Petitioner: Haag-Streit AG
`Petitioner: Haag-Streit AG
`
`Ex. 10(cid:20)(cid:25)
`
`EX. 1016
`
`

`

`(12) United States Patent
`US 6,596,016 B1
`(10) Patent N0.:
`Vreman et al.
`(45) Date of Patent:
`Jul. 22, 2003
`
`US006596016B1
`
`(54)
`
`(75)
`
`PHOTOTHERAPY OF JAUNDICED
`NEWBORNS USING GARMENTS
`CONTAINING SEMICONDUCTOR
`LIGHT-EMITTING DEVICES
`
`Inventors: Hendrik J. Vreman, Los Altos, CA
`(US); Daniel S. Seidman, Tel-Aviv
`(IL); David K. Stevenson, Los Altos
`Hills, CA (US)
`
`(73)
`
`Assignee:
`
`The Board of Trustees of the Leland
`
`Stanford Junior University, Stanford,
`CA (US)
`
`Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(21)
`
`(22)
`
`(63)
`
`(60)
`
`(51)
`
`Appl. No.: 09/551,946
`
`Filed:
`
`Apr. 19, 2000
`
`Related US. Application Data
`
`Continuation—in—part of application No. 09/094,231, filed on
`Jun. 9, 1998, now Pat. No. 6,350,275, which is a continu—
`ation—in—part of application No. 08/824,631, filed on Mar.
`27, 1997, now abandoned.
`Provisional application No. 60/049,230, filed on Jun. 9,
`1997.
`
`Int. Cl.7 .................................................. A61N 5/06
`
`(52)
`
`US. Cl.
`
`............................... 607/88; 607/91; 2/906;
`600/310; 600/315; 128/903; 128/904
`
`(58)
`
`(56)
`
`Field of Search ......................... 607/88, 91; 2/905,
`2/906; 128/903, 904; 600/310, 315
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`3,877,437 A
`4,441,049 A
`4,480,293 A
`
`4/1975 Maitan et a1.
`4/1984 Verstegen et a1.
`10/1984 Wells
`
`OTHER PUBLICATIONS
`
`Goethe, Why use homeopathic doses of phototherapy ?,
`Pediatrics, 98(2), pp. 283—287, 1996.
`Kang, J. et al., Double phototherapy with high irradiance
`compared with single phototherapy in neonates with hyper-
`bilirubinemia, Am. Jour. Perinatology, 12(3), pp. 178—179,
`1995.
`
`George, P et al., Ohmeda biliblanket vs wallaby photo-
`therapy system for the reduction of levels in the home care
`setting, Clinical Pediatrics, pp. 178—180, 1994.
`
`Primary Examiner—David M. Shay
`(74) Attorney, Agent,
`or Firm—Lumen
`Property Services, Inc.
`
`Intellectual
`
`(57)
`
`ABSTRACT
`
`A phototherapy garment contains a flexible backing
`material, a transparent liner, and a flexible printed circuit
`sheet containing surface-mounted light-emitting diodes
`(LEDs) positioned between the backing material and the
`liner. An infant is placed inside the garment so that the LEDs
`illuminate a large portion of the infant’s skin for photo-
`therapy. The LEDs preferably emit high-intensity blue light,
`suitable for treatment of neonatal hyperbilirubinemia or
`Crigler-Najjar syndrome. The LEDs are arranged in a
`densely packed array facing the liner and emit uniform, high
`intensity light. A power supply, which may be portable,
`supplies adjustable power to the LEDs, preferably pulsed
`with a duty cycle of approximately 10%, and preferably to
`overdrive the LEDs to maximize light output. A two-way
`communications device incorporated into the garment
`allows a physician or computer to control
`the garment
`remotely and gather relevant information periodically or
`continuously. The garment may also contain a feedback
`system with skin bilirubin sensors, so that the intensity level
`and duration of light therapy can be based on bilirubin in the
`skin, which is a reflection of the newborn’s serum bilirubin
`concentration. The garment can be of any type, including
`sacs, hats, sweaters, jackets, and rompers, and is lightweight
`and portable, allowing an infant to be treated at home, in the
`hospital, or when in transit. The garment provides high light
`intensity over a larger surface area of the newborn than
`allowed with existing techniques, thus providing very effi-
`cient phototherapy.
`
`(List continued on next page.)
`
`38 Claims, 5 Drawing Sheets
`
`50
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`/
`
`54
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`

`

`US 6,596,016 B1
` Page 2
`
`US. PATENT DOCUMENTS
`.
`4/1991 Prl§tash 6t a1~
`9/1991 Shlelds
`1/1994 Ignatius et 211.
`8/1994 Kremenchugsky et a1.
`
`590059108 A
`5,045,983 A
`5,278,432 A
`5,339,223 A
`
`10/1994 Bertwell et a1.
`5,358,503 A
`12/1997 Doiron et a1.
`5,698,866 A
`................... 2/905
`4/2000 Rosen et a1.
`6,045,575 A *
`6,145,551 A * 11/2000 Jayaraman et a1.
`............ 2/905
`
`* Cited by examiner
`
`

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`US. Patent
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`Jul. 22, 2003
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`Sheet 1 0f 5
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`US 6,596,016 B1
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`20
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`22.
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`22
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`w
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`m,III'IIIIIIIIIIIIIIII
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`6A
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`;/1
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`29
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`\—D
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`Fig. 1A 27
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`Power Supply
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`25
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`US. Patent
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`Jul. 22, 2003
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`Sheet 2 0f 5
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`'I'I'I'I'I'I'IIIIIIIIIIIIII ‘— 1 2
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`24
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`US. Patent
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`US. Patent
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`Jul. 22, 2003
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`Sheet 4 0f 5
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`US 6,596,016 B1
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`l
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`Monitoring
`System
`.. _. .. .1
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`45
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`Hospital
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`Home
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`Fig. 5
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`68
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`US. Patent
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`Jul. 22, 2003
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`Sheet 5 0f 5
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`US 6,596,016 B1
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`Fig. 7C
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`

`

`US 6,596,016 B1
`
`1
`PHOTOTHERAPY OF JAUNDICED
`NEWBORNS USING GARMENTS
`CONTAINING SEMICONDUCTOR LIGHT-
`EMITTING DEVICES
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`This application is a continuation-in-part of application
`Ser. No. 08/824,631, filed Mar. 27, 1997 now abandoned,
`which is herein incorporated by reference. This application
`is also a continuation-in-part of application Ser. No. 09/094,
`231, filed Jun. 9, 1998 now US. Pat. No. 6,350,275, which
`claims the benefit of US. Provisional Application No.
`60/049,230 filed Jun. 9, 1997, both of which are herein
`incorporated by reference.
`
`FIELD OF THE INVENTION
`
`This invention relates generally to treatment of neonatal
`hyperbilirubinemia (jaundice). More particularly, it relates
`to phototherapy methods and devices containing light-
`emitting diodes.
`
`BACKGROUND ART
`
`Approximately 60% of the four million infants born in the
`United States each year become clinically jaundiced.
`Jaundice, or hyperbilirubinemia, results from increased pro-
`duction and transiently impaired elimination of the pigment
`bilirubin. While most affected neonates recover rapidly,
`some infants show persistent high levels of unconjugated
`bilirubin. Such high levels can lead to kernicterus, a condi-
`tion involving deposition of bilirubin in the brain, which
`leads to deficits in cognition, neuromuscular tone and
`control, and hearing, and even death. The most common
`therapy for neonatal hyperbilirubinemia is phototherapy. It
`is estimated that as many as 400,000 neonates in the United
`States receive phototherapy every year.
`Phototherapy facilitates the transformation of unconju-
`gated bilirubin to compounds that are more easily excreted.
`Bilirubin undergoes in parallel
`three reactions:
`photooxidation, configurational
`isomerization, and struc-
`tural isomerization. Structural isomerization is the predomi-
`nant mechanism leading to bilirubin elimination from the
`bloodstream. Structural isomerization transforms bilirubin
`
`instantaneously and continuously into the more polar non-
`toxic pigment lumirubin, which is presumably the major
`bilirubin product excreted in newborns undergoing photo-
`therapy. The wavelength range generally effective for facili-
`tating bilirubin photoisomerization is approximately
`400—550 nm (violet to green), with light of a wavelength
`between 450 and 460 nm (blue) yielding maximal photoi-
`somerization. For general information on hyperbilirubine-
`mia and phototherapy, see for example the articles by the
`Provisional Committee for Quality Improvement and Sub-
`committee on Hyperbilirubinemia (American Academy of
`Pediatrics) in Pediatrics 94:558—565 (1994), Ennever in
`Clin. Perinatal. 17:467—481 (1990), and Maisels in Neona-
`tology.‘ Pathophysiology and Management of the Newborn,
`4th Edition, J. B. Lippincott Co., Philadelphia, p. 630—735,
`as well as the books by Volpe, Neurology of the Newborn, W.
`B. Saunders Co., Philadelphia, 1995, and Brown and
`McDonagh, Phototherapy for Neonatal Hyperbilirubine-
`mia: Efiicacy, Mechanism, and Toxicity, Year-Book Medical
`Publishers, 1980.
`The efficacy of phototherapy depends on four main fac-
`tors: irradiance (light intensity), spectral range (wavelength
`
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`or color), exposed skin surface area, and duration of expo-
`sure. Irradiance is a measurement of the light energy inci-
`dent on the skin, in units of nW/cmz/nm (power per surface
`area per wavelength). For a given light source power, the
`irradiance can be increased by decreasing the distance
`between the light source and the newborn. Lumirubin for-
`mation is not only wavelength-dependent, but is also stimu-
`lated by higher light intensities, as discussed in the article by
`G. Agati et al.
`in J. Photochem. Photobiol., B: Biol.
`17:173—180 (1993). Proper evaluation of phototherapy
`devices and techniques requires assessment of each of these
`four factors, as well as consideration of potential side effects.
`Phototherapy for
`treating hyperbilirubinemia is com-
`monly delivered using fluorescent lamps suspended above
`the neonate. However,
`these conventional phototherapy
`devices have substantial drawbacks. While fluorescent
`
`lamps output high-intensity light, they also generate signifi-
`cant heat (infrared radiation), which prevents their place-
`ment close to the infant, thereby decreasing the irradiance.
`Fluorescent light is of a broad spectral range, and cannot be
`produced in only the narrow wavelength range desired.
`Conventional phototherapy devices typically illuminate the
`newborn only from above, and do not
`therefore make
`optimal use of the available skin area. US. Pat. No. 3,877,
`437 to Maitan et al. describes an apparatus for simultaneous
`bilateral phototherapy of neonates, from both above and
`below, thus effectively doubling the exposed surface area of
`the infant. The apparatus uses fluorescent lamps and thus
`subjects the neonate to side effects discussed below.
`The use of fluorescent lamps for phototherapy leads to
`adverse side effects in many newborns. Such side effects
`include increased insensible water loss, hypothermia, loose
`and frequent bowel movements, tanning, and potential nasal
`obstruction by the eye pads required for preventing retinal
`damage. Furthermore, there are concerns that phototherapy
`using fluorescent lamps has potentially harmful effects on
`biological rhythms, and may increase the incidence of skin
`cancer in neonates subject to repeated treatment. For infor-
`mation on potential side effects of conventional photo-
`therapy treatment see the articles by Wu and Moosa in
`Pediatrics 61:193—198 (1978), Oh and Karecki in Am. J.
`Dis. Child 124:230—232 (1972), Bell et al. in J. Pediatr.
`94:810—813 (1979), Woody and Brodkey in J. Pediatr.
`82:1042—1043 (1973), Messner in Ped. Res. (Abstr.) 12:530
`(1978), Kemper et al. in Pediatrics 84:773—778 (1989), and
`Garden et al. in Arch. Dermatol. 121:1415—1420 (1985). In
`addition, overhead illumination with AC-powered blue light
`leads to discomfort and vertigo in nursery staff, as explained
`for example in the article by Wanamaker et al. in Lighting,
`Research, and Technology 7:19 (1975).
`Further drawbacks are introduced by the practical design
`of fluorescent
`lamps used for phototherapy. The bulky
`overhead lamps prevent unimpeded access to the baby and
`interfere with maternal-infant bonding. There is abundant
`literature regarding possible long-term harm stemming from
`disturbed maternal-infant bonding. For example, see
`Monogr. Soc. Res Child Dev. 64(3):67—96 (1999) and dis-
`cussion on pages 213—220; and J. Child Psychol. Psychiatry
`40(6):929—939 (1999).
`In the past, newborns typically
`remained in the hospital for at least three days, and hyper-
`bilirubinemia was treated aggressively during this time.
`Now, however, most newborns are discharged within 24 or
`36 hours, and bilirubin concentrations reach much higher
`levels before the problem is noticed. Such infants must be
`readmitted to the hospital for conventional phototherapy
`treatment, because phototherapy devices are not suitable for
`home use. Changing conditions demand phototherapy
`
`

`

`US 6,596,016 B1
`
`3
`devices that are less expensive and more flexible to use, and
`particularly those that can be used at home by parents.
`Several manufacturers have recently introduced fiberoptic
`phototherapy systems. Such manufacturers include Ohmeda
`(Columbia, Md.) and Fiberoptic Medical Products, Inc.
`(Allentown, Pa.). Typically, light from an incandescent ~150
`W tungsten-halogen bulb is delivered to a fiberoptic pad
`containing interwoven optical fibers having multiple scat-
`tering centers. The ends of all of the fibers are bundled
`together to form a cable into which the light source is
`directed. When the cable becomes too large in diameter, it is
`no longer convenient or feasible to use; thus the total optical
`power delivered to the pad is limited by the cable size. While
`the fiberoptic pads can be placed adjacent to the neonate
`(e.g. directly around the infant), the pad sizes and light
`intensities available with such systems are limited. For a
`given light source, enlarging the pad requires distributing the
`light over a greater area, thus reducing the irradiance. To
`achieve high levels of irradiance, manufacturers must com-
`promise the surface area by reducing the size of the pad,
`thereby exposing a relatively small surface area of the
`newborn to the light. Descriptions of fiberoptic phototherapy
`systems are provided in US. Pat. No. 4,234,907 to Daniel
`and US. Pat. No. 5,339,223 to Kremenchugsky et al. For a
`comparative analysis of two commonly used fiberoptic
`phototherapy devices, see the article by George and Lynch
`in Clinical Pediatrics, Mar. 1994: 178—180. The authors
`note the desirability of higher light intensities, and conclude
`that “in the past, perhaps too much attention has been paid
`to color and not enough attention has been paid to intensity.”
`Furthermore, Ennever et al.
`in J. Pediatr. 109:119—122
`(1986) suggest that “if a method for conveniently delivering
`phototherapy of much higher intensity were developed with-
`out attendant problems associated with high intensity, tung-
`sten filament sources, it could provide substantial improve-
`ment in the efficacy of phototherapy.”
`For further information and analysis of prior art light
`sources, see the articles by Pratesi et al. in Photodermatol-
`ogy 6:244—257 (1989), Donzelli and Pratesi in SPIE Pro-
`ceedings ofBiomedical Optoelectronic Devices and Systems
`2084:332—344 (1994), and Donzelli et al.
`in The Lancet
`346:184—185 (1995).
`Recently, devices have been developed that attempt to
`overcome the problems of low intensity and minimal surface
`area coverage of prior art phototherapy systems. Athin panel
`illuminator is disclosed in US. Pat. No. 5,005,108 to
`Pristash et al. Light is input to a transparent panel, conducted
`through the panel, and then emitted from one of its surfaces.
`The panel is flexible and may be shaped around a body part
`for optimum delivery of light
`to the required areas.
`However, this panel suffers from the same intensity problem
`as fiberoptic panels. The light is generated in a location that
`is a distance away from the location of its delivery to the
`skin, and the resulting power delivered is lower than desir-
`able for phototherapy applications.
`US. Pat. No. 5,698,866 to Doiron et al. discloses a
`uniform illuminator for
`local phototherapy using light-
`emitting diodes (LEDs) as a light source. LEDs provide
`significant advantages over fluorescent lamps or fiberoptic
`systems: narrow spectrum, high intensity at desired
`wavelengths, small size, relatively low cost, and ability to
`generate light in direct contact with the skin surface. The
`illuminator of Doiron includes a handpiece containing an
`LED array that is connected to a power source. The LEDs
`are fixed in a particular plane defined by the handpiece.
`While the device does provide a high irradiance, it covers
`only a very small region of the skin, and therefore cannot
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`provide the surface area exposure required for treating
`hyperbilirubinemia using total body phototherapy.
`A flexible pad containing diodes used for photo-thermal
`therapy is disclosed in US. Pat. No. 5,358,503 to Bertwell
`et al. Over a given skin region, the pads flexibility allows
`all of the diodes to be positioned with their longitudinal axes
`perpendicular to the skin. However, the device is not suitable
`for covering a large surface area of a neonate, which requires
`it to conform to the infant’s skin and therefore make sharp
`folds. The lens-type diodes used are also not suitable for
`supporting the neonate’s weight. Finally, the pad is intended
`to provide both heat and light, and provides no means for
`cooling the diodes or infant.
`There is still a need, therefore, for a phototherapy device
`that provides high irradiance to a large surface area of the
`neonate, is inexpensive, consumes relatively low power, can
`be used outside of a hospital, minimizes discomfort to the
`neonate and caregivers, operates at the desired wavelength
`range, and is completely safe for the neonate.
`
`OBJECTS AND ADVANTAGES
`
`Accordingly, it is a primary object of the present invention
`to provide a phototherapy garment that provides high irra-
`diance to a maximum surface area of a neonate, thereby
`providing for rapid reduction in serum bilirubin levels.
`It is an additional object of the invention to provide a
`phototherapy device in which light is generated directly
`adjacent
`to the neonate’s skin without overheating the
`neonate.
`
`It is another object of the invention to provide a photo-
`therapy garment that is lightweight and portable, allowing
`the neonate to be treated at home or while in transit.
`
`It is a further object of the invention to provide a photo-
`therapy garment that prevents light from reaching the neo-
`nate’s eyes, thereby eliminating the need for an eye shield
`and preventing nausea in nursery staff.
`It is another object of the present invention to provide a
`phototherapy device that provides light that is completely
`safe to the neonate and causes few if any detrimental side
`effects.
`
`It is an additional object of the invention to provide a
`phototherapy garment
`that
`is relatively inexpensive and
`consumes little power.
`It is another object of the present invention to provide a
`phototherapy garment that fully covers the neonate, thereby
`preventing discomfort and hypothermia.
`It is a further object of the invention to provide a photo-
`therapy garment that does not inhibit maternal-infant contact
`and bonding.
`It is an additional object of the invention to provide a
`phototherapy garment incorporating skin sensors that pro-
`vide feedback to control activation of the light-emitting
`diodes.
`
`is an object of the invention to provide a
`it
`Finally,
`phototherapy garment that communicates with a monitoring
`system using a two-way communications device, allowing
`remote control and recording of the garment’s operating
`parameters.
`
`SUMMARY
`
`These objects and advantages are attained by a photo-
`therapy garment for treating neonatal hyperbilirubinemia,
`Crigler-Najjar syndrome, and the like. The garment contains
`a flexible backing material, a liner sealed to the inside
`
`

`

`US 6,596,016 B1
`
`5
`surface of the backing material, and a printed circuit sheet,
`preferably flexible, secured inside a pocket between the
`backing material and the liner. The printed circuit sheet
`contains a printed circuit and a plurality of surface-mounted
`light-emitting diodes (LEDs) facing the liner, preferably
`arranged in a densely packed array and generating light that
`is uniform across the surface of the garment. For example,
`there may be approximately 16 LEDs per square inch. The
`array has a longitudinal direction and a transverse direction,
`and the garment is preferably flexible in the longitudinal
`direction and the transverse direction. Preferably, the printed
`circuit sheet covers a majority of the inside surface of the
`backing material. The LEDs emit light of a wavelength
`suitable for treating hyperbilirubinemia in neonates, such as
`420—500 nm, preferably between 440 and 470 nm. Portions
`of the backing material, liner, and flexible sheet may be
`removed to facilitate heat removal through the removed
`portions, and a heat sink material may also be provided.
`The garment may also include a power supply, preferably
`portable, in electrical communication with the printed circuit
`for supplying power to the LEDs. The power supply may
`include means for supplying power intermittently and means
`for overdriving the LEDs. Preferably, the LEDs are supplied
`with enough power to generate an irradiance of greater than
`30 yW/cmz/nm, and most preferably greater than 100
`MW/cmz/nm. The garment may also contain a communica-
`tions device, preferably wireless and two-way, for control-
`ling and recording the parameters of LED operation. It may
`also contain sensors for measuring skin reflectance, as an
`index for the serum bilirubin concentrations, or properties
`such as skin temperature, oxygen saturation, glucose blood
`level, and perspiration.
`Adjacent portions of the edge of the backing material may
`be joined together to define an interior space surrounded by
`the liner and in which a neonate is placed. Various garments,
`such as hats, sweaters, jackets, rompers, and sacs, may be
`formed. In these embodiments, the outer layer of the gar-
`ment is a flexible shell with the desired shape, and a liner is
`sealed to the inside surface of the shell, with the printed
`circuit sheet positioned in between.
`The present invention also provides a method of treating
`a neonate for hyperbilirubinemia including the steps of:
`providing a garment with a plurality of surface-mounted
`LEDs that emit light at a wavelength suitable for treating
`hyperbilirubinemia; covering a skin region of the neonate
`with the garment so that the LEDs face the skin region; and
`providing sufficient power to the LEDs to activate them.
`Preferably, the garment covers a majority of the circumfer-
`ence of the skin region that is being exposed to the light.
`Power is preferably provided to the LEDs intermittently,
`with a predetermined frequency and a predetermined duty
`cycle, which is preferably less than 50%, and most prefer-
`ably approximately 10%. The method may also include
`measuring the bilirubin level in the skin, which is related to
`the pigment’s concentration in circulating blood of the
`neonate. The jaundice level of the skin is used to control
`activation,
`intensity, and duty cycle of the LEDs. The
`method may also include controlling LED activation
`remotely. The method can also be used to treat a patient with
`Crigler-Najjar syndrome.
`BRIEF DESCRIPTION OF THE FIGURES
`
`FIG. 1A is a top plan view of a preferred embodiment of
`a phototherapy garment of the present invention.
`FIG. 1B is a cross-sectional view of the phototherapy
`garment of FIG. 1A.
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`FIG. 1C is a cross-sectional view of an alternative
`
`embodiment of the garment of FIG. 1A.
`FIG. 2 illustrates a portion of a single printed circuit sheet
`containing light-emitting diodes, used in the garment of FIG.
`1.
`
`FIG. 3A shows a single cell of light-emitting diodes used
`in an alternative embodiment of the invention,
`in which
`portions of the garment are removed to facilitate cooling.
`FIG. 3B is a cross-sectional view of the single cell shown
`in FIG. 4.
`
`FIG. 4 is a schematic illustration of a phototherapy
`garment incorporating a communications device.
`FIG. 5 illustrates placement of a neonate in a photo-
`therapy garment of the invention.
`FIG. 6 shows a light-emitting sac of the present invention.
`FIGS. 7A—C show alternative garments of the present
`invention.
`
`DETAILED DESCRIPTION
`
`Although the following detailed description contains
`many specifics for the purposes of illustration, anyone of
`ordinary skill in the art will appreciate that many variations
`and alterations to the following details are within the scope
`of the invention. Accordingly, the following embodiments of
`the invention are set forth without any loss of generality to,
`and without imposing limitations upon, the claimed inven-
`tion.
`
`The present invention provides a phototherapy garment
`used for treating neonatal hyperbilirubinemia (jaundice) and
`related conditions, such as Crigler-Najjar Syndrome. Any
`suitable type of garment is included within the scope of the
`present
`invention, with all garments constructed from a
`light-emitting fabric described below. The present invention
`enjoys many of its advantages due to its use of light-emitting
`diodes (LEDs) to deliver light directly to the neonate’s skin.
`The LEDs are very small, very durable, and long-lasting. As
`a result, the garments are portable, lightweight, comfortable,
`easy to use, and relatively inexpensive. LEDs deliver rela-
`tively high light intensity for their physical size and weight
`with a relatively low power consumption (e.g., 70 mW), and
`therefore have high efficiency (optical output power/
`electrical input power). They produce no harmful UV radia-
`tion and negligible heat (infrared).
`In particular, the present invention uses surface-mounted
`LEDs, also known as chip-type LEDs, and not the more
`common lens-type or lamp-type LEDs. Lens LEDs contain
`a relatively large (e.g. 9 mm length and 3 or 5 mm diameter)
`bulbous lens used to focus the light at a particular angle, with
`two electrical leads extending from the bottom of the diode.
`They are thus relatively bulky and difficult to mount on a
`flexible surface. In contrast, surface-mounted LEDs are very
`small (e.g. 3 mm><2 mm><1 nm) and are mounted with their
`largest face contacting the surface and the leads extending
`sideways, so that they can easily be connected in series.
`Surface-mounted LEDs are therefore very well suited for
`incorporating into the garments of the present invention.
`A preferred embodiment of a phototherapy garment 10 is
`shown in FIGS. 1A and 1B. Phototherapy garment 10 is
`made of a flexible backing material 12 that has an inside
`surface 14 and an outside surface 16. Lining inside surface
`14 of material 12 is a flexible liner 18, which has dimensions
`approximately equivalent to the dimensions of material 12.
`Liner 18 is made of a material that is substantially trans-
`parent to visible light, and particularly to the wavelength
`emitted by the light-emitting diodes described below. Liner
`
`

`

`US 6,596,016 B1
`
`7
`18 is sealed to material 12 only at particular locations, and
`not across its entire surface area. In FIG. 1A, liner 18 is fixed
`to material 12 at lines 20. For example, it may be crimped
`(heat-sealed), stitched, or molded to material 12. Sealing
`liner 18 to material 12 defines pockets between the two.
`These pockets are then used to secure a number of strips 22,
`which contain light-emitting diodes, to garment 10. If gar-
`ment 10 is intended to encircle a neonate completely, it has
`suitable dimensions such as 20 inches by 16 inches. Of
`course, the dimensions of garment 10 may vary as desired or
`with the size of the neonate.
`
`Preferably, material 12 and liner 18 are made of the same
`material and formed together. For example, they may be
`made of vinyl, silicone, or urethane. Because garment 10
`directly contacts the jaundiced neonate, it is highly desirable
`that garment 10 can be cleaned and sterilized. The material
`should therefore be impervious to the solution, solvent, or
`gas used for cleaning or sterilization. In addition, the seal
`between material 12 and liner 18 should be impenetrable to
`any potential cleaning agent so that it does not contact the
`LEDs or electrical circuitry sealed inside. Alternatively,
`material 12 and liner 18 may be coated with an anti-bacterial
`coating, such as Medigard, manufactured by the Hydrogiene
`Corporation of San Diego, Calif. Medigard is formulated to
`kill a wide variety of bacteria, is resistant to cleaning and
`sterilization processes, and has a reputed four-year killing
`period. It can be coated in such a way as to be impossible to
`detach or destroy when applied to materials. Alternatively,
`garment 10 may be disposable, thereby alleviating the need
`for cleaning and sterilizing the garment.
`Garment 10 contains strips 22 of flexible printed circuit
`sheets positioned between material 12 and liner 18. For
`example, strips 22 may be of mylar or other non-conductive
`material. Strips 22 contain printed circuits, such as copper
`traces, and surface-mounted light-emitting diodes 24. Pro-
`ducing printed circuit sheets and appropriate materials to use
`are known in the art. Strips 22 are secured to garment 10 by
`their placement in the pockets defined by backing material
`12 and liner 18. Strips 22 are preferably sealed inside the
`pockets to allow a thorough cleaning of garment 10, such
`that cleaning material does not contacting strips 22. The
`light-emitting diodes 24 have light-emitting surfaces 26, and
`strips 22 are located in the pockets with these surfaces 26
`facing liner 18, in which case the light-emitting diodes are
`said to be facing liner 18. While FIG. 1A shows sixteen
`strips 22, it is to be understood that any number of strips 22
`may be used. In addition, they need not be strips, but may
`be any shape of printed circuit material. For example, a
`single sheet of printed circuit material may extend across the
`entire surface area of material 12. Preferably, as shown in
`FIG. 1B, material 12 and liner 18 are molded around strips
`22 to form a smooth surface 19. For example, a urethane
`liquid may be cast around strips 22 and then cured until
`hardened. Liner 12 may also contain dispersants, i.e., par-
`ticles that help disperse light generated by LEDs 24 to make
`it more uniform.
`
`FIG. 1C shows an alternative embodiment of a garment
`30, in which the LEDs are positioned between a liner 32 and
`a backing material 34. Unlike in garment 10, liner 32 of
`garment 30 is not molded around the individual LEDs. Liner
`32 is approximately 1 mm thick, and does not conform
`closely to LEDs 36. Garment 30 still presents a relatively
`smooth surface to the neonate. In addition, a combination of
`the two embodiments represented by FIGS. 1B and 1C can
`be made. That is, each strip of printed circuit sheet can be
`surrounded by the cast silicon or urethane, and then this strip
`inserted into a pocket
`in a vinyl material.
`In this
`embodiment, individual strips may be replaced if necessary.
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
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`8
`Each strip 22 of garment 10 is further divided into
`individual cells 46, shown in more detail in FIG. 2. For ease
`of illustration, FIG. 2 shows only seven individual cells 46.
`FIG. 2 illustrates a strip of flexible printed circuit sheet 40
`containing a printed circuit 42 and an array of surface-
`mounted light-emitting diodes (LEDs) 44a, 44b, and 44c.
`LEDs 44a—c are preferably very small gallium-nitride-based
`LEDs that emit narrow-band blue light (450—490 nm), for
`example, broad-angle NSCB100 diodes from Nichia Chemi-
`cal Industries, Ltd. (Japan). These LEDs are characterized
`by superior intensity and efficiency in the blue region of the
`spectrum, which is known to be most effective for convert-
`ing bilirubin into products that are easily eliminated. LEDs
`44a—c are also very compact, having dimensions of only 3
`mm><2 mm><1 mm. Tightly-packed arrays of LEDs 44a—c are
`easily constructed, producing light that is uniform across the
`surface on which LEDs are fixed, rather than being localized
`to individual points. A density of 16 LEDs per square inch
`produces uniform light, but any suitable density may be
`used. Preferably, LEDs 44a—c are selected to have similar
`characteristics,
`i.e. similar spectral range and forward
`voltage, so that they produce light of substantially equal
`intensity. LEDs 44a—c contain two electrically conductive
`leads or pads that are connected to printed circuit sheet 40
`by a solder joint as known in the art.
`Each cell 46 preferably contains a number of LED strings
`connected in parallel. Within each string,
`the LEDs are
`connected in series. For example, in FIG. 2, each cell 46
`contains four strings connected in parallel, with each string
`containing three LEDs connected in series, such as LEDs
`44a, 44b, and 446. All of the LEDs in a single strip are
`supplied current through two electrical leads 48 and 49. Of
`course, any arrangement of LED strings and any number of
`LEDs per string is within the scope of the present invention.
`Referring again to FIG. 1A, a power supply 25 is elec-
`trically connected to a flexible electrical connector 27 at a
`connection 29. Flexible electrical connector 27 is connected
`
`in parallel to each of the two electrical leads exiting each
`printed circuit strip 22, such as leads 48 and 49 of FIG. 2,
`thereby connecting power supply 25 in parallel to each strip
`22. With this configuration, current is supplied to the printed
`circuits and all LEDs. All individual cells, such as cells 46
`of FIG. 2, are equivalent. Thus seven cells 46 are equivalent
`to 28 parallel strings of three LEDs in series. Athin electrical
`cable connects power supply 25