Shape Memory Alloys for Use in Medicine

O’Brien, Barry; Bruzzi, Mark

doi:10.1016/b978-0-08-055294-1.00014-3

Cited by 14 publications

(20 citation statements)

References 114 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[2][3][4] NiTi exhibits two unique properties: shape memory effect and superelasticity. 1,5 The shape memory effect is the ability of a material to undergo plastic deformation at a low temperature state (martensite phase), then recovers back to its original undeformed shape when heated above the transformation temperature (austenite phase). The superelasticity occurs when an external stress applied to a material induces a transition to martensite phase and leads to deformation.…”

Section: Introductionmentioning

confidence: 99%

Surface finishing of Nitinol for implantable medical devices: A review

et al. 2022

View full text Add to dashboard Cite

Nitinol (NiTi), a nickel–titanium alloy, has been used for various cardiovascular, orthopedic, fracture fixation, and orthodontic devices. As with most other metallic biomaterials, the corrosion resistance and biocompatibility of NiTi are primarily determined by the properties of the surface oxide layer such as thickness, chemical composition, structure, uniformity, and stability. Currently, a number of finishing methods are used to improve the properties of surface oxide of NiTi with an ultimate goal to produce a defect‐free, impurity‐free, thin homogeneous oxide layer that is stable and composed of only titanium dioxide (TiO2) with negligible amount of Ni species. This review discusses the effects of various surface finishing methods such as mechanical polishing, electropolishing, magnetoelectropolishing, heat treatments at different temperatures, passivation, chemical etching, boiling in water, hydrogen peroxide treatment, and sterilization techniques (steam autoclave, ethylene oxide, dry heat, peracetic acid, and plasma‐based treatments) on the properties of a surface oxide layer and how it impacts the corrosion resistance of NiTi. Considering the findings of the literature review, a checklist has been provided to assist with choosing finishing/sterilization methods and relevant rationale and recommendations to consider when selecting a surface finishing process for NiTi used in implantable medical devices.

show abstract

Section: Introductionmentioning

confidence: 99%

Surface finishing of Nitinol for implantable medical devices: A review

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Surgical wires, to guide catheters or other endovascular devices, typically are inserted at the groin and guided manually to the treatment site in the brain. Current technology for localizing the wire or catheter during insertion involves X-ray fluoroscopy [1] . This repeated illumination during a surgical procedure provides a significant radiation dose to patient and surgeon.…”

Section: Introductionmentioning

confidence: 99%

Ultrasound Localization of Nitinol Wire of Sub-Wavelength Dimension

DeVries

Olafsen

et al. 2022

IEEE Open J. Eng. Med. Biol.

View full text Add to dashboard Cite

To enhance endovascular navigation using surgical guidewires and reduce the use of ionizing radiation, we demonstrate a method for ultrasonic localization of wires with diameters less than the wavelength of ultrasound in the medium. Methods: Nitinol wires with diameters ranging from 50 μm to 250 μm were imaged ultrasonically in a 0.25-in-diameter water-filled tube in a gelatin medium. Imaging frequencies were 5 MHz, 7.5 MHZ, and 10 MHz. Results: For the full range of diameters traversing the phantom, the wires were localized successfully via visual inspection of both regular and difference ultrasound images. Similarly, two convolutional neural networks were trained, and both achieved an accuracy of over 95%. Conclusions: Wires with diameters as small as 50 μm were localized successfully in a water-based gelatin phantom, indicating the potential use of ultrasound to enhance endovascular navigation and surgical treatment.

show abstract

“…The superelasticity in Ni-Ti can recover from about 8-10% strain, before it deforms plastically. This remarkable property along with good damping curves, low stiffness, good corrosion resistance and good biocompatibility (TiO 2 prevents Ni leaching into the human body), enables Ni-Ti to be used in stents, implants, spinal fusion cage, bone plates/screws and other medical applications [7][8][9][10][11][12]. During phase transformations, latent heat is absorbed or released during the shape deformation or recovery.…”

Section: Introductionmentioning

confidence: 99%