Principles of Joint Prostheses
Verna Wright, Eric L. Radin in Mechanics of Human Joints, 2020
The polyethylene to polished metal articulation transmits load from one component to the other. The components must be firmly attached to the host skeletal system to transmit the loads associated with activity. Early in the experience of joint replacement, attachment by “carpentry” with screws, bolts, or wedging an implant was the norm. These implants sometimes became loose and caused patients pain (29,36). Charnley introduced self-curing acrylic resin, polymethyl methacrylate (PMMA), to joint replacement by using this material as grouting to hold arthroplasty components in place. PMMA is also commonly known as Lucite or plexiglass and has been used extensively in dentistry. [The material Charnleyinitially used was obtained from a dental supply house and colored red for use in dentures (37).]
Methods of Evaluation in Orthopaedic Animal Research
Yuehuei H. An, Richard J. Friedman in Animal Models in Orthopaedic Research, 2020
‘Sawing-grinding” is the traditional method used with plastic embedded specimens. The specimen is sectioned with a diamond-coated wafering saw (such as the Buehler Isomet 2000, Struers Accutome-5, or Leco VC-50) into 0.2-1.0 mm thick slices. The slices are then glued onto a Plexiglass slide and ground on a grinding machine (such as the Buehler Ecomet 3, Struers Dap-V, or Leco VP-160) to produce 30-100 pm thick sections. In patient and skilled hands, the thickness of the ground sections can be less than 15 pm.29 Well controlled systems with automatic grinding capacity, such as the Exakt sawing-grinding system (Exakt Apparatebau, Germany),30 are also available but are costly. The process is tedious and time consuming. Also, because the slices made before grinding are relatively thick, for small specimens successful cuts have to be guaranteed for production of useful sections for evaluation without wasting.
Case studies (2006–2020)
Stephen Verderber, Ben J. Refuerzo in Innovations in Hospice Architecture, 2019
The sloping site provides impetus to split the parti into two intersecting elements and step the composition at the uppermost levels – resulting in the roof terrace on the entire west wing. The terrace features vegetation, benches for patients, staff and visitors, trellises, and waist-height lighting, together establishing human scale and wayfinding aids. The perimeter of this terrace is protected by transparent Plexiglas panels approximately ten feet in height. The paving surface is wood decking and slate tiles. The dining and dayroom on the residential floor has a vertical wall partition that allows see-through connections. Furnishings in the dayroom are informal and positioned in clusters, allowing for reconfiguration as occupants’ needs dictate. Patients are encouraged to spend time here and on the roof terrace as physical and psycho-emotive conditions allow. A transparent grid-wall is also utilized at the staff workstation on the residential unit. Each bedroom features wood paneled headwall (with required medical gas and electrical outlets), laminate wood flooring, full-height operable windows, mechanical patient lift, and a panel separating the sleeping zone from adjoining bath/shower (Figures 6.1.6 to 6.1.9a–b).
Resumption of pulmonary function testing during the COVID-19 pandemic
Published in Canadian Journal of Respiratory, Critical Care, and Sleep Medicine, 2022
Sanja Stanojevic, François Beaucage, Vikram Comondore, Marie Faughnan, Tom Kovesi, Carolyn McCoy, Colm McParland, David Pawluski, Farzad Refahi, Jeremy Road, Micah Kooperberg
The ventilation efficiency within each facility should be used to determine adequate time between tests.22,23 Laboratories should have the AER measured by building engineering or can use portable CO2 monitors to provide an estimate of ventilation efficiency.24–26 The tables provided by the CDC for both AER and ambient CO2 can be used as a guide to determine local policies.25 Physical distance between the technician and patient should be maintained as much as possible. Many institutions and businesses have installed plexiglass to provide a physical barrier between individuals. This barrier primarily helps to prevent transmission from droplets; however, given the increased risk of aerosol transmission, plexiglass barriers may be insufficient to prevent transmission and may actually impair effective room ventilation. Previous safeguards such as the use of disposable bacterial/viral filters to prevent inter-patient transmission must continue to be employed.27
Student perceived impact of a physical, kinetic and interactive model
Published in Journal of Visual Communication in Medicine, 2019
Erica Reneé Malone, Glenda Bingham, Jinsil Hwaryoung Seo, Michelle D. Pine
Considering that the model would be used in the gross anatomy lab alongside many different chemicals, it was important that the stand was not able to absorb and emit the odour from these chemicals. The stand also had to be easy to clean, provide stability and provide enough space for interaction and demonstration of movement. The base of the structure, created to support this model, was constructed from a half-inch (1.27 cm) thick piece of clear plexiglass cut into a 24 inch by 24 inch (60.96 cm by 60.96 cm) square. The limb support stand was constructed with one-inch (2.54 cm) thick acrylic plexiglass sheets cut into varying sizes: one vertical support stand at 3 feet (91.44 cm) tall and 2 inches (5.08 cm) wide and one circular arm with an outer diameter of 8 inches (20.32 cm) and an inner diameter of 7 inches (17.78 cm). The stand was painted with black acrylic paint and sealed with glossy water-based finish. The combination of a non-porous material (plexiglass) and the paint with the finish addresses concerns about chemicals being absorbed into the material and assures ease of cleaning. The limb model was attached to the vertical supporting stand at two points along the border of the scapula using 5/16″ (0.794 cm) square Power Take-Off (PTO) pins and wooden spacers. Small magnets were placed on the distal-most point of the limb model and the base of the model stand to weigh-down the distal limb and allow it to return to the proper neutral position. The magnets were fixed to the fourth distal phalanx and the base of the model stand with epoxy (Figure 1).
Vaginal film for prevention of HIV: using visual and tactile evaluations among potential users to inform product design
Published in Pharmaceutical Development and Technology, 2018
K. M. Guthrie, L. Rohan, R. K. Rosen, S. E. Vargas, J. G. Shaw, D. Katz, E. M. Kojic, A. S. Ham, D. Friend, K. W. Buckheit, R. W. Buckheit
Participants were asked to evaluate prototype films across three specific attributes: size, texture and color. Each attribute was presented on separate, specially fabricated trays, with film prototypes distributed between two sheets of clear Plexiglas®. Tray-1 held four sizes of film: 1″×1″; 1″×2″; 1″×3″ and 2″×2″. Tray-2 held three different film textures: both surfaces smooth, both surfaces textured, one surface smooth/one textured. Tray-3 held three different film colors: clear, translucent and opaque (Figure 1). Participants completed a qualitative in-depth film preference interview in which they first considered the attributes separately, then combined characteristics, ultimately considering which combinations might optimize film design and use. Interviews lasted 20–50 min, were audio-recorded and transcribed verbatim for analysis.
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