Development of an augmented reality guidance system for head and neck cancer resection.

The use of head-mounted augmented reality (AR) for surgeries has grown rapidly in recent years. AR aids in intraoperative surgical navigation through overlaying three-dimensional (3D) holographic reconstructions of medical data. However, performing AR surgeries on complex areas such as the head and neck region poses challenges in terms of accuracy and speed. This study explores the feasibility of an AR guidance system for resections of positive tumour margins in a cadaveric specimen. The authors present an intraoperative solution that enables surgeons to upload and visualize holographic reconstructions of resected cadaver tissues. The solution involves using a 3D scanner to capture detailed scans of the resected tissue, which are subsequently uploaded into our software. The software converts the scans of resected tissues into specimen holograms that are viewable through a head-mounted AR display. By re-aligning these holograms with cadavers with gestures or voice commands, surgeons can navigate the head and neck tumour site. This workflow can run concurrently with frozen section analysis. On average, the authors achieve an uploading time of 2.98 min, visualization time of 1.05 min, and re-alignment time of 4.39 min, compared to the 20 to 30 min typical for frozen section analysis. The authors achieve a mean re-alignment error of 3.1 mm. The authors' software provides a foundation for new research and product development for using AR to navigate complex 3D anatomy in surgery.

Non-targeted detection of paprika adulteration using mid-infrared spectroscopy and one-class classification - Is it data preprocessing that makes the performance?

A method for the non-targeted detection of paprika adulteration was developed using Fourier transform mid-infrared (FT-MIR) spectroscopy and one-class soft independent modelling of class analogy (OCSIMCA). One-class models based on commercially available paprika powders were developed and optimised to provide >80% sensitivity by external validation. The performances of the established models for adulteration detection were tested by predicting spiked paprika samples with various types of fraudulent material and levels of adulterations including 1% (w/w) Sudan I, 1% (w/w) Sudan IV, 3% (w/w) lead chromate, 3% (w/w) lead oxide, 5% (w/w) silicon dioxide, 10% (w/w) polyvinyl chloride, and 10% (w/w) gum arabic. Further, the influence of data preprocessing on the model performance was investigated. Relationship between classification results and data preprocessing was identified and specificity >80% was achieved for all adulterants by applying different preprocessing methods including standard normal variate (SNV), first and second derivatives, smoothing, and combinations thereof.

Screening for sulfate in distillers dried grains and solubles by FT-IR spectroscopy.

Distillers Dried Grains and Solubles (DDGS) are an animal feed containing varying levels of sulfur. As ruminants are susceptible to high sulfur diets, sulfur content is of major interest to the parties involved. The variation in levels of sulfur in DDGS is mainly due to sulfate derived from the addition of sulfuric acid during the production. ATR/FT-IR spectroscopy was used to determine sulfate levels in 90 DDGS samples from various origins (Canada, China, EU, and U.S.A.). Specific absorption bands for sulfate at 615 and 1107 cm(-1) enabled the analysis of sulfate in the DDGS matrix. Besides direct quantification (using band at 615 cm(-1)), PLS regression was applied for the prediction of sulfate using FT-IR spectra and calibration with reference values analyzed by capillary electrophoresis. An extended calculation on the total sulfur estimated that 11% of the DDGS samples analyzed in this study featured sulfur contents higher than 0.80%.

An evaluation of commonly employed central venous catheter kits and their potential risk for complications of excess guidewire introduction.

STUDY OBJECTIVE: To evaluate the components of commonly used central venous catheter kits with respect to the potential for guidewire-mediated complications during catheter placement.Prospective, nonrandomized, observational study. SETTING: Six academic hospitals across the United States. PATIENTS: None. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: 30 commercially manufactured catheter kits (15 tunneled, 15 nontunneled) were opened and evaluated. The catheter or sheath to be introduced was measured and a corresponding ideal guidewire length was calculated. The ideal length was then compared to the actual length, and differences were tabulated. Wire tip configuration and the presence and pattern of distance markings were recorded and, in conjunction with the catheter and wire length discrepancies, were used to grade the relative risk of introducing excess guidewire during catheter placement. Of 30 kits evaluated, 14 (46.7%) had guidewires more than 20 cm longer than necessary. The mean excess wire length was 15 cm (range: 8 to 55 cm) and did not differ significantly between tunneled and nontunneled catheter kits. Only 10 kits (33.3%) had distance markings of any type, and there was no standardization among them; none corresponded to previously published recommendations. There was potential risk of excess wire introduction in 18 catheter kits, of which seven were nontunneled devices designed for bedside placement. CONCLUSIONS: The design of commonly employed central venous access catheter kits is such that there is a mismatch between guidewire and catheter length and a general lack of guidewire markings. We believe that these designs may predispose to the introduction of excess guidewire and result in guidewire-mediated complications during catheter placement. This risk can likely be reduced by matching the guidewires to the devices placed over them and by standardizing guidewire distance markings.

Authentication of the botanical and geographical origin of distillers dried grains and solubles (DDGS) by FT-IR spectroscopy.

Distillers dried grains and solubles (DDGS) were investigated with attenuated total reflection FT-IR spectroscopy both directly in their solid state and as the isolated oils (fat fractions). The collected spectra were evaluated in a first step with principal component analysis (PCA) according to the botanical origin (corn, rice, wheat) and the geographical origin (Canada, China, European Union, India, United States) of the DDGS. In a second step, statistical models were constructed for the characterization of the botanical and geographical origin using linear discriminant analysis (LDA) and soft independent modeling of class analogy (SIMCA). For this purpose, the botanical origin was investigated more deeply for corn and wheat as the most important raw materials used for DDGS production. Also, the geographical origin was investigated exemplary for corn DDGS, derived from China and the United States. Models were validated by a randomized batchwise procedure and showed satisfactory classification rates, in most cases better than 80% correct classification.

Relative bioavailability of coumarin from cinnamon and cinnamon-containing foods compared to isolated coumarin: a four-way crossover study in human volunteers.

SCOPE: Cassia cinnamon contains high levels (up to 1 %) of coumarin. Heavy consumption of this spice may result in a dose exceeding the tolerable daily intake (TDI). In this context, the question was raised whether coumarin in the plant matrix of cinnamon has the same bioavailability as isolated coumarin. METHODS AND RESULTS: A four-way crossover study was performed, in which the same dose of 12 mg coumarin was administered in different formulations to 24 healthy volunteers. The relative extent of absorption measured as urinary excretion of the main metabolite 7-hydroxycoumarin (7OHC) was found to be 62.8% for isolated coumarin in a capsule (reference), 56.0% for cinnamon in capsules, 66.1% for cinnamon tea, and 54.7% for cinnamon in rice pudding (means, n=23, observation period 8 hours). Additionally, 7OHC plasma levels were measured for 105 minutes after administration and revealed a fast absorption of coumarin from cinnamon tea leading to the highest peak concentrations. CONCLUSION: The relative extent of absorption of coumarin from powder of cassia cinnamon is only slightly lower than that of isolated coumarin. Therefore, the TDI of coumarin can be used for risk assessment of coumarin exposure from cinnamon-containing meals.