[Studies on the urophonography (2)--Clinical investigation on normal human subjects and patients with benign prostatic hypertrophy].

Recently we have developed an entirely new method of sonic detection of lower urinary tract disorders during micturition. The detection of these sounds was performed by a data catching and recording system, consisting of a detector, amplifier, and recorder. This procedure was designated as "urophonography" and its recording as "urophonogram". Twenty-five patients with BPH before and three months after suprapubic prostatectomy and 10 healthy male volunteers underwent urophonography. The urophonograms were classified into four types. Type 1 was characterized by its diamond shape, while Type 2 was characterized by its random sound spikes. Type 3 was a mixture of Types 1 and 2. Type 4 had only few sound spikes. Analysis of these urophonograms also revealed that the frequencies of these urethral sounds belonged to the range from 0.4 to 1.5 KHz. The amplitude (power) of the sounds was in the range of 40-60 dB. Healthy volunteers belonged to Type 4. BPH patients belonged to Types 1, 2 and 3 at equal frequency. Comparison of uroflowmetric parameters with urophonograms revealed that Type 3 patients with BPH showed a lesser degree of micturition disturbances, which was consistent with the weight of prostatic tumors surgically resected. Urophonography was undertaken before and after the treatment on these patients. It was clearly shown that the pattern of urophonograms shifted to normal (Type 4). It was considered that urophonograms were useful for urodynamic investigation.