Design and development of a device to aid in tissue flap monitoring

Neaves, Kevin Mark (2016-03)

Thesis (MEng)--Stellenbosch University, 2016.

Thesis

ENGLISH ABSTRACT: Tissue flaps form an important part of plastic and reconstructive surgery. They are transferred with their own blood supply and are typically applied to wounds where skin grafts are unsuitable. Monitoring of tissue flaps is an important practice as it can assist in determining flap condition and the detection of circulatory complications. Detecting complications timeously is beneficial if the flap is to be salvaged. In the case of pedicled groin flaps, a technique known as ischemic preconditioning (IP) has proven to be beneficial in promoting early flap separation. A literature survey revealed that IP has only been manually implemented and an automated procedure would benefit patient and staff, particularly in a South African public hospital setting. A device was designed and developed which makes use of pulse oximetry to assist in tissue flap monitoring and analyses of current IP protocols. The device is capable of monitoring and recording information including the oxygen saturation (SpO2) and photoplethysmogram (PPG) measured from three different sites. In addition to this, the device automated the IP process by controlling the inflation of a pneumatic tourniquet. Several device tests were performed prior to clinical trials, including functionality tests which indicated that the device is capable of measurements on those areas of the body that are relevant to tissue flaps. Tests indicated that the device should not be limited to the monitoring of a single tissue flap type. The completed device was delivered to a plastic and reconstructive surgeon who carried out the clinical trials at Chris Hani Baragwanath Hospital. Clinical testing was performed on four subjects who underwent pedicled groin flap surgery. Reasonable signal quality was obtained from the last three cases. Errors and shortcomings from the first case were addressed and corrected where possible. Analysis of the recorded data coincided with standard clinical observations, indicating that the device was able to assist determining flap condition. Two of the three patients undergoing IP benefited from early flap division. Additional clinical tests could further prove the function and efficacy of the device, as well as improving post-testing data analysis methods.

AFRIKAANSE OPSOMMING: Weefselflappe speel `n integrale rol in plastiese en rekonstruktiewe chirurgie. Weefselflappe beskik oor eie bloedtoevoer en geskik vir die behandeling van wonde waarvoor veloorplantings onmoontlik is. Die monitering van weefselflappe is ’n belangrike praktyk omdat dit ‘n bydrae kan lewer aan weefseltoestand metings en aan die vroegtydig waarneming van bloedsomloopkomplikasies. Om komplikasies vroegtydig waar te neem is voordelig wanneer die velweefsel gered moet word. ’n Tegniek genaamd isgemiese prekondisie (IP) is as voordelig bewys vir die aanmoediging van vroeë weefselonthegting in die geval van pedikel-liesflappe. Tot dusver is IP in literatuur slegs met die hand toegepas terwyl ’n geoutomatiseerde prosedure pasiënte en mediese personeel sal bevoordeel, spesifiek in die Suid-Afrikaanse staatshospitaal-omgewing. ’n Toestel wat van pols-oksimetrie gebruik maak is ontwerp en ontwikkel om behulpsaam te wees met weefselflap-monitering en die analise van huidige IP-protokolle. Die toestel kan inligting moniteer en opneem, insluitend suurstof-saturasie (SpO2) en fotopletismogram (PPG), wat gemonitor is vanaf drie verskillende meetpunte. Die toestel is verder in staat om die IP-proses te outomatiseer deur die lugdruk in die knelverband te reguleer. Voordat kliniese toetse uitgevoer is, is die toestel aan verskeie toetse onderwerp, insluitend funksionaliteitstoetse wat aangedui het dat die toestel geskik is vir metings op gedeeltes van die liggaam wat relevant tot weefselflappe is. Toetse het aangedui dat die toestel nie beperk behoort te word tot die monitering van ’n enkele weefselflaptipe nie. Die volledige toestel is oorhandig aan ’n plastiese- rekonstruktiewe chirurg wat dit by die Chris Hani Baragwanath-hospitaal aan kliniese toetsing onderwerp het. Kliniese toetse is uitgevoer op vier pasiënte wat pedikel-liesflapchirurgie ondergaan het. ’n Redelike seinkwaliteit is verwerf in die laaste drie gevalle. Foute en tekortkominge tydens die eerste geval is aangespreek en reggestel waar moontlik. ’n Analise van aangetekende data het saamgeval met gestandaardiseerde kliniese waarnemings, wat aangedui het dat die toestel in staat is om te help met die monitering van weefselflaptoestande. Twee van die drie pasiënte wat IP ondergaan het, het by die monitering van vroeë weefselonthegting baat gevind. Addisionele kliniese toetse kan die funksionaliteit en doeltreffendheid van die toestel, sowel as post-toetsing data-analise, verder verbeter.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/98792
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