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  1. Article ; Online: Grey-box modelling and fuzzy logic control of a Leader-Follower robot manipulator system: A hybrid Grey Wolf-Whale Optimisation approach.

    Obadina, Ololade O / Thaha, Mohamed A / Mohamed, Zaharuddin / Shaheed, M Hasan

    ISA transactions

    2022  Volume 129, Issue Pt B, Page(s) 572–593

    Abstract: This study presents the development of a grey-box modelling approach and fuzzy logic control for real time trajectory control of an experimental four degree-of-freedom Leader-Follower​ Robot (LFR) manipulator system using a hybrid optimisation algorithm, ...

    Abstract This study presents the development of a grey-box modelling approach and fuzzy logic control for real time trajectory control of an experimental four degree-of-freedom Leader-Follower​ Robot (LFR) manipulator system using a hybrid optimisation algorithm, known as Grey Wolf Optimiser (GWO) - Whale Optimisation Algorithm (WOA). The approach has advantages in achieving an accurate model of the LFR manipulator system, and together with a better trajectory tracking performance. In the first instance, the white box model is formed by modelling the dynamics of the follower manipulator using the Euler-Lagrange formulation. This white-box model is then improved upon by re-tuning the model's parameters using GWO-WOA and experimental data from the real LFR manipulator system, thus forming the grey-box model. A minimum improvement of 73.9% is achieved by the grey-box model in comparison to the white-box model. In the latter part of this investigation, the developed grey-box model is used for the design, tuning and real-time implementation of a fuzzy PD+I controller on the experimental LFR manipulator system. A 78% improvement in the total mean squared error is realised after tuning the membership functions of the fuzzy logic controller using GWO-WOA. Experimental results show that the approach significantly improves the trajectory tracking performance of the LFR manipulator system in terms of mean squared error, steady state error and time delay.
    MeSH term(s) Algorithms ; Animals ; Fuzzy Logic ; Robotics/methods ; Whales ; Wolves
    Language English
    Publishing date 2022-02-21
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2012746-7
    ISSN 1879-2022 ; 0019-0578
    ISSN (online) 1879-2022
    ISSN 0019-0578
    DOI 10.1016/j.isatra.2022.02.023
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  2. Article ; Online: In silico and in vivo investigations using an endocavitary photoplethysmography sensor for tissue viability monitoring.

    Chatterjee, Subhasri / Patel, Zaibaa / Thaha, Mohamed A / Kyriacou, Panayiotis A

    Journal of biomedical optics

    2020  Volume 25, Issue 2, Page(s) 1–16

    Abstract: Significance: Colorectal cancer is one of the major causes of cancer-related deaths worldwide. Surgical removal of the cancerous growth is the primary treatment for this disease. A colorectal cancer surgery, however, is often unsuccessful due to the ... ...

    Abstract Significance: Colorectal cancer is one of the major causes of cancer-related deaths worldwide. Surgical removal of the cancerous growth is the primary treatment for this disease. A colorectal cancer surgery, however, is often unsuccessful due to the anastomotic failure that may occur following the surgical incision. Prevention of an anastomotic failure requires continuous monitoring of intestinal tissue viability during and after colorectal surgery. To date, no clinical technology exists for the dynamic and continuous monitoring of the intestinal perfusion.
    Aim: A dual-wavelength indwelling bowel photoplethysmography (PPG) sensor for the continuous monitoring of intestinal viability was proposed and characterized through a set of in silico and in vivo investigations.
    Approach: The in silico investigation was based on a Monte Carlo model that was executed to quantify the variables such as penetration depth and detected intensity with respect to the sensor-tissue separations and tissue perfusion. Utilizing the simulated information, an indwelling reflectance PPG sensor was designed and tested on 20 healthy volunteers. Two sets of in vivo studies were performed using the driving current intensities 20 and 40 mA for a comparative analysis, using buccal tissue as a proxy tissue-site.
    Results: Both simulated and experimental results showed the efficacy of the sensor to acquire good signals through the "contact" to a "noncontact" separation of 5 mm. A very slow wavelength-dependent variation was shown in the detected intensity at the normal and hypoxic states of the tissue, whereas a decay in the intensity was found with the increasing submucosal-blood volume. The simulated detected-to-incident-photon-ratio and the experimental signal-to-noise ratio exhibited strong positive correlations, with the Pearson product-moment correlation coefficient R ranging between 0.65 and 0.87.
    Conclusions: The detailed feasibility analysis presented will lead to clinical trials utilizing the proposed sensor.
    MeSH term(s) Adolescent ; Adult ; Biosensing Techniques/instrumentation ; Equipment Design ; Female ; Humans ; Male ; Monitoring, Physiologic ; Monte Carlo Method ; Mouth Mucosa/blood supply ; Oxygen/blood ; Photoplethysmography/instrumentation ; Signal Processing, Computer-Assisted ; Signal-To-Noise Ratio ; Tissue Survival/physiology ; Young Adult
    Chemical Substances Oxygen (S88TT14065)
    Language English
    Publishing date 2020-01-30
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1309154-2
    ISSN 1560-2281 ; 1083-3668
    ISSN (online) 1560-2281
    ISSN 1083-3668
    DOI 10.1117/1.JBO.25.2.027001
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: The effects of optical sensor-tissue separation in endocavitary photoplethysmography.

    Patel, Zaibaa / Thaha, Mohamed A / Kyriacou, Panayiotis A

    Physiological measurement

    2018  Volume 39, Issue 7, Page(s) 75001

    Abstract: Objective: Intestinal anastomotic failure that occurs mainly due to ischaemia is a serious risk in colorectal cancer patients undergoing surgery. Surgeons continue to rely on subjective methods such as visual inspection to assess intestinal viability ... ...

    Abstract Objective: Intestinal anastomotic failure that occurs mainly due to ischaemia is a serious risk in colorectal cancer patients undergoing surgery. Surgeons continue to rely on subjective methods such as visual inspection to assess intestinal viability during surgery and there are no clinical tools to directly monitor viability postoperatively. A dual-wavelength reflectance optical sensor has been developed for continuous and dynamic monitoring of intestinal viability via the intestinal lumen. Maintaining direct contact between the sensor and the inner intestinal wall can be difficult in an intraluminal design, therefore impacting on signal acquisition and quality. This paper investigates the effect of direct contact versus variable distances between the sensor and the tissue surface of the buccal mucosa as a surrogate.
    Approach: The in vivo study involved 20 healthy volunteers to measure the effect of optical sensor-tissue distances on the ability to acquire photoplethysmography signals and their quality. Signals were acquired from the buccal mucosa at five optical sensor-tissue distances.
    Main results: Distances between 0 mm (contact) to 5 mm were the most optimal, producing signals of high quality and signal-to-noise ratio, resulting in reliable estimations of the blood oxygen saturation. Distances exceeding 5 mm compromised the acquired signals, and were of poor quality, thereby unreliably estimating the blood oxygen saturation.
    Significance: The developed optical sensor proved to be reliable for acquiring photoplethysmography signals for cases where distances between the optical sensor-tissue may arise during the assessment of intraluminal intestinal viability.
    MeSH term(s) Adolescent ; Adult ; Equipment Design ; Female ; Humans ; Male ; Mouth ; Mucous Membrane ; Optical Devices ; Photoplethysmography/instrumentation ; Signal Processing, Computer-Assisted ; Young Adult
    Language English
    Publishing date 2018-07-03
    Publishing country England
    Document type Journal Article
    ZDB-ID 1149545-5
    ISSN 1361-6579 ; 0967-3334
    ISSN (online) 1361-6579
    ISSN 0967-3334
    DOI 10.1088/1361-6579/aacc1d
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Development of an intraluminal intestinal photoplethysmography sensor.

    Patel, Zaibaa / Thaha, Mohamed A / Kyriacou, Panayiotis A

    Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference

    2017  Volume 2017, Page(s) 1840–1843

    Abstract: Intestinal ischemia is a serious medical condition and can lead to life threatening sepsis. Currently, there are no reliable techniques available for directly monitoring intestinal viability for prolonged periods of time, and intraoperatively, the ... ...

    Abstract Intestinal ischemia is a serious medical condition and can lead to life threatening sepsis. Currently, there are no reliable techniques available for directly monitoring intestinal viability for prolonged periods of time, and intraoperatively, the majority of the surgeons still rely on subjective methods, such as visual inspection to assess viability of the intestine. The development of an intraluminal optical sensor for monitoring intestinal viability is being proposed. The sensor will continuously monitor changes in blood volume and oxygen saturation. The developed reflectance photoplethysmography/pulse oximetry sensor comprises of two emitters (red and infrared) and a photodiode. A photoplethysmography processing and data acquisition system was also utilized. The prototype sensor was evaluated in a pilot study in the buccal mucosa of 12 healthy volunteers, given the locations similarity to the intestinal mucosa and its easy accessibility. Good quality photoplethysmography signals with high signal-to-noise ratio were acquired from the buccal mucosa in all the volunteers. Preliminary blood oxygen saturation values from the intraluminal sensor were in broad agreement with the standard finger pulse oximeter probes.
    MeSH term(s) Fingers ; Humans ; Intestines ; Oximetry ; Oxygen ; Photoplethysmography ; Pilot Projects
    Chemical Substances Oxygen (S88TT14065)
    Language English
    Publishing date 2017-10-20
    Publishing country United States
    Document type Journal Article
    ISSN 2694-0604
    ISSN (online) 2694-0604
    DOI 10.1109/EMBC.2017.8037204
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Reply letter to: A letter to the editor on "Anterior perineal plane for ultra-low anterior resection of the rectum (APPEAR) technique: A systematic review".

    Lynes, Kathryn / Williams, Norman S / Chan, Christopher L / Thaha, Mohamed A

    International journal of surgery (London, England)

    2018  Volume 62, Page(s) 87

    MeSH term(s) Humans ; Perineum ; Proctectomy ; Rectal Neoplasms ; Rectum
    Language English
    Publishing date 2018-12-13
    Publishing country England
    Document type Letter ; Comment
    ZDB-ID 2212038-5
    ISSN 1743-9159 ; 1743-9191
    ISSN (online) 1743-9159
    ISSN 1743-9191
    DOI 10.1016/j.ijsu.2018.12.005
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Anterior Perineal PlanE for ultra-low Anterior Resection of the rectum (APPEAR) technique: A systematic review.

    Lynes, Kathryn / Williams, Norman S / Chan, Christopher L / Thaha, Mohamed A

    International journal of surgery (London, England)

    2016  Volume 33 Pt A, Page(s) 117–123

    Abstract: Introduction: The Anterior Perineal PlanE for ultra-low Anterior Resection of the rectum (APPEAR) technique utilises a perineal incision to facilitate resection of the distal rectum. The aim of this study was to review use of the APPEAR technique, ... ...

    Abstract Introduction: The Anterior Perineal PlanE for ultra-low Anterior Resection of the rectum (APPEAR) technique utilises a perineal incision to facilitate resection of the distal rectum. The aim of this study was to review use of the APPEAR technique, assessing patient selection, indications, complications and outcomes, both oncological and functional.
    Materials and methods: A systematic review was carried out to identify studies reporting outcomes following rectal resection via an anterior perineal incision, with no limits on year or language. All studies were included. Quality of studies was assessed using the methodological index for non-randomised studies (MINORS) score.
    Results: Thirteen studies were identified from 1985 to 2013. 174 patients (102 male), ranging from 21 to 82 years, underwent surgery at eleven centres in seven countries. Maximum experience at one centre is 60 cases. 9 cases were performed for rectal dysplasia, 141 for rectal cancer; 96 resections were R0 (remaining 45 unstated). 14 cases were carried out laparoscopically. 30-day mortality was 2.3% (4 patients); there were 2 further deaths from systemic recurrence. Permanent stoma rate was 8/155 (5%). The most frequent complication was perineal or vaginal fistulation (26 patients): 6 underwent reoperation; 15 healed with conservative management; 5 required a permanent stoma. Functional outcomes were variably reported; median stool frequency was 3/24hrs with average Wexner scores of 5-5.5.
    Conclusion: In selected patients the APPEAR technique offers avoidance of permanent colostomy with good oncological outcomes. The majority of studies had short follow up periods and longer-term outcomes will need evaluation.
    MeSH term(s) Adult ; Aged ; Aged, 80 and over ; Colostomy ; Female ; Humans ; Laparoscopy ; Male ; Middle Aged ; Perineum/surgery ; Rectal Diseases/surgery ; Reoperation ; Surgical Stomas ; Treatment Outcome ; Young Adult
    Language English
    Publishing date 2016-08-05
    Publishing country England
    Document type Journal Article ; Review ; Systematic Review
    ZDB-ID 2212038-5
    ISSN 1743-9159 ; 1743-9191
    ISSN (online) 1743-9159
    ISSN 1743-9191
    DOI 10.1016/j.ijsu.2016.07.075
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  7. Article ; Online: Public appreciation of lifestyle risk factors for colorectal cancer and awareness of bowel cancer screening: A cross-sectional study.

    Lynes, Kathryn / Kazmi, Sahar A / Robery, Jordan D / Wong, Simon / Gilbert, Deborah / Thaha, Mohamed A

    International journal of surgery (London, England)

    2016  Volume 36, Issue Pt A, Page(s) 312–318

    Abstract: Introduction: Prevention of colorectal cancer (CRC) via reduction of lifestyle risk factors, and participation in bowel screening are two ways in which public engagement could lower mortality from colorectal cancer. This study examined public awareness ... ...

    Abstract Introduction: Prevention of colorectal cancer (CRC) via reduction of lifestyle risk factors, and participation in bowel screening are two ways in which public engagement could lower mortality from colorectal cancer. This study examined public awareness of lifestyle risk factors and bowel screening, with determination of the factors affecting this.
    Methods: A representative population sample (n = 1969) was surveyed using a study specific postal questionnaire to determine demographics, experience of bowel problems, awareness of lifestyle risk factors, knowledge about the incidence of CRC and potential benefits of screening, as well as personal experience of screening.
    Results: The majority of respondents were aged over 50 (74%). 77% had either personal experience or a relative/friend with experience of a bowel problem. Knowledge of dietary advice was better than risks relating to weight and physical activity. Awareness of lifestyle risk factors was significantly worse in those less than 50 years old (p = 0.0004) and with a lower level of education (p = 0.0021). Awareness of bowel cancer diagnosis was significantly lower in those less than 50 years old (p=<0.0001). The most frequent reason for non-completion of a screening kit was that the process was dirty and unpleasant.
    Conclusion: Initiatives are required to improve awareness of younger people with regard to lifestyle risk factors for CRC, especially since this group stand to benefit most from risk reduction. Those with a lower educational level also had poor awareness but felt that the NHS should not prescribe exercise and lifestyle change; targeting this group would need to take this into account.
    MeSH term(s) Adolescent ; Adult ; Aged ; Colorectal Neoplasms/diagnosis ; Colorectal Neoplasms/etiology ; Cross-Sectional Studies ; Early Detection of Cancer ; Female ; Humans ; Life Style ; Male ; Middle Aged ; Risk Factors
    Language English
    Publishing date 2016-12
    Publishing country England
    Document type Journal Article
    ZDB-ID 2212038-5
    ISSN 1743-9159 ; 1743-9191
    ISSN (online) 1743-9159
    ISSN 1743-9191
    DOI 10.1016/j.ijsu.2016.11.002
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  8. Article ; Online: Splenic parenchymal complications in pancreatitis.

    Patil, Pradeep V / Khalil, Ahmed / Thaha, Mohamed A

    JOP : Journal of the pancreas

    2011  Volume 12, Issue 3, Page(s) 287–291

    Abstract: Context: The close proximity of splenic hilum to the tail of pancreas makes it vulnerable to complications in both acute and chronic pancreatitis. In this article, we examine the clinical course of these potentially fatal complications.: Case reports!# ...

    Abstract Context: The close proximity of splenic hilum to the tail of pancreas makes it vulnerable to complications in both acute and chronic pancreatitis. In this article, we examine the clinical course of these potentially fatal complications.
    Case reports: Citing three clinical cases, we present the spectrum of splenic complications in pancreatitis and explore the anatomical causal relationships and pathological basis of such complications. A literature review was carried out to inform on the incidence, morbidity and mortality rates, and clinical course especially diagnostic and management options for these patients. The spectrum of splenic complications in pancreatitis is wide ranging from pseudo cysts to haematomas, haemorrhages, infarctions and life threatening splenic rupture. Although a contrast enhanced helical CT scan is the investigation of choice a high index of clinical suspicion is essential in their early identification. Splenic complications in pancreatitis incur a high morbidity (79%) and a significant mortality (8%).
    Conclusions: Splenic parenchymal complications in pancreatitis are an increasingly recognised entity and should be suspected in patients with inflammation and or necrosis involving the tail of pancreas. Conservative management is feasible with close radiological monitoring for most patients in a tertiary referral centre with appropriate expertise and surgery may be reserved for haemodynamically unstable patients.
    MeSH term(s) Female ; Hematoma/diagnosis ; Hematoma/etiology ; Hematoma/surgery ; Humans ; Male ; Middle Aged ; Pancreatic Pseudocyst/complications ; Pancreatitis/complications ; Spleen/diagnostic imaging ; Spleen/surgery ; Splenic Diseases/diagnosis ; Splenic Diseases/etiology ; Splenic Diseases/surgery ; Tomography, X-Ray Computed ; Treatment Outcome ; Young Adult
    Language English
    Publishing date 2011-05-06
    Publishing country Italy
    Document type Case Reports ; Journal Article
    ZDB-ID 2039637-5
    ISSN 1590-8577 ; 1590-8577
    ISSN (online) 1590-8577
    ISSN 1590-8577
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  9. Article ; Online: Sacral nerve stimulation for faecal incontinence and constipation in adults.

    Thaha, Mohamed A / Abukar, Amin A / Thin, Noel N / Ramsanahie, Anthony / Knowles, Charles H

    The Cochrane database of systematic reviews

    2015  , Issue 8, Page(s) CD004464

    Abstract: Background: Faecal incontinence (FI) and constipation are both socially-embarrassing and physically-disabling conditions that impair quality of life. For both, surgery may be required in a minority of people when more conservative measures fail. However, ...

    Abstract Background: Faecal incontinence (FI) and constipation are both socially-embarrassing and physically-disabling conditions that impair quality of life. For both, surgery may be required in a minority of people when more conservative measures fail. However, the invasiveness and irreversible nature of direct surgery on bowel and sphincter muscles, poor long-term outcomes and well-established compIications makes such procedures unappealing for these benign conditions. A less-invasive surgical option to treat faecal incontinence and constipation is direct, low-voltage stimulation of the sacral nerve roots, termed sacral nerve stimulation (SNS). SNS has become the first line surgical treatment for FI in people failing conservative therapies. Its value in the treatment of constipation is less clear.
    Objectives: To assess the effects of sacral nerve stimulation using implanted electrodes for the treatment of faecal incontinence and constipation in adults.
    Search methods: We searched the Cochrane Incontinence Group Specialised Register, which contains trials identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, MEDLINE In-Process, ClinicalTrials.gov, the World Health Organization (WHO) ICTRP and handsearched journals and conference proceedings (searched 5 February 2015), EMBASE (1 January 1947 to 2015 Week 5), and the reference lists of retrieved relevant articles.
    Selection criteria: All randomised or quasi-randomised trials assessing the effects of SNS for faecal incontinence or constipation in adults.
    Data collection and analysis: Two review authors independently screened the search results, assessed the methodological quality of the included trials, and undertook data extraction.
    Main results: Six crossover trials and two parallel group trials were included.Six trials assessed the effects of SNS for FI. In the parallel group trial conducted by Tjandra, 53 participants with severe FI in the SNS group experienced fewer episodes of faecal incontinence compared to the control group who received optimal medical therapy (mean difference (MD) -5.20, 95% confidence interval (CI) -9.15 to -1.25 at 3 months; MD -6.30, 95% CI -10.34 to -2.26 at 12 months). Adverse events were reported in a proportion of participants: pain at implant site (6%), seroma (2%) and excessive tingling in the vaginal region (9%).In the parallel group trial carried out by Thin, 15 participants with FI in the SNS group experienced fewer episodes of FI compared with the percutaneous tibial nerve stimulation (PTNS) group (MD -3.00, 95% CI -6.61 to 0.61 at 3 months; MD -3.20, 95% CI -7.14 to 0.74 at 12 months). Adverse events were reported in three participants: mild ipsilateral leg pain during temporary testing (n = 1); and stimulator-site pain following insertion of neurostimulator (n = 2).In the crossover trial by Leroi 7 of 34 recruited participants were excluded from the crossover due mainly to complications or immediate device failure. Twenty-four of the remaining 27 participants while still blinded chose the period of stimulation they had preferred. Outcomes were reported separately for 19 participants who preferred the 'on' and five who preferred the 'off' period. For the group of 19, the median (range) episodes of faecal incontinence per week fell from 1.7 (0 to 9) during the 'off' period to 0.7 (0 to 5) during the 'on' period; for the group of five, however, the median (range) rose from 1.7 (0 to 11) during the 'off' period compared with 3.7 (0 to 11) during the 'on' period. Four of 27 participants experienced an adverse event resulting in removal of the stimulator.In the crossover trial by Sørensen and colleagues, participants did not experience any FI episodes in either the one-week 'on' or 'off' periods.In the crossover trial by Vaizey, participants reported an average of six, and one, episodes of faecal incontinence per week during the 'off' and 'on' periods respectively in two participants with FI. Neither study reported adverse events.In the crossover trial by Kahlke, 14 participants with FI experienced significantly lower episodes of FI per week during the stimulator 'on' (1 (SD, 1.7)) compared with the 'off' period (8.4 (SD, 8.7)). Adverse events reported include: haematoma formation (n = 3); misplacement of tined lead (1); and pain at stimulator site (n = 1).Two trials assessed SNS for constipation. In the Kenefick trial, the two participants experienced an average of two bowel movements per week during the 'off' crossover period, compared with five during the 'on' period. Abdominal pain and bloating occurred 79% of the time during the 'off' period compared with 33% during the 'on' period. No adverse events occurred. In contrast, in the trial by Dinning with 59 participants, SNS did not improve frequency of bowel movements and 73 adverse events were reported, which included pain at site of the implanted pulse generator (32), wound infection (12), and urological (17) events.
    Authors' conclusions: The limited evidence from the included trials suggests that SNS can improve continence in a proportion of patients with faecal incontinence. However, SNS did not improve symptoms in patients with constipation. In addition, adverse events occurred in some patients where these were reported. Rigorous high quality randomised trials are needed to allow the effects of SNS for these conditions to be assessed with more certainty.
    MeSH term(s) Adult ; Constipation/therapy ; Cross-Over Studies ; Electric Stimulation Therapy/adverse effects ; Electric Stimulation Therapy/methods ; Electrodes, Implanted/adverse effects ; Fecal Incontinence/therapy ; Female ; Humans ; Male ; Outcome Assessment, Health Care ; Randomized Controlled Trials as Topic ; Sacrum ; Spinal Nerves
    Language English
    Publishing date 2015-08-24
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Review ; Systematic Review
    ISSN 1469-493X
    ISSN (online) 1469-493X
    DOI 10.1002/14651858.CD004464.pub3
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Intraoperative monitoring of intestinal viability: Evaluation of a new combined sensor.

    McGuinness-Abdollahi, Zahra / Thaha, Mohamed A / Ramsanahie, Anthony / Ahmed, Shafi / Kyriacou, Panayiotis A / Phillips, Justin P

    Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference

    2016  Volume 2015, Page(s) 5126–5129

    Abstract: A dual wavelength photoplethysmography (PPG) and laser Doppler flowmetry (LDF) sensor was developed to investigate the suitability of these techniques for monitoring bowel viability intraoperatively. Clinical measurements were obtained from thirty ... ...

    Abstract A dual wavelength photoplethysmography (PPG) and laser Doppler flowmetry (LDF) sensor was developed to investigate the suitability of these techniques for monitoring bowel viability intraoperatively. Clinical measurements were obtained from thirty patients undergoing bowel surgery. Three measurements were performed at different stages of the operation. The amplitude of infrared PPG decreased from the baseline measurement to the pre-anastomosis measurement by 36% and LDF flux decreased by 21% for the same measurements. An increase of 33% in amplitude for infrared PPG was observed from the pre-anastomotic to post-anastomosis measurement; the equivalent increase was not seen for LDF flux. The results revealed that the sensor could potentially indicate changes in perfusion and blood flow at critical phases of surgery, thereby assisting in the early detection of inadequate blood supply in bowel tissue. The results also suggest that laser Doppler is more sensitive to movement artefact compared to PPG.
    MeSH term(s) Adult ; Aged ; Aged, 80 and over ; Anastomosis, Surgical ; Digestive System Surgical Procedures/adverse effects ; Digestive System Surgical Procedures/methods ; Equipment Design ; Humans ; Intestines/blood supply ; Intestines/surgery ; Laser-Doppler Flowmetry/instrumentation ; Laser-Doppler Flowmetry/methods ; Middle Aged ; Monitoring, Intraoperative/instrumentation ; Monitoring, Intraoperative/methods ; Photoplethysmography/instrumentation ; Photoplethysmography/methods ; Prospective Studies
    Language English
    Publishing date 2016-01-12
    Publishing country United States
    Document type Journal Article
    ISSN 2694-0604
    ISSN (online) 2694-0604
    DOI 10.1109/EMBC.2015.7319545
    Database MEDical Literature Analysis and Retrieval System OnLINE

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