Human ECGs corrupted with real CPR artefacts in an animal model: generating a database to evaluate and refine algorithms for eliminating CPR artefacts.

AIM: For the analysis of ECG rhythms during ongoing CPR, single- or two-channel methods have been proposed to eliminate artefacts from the CPR-corrupted ECG. To refine, test and evaluate these algorithms with a realistic data set, we introduce an animal model with which we created an extended database of human ECGs with real CPR artefacts. MATERIAL AND METHODS: In a pig model real CPR-related artefacts were added to annotated human emergency ECGs. Via a special catheter placed in the oesophagus, ECG sequences (duration>10s) were fed in close to the dead pig's heart. The resulting surface potential was recorded on the thorax without and during ongoing chest compressions, which were monitored using a miniature force sensor. RESULTS: The animals served as a vehicle for human ECGs, making it possible to create a database in which 918 real human ECG sequences (437 shockable and 481 non-shockable) were corrupted with CPR-induced artefacts. The achieved signal-to-noise ratios (SNR) ranged from -17 to +15 dB, sensitivity was 93.5% and specificity was 50.51%. The fed-in ECG and the uncorrupted surface ECG correlated almost perfectly (r=0.926+/-0.081; n=918), indicating negligible signal distortion due to the dead pig itself. CONCLUSION: As the generated database includes both the original and the corrupted ECG covering a wide range of SNRs as well as the compression force signal, it provides an extended data set to evaluate the reconstruction performance of CPR artefact-removal algorithms.

Endocrine status in elderly men with lower urinary tract symptoms: correlation of age, hormonal status, and lower urinary tract function. The Prostate Study Group of the Austrian Society of Urology.

OBJECTIVES: To correlate endocrine parameters in elderly men with lower urinary tract symptoms (LUTS) to patient age and clinical parameters such as prostate volume, prostate-specific antigen (PSA) levels, and uroflowmetry and to compare the clinical and endocrinologic parameters in men with or without hypogonadism. METHODS: Men (40 years old or older) with untreated LUTS as defined by an International Prostate Symptom Score (IPSS) of 7 or greater due to benign prostatic hyperplasia were included in this study and underwent the following investigations: IPSS, free uroflow study, postvoid residual volume, transrectal ultrasound for assessment of prostate volume, serum PSA determination, and an endocrine study, including testosterone, human luteinizing hormone, human follicle-stimulating hormone, prolactin, dehydroepiandrostendione-sulphate (DHEA-S), and prolactin. RESULTS: Three hundred twelve men (mean age 62.8 +/- 10.6 years, range 40 to 91) were analyzed. The serum levels of estradiol (correlation coefficient [r] = 0.19), human luteinizing hormone (r = 0.32), human follicle-stimulating hormone (r = 0.19), and DHEA-S (r = -0.39) correlated (P <0.05) with age; no such correlation was seen for testosterone (r = 0.04; P0.05) or prolactin (r = 0.09; P0.05). Estradiol (but not testosterone) correlated (r = 0.17, P = 0.01) with prostate volume. The peak flow rate and PSA did not correlate with any endocrinologic parameter. Hypogonadism (serum testosterone less than 3.0 ng/mL) was detected in 22.1% of patients and had no impact on clinical (IPSS, peak flow rate, prostate volume, and PSA level) or endocrine (human luteinizing hormone, human follicle-stimulating hormone, estradiol, prolactin, and DHEA-S) parameters. CONCLUSIONS: A number of age-related endocrine changes are seen in elderly men with LUTS. Hypogonadism is seen in approximately one fifth of elderly men with LUTS, but in our study it had no impact on symptom status, PSA level, prostate volume, uroflowmetry, or endocrine parameters.