Automatic Smoke Analysis in Minimally Invasive Surgery by Image-Based Machine Learning

INTRODUCTION

Minimally Invasive Surgery uses electrosurgical tools that generate smoke. This smoke reduces the visibility of the surgical site and spreads harmful substances with potential hazards for the surgical staff. Automatic image analysis may provide assistance. However, the existing studies are restricted to simple clear versus smoky image classification.

MATERIALS AND METHODS

We propose a novel approach using surgical image analysis with machine learning, including deep neural networks. We address three tasks: 1) smoke quantification, which estimates the visual level of smoke, 2) smoke evacuation confidence, which estimates the level of confidence to evacuate smoke, and 3) smoke evacuation recommendation, which estimates the evacuation decision. We collected three datasets with expert annotations. We trained end-to-end neural networks for the three tasks. We also created indirect predictors using task 1 followed by linear regression to solve task 2 and using task 2 followed by binary classification to solve task 3.

RESULTS

We observe a reasonable inter-expert variability for tasks 1 and a large one for tasks 2 and 3. For task 1, the expert error is 17.61 percentage points (pp) and the neural network error is 18.45 pp. For tasks 2, the best results are obtained from the indirect predictor based on task 1. For this task, the expert error is 27.35 pp and the predictor error is 23.60 pp. For task 3, the expert accuracy is 76.78% and the predictor accuracy is 81.30%.

CONCLUSIONS

Smoke quantification, evacuation confidence, and evaluation recommendation can be achieved by automatic surgical image analysis with similar or better accuracy as the experts.

Demarcating Z-line and Gastric Folds Boundary Based on the Segmentation of the Lower Esophageal Sphincter Images

Background and Objective

The endoscopic diagnosis of pathological changes in the gastroesophageal junction including esophagitis and Barrett's mucosa is based on the visual detection of two boundaries: mucosal color change between esophagus and stomach, and top endpoint of gastric folds. The presence and pattern of mucosal breaks in the gastroesophageal mucosal junction (Z line) classify esophagitis in patients and the distance between the two boundaries points to the possible columnar lined epithelium. Since visual detection may suffer from intra- and interobserver variability, our objective was to define the boundaries automatically based on image processing algorithms, which may enable us to measure the detentions of changes in future studies.

Methods

To demarcate the Z-line, first the artifacts of endoscopy images are eliminated. In the second step, using SUSAN edge detector, Mahalanobis distance criteria, and Gabor filter bank, an initial contour is estimated for the Z-line. Using region-based active contours, this initial contour converges to the Z-line. Finally, by applying morphological operators and Gabor Filter Bank to the region inside of the Z-line, gastric folds are segmented.

Results

To evaluate the results, a database consisting of 50 images and their ground truths were collected. The average dice coefficient and mean square error of Z-line segmentation were 0.93 and 3.3, respectively. Furthermore, the average boundary distance criteria are 12.3 pixels. In addition, two other criteria that compare the segmentation of folds with several ground truths, i.e., Sweet-Spot Coverage and Jaccard Index for Golden Standard, are 0.90 and 0.84, respectively.

Conclusions

Considering the results, automatic segmentation of Z-line and gastric folds are matched to the ground truths with appropriate accuracy.

An Android Application for Estimating Muscle Onset Latency using Surface EMG Signal

BACKGROUND

Electromyography (EMG) signal processing and Muscle Onset Latency (MOL) are widely used in rehabilitation sciences and nerve conduction studies. The majority of existing software packages provided for estimating MOL via analyzing EMG signal are computerized, desktop based and not portable; therefore, experiments and signal analyzes using them should be completed locally. Moreover, a desktop or laptop is required to complete experiments using these packages, which costs.

OBJECTIVE

Develop a non-expensive and portable Android application (app) for estimating MOL via analyzing surface EMG.

MATERIAL AND METHODS

A multi-layer architecture model was designed for implementing the MOL estimation app. Several Android-based algorithms for analyzing a recorded EMG signal and estimating MOL was implemented. A graphical user interface (GUI) that simplifies analyzing a given EMG signal using the presented app was developed too.

RESULTS

Evaluation results of the developed app using 10 EMG signals showed promising performance; the MOL values estimated using the presented app are statistically equal to those estimated using a commercial Windows-based surface EMG analysis software (MegaWin 3.0). For the majority of cases relative error <10%. MOL values estimated by these two systems are linearly related, the correlation coefficient value ~ 0.93. These evaluations revealed that the presented app performed as well as MegaWin 3.0 software in estimating MOL.

CONCLUSION

Recent advances in smart portable devices such as mobile phones have shown the great capability of facilitating and decreasing the cost of analyzing biomedical signals, particularly in academic environments. Here, we developed an Android app for estimating MOL via analyzing the surface EMG signal. Performance is promising to use the app for teaching or research purposes.

3,7,10,14,15-pentaacetyl-5-butanoyl-13,17-epoxy-8-myrsinene a novel compound isolated from Pycnocycla spinosa extract with potent anti-spasmodic and antidiarrheal properties

Bioassay monitoring of hydroalcoholic extract from the aerial part of Pyconcycla spinosa revealed that it contains components with spasmolytic activity in vitro. In addition, P. spinosa extract at oral dose of 1-5 mg/kg inhibits diarrhoea in animal models. Pharmacological screening of pure compounds isolated from P. spinosa hydroalcoholic extract led to the identification of 3,7,10,14,15-pentaacetyl-5-butanoyl-13,17-epoxy-8-myrsinene (PABEM) which is a new diterpene. In this research, we have investigated antispasmodic and antidiarrheal effects of PABEM for comparison with P. spinosa extract. Aerial parts of P. spinosa were extracted with ethanol. For antispasmodic studies, rat isolated ileum was suspended in Tyrode's solution in an organ bath. The ileum was contracted by acetylcholine (ACh, 0.5 μM), serotonin (5-HT, 5 μM) or electrical field stimulation (EFS). P. spinosa extract in a concentration dependent manner (10-640 μg/ml) inhibited ileum contractions induced by ACh, 5-HT or EFS. The new compound isolated form P. spinosa extract "PABEM" in a similar manner inhibited the contractile response to ACh, 5-HT and EFS. However, the inhibitory effects of PABEM were observed at much lower bath concentrations. The relaxation effect of PABEM was started at 40 ng/ml bath concentration and with 2.5 μg/ml PABEM in the bath, the contractile responses of ileum were completely abolished. Both hydroalcoholic extract of P. spinosa and PABEM reduced intestinal meal transit and castor oil and MgSO4 induced diarrhoea in mice. However, PABEM was about 10 times more potent than its parent extract. This research shows that PABEM is probably the main component responsible for antispasmodic and antidiarrheal actions of P. spinosa extract.

Neutrophil function (innate immunity) during Ramadan

BACKGROUND

Fasting during the month of Ramadan is one of the essential religious practices of Muslims. The aim of this study was to evaluate opsonisation, phagocytosis, and nitroblue tetrazolium (NBT) reduction by white blood cells in normal, healthy, male subjects under non-fasting (before Ramadan) and fasting (after Ramadan) conditions.

METHODS

In this study, 13 Muslim men, aged 28-54 years, whose health was confirmed by health application forms, gave blood samples one week before the beginning of the holy month of Ramadan and during the last week of Ramadan. Blood samples were tested for neutrophil phagocytosis, serum opsonisation power, and NBT reduction.

RESULTS

Despite a decline in the neutrophil phagocytic index and serum opsonisation index, the percentage of neutrophils participating in phagocytosis increased with fasting. In addition, there was an increase in the percentage of neutrophils demonstrating NBT reduction. Although there was a decrease in opsonisation of the serum, the increased percentage of opsonisation compensated for this defect.

CONCLUSION

This study demonstrates the beneficial effect of fasting during Ramadan on neutrophil phagocytic function.

CYP2C9 gene analysis of some Iranian hypersensitive patients to warfarin

For the first time in this study, the pharmacogenetic effects of CYP2C9 polymorphism on warfarin sensitivity in some Iranian patients who are on warfarin treatment were shown. The study group consisted of clinically sensitive patients (21 patients) and the control group (37 adult patients). For detection of CYP2C9*2 and CYP2C9*3 variants, a protocol based on restriction fragment length polymorphism based polymerase chain reaction with Eco47I and KpnI was used. In clinically sensitive patients about 81% and in normal response patients about 24.3% carried variant genotypes.

Effect of Ramadan on neutrophil's respiratory burst (innate immunity) and circulating immune complex

BACKGROUND

The aim of this study was to investigate the effects of Ramadan fasting on neutrophil's respiratory burst and circulating immune complex (CIC) level.

METHODS

The effects of Ramadan fasting on neutrophil's respiratory burst and CIC was studied in 21 normal young fasting Muslim individuals using standardized chemiluminescence and poly ethylene glycol methods respectively, the results obtained and statistically analysed.

RESULTS

It was shown that in 11 cases out of 21 (52%) both of the chemiluminescence (CL) activity and CIC levels measured before and after Ramadan fasting were in normal range in spite of a insignificant decrease or increase in CL activity or CIC level. Therefore, the changes of the immunological parameters were not significant and the levels remained in the range of normal. In four cases out of 21 (24%), the CL activity and CIC levels were higher than normal range measured just before Ramadan, however after month of Ramadan the CL activity and CIC level decreased reaching to the normal level of these parameters. In four cases out of 21 (24%) there were an increase in CL activity and CIC levels after Ramadan fasting.

CONCLUSION

There were no significant changes of CL activity of circulating neutrophils and CIC levels comparing the results obtained before and after Ramadan. More over there was a good correlation between these two immunological parameters measured in the present study.

Assaying of warfarin in Iranian warfarin resistance patients blood by HPLC

A simple and rapid HPLC method with UV detecting system has been used in determination of warfarin level in plasma of Iranian patients who received different doses of this drug. Six resistance (10-70 mg day(-1)) and 5 sensitive patients (0.5-2.5 mg day(-1)) were selected for this study. Range of warfarin level in plasma was between 0.93 and 22.8. After determination of warfarin level in warfarin sensitive and especially, warfarin resistance patients, we are going to find a relationship between this level and pharmacokinetic or pharmacogenetic factors. In the separate study which was done in our laboratory on the gene that is possibly responsible for warfarin resistance we did not find any mutation in our patient with high warfarin concentration in their blood.

Presentation and pattern of symptoms in 382 patients with Glanzmann thrombasthenia in Iran

Glanzmann thrombasthenia (GT) is a rare autosomal recessive disease characterized by prolonged bleeding time with normal platelet count and morphology. It is caused by the quantitative or qualitative deficiency of the platelet glycoprotein IIb-IIIa. In 382 Iranian patients with GT diagnosed at a single center during the period 1969-2001, consanguinity between parents was 86.6%, in accord with the high frequency of intrafamilial marriages in Iran. Almost all patients had had abnormal mucocutaneous bleeding (epistaxis and gum bleeding); at follow-up, 4/5 of the patients had been transfused at least once to control hemorrhagic episodes. As expected, almost all the patients had a normal platelet count while the leukocyte count was increased in 19.3%. Among women, an unexpected low rate of pregnancies was observed.

Symptoms of inherited factor V deficiency in 35 Iranian patients

The type of bleeding symptom has been evaluated in 35 Iranian patients with an inherited deficiency of factor V, with plasma levels between 1% and 10%. The most frequent symptoms included epistaxis and excessive bleeding after surgery. Haemarthroses and muscle haematomas were less common, even in severely deficient patients. More severe symptoms such as gastrointestinal and central nervous system bleeding were rare. The severity of bleeding symptoms was only partially related to the degree of factor V deficiency in plasma. On the whole, human factor V deficiency is characterized by a moderately severe bleeding phenotype.

Congenital factor X deficiency: spectrum of bleeding symptoms in 32 Iranian patients

The spectrum of the clinical manifestations of congenital factor X deficiency was studied in 32 Iranian patients. The most frequent symptom was epistaxis, which occurred in 72% of patients, with all degrees of deficiency. Other mucosal haemorrhages (e.g. haematuria, gastrointestinal bleeding) were less frequent and occurred mainly in patients with unmeasurable factor X. Menorrhagia occurred in half of the women of reproductive age. Soft tissue bleeding occurred in two-thirds of the patients; spontaneous haematomas and haemarthroses led to severe arthropathy in five patients. Bleeding from the umbilical stump was an unexpected finding in nine patients. This study demonstrated that the bleeding tendency of factor X deficiency is severe and correlates with factor levels.

Clinical manifestations in 28 Italian and Iranian patients with severe factor VII deficiency

There has been wide variation in the reported haemorrhagic manifestations of factor VII deficiency. We examined type and frequency of clinical manifestations in 28 Iranian and Italian patients with severe deficiency (factor VII coagulant activity 2% or less). The most frequent symptoms were epistaxis and menorrhagia, whereas soft tissue bleeding such as haemarthrosis and muscle haematoma was less frequent. Only 5 of 9 patient who underwent surgery without factor VII replacement therapy had postoperative bleeding severe enough to require blood transfusion. No thrombotic manifestation occurred. A factor VII functional assay based on the use of human thromboplastin was a better predictor of the bleeding tendency of these patients than a rabbit thromboplastin-based functional assay or immunoassay. On the whole, this study shows that in severe factor VII deficiency bleeding in mucosal tracts is not uncommon. Surgery can sometimes be performed without replacement therapy and without haemorrhagic complications.