1977 Volume 68 Issue 4 Pages 337-362
Using a 6-channel polygraph, the age- and sex-bound difference of the mechanism of urination in normal children was studied through simultaneous measurement of the intra-vesical pressure, intraurethral pressure, intra-abdominal pressure, tone of the anal sphincter, EMG recording of the anal sphincter, and urinary flow rate.
As the results of examination on the apparatus and method of measurement (Fig. 1), instrument for measurement (Fig. 2-1, 2, Fig. 3-1, 2), errors in measurement and method of correction (Fig. 4, Fig. 5-1, 2, 3, 4, Fig. 6-1, 2), the author was convinced of the sufficient feasibility of measurement by this method.
Based on the wave patterns on urination of 6 factors of urination obtained by the methods described above, 35 parameters of urination were determined. These consisted of 25 parameters directly obtained by the measurement and 14 complex parameters obtained by synthesis of the former parameters (Fig. 7-1, 2).
In 98 normal children, 43 boys and 55 girls (Table 1), these parameters were measured and statistically analyzed by student's t-test (Table 2-3). The purpose of this treatment consists of (1) establishment of normal criteria in the hydrodynamic tests of urinary flow in obstructive diseases of the lower urinary tract and (2) evaluation of the degree of completion of the mechanism of urination with advancing age and the functional difference of the lower urinary tract between males and females.
The following conclusions were drawn.
1) Results of measurement of these parameters in normal children of various ages are shown in Tables 2 and 3.
2) Pelvic floor (striated musculature) appears to develop regardless of the sex difference (Table 4).
3) Contraction or process of contraction of the detrusor muscle appears to be constant since birth regardless of age and sex (Table 4).
4) Regardless of the age, parameters with male to female difference appear to reflect the anatomical and functional differences of the lower urinary tract between males and females.
The following results were obtained from the analysis of wave patterns on urination of 6 factors of urination (Fig. 7-Fig. 10).
1) A mild rise is noted in the wave pattern of the intra-abdominal pressure during the period of urination in girls but none at all in boys.
2) The wave pattern of the intra-urethral pressure suddenly rises after the urinary inflow into the urethra, followed by a monophasic or occasionally biphasic smooth parabolic pattern.
3) After a mild rise 2-3 seconds prior to urination, the wave pattern of the intra-vesical pressure rapidly rises simultaneously with the opening of the bladder neck, with the height somewhat larger than the wave pattern of the intra-urethral pressure.
4) The wave pattern of the tone of the anal sphincter starts to fall 3 seconds prior to the beginning of urination. The low value persisted throughout the period of urination, followed by a rise soon after the end of urination.
5) The EMG of the anal sphincter is similar to the wave pattern of the tone of the anal sphincter. Electrically silent state is seen from before urination and persisted for some time after urination, followed by increases in amplitude and discharge frequency.
6) The wave pattern of the urinary flow rate assumes a smooth bell-like shape.
The following wave patterns were demonstrated under special conditions.
1) Cases with pain in urination (Fig. 11-1, 2, 3).
2) Cases with maximum restraint on urination (Fig. 12).
3) Wave patterns on voluntary interruption of urination (Fig. 13).
4) Wave patterns on efforts of urination with empty bladder (Fig. 14).
5) EMG recorded separately from the right and left side in order to evaluate the attitude of contraction of the right and left anal sphincters (Fig. 15).
Studies were also made on the difference of EMG wave patterns between the surface electrode and needle electrode method (Fig. 16), the role of the pelvic floor during the peri
