Patent Application
20140312247
The techniques described herein relate generally to biological imaging systems. More specifically, the techniques described herein relate to fluorescence imaging techniques using a mobile device.
According to certain embodiments, a method is provided for substantially simultaneously exciting a fluorescently labeled specimen and capturing fluorescent light emitted therefrom using a smartphone, tablet computer, mobile computer, or other similar device. The specimen can be excited using a light-emitting diode (“LED”) light source coupled with the smartphone and the fluorescent light emitted from the specimen can be captured using an imaging device coupled with the smartphone. Embodiments also include a hood device adapted to be coupled with the smartphone that has an excitation filter and an emission filter. The excitation filter can be adapted to produce a first wavelength of electromagnetic radiation to strike the specimen when light from the LED light source passes through it and the emission filter can be adapted to receive the fluorescent light emitted from the specimen and produce a second wavelength of electromagnetic radiation to be captured by the imaging device. In one embodiment, the second wavelength of electromagnetic radiation can be in the visible light spectrum for observation by users. In another embodiment, the second wavelength of electromagnetic radiation can be in the infrared (“IR”) spectrum. The specimen can then be detected based on the light captured by the imaging device.
Both the LED light source and the imaging device can be powered and controlled by the smartphone. In at least certain embodiments, the fluorescence of the specimen can be excited by a white light LED light source from the smartphone's flash or by a LED light source separate from the smartphone that is powered and controlled by the smartphone via a wired or wireless connection. Likewise, the emitted fluorescent light can be captured directly via the camera built into the smartphone or by an imaging device powered and controlled by the smartphone via a wired or wireless connection. The hood device can be configured to attach to the smartphone and includes at least two open apertures including (1) a first aperture for positioning the excitation filter over the front of the LED light source of the smartphone and (2) a second aperture for positioning the emission filter over the front of the lens of the imaging device of the smartphone. The hood device can also be designed to allow users to interchange the excitation and emission filters for use with different fluorophores. In some embodiments that hood may have multiple filters for either excitation, emission, or both, thereby allowing selection of the filters by users during operation.
In yet other embodiments, a system is provided for substantially simultaneously exciting a fluorescently labeled specimen and capturing fluorescent light emitted therefrom using a smartphone. The system in such an embodiment includes a LED light source coupled with the smartphone to excite the specimen and an imaging device coupled with the smartphone to capture fluorescent light emitted from the specimen. This embodiment also can include a hood adapted to be coupled with the smartphone. The hood includes (1) an excitation filter configured to produce a first wavelength of electromagnetic radiation to impact the specimen when light from the LED light source passes through it and (2) an emission filter configured to receive the light emitted from the specimen and to produce a second wavelength of electromagnetic radiation to be captured by the imaging device. The second wavelength of electromagnetic radiation can be in the visible light spectrum so that the specimen can be detected based on the light captured by the imaging device. In another embodiment, the second wavelength of electromagnetic radiation can be in the infrared spectrum.
These and other embodiments along with many of their advantages and features are described in more detail in conjunction with the following description, claims, and figures.
A better understanding of at least certain embodiments of the invention can be obtained from the following detailed description in conjunction with the following drawings, in which:
Throughout this description for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. In other instances, well-known structures and devices are shown in block diagram form to avoid obscuring the underlying principles of the described embodiments.
The systems and methods introduced herein are adapted to substantially simultaneously excite a fluorescently labeled specimen and capture fluorescent light emitted therefrom using a device such as a smartphone, tablet computer, mobile computer, or other similar device. Reference is made herein to using a smartphone. It is understood that the smartphone is referenced as an exemplary device and that embodiments of the invention are not limited to using a smartphone.
“Fluorescence” is the emission of visible or invisible radiation produced from certain substances as a result of absorbing incident electromagnetic radiation of a (generally) shorter wavelength such as x-rays or ultraviolet light. It is the property of absorbing light of shorter wavelength and emitting light of a longer one. In most cases, the emitted light has a longer wavelength, and therefore lower energy, than the absorbed radiation. The most striking examples of fluorescence occur when the absorbed radiation is in the ultraviolet region of the spectrum, and thus invisible to the human eye, and the emitted light is in the visible region of the spectrum and can be perceived by humans.
In one embodiment, the specimen is a fluorescently labeled protein (e.g., a labeled antibody). The specimen can be excited using a LED light source coupled with the smartphone and the fluorescent light emitted from the specimen can be captured using an imaging device coupled with the smartphone. Fluorescent labeling is the process of covalently attaching a “fluorophore” to another molecule, such as a protein or nucleic acid. A fluorophore (or fluorochrome) is a fluorescent chemical compound that can re-emit light upon excitation. Fluorophores typically contain several combined aromatic groups, or plane or cyclic molecules with several π bonds. Fluorophores are sometimes used alone, as a tracer in fluids, as a dye for staining of certain structures, as a substrate of enzymes, or as a probe or indicator (when its fluorescence is affected by environment such as polarity, ions, etc.). But more generally fluorophores are covalently bonded to a macromolecule, serving as a marker (e.g., dye, tag, or reporter) for bioactive reagents (e.g., antibodies, peptides, nucleic acids). Fluorophores are notably used to stain tissues, cells, or materials in a variety of analytical methods, such as fluorescent imaging and spectroscopy.
Fluorescent labeling is generally accomplished using a reactive derivative of the fluorophore that selectively binds to a functional group contained in the target molecule. The most commonly labeled molecules are antibodies, proteins, amino acids and peptides which are then used as specific probes for detection of a particular target. Fluorescent labels are generally used for detection of a protein or other labeled molecule via a fluorescence microscope, flow cytometer or some other fluorescence reading instrument. These can be useful in localization of a target within a cell, flow cytometry (FACS) analysis, western blot assays, and other immunoanalytical methods.
In some embodiments, the LED light source is coupled with the smartphone (as part of the smartphone or physically separate from the smartphone) and under the control of the smartphone. Other similar mobile computing devices can also be used such a tablet or mobile computer, etc. The light source can either be a LED contained within the smartphone (e.g., the white light LED that is used for flash on the smartphone), or it can be a LED (Red, Green, or Blue) that is directly powered by the smartphone battery and controlled via a data or power cable attached to the smartphone. Alternatively, the light source (still considered “coupled with”) can be separate from, and under the control of the smartphone. For instance, the light source can be an LED (Red, Green, or Blue) that is controlled by the smartphone via a Bluetooth connection and powered separately. The emitted fluorescent light from the specimen can then be captured directly via the smartphone camera system or by a camera system that is controlled and powered by the smartphone.
The camera system can be powered and controlled using a data/power cable attached to the smartphone or by a camera system that is controlled by the smartphone via a Bluetooth connection and powered separately. For instance, such a technique can be used to avoid a problem that occurs whereby many modern mobile devices include imaging devices that automatically filter out infrared light to improve picture quality. The embodiments described herein are not limited to any particular type of wired or wireless network connection. In addition, the coupling of the LED with the smartphone can be a direct connection or a functional connection. In one embodiment, there may be one or more intermediate components coupled between the smartphone and the LED.
The LED light source of the smartphone can be used for excitation of these fluorescently labeled proteins that have been captured on a membrane. In some embodiments, the membrane can typically be of polyvinylidene fluoride (“PVDF”) or nitrocellulose. The proteins (or nucleic acids) in the specimen can be transferred to the membrane where they can be stained with fluorescently-labeled antibodies specific to the target protein. Polyvinylidene fluoride (or polyvinylidene difluoride) is a highly non-reactive thermoplastic fluoropolymer produced by the polymerization of vinylidene difluoride. A fluoropolymer is a fluorocarbon based polymer with multiple strong carbon-fluorine bonds. It is characterized by a high resistance to solvents, acids, and bases. PVDF is a specialty plastic material in the fluoropolymer family; it is used generally in applications requiring the highest purity, strength, and resistance to solvents, acids, and bases. Other embodiments are adapted to be used in conjunction with microplates, microscope slides, microarrays, or other materials commonly used with fluorescent detection in biochemistry.
Embodiments can also include a “hood” adapted to be coupled with the smartphone that has an excitation filter and an emission filter. The excitation filter can be adapted to produce a first wavelength of electromagnetic radiation to strike the specimen when light from the LED light source passes through the excitation filter and the emission filter can be adapted to receive the fluorescent light emitted from the specimen and produce a second wavelength of electromagnetic radiation to be captured by the imaging device. In one embodiment, the second wavelength of electromagnetic radiation is in the visible light spectrum for observation by users. The specimen can then be detected based on the light captured by the imaging device. In another embodiment, the second wavelength of electromagnetic radiation is in the infrared spectrum. Using emitted infrared light can be advantageous because there are no known naturally occurring fluorescent materials in biological specimens that emit light in the infrared spectrum when excited. It may be desirable in certain applications to image the emitted infrared light instead of visible light to reduce any spurious or false-positive signals that may be emitted from a particular specimen in the visible light spectrum.
In the case where fluorescence and detection are carried out via the white light LED and camera directly attached to the smartphone, the hood can be provided that is designed to be attached over the smartphone. In one embodiment, the hood is designed to have two open apertures which allow for the insertion of the excitation and emission filters respectively to control the wavelength of light striking the fluorophore and the wavelength of the emitted light that reaches the image sensor of the camera. The hood can be designed such that it snaps into place over the smartphone in such a way that the aperture for the excitation filter is positioned over the front of the LED light source of the smartphone and the aperture for the emission filter is positioned over the front of the lens of the smartphone camera. Other ways of coupling the hood device with the smartphone can also be used and the embodiments described herein are not intended to be limited by any particular mechanism for attaching the hood device to the smartphone.
In addition, the hood can also be designed to easily interchange the excitation and emission filters for various fluorophores. In some embodiments the hood may have multiple filters for either excitation, emission, or both, thereby allowing selection of the filters to be used during operation. For example, multiple filters may be built-into a rotating wheel (or wheels) that allows different filters to be selected by users and are disposed such that each filter can be rotated into place for performing the operations described herein. In addition, if the camera within the smartphone or tablet computer does not have a built-in filter to remove infrared light it may be possible to detect this IR radiation with the appropriate emission filter. Many devices include a built-in filter for IR radiation to improve picture quality.
An example block diagram of the hood coupled with a smartphone is shown in
In one embodiment, the “Western Blot” technique can be used for detecting the specimen. Western Blot (sometimes called the protein immunoblot) is a widely accepted analytical technique used to detect specific proteins in the given sample of tissue. It uses gel electrophoresis to separate native proteins by 3-D structure or denatured proteins by the length of the polypeptide. In one embodiment, the method and system are adapted to analyze one or more proteins (or nucleic acid) present in a western blot (western blotting is generally described in, e.g, Sambrook et al. (Molecular Cloning: A Laboratory Manual; Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y., (1989); Current Protocols in Molecular Biology, Ausubel et al., Green Pub. Associates and Wiley-Interscience, New York (1988); Yeast Genetics: A Laboratory Course Manual, Rose et al., Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y., (1990)). The analysis of the specimen after the image has been captured can also be performed using an application running on the smartphone. The techniques disclosed herein are not limited to western blots as these techniques can be used in conjunction with a Southern blot and northern blot, etc.
In at least certain embodiments, the specimen is a macro specimen that does not require a microscope to be incorporated into the system to obtain useable images of the specimen. In other embodiments, the specimen may be a micro-specimen and a microscope can be incorporated into the system. In all iterations of the device, software applications within the smartphone 301 can be provided to control the light sources 310 and the imaging sensor of the smartphone's camera during excitation and emission of the fluorescently labeled proteins. In addition, software can be written to further process, analyze, and transmit the collected data. The light emitted from the specimen 317 is collected by the camera thereby capturing an image of the fluorescent light.
The light emitted from the specimen is filtered using an emission filter adapted to receive the fluorescent light emitted from the specimen and produce a second wavelength of electromagnetic radiation to be captured by the imaging device (operation 504). In one embodiment, the second wavelength of electromagnetic radiation is in the visible light spectrum for observation by users. In another embodiment, the second wavelength of electromagnetic radiation is in the infrared spectrum. The specimen can then be detected based on the light captured by the imaging device (operation 505). This completes process 500 according to one example embodiment.
In addition, distortion characteristics of camera systems can be corrected via calibration or image processing. Such techniques have generally been disclosed in the following U.S. Patent Applications: (1) U.S. patent application Ser. No. 10/174,510 entitled “Flat Field Correction of Digital Images of Electrophoresis Gels by Use of Reference Illumination,” filed Jun. 17, 2002; (2) U.S. patent application Ser. No. 08/814,126 entitled “A Method and Apparatus for Correcting Illumination Non-Uniformities,” filed Mar. 10, 1997; and (3) U.S. patent application Ser. No. 12/791,795 entitled “Calibration of Imaging Device for Biological/Chemical Sample,” filed Jun. 1, 2010, each of which is incorporated into this application by reference in its entirety.
Provided below are descriptions of some devices (and components of those devices) that may be used in the systems and methods described above. These devices may be used, for instance, to receive, transmit, process, or store data related to any of the functionality described above. As will be appreciated by one of ordinary skill in the art, the devices described below may have only some of the components described below, or may have additional components.
As shown, the data processing system 600 includes a system bus 602 which is coupled to a microprocessor 603, a Read-Only Memory (ROM) 607, a volatile Random Access Memory (RAM) 605, as well as other nonvolatile memory 606. In the illustrated embodiment, microprocessor 603 is coupled to cache memory 604. System bus 602 can be adapted to interconnect these various components together and also interconnect components 603, 607, 605, and 606 to a display controller and display device 608, and to peripheral devices such as input/output (“I/O”) devices 610. Types of I/O devices can include keyboards, modems, network interfaces, printers, scanners, video cameras, or other devices well known in the art. Typically, I/O devices 610 are coupled to the system bus 602 through I/O controllers 609. In one embodiment the I/O controller 609 includes a Universal Serial Bus (“USB”) adapter for controlling USB peripherals or other type of bus adapter.
RAM 605 can be implemented as dynamic RAM (“DRAM”) which requires power continually in order to refresh or maintain the data in the memory. The other nonvolatile memory 606 can be a magnetic hard drive, magnetic optical drive, optical drive, DVD RAM, or other type of memory system that maintains data after power is removed from the system. While
It will be apparent from this description that aspects of the described techniques may be embodied, at least in part, in software, hardware, firmware, or any combination thereof. It should also be understood that embodiments can employ various computer-implemented functions involving data stored in a data processing system. That is, the techniques may be carried out in a computer or other data processing system in response executing sequences of instructions stored in memory. In various embodiments, hardwired circuitry may be used independently, or in combination with software instructions, to implement these techniques. For instance, the described functionality may be performed by specific hardware components containing hardwired logic for performing operations, or by any combination of custom hardware components and programmed computer components. The techniques described herein are not limited to any specific combination of hardware circuitry and software.
Embodiments herein may also be in the form of computer code stored on a computer-readable medium. Computer-readable media can also be adapted to store computer instructions, which when executed by a computer or other data processing system, such as data processing system 600, are adapted to cause the system to perform operations according to the techniques described herein. Computer-readable media can include any mechanism that stores information in a form accessible by a data processing device such as a computer, network device, tablet, smartphone, or any device having similar functionality. Examples of computer-readable media include any type of tangible article of manufacture capable of storing information thereon such as a hard drive, floppy disk, DVD, CD-ROM, magnetic-optical disk, ROM, RAM, EPROM, EEPROM, flash memory and equivalents thereto, a magnetic or optical card, or any type of media suitable for storing electronic data. Computer-readable media can also be distributed over a network-coupled computer system, which can be stored or executed in a distributed fashion.
Throughout the foregoing description, for the purposes of explanation, numerous specific details were set forth in order to provide a thorough understanding of the invention. It will be apparent, however, to persons skilled in the art that these embodiments may be practiced without some of these specific details. Accordingly, the scope and spirit of the invention should be judged in terms of the claims which follow as well as the legal equivalents thereof.
This application claims the benefit of Provisional Application No. 61/813,457, filed Apr. 18, 2013, entitled “Fluorescence Imager On a Mobile Device,” the disclosure of which is hereby incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61813457 | Apr 2013 | US |
