Extracting and analyzing rabbit somatosensory evoked potential on the basis of continuous wavelet transform and multi-resolution analysis / 生物医学工程学杂志

This study was directed at extracting the rabbit somatosensory evoked potential (SEP), locating and analyzing the waveform of rabbit SEP. The rabbit was narcotized and stimulated by 0.5 Hz electric pulse. Potential of scalp was sampled at 3.764 Hz. Rabbit somatosensory evoked potential was extracted by one-dimension multi-resolution analysis, and continuous wavelet transform (CWT) was employed to locate and analyze the wave of SEP. The study results showed that Single-trail SEP can be extracted by Daubechies wavelet, when wavelet transform result of single-trail was compared with the result of averaged SEP. Wave component of SEP can be located precisely through the method of continuous wavelet transform. Frequency feature of SEP can also be analyzed by CWT. The technique of continuous wavelet transform, which can project a one-dimension signal into a two-dimension time-frequency space, shows good application prospect of processing medical electronic signal.

Clinical analysis of rectal cancer in patients younger than 40 years old / 中国普通外科杂志

Objective To investigate the clinicopathological characteristics,treatment methods and prognosis of rectal cancer in patients younger than 40 years old.Methods From Jan,1998 to Dec,2003,325 treated rectal cancer patients with complete surgical records were divided into two groups:young patients group(younger than 40 years old)49 patients,accounted for 15.1%;middle and old patients group(older than 40years old)276 patients,accounted for 84.9%.The clinicopathological characteristics,treatment methods and follow-up data were compared.Results Among the younger patients,cancer in middle and lower segments of rectum accouned for 79.6%(39/49),infiltrative cancer accounted for 55.1%(27/49),mucous and low-differentiated cancer accounted for 83.7%(41/49),cancer invasion of serosa occurred in 87.8%(43/49),lymph node metastasis in 75.5%(37/49),Miles operation was performed in 65.3%(32/49)and Dixon operation in 34.7%(17/49).These characteristics differewed significantly from middle-aged and old patients.And the 5-year survival-rate in youn patient group was 32.7% and in middle and old patient proup was 60.9% respectively,(P