RESUMEN
This paper proposes a novel design of an optical system for depth measurement, adopting a computer-generated hologram to project a periodic line pattern from which a coaxial triangulation is performed. The spatial periodicity of diffraction images captured in the system is converted to the frequency domain, and the relative depth of the plane of interest is acquired. The experimental results show that the system could achieve resolution in the range of 1 mm over a relative depth range of â¼300-600 mm from the camera. The standard deviations are 0.71 and 0.46 mm for two experiments.
RESUMEN
OBJECTIVE: The aim of this study was to investigate the effectiveness of device-assisted ultrasound-guided steroid injection for treating plantar fasciitis. DESIGN: An ultrasound-guided injection device designed with space for securing a transducer and syringe was used to guide steroid injection. Patients with unilateral plantar fasciitis were enrolled and randomly divided into device-assisted ultrasound-guided and palpation-guided groups. Pain intensity was measured using a visual analog scale and tenderness threshold. Ultrasound and pain intensity evaluations were performed before injection and at 3 wks and at 3 mos postinjection. Betamethasone (7 mg) and 1% lidocaine (0.5 ml) were injected into the inflamed plantar fascia. RESULTS: Thirty-three patients who received either device-assisted ultrasound-guided or palpation-guided injection had significantly lower visual analog scale scores (P < 0.001) and higher tenderness threshold (P < 0.01) postinjection. However, the device-assisted group had higher tenderness threshold (9.02 ± 1.38 vs. 7.18 ± 2.11 kg/cm; P = 0.007), lower visual analog scale score (1.88 ± 2.13 vs. 3.63 ± 2.60; P = 0.046), and lower hypoechogenicity incidence in the plantar fascia (3/16 vs. 9/16; P = 0.033) than the palpation-guided group did at 3 mos postinjection. The heel pad was significantly thin (P = 0.004) in the palpation-guided group postinjection. CONCLUSIONS: Device-assisted ultrasound-guided injection for treating plantar fasciitis results in better therapeutic outcomes than palpation-guided injection does.
