Computer aided tool for diagnosis of ENT pathologies using digital signal processing of speech and stroboscopic images (1).pdf
RESEARCH Open Access Computer aided tool for diagnosis of ENT pathologies using digital signal processing of speech and stroboscopic images Amaia Méndez Zorrilla1*, Begoña García Zapirain1 and Agustín Pérez Izquierdo2 Abstract The development of computer software and other technologies greatly facilitates the evaluation of pathological voice patients. This fact allows to reduce exploration time, improves the reproducibility of results and creates the possibility of test protocol standardization needed for the intercommunication between the different voice specialists. The proposed application encompasses the most important aspects which should be taken into account regarding dysphonic patients. It is a multidimensional scope which involves subjective questionnaires and perceptual, aerodynamic, acoustic and stroboscopic evaluations. In this system, the authors have designed and created simple tools for recording and automatic acoustic analysis for the acquisition and edition of stroboscopic images. The purpose is to work with all necessary tools running on a single application, without having to export and import data from other computer programs. Therefore, the objective is to synthetize the basic voice and the exploration of the vocal folds, simplifying it through the design of a program which helps us to analyze step-by -step each aspect of the vocal pathology. The evaluation of the tool has been performed by the otolaryngologists through periodical (medical) appointments on 25 patients for one year a year, and the results are promising either for the professionals as well as for the patients which receive a detailed report with the objective information concerning the features of their voice and vocal cords. Keywords: Vocal pathologies, Otolaryngologist, Software application, Objective parameters, Diagnosis Introduction Considering the number of people suffering voice path- ologies: between 3% and 9% in USA (Nerrière et al. 2009), and 5% in Spain (SEORL, SEORL. http://www. seorl.net/. Accessed 26 August 2012), it is clear that these kinds of problems affect a very high percentage of the population. This is the reason why the authors be- lieve that the study and development of techniques for the detection of vocal pathologies is important. The advances in the area of diagnosis of otorhino- laryngology and speech therapy have been focusing in improving image acquisition devices, aimed at the obser- vation of vocal folds and their functioning. Initially the ENT (Ear-Nose and Throat) specialist used a laryngeal mirror and performed the evaluation and diagnosis based on the information they could obtain with this de- vice. Today we have other techniques for the acquisition and recording of images, which allow a posteriori evalu- ation, being Videolaryngostroboscopy (VLS) and Digital High-Speed videoendoscopy (HSV) the main ones. It is important that the specialist knows the limitations the techniques used present, as VLS is only capable of capturing images at the speed of 25–30 frames/s (Lee et al. 2001). These limitations affect mainly to the diag- nosis of movement related pathologies and to the ana- lysis of vocal fold vibration cycle, which in the case of VLS images it is only a human eye optical illusion. However, HSV (Kiritani et al. 1986; Kiritani et al. 1993) captures images at the speed of 5000–8000 frames/s, thus providing a great amount of physiological and movement- related vocal fold information. Its general use is limited. There are very few hospitals which own the necessary hard- ware and the price is very high, unlike VLS. There is an intermediate solution called Videokimography (VKG) * Correspondence: amaia.mendez@deusto.es 1DeustoTech-LIFE Unit, DeustoTech Institute of Technology, University of Deusto 24, Bilbao 48007, Spain Full list of author information is available at the end of the article a SpringerOpen Journal © 2012 Zorrilla et al.; licensee Springer. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Zorrilla et al. SpringerPlus 2012, 1:64 http://www.springerplus.com/content/1/1/64 which provides high resolution images at a high speed with a more accessible price than VLS (Kim et al. 2003). Videolaryngostroboscopy is the most used technique for the diagnosis of some vocal pathologies (Braunschweig et al. 2008) and the most common in the hospitals. Due to that reason, we have chosen it for the purpose of this study. Against this background, it is necessary to provide objective parameters and tools for the practice of ENT specialists, not only in the area of vocal pathology diag- nosis but also in the evaluation of the evolution of a re- habilitation process or a chirurgic intervention. ENTs as well as speech therapists use more informa- tion than that obtained merely through image acquisi- tion for their daily practice. Acoustic analysis is another one of their information sources, and although it does not serve as a diagnostic method by itself (Hadjitodorov and Mitev 2002), the pitch, jitter, shimmer and harmonics-to-noise ratio (HNR) parameters are accepted for the evaluation of voice quality and to measure the ef- ficiency of the rehabilitation. Both techniques are used for diagnosis and treatment, as in the majority of cases people go to ENT and speech therapist appointments due to hoarseness. The main aim of this work is to speed up the habitual practice of the specialists during the appointments through the automation of study methods, in response to the lack of applications which include audio and video processing functionalities together with the patient´s psychological aspect and result analysis. The authors of this work have chosen VLS images (nevertheless assuming its limitations for the detection of some pathologies) because its use is widely spread in otorhinolaryngology (and the instrumentation is avail- able in most hospitals), and focus in providing objective acoustic parameters plus VLS image information related mainly with organic dysphonia. This being the main aim, a number of secondary objectives are described as follows:  To design and develop a tool combining acoustic analysis and digital image processing which provides a report of final results according to the ELS (European Laryngological Society) guidelines.  To include different digital signal processing algorithms developed by the authors in previous works in the tool (Méndez et al. Mendez et al. 2009; Mendez et al. 2012), (García et al. 2009). The article is organized as follows: Section 2 describes materials, methods and functionalities of the designed and evaluated software. Section 3 shows the experimen- tal results of the otolaryngologists in their daily practice using the application, and finally the authors offer con- cluding remarks in Section 4. Materials and methods In this section the technical and human resources used during the development of the application are de- scribed, together with the methodology followed in its design to provide the professional with a useful tool for the daily practice. Technical resources The proposed software is developed using a combination of Java (for the user interface) and Octave (to develop the signal processing algorithms). Among the elements more widely used for the implementation of this soft- ware are databases developed in XML (eXtensible Markup Language) and image processing libraries such as JMF (Java Media Framework). The necessary hard- ware is detailed as follows: 1. PC with integrated or external video capture device. 2. Stroboscope 3. Endoscopic Camera 4. Microphone for PC Human resources In this study, 25 patients have participated during a year and all the obtained data has been registered. 18 of the 25 patients included in the study were women (72%), while 7 were men (28%), with an average age of 42, being the youngest 19 and the oldest 58 (standard devi- ation 11,43). All the patients whose sessions (voices and images) are recorded in the Hospital have signed the ethical consent to be included in this study. Methodology One of the aims of the developed tool is to provide the professional (in this case medical) with openness regarding where the data resides and how does the sys- tem work with it. In order to fulfill that purpose the interface has been designed as simple as possible, with a pleasant user-friendly visual aspect and easy to use for not technical potential users. The design of the application (made in collaboration with otolaryngologists) encompasses all the tests to be done during an appointment for voice exploration, which are organized following a comprehensive sequen- tial structure. This design follows the structure proposed by the protocols (Teatinos) as well as other internationally accepted standards such as VHI (Rodríguez et al. Rodríguez-Parra et al. 2009), Dejonkere (ELS), all assumed by the SEORL (Spanish Society of Otorhinolaryngology and Cervico-facial Pathology) (Nuñez Batalla, Núñez 2007) in its Basic Protocol for the functional evaluation of vocal pathology. The Basic Protocol proposes five basic Zorrilla et al. SpringerPlus 2012, 1:64 Page 2 of 10 http://www.springerplus.com/content/1/1/64 Figure 5 Example of vocal profile of a pathological patient. Figure 6 Audiovisual Gallery Screen. Zorrilla et al. SpringerPlus 2012, 1:64 Page 8 of 10 http://www.springerplus.com/content/1/1/64 the demarcation of the red circle, while the pathological values appear located outside the threshold circle. Thus a multidimensional graph of the patient is obtained in which the larger the area of the graph, the greater the vocal lesion, and the smaller the area of the diagram indicates a lower vocal pathology. The parameters included in the vocal profile are: 1. Subjective quality 2. Subjective repercussion 3. Perception G 4. Perception R 5. Perception B 6. MFT 7. Jitter 8. Shimmer 9. HRN 10. Stroboscopy: Close 11. Stroboscopy: Mucosal wave 12. Stroboscopy: Regularity 13. Stroboscopy: Symmetry Audiovisual gallery The audiovisual gallery is a virtual library of stroboscopic images , recorded voices and their associated diagnostic with primarily didactic purposes, since performing these exercises helps us to properly assess the patient data that will be studied in the program (see Figure 6). It is advisable to consult the audiovisual gallery to ob- tain the maximum efficiency from the studies. It consists of four libraries: 1. Stroboscopic Parameters: Models of stroboscopic images are shown with the scores of the various parameters. 2. Vocal Pathology: consist of laryngoscopic video recordings with their corresponding lesion diagnoses. 3. Perceptual Evaluation: includes audio recordings of pathological voices with evaluations of the GRBAS parameters. 4. Spectrograms: standard images consisting of different types of pathological spectrograms (I-IV) according to the criteria of Yanagihara. Subjective results Beside the objective results corresponding to the acous- tic parameters analyzed, or related to the features of the vocal cords, the software has been reviewed and analyzed by experts in otolaryngology which this way help the authors in the continuous improvement of the application. The feedback of the otolaryngologists was collected through some opinion questionnaires attached below (Table 7), and from which some conclusions were extracted. Each one of the evaluated Items has been valued from 1 to 5, being 5 totally agree and 1 totally agree, and 1 totally. As it can be seen in the Table, otolaryngologists evalu- ate especially well the graphic representations provided by the software (4,55 and 4,18), which allow to detect abnormalities in the voice and/ or in the vocal cords in a very visual way. Regarding the ease of use of ANALISISVOX and its interface the evaluation remains good 3,53 and 3,14 re- spectively. The adaptation of the software to the man- agement of the software is below one week, and the Table 7 Survey made to otolaryngologists Item Average Marks The use of the AnalisisVOX software is easy 3,53 Friendly interface 3,14 The acoustic parameters analyzed are appropriate 3,97 The graphic representation of the acoustic parameters is appropriate 4,18 The analyzed parameters of the vocal fold images are appropriate 3,82 The graphic representation of the parameters obtained automatically through the images is appropriate 4,5 Quality of the generated reports 4,47 Table 8 Comparative features of ANALISISVOX Features of the current applications Features of the ANALISISVOX application Insufficient. They do not provide the complete information the specialist doctor needs when carrying out a medical consultation. Complete. It is integrated within a single application, just the needed analyses the specialist doctor requires to diagnose (according to the ELS protocol). Inefifcient. They do not provide the specific information necessary for the specialist doctor. Efficient. An automated system is established, sequential, which makes the consultation easy and rapid /quick. Lead to the specialist doctor to carry out the exploration in parts, gathering the information through different methods, generating files and documents of different programs which occupy usable memory of the computer, and moreover slowing down the process of the study. It can be accessed to the files of any patient, without having to seek manually on the hard disk any kind of information Too technical when showing the calculated information. Shows the values obtained in a graphic and easy way to digest. Zorrilla et al. SpringerPlus 2012, 1:64 Page 9 of 10 http://www.springerplus.com/content/1/1/64 provided feedback is more related to the inclusion of new functionalities which, with problems related to those developed ones. Conclusions There are plenty of programs (Matassini and Manfredi 2002; Hadjitodorov and Mitev 2002; Gelzinis et al. 2008) which serve as a tool for doctors who study the voice dur- ing an appointment. In most cases these are applications that allow you to record your voice and emit certain fre- quency parameters, or to analyze independently the features of the voice and of the vocal fold images. However, these applications are insufficient (as it can be seen in a compari- son in Table 8) and often inefficient even when performing a medical consultation, since they do not provide complete information but only part of it. Therefore, doctors are forced to perform the exploration separately, gathering the information with different methods, generating files and documents from different software programs that fill the useful computer memory and in addition slowing the study process. It is noticeable that there is great interest aroused by these applications in the field of ENT, speech pathologists and speech therapists, but the big question is how many of them respond to the needs of specialists. In the case of the proposed tool the vision of the experts who have participated throughout the development process has been implemented, therefore its applicability is granted. The proposed application performs a post-processing of the signals supplied during a clinic session, and it uni- fies concepts and results which are usually analyzed in- dependently. The preparation of all reports with all the provided objective parameters allows the study of the evolution of the patients during the rehabilitation process or after surgery. We could even evaluate the ef- fectiveness of treatments and suggest modifications. Competing interests The authors declare that they have no competing interests. Authors' contributions These authors: AMZ, BGZ have made substantial contributions to design and development, or acquisition of algorithms and software application. The authors: API has been involved in the conception of the tool, and in revising and testing it critically. All authors read and approved the final manuscript. Acknowledgements The authors wish to acknowledge the University of Deusto, which kindly lent infrastructures and material for this research work. This research is partially supported by the Basque Country Department of Education, Universities and Research. It is also important to remark the support provided by Ainara Sudupe. Author details 1DeustoTech-LIFE Unit, DeustoTech Institute of Technology, University of Deusto 24, Bilbao 48007, Spain. 2Basurto Hospital, Bilbao, Spain. Received: 1 September 2012 Accepted: 8 December 2012 Published: 13 December 2012 References Braunschweig T, Flaschka J, Schelhorn-Neise P, Döllinger M (2008) High-speed video analysis of the phonation onset, with an application to the diagnosis of functional dysphonias. Med Eng Phys 30(1):59–66 Eysholdt U, Rosanowski F, Hoppe U (2003) Vocal fold vibration irregularities caused by different types of laryngeal asymmetry. European Arch Otorhinolaryngol 260(1):412–417 García B, Ruiz I, Méndez A, Mendezona M (2009) Objective characterization of oesophageal voice supporting medical diagnosis, rehabilitation and monitoring. Comput Biol Med 39:97–105 Gelzinis A, Verikas A, Bacauskiene M (2008) Automated speech analysis applied to laryngeal disease categorization. Comput Methods Programs Biomed 91 (1):36–47 Hadjitodorov S, Mitev P (2002) A computer system for acoustic analysis of pathological voices and laryngeal diseases screening. 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Accessed 26 August Weigelt S, Krischke S, Klotz M, Hoppe U, Köllner V, Eysholdt U, Rosanowski F (2004) Voice handicap in patients with organic and functional dysphonia. HNO 52(8):751–756 Yanagihara N (1967) Significance of harmonic changes and noise components in hoarseness. J Speech Hear Res 10:531–541 doi:10.1186/2193-1801-1-64 Cite this article as: Zorrilla et al.: Computer aided tool for diagnosis of ENT pathologies using digital signal processing of speech and stroboscopic images. SpringerPlus 2012 1:64. Zorrilla et al. SpringerPlus 2012, 1:64 Page 10 of 10 http://www.springerplus.com/content/1/1/64
Title: Computer aided tool for diagnosis of ENT pathologies using digital signal processing of speech and stroboscopic images ​
Authors: Amaia Méndez Zorrilla, Begoña García Zapirain, Agustín Pérez Izquierdo ​
Publisher: SpringerPlus
Date: 13 December 2012 ​
Abstract: The development of computer software and other technologies greatly facilitates the evaluation of pathological voice patients. ​ This fact allows to reduce exploration time, improves the reproducibility of results and creates the possibility of test protocol standardization needed for the intercommunication between the different voice specialists. ​ The proposed application encompasses the most important aspects which should be taken into account regarding dysphonic patients. ​ It is a multidimensional scope which involves subjective questionnaires and perceptual, aerodynamic, acoustic and stroboscopic evaluations. ​ In this system, the authors have designed and created simple tools for recording and automatic acoustic analysis for the acquisition and edition of stroboscopic images. The purpose is to work with all necessary tools running on a single application, without having to export and import data from other computer programs. ​ Therefore, the objective is to synthetize the basic voice and the exploration of the vocal folds, simplifying it through the design of a program which helps us to analyze step-by-step each aspect of the vocal pathology. ​ The evaluation of the tool has been performed by the otolaryngologists through periodical (medical) appointments on 25 patients for one year a year, and the results are promising either for the professionals as well as for the patients which receive a detailed report with the objective information concerning the features of their voice and vocal cords. ​