Computer-assisted evaluation of the smooth-muscle electromyogram of the corpora cavernosa by fast Fourier transformation

Applications of artificial intelligence in the diagnosis and prediction of erectile dysfunction: a narrative review

Despite the high prevalence of erectile dysfunction, patients are reluctant to seek medical advice, which leads to low diagnostic rates in clinical practice. Artificial intelligence has been widely applied in the diagnosis of many diseases and may alleviate the situation. However, the applications of artificial intelligence in erectile dysfunction have not been reviewed to date. Therefore, the assistance from artificial intelligence needs to be summarized. In this review, 418 publications before January 10, 2021, regarding artificial intelligence applications in diagnosing and predicting erectile dysfunction, were retrieved from five databases, including PubMed, EMBASE, the Cochrane Library, and two Chinese databases (WANFANG and CNKI). In addition, the reference lists of the included studies or relevant reviews were checked to avoid bias. Finally, 30 articles were reviewed to summarize the current status, merits, and limitations of applying artificial intelligence in diagnosing and predicting erectile dysfunction. The results showed that artificial intelligence contributed to developing novel diagnostic questionnaires, equipment, expert systems, classifiers by images and predictive models. However, most of the included studies were not subjected to external validations, resulting in doubt on the generalizability. In the future, more rigorously designed studies with high-quality datasets for erectile dysfunction are required.

Characterization of abdominally acquired uterine electrical signals in humans, using a non-linear analytic method

The present work seeks to determine if a particular non-linear analytic method is effective at quantifying uterine electromyography (EMG) data for estimating the onset of labor. Twenty-seven patients were included, and their uterine EMG was recorded non-invasively for 30 min. The patients were grouped into two sets: G1: labor, N = 14; G2: antepartum, N = 13. G1 patients all delivered spontaneously within 24 h of recording while G2 patients did not. The uterine electrical signals were analyzed offline by first isolating the uterine-specific frequency range and then randomly selecting "bursts" of uterine electrical activity (each associated with a uterine contraction) from every recording. Wavelet transform was subsequently applied to each of the bursts' traces, and then the fractal dimension (FD) of the resulting transformed EMG burst-trace was calculated (Benoit 1.3, Trusoft). Average burst FD was found for each patient. FD means for G1 and G2 were calculated and compared using t test. FD was significantly higher (P < 0.05) for G1: 1.27 +/- 0.03 versus G2: 1.25 +/- 0.02. The wavelet-decomposition-generated fractal dimension can be used to successfully discern between patients who will deliver spontaneously within 24 h and those who will not, and can be useful for the objective classification of antepartum versus labor patients.

Application of correlation techniques in the analysis of corpus cavernosum electromyographic signals

AIM

To establish an objective, easy-to-use and comprehensive method to analyze corpus cavernosum electromyographic signals (CC-potentials).

METHODS

CC-potentials were recorded during flaccidity in 23 young healthy volunteers, with surface electrodes placed on the penile shaft bilaterally. Based on the correlation function of Matlab software, an application program for the analysis of CC-potentials was developed. Individual CC-potentials and their autocorrelation function were evaluated, yielding parameters amplitude (A), duration (D), and dominant frequency (DF). The cross-correlation function of both longitudinal and bilateral pairs of adjacent electrodes was calculated to assess the similarity and mutual delay of CC-potentials recorded simultaneously from different parts of the CC. The parameters derived were squared maximum cross-correlation coefficient (Rmax) and delay (tau). Based on the absolute value of tau and the corresponding inter-electrode distance, propagation velocity (PV) was calculated.

RESULTS

The values of the parameters were determined automatically. No significant difference related to the locations of the electrodes for parameters A, D, and DF was detected. The cross-correlation showed that both longitudinal and bilateral CC-potential pairs had highly similar waveforms (the absolute values of Rmax were 0.80 +/- 0.05 and 0.87 +/- 0.06, respectively). PV of longitudinal pairs was estimated as 6.15 +/- 3.98 cm/s.

CONCLUSION

The application program for correlation analysis of CC-potentials is a comprehensive and versatile method to analyze corpus cavernosum electromyographic recordings. Its objectiveness makes multi-center application possible.

ORIGINAL RESEARCH—ERECTILE DYSFUNCTION: A Reproducibility Study of Corpus Cavernosum Electromyography in Young Healthy Volunteers Under Controlled Conditions

INTRODUCTION

Although the corpus cavernosum electromyography (CC-EMG) has been studied already for 16 years, doubts regarding its reproducibility have remained.

AIM

To assess the reproducibility of CC-EMG under controlled conditions and the influence of confounding factors.

METHODS

Three CC-EMG recording sessions were performed in 13 healthy young men under the same conditions. Furthermore, the effects of potentially confounding factors, such as intake of caffeine, alcohol and smoking, and sexual activity, were investigated in the same population. Using auto- and cross-correlation techniques, CC-potentials were characterized with parameters amplitude (A), duration (D), dominant frequency (DF), maximum cross-correlation coefficient of longitudinal and bilateral CC-potential pairs (Rmax-lon. and Rmax-bi.), and propagation velocity (PV ).

MAIN OUTCOME MEASURES

Comparison of CC-EMG parameters A, D, DF, Rmax-lon., and Rmax-bi. between three recording sessions and assessment of the impact of confounding factors on these parameters.

RESULTS

DF, D, A, and Rmax-lon. showed significant correlations among three sessions; PV showed significant correlations between two sessions performed within the same day but not between those performed on different days; Rmax-bi. did not show significant correlations between any two sessions. Intake of caffeine, alcohol, and smoking did not affect CC-potentials, while the recordings shortly after ejaculation showed more irregular oscillations and less CC-potentials with smaller A.

CONCLUSIONS

CC-potential parameters DF, D, A, and Rmax-lon. have been demonstrated to be reproducible. The results provide a basis for the clinical and scientific application of CC-EMG. CC-potentials are not sensitive to confounding factors such as intake of caffeine, alcohol, and smoking, while measurements shortly after ejaculation should be avoided.

The methodology of corpus cavernosum electromyography revisited

OBJECTIVE

The methodology of corpus cavernosum electromyography (CC-EMG) was revisited, in order to overcome current methodological difficulties that hinder its clinical application.

MATERIALS AND METHODS

Using an 8-channel device, CC-EMG was performed in 12 healthy volunteers. Surface electrodes were placed bilaterally on the penile shaft and the kneecap (reference electrode), the pubis region and the anterior superior iliac spine (ASIS). A band pass filter with cut-off frequencies of 0.1 and 20 Hz was used. At least 2 sessions of recordings were performed in each subject.

RESULTS

Thirty-five of 46 recordings were interpretable. Significant time delays between potentials recorded from different sites of the CC were detected. Clear spatial voltage gradients related to CC-potentials were observed on the pubis region. No voltage changes related to CC-potentials, but electrical activity from other sources were recorded from the ASIS. In contrast to frequency, a clear correlation could be demonstrated between amplitude, duration and polyphasity of CC-potentials recorded in 2 different sessions in the same individual.

CONCLUSIONS

Multichannel monopolar recording of CC-EMG with surface electrodes is practical and has several advantages compared with bipolar recording. The results provide evidence that the recorded signals indeed reflect electrical activity of the CC and therefore offer a basis to pursue further clinical validation studies.

Evaluation of autonomic innervation of the clitoris and bulb

PURPOSE

Female sexual dysfunction is a common disorder but there are few objective measures of female genital function. We present a novel technique to record electrical activity of the female genital erectile tissue.

MATERIALS AND METHOD

We placed concentric needle electrodes in the right clitoral crus and the bulb of 22 healthy women. Following spontaneous activity recording we stimulated the median nerve to activate the sympathetic nervous system. We simultaneously measured evoked activity in the clitoris and bulb, and hand sympathetic skin responses (SSRs).

RESULTS

Spontaneous electrical activity of the clitoris and bulb was present in 13 subjects. A total of 21 subjects had evoked activity in the bulb, while 18 had evoked activity in the clitoris. All subjects had hand SSRs. Evoked genital response latencies were similar to hand SSR latency (p > 0.05). Evoked electrical activity was recordable in the clitoris and bulb but it was more easily performed in the bulb.

CONCLUSIONS

Evoked electrical activity is more consistently obtained than spontaneous activity. These tests represent possible objective measures of female genital autonomic innervation, which may have relevance to female sexual function.

Is dorsale penile vein ligation (dpvl) still a treatment option in veno-occlusive dysfunction?

PURPOSE

To determine the long-term results of the DPVL for the treatment of venous impotence.

PATIENTS AND METHODS

The long term results of DPVL in 134 patients were interviewed. The mean age was 39.2 (range 21-72). Power color doppler imaging, pharmacocavernography/dynamic cavernosometry were performed. Postoperatively, all the patients were controlled in the 6th month, first year and, if possible, once a year. The mean follow-up was 54.8 (14-76) months. Postoperative outcomes were classified into three groups: complete spontaneous erection (CR), response to pharmacotherapy (PR) or no satisfactory improvement (NR).

RESULTS

The short-term success in the 6th month according to above mentioned was 38.8%, 18.6% and 42.5%; and in the first year was 19.4%, 14.9% and 65.6% respectively. The result in 35 patients whose follow-up was at least 5 years (mean 67 months) was 11.4%, 14.3% and 74.3% respectively. Positive prognostic factors were preoperative age <40, duration of erectile dysfunction <2 years, non-smoker patients, non neurogenic disease and distal disease. With all these parameters present, long-term success (CR, PR) rose from 33.6% to 55.9% (P < 0.001).

CONCLUSIONS

Long-term success for unselected patients undergoing DPVL is disappointing; however, careful patient selection significantly improves long-term results.

The value of corpus cavernosum electromyography in erectile dysfunction: current status and future prospect

In the last decade, several investigators have tried to develop corpus cavernosum electromyography (CC-EMG) as a direct clinical method to evaluate the state of the penile autonomic innervation and the cavernous smooth muscle. Both basic and clinical studies have shown promising results. However, its application as a diagnostic tool with clinical relevance was hindered by insufficient knowledge of cavernous smooth muscle electrophysiology, lack of standardization, technical and practical difficulties and problems in the interpretation of the results. Recently, the European Commission created the so-called COST Action B18 (corpus cavernosum EMG in erectile dysfunction), aiming to strengthen the coordination of the European research groups and give the development of CC-EMG a new impetus. This review presents an overview of the physiological background, the current status of CC-EMG, and discusses possibilities for further developments.

Smooth muscle electromyography

This article addresses smooth muscle physiology, electromechanical and pharmacomechanical coupling, computed-based interpretations, and the role of electromyography in the diagnosis of erectile dysfunction.

The role of corpus cavernosum electromyography

Although corpus cavernosum electromyography presents great theoretical appeal as a possible direct clinical measure of penile neurogenic function, it has still not been adopted as a routine diagnostic test in the evaluation of patients with erectile dysfunction. This is because of the considerable technical and interpretative problems associated with the method. This review covers some of the more important research and clinical papers published since its first description in 1989, with a special focus on recent advances in this field.