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Background: Cancer is a leading cause of death worldwide. While routine diagnosis of cancer is performed mainly with biopsy sampling, it is suboptimal to accurately characterize tumor heterogeneity. Positron emission tomography (PET)-driven radiomic research has demonstrated promising results when predicting clinical endpoints. This study aimed to investigate the added value of quantum machine learning both in simulator and in real quantum computers utilizing error mitigation techniques to predict clinical endpoints in various PET cancer patients. Methods: Previously published PET radiomics datasets including 11C-MET PET glioma, 68GA-PSMA-11 PET prostate and lung 18F-FDG PET with 3-year survival, low-vs-high Gleason risk and 2-year survival as clinical endpoints respectively were utilized in this study. Redundancy reduction with 0.7, 0.8, and 0.9 Spearman rank thresholds (SRT), followed by selecting 8 and 16 features from all cohorts, was performed, resulting in 18 dataset variants. Quantum advantage was estimated by Geometric Difference (GDQ) score in each dataset variant. Five classic machine learning (CML) and their quantum versions (QML) were trained and tested in simulator environments across the dataset variants. Quantum circuit optimization and error mitigation were performed, followed by training and testing selected QML methods on the 21-qubit IonQ Aria quantum computer. Predictive performances were estimated by test balanced accuracy (BACC) values. Results: On average, QML outperformed CML in simulator environments with 16-features (BACC 70% and 69%, respectively), while with 8-features, CML outperformed QML with + 1%. The highest average QML advantage was + 4%. The GDQ scores were ≤ 1.0 in all the 8-feature cases, while they were > 1.0 when QML outperformed CML in 9 out of 11 cases. The test BACC of selected QML methods and datasets in the IonQ device without error mitigation (EM) were 69.94% BACC, while EM increased test BACC to 75.66% (76.77% in noiseless simulators). Conclusions: We demonstrated that with error mitigation, quantum advantage can be achieved in real existing quantum computers when predicting clinical endpoints in clinically relevant PET cancer cohorts. Quantum advantage can already be achieved in simulator environments in these cohorts when relying on QML. [ABSTRACT FROM AUTHOR]

Quantum machine learning has experienced significant progress in both software and hardware development in the recent years and has emerged as an applicable area of near-term quantum computers. In this work, we investigate the feasibility of utilizing quantum machine learning (QML) on real clinical datasets. We propose two QML algorithms for data classification on IBM quantum hardware: a quantum distance classifier (qDS) and a simplified quantum-kernel support vector machine (sqKSVM). We utilize these different methods using the linear time quantum data encoding technique ( log 2 N ) for embedding classical data into quantum states and estimating the inner product on the 15-qubit IBMQ Melbourne quantum computer. We match the predictive performance of our QML approaches with prior QML methods and with their classical counterpart algorithms for three open-access clinical datasets. Our results imply that the qDS in small sample and feature count datasets outperforms kernel-based methods. In contrast, quantum kernel approaches outperform qDS in high sample and feature count datasets. We demonstrate that the log 2 N encoding increases predictive performance with up to + 2% area under the receiver operator characteristics curve across all quantum machine learning approaches, thus, making it ideal for machine learning tasks executed in Noisy Intermediate Scale Quantum computers. [ABSTRACT FROM AUTHOR]

The disease activity score of 28 joints (DAS28) is now commonly used for the guidance of treatment decisions in rheumatoid arthritis (RA). The goal of this work was to determine whether patients with DAS28 > 3.2 but less than 2 swollen and 2 tender joints respond differently to treatment than patients with a higher number of active joints. One hundred and ninety two patients with active RA treated in a rheumatology hospital as in-patients were studied prospectively. At admission (T1), release (T2) and 3 months after release (T3) disease activity (DAS28-CRP at T1 + 2, RADAI at T1 + 3), pain (numeric scale at T1 − 3) and function (FFbH at T1 + 3) were measured. A total of 148 patients had two or more (group 1) and 44 less than 2 swollen and tender joints at admission (group 2) but both groups had similar over all DAS28-scores. The groups significantly differed in their outcome after 3 months: group 1 had a significant better reduction of disease activity, pain and functional deficit ( p < 0.001 for the fulfilment of defined response criteria and p < 0.05 for comparison of the mean values for pain and function) in comparison to group 2. Although the numbers were small sub-analysis suggested that the differences might be due to a better response to newly administered DMARD and TNF-alpha-inhibitor therapy in group 1. Active RA patients with less than 2 swollen and 2 tender joints represent a subgroup with lower response to treatment with DMARD or TNF-alpha-inhibitors. This has to be taken into account in the management of these patients. [ABSTRACT FROM AUTHOR]

PurposeTo quantify the biometric changes of ocular dimensions with mechanical elevation of intraocular pressure (IOP) in vivo, to get a better understanding of the elastic properties of the human ocular structures that may play a role in the pathogenesis of various diseases such as myopia or glaucoma.MethodsChanges in IOP were induced by a suction cup in 18 eyes under cycloplegia. Axial eye length (AEL) and anterior chamber depth (ACD) were measured with non-invasive laser interferometry during elevation of the IOP 10 and 20 mmHg over baseline values and after a 10-min resting period.ResultsIOP elevation of 10 and 20 mmHg respectively caused a significant increase of AEL of 23 μm (95% confidence interval: 14–34 μm) and 39 μm (confidence interval (CI): 28–51 μm). After mechanical oculopression, which resulted in an IOP reduction of –5.1 mmHg (CI: −6.3 to −4.0 mmHg) vsbaseline, a significant shortening of −7 μm (CI: −13 to 0 μm) was observed. The change in AEL correlated with the change in IOP (r=0.66, P=0.005). Furthermore, a significant increase in ACD of 30 μm (CI: 24–36 μm) was detected with IOP reduction after oculopression, but no change was seen during IOP elevation.ConclusionsBiometric changes of the human eye as a response to IOP changes were assessed in vivo. The correlation between change in AEL and IOP found emphasizes the need of in vivoocular rigidity measurements in the human eye.Eye (2008) 22, 657–661; doi:10.1038/sj.eye.6702709; published online 19 January 2007 [ABSTRACT FROM AUTHOR]

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Discusses the generation of ultra-broad and smooth spectra from a mirror-dispersion-controlled Kerr-lens mode-locked titanium:sapphire lasers. Full width at half maximum of the spectrum; Evaluation of the pulse width; Use of interferometric autocorrelation.

In dieser Studie wird eine weitere Anwendung einer neuen, berührungsfreien Methode zur Dikkenmessung der Hornhaut in vitro vorgestellt. Die Laser-Doppler-Interferometrie (LDI), ursprünglich für die Messung intraokularer Abstände in vivo entwickelt, wurde erstmals für die Dickenmessung in vivo von menschlichen Spenderhornhäuten eingesetzt. Ein Teil der Spenderhornhäute wurde von vorne, d. h. mit der Epithelseite in Richtung Meßlaserstrahl, andererseits von hinten, mit der Endothelseite zum Meßlaserstrahl gewandt, gemessen, um die Einsetzbarkeit dieser neuen Meß-methodik zu testen. Der Vergleich zu herkömmlichen Meß-methoden wie der Ultraschall-Pachymetrie wird durch Kontrollmessungen vor und nach jeder LDI-Messung und dem Vergleich der erhaltenen Ergebnisse hergestellt. Es zeigt sich, daß die durch Ultraschall-Pachymetrie und Laser-Doppler-Interferometrie erhaltenen Gewebedicken sehr gut korellieren. Der wesentliche Vorteil dieser neuen Methode gegenüber konventionellen Meßmethoden zur Bestimmung der Gewebedicke einer Cornea besteht im berührungsfreien Meßaufbau, womit erstmals eine sterile Meßmethodik vorhanden ist. Weiters sind die hohe Präzision und die wesentlich kürzere Dauer des Meßvorganges von Vorteil. This study presents a new corneal pachymetry, using a Laser-Doppler-Interferometry (LDI) which was originally developed for biometry in vivo. For the first time this new system is used to determine the thickness of donor corneas in vitro. One part of the donor corneas was measured with the epithelial side, the other part with the endothelial side facing the laserbeam. The results of the measurements were compared with those of a conventional ultrasound method, thereby before and after each laser-Doppler-interferometry an ultrasound-pachymetry was carried out. Good agreement between both methods is observed. The advantages of this new method are on the one hand the set-up which allows non-contact measurements and guarantees for sterility, on the other hand the high precision and the short dwell-time compared to conventional methods. [ABSTRACT FROM AUTHOR]

Eine neue Methode zur Bestimmung intraokularer Distanzen in vivo wurde entwickelt. Sie beruht auf einer interferometrischen Technik mit teilkohärentem Licht in Verbindung mit dem Doppler-Prinzip. Die Methode wird am Beispiel der Messung der Achsenlänge des Auges demonstriert. Vergleichsmessungen mit der Ultraschalltechnik zeigen eine gute Übereinstimmung. Die Vorteile der neuen Technik liegen in der Berührungsfreiheit und der höheren Genauigkeit. A new method for determining intraocular distances has been developed. It is based on interferometry methods using partially coherent light in conjunction with the Doppler principle. The method is demonstrated in the case of axial eye length measurement. Comparisons with the ultrasound technique yield a good agreement. Avoiding mechanical contact between eye and instrument and achieving a higher precision are the main advantages of the new technique. [ABSTRACT FROM AUTHOR]

We present the technological verification of a size-optimized 160-channel, 50-GHz silicon nitride-based AWG-spectrometer. The spectrometer was designed for TM-polarized light with a central wavelength of 850 nm applying our proprietary "AWG-Parameters" tool. For the simulations of AWG layout, the WDM PHASAR photonics tool from Optiwave was used. The simulated results show satisfying optical properties of the designed AWG-spectrometer. However, the high-channel count causes a large AWG size with standard design approaches. To solve this problem we designed a special taper enabling the reduction of AWG structure by about 15% while keeping the same optical properties. The AWG design was fabricated and the measured spectra not only confirm the proposed size-reduction but also the improvement of optical properties of the size-optimized AWG. [ABSTRACT FROM AUTHOR]

In this work, we present a significant step toward in vivo ophthalmic optical coherence tomography and angiography on a photonic integrated chip. The diffraction gratings used in spectral-domain optical coherence tomography can be replaced by photonic integrated circuits comprising an arrayed waveguide grating. Two arrayed waveguide grating designs with 256 channels were tested, which enabled the first chip-based optical coherence tomography and angiography in vivo three-dimensional human retinal measurements. Design 1 supports a bandwidth of 22 nm, with which a sensitivity of up to 91 dB (830 µW) and an axial resolution of 10.7 µm was measured. Design 2 supports a bandwidth of 48 nm, with which a sensitivity of 90 dB (480 µW) and an axial resolution of 6.5 µm was measured. The silicon nitride-based integrated optical waveguides were fabricated with a fully CMOS-compatible process, which allows their monolithic co-integration on top of an optoelectronic silicon chip. As a benchmark for chip-based optical coherence tomography, tomograms generated by a commercially available clinical spectral-domain optical coherence tomography system were compared to those acquired with on-chip gratings. The similarities in the tomograms demonstrate the significant clinical potential for further integration of optical coherence tomography on a chip system.