phalangeal-phalangeal (PIP) joints. Single...Trauma, osteoarthritis and rheumatoid arthritis can destroy the articulating cartilage in small and large joints, especially in the metacarpo [tarso] phalangeal (MCP/MTP) and phalangeal-phalangeal (PIP) joints. Single piece finger prosthetic designs can reduce pain and correct aesthetic issues, with problems on contemporary designs including decreased stability, lack of fixation and loss of functionality. The examined implants are representative models of currently available total joint replacement (TJR) designs for MCP replacement, such as the Swanson one piece implant. These implants have been shown clinically to have a high failure rate (up to 90%), but the cause of failure is unknown. Compressive studies using a 50 N force and medial-lateral loads of 50 N perpendicular to the longitudinal axis of the arms of the implant were individually applied. Due to material failings, lower values had to be used in some cases. Maximum stress values were found for flexion loading;the Swanson approximation had a peak stress of 8.71 GPa at the interface of the joint arm and the flexion center, Neuflex had 0.188 GPa peak stress at the fixation center of the arm, and in the center of the joint, and the Avanta design had a 5.20 GPa peak stress at the flexion center. The location and concentration of stresses on the models correspond to literature searches for clinical data, showing that the main failure mechanism for these implants is due to primary flexion-extension natural movement of the joint.展开更多
基金supported by the Natural National Science Foundation of China(NSFC)(61701076)
文摘We present a systematical study on comparison between water and dry coupling in photoacoustic tomography of the humanfinger joints.Compared to the direct water immersion of thefinger for water coupling,the dry coupling is realized through a transparent PDMSfilm-based water bag,which ensures water-free contact with the skin.The results obtained suggest that the dry cou-pling provides image quality comparable to that by water coupling while eliminating the wrin-kling of thefinger joint caused by the water immersion.In addition,the dry coupling offers more stable hemodynamic images than the water coupling as the water immersion of thefinger joint causes reduction in blood vessel size.
文摘This study was undertaken to determine the bending strength properties of off-cut Yellow Meranti wood by applying the finger jointed techniques. The finger orientations that were used in this study are vertical and horizontal finger orientation. Specimens were bonded with PVAc （polyvinyl acetate）. The bending strength properties were determined by the three point and four point bending test method. The results show that vertical finger orientation has the higher mean of modulus of rupture and the modulus of elasticity value of 24.49 MPa （28.91 MPa） and 8,814 MPa （11,668 MPa） respectively. However, the tested specimen properties did not meet the minimum strength of the solid （control） specimens.
文摘Trauma, osteoarthritis and rheumatoid arthritis can destroy the articulating cartilage in small and large joints, especially in the metacarpo [tarso] phalangeal (MCP/MTP) and phalangeal-phalangeal (PIP) joints. Single piece finger prosthetic designs can reduce pain and correct aesthetic issues, with problems on contemporary designs including decreased stability, lack of fixation and loss of functionality. The examined implants are representative models of currently available total joint replacement (TJR) designs for MCP replacement, such as the Swanson one piece implant. These implants have been shown clinically to have a high failure rate (up to 90%), but the cause of failure is unknown. Compressive studies using a 50 N force and medial-lateral loads of 50 N perpendicular to the longitudinal axis of the arms of the implant were individually applied. Due to material failings, lower values had to be used in some cases. Maximum stress values were found for flexion loading;the Swanson approximation had a peak stress of 8.71 GPa at the interface of the joint arm and the flexion center, Neuflex had 0.188 GPa peak stress at the fixation center of the arm, and in the center of the joint, and the Avanta design had a 5.20 GPa peak stress at the flexion center. The location and concentration of stresses on the models correspond to literature searches for clinical data, showing that the main failure mechanism for these implants is due to primary flexion-extension natural movement of the joint.
