Pattern of activation of pelvic floor muscles in men differs with verbal instructions.

AIMS: To investigate the effect of instruction on activation of pelvic floor muscles (PFM) in men as quantified by transperineal ultrasound imaging (US) and to validate these measures with invasive EMG recordings. METHODS: Displacement of pelvic floor landmarks on transperineal US, intra-abdominal pressure (IAP) recorded with a nasogastric transducer, and surface EMG of the abdominal muscles and anal sphincter were recorded in 15 healthy men during sub-maximal PFM contractions in response to different verbal instructions: "tighten around the anus," "elevate the bladder," "shorten the penis," and "stop the flow of urine." In three men, fine-wire EMG recordings were made from puborectalis and bulbocavernosus, and trans-urethral EMG recordings from the striated urethral sphincter (SUS). Displacement data were validated by analysis of relationship with invasive EMG. Displacement, IAP, and abdominal/anal EMG were compared between instructions. RESULTS: Displacement of pelvic landmarks correlated with the EMG of the muscles predicted anatomically to affect their locations. Greatest dorsal displacement of the mid-urethra and SUS activity was achieved with the instruction "shorten the penis." Instruction to "elevate the bladder" induced the greatest increase in abdominal EMG and IAP. "Tighten around the anus" induced greatest anal sphincter activity. CONCLUSIONS: The pattern of urethral movement measured from transperineal US is influenced by the instructions used to teach activation of the pelvic floor muscles in men. Efficacy of PFM training may depend on the instructions used to train activation. Instructions that optimize activation of muscles with a potential to increase urethral pressure without increasing abdominal EMG/IAP are likely ideal. Neurourol. Urodynam. 35:457-463, 2016. © 2015 Wiley Periodicals, Inc.

International Continence Society guidelines on urodynamic equipment performance.

These guidelines provide benchmarks for the performance of urodynamic equipment, and have been developed by the International Continence Society to assist purchasing decisions, design requirements, and performance checks. The guidelines suggest ranges of specification for uroflowmetry, volume, pressure, and EMG measurement, along with recommendations for user interfaces and performance tests. Factors affecting measurement relating to the different technologies used are also described. Summary tables of essential and desirable features are included for ease of reference. It is emphasized that these guidelines can only contribute to good urodynamics if equipment is used properly, in accordance with good practice.

Stiffness mapping prostate biopsy samples using a tactile sensor.

Previous studies have demonstrated that the stiffness of cancerous cells reflects their pathological stage and progression rates, with increased cancerous cell stiffness associated with increased aggressiveness. Therefore, the elasticity of the cancerous cells has the potential to be used as an indicator of the cancer's aggressiveness. However, the sensitivity and resolution of current palpation and imaging techniques are not sufficient to detect small cancerous tissues. In previous studies, we developed a tactile-based device to map with high resolution the stiffness of a tissue section. The purpose of this study is to evaluate this device using different tissues (BPH, Cancer and PZ) collected from human prostates. The preliminary results show that the tactile device is sensitive enough to tell the differences of the stiffness of different tissues. The results also disclosed the factors (humidity, temperature and tissue degradation) which could dramatically affect the results of stiffness mapping. The tactile technology described in this paper has the potential to help disclose the underlying mechanical mechanisms that lead to increased stiffness in prostate tumors.

Evaluation of the dynamic responses of female pelvic floor using a novel vaginal probe.

The female pelvic floor (PF) provides anatomical support to many visceral organs, such as uterus, bladder, urethra, vagina, and rectum. Physiologically, the PF is made up of a number of highly coordinated muscle groups organized to respond to postural and abdominal stresses to maintain continence. In this article, we describe a new methodology for the evaluation of PF strength using a novel vaginal probe design, having force and displacement sensors. This design was derived on the basis of imaging data showing that force/displacement characteristics are important determinants of the integrity of the PF function. The prototype probe used was constructed to evaluate the dynamic responses to slow voluntary contractions as well as reflex stress contractions. Initial clinical experiments were performed on nine healthy female subjects. The probe recorded the force and displacement signals on the anterior and posterior sides of the subjects' middle vaginal wall in voluntary PF muscle contraction and cough. The time domain and frequency domain characteristics of the dynamic responses, including the force and displacement responses, of the vaginal wall were measured and the power and energy associated with the dynamic responses of the PF were analyzed showing the differences between the dynamic characteristics of the voluntary PF muscle contraction and cough. Results show that voluntary PF muscle contractions have higher amplitudes, longer duration, and higher power than reflex contractions. The design of this probe enables the measurement of force and displacement during rapidly occurring events.