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Short-use products: packaging, consumables and disposables
Published in Jane Penty, Product Design and Sustainability, 2019
The design of the menstrual cup stands out as an example of using lateral rethinking to address important social and environmental issues by going to the source of the problem. Menstrual cups first appeared in the 1930s but the ‘Tasette’ which was marketed in the 1960s failed commercially against disposables which were being heavily pushed. With environmental concerns growing, it reappeared in a latex version, ‘the Keeper’, in 1987 in the USA. Finally, in 2002, the first hypoallergenic medical-grade silicone menstrual cup, the Mooncup®, was developed in the UK, and since then many design variations have been produced around the world (fig 5.15). Although it is by no means a solution for all women, there are many for whom it offers a viable alternative to disposables.
Adjustable intraocular lenses: The light adjustable lens
Published in Pablo Artal, Handbook of Visual Optics, 2017
Calhoun Vision has developed a silicone IOL that allows for noninvasive power adjustment postimplantation. Calhoun Vision’s light adjustable lens (LAL) is based on the inclusion of a proprietary photoreactive silicone macromer and photoinitiator within a medical grade silicone polymer matrix. Postoperative in situ irradiation of the implanted Calhoun Vision LAL using the light delivery device to deliver targeted dosages of UV light (365 nm) produces modifications in the lens curvature resulting in predictable spherical, cylindrical, and aspheric changes.
Industrial Polymers
Published in Manas Chanda, Plastics Technology Handbook, 2017
Commercial IPNs have been developed to combine useful properties of two or more polymer systems. For example, high levels of silicone have been combined with the thermoplastic elastomer (TPE) based on Shells Kraton styrene–ethylene/butadiene–styrene TPE and Monsantos Santoprene olefin TPE. These IPN TPEs are said to provide the biocompatibility and release properties of silicone with tear and tensile strength up to five times greater than medical-grade silicone. Thermal and electronic properties and elastic recovery are also improved.
Active esophageal cooling during radiofrequency ablation of the left atrium: data review and update
Published in Expert Review of Medical Devices, 2022
Julie Cooper, Christopher Joseph, Jason Zagrodzky, Christopher Woods, Mark Metzl, Robert W. Turer, Samuel A. McDonald, Erik Kulstad, James Daniels
In contrast, active esophageal cooling has shown benefit in several studies, including two randomized controlled pilot studies [13,14] and one large randomized controlled trial (RCT) [15]. The largest trial demonstrated an 83% reduction of endoscopically detected esophageal lesions. An esophageal cooling device (ensoETM, Attune Medical, Chicago, IL) developed for patient temperature management became available commercially in Europe in 2014 and in the United States in 2015 [16,17]. The device is a multi-lumen medical-grade silicone tube (Figure 1) with channels to allow the flow of water provided by an external heat exchanger. Adjustment of water temperature on the external heat exchanger allows continuous cooling of the esophagus. During RF ablation, a temperature of 4°C is typically used [18]. The device has been used in laser ablation with a similar setpoint temperature, but analysis of efficacy is pending. To date, no known use has occurred with either hot balloon ablation, where atrioesophageal fistula is known to occur [19], or in pulsed field ablation, where thermal injury may be less common, but is likely dependent on specific settings [20,21]. Active cooling using different configurations has been evaluated as a thermal mitigation strategy with pulsed field ablation primarily in oncology applications [22]. On the other hand, the use of the device has been evaluated for warming against cryothermal energy during cryoablation, with results from a pilot study not showing benefit (presumed due to the device temperature maximum of only 42°C that can safely be used) [23].
Haemodialysis catheters – a review of design and function
Published in Expert Review of Medical Devices, 2022
HD catheters are generally manufactured from semi-rigid polymer materials such as polyurethane or polyvinyl, or from soft flexible polymers like silicone-plastic or medical-grade silicone. Firm catheters are easier to insert percutaneously, are resistant to kinking, and may be of smaller gauge because of the ability to manufacture the device with thinner walls and hence a relatively large inner lumen. The drawback of such stiffness, however, is greater mechanical trauma. Inflexible polymers of prototypical catheters were superseded by pliable silicone rubber and silicone plastic because they are less traumatizing and less thrombogenic [3], and therefore better-suited for long-term use. Currently, most catheter products are again composed of polyurethane; modern polyurethane substances, such as polyurethane carbonate, are thermosensitive, meaning they soften with increased temperature after insertion, and are more biocompatible [11].
Profile of the Jada® System: the vacuum-induced hemorrhage control device for treating abnormal postpartum uterine bleeding and postpartum hemorrhage
Published in Expert Review of Medical Devices, 2021
Mary D’Alton, Kara Rood, Hyagriv Simhan, Dena Goffman
The Jada System is an intrauterine device that utilizes low-level vacuum (i.e. 80 mm Hg ± 10 mm Hg) to encourage the natural forces of uterine contraction to control abnormal postpartum uterine bleeding or PPH after childbirth. The VHC device is made of soft medical-grade silicone and consists of an elliptical intrauterine loop on the distal end of a tube. The intrauterine loop is lined with 20 vacuum pores that are 4 mm in diameter, oriented inward along the loop. A soft shield covers the outside of the loop to protect uterine tissue from the vacuum and is designed to prevent occlusion of the pores located on the inner surface of the loop. These pores enable the application of vacuum to collapse the uterus and evacuate any pooled blood from within the uterus. Between the intrauterine loop and the tube is the cervical seal, which limits vacuum to only the uterine cavity when placed at the external cervical os and filled with sterile fluid. The proximal end of the device tube connects to sterile vacuum tubing with an inline canister and a regulated vacuum source (typically wall suction or a transportable regulated vacuum source; see Figure 1).