Prospective clinical evaluation of a novel anatomic cuff for forearm crutches in patients with osteoarthritis.

The use of forearm crutches has been associated with pain and neuropraxia along the ulnar bone. Whilst anatomic grips have improved comfort of crutch walking, to date anatomic forearm cuffs have not been clinically evaluated. The aim of this clinical pilot study was to determine if the use of forearm crutches with anatomic cuffs reduces pain and increases comfort and function in long-term users of forearm crutches during a 4-week period. Prospective study in ten patients suffering from end-stage osteoarthritis of the lower extremity. All participants were long-term users of conventional forearm crutches. Participants used forearm crutches with an anatomically shaped cuff for 4-weeks. General health was assessed using the SF-36, and the crutches were evaluated using a newly developed questionnaire focusing on symptoms along the forearm. Pain and paresthesia along the forearms decreased by 3.3 points (95% confidence interval difference (CI): [-5.0; -1.6], p = .004) and 3.5 points (95%CI: [-5.1; -1.9], p = .002), respectively, after using the crutches with the new anatomic cuff for 4 weeks. Comfort and sense of security of crutch use increased by 3.0 points (95%CI: [1.3; 4.7], p = .007) and 2.4 points (95%CI: [0.7; 4.1], p = .024). Cross-correlation analysis revealed correlations among items in the same item category and no correlations between items of different item categories of the new questionnaires. An anatomically shaped cuff increases comfort of forearm crutches. Further research should confirm long-term clinical improvement. This study was registered retrospectively in ISRCTN (TRN: ISRCTN 11135150 ) on 14/02/2017

An Integrated Radar Tile for Digital Beamforming X-/Ka-Band Synthetic Aperture Radar Instruments

This paper presents the first experimental assessment of a highly integrated dual-band dual-polarized antenna tile designed for synthetic aperture radar (SAR) digital beamforming (DBF) satellite applications. The demonstrator described in this paper is the first comprehensive experimental validation of an RF module providing the X-band and Ka-band (9.6- and 35.75-GHz) operation with custom downconversion stages. All the antennas, transitions, and downconversion chips are integrated in the same antenna tile fabricated using a customized 15-layer high density interconnect process. The designed tile goes to the limits of the proposed technology and for the high trace density and for the size of the vertical transitions. The proposed results represent the state of the art in terms of compactness for a DBF SAR RF module even though the demonstrator was manufactured with a standard low-cost technology. The experimental assessment proves the validity of the proposed manufacturing and integration approaches showing a substantial agreement between the performance of the individual blocks and of the integrated system

Dual-Band Digital Beamforming Synthetic Aperture Radar for Earth Observation

This paper presents some results of dual-band digital beamforming (DBF) space-borne Synthetic Aperture Radars (SAR). To reduce the cost, size, mass and power consumption of current space-borne SAR systems, a multi-static passive radar concept using DBF, highly integrated analogue and digital circuits and shared-aperture dual-band dual-polarization printed array on printed-circuit-board (PCB) is presented. Such a multi-static SAR system will be employed onboard a constellation of multiple small, low-cost satellites. First, the radar concept is introduced and followed by some results of dual-band shared-aperture antenna arrays. In addition, some results of MMIC and DBF are presented. To verify the simulation results, one prototype C/X dual-band sub-array had been fabricated and measured. The fabrication of X/Ka dual-band SAR system is currently on the way and more experimental results will be presented during the conference

A Ka/X-band digital beamforming synthetic aperture radar for earth observation

A Ka/X-band digital beamforming (DBF) spaceborne Synthetic Aperture Radar (SAR) is presented in this paper. To overcome the performance limitations of current SAR systems while reducing the cost, size, mass and power consumption, it employs a multi-static passive radar concept using DBF, highly integrated analogue and digital circuits and shared-aperture Ka/X band dual-polarization antennas. Compact modular architecture of the proposed system enables the realization of various configurations of spaceborne SAR missions. The radar concept is introduced, followed by some results of antennas, analogue and digital circuits as well as the MMIC technologies