An Acoustic Sensor Based on Active Fiber Fabry-Pérot Microcavities.

We demonstrate an active acoustic sensor based on a high-finesse fiber Fabry-Pérot micro-cavity with a gain medium. The sensor is a compacted device lasing around 1535 nm by external optical pumping. The acoustic pressure acting on the sensor disturbs the emitted laser frequency, which is subsequently transformed to beat signals through a delay-arm interferometer, and directly detected by a photo-detector. In this configuration, the sensing device exhibits a high sensitivity of 2.6 V/Pa and a noise equivalent acoustic signal level of 230 µPa/Hz1/2 at a frequency of 4 kHz. Experimental results provide a wide frequency response from 100 Hz to 18 kHz. As the sensor works at communication wavelength and the output laser can be electrically tuned in the 10 nm range, a multi-sensor network can be easily constructed with the dense wavelength division multiplexing devices. Extra lasers or demodulators are unnecessary thus the proposed sensor is low cost and easy fabrication. The proposed sensor shows broad applications prospect in remote oil and gas leakage exploration, photo-acoustic spectrum detection, and sound source location.

Clinical research on lumbar oblique-pulling manipulation in combination with sling exercise therapy for patients with chronic nonspecific low back pain.

OBJECTIVE: To investigate clinical curative effects of lumbar oblique-pulling manipulation in combination with sling-exercise-therapy training on chronic nonspecific lower back pain. METHODS: A total of 60 patients with chronic nonspecific lower back pain in the Outpatient Department were included in this study. These patients were randomly divided into two groups: the observation group and the control group. The control group adopted a single sling-exercise-therapy training three times a week, while the observation group adopted lumbar oblique-pulling manipulation in combination with manipulation treatment once a week. The course of treatment lasted for four weeks. RESULTS: (1) Before and after treatment, the ODI score was compared within the group. A remarkable statistical significance was observed from the third day (P<0.05). At the third month of follow-up, the difference in ODI scores between these two groups was statistically significant (P<0.05). (2) Before and after treatment, it was observed that differences in VAS scores from the third day were statistically significant (P<0.05). (3) The difference in muscle strength between these two groups had remarkable statistical significance in the third month of follow-up (P<0.05). CONCLUSION: The effective rehabilitation function of lumbar oblique-pulling manipulation in combination with sling-exercise-therapy training in patients with CNLBP is superior to that of sling-exercise-therapy training alone.

Clinical research on lumbar oblique-pulling manipulation in combination with sling exercise therapy for patients with chronic nonspecific low back pain

SUMMARY OBJECTIVE: To investigate clinical curative effects of lumbar oblique-pulling manipulation in combination with sling-exercise-therapy training on chronic nonspecific lower back pain. METHODS: A total of 60 patients with chronic nonspecific lower back pain in the Outpatient Department were included in this study. These patients were randomly divided into two groups: the observation group and the control group. The control group adopted a single sling-exercise-therapy training three times a week, while the observation group adopted lumbar oblique-pulling manipulation in combination with manipulation treatment once a week. The course of treatment lasted for four weeks. RESULTS: (1) Before and after treatment, the ODI score was compared within the group. A remarkable statistical significance was observed from the third day (P<0.05). At the third month of follow-up, the difference in ODI scores between these two groups was statistically significant (P<0.05). (2) Before and after treatment, it was observed that differences in VAS scores from the third day were statistically significant (P<0.05). (3) The difference in muscle strength between these two groups had remarkable statistical significance in the third month of follow-up (P<0.05). CONCLUSION: The effective rehabilitation function of lumbar oblique-pulling manipulation in combination with sling-exercise-therapy training in patients with CNLBP is superior to that of sling-exercise-therapy training alone.

RESUMO OBJETIVO: Investigar os efeitos curativos da manipulação lombar com o movimento de puxar oblíquo combinado a terapia por exercícios de sling-training para dor lombar baixa crônica não específica. METODOLOGIA: Um total de 60 pacientes com dor lombar baixa crônica não específica no ambulatório foram incluídos neste estudo. Esses pacientes foram divididos aleatoriamente em dois grupos: o grupo de observação e o grupo de controle. O grupo de controle aderiu apenas à terapia por exercícios de sling-training três vezes por semana, enquanto o grupo de observação aderiu à manipulação lombar com o movimento de puxar oblíquo combinado à terapia por exercícios de sling-training uma vez por semana. O tratamento durou quatro semanas. RESULTADOS: (1) Antes e após o tratamento, o escore de ODI foi comparado no grupo. Uma significância estatística notável foi observada a partir do terceiro dia (P<0,05). No terceiro mês de acompanhamento, a diferença nos escores de ODI entre os dois grupos foi estatisticamente significante (P<0,05). (2) Antes e após o tratamento, observou-se que diferenças nos escores de VAS a partir do terceiro dia foram estatisticamente significantes (P< 0,05). (3) A diferença de força muscular entre os dois grupos apresentou significância estatística notável no terceiro mês de acompanhamento (p<0,05). CONCLUSÃO: A função de reabilitação efetiva da manipulação lombar com o movimento de puxar oblíquo combinada à terapia por exercícios de sling-training em pacientes com dor lombar baixa crônica não específica é superior à da terapia por exercícios de sling-training sozinha.