Patent Description:
Each year, in the United States, about <NUM> million nasogastric tubes are placed in patients with a significant fraction of such tubes placed in pediatric patients. One example of a nasogastric tube is a nasogastric feeding tube that can be used to administer water, nourishment and/or medicine to a patient. For example, a so-called Dobbhoff feeding tube is a small-bore flexible tube that can be inserted through a patient's nose to the stomach, and from the stomach to the first part of the small intestine (duodenum). It can be made of a radiopaque polymeric material to allow its placement using an X-ray or fluoroscope. A nasogastric tube can also be employed for other purposes. For example, a nasogastric tube can be in the form of a large bore tube that can be used for a variety of different purposes, such as decompressing the stomach for surgery and to prevent nausea/vomiting.

Although placement of nasogastric tubes in patients is relatively routine, there is a risk associated with each insertion. A misplaced nasogastric tube can lead to serious and even fatal complications. One conventional method for verification of the placement of a nasogastric tube is the measurement of the acidity of the gastric aspirate. Another method is the use of radiography to verify the location of the nasogastric tube. These conventional methods, however, suffer from a number of shortcomings. For example, the measurement of acidity can result in false affirmation of the placement of the nasogastric tube. Further, the radiation exposure associated with radiography is of great concern in pediatric patients.

<CIT> discloses methods and systems for locating a feeding tube inside of a person, including a light source configured to generate light coupled to a light transmitting element. <CIT> discloses a method for catheter placement, which includes inserting light from a small laser diode into a distal end of a catheter and passing the light through an optical fiber. <CIT> discloses a three-dimensional optical guidance for catheter placement. This system comprises an optically-guided catheter. <CIT> discloses a light-guided transluminal catheter for direct visualization of placement through the skin. <CIT> discloses a living body monitoring device capable of receiving weak light emitted from a living body.

Accordingly, there is a need for improved nasogastric feeding devices as well as improved methods for their insertion into a patient's gastrointestinal tract.

The above object is solved by a system according to claim <NUM>.

According to the present invention there is provided a system for illuminating a lumen within a body of a patient, comprising:.

Further aspects are defined in the dependent claims.

The present invention is directed to the ability to illuminate via light an internal or interior lumen of a patient via a fiber optic cable and an attached light source such that at least a portion of the light can be externally observed, e.g., via the naked eye or a camera. The observed light can be employed to guide a diagnostic and/or therapeutic tube (e.g., a catheter) through the lumen. The interior lumen can be any suitable lumen such as a nasogastric passage, a cardiac passage and the like.

According to one practice, an example is directed to an illumination system for illuminating a lumen within a body of a patient, comprising a tube having a proximal end and an opposed distal end and an internal chamber, where the tube is configured for placement within a lumen of the body, and an illumination subsystem including an optical fiber that is sized and configured to seat within the internal chamber of the tube and a light source for generating light that is emitted by the fiber optic cable. The optical fiber, when mounted within the tube and when the light source generates light, emits light at the distal end of the tube so as to transilluminate the lumen and surrounding tissue so as to be able to locate (e.g., visually or with an external device such as a camera) the distal end of the tube within the lumen of the patient.

The tube has at least one opening formed in a wall thereof, and the optical fiber has a proximal end configured for receiving light from the light source and a distal end having at least one light-emitting segment formed therein through which light from the light source exiting the optical fiber. The optical fiber is coupled to the tube such that the at least one light-emitting segment is located substantially adjacent to the at least one opening in the wall of the tube, whereby at least a portion of the light exiting the optical fiber through the at least one opening can be detected externally for guiding placement of the tube in the lumen. The light emitting segment and the opening are disposed can be disposed in registration with each other.

According to another practice, the tube can include a plurality of openings formed in a wall thereof, where the optical fiber includes at least one light-emitting segment for emitting light received from the light source, and wherein the light-emitting segment is disposed in registration with one of the plurality of openings.

The tube can include a plurality of openings formed in a wall thereof, and the optical fiber can include a plurality of light-emitting segments for emitting light received from the light source, wherein each of the light-emitting segments is disposed in registration with one of the plurality of openings.

According to one embodiment, the illumination system can be configured such that the tube corresponds to a nasogastric device. The tube has a proximal end and a distal end and is configured for placement in an individual's gastrointestinal tract, where the tube has at least one opening in a wall thereof. The nasogastric device further includes at least one fiber optic (herein also referred to as an optical fiber) extending from a proximal end configured for receiving light from a light source to a distal end through which the light exits the fiber optic, the fiber optic having at least one light-emitting segment through which light exits the fiber optic, the fiber optic being coupled to said tube such that said at least one light-emitting segment of the fiber optic is located substantially adjacent to said at least one opening in the tube wall, whereby at least a portion of the light exiting the fiber optic through said at least one opening passes through said opening and propagates through tissue to be detected externally for guiding deployment and placement of the nasogastric feeding tube in the individual's gastrointestinal tract.

In some embodiments, the nasogastric device can be a nasogastric feeding tube, which includes a passageway for administration of nourishment and/or medicine to a patient. In other embodiments, a nasogastric device according to the present teachings can be used for other purposes. For example, the nasogastric device can include a passageway to which a negative pressure can be applied for decompressing the stomach for surgery and/or to prevent nausealvomiting.

In some embodiments, one or more light-emitting segments of the fiber optic can be positioned in a distal region of the fiber. In some such embodiments, one or more light-emitting segments of the fiber optic can be configured so as to provide side emission of the light. In some embodiments, one or more light-emitting segment(s) of the fiber optic can be configured to emit light from the distal end of the fiber optic. In some such embodiments, the light is emitted along an axial direction of the fiber optic with the divergence of the emitted light resulting in at least a portion of the light being observed externally in such a way as to allow guiding the tube along the patient's gastrointestinal tract. Further, in some embodiments in which the light is emitted from the distal end of the fiber optic, the distal region of the fiber optic is bent so as to be in substantial register with an opening in the tube, thereby enhancing the optical coupling between the light emitted by the fiber and that opening.

In some embodiments, the tube of a nasogastric device can include a plurality of openings and the fiber optic can include a plurality of light-emitting segments. In some such embodiments, the fiber optic is disposed within the tube such that each of the plurality of light-emitting segments is in substantial register with one of the openings in the tube so as to emit light in a plurality of directions in order to facilitate the placement of the tube within a patient's gastrointestinal tract. In some embodiments, the plurality of openings are disposed in the tube so as to allow monitoring the tube regardless of its rotational orientation as it is being guided along a patient's gastrointestinal tract. By way of example, the plurality of openings can be distributed substantially uniformly around a cross-sectional circumference of the tube.

In some embodiments, the fiber optic can be attached, e.g., glued, to an inner surface of the tube's wall. Such placement of the fiber optic can advantageously facilitate monitoring the tube via transillumination.

The tube can be formed of a variety of different polymeric materials. In general, any suitable polymeric material can be used. Some examples of such materials include, without limitation, silicone rubber, and polyurethane.

The nasogastric device can further include a light source that is optically coupled to the optical fiber to provide light thereto. For example, the light source can be coupled to the proximal end of the optical fiber to deliver light to the fiber. A variety of light sources can be employed in the practice of the invention. Some examples of suitable light sources include, without limitation, a light-emitting diode (LED), a laser diode, and an incandescent light source, among others. While in some embodiments, the light source can emit visible radiation, in other embodiments, the light source can emit radiation in the near-infrared region of the electromagnetic spectrum. Further, while in some embodiments, the emitted light can be white light, in other embodiments, the light source can emit substantially monochromatic light, e.g., red light. In some embodiments, the light source can emit light with wavelengths in a range of about <NUM> to about <NUM>.

In some embodiments, the optical fiber is a single-mode fiber while in other embodiments, it can be a multi-mode fiber. The optical fiber can have, for example, a diameter in a range of about <NUM> to about <NUM>, though other diameters can also be used so long as the fiber can be inserted within the nasogastric tube.

In some embodiments, an external detector can be utilized to detect externally the light emitted by the optical fiber so as to allow guiding the fiber through the patient's gastrointestinal tract. For example, in some such embodiments, a camera can be employed to the detect the light passing through the tissue. In some such embodiments, the camera can be a visible or an infrared camera.

In a related aspect, a nasogastric device is disclosed, which includes a tube having a proximal end and a distal end and is configured for placement in an individual's gastrointestinal tract. The tube can include a tubular side wall that is configured for receiving, at its proximal end, light from a light source. The tubular side wall is substantially transparent to the received light such that the light is partially transmitted along the tubular wall and is partially transmitted to external environment via passage through an outer surface of the tubular wall to be detected externally after passage through tissue for guiding deployment and placement of the nasogastric feeding tube in the individual's gastrointestinal tract.

In some embodiments, the nasogastric device can be a nasogastric feeding tube, which includes a passageway for administration of medicine and/or nourishment to a patient. In other embodiments, a nasogastric device according to the present teachings can be used for other purposes. For example, the nasogastric device can include a passageway to which a negative pressure can be applied for decompressing the stomach for surgery and/or to prevent nausealvomiting.

By way of example, the tubular wall can be formed of clear silicone rubber, or any other suitable material.

In some embodiments, a plurality of light sources are optically coupled to the proximal end of the tubular wall to deliver light from multiple points to the tubular wall so as to ensure that substantially the entire tubular wall is illuminated. This can allow for external monitoring of the tube regardless of its rotational orientation in the individual's gastrointestinal tract.

In a related aspect, a nasogastric feeding device is disclosed, which includes a tube having a proximal end and a distal end and configured for placement in an individual's gastrointestinal tract. A light-emitting diode (LED) is coupled to the tube such that at least a portion of the light emitted by the LED passes through the opening. At least a portion of the light passing through the opening can pass through at least a portion of the surrounding tissue to be detected externally for guiding the deployment and placement of the nasogastric tube in the individual's gastrointestinal tract. For example, the LED can be positioned in the distal region of the feeding tube in proximity (and preferably in substantial register) with the opening in the distal region of the tube to allow efficient coupling of the light emitted by the LED into the tube's opening. A plurality of conductors extending through the tube can be coupled to the LED to supply electrical power thereto. In some embodiments, the conductors can be placed within an electrically insulating sleeve.

In yet another aspect, a gastrointestinal feeding device is disclosed, which includes a feeding tube having a proximal end and a distal end. A lens is coupled to the distal end of the tube. Further, an optical fiber is positioned in the tube such that its distal end is optically coupled to the lens. A light source can be used to deliver light to a proximal end of the optical fiber. The light can be emitted by the optical fiber at its distal end to be coupled to the lens. In some embodiments, a divergent lens is employed, which can cause divergence of the light received from the optical fiber such that at least a portion of the light is transmitted through at least a portion of the surrounding tissue to be monitored externally (e.g., via visualization and/or via an external detector (such as a camera)). The lens can be formed of a variety of different materials, such as a variety of suitable polymeric materials.

In a related aspect, a nasogastric device is disclosed, which includes a tube having a proximal end and a distal end and configured for placement in an individual's gastrointestinal tract, said tube having a window in a wall thereof, and at least one fiber optic having a proximal end configured for receiving light from a light source and a distal end, where the fiber optic has at least one light-emitting segment. The fiber optic is coupled to the tube such that said at least one light-emitting segment of the fiber optic is located substantially adjacent to said at least one window in the tube wall, whereby at least a portion of the light exiting the fiber optic through said at least one opening can be detected externally for guiding deployment and placement of the nasogastric tube in the individual's gastrointestinal tract.

In some embodiments, the window is substantially transparent to the light emitted by the fiber optic. In some embodiments, the tube includes a plurality of windows through one or more of which the light emitted by the fiber optic transilluminate at least a portion of the tissue surrounding the tube. In some embodiments, the window can include a color filter. In some embodiments, the nasogastric device is configured for administering any of medicine and/or nourishment to a patient. In some embodiments, the nasogastric device is configured for applying suction to a patient's stomach.

Further understanding of various aspects of the invention can be obtained by reference to the following detailed description in conjunction with the associated drawings, which are described briefly below.

These and other features and advantages of the present invention will be more fully understood by reference to the following detailed description in conjunction with the attached drawings in which like reference numerals refer to like elements throughout the different views. The drawings illustrate principals of the disclosure and, although not to scale, show relative dimensions.

The present invention generally relates to systems, and devices for illuminating a lumen within a human body, and can include for example a tube for positioning in a lumen within a patient, where the tube includes at least an opening and/or a window in a distal region thereof. Such a device can include an illumination system or subsystem for delivering light to the tube such that at least a portion of the delivered light exits through the opening and/or window to be detected externally (via visualization or otherwise), thereby allowing a user to guide the placement of the tube within the lumen. As used herein, the term "lumen" is intended to include any internal passage or opening within the human body, and can include nasal passages, gastric passages and chambers, intestinal tracts and openings, esophageal passages, cardiac passages, venous, capillary and aortic passages, bronchial passages, uterine tracts and openings, and the like. According to one embodiment of the present invention, the invention allows positioning a gastrointestinal tube or a cardiac tube via transillumination. In some embodiments, the illumination subsystem can include an optical fiber that is positioned within the tube to transmit light received from a remote light source to the opening (and/or window) disposed in the distal region of the tube. In other embodiments, a light source can be positioned within the tube to deliver light to the opening (and/or window). Further, in some embodiments, a lens can be coupled to the distal end of the tube to receive light from an optical fiber positioned within the tube. In some such embodiments, the lens can be a divergent lens that causes the divergence of the light incident thereon such that at least a portion of the light would exit a portion of the surrounding tissue to be detected externally. A nasogastric device according to the present teachings can be used for a variety of different purposes. For example, in some embodiments, the nasogastric device can be configured for administering medicine and/or nourishment to a patient. In other embodiments, a nasogastric device according to the present teachings can be used for decompressing the stomach for surgery and/or to prevent nausealvomiting. While in some embodiments discussed below, a nasogastric device according to the present teachings is configured as a nasogastric feeding device for administering nourishment and/or medicine to a patient, it should be understood that the teachings of the present invention are equally applicable to other types of nasogastric devices, e.g., those that are configured for decompressing a patient's stomach.

Various terms are used herein according to the ordinary meanings, unless indicated otherwise. The terms "light" and "radiation" are used herein interchangeably to refer not only to visible radiation but also to radiation in other regions of the electromagnetic spectrum, such as near-infrared. Further, the terms "fiber optic" and "optical fiber" are used herein interchangeably to refer to a waveguide through which electromagnetic radiation can be transmitted. The term "visible light" as used herein refers to radiation wavelengths in a range of about <NUM> to about <NUM>, the term "near-infrared radiation" refers to radiation having wavelengths in a range of about <NUM> to about <NUM>. The term "transillumination" as used herein refers to the passage of light through a body portion, e.g., to allow guiding a tube through a body lumen.

<FIG> schematically depict an illumination system that can deliver light to a specific location or site within a lumen of the human body. According to one practice, the illumination system can be configured as a nasogastric system <NUM> that includes a tube <NUM> configured for placement in a lumen of a patient, such as for example in a gastrointestinal tract for administration of enteral nutrition or compression of the stomach. The tube <NUM> has a proximal end 12a and a distal end 12b. In some embodiments, the tube <NUM> terminates in an outlet port <NUM>. An inlet port <NUM> is fluidly coupled to the proximal end of the tube <NUM> via a tube section <NUM>. The inlet port <NUM> can be configured as any suitable port, such as a sump port. In some embodiments in which the nasogastric system <NUM> is configured for administering nourishment and/or medicine to a patient, the outlet port <NUM> can be used for introducing such nourishment and/or medicine to the patient's gastrointestinal tract. In other embodiments, the outlet port <NUM> can be used to connect the tube to a pump, e.g., to remove air from the patient's stomach, so as to enhance visibility of any light emitted from the tube <NUM>. The tube <NUM> can include a plurality of openings 30a, 30b, 30c, and 30d (herein collectively referred to as openings <NUM>) disposed in the distal end 12b of the tube <NUM>. As discussed in more detail below, at least one of the openings <NUM> can allow for the passage of light emitted from an optical fiber incorporated into an internal chamber 12d of the tube so as to allow tracking of the tube <NUM>, such as for example by visualization or by detection via a detector, as the tube is being inserted and guided within a lumen, such as the gastrointestinal tract of the patient.

More specifically, the nasogastric system <NUM> includes an optical fiber <NUM> that can be attached to an inner wall 12c of the tube <NUM> and can extend from the proximal end 12a of the tube <NUM> to the distal end 12b. In some embodiments, the optical fiber <NUM> can be attached to the inner wall 12c of the tube in a variety of different ways. By way of example, as shown schematically in <FIG>, the optical fiber <NUM> can be glued to an inner wall 12c of the tube <NUM>.

In other embodiments, the optical fiber <NUM> can be disposed in the tube <NUM> such that the optical fiber <NUM> can be inserted or extracted after the tube <NUM> is placed in the patient's gastrointestinal tract, e.g., after the distal region 12b of the tube <NUM> is placed within the patient's stomach and/or duodenum. For example, the optical fiber <NUM> can be inserted in the tube <NUM> without gluing or otherwise affixing the optical fiber to the tube. The illustrated optical fiber <NUM> has a proximal end 20a and a distal end 20b. The proximal end 20a of the optical fiber <NUM> is optically coupled to a light source <NUM>. The light source <NUM> can have any selected size, shape or configuration, and can employ any suitable type of radiation or light element for producing the light and can be coupled to any suitable type of power source. According to one embodiment, the light source <NUM> can be configured as a handheld battery-operated light source that is capable of generating light. A variety of light sources emitting light in the visible and/or infrared region of the electromagnetic spectrum can be employed. In this embodiment, the handheld light source <NUM> includes a light emitting diode (LED). In some embodiments, white light with wavelengths in a range of <NUM> to <NUM> with a minimum of about <NUM> CCT (Correlated Color Temperature) to about <NUM> CCT can be used. Alternatively, monochromatic light (e.g., red light) or non-visible light (e.g., with wavelengths greater than <NUM>), i.e., near-infrared (<NUM> - <NUM>) can be employed. In other embodiments, an LED emitting radiation in the infrared portion of the electromagnetic spectrum, e.g., in a wavelength range of about <NUM> to <NUM>, can be employed. An example of such an LED is marketed by CREE under the trade designation Photo Red LED (XQEEPR). Further, the optical fiber can be composed of any suitable material, such as plastic.

With reference to <FIG> and <FIG>, the light source <NUM> includes a light element, such as the LED <NUM> that is disposed in an enclosure <NUM> provided in a housing <NUM> of the light source. A lens <NUM> is also provided in the enclosure <NUM> and is optically coupled to the LED <NUM> to receive light therefrom. The housing also mounts a lens <NUM> that includes a collar 31a that can be seated on a shoulder <NUM> provided within the enclosure <NUM> to maintain the lens <NUM> in the enclosure and in optical coupling or communication with the LED <NUM>. A fiber optic adapter <NUM> can be removably and replaceably received in the upper hollow cylindrical portion <NUM> of the housing <NUM> to allow coupling the optical fiber <NUM> to the LED <NUM>. In this embodiment, the fiber optic adapter <NUM> can include a plurality of threads <NUM> that can engage with a plurality of mating threads <NUM> provided on the inner wall of the upper hollow cylindrical portion <NUM>.

The lens <NUM> includes a proximal portion <NUM> and a distal portion <NUM>. The proximal portion <NUM> of the lens includes a recess <NUM> through which light from the LED <NUM> can enter the lens. The proximal portion <NUM> includes a lateral surface 40a that is configured to reflect light incident thereon via total internal reflection toward the distal portion. Some of the light entering the lens via the recess <NUM> passes through the proximal portion of the lens without undergoing reflections at the lateral surface 40a thereof to reach the distal portion of the lens. The light passes through the distal portion of the lens and exits an output surface <NUM> of the lens. In this embodiment, an optical window <NUM> is disposed over the output surface <NUM> of the lens. The optical window <NUM> can protect the output surface of the lens and, in some embodiments, the optical window <NUM> can adjust one or more characteristics of the light exiting the lens. By way of example, the optical window <NUM> can be selected to function as a filter, e.g., a bandpass filter, to allow passage of certain wavelengths of light exiting the lens while blocking other wavelengths.

In some embodiments, the lens <NUM> can be configured to focus the light received from the LED <NUM> onto an external focal point in proximity of the input surface of the optical fiber <NUM> such that the divergence angle of the light propagating from the focal point to the input of the optical fiber substantially matches the numerical aperture of the optical fiber so as to allow efficient coupling of the light into the optical fiber.

In other embodiments, the optical fiber <NUM> can be optically coupled to the light source <NUM> using other mechanisms. For example, with reference to <FIG>, the light source <NUM> can be a laser diode <NUM> having a housing <NUM> in which an opening 54a is formed for receiving, e.g., via a friction fit, a fiber optic coupling <NUM> to which the optical fiber <NUM> can be coupled so as to receive light from the laser diode. In some cases, a flange (not shown) can be used to ensure that the proximal end of the fiber coupling <NUM> is securely coupled to the opening in the housing of the light source.

With reference to <FIG>, <FIG>, and <FIG>, the optical fiber <NUM> is disposed in the tube <NUM> such that a light-emitting segment 20c of the fiber is in substantial register with one or more of the openings <NUM> (e.g., opening 30a) in the distal portion 12b of the tube <NUM>. In other embodiments, the tube <NUM> can include a single opening <NUM> that is configured to receive light from the optical fiber. In this embodiment, the optical fiber <NUM> is a side-emitting fiber in which its light-emitting segment is angled at about <NUM> degrees relative to the axis of the optical fiber so as to direct the emitted light toward the opening 30a in the tube. At least a portion of the light emitted through the opening 30a passes through a portion of the surrounding tissue and can be monitored (e.g., visually and/or via an appropriate detector) to guide the nasogastric tube through the gastrointestinal tract.

The light emitted via the optical fiber <NUM> that passes through surrounding tissue can be externally detected and monitored, visually or via an appropriate detector. For example, as shown schematically in <FIG>, a camera <NUM> can be employed to obtain an image of the distal portion 12b of the tube <NUM> to discern the position of the tube within the gastrointestinal tract.

A variety of different fibers emitting light in a variety of different ways are disclosed. For example, <FIG> shows three different types of optical fibers <NUM>, <NUM>, and <NUM>, wherein only fiber <NUM> is covered by the present invention. The fibers <NUM> and <NUM> are further examples not covered by the present invention. The optical fiber <NUM> has a distal end 70a and light rays 70b passing through an inner chamber 70c are emitted an end region formed at the distal end 70a. Specifically, the light is emitted at a <NUM>-degree angle relative to a longitudinal axis of the fiber since the opening is slanted or formed at an angle. Likewise, the optical fiber <NUM> has a rounded distal light-emitting end 72a, and the light rays 72b passing through an inner chamber 72c are emitted at the distal end region 72a in a more dispersed pattern. Also, the optical fiber <NUM> has a substantially flat distal light-emitting end 74a and light rays 74b passing through an inner chamber 74c are emitted at the distal end 70a in a relatively parallel manner. Other optical fiber configurations can also be used, such as for example fibers that have multiple light-emitting segments that are distributed along their length, where each of the light-emitting segments can be positioned in substantial registration with one of a plurality of openings disposed in the distal region of the tube, as discussed in more detail below. With reference to <FIG>, in some embodiments, the optical fiber <NUM> can be disposable and hence can be removed, after use, from the light source <NUM>. The tube can be discarded as well.

Referring again to <FIG>, the illumination system can be configured as a nasogastric system that employs the tube <NUM> and the associated optical fiber <NUM>. The distal end 12B of the tube <NUM> can be positioned in the esophagus of the patient and can be guided to reach the patient's stomach. The optical fiber <NUM> is coupled to the light source <NUM> and hence light is conveyed from the light source <NUM> through the fiber to the distal end of the optical fiber and hence tube. A portion of the light emitted via the optical fiber can transilluminate at least a portion of the tissue surrounding the nasogastric tube <NUM>, thus revealing the position of the nasogastric tube, thereby allowing a user to monitor (visually or via a detector) the tube and hence to be able to safely guide the tube <NUM> to the patient's stomach.

In other embodiments, the optical fiber <NUM> can be configured to emit radiation axially at the distal end 20b, or the optical fiber <NUM> can include multiple light-emitting segments 20c each of which is placed in substantial registration with one of a plurality of openings <NUM> in the tube <NUM> so as to emit light along a plurality of different directions for external detection.

As noted above, in some embodiments, subsequent to the placement of the nasogastric tube <NUM> within a patient's gastrointestinal tract, the optical fiber <NUM> used for guiding the tube <NUM> into position can be safely and easily removed and the tube <NUM> can be used for its intended purpose, e.g., to administer nourishment and/or medicine to the patient or the compress the stomach, or any other purpose.

By way of example, <FIG> schematically depicts a partial view of an embodiment of a nasogastric system <NUM> which is not part of the present invention where the tube <NUM> includes an opening 102a at a distal end 12b, and an optical fiber <NUM> is disposed in the tube <NUM> so as to emit light <NUM> through the opening 102a. The optical fiber <NUM> includes a substantially flat light-emitting segment 20c at the distal end 20b, through which light is emitted from the optical fiber <NUM> and which is substantially aligned with the opening 102a to allow the passage of the emitted light <NUM> through the opening 102a for external detection. The divergence of the light <NUM> exiting the opening 102a ensures that at least a portion of the light exiting the opening 102a can transilluminate at least a portion of the surrounding tissue in a manner that allows monitoring the tube <NUM> as it is being deployed and guided within the patient's gastrointestinal tract. <FIG> schematically depicts another embodiment <NUM> in which the tube <NUM> seats or mounts an optical fiber <NUM> having a distal end 20b that has a rounded light emitting segment 20c that is disposed within the tube <NUM> such that the distal end 20b of the optical fiber is substantially aligned with the opening 102a to allow light <NUM> that is emitted from the opening 102a to transillumination the surrounding or adjacent tissue, thereby allowing tracking the gastrointestinal tube <NUM> within the patient's gastrointestinal tract.

<FIG> schematically depicts another embodiment of a nasogastric system <NUM> which is not part of the present invention. The system includes a tube <NUM> (e.g., a feeding tube) in which an optical fiber <NUM> is disposed. In the illustrated system <NUM>, the tube <NUM> includes a side opening <NUM>, <NUM> at a distal end 12b thereof and the optical fiber <NUM> includes a light-emitting segment 20c at a distal end 20b through which light <NUM> is emitted from the optical fiber. In this embodiment, the distal end of the optical fiber 20b is angled or bent so as to dispose the distal light-emitting segment 20c in substantial registration with the opening <NUM>, <NUM> in the tube.

By way of further illustration, <FIG> depicts yet another embodiment of a nasogastric system <NUM> that includes a tube <NUM>, which functions as a nasogastric feeding apparatus, having multiple openings <NUM> formed therein. The openings <NUM> include openings 132a, 132b, and 132c. The system also includes an optical fiber <NUM> that is mounted within the internal chamber 12d of the tube <NUM> and has s single light emitting segment 20c. The optical fiber <NUM> that is disposed in the tube <NUM> emits light <NUM> at a distal end 20b such that the emitted light <NUM> exits the tube <NUM> through the openings 132c so as to transilluminate at least a portion of the surrounding tissue and allows the nasogastric system and specifically the tube <NUM> to be externally monitored either visually or via a light-detecting device. In this embodiment, the other openings 132a, 132b can be used, for example, for administering nourishment and/or medicine to the patient, or to apply suction to the stomach.

<FIG> depicts still another nasogastric system <NUM> having a tube <NUM>, such as a feeding tube, having a plurality of openings <NUM> formed therein. The openings include openings 142a, 142b, and 142c. In this embodiment, the optical fiber <NUM> includes a plurality of light-emitting segments 144a, 144b, and 144c, each of which is in substantial register with one of the openings 142a, 142b, 142c. Similar to the previous embodiment, the light-emitting segment 144c is disposed at the distal end 20b of the optical fiber. The light-emitting segments 144a and 144b are disposed along the length of the optical fiber by removing a portion of the fiber's cladding. In this embodiment, the light-emitting segments 144a, 144b are in the form of circular bands of illumination, although in other embodiments other patterns of illumination can also be employ. The light emitting segments emit the light rays <NUM> that pass through the openings <NUM>.

<FIG> schematically depicts yet still another embodiment of a nasogastric system <NUM> according to the teachings of the present invention. The illustrated system <NUM> includes a tube <NUM> that includes a plurality of openings <NUM> formed therein. The openings include openings 152a, 152b, and 152c. The tube <NUM> seats or mounts an optical fiber <NUM> in the tube chamber 12d. The optical fiber has a distal end 20b that includes a light emitting segment <NUM>. The optical fiber <NUM> is positioned within the tube <NUM> such that the light-emitting segment <NUM> is disposed in proximity of the openings 152c that are formed in the distal portion 12b of the tube <NUM>. The openings 152c have mounted therein a window element <NUM> that can be formed of a material that is substantially transparent to the wavelength(s) of radiation emitted by the optical fiber. By way of example, the window element <NUM> can be formed of transparent silicone rubber. Further, in some embodiments, at least one of the windows <NUM> can function as a color filter to preferentially allow certain radiation wavelengths to pass therethrough. For example, the window can be formed from transparent silicone rubber impregnated with appropriate dye(s) to function as a color filter. The openings 152a and 152b formed in the distal region of the tube can be employed to administer medicine and/or nourishment to a patient. In other embodiments, the openings can be employed to apply suction to the patient's stomach, e.g., to compress the stomach.

<FIG> schematically depicts still another embodiment of a nasogastric system <NUM>, which includes a tube <NUM> and an optical fiber <NUM> disposed in the tube <NUM>. The tube <NUM> has a plurality of openings <NUM> formed therein. The openings include openings 162a, 162b, and 162c. In this embodiment, the tube <NUM> also includes a plurality of window elements 166a, 166b, 166c. The optical fiber <NUM> has formed at a distal end 20b a plurality of light-emitting segments 3002a, 3002b, and 3002c, where the light-emitting segment 164a illuminates the windows 166a, the light-emitting segment 164b illuminates the windows 166b, and the light-emitting segment 164c illuminates the windows 166c. The light <NUM> passing through the windows can transilluminate at least a portion of the lumen and surrounding tissue of the patient so as to be monitored externally (e.g., via visualization and/or detection). In some embodiments, the window elements 166a, 166b, 166c can function as color filters. Further, in some such embodiments, different windows can be configured as color filters for preferentially transmitting different colors of light. By way of example, in some embodiments, the windows 166a can preferentially transmit blue light, the windows 166b can preferentially transmit green light, and the windows 166c can preferentially transmit red light. By way of example, such an embodiment can be used with a light source emitting white light such that different segments of the nasogastric tube corresponding to the different windows can be visualized (or detected) in a different color.

<FIG> is a partial schematic view of a nasogastric system <NUM>, for example, a nasogastric feeding device, which is not covered by the present invention. The system <NUM> can include a nasogastric tube <NUM> in which an optical fiber <NUM> is disposed. A lens <NUM> is attached to a distal end 12b of the tube <NUM> and is in optical communication with a distal end 20b of the optical fiber <NUM> so as to receive light therefrom. The lens <NUM> includes a substantially cylindrical shaft 176a that extends to a hemispherical tip 176b. The hemispherical tip 176b presents a concave surface to the incident light and hence causes divergence of the incident light <NUM> such that at least a portion thereof exits the tissue surrounding the feeding tube to be monitored externally (e.g., via visualization or by a detector) for guiding the nasogastric tube through the gastrointestinal tract. In some embodiments, the lens <NUM> can be formed of a suitable polymer, such as, optical silicone rubber, PMMA (poly methyl methacrylate), polycarbonate, or glass. The nasogastric tube <NUM> further includes an opening <NUM>. In some embodiments, the opening <NUM> can be used to administer medicine and/or nourishment to the patient. In other embodiments, the opening <NUM> can allow the application of suction to a patient's stomach.

<FIG> is a partial schematic view of another embodiment of a nasogastric system <NUM>, e.g., a nasogastric feeding device, that includes a tube <NUM>, e.g., a feeding tube The tube <NUM> includes an opening <NUM> disposed in a distal region thereof. In this embodiment, rather than using an optical fiber to transmit light from a light source to the distal region of the tube, a light source <NUM>, e.g., an LED, is disposed in the inner chamber 12d of the tube <NUM> in proximity to the opening <NUM> such that at least a portion of the light emitted by the light source passes through the opening to be monitored externally (e.g., via visualization or via a detector) for guiding the tube through the lumen, such as for example the gastrointestinal tract. As shown schematically in <FIG>, a pair of conductors the 188a/188b can extend through the tube <NUM> to the light source <NUM> to transmit electrical power from an external source, such as an external voltage source (not shown) to the light source <NUM>. In this embodiment, the conductors 188a/188b are positioned within an electrically insulating sleeve <NUM>. Further, in this embodiment, the light source <NUM> is titled toward the opening <NUM> so as to optimize optical coupling between the light source and the opening. In this embodiment, the opening <NUM> can also be employed, for example, to administer medicine and/or nourishment to the patient, or apply suction to the patient's stomach, or for other purposes. Further, in some implementation of the nasogastric system <NUM>, rather than a single opening, multiple openings/windows can be employed, e.g., in a manner discussed above in connection with the previous embodiments.

<FIG> schematically depicts another embodiment of a nasogastric system <NUM> not covered by the present invention. The system <NUM> includes a tube <NUM>, e.g., a feeding tube, having an annular shape and a plurality of light sources <NUM> (e.g., a plurality of LEDs) formed in the housing of the tube (as shown), and are positioned circumferentially about the tube housing. The light sources can be optically coupled to the annulus portion of the feeding tube at a proximal end thereof. Similar to the previous embodiments, the light sources <NUM> can generate radiation in the visible, near-infrared or infrared portions of the electromagnetic spectrum. In this embodiment, the nasogastric tube <NUM> is formed of a material that is substantially transparent to the radiation emitted by the light sources <NUM>. By way of example, in some embodiments, the tube is formed of clear silicone rubber. While in some embodiments, the nasogastric device <NUM> can be configured as a nasogastric feeding device, in other embodiments, the nasogastric device <NUM> can be configured for other purposes, e.g., to compress the patient's stomach.

At least a portion of the light emitted by the light sources <NUM> is transmitted along the annulus of the tube and at least a portion of the light exits the annulus at it propagates from the proximal end of the tube to its distal end. Further, a portion of the light exits the annulus at the distal end thereof. At least a portion of the light exiting the annulus can penetrate through the surrounding tissue to be monitored externally (e.g., via visualization or otherwise), e.g., in a manner discussed above.

As noted above, a variety of light sources can be employed in nasogastric devices according to the teachings of the present invention. By way of example, in some cases, the light source can be a strobe light source (e.g., a strobe LED) that can provide repetitive flashes of radiation. Such flashes of radiation can be effective in capturing the attention of an operator of the device.

A nasogastric device according to the present teachings provides a number of advantages. In particular, it allows safe placement of a nasogastric tube in a patient's gastrointestinal tract without the need to expose the patient to potentially harmful radiation. This can be particularly advantageous for pediatric patients. Further, a nasogastric feeding device according to the present teachings is easy to use.

The illumination system of the present disclosure can be used to illuminate or transilluminate other types of lumens and areas within the patient. For example, the above embodiments are directed to illuminating nasal and gastric passages or lumens within the body. Likewise, the illumination system of the present disclosure can be used to illuminate lumens in other regions of the body, including cardiac passages or lumens, including for example, venous, aortic, and capillary lumens or passages. For example, the illumination system of the present disclosure can also be used to locate or visually show the location of a device inserted within a lumen in the heart region of the patient. <FIG> illustrates a lumen, such as an artery or a vein <NUM> that exists within the body of the patient. The vein <NUM> has an interior chamber 208a that seats a venous tube <NUM> suitable for use with the present disclosure. The tube <NUM> can be a catheter or the like that is sized and configured to be inserted and then eventually positioned within a cardiac region of the patient. The tube <NUM> can be inserted and positioned within the patient according to known techniques. As shown in the previous embodiments, the illumination system of the present disclosure includes an optical fiber <NUM> that is coupled to a light source <NUM>. The light source <NUM> can be remotely positioned external of the patient or can be disposed within the patient. The optical fiber <NUM> can be positioned within the chamber 12d of the tube <NUM> as it is inserted within one or more lumens <NUM> of the body. The optical fiber <NUM> emits light that is received from the attached light source <NUM> so as to illuminate the area at the distal end of the tube <NUM>, which can be formed of a substantially transparent material through which the light can exit the tube <NUM> and be observed externally to allow a doctor to determine the precise position of the tube as it navigates or passes through the body. The illumination system allows the doctor to visually determine the precise location of the tube, thus enabling the doctor to precisely locate and position the tube at a selected site within the lumen. In other embodiments, other portions of the tube <NUM> can be substantially transparent (such as the sections discussed above in connection with the previous embodiments) to allow passage of light emitted by the optical fiber <NUM> therethrough.

Once the tube <NUM> is properly positioned within the lumen <NUM> of the body, the optical fiber <NUM> can be removed from the chamber 12d of the tube <NUM>. A further medical device can then be inserted into the tube so as to perform a specific function or action at the surgical site. For example, the tube and illumination system can be employed during a cardiac catheterization procedure so as to assess heart function and diagnosis cardiac conditions. During this procedure, the tube or catheter <NUM> is inserted into a vein in the arm, neck or groin of the patient, and then the tube, with the assistance of the illumination system can be passed through the body to a selected site or location in the heart. The illumination system can be used to generate and emit light in the red light range so as to assist the doctor in determining the location of the catheter in the human body.

According to another practice, the tube <NUM> and the illumination system can be used as part of an angiography or arteriography procedure. During the angiography procedure, the tube or catheter <NUM> can be inserted into a lumen, such as vein or artery (e.g., femoral artery) of the patient, and the illumination system (e.g., light source <NUM> and optical fiber <NUM>) helps emit light within the artery to transilluminate the artery and surrounding tissue. The light can help the doctor locate or thread the tube to the proper location within the heart. Once the tube is properly located, the optical fiber can be removed from the tube. The angiography procedure can be used to help visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins, and the heart chambers. This is traditionally done by injecting a radio-opaque contrast agent into the blood vessel and imaging using X-ray based techniques such as fluoroscopy.

According to still another practice, the illumination system can be used to assist in angioplasty procedures. For example, the tube or catheter <NUM> can be inserted within a vein and the optical fiber <NUM> can be inserted within the tube. The illumination system via the optical fiber <NUM> emits light at the distal end of the tube to help locate the tube within the body. Once the tube is properly positioned, the optical fiber can be removed from the tube. Angioplasty is a minimally invasive, endovascular procedure to widen narrowed or obstructed arteries or veins, typically to treat arterial atherosclerosis. A deflated balloon attached to a catheter (e.g., a balloon catheter) is passed over a guide-wire into the narrowed vessel and then inflated to a fixed size. The balloon forces expansion of the blood vessel and the surrounding muscular wall, allowing an improved blood flow. A structural support, such as a stent, can then be inserted at the time of ballooning to ensure the vessel remains open, and the balloon is then deflated and withdrawn.

Claim 1:
A system (<NUM>, <NUM>, <NUM>, <NUM>) for illuminating a lumen within a body of a patient, comprising:
a tube (<NUM>) having a proximal end (12a), an opposed distal end (12b), and an internal chamber (12d), the tube (<NUM>) being configured for placement within the lumen of the body and comprising a nasogastric feeding tube (<NUM>) having a passageway for administration of nourishment to the patient; and
an illumination subsystem including:
an optical fiber (<NUM>) that is sized and configured to seat within the internal chamber (12d) of the tube (<NUM>); and
a light source (<NUM>) for generating light that is emitted by the optical fiber (<NUM>),
wherein a wall of the tube (<NUM>) is substantially transparent to light emitted by the optical fiber (<NUM>):
wherein the tube (<NUM>) has multiple openings (<NUM>) usable for administering nourishment and/or medicine to the patient,
and wherein the optical fiber <NUM>, when mounted within the tube (<NUM>) and when the light source (<NUM>) generates light, emits light at the distal end (12d) of the tube (<NUM>) so as to transilluminate the lumen and surrounding tissue; and
the optical fiber (<NUM>) has a rounded light-emitting distal end (72a, 20c).