Breath Measurement Method for Synchronized Reproduction of Biological Tones in an Augmented Reality Auscultation Training System.

An educational augmented reality auscultation system (EARS) is proposed to enhance the reality of auscultation training using a simulated patient. The conventional EARS cannot accurately reproduce breath sounds according to the breathing of a simulated patient because the system instructs the breathing rhythm. In this study, we propose breath measurement methods that can be integrated into the chest piece of a stethoscope. We investigate methods using the thoracic variations and frequency characteristics of breath sounds. An accelerometer, a magnetic sensor, a gyro sensor, a pressure sensor, and a microphone were selected as the sensors. For measurement with the magnetic sensor, we proposed a method by detecting the breathing waveform in terms of changes in the magnetic field accompanying the surface deformation of the stethoscope based on thoracic variations using a magnet. During breath sound measurement, the frequency spectra of the breath sounds acquired by the built-in microphone were calculated. The breathing waveforms were obtained from the difference in characteristics between the breath sounds during exhalation and inhalation. The result showed the average value of the correlation coefficient with the reference value reached 0.45, indicating the effectiveness of this method as a breath measurement method. And the evaluations suggest more accurate breathing waveforms can be obtained by selecting the measurement method according to breathing method and measurement point.

Two-Stage Complete Deroofing Fistulotomy Approach for Horseshoe Fistula: Successful Surgery Leaving Continence Intact.

PURPOSE: Surgery of the horseshoe fistula is challenging due to its complex configuration and sphincter muscle involvement. Complete deroofing fistulotomy for horseshoe fistula is highly curative with the eradication of all fistulous lesions but has been discredited for its high incontinence rate. It was replaced with the more conservative Hanley's procedure leaving the lateral tracts intact, despite its issue of recurrence. Our study aimed to report the outcomes of a procedure dividing complete deroofing fistulotomy for horseshoe fistula into 2 stages to avoid impairment of sphincter function. METHODS: We retrospectively reviewed 139 patients who underwent surgery for horseshoe fistula using the 2-stage complete deroofing fistulotomy method between 2014 and 2017. The first surgery deroofed the lateral tracts with an arch-like incision severing the anococcygeal ligament. The primary lesion was also drained and curetted. A seton was placed in the primary tract which was laid open in the second surgery after the lateral wound had partially healed. RESULTS: Recurrence was observed in 12 patients. All were superficial recurrences except for 1, in which recurrence was confirmed in the primary lesion. Those with blind intersphincteric upward extensions had a significantly higher recurrence rate. Furthermore, patients who resided far from the hospital and could not make visits for frequent wound inspections also had a significantly higher recurrence rate. No patient had any continence issues at the end of the follow-up period. CONCLUSION: Managing horseshoe fistula with the 2-stage deroofing fistulotomy approach allows for eradication of the fistula tract without compromising anal sphincter function.