The sophisticated high-level bioimaging instrument is a necessary implement for the pursuit of excellence in biomedical research. Which provides researchers to carry out qualitative and quantitative investigation of cells and molecularly-targeted in real, non-destructive, and complete in vivo. Furthermore, the image shows the physiological and pathological phenomena of cells or molecules directly, and convert the complex processes such as gene expression and biosignal transmission into images. Also, with the help of specific molecular probes, it is possible to achieve the goal of early diagnosis by discover disease symptoms under the molecular level. Therefore, it is necessary to possess a variety of biomedical optical imaging instruments with a variety of specific and special features for pursuing excellent biomedical research. Including:
Biomedical Tissue Optics
Skin Optics
Biomedical Spectroscopy
Biomedical Optics Systems
Medical Laser Technology

Raman spectroscopy

Raman spectroscopy is an increasingly popular technique in many areas, including biology and medicine. It is based on Raman scattering, a phenomenon in which incident photons lose or gain energy via interactions with vibrating molecules in a sample. These energy shifts can be used to obtain information regarding molecular composition of the sample with very high accuracy. Applications of Raman spectroscopy in the life sciences have included quantification of biomolecules, hyperspectral molecular imaging of cells and tissue, medical diagnosis, and others. In life science, Raman spectroscopy can identify and distinguish the sample, by the precision of a single cell level. In the near future, the combination of Raman spectroscopy and microscope technology will bring great benefits to life science research.

The most applications of Raman spectroscopy in life sciences includes:
Cellular
Proteomics
Immunology
Genomics
Cosmetology
Pharmacology
Biosecurity
Biomaterial
Environmental

Surface Enhanced Raman Scattering (SERS)

SERS can be considered as a good alternative to resonance Raman for several reasons. First, SERS is usually carried out with excitation in the visible-NIR range, minimizing sample damage. Second, SERS cross sections are much higher than those for RRS, permitting conformational characterization at very low concentrations and thus removing possible solid-state artefacts. Further, SERS permits the study of the native conformation and its natural fate under biological conditions, giving rise to direct information that is easy to extrapolate to real problems.

Tip-Enhanced Raman Spectroscopy (TERS)

A similar enhancement effect can be produced at the apex of a sharp gold-coated atomic force microscope tip. This tip-enhanced Raman scattering (TERS) microscopy has a resolution of around 10 nm, and imaging on this scale has been performed on carbon nanotubes which are very strong Raman scatterers.

Optical Tweezers (OT)

First demonstrated over 20 years ago, optical tweezers have become an established tool in research fields ranging from biophysics to cell biology. As their name suggests, optical tweezers use beams of light to hold and manipulate microscopically small objects such as biological molecules or even living cells. They are formed when a laser beam is tightly focussed to a tiny region in space using a microscope objective as a lens. This region becomes an optical trap that can hold small objects in 3D.

Optical tweezers can also make accurate measurements of the tiny, sub-picoNewton forces exerted on the trapped objects. This allows researchers to study the diffusion dynamics (or Brownian motion) of an object in a solvent – a property that can play a key role in the function of many biological molecules. Optical tweezers can also be used to micro manipulate an object using well-controlled forces.

Since their invention, optical tweezers have been used with great success in the field of single-molecule biophysics. For example, they have helped researchers unravel the complex elasticity and folding dynamics of DNA, RNA, proteins and other long-chain “biopolymers”. In these experiments, the biopolymers are typically manipulated from both ends either by suspending them between an optical trap and a surface or between multiple traps. Data obtained using optical tweezers complement measurements made using other techniques for measuring the forces on single molecules – including Atomic-Force Microscopy (AFM).

Microfluidic Platforms

Microfluidic platforms are well-known devices that enable the precise handling of liquids and the flow manipulation of multiple compounds in reaction chambers. The advantages of microfluidics are significant sample volume reduction, portability, automation and hazard control. Raman microscopy can be used in microfluidic devices, as it is possible to acquire spectra from very small volumes (<1 pL). Raman microscopy is a spectroscopic light scattering technique which provides image contrast based on the differences in the amplitude energies of the light scattering of vibrational states, which are characteristic for specific molecular bonds. Raman spectra represent a “fingerprint” of a chemical compound by which the compound can be identified without labelling. The method is nondestructive and compatible with measurements in aqueous environments because the Raman light scattering of water is relatively weak. Moreover, it offers high spatial resolution, common to optical microscopy, and high optical sensitivity due to high signal collection efficiency. The confocal Raman microscope system enables the targeting of specific areas in a sample; therefore, high discrimination between the sample of interest and other materials in the immediate surroundings of the sample can be achieved.

HyperSpectral Imaging (HSI)

Different from those traditional optical diagnostic methods, biomedical spectral imaging technology can capture the contiguous spectrum for each image pixel over a selected wavelength interval. This character makes it possible not only to detect some physiological changes of biological tissues by their reflectance or transmittance spectral signatures but also for early diagnosis of some diseases since the shapes of the spectra yield information about biological samples. The biomedical spectral images (i.e.: multispectral, hyperspectral) contain more information than the traditional monochrome, RGB, and spectroscopy methods. Biomedical spectral images make it possible to take advantage of the spatial relationships among the different spectra in a neighbourhood, which allows more elaborate spectral-spatial models for more accurate segmentation and classification of the image. Therefore, spectral imaging technology can find potential applications in pathology, cytogenetics, histology, immunohistology, and clinical diagnosis.

As an emerging imaging modality for medical applications, HSI offers great potential for noninvasive disease diagnosis and surgical guidance. Light delivered to biological tissue undergoes multiple scattering from inhomogeneity of biological structures and absorption primarily in hemoglobin, melanin, and water as it propagates through the tissue. It is assumed that the absorption, fluorescence, and scattering characteristics of tissue change during the progression of disease. Therefore, the reflected, fluorescent, and transmitted light from tissue captured by HSI carries quantitative diagnostic information about tissue pathology.

Applications
HSI is able to deliver nearly real-time images of biomarker information, such as oxyhemoglobin and deoxyhemoglobin, and provide assessment of tissue pathophysiology based on the spectral characteristics of different tissue. Therefore, HSI is increasingly being used for medical diagnosis and image-guided surgery.

Disease Diagnosis
HSI has tremendous potential in disease screening, detection, and diagnosis because it is able to detect biochemical changes due to disease development, such as cancer cell metabolism. In the literature, a variety of studies have used HSI techniques to augment existing diagnostic methods or to provide more efficient alternatives. In this section, diseases, such as different types of cancer, cardiac disease, ischemic tissue, skin burn, retinal disease, diabetes, kidney disease, and so on, are investigated by various HSI systems.

Image Guided Surgery
The success of surgery highly depends on a surgeon’s ability to see, feel, and make judgments to identify the lesion and its margins. MHSI holds the potential to extend a surgeon’s vision at the molecular, cellular, and tissue levels. The ability of MHSI as an intraoperative visual aid tool has been explored in many surgeries.

First, MHSI could help surgeons to visualize the surgical bed under the blood. Visual inspection is critical in microsurgery. However, the inevitable presence of blood spilling over the surgical field is a large visual obstacle to a successful surgery. Therefore, NIR HSI spectrograph was utilized to visualize tissues submerged in a blood layer that could not be seen with the naked eye.

Second, MHSI could facilitate residual tumor detection. Surgery remains the foundation of cancer treatment, with the central objective of maximizing the removal of the tumor, without harming adjacent normal tissue. However, cancerous tissue is often indistinguishable from healthy tissue in the operating room, which leads to the high mortality rates from recurrent tumors. The rationale of residual tumor detection by MHSI lies in the fact that MHSI is able to distinguish the spectral difference of the normal and cancerous tissue in nearly real time during the procedure.

Third, MHSI could monitor the tissue oxygen saturation during surgery. Tissue blood flow or oxygenation is a positive indicator of viable tissue, which might be otherwise sacrificed when removing tumor with little guidance. It has been shown that HSI could monitor the tissue at a rate of 3 frames per second and, thus, could detect dynamic changes in blood flow and capture unexpected events during surgery.

Finally, MHSI could enable the visualization of the anatomy of vasculatures and organs during surgery. MHSI has the capacity of real-time imaging, which enables the surgeon to make or confirm diagnosis and evaluate surgical therapy in an ongoing fashion in the operation room.

Overall, MHSI has been explored in surgeries, such as mastectomy, gall bladder surgery, cholecystectomy, nephrectomy, renal surgery, abdominal surgery, and intestinal surgery.