Difference between revisions of "Speech prostheses"

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[[File:Voice prosthesis wikimedia.jpg|thumbnail|right|Demonstration about how speech is generated while using a one-way valve with the finger covering the stoma.]]
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[[File:Trachea-oesophageal puncture.jpg|thumb|Tracheoesophageal voice]]
Speech prostheses, or voice prostheses, is a overall term for small, silicon one-way valves that are inserted into the tracheo-oesophageal puncture of laryngectomy patients. The prosthesis not only safely divides the oesophagus and trachea, but also allow speech when the outside of the tracheostoma, the opening on the neck to allow air in, is covered with a finger or otherwise occluded. This is greatly beneficial to patients because it allows to communicate without the need to use either an [[Electrolarynx]] or [[Speech synthesizers]].
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Speech prostheses, or voice prostheses, refer overall to small, silicon one-way valves that are inserted into the tracheoesophageal puncture of laryngectomy patients. The prosthesis not only safely divides the oesophagus and trachea, but also allows speech when the outside of the tracheostoma, the opening on the neck to allow air in, is covered with a finger or otherwise occluded. This is greatly beneficial to patients because it allows them to communicate without the need to use either an [[Electrolarynx|electrolarynx]] or [[Speech synthesizers|speech synthesizers]].
  
== Main characteristics ==
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== Main Characteristics ==
  
Oesophageal valves are made of medical grade silicon rubber and primarily consists of four parts: One-way valve, two flanges on each side of the tube, rigid valve ring in the middle of the tube, and a safety strap.<ref>Atos Medical. Provox® Vega™:The Instructions for Use Clinican's. Atos Medical [online]. Available online at: http://www.atosmedical.com/wp-content/uploads/2015/10/10879_clin.-ifu-provox-vega_201512a_web.pdf (Retrieved 17th January, 2017).</ref> The safety strap is supposed to avoid the fall of the prosthesis to the trachea during the removal of the device. The two flanges are tracheal flange and oesophageal flange respectively. They vary in rigidity and size. Both depend on the valve being patient-changeable or not, with the latter being bigger in size and rigid so as to facilitate bigger longevity. Consequently, there are two types of prostheses, indwelling and nonindwelling.<ref>Atos Medical. United States Patent US 20090043386 A1. United State's Patent and Trademark Office [online]. 2012, Aug 7. Available online at: http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=/netahtml/PTO/search-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN/8236007 (Retrieved 19th January, 2017).</ref> The overall size, especially the diameter of the tube slightly differs among speech prostheses.<ref>EERENSTEIN, Simone E. J. et al. Downsizing of Voice Prosthesis Diameter in Patients with Laryngectomy: An in Vitro Study. Arch Otolaryngol Head Neck Surg. 2002 Jul; 128(7):838-41. Doi: 10.1001/archotol.128.7.838 Available online at: http://www.webwhispers.org/library/documents/Eerenstein.pdf (Retrieved 19th January, 2017).</ref>
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Oesophageal valves are made of medical grade silicon rubber and primarily consist of four parts: a one-way valve, two flanges on each side of the tube, a rigid valve ring in the middle of the tube, and a safety strap.<ref>Atos Medical. Provox® Vega™: The Instructions for Use Clinican's. Atos Medical [online]. Available online at: http://www.atosmedical.com/wp-content/uploads/2015/10/10879_clin.-ifu-provox-vega_201512a_web.pdf (Retrieved 17th January, 2017).</ref> The safety strap is supposed to avoid the fall of the prosthesis to the trachea during the removal of the device. The two flanges are a tracheal flange and an oesophageal flange, respectively. They vary in rigidity and size. Both depend on the valve being patient-changeable or not, with the latter being larger and rigid so as to facilitate better longevity. Consequently, there are two types of prostheses, indwelling and non-indwelling.<ref>Atos Medical. United States Patent US 20090043386 A1. United State's Patent and Trademark Office [online]. 2012, Aug 7. Available online at: http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=/netahtml/PTO/search-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN/8236007 (Retrieved 19th January, 2017).</ref> The overall size, especially the diameter of the tube, slightly differs among speech prostheses.<ref name="downsizing">EERENSTEIN, Simone E. J. et al. Downsizing of Voice Prosthesis Diameter in Patients with Laryngectomy: An in Vitro Study. Arch Otolaryngol Head Neck Surg. 2002 Jul; 128(7):838-41. Doi: 10.1001/archotol.128.7.838 Available online at: http://www.webwhispers.org/library/documents/Eerenstein.pdf (Retrieved 19th January, 2017).</ref>
[[File:Prosthesis inserter.jpg|thumbnail|right|Valve attached on a inserter. The safety strap is usually cut off after the insertion.]]
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[[File:Prosthesis inserter.jpg|thumbnail|right|A valve attached to the inserter; the safety strap is usually cut off after the insertion]]
The valve is inserted into patient's throat during the surgery, where is created a puncture between the posterior tracheostoma wall and oesophagus. The size of the puncture depends on the size of the valve, since the size of an each device slightly variates. The valve is only one-way, in order to prevent leakage of saliva, food or drinks to the air ways. The speech is produced, when the air, which goes through the valve, vibrates the mucosa of a larynx. Kazi points out, however, that the achievement of a voice after the tracheo-oesophageal puncture is dependant at the further training of patients. The voice is not achieved automatically.<ref name="kazi07"/>
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The valve is inserted into the patient's throat during surgery, where a puncture is created between the posterior tracheostoma wall and the oesophagus. The size of the puncture depends on the size of the valve, since the size of each device slightly varies. The valve is only one-way, in order to prevent leakage of saliva, food, or drinks to the air-ways. The speech is produced when the air, which goes through the valve, vibrates the mucosa of the larynx. Rehan Kazi et al. point out, however, that the achievement of voice after the tracheoesophageal puncture is dependent on the further training of patients. The voice is not achieved automatically.<ref name="kazi07"/>
  
There are several companies which companies which manufacture tracheoesophageal voice prostheses, the most renowned prostheses are Blom-Singer, Groningen and Provox.<ref name="State of the Art"/>  
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There are several companies that manufacture tracheoesophageal voice prostheses; the most renowned prostheses are made by Blom-Singer, Groningen, and Provox.<ref name="cancer UK">Cancer Research UK. Speaking after laryngectomy. Cancer Research UK [online]. Available online at: http://www.cancerresearchuk.org/about-cancer/type/larynx-cancer/living/speaking-after-laryngectomy#tep (Retrieved 23rd January, 2017).</ref>
  
Patients which do not find tracheoesophageal voice prosthesis suitable for them could use [[Electrolarynx|electrolarynx]], [[Speech synthesizers|speech synthesizers]] or oesophageal voice production.<ref name="State of the Art">BROWN, Dale H. et al. Postlaryngectomy Voice Rehabilitation: State of the Art at the Millennium, World Journal of Surgery [online]. 2003, 14 May.  DOI: 10.1007/s00268-003-7107-4 Available online at: http://link.springer.com/article/10.1007/s00268-003-7107-4 (Retrieved 16th January, 2017).</ref>
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Patients who do not find tracheoesophageal voice prostheses suitable for could use the [[Electrolarynx|electrolarynx]], [[Speech synthesizers|speech synthesizers]], or oesophageal voice production.<ref name="State of the Art">BROWN, Dale H. et al. Postlaryngectomy Voice Rehabilitation: State of the Art at the Millennium, World Journal of Surgery [online]. 2003, 14 May.  DOI: 10.1007/s00268-003-7107-4 Available online at: http://link.springer.com/article/10.1007/s00268-003-7107-4 (Retrieved 16th January, 2017).</ref>
  
 
=== Historical overview ===
 
=== Historical overview ===
  
Eric D. Blom claimed that the first larengectomy restoration of a voice was made in 1931 by a patient using a red hot ice pick. The patient created a 'puncture' in the posterior wall of a tracheostoma to allow the air from lungs to enter mouth. The patient inserted a goose quill in the puncture, in order to prevent the closing of the tract. The attempts of replications of this surgery were unsuccessful, therefore the method was abandoned.<ref name="current status"/> Usage of a valve for voice restoration was first described by a Polish otolaryngologist prof. dr. Erwin Mozolewski in the 1970s.<ref>MOZOLEWSKI, Erwin S., et al. "Arytenoid vocal shunt in laryngectomized patients." The Laryngoscope 85.5 (1975): 853-861.</ref> First commercially available oesophageal valve was introduced in the late 1970s, by Eric Blom and Mark Singer. It was considered a major step in voice restoration. Laryngectomy patients were required to learn oesophageal speech or use an electrolarynx to be able to communicate again before the introduction of this procedure.<ref name="kazi07">KAZI, Rehan, et al. Surgical voice restoration following total laryngectomy. Journal of cancer research and therapeutics, 2007, 3.4: 188. Doi: 10.4103/0973-1482.38991 Available online at: http://medind.nic.in/jat/t07/i4/jatt07i4p188.htm (Retrieved 24th February, 2016).</ref> In 1985, inserting oesophageal valves has been accepted as a primary procedure in the US.<ref>HAMAKER, Ronald C., et al. Primary voice restoration at laryngectomy. Archives of Otolaryngology, 1985, 111.3: 182-186.</ref> Since then, the procedure became the de facto standard for post-laryngectomy treatment and voice restoration.<ref>HUTCHESON, Katherine A., et al. Enlarged tracheoesophageal puncture after total laryngectomy: A systematic review and meta‐analysis. Head & neck, 2011, 33.1: 20-30.</ref>
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Eric D. Blom claimed that the first laryngectomy restoration of a voice was made in 1931 by a patient using a red-hot ice pick. The patient created a 'puncture' in the posterior wall of a tracheostoma to allow air from the lungs to enter the mouth. Then he inserted a goose quill in the puncture, in order to prevent the closing of the tract. Attempts to replicate this surgery were unsuccessful, and the method was abandoned.<ref name="current status"/> Usage of a valve for voice restoration was first described by Polish otolaryngologist Erwin Mozolewski in the 1970s.<ref>MOZOLEWSKI, Erwin S., et al. "Arytenoid vocal shunt in laryngectomized patients." The Laryngoscope 85.5 (1975): 853-861.</ref> The first commercially available oesophageal valve was introduced in the late 1970s by Eric Blom and Mark Singer. It was considered a major step in voice restoration. Laryngectomy patients were required to learn oesophageal speech or use an electrolarynx to be able to communicate again before the introduction of this procedure.<ref name="kazi07">KAZI, Rehan, et al. Surgical voice restoration following total laryngectomy. Journal of cancer research and therapeutics, 2007, 3.4: 188. Doi: 10.4103/0973-1482.38991 Available online at: http://medind.nic.in/jat/t07/i4/jatt07i4p188.htm (Retrieved 24th February, 2016).</ref> Since 1985, inserting oesophageal valves has been accepted as a primary procedure in the U.S.<ref>HAMAKER, Ronald C., et al. Primary voice restoration at laryngectomy. Archives of Otolaryngology, 1985, 111.3: 182-186.</ref> Since then, the procedure became the de facto standard for post-laryngectomy treatment and voice restoration.<ref>HUTCHESON, Katherine A., et al. Enlarged tracheoesophageal puncture after total laryngectomy: A systematic review and meta‐analysis. Head & neck, 2011, 33.1: 20-30.</ref>
  
 
=== Purpose ===
 
=== Purpose ===
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== Important Dates ==
 
== Important Dates ==
  
* 1873 - Austrian surgeon Theodore Billroth performs the first laryngectomy.<ref>KAZI, R. A., et al. Christian Albert Theodor Billroth: Master of surgery. Journal of postgraduate medicine, 2004, 50.1: 82. Available online at: https://tspace.library.utoronto.ca/bitstream/1807/2074/1/jp04025.pdf (Retrieved 25th February, 2016).</ref>
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* 1873: Austrian surgeon Theodore Billroth performs the first laryngectomy.<ref>KAZI, R. A., et al. Christian Albert Theodor Billroth: Master of surgery. Journal of postgraduate medicine, 2004, 50.1: 82. Available online at: https://tspace.library.utoronto.ca/bitstream/1807/2074/1/jp04025.pdf (Retrieved 25th February, 2016).</ref>
* 1931 - A laryngectomy patient made a 'puncture' in his throat.<ref name="current status">BLOM, Eric D. Current Status of Voice Restoration Following Total Laryngectomy. Oncology [online]. 2000, Jun 1. Available online at: http://www.cancernetwork.com/head-neck-cancer/current-status-voice-restoration-following-total-laryngectomy (Retrieved 19th January, 2017).</ref>  
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* 1931: a laryngectomy patient made a 'puncture' in his throat.<ref name="current status">BLOM, Eric D. Current Status of Voice Restoration Following Total Laryngectomy. Oncology [online]. 2000, Jun 1. Available online at: http://www.cancernetwork.com/head-neck-cancer/current-status-voice-restoration-following-total-laryngectomy (Retrieved 19th January, 2017).</ref>  
* 1972 - Polish-born otolaryngologist prof. dr. Erwin Mozolewski develops a way to give back voice abilities to laryngectomy patients with a small plastic valve connecting their larynx and oesophagus. The valve was officially unveiled on a international conference in Boston in 1979.<ref>TARNOWSKA, Czesława. Wspomnienie o profesorze Erwinie Mozolewskim. Pomorski Uniwersytet Medyczny w Szczecinie [online]. Available online at: https://www.pum.edu.pl/__data/assets/file/0009/14868/Wspomnienie_o_profesorze_Erwin_7517.pdf (Retrieved 19th January, 2017).</ref>
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* 1972: Polish-born otolaryngologist Erwin Mozolewski develops a way to give back voice abilities to laryngectomy patients with a small plastic valve connecting their larynx and oesophagus. The valve was officially unveiled at an international conference in Boston in 1979.<ref>TARNOWSKA, Czesława. Wspomnienie o profesorze Erwinie Mozolewskim. Pomorski Uniwersytet Medyczny w Szczecinie [online]. Available online at: https://www.pum.edu.pl/__data/assets/file/0009/14868/Wspomnienie_o_profesorze_Erwin_7517.pdf (Retrieved 19th January, 2017).</ref>
* 1980s - The technique was popularized and made commercially available by an American company Bloom-Singer.<ref>InHealth Technologies. Blom-Singer Historic Achievements Brochure. InHealth Technologies [online]. 2008, Aug. Available online at: http://www.inhealth.com/v/vspfiles/pdf/brochures/Blom-Singer_Historic_Achievements_Brochure.pdf (Retrieved 19th January, 2017).</ref>
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* 1980s: the technique was popularized and made commercially available by the American company Bloom-Singer.<ref>InHealth Technologies. Blom-Singer Historic Achievements Brochure. InHealth Technologies [online]. 2008, Aug. Available online at: http://www.inhealth.com/v/vspfiles/pdf/brochures/Blom-Singer_Historic_Achievements_Brochure.pdf (Retrieved 19th January, 2017).</ref>
  
 
== Enhancement/Therapy/Treatment ==
 
== Enhancement/Therapy/Treatment ==
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[[File:HME.jpg|thumb|A patient using heat and moisture exchanger]]
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Healthy individuals speak when they exhalte air from their lungs through vocal cords in the larynx. The vocal cords produce a vibration, which is modulated to the speech by the lips, jaws, and tongue.<ref name="guide">BROOK, Itzhak. The Laryngectomee Guide. American Academy of Otolaryngology–Head and Neck Surgery [online]. 2015. Available online at: https://www.entnet.org/sites/default/files/LaryngectomeeGuide.pdf (Retrieved 19th January, 2017).</ref> Patients who have undergone a total laryngectomy have had their larynx removed. This causes the loss of the voice, since the vocal cords are in the part of the larynx that is removed. They cannot breathe through their mouth or nose, but they are breathing through stoma, the small uncovered hole in their neck. A tracheoesophageal voice prosthesis could be installed during a total laryngectomy or in further surgery. It aims to restore the ability to speak and bring the patient's quality of life as close as possible to the state before the laryngectomy. Patients have to cover the stoma in order to speak.<ref>Laryngopedia. Tracheoesophageal voice prosthesis (TEP). Laryngopedia [online]. 2017. Available online at: http://laryngopedia.com/tracheoesophageal-voice-prosthesis-tep/ (Retrieved 19th January, 2017).</ref>
  
Healthy individuals speak when they exalt air from their lungs through vocal cords placed in a larynx. The vocal cords produce a vibration, which is modulated to the speech by lips, jaws and tongue.<ref>BROOK, Itzhak. The Laryngectomee Guide. American Academy of Otolaryngology–Head and Neck Surgery [online]. 2015. Available online at: https://www.entnet.org/sites/default/files/LaryngectomeeGuide.pdf (Retrieved 19th January, 2017).</ref> Patients, who underwent a total laryngectomy, have removed their larynx. This cause the loss of voice since the vocal cords are placed in the part of larynx which is removed. They cannot breath through their mouth or nose, but they are breathing through stoma, the small uncover hole in their neck. Tracheoesophageal voice prosthesis could be installed during a total laryngectomy or in the further surgery. It aims to restore the ability to speak and bring the patient's quality of life as close as possible to the state before the laryngectomy. Patients have to cover they stoma, in order to speak.<ref>Laryngopedia. Tracheoesophageal voice prosthesis (TEP). Laryngopedia [online]. 2017. Available online at: http://laryngopedia.com/tracheoesophageal-voice-prosthesis-tep/ (Retrieved 19th January, 2017).</ref>  
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In comparison with oesophageal speech, the speech with a tracheoesophageal voice is easier to achieve, more fluent, louder and more intelligible. It also sounds more natural than speech provided by an electrolarynx. The disadvantages of a tracheoesophageal voice are primarily the fact that the prosthesis has to be removed a by physician and that the speech is not entirely hands-free.<ref> SERRA, A. et al. Post-laryngectomy voice rehabilitation with voice prosthesis: 15 years experience of the ENT Clinic of University of Catania. ACTA otorhinolaryngologica italica [online]. 2015; 35(6): 412-419. Doi: 10.14639/0392-100X-680 Available online at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4755057/ (Retrieved 23rd January, 2017).</ref> There are, however, covers, which allow one to speak hands-free.<ref name="HME"/>
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Laryngectomy in many cases has a negative impact on the psychological and social state of patients. It is linked with a loss of a natural voice and the impairment of taste and smell.<ref name="woman">ULBRICHT, Grace F. Laryngectomy Rehabilitation: A Woman's View Point. In: Woman and Cancer. New York: Routledge, 1987. p. 131-136. Available online at: https://books.google.cz/books?id=3Ss2iaKwEOUC&pg=PA131&lpg=PA131&dq=laryngectomee+woman&source=bl&ots=GFWRktScWg&sig=1ApLmb_KcKkd8X47JGN7SnLvpgU&hl=cs&sa=X&ved=0ahUKEwjenffHt9jRAhUFbhQKHW9eBXAQ6AEIQjAJ#v=onepage&q=laryngectomee%20woman&f=false (Retrieved 23rd January, 2017).</ref> However, Dale H. Brown and his colleagues claim that speech rehabilitation has improved recently, and that there have been refinements of patients' lives after total laryngectomy. In particular, the voice produced by a prosthesis is considered better, and prostheses are easier to handle.<ref name="State of the Art"/>
  
 
== Ethical & Health Issues ==
 
== Ethical & Health Issues ==
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[[File:Voice prosthesis wikimedia.jpg|thumbnail|left|Demonstration about how speech is generated while using a one-way valve with the finger covering the stoma]]
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Some patients may find the uncovered stoma embarrassing and would like to cover the puncture in their necks. There are several options to cover stoma: many tracheostoma covers, filters, and protectors are available on the market. These cloths or plastic covers resemble the top of a turtle-neck or perhaps a baby bib and are available in different colours and designs.<ref>Luminaud Inc. Luminaud: Speech, Voice and Communication Products. Luminaud Inc. [online]. Available online at: http://u.b5z.net/i/u/10204675/f/CF0615pdfbw_c.pdf (Retrieved 17th January, 2017).</ref> The neck could also be covered with a scarf or light clothes. There are also various necklaces, which are available for women-laryngectomees.<ref>GARDNER, Warren H., HARRIS, Harold E. Aids and Devices for Laryngectomees.  Arch Otolaryngol 73(2) [online]. 1961: 145-152. Doi: 10.1001/archotol.1961.00740020151003 Available online at: http://jamanetwork.com/journals/jamaotolaryngology/article-abstract/1766151 (Retrieved 17th January, 2017).</ref> The need to cover the tracheostoma is also a medical one. The puncture opens the inside of the trachea to the elements and liquids. A flexible cover and filter is usually put into the puncture to protect the trachea and provide moisture to inhaled air. In addition, certain covers could also help laryngectomees with tracheoesophageal voice prostheses to speak hands-free.<ref name="HME">Atos Medical. Provox HMEs and speaking valves. Atos Medical [online]. Available online at: http://www.atosmedical.com/laryngectomy/living-with-laryngectomy/the-provox-solution/ (Retrieved 20th January, 2017).</ref>
  
Some patients may find the uncovered stoma embarrassing and would like to cover the puncture in their necks. To do so, many tracheostoma covers, filters, and protectors are available on the market. These cloths or plastic covers range resemble the top of a turtle-neck or perhaps a baby bib and are available in different colours and designs.
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Grace F. Ulbricht points out that the speech after a total laryngectomy has a low pitch for women. Consequently, some women refuse to use any artificial speech due to this fact.<ref name="woman"/> The voice after total laryngectomy, which is produced by prostheses is more man-like.<ref> TEN HALLERS, E. J. O. et al. Difficulties in the fixation of prostheses for voice rehabilitation after laryngectomy. Acta Oto-Laryngologica [online]. 2009, Jul 8. Doi: 10.1080/00016480510031506 Available online at: http://www.tandfonline.com/doi/abs/10.1080/00016480510031506 (Retrieved 23rd January, 2017).</ref>
  
The need to cover the tracheostoma is also medical one. The puncture opens the inside of the trachea to elements and liquids. A flexible cover and filter is usually put into the puncture to protect the trachea and provide moisture to inhaled air. Other exposure problem arises from the inside of the patients body. The one-way valve inserted in the tracheo-oesophageal puncture is exposed to the body's defensive mechanisms and gets covered by a biofilm relatively quickly. This is offset by covering the valve with silver oxide that hinders unwanted biological growth on the valve. The valve can also get damaged by acidic reflux from the stomach. (TODO: add picture) These effects can not be mitigated and the valve has to be replaced.
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Each speech prosthesis has a certain life-time and then has to be replaced. There are several factors that influence the life of voice prostheses, such as geographical regions, nutrition, granulation, and infection.<ref name="modern voice"/> The life time of the prosthesis could also be shortened by inappropriate hygiene, reflux, tracheoesophageal puncture tract dilatation, or when the prosthesis does not fit properly.<ref name="guide"/> 
  
Health - leakage, http://www.webwhispers.org/library/documents/BlomLtr.pdf  http://www.webwhispers.org/library/TEPProsthesis.asp
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The prosthesis should be cleaned properly and regularly, in order to avoid the rise of microorganisms, primarily yeast. The occurrence of microorganisms badly affects the closure of a valve and could lead to the leakage of saliva or nutriment.<ref name="guide"/> In order to avoid the growth of biofilm, the valve can be covered with silver oxide, which hinders unwanted biological growth.<ref name="modern voice">KRESS, P., SCHÄFER, P., SCHWERDTFEGER, F.P., RÖSLER, S. Are modern voice prostheses better? A lifetime comparison of 749 voice prostheses. European Archives of Oto-Rhino-Laryngology. 2014; 271(1): 133-140. Doi: 10.1007/s00405-013-2611-0. Available online at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3889693/ (Retrieved 23rd January, 2017).</ref> The valve can also be damaged by acidic reflux from the stomach. These effects cannot be mitigated, and the valve has to be replaced. Furthermore, Blake LeBlanc and his colleagues claim that the risk of reflux might be increased by laryngeal therapy.<ref>LEBLANC, Blake et al. Increased Pharyngeal Reflux in Patients Treated for Laryngeal Cancer: A Pilot Study. Otolaryngology–Head and Neck Surgery [online]. 2015, Aug 25. Doi: 10.1177/0194599815601026 Available online at: http://journals.sagepub.com/doi/pdf/10.1177/0194599815601026 (Retrieved 23rd January, 2017).</ref>
  
sanitation,  
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Leakage could also be caused by tracheoesophageal puncture tract dilatation. This defect could be healed in many cases by conservative treatment. In contrast, the surgical closure of these fistulas has not been as successful.<ref>CHATURVEDI, P., PAWAR, P., DHOLAM, K. et al. A Novel Obturator Device for Management of Dilated Trachea-esophageal Puncture Tract Fistulas. Indian Journal of Otolaryngology and Head & Neck Surgery. 2013; 65(1): 3-5. Doi: 10.1007/s12070-012-0556-z Available online at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3585561/ (Retrieved 23rd January, 2017).</ref>
  
valves need replacement,  
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Simone E. J. Eerenstein and her colleagues argued that the increase of the diameter of prostheses could also lead to leakage.<ref name="downsizing"/> This claim has also been supported by Eric D. Blom, the manufacturer of Blom-Singer voice prostheses, who pointed out several papers demonstrating that prostheses with greater diameters leaked more often.<ref>BLOM, Eric D. Some comments on the escalation of tracheoesophageal voice prosthesis dimensions. Arch Otolaryngol Head Neck Surg. 2003 Apr; 129(4):500-2. Doi:10.1001/archotol.129.4.500-a Available online at: http://jamanetwork.com/journals/jamaotolaryngology/article-abstract/483807 (Retrieved 20th January, 2017).</ref>
  
heat & moisture (https://en.wikipedia.org/wiki/Heat_and_moisture_exchanger_after_laryngectomy), https://en.wikipedia.org/wiki/Esophageal_speech
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The spasm of pharyngeal muscles or swelling might cause post-tracheoesophageal puncture patients to be unable to speak, but this complication can be overcome by medical treatment.<ref name="cancer UK"/>
  
puncture healing
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== Public & Media Impact and Presentation ==
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[[File:Noëlle Klien.png|thumb|Noëlle Klein]]
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There are various laryngectomy support groups, e.g., [http://www.webwhispers.org/index.asp WebWhispers], [http://www.stilltalking.org/ StillTalking.org], [http://www.thentls.com/ The North Texas Laryngectomy Society], and the [http://www.laryngectomy.org.uk/ National Association of Laryngectomee Clubs]. Information about laryngectomy can also be  found on the websites of certain hospitals and health centres, e.g., [https://www.mskcc.org/cancer-care/patient-education/about-your-total-laryngectomy Memorial Sloan Kettering Cancer Center], the [http://www.upmc.com/patients-visitors/education/cancer/Pages/total-laryngectomy.aspx University of Pittsburgh Medical Center], and [http://www.uhn.ca/PatientsFamilies/Health_Information/Health_Topics/Documents/Laryngectomy.pdf University Health Network].
  
maintaining the prosthesis
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Laryngectomy is also discussed at websites focused on cancer treatment, such as [http://www.cancerresearchuk.org/about-cancer/type/larynx-cancer/living/stoma/starting-out-with-a-breathing-stoma Cancer Research UK], [http://www.headandneckcancerguide.org/adults/cancer-diagnosis-treatments/surgery-and-rehabilitation/cancer-removal-surgeries/laryngectomy/ Head & Neck Cancer Guide], and [https://www.macmillan.org.uk/cancerinformation/cancertypes/larynx/treatinglaryngealcancer/voicerestoration.aspx Macmillan Cancer Support].
  
== Public & Media Impact and Presentation ==
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Additionally, several guides have been published electronically, which could help patients to deal with their new state. these include, [http://www.swslhd.nsw.gov.au/cancer/pdf/goinghome.pdf Going Home with a Laryngectomy Stoma: A Guide for Patients and Carers], [http://www.laryngectomy.org.uk/files/7013/8600/0359/NALC_Handbook.pdf Handbook for Laryngectomy Patients], [http://electrolarynx.com/Self_Help_for_the_Laryngectomee_book.pdf Self Help for the Laryngectomee], and [https://www.entnet.org/sites/default/files/LaryngectomeeGuide.pdf The Laryngectomee Guide].
  
TODO: Cancer support groups and websites.
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Noëlle Klein, the woman with a speech prosthesis, points out that her new voice sounds like a  man's voice. However, she advises women who are preparing for a laryngectomy to get a laryngectomy, since it gives them a chance to live.<ref>Atos Medical channel. Life as a laryngectomee - Noëlle Klein. Youtube [online]. 2012, Feb 2. Available online at: https://www.youtube.com/watch?v=wj73cOrIgIk (Retrieved 23rd January, 2017).</ref>
  
 
== Public Policy ==
 
== Public Policy ==
  
tracheo-oesophageal puncture considered primary practice and policy in hospitals???
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Voice prostheses are regulated by the FDA and similar agencies in each country. Provox<ref>Atos Medical. Compliance. Atos Medical [online]. Available online at: http://www.atosmedical.com/compliance/ (Retrieved 24th January, 2017).</ref> and Blom-Singer<ref>U.S. Food and Drug Administration. Helix Medical, Inc. 510(k) Summary, Blom-Singer Indwelling 2000 Voice Prosthesis. U.S. Food and Drug Administration [online]. 1999, Jun 25. Available online at: https://www.accessdata.fda.gov/cdrh_docs/pdf/K991587.pdf (Retrieved 24th January, 2017).</ref><ref>InHealth Technologies. Certificate Number: 560023. InHealth Technologies [online]. Available online at: http://www.inhealth.com/v/vspfiles/pdf/info/Freudenberg_560023_ISO_13485_plus_addenda_Oct_18_2015.pdf (Retrieved 24th January, 2017).</ref><ref>InHealth Technologies. EC Certificate Number: 2001334CE01. InHealth Technologies [online]. Available online at: http://www.inhealth.com/v/vspfiles/pdf/info/Freudenberg_2001334CE01_Oct_18_2015.pdf (Retrieved 24th January, 2017).</ref><ref>InHealth Technologies. EC Certificate Number: 2001334CE04. InHealth Technologies [online]. Available online at: http://www.inhealth.com/v/vspfiles/pdf/info/Freudenberg_2001334CE04_Oct_18_2015.pdf (Retrieved 24th January, 2017).</ref><ref>InHealth Technologies. EC Certificate Number: 2001334CE05. InHealth Technologies [online]. Available online at: http://www.inhealth.com/v/vspfiles/pdf/info/Freudenberg_2001334CE05_Oct_18_2015.pdf (Retrieved 24th January, 2017).</ref> comply with several regulations.
 
 
== Related Technologies, Projects or Scientific Research ==
 
 
 
Brush, flush, plug http://www.atosmedical.com/wp-content/uploads/2015/12/7962us_life-as-a-laryngectomee-brochure-201009a.pdf  
 
 
 
TODO: Add list and pictures of specific valves.
 
 
 
https://www.inhealth.com/category_s/44.htm
 
  
http://www.cancerresearchuk.org/about-cancer/type/larynx-cancer/living/stoma/starting-out-with-a-breathing-stoma
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Several patents are associated with tracheoesophageal prostheses, such as Provox<ref>Atos Medical. Patents. Atos Medical [online]. Available online at: http://www.atosmedical.com/wp-content/uploads/2017/01/170104-atos-patents-webpage.pdf (Retrieved 24th January, 2017).</ref> and Blom-Singer.<ref>InHealth Technologies. InHealth Technologies Patents. InHealth Technologies [online]. Available online at: http://www.inhealth.com/category_s/53.htm (Retrieved 24th January, 2017).</ref>
  
http://www.webwhispers.org/library/tepprosthesis.asp
+
== Related Technologies, Projects, or Scientific Research ==
  
https://en.wikipedia.org/wiki/Voice_prosthesis
+
There are several devices that are utilized in the maintenance of voice prostheses. The cleaning of voice prostheses is facilitated by brushes and flushes.<ref>Practical SLP Info. Cleaning Your Voice Prosthesis. Practical SLP Info [online]. Available online at: http://www.practicalslpinfo.com/cleaning-your-voice-prosthesis.html (Retrieved 24th January, 2017).</ref> Leakage from a prosthesis can be avoided by use of a plug.<ref> InHealth Technologies. Voice Prosthesis Accessories. InHealth Technologies [online]. Available online at: http://www.inhealth.com/category_s/53.htm (Retrieved 24th January, 2017).</ref><ref name="Atos Accessory"> Atos Medical. Patient Information Brochure: Life as a Laryngectomee. Atos Medical [online]. Available online at: http://www.atosmedical.com/wp-content/uploads/2015/12/7962us_life-as-a-laryngectomee-brochure-201009a.pdf (Retrieved 24th January, 2017).</ref>
  
http://medind.nic.in/jat/t07/i4/jatt07i4p188.htm
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There are also devices that provide laryngectomees with more comfort in general, such as heat and moisture exchanger (HME), stoma buttons, and stoma covers.<ref name="Atos Accessory"/><ref> InHealth Technologies. Stoma Protection & Accessories . InHealth Technologies [online]. Available online at: http://www.inhealth.com/category_s/80.htm (Retrieved 24th January, 2017).</ref>
  
 
== References ==
 
== References ==

Latest revision as of 14:04, 14 July 2017

Tracheoesophageal voice

Speech prostheses, or voice prostheses, refer overall to small, silicon one-way valves that are inserted into the tracheoesophageal puncture of laryngectomy patients. The prosthesis not only safely divides the oesophagus and trachea, but also allows speech when the outside of the tracheostoma, the opening on the neck to allow air in, is covered with a finger or otherwise occluded. This is greatly beneficial to patients because it allows them to communicate without the need to use either an electrolarynx or speech synthesizers.

Main Characteristics

Oesophageal valves are made of medical grade silicon rubber and primarily consist of four parts: a one-way valve, two flanges on each side of the tube, a rigid valve ring in the middle of the tube, and a safety strap.[1] The safety strap is supposed to avoid the fall of the prosthesis to the trachea during the removal of the device. The two flanges are a tracheal flange and an oesophageal flange, respectively. They vary in rigidity and size. Both depend on the valve being patient-changeable or not, with the latter being larger and rigid so as to facilitate better longevity. Consequently, there are two types of prostheses, indwelling and non-indwelling.[2] The overall size, especially the diameter of the tube, slightly differs among speech prostheses.[3]

A valve attached to the inserter; the safety strap is usually cut off after the insertion

The valve is inserted into the patient's throat during surgery, where a puncture is created between the posterior tracheostoma wall and the oesophagus. The size of the puncture depends on the size of the valve, since the size of each device slightly varies. The valve is only one-way, in order to prevent leakage of saliva, food, or drinks to the air-ways. The speech is produced when the air, which goes through the valve, vibrates the mucosa of the larynx. Rehan Kazi et al. point out, however, that the achievement of voice after the tracheoesophageal puncture is dependent on the further training of patients. The voice is not achieved automatically.[4]

There are several companies that manufacture tracheoesophageal voice prostheses; the most renowned prostheses are made by Blom-Singer, Groningen, and Provox.[5]

Patients who do not find tracheoesophageal voice prostheses suitable for could use the electrolarynx, speech synthesizers, or oesophageal voice production.[6]

Historical overview

Eric D. Blom claimed that the first laryngectomy restoration of a voice was made in 1931 by a patient using a red-hot ice pick. The patient created a 'puncture' in the posterior wall of a tracheostoma to allow air from the lungs to enter the mouth. Then he inserted a goose quill in the puncture, in order to prevent the closing of the tract. Attempts to replicate this surgery were unsuccessful, and the method was abandoned.[7] Usage of a valve for voice restoration was first described by Polish otolaryngologist Erwin Mozolewski in the 1970s.[8] The first commercially available oesophageal valve was introduced in the late 1970s by Eric Blom and Mark Singer. It was considered a major step in voice restoration. Laryngectomy patients were required to learn oesophageal speech or use an electrolarynx to be able to communicate again before the introduction of this procedure.[4] Since 1985, inserting oesophageal valves has been accepted as a primary procedure in the U.S.[9] Since then, the procedure became the de facto standard for post-laryngectomy treatment and voice restoration.[10]

Purpose

The purpose of speech prostheses is to return the ability to speak to patients after total laryngectomy.

Important Dates

  • 1873: Austrian surgeon Theodore Billroth performs the first laryngectomy.[11]
  • 1931: a laryngectomy patient made a 'puncture' in his throat.[7]
  • 1972: Polish-born otolaryngologist Erwin Mozolewski develops a way to give back voice abilities to laryngectomy patients with a small plastic valve connecting their larynx and oesophagus. The valve was officially unveiled at an international conference in Boston in 1979.[12]
  • 1980s: the technique was popularized and made commercially available by the American company Bloom-Singer.[13]

Enhancement/Therapy/Treatment

A patient using heat and moisture exchanger

Healthy individuals speak when they exhalte air from their lungs through vocal cords in the larynx. The vocal cords produce a vibration, which is modulated to the speech by the lips, jaws, and tongue.[14] Patients who have undergone a total laryngectomy have had their larynx removed. This causes the loss of the voice, since the vocal cords are in the part of the larynx that is removed. They cannot breathe through their mouth or nose, but they are breathing through stoma, the small uncovered hole in their neck. A tracheoesophageal voice prosthesis could be installed during a total laryngectomy or in further surgery. It aims to restore the ability to speak and bring the patient's quality of life as close as possible to the state before the laryngectomy. Patients have to cover the stoma in order to speak.[15]

In comparison with oesophageal speech, the speech with a tracheoesophageal voice is easier to achieve, more fluent, louder and more intelligible. It also sounds more natural than speech provided by an electrolarynx. The disadvantages of a tracheoesophageal voice are primarily the fact that the prosthesis has to be removed a by physician and that the speech is not entirely hands-free.[16] There are, however, covers, which allow one to speak hands-free.[17]

Laryngectomy in many cases has a negative impact on the psychological and social state of patients. It is linked with a loss of a natural voice and the impairment of taste and smell.[18] However, Dale H. Brown and his colleagues claim that speech rehabilitation has improved recently, and that there have been refinements of patients' lives after total laryngectomy. In particular, the voice produced by a prosthesis is considered better, and prostheses are easier to handle.[6]

Ethical & Health Issues

Demonstration about how speech is generated while using a one-way valve with the finger covering the stoma

Some patients may find the uncovered stoma embarrassing and would like to cover the puncture in their necks. There are several options to cover stoma: many tracheostoma covers, filters, and protectors are available on the market. These cloths or plastic covers resemble the top of a turtle-neck or perhaps a baby bib and are available in different colours and designs.[19] The neck could also be covered with a scarf or light clothes. There are also various necklaces, which are available for women-laryngectomees.[20] The need to cover the tracheostoma is also a medical one. The puncture opens the inside of the trachea to the elements and liquids. A flexible cover and filter is usually put into the puncture to protect the trachea and provide moisture to inhaled air. In addition, certain covers could also help laryngectomees with tracheoesophageal voice prostheses to speak hands-free.[17]

Grace F. Ulbricht points out that the speech after a total laryngectomy has a low pitch for women. Consequently, some women refuse to use any artificial speech due to this fact.[18] The voice after total laryngectomy, which is produced by prostheses is more man-like.[21]

Each speech prosthesis has a certain life-time and then has to be replaced. There are several factors that influence the life of voice prostheses, such as geographical regions, nutrition, granulation, and infection.[22] The life time of the prosthesis could also be shortened by inappropriate hygiene, reflux, tracheoesophageal puncture tract dilatation, or when the prosthesis does not fit properly.[14]

The prosthesis should be cleaned properly and regularly, in order to avoid the rise of microorganisms, primarily yeast. The occurrence of microorganisms badly affects the closure of a valve and could lead to the leakage of saliva or nutriment.[14] In order to avoid the growth of biofilm, the valve can be covered with silver oxide, which hinders unwanted biological growth.[22] The valve can also be damaged by acidic reflux from the stomach. These effects cannot be mitigated, and the valve has to be replaced. Furthermore, Blake LeBlanc and his colleagues claim that the risk of reflux might be increased by laryngeal therapy.[23]

Leakage could also be caused by tracheoesophageal puncture tract dilatation. This defect could be healed in many cases by conservative treatment. In contrast, the surgical closure of these fistulas has not been as successful.[24]

Simone E. J. Eerenstein and her colleagues argued that the increase of the diameter of prostheses could also lead to leakage.[3] This claim has also been supported by Eric D. Blom, the manufacturer of Blom-Singer voice prostheses, who pointed out several papers demonstrating that prostheses with greater diameters leaked more often.[25]

The spasm of pharyngeal muscles or swelling might cause post-tracheoesophageal puncture patients to be unable to speak, but this complication can be overcome by medical treatment.[5]

Public & Media Impact and Presentation

Noëlle Klein

There are various laryngectomy support groups, e.g., WebWhispers, StillTalking.org, The North Texas Laryngectomy Society, and the National Association of Laryngectomee Clubs. Information about laryngectomy can also be found on the websites of certain hospitals and health centres, e.g., Memorial Sloan Kettering Cancer Center, the University of Pittsburgh Medical Center, and University Health Network.

Laryngectomy is also discussed at websites focused on cancer treatment, such as Cancer Research UK, Head & Neck Cancer Guide, and Macmillan Cancer Support.

Additionally, several guides have been published electronically, which could help patients to deal with their new state. these include, Going Home with a Laryngectomy Stoma: A Guide for Patients and Carers, Handbook for Laryngectomy Patients, Self Help for the Laryngectomee, and The Laryngectomee Guide.

Noëlle Klein, the woman with a speech prosthesis, points out that her new voice sounds like a man's voice. However, she advises women who are preparing for a laryngectomy to get a laryngectomy, since it gives them a chance to live.[26]

Public Policy

Voice prostheses are regulated by the FDA and similar agencies in each country. Provox[27] and Blom-Singer[28][29][30][31][32] comply with several regulations.

Several patents are associated with tracheoesophageal prostheses, such as Provox[33] and Blom-Singer.[34]

Related Technologies, Projects, or Scientific Research

There are several devices that are utilized in the maintenance of voice prostheses. The cleaning of voice prostheses is facilitated by brushes and flushes.[35] Leakage from a prosthesis can be avoided by use of a plug.[36][37]

There are also devices that provide laryngectomees with more comfort in general, such as heat and moisture exchanger (HME), stoma buttons, and stoma covers.[37][38]

References

  1. Atos Medical. Provox® Vega™: The Instructions for Use Clinican's. Atos Medical [online]. Available online at: http://www.atosmedical.com/wp-content/uploads/2015/10/10879_clin.-ifu-provox-vega_201512a_web.pdf (Retrieved 17th January, 2017).
  2. Atos Medical. United States Patent US 20090043386 A1. United State's Patent and Trademark Office [online]. 2012, Aug 7. Available online at: http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=/netahtml/PTO/search-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN/8236007 (Retrieved 19th January, 2017).
  3. 3.0 3.1 EERENSTEIN, Simone E. J. et al. Downsizing of Voice Prosthesis Diameter in Patients with Laryngectomy: An in Vitro Study. Arch Otolaryngol Head Neck Surg. 2002 Jul; 128(7):838-41. Doi: 10.1001/archotol.128.7.838 Available online at: http://www.webwhispers.org/library/documents/Eerenstein.pdf (Retrieved 19th January, 2017).
  4. 4.0 4.1 KAZI, Rehan, et al. Surgical voice restoration following total laryngectomy. Journal of cancer research and therapeutics, 2007, 3.4: 188. Doi: 10.4103/0973-1482.38991 Available online at: http://medind.nic.in/jat/t07/i4/jatt07i4p188.htm (Retrieved 24th February, 2016).
  5. 5.0 5.1 Cancer Research UK. Speaking after laryngectomy. Cancer Research UK [online]. Available online at: http://www.cancerresearchuk.org/about-cancer/type/larynx-cancer/living/speaking-after-laryngectomy#tep (Retrieved 23rd January, 2017).
  6. 6.0 6.1 BROWN, Dale H. et al. Postlaryngectomy Voice Rehabilitation: State of the Art at the Millennium, World Journal of Surgery [online]. 2003, 14 May. DOI: 10.1007/s00268-003-7107-4 Available online at: http://link.springer.com/article/10.1007/s00268-003-7107-4 (Retrieved 16th January, 2017).
  7. 7.0 7.1 BLOM, Eric D. Current Status of Voice Restoration Following Total Laryngectomy. Oncology [online]. 2000, Jun 1. Available online at: http://www.cancernetwork.com/head-neck-cancer/current-status-voice-restoration-following-total-laryngectomy (Retrieved 19th January, 2017).
  8. MOZOLEWSKI, Erwin S., et al. "Arytenoid vocal shunt in laryngectomized patients." The Laryngoscope 85.5 (1975): 853-861.
  9. HAMAKER, Ronald C., et al. Primary voice restoration at laryngectomy. Archives of Otolaryngology, 1985, 111.3: 182-186.
  10. HUTCHESON, Katherine A., et al. Enlarged tracheoesophageal puncture after total laryngectomy: A systematic review and meta‐analysis. Head & neck, 2011, 33.1: 20-30.
  11. KAZI, R. A., et al. Christian Albert Theodor Billroth: Master of surgery. Journal of postgraduate medicine, 2004, 50.1: 82. Available online at: https://tspace.library.utoronto.ca/bitstream/1807/2074/1/jp04025.pdf (Retrieved 25th February, 2016).
  12. TARNOWSKA, Czesława. Wspomnienie o profesorze Erwinie Mozolewskim. Pomorski Uniwersytet Medyczny w Szczecinie [online]. Available online at: https://www.pum.edu.pl/__data/assets/file/0009/14868/Wspomnienie_o_profesorze_Erwin_7517.pdf (Retrieved 19th January, 2017).
  13. InHealth Technologies. Blom-Singer Historic Achievements Brochure. InHealth Technologies [online]. 2008, Aug. Available online at: http://www.inhealth.com/v/vspfiles/pdf/brochures/Blom-Singer_Historic_Achievements_Brochure.pdf (Retrieved 19th January, 2017).
  14. 14.0 14.1 14.2 BROOK, Itzhak. The Laryngectomee Guide. American Academy of Otolaryngology–Head and Neck Surgery [online]. 2015. Available online at: https://www.entnet.org/sites/default/files/LaryngectomeeGuide.pdf (Retrieved 19th January, 2017).
  15. Laryngopedia. Tracheoesophageal voice prosthesis (TEP). Laryngopedia [online]. 2017. Available online at: http://laryngopedia.com/tracheoesophageal-voice-prosthesis-tep/ (Retrieved 19th January, 2017).
  16. SERRA, A. et al. Post-laryngectomy voice rehabilitation with voice prosthesis: 15 years experience of the ENT Clinic of University of Catania. ACTA otorhinolaryngologica italica [online]. 2015; 35(6): 412-419. Doi: 10.14639/0392-100X-680 Available online at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4755057/ (Retrieved 23rd January, 2017).
  17. 17.0 17.1 Atos Medical. Provox HMEs and speaking valves. Atos Medical [online]. Available online at: http://www.atosmedical.com/laryngectomy/living-with-laryngectomy/the-provox-solution/ (Retrieved 20th January, 2017).
  18. 18.0 18.1 ULBRICHT, Grace F. Laryngectomy Rehabilitation: A Woman's View Point. In: Woman and Cancer. New York: Routledge, 1987. p. 131-136. Available online at: https://books.google.cz/books?id=3Ss2iaKwEOUC&pg=PA131&lpg=PA131&dq=laryngectomee+woman&source=bl&ots=GFWRktScWg&sig=1ApLmb_KcKkd8X47JGN7SnLvpgU&hl=cs&sa=X&ved=0ahUKEwjenffHt9jRAhUFbhQKHW9eBXAQ6AEIQjAJ#v=onepage&q=laryngectomee%20woman&f=false (Retrieved 23rd January, 2017).
  19. Luminaud Inc. Luminaud: Speech, Voice and Communication Products. Luminaud Inc. [online]. Available online at: http://u.b5z.net/i/u/10204675/f/CF0615pdfbw_c.pdf (Retrieved 17th January, 2017).
  20. GARDNER, Warren H., HARRIS, Harold E. Aids and Devices for Laryngectomees. Arch Otolaryngol 73(2) [online]. 1961: 145-152. Doi: 10.1001/archotol.1961.00740020151003 Available online at: http://jamanetwork.com/journals/jamaotolaryngology/article-abstract/1766151 (Retrieved 17th January, 2017).
  21. TEN HALLERS, E. J. O. et al. Difficulties in the fixation of prostheses for voice rehabilitation after laryngectomy. Acta Oto-Laryngologica [online]. 2009, Jul 8. Doi: 10.1080/00016480510031506 Available online at: http://www.tandfonline.com/doi/abs/10.1080/00016480510031506 (Retrieved 23rd January, 2017).
  22. 22.0 22.1 KRESS, P., SCHÄFER, P., SCHWERDTFEGER, F.P., RÖSLER, S. Are modern voice prostheses better? A lifetime comparison of 749 voice prostheses. European Archives of Oto-Rhino-Laryngology. 2014; 271(1): 133-140. Doi: 10.1007/s00405-013-2611-0. Available online at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3889693/ (Retrieved 23rd January, 2017).
  23. LEBLANC, Blake et al. Increased Pharyngeal Reflux in Patients Treated for Laryngeal Cancer: A Pilot Study. Otolaryngology–Head and Neck Surgery [online]. 2015, Aug 25. Doi: 10.1177/0194599815601026 Available online at: http://journals.sagepub.com/doi/pdf/10.1177/0194599815601026 (Retrieved 23rd January, 2017).
  24. CHATURVEDI, P., PAWAR, P., DHOLAM, K. et al. A Novel Obturator Device for Management of Dilated Trachea-esophageal Puncture Tract Fistulas. Indian Journal of Otolaryngology and Head & Neck Surgery. 2013; 65(1): 3-5. Doi: 10.1007/s12070-012-0556-z Available online at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3585561/ (Retrieved 23rd January, 2017).
  25. BLOM, Eric D. Some comments on the escalation of tracheoesophageal voice prosthesis dimensions. Arch Otolaryngol Head Neck Surg. 2003 Apr; 129(4):500-2. Doi:10.1001/archotol.129.4.500-a Available online at: http://jamanetwork.com/journals/jamaotolaryngology/article-abstract/483807 (Retrieved 20th January, 2017).
  26. Atos Medical channel. Life as a laryngectomee - Noëlle Klein. Youtube [online]. 2012, Feb 2. Available online at: https://www.youtube.com/watch?v=wj73cOrIgIk (Retrieved 23rd January, 2017).
  27. Atos Medical. Compliance. Atos Medical [online]. Available online at: http://www.atosmedical.com/compliance/ (Retrieved 24th January, 2017).
  28. U.S. Food and Drug Administration. Helix Medical, Inc. 510(k) Summary, Blom-Singer Indwelling 2000 Voice Prosthesis. U.S. Food and Drug Administration [online]. 1999, Jun 25. Available online at: https://www.accessdata.fda.gov/cdrh_docs/pdf/K991587.pdf (Retrieved 24th January, 2017).
  29. InHealth Technologies. Certificate Number: 560023. InHealth Technologies [online]. Available online at: http://www.inhealth.com/v/vspfiles/pdf/info/Freudenberg_560023_ISO_13485_plus_addenda_Oct_18_2015.pdf (Retrieved 24th January, 2017).
  30. InHealth Technologies. EC Certificate Number: 2001334CE01. InHealth Technologies [online]. Available online at: http://www.inhealth.com/v/vspfiles/pdf/info/Freudenberg_2001334CE01_Oct_18_2015.pdf (Retrieved 24th January, 2017).
  31. InHealth Technologies. EC Certificate Number: 2001334CE04. InHealth Technologies [online]. Available online at: http://www.inhealth.com/v/vspfiles/pdf/info/Freudenberg_2001334CE04_Oct_18_2015.pdf (Retrieved 24th January, 2017).
  32. InHealth Technologies. EC Certificate Number: 2001334CE05. InHealth Technologies [online]. Available online at: http://www.inhealth.com/v/vspfiles/pdf/info/Freudenberg_2001334CE05_Oct_18_2015.pdf (Retrieved 24th January, 2017).
  33. Atos Medical. Patents. Atos Medical [online]. Available online at: http://www.atosmedical.com/wp-content/uploads/2017/01/170104-atos-patents-webpage.pdf (Retrieved 24th January, 2017).
  34. InHealth Technologies. InHealth Technologies Patents. InHealth Technologies [online]. Available online at: http://www.inhealth.com/category_s/53.htm (Retrieved 24th January, 2017).
  35. Practical SLP Info. Cleaning Your Voice Prosthesis. Practical SLP Info [online]. Available online at: http://www.practicalslpinfo.com/cleaning-your-voice-prosthesis.html (Retrieved 24th January, 2017).
  36. InHealth Technologies. Voice Prosthesis Accessories. InHealth Technologies [online]. Available online at: http://www.inhealth.com/category_s/53.htm (Retrieved 24th January, 2017).
  37. 37.0 37.1 Atos Medical. Patient Information Brochure: Life as a Laryngectomee. Atos Medical [online]. Available online at: http://www.atosmedical.com/wp-content/uploads/2015/12/7962us_life-as-a-laryngectomee-brochure-201009a.pdf (Retrieved 24th January, 2017).
  38. InHealth Technologies. Stoma Protection & Accessories . InHealth Technologies [online]. Available online at: http://www.inhealth.com/category_s/80.htm (Retrieved 24th January, 2017).