Heinrich Wenz
Heidelberg University
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Featured researches published by Heinrich Wenz.
Computer Methods and Programs in Biomedicine | 2012
Luay Fraiwan; Khaldon Lweesy; Natheer Khasawneh; Heinrich Wenz; Hartmut Dickhaus
In this work, an efficient automated new approach for sleep stage identification based on the new standard of the American academy of sleep medicine (AASM) is presented. The propose approach employs time-frequency analysis and entropy measures for feature extraction from a single electroencephalograph (EEG) channel. Three time-frequency techniques were deployed for the analysis of the EEG signal: Choi-Williams distribution (CWD), continuous wavelet transform (CWT), and Hilbert-Huang Transform (HHT). Polysomnographic recordings from sixteen subjects were used in this study and features were extracted from the time-frequency representation of the EEG signal using Renyis entropy. The classification of the extracted features was done using random forest classifier. The performance of the new approach was tested by evaluating the accuracy and the kappa coefficient for the three time-frequency distributions: CWD, CWT, and HHT. The CWT time-frequency distribution outperformed the other two distributions and showed excellent performance with an accuracy of 0.83 and a kappa coefficient of 0.76.
Respiration | 2014
Ute Oltmanns; Nicolas Kahn; Karin Palmowski; Annette Träger; Heinrich Wenz; Claus Peter Heussel; Philipp A. Schnabel; Michael Puderbach; Matthias Wiebel; Svenja Ehlers-Tenenbaum; Arne Warth; Felix J.F. Herth; Michael Kreuter
Background: Pirfenidone is a novel antifibrotic drug for the treatment of mild-to-moderate idiopathic pulmonary fibrosis (IPF). However, adverse events may offset treatment benefits and compliance. Objectives: To assess recent course of disease, adverse events and compliance in patients who started pirfenidone. Methods: In an observational cohort study, 63 patients with mild-to-moderate IPF who started pirfenidone between May 2011 and June 2013 were reviewed. Pulmonary function, adverse events and treatment compliance were recorded at each clinic visit. Disease progression was defined as a reduction of vital capacity ≥10% and/or diffusion capacity (DLCO) ≥15%. Results: Follow-up time on pirfenidone treatment was 11 (±7) months. Sixty-six percent of the patients continued with pirfenidone monotherapy and 34% of the patients received pirfenidone combined with corticosteroids (CCS) and/or N-acetylcysteine (NAC). There was a nonsignificant reduction in mean decline of percent predicted forced vital capacity after treatment start (0.7 ± 10.9%) compared to the pretreatment period (6.6 ± 6.7%, p = 0.098). Sixty-two percent of the patients had stable disease on pirfenidone treatment. Adverse events affected 85% of the patients, leading to discontinuation of pirfenidone in 20%. Adverse events and treatment discontinuation were seen more frequently in patients with concomitant CCS and/or NAC treatment. Conclusions: Adverse events affect the majority of patients treated with pirfenidone, but are mostly manageable with supportive measures. In this heterogeneous patient group, a nonsignificant effect of pirfenidone treatment on pulmonary function was seen, underlining the need for more data on patient selection criteria and efficacy of pirfenidone, particularly in patients with coexistent emphysema and concomitant NAC/CCS treatment.
Methods of Information in Medicine | 2010
Luay Fraiwan; Khaldon Lweesy; Natheer Khasawneh; Mohammad Fraiwan; Heinrich Wenz; Hartmut Dickhaus
BACKGROUND The process of automatic sleep stage scoring consists of two major parts: feature extraction and classification. Features are normally extracted from the polysomnographic recordings, mainly electroencephalograph (EEG) signals. The EEG is considered a non-stationary signal which increases the complexity of the detection of different waves in it. OBJECTIVES This work presents a new technique for automatic sleep stage scoring based on employing continuous wavelet transform (CWT) and linear discriminant analysis (LDA) using different mother wavelets to detect different waves embedded in the EEG signal. METHODS The use of different mother wavelets increases the ability to detect waves in the EEG signal. The extracted features were formed based on CWT time frequency entropy using three mother wavelets, and the classification was performed using the linear discriminant analysis. Thirty-two data sets from the MIT-BIH database were used to evaluate the performance of the proposed method. RESULTS Features of a single EEG signal were extracted successfully based on the time frequency entropy using the continuous wavelet transform with three mother wavelets. The proposed method has shown to outperform the classification based on a CWT using a single mother wavelet. The accuracy was found to be 0.84, while the kappa coefficient was 0.78. CONCLUSIONS This work has shown that wavelet time frequency entropy provides a powerful tool for feature extraction for the non-stationary EEG signal; the accuracy of the classification procedure improved when using multiple wavelets compared to the use of single wavelet time frequency entropy.
Medizinische Klinik | 2009
Daniela Gompelmann; Heinrich Wenz; Heussel Cp; Felix J.F. Herth
BACKGROUND AND PURPOSE Lung fibrosis as first symptomatic manifestation of microscopic polyangiitis (MPA) is rare. It is characterized by progressive exertional dyspnea, radiologic detection of reticular shadowing, and increased titers of MPA-associated autoantibodies. This case study shall remind of the rare treatable cause of lung fibrosis. CASE REPORT A 78-year-old male patient with long-standing exertional dyspnea and typical chest radiograph appearances of advanced lung fibrosis is presented. The finding of MPA autoantibodies in laboratory tests was decisive to confirm the diagnosis of MPA, and a therapy adapted to the disease severity could be initiated. CONCLUSION An early diagnosis of MPA and a fast onset of therapy are important, because the influence of an already existent lung fibrosis is uncertain.ZusammenfassungHintergrund und Ziel:Eine Lungenfibrose als erste symptomatische Manifestation einer mikroskopischen Polyangiitis (MPA) stellt eine Rarität dar. Sie ist durch eine progrediente Belastungsdyspnoe, einen radiologischen Nachweis einer interstitiellen Zeichnungsvermehrung sowie durch einen laborchemischen Nachweis der für die MPA typischen Autoantikörper gekennzeichnet. Mit diesem Fallbericht soll an die seltene, einer Therapie zugängliche Ursache einer Lungenfibrose erinnert werden.Fallbeschreibung:Berichtet wird über einen 78-jährigen Patienten mit bereits lange bestehender Belastungsdyspnoe bei radiologisch nachgewiesenen charakteristischen Zeichen einer fortgeschrittenen Lungenfibrose. Der Nachweis der für eine MPA typischen Autoantikörper war schließlich zur Diagnosebestätigung ausschlaggebend, und es konnte eine stadiengerechte Therapie eingeleitet werden.Schlussfolgerung:Eine frühzeitige Diagnosestellung einer MPA mit folglich rascher Therapieeinleitung ist wichtig, da die Beeinflussung einer bereits ausgebildeten interstitiellen Lungenerkrankung ungewiss ist.AbstractBackground and Purpose:Lung fibrosis as first symptomatic manifestation of microscopic polyangiitis (MPA) is rare. It is characterized by progressive exertional dyspnea, radiologic detection of reticular shadowing, and increased titers of MPA-associated autoantibodies. This case study shall remind of the rare treatable cause of lung fibrosis.Case Report:A 78-year-old male patient with long-standing exertional dyspnea and typical chest radiograph appearances of advanced lung fibrosis is presented. The finding of MPA autoantibodies in laboratory tests was decisive to confirm the diagnosis of MPA, and a therapy adapted to the disease severity could be initiated.Conclusion:An early diagnosis of MPA and a fast onset of therapy are important, because the influence of an already existent lung fibrosis is uncertain.
Medizinische Klinik | 2009
Daniela Gompelmann; Heinrich Wenz; Claus Peter Heußel; Felix J.F. Herth
BACKGROUND AND PURPOSE Lung fibrosis as first symptomatic manifestation of microscopic polyangiitis (MPA) is rare. It is characterized by progressive exertional dyspnea, radiologic detection of reticular shadowing, and increased titers of MPA-associated autoantibodies. This case study shall remind of the rare treatable cause of lung fibrosis. CASE REPORT A 78-year-old male patient with long-standing exertional dyspnea and typical chest radiograph appearances of advanced lung fibrosis is presented. The finding of MPA autoantibodies in laboratory tests was decisive to confirm the diagnosis of MPA, and a therapy adapted to the disease severity could be initiated. CONCLUSION An early diagnosis of MPA and a fast onset of therapy are important, because the influence of an already existent lung fibrosis is uncertain.ZusammenfassungHintergrund und Ziel:Eine Lungenfibrose als erste symptomatische Manifestation einer mikroskopischen Polyangiitis (MPA) stellt eine Rarität dar. Sie ist durch eine progrediente Belastungsdyspnoe, einen radiologischen Nachweis einer interstitiellen Zeichnungsvermehrung sowie durch einen laborchemischen Nachweis der für die MPA typischen Autoantikörper gekennzeichnet. Mit diesem Fallbericht soll an die seltene, einer Therapie zugängliche Ursache einer Lungenfibrose erinnert werden.Fallbeschreibung:Berichtet wird über einen 78-jährigen Patienten mit bereits lange bestehender Belastungsdyspnoe bei radiologisch nachgewiesenen charakteristischen Zeichen einer fortgeschrittenen Lungenfibrose. Der Nachweis der für eine MPA typischen Autoantikörper war schließlich zur Diagnosebestätigung ausschlaggebend, und es konnte eine stadiengerechte Therapie eingeleitet werden.Schlussfolgerung:Eine frühzeitige Diagnosestellung einer MPA mit folglich rascher Therapieeinleitung ist wichtig, da die Beeinflussung einer bereits ausgebildeten interstitiellen Lungenerkrankung ungewiss ist.AbstractBackground and Purpose:Lung fibrosis as first symptomatic manifestation of microscopic polyangiitis (MPA) is rare. It is characterized by progressive exertional dyspnea, radiologic detection of reticular shadowing, and increased titers of MPA-associated autoantibodies. This case study shall remind of the rare treatable cause of lung fibrosis.Case Report:A 78-year-old male patient with long-standing exertional dyspnea and typical chest radiograph appearances of advanced lung fibrosis is presented. The finding of MPA autoantibodies in laboratory tests was decisive to confirm the diagnosis of MPA, and a therapy adapted to the disease severity could be initiated.Conclusion:An early diagnosis of MPA and a fast onset of therapy are important, because the influence of an already existent lung fibrosis is uncertain.
Medizinische Klinik | 2009
Daniela Gompelmann; Heinrich Wenz; Claus Peter Heußel; Felix J.F. Herth
BACKGROUND AND PURPOSE Lung fibrosis as first symptomatic manifestation of microscopic polyangiitis (MPA) is rare. It is characterized by progressive exertional dyspnea, radiologic detection of reticular shadowing, and increased titers of MPA-associated autoantibodies. This case study shall remind of the rare treatable cause of lung fibrosis. CASE REPORT A 78-year-old male patient with long-standing exertional dyspnea and typical chest radiograph appearances of advanced lung fibrosis is presented. The finding of MPA autoantibodies in laboratory tests was decisive to confirm the diagnosis of MPA, and a therapy adapted to the disease severity could be initiated. CONCLUSION An early diagnosis of MPA and a fast onset of therapy are important, because the influence of an already existent lung fibrosis is uncertain.ZusammenfassungHintergrund und Ziel:Eine Lungenfibrose als erste symptomatische Manifestation einer mikroskopischen Polyangiitis (MPA) stellt eine Rarität dar. Sie ist durch eine progrediente Belastungsdyspnoe, einen radiologischen Nachweis einer interstitiellen Zeichnungsvermehrung sowie durch einen laborchemischen Nachweis der für die MPA typischen Autoantikörper gekennzeichnet. Mit diesem Fallbericht soll an die seltene, einer Therapie zugängliche Ursache einer Lungenfibrose erinnert werden.Fallbeschreibung:Berichtet wird über einen 78-jährigen Patienten mit bereits lange bestehender Belastungsdyspnoe bei radiologisch nachgewiesenen charakteristischen Zeichen einer fortgeschrittenen Lungenfibrose. Der Nachweis der für eine MPA typischen Autoantikörper war schließlich zur Diagnosebestätigung ausschlaggebend, und es konnte eine stadiengerechte Therapie eingeleitet werden.Schlussfolgerung:Eine frühzeitige Diagnosestellung einer MPA mit folglich rascher Therapieeinleitung ist wichtig, da die Beeinflussung einer bereits ausgebildeten interstitiellen Lungenerkrankung ungewiss ist.AbstractBackground and Purpose:Lung fibrosis as first symptomatic manifestation of microscopic polyangiitis (MPA) is rare. It is characterized by progressive exertional dyspnea, radiologic detection of reticular shadowing, and increased titers of MPA-associated autoantibodies. This case study shall remind of the rare treatable cause of lung fibrosis.Case Report:A 78-year-old male patient with long-standing exertional dyspnea and typical chest radiograph appearances of advanced lung fibrosis is presented. The finding of MPA autoantibodies in laboratory tests was decisive to confirm the diagnosis of MPA, and a therapy adapted to the disease severity could be initiated.Conclusion:An early diagnosis of MPA and a fast onset of therapy are important, because the influence of an already existent lung fibrosis is uncertain.
Journal of Medical Systems | 2011
Luay Fraiwan; Khaldon Lweesy; Natheer Khasawneh; Mohammad Fraiwan; Heinrich Wenz; Hartmut Dickhaus
IEEE Engineering in Medicine and Biology Magazine | 2009
Christoph Maier; Vera Rodler; Heinrich Wenz; Hartmut Dickhaus
Methods of Information in Medicine | 2014
Christoph Maier; Heinrich Wenz; Hartmut Dickhaus
European Respiratory Journal | 2013
Ute Oltmanns; Nicolas Kahn; Heinrich Wenz; Claus Peter Heussel; Michael Puderbach; Svenja Ehlers-Tenenbaum; Arne Warth; Felix J.F. Herth; Philip Schnabel; Michael Kreuter