PubMed Health⌕ Search

PubMed · 10766057

Synframe: a preliminary report.

Abstract

Both endoscopic lumbar spinal surgery and the non-standardized and unstable retractor systems for the lumbar spine presently on the market have disadvantages and limitations in relation to the minimally invasive surgical concept, which have been gradually recognized in the last few years. In an attempt to resolve some of these issues, we have developed a highly versatile retractor system, which allows access to and surgery at the lumbar, thoracic and even cervical spine. This retractor system - Synframe - is based on a ring concept allowing 360 degrees access to a surgical opening in anterior as well as posterior surgery. The ring is concentrically laid over the surgical opening for the approach and is used as a carrier for retractor arms, which are instrumented with either different sizes or types of blades and/or different sizes of Hohmann hooks. In posterior surgery, nerve root retractors can also be installed. This ring also functions as a carrier for fiberoptic illumination devices and different sizes of endoscopes, used to transmit the surgical procedure out of the depth of the surgical exposure for both teaching purposes and for the surgical team when it has no longer direct visual access to the procedure. The ring is stable, being fixed onto the operating table, allowing precise minimally open approaches and surgical procedures under direct vision with optimal illumination. This ring system also opens perspectives for an integrated minimally open surgical concept, where the ring may be used as a reference platform in computer-navigated surgery.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M Aebi, T Steffen. 2000. Synframe: a preliminary report.. https://doi.org/10.1007/pl00010021

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Challenges of short magnet design.

The desire to improve patient comfort and acceptance of high field magnetic resonance imaging (MRI) systems results in new approaches to magnet and other critical MRI component design. One such approach, based upon an anatomical field of view analysis, is presented in this paper. The approach is utilized to define imaging volume requirements for short, high field, solenoid magnet designs that maintain whole body imaging capability. A short magnet design with excellent magnetic field homogeneity is presented accordingly. Combined with a novel flared gradient coil the overall system achieves improvements in openness.

Equipment Design↗

An application of permeable reactive barrier technology to petroleum hydrocarbon contaminated groundwater.

A funnel and gate permeable reactive barrier was designed and built to treat groundwater contaminated with dissolved phase toluene. ethyl benzene. and xylene and n-alkanes in the C6-C36 fraction range. Removal efficienicies for the funnel and gate system varied from 63% to 96% for the monocyclic aromatic hydrocarbons. Average removal efficiencies for C6-C9, C10-C14, and C15-C28 fraction ranges were 69.2%, 77.6% and 79.5%. respectively. The lowest average removal efficiencies were 54% for the C29-C36 n-alkane fraction. The overall average removal efficiency for the funnel and gate system towards petroleum hydrocarbons present in the groundwater was 72% during the 10 month period over which the data were collected, and has allowed relevant water quality objectives to be met.

Equipment Design↗

Ex vivo testing of a temperature- and pressure-controlled amnio-irrigator for fetoscopic surgery.

BACKGROUND: Currently, amnioinfusion fluids used in operative fetoscopy usually are preheated to body temperature. As the complexity of procedures increases, purposed designed devices should be designed that allow control of pressure and temperature during amnioinfusion or amnioexchange. In the current study, a prototype amnio-irrigator and fluid heater were evaluated. METHODS: The medical fluid heater heats fluid by conduction up to 37 degrees C. The maximum irrigation pressure and flow rates can be preset. Actual irrigation pressure (0 to 30 mm Hg) and flow rate (0 to 300 mL/min) can be read on the front panel. A series of ex vivo experiments were set up to determine the relationship between the flow rate (FR) and lumen of the instruments as well as the maximum flow rate (MFR) with and without the pressure control. Further, the relationship between FR and the irrigation pressure (IP) was determined. In an artificial pseudoamniotic sac the relationship between FR and change in temperature was measured, with and without the use of the medical fluid heater. RESULTS: When the IP was limited to 24 mm Hg, FR and pressure were correlated (r = 0.34; P <.001). The larger the functional lumen of the fetoscopic instrumentation, the higher the flow (r = 0.43; P <.001) and the lower the increase in IP (r = -0.47; P <.001). A quadratic relation between flow and temperature was observed both for preheated fluid as when using the fluid heater (r(2) = 0.71 and r(2) = 0.88; P <.001). However, at low flow rates, a thermal decrease of over 3 degrees C was observed when the fluid heater was not used. CONCLUSIONS: The current study quantifies an expected relationship between the diameter of the irrigation channel and achievable flow rates. It also shows that a medical fluid heater is needed when strict control of temperature would be desired.

Equipment Design↗