Effect of Rayleigh Wave on Ultrasonic Underground Imaging

AbstractIn order to acquire image with higher resolution and less error for detecting underground objects, a three dimensional ultrasonic underground imaging technique using an electromagnetic-induction type sound source and an amplitude correlation synthesis processing (ACSP) method has been proposed in our previous work. Depending on the conditions of the ground surface, Rayleigh waves propagating along the surface directly may be received with significant amplitude by the receiver array. That will cause interference with the reflect signal of the underground objects and will bring forth error images to the imaging result. In this paper, the Rayleigh wave with comparatively high amplitude is measured experimentally in a model field filled with mountain sands, and its waveform is estimated and simulated approximately by an exponentially decaying sinusoidal wave. The effect on the image of underground object is discussed by synthesizing the received signal with the modeled Rayleigh wave with various relative amplitudes. The result images calculated by ACSP method show that the effect of Rayleigh wave is not marked when its peak amplitude is not greater than that of the signal reflected from the underground object

Subcutaneous Achilles tendon rupture in an eighty-year-old female with an absence of risk factors

Achilles tendon ruptures rarely occur in patients over 80 years of age. However, it is unclear what treatment, surgical or conservative, is suitable for such an Achilles tendon rupture in the elderly. In addition, the clinical results of an Achilles tendon rupture in the elderly are disappointing. We report here the case of a subcutaneous Achilles tendon rupture in an eighty-year-old, healthy female, who returned to her previous level of activity following surgical treatment. Additional case reports of other instances of successful treatment are needed to help establish the optimal treatment protocol for an Achilles tendon rupture in the elderly

The Subtalar Arthroscopic Findings After Osteosynthesis for Calcaneal Fractures

Category: Arthroscopy Introduction/Purpose: A Sanders type II-IV calcaneal fracture is an intrarticular fracture of the subtalar joint, which may shift to traumatic osteoarthritis. We therefore perform open reduction and plate fixation in order to obtain a good reduction in such fractures. The purpose of this study was to evaluate the effectiveness of the subtalar arthroscopy after osteosynthesis for calcaneal fractures. Methods: We performed subtalar arthroscopy in fifteen patients (male, n=12; female, n=3; mean age, 54.9) between September 2010 and April 2014 who had some complaints at the time of plate removal after the treatment of calcaneal fractures. The mean follow-up period was 9.1 months. The Sanders classifications were as follows: Type I (n=1), Type II (n=5), Type III (n=7) and Type IV (n=1). All of the cases had bone union. There was no cases of reduction failure. Observation and joint synovectomy was performed during subtalar arthroscopy, which was performed under lumbar anesthesia. Plate removal was performed after the completion of subtalar arthroscopy. Results: The average AOFAS score improved from 82 points preoperatively to 94 points postoperatively. There were no complications. The formation of intra-articular fibrous tissues and adhesion of the subtalar joint were observed during arthroscopy in all cases; traumatic articular cartilage injuries were found in 10 cases (67%); and synovitis around peroneal tendon was found in 13 cases (87%). Pain and displeasure improved after the resection of fibrous tissues and synovectomy. Conclusion: A patient who had an articular cartilage injury complained of low-level pain. Subtalar arthroscopy is a valuable tool after calcaneal fractures

Subcutaneous Achilles tendon

rupture in an eighty-year-old female with an absence of risk factor