A medical instrument is provided and includes a housing and a shaft coupled to the housing. The shaft has a proximal end and a distal end. An end-effector assembly is disposed at the distal end of the shaft. The end-effector assembly includes first and second jaw members. At least one of the first and second jaw members is movable from a first position wherein the first and second jaw members are disposed in spaced relation relative to one another to at least a second position closer to one another wherein the first and second jaw members cooperate to grasp tissue therebetween. The medical instrument also includes one or more light- emitting elements and one or more light-detecting elements configured to generate one or more signals indicative of tissue florescence. The one or more light-emitting elements are adapted to deliver light energy to tissue grasped between the first and second jaw members.

Surgical device with an end-effector assembly and system for monitoring of tissue during a surgical procedure

By doping an organic compound functioning as an electron donor (hereinafter referred to as donor molecules) into an organic compound layer contacting a cathode, donor levels can be formed between respective LUMO (lowest unoccupied molecular orbital) levels between the cathode and the organic compound layer, and therefore electrons can be injected from the cathode, and transmission of the injected electrons can be performed with good efficiency. Further, there are no problems such as excessive energy loss, deterioration of the organic compound layer itself, and the like accompanying electron movement, and therefore an increase in the electron injecting characteristics and a decrease in the driver voltage can both be achieved without depending on the work function of the cathode material.

Light Emitting Device

A series of YAG:Ce,Mn transparent ceramics were prepared via a solid-state reaction-vacuum sintering method. The effects of various Mn2+–Si4+ pair doping levels on the structure, transmittance, and luminescence properties were systematically investigated. These transparent ceramics have average grain sizes of 10–16 μm, clean grain boundaries, and excellent transmittance up to 83.4% at 800 nm. Under the excitation of 460 nm, three obvious emission peaks appear at 533, 590, and 745 nm, which can be assigned to the transition 5d→4f of Ce 3+ and 4T1→6A1 of Mn2+. Thus, the Mn2+–Si4+ pairs can effectively modulate the emission spectrum by compensating broad orange-red and red spectrum component to yield high quality warm white light. After the optimized YAG:Ce,Mn transparent ceramic packaged with blue light-emitting diode (LED) chips, correlated color temperature (CCT) as low as 3723 K and luminous efficiency (LE) as high as 96.54 lm/W were achieved, implying a very promising candidate for application in white light-emitting diodes (WLEDs) industry.

https://link.springer.com/content/pdf/10.1007/s40145-019-0346-0.pdf

Red-emitting YAG: Ce, Mn transparent ceramics for warm WLEDs application

3D rotation is one of many fundamental manipulations to cells and imperative in a wide range of applications in single cell analysis involving biology, chemistry, physics and medicine. In this article, we report a dielectrophoresis-based, on-chip manipulation method that can load and rotate a single cell for 3D cell imaging and multiple biophysical property measurements. To achieve this, we trapped a single cell in constriction and subsequently released it to a rotation chamber formed by four sidewall electrodes and one transparent bottom electrode. In the rotation chamber, rotating electric fields were generated by applying appropriate AC signals to the electrodes for driving the single cell to rotate in 3D under control. The rotation spectrum for in-plane rotation was used to extract the cellular dielectric properties based on a spherical single-shell model, and the stacked images of out-of-plane cell rotation were used to reconstruct the 3D cell morphology to determine its geometric parameters. We have tested the capabilities of our method by rotating four representative mammalian cells including HeLa, C3H10, B lymphocyte, and HepaRG. Using our device, we quantified the area-specific membrane capacitance and cytoplasm conductivity for the four cells, and revealed the subtle difference of geometric parameters (i.e., surface area, volume, and roughness) by 3D cell imaging of cancer cells and normal leukocytes. Combining microfluidics, dielectrophoresis, and microscopic imaging techniques, our electrorotation-on-chip (EOC) technique is a versatile method for manipulating single cells under investigation and measuring their multiple biophysical properties.

3D cell electrorotation and imaging for measuring multiple cellular biophysical properties

We present a novel method and instrument for in vivo imaging and measurement of the human corneal dynamics during an air puff. The instrument is based on high-speed swept source optical coherence tomography (ssOCT) combined with a custom adapted air puff chamber from a non-contact tonometer, which uses an air stream to deform the cornea in a non-invasive manner. During the short period of time that the deformation takes place, the ssOCT acquires multiple A-scans in time (M-scan) at the center of the air puff, allowing observation of the dynamics of the anterior and posterior corneal surfaces as well as the anterior lens surface. The dynamics of the measurement are driven by the biomechanical properties of the human eye as well as its intraocular pressure. Thus, the analysis of the M-scan may provide useful information about the biomechanical behavior of the anterior segment during the applanation caused by the air puff. An initial set of controlled clinical experiments are shown to comprehend the performance of the instrument and its potential applicability to further understand the eye biomechanics and intraocular pressure measurements. Limitations and possibilities of the new apparatus are discussed.

Assessment of corneal dynamics with high-speed swept source optical coherence tomography combined with an air puff system

A novel high speed interferometric ellipsometer (HSIE) is proposed and demonstrated. It is based on a novel differential-phase decoder which is able to convert the phase modulation into amplitude modulation in a polarized heterodyne interferometer. Not only high detection sensitivity but also fast response ability on ellipsometric parameters (EP) measurements based on amplitude-sensitive method is constructed whereas different amplitudes with respect to P and S polarized heterodyne signals in this phase to amplitude modulation conversion is discussed. The ability of HSIE was verified by testing a quarter wave plate while a real time differential-phase detection of a liquid crystal device versus applied voltage by using HSIE was demonstrated too. These results confirm that HSIE is able to characterize the optical property of specimen in terms of EP at high speed and high detection sensitivity experimentally.

High speed interferometric ellipsometer

With a Gaussian-like broadband light source from high brightness Ce3+:YAG single-clad crystal fiber, a full-field optical coherence tomography using a home-designed Mirau objective realized high quality images of in vivo and excised skin tissues. With a 40 × silicone-oil-immersion Mirau objective, the achieved spatial resolutions in axial and lateral directions were 0.9 and 0.51 μm, respectively. Such a high spatial resolution enables the separation of lamellar structure of the full epidermis in both the cross-sectional and en face planes. The number of layers of stratum corneum and its thickness were quantitatively measured. This label free and non-invasive optical probe could be useful for evaluating the water barrier of skin tissue in clinics. As a preliminary in vivo experiment, the blood vessel in dermis was also observed, and the flowing of the red blood cells and location of the melanocyte were traced.

Full-depth epidermis tomography using a Mirau-based full-field optical coherence tomography

A Ce(3+):YAG double-clad crystal fiber (DCF) visible emission was used as the light source for optical coherence tomography (OCT). The visible emission was produced from a 10 microm core DCF pumped by a diode laser. The broadband emission and short central wavelength of this light source enabled the realization of 1.5 microm axial resolution in air. The relatively clean spectrum reduced the side lobe of its point-spread function, and therefore facilitated the generation of a high-quality image with less crosstalk between adjacent image pixels. As a demonstration, an Aplocheilus lineatus goldfish was experimented on to map out the stroma of its cornea. This visible-light-based OCT can be utilized for industrial inspection as well as ocular applications.

Ce3+:YAG double-clad crystal-fiber-based optical coherence tomography on fish cornea.

A 3D OCT confocal imaging apparatus includes a light source module for providing an illumination beam with wider bandwidth from a crystal fiber; a reference source module; a pickup module; a beam splitter; an optical filter; and a sensor module. When the illumination beam illuminates a sample, a pickup objective lens and a piezoelectric actuator of the pickup module together provide an image beam scanning the sample in depth direction. The image beam and a reference beam from the reference source module together form an interference image beam, which is converted by a photosensor into a coherence image electric signal. Meanwhile, the interference image beam passes through a pinhole to form a confocal image, which is converted by an excited light photometer into a confocal image electric signal. With an image processing system, a 3D OCT confocal microscopic image of the sample can be produced from these image electric signals.

Three-dimensional optical coherence tomography confocal imaging apparatus

Shaping the ferroelectric domains as waveguide, grating, lens, and prism are key to the successful penetration of periodically-poled ferroelectrics on various wavelength conversion applications. The complicated structures are, however, difficult to be fully characterized, especially the unexpected index contrast at the anti-parallel domain boundaries are typical in the order of 10(-4) or less. An ultrahigh resolution optical coherence tomography was employed to fully characterize the domain boundary and structure properties of a periodically-poled lithium niobate (PPLN) waveguide with an axial resolution of 0.68 μm, an transversal resolution of 3.2 μm, and an index contrast sensitivity of 4x10(-7). The anti-parallel domain uniformity can clearly be seen non-invasively. Dispersion of the ferroelectric material was also obtained from 500 to 750 nm.

Chien-Chung Tsai

Papers

High speed interferometric ellipsometer

Full-depth epidermis tomography using a Mirau-based full-field optical coherence tomography

Ce3+:YAG double-clad crystal-fiber-based optical coherence tomography on fish cornea.

Three-dimensional optical coherence tomography confocal imaging apparatus

Non-invasive characterization of the domain boundary and structure properties of periodically poled ferroelectrics