阅读说明：本技术 用于新生儿黄疸监测和管理的传感器和系统 (Sensor and system for neonatal jaundice monitoring and management ) 是由 迪特·威尔海姆·崔 李师豪 于 2020-01-10 设计创作，主要内容包括：本发明涉及一种用于黄疸的非侵入式光学监测传感器以及一种用于管理黄疸的系统。本发明的非侵入式方法的优点为在不受皮肤等组织中沉积的胆红素干扰的情况下测定血液中的胆红素水平,此光学传感器和方法可用于监测黄疸病情的进展及控制黄疸的光疗。当进行操作时,传感器在从处理器接收到适当的激活命令后,发出信号,产生一定波长分解光,分解胆红素。类似地,当由检测器测量时,在蓝色和绿色波长的光辐照后产生的光将对固定(组织附着)和移动(血液中)胆红素进行组合测定。然后,通过这些技术,脉冲测量结果随时间整合时,将提供固定(组织附着)胆红素浓度和移动(血液中)胆红素浓度的水平。这些计算将在处理器中完成。(The present invention relates to a non-invasive optical monitoring sensor for jaundice and a system for managing jaundice. The non-invasive method of the present invention has the advantage of determining bilirubin levels in the blood without interference from bilirubin deposited in tissues such as the skin, and the optical sensor and method can be used to monitor the progression of jaundice conditions and to control phototherapy for jaundice. In operation, the sensor, upon receiving an appropriate activation command from the processor, sends a signal to generate a wavelength of resolved light to resolve bilirubin. Similarly, the light produced after irradiation with blue and green wavelengths of light will perform a combined determination of fixed (tissue attachment) and mobile (in blood) bilirubin when measured by a detector. Then, with these techniques, pulse measurements, when integrated over time, will provide levels of fixed (tissue attachment) bilirubin concentration and moving (blood) bilirubin concentration. These calculations will be done in the processor.)

1. A jaundice monitoring sensor in contact with skin, comprising:

A) decomposition light source operated when sensor light source is turned off

B) A sensor light source for operating when the decomposition light source is turned off

C) Detector operating when sensor light source is on

Wherein if turned on, the dissociation light source emits light, undergoes dissociation and removes fixed (tissue attached) bilirubin from the skin in the optical path of the sensor light source, while the sensor measures the dissociation rate of the fixed (tissue attached) bilirubin; when the sensor light source is turned on, light received by the detector passes mobile (in blood) bilirubin rather than stationary (tissue attached) bilirubin, producing a sensor signal proportional to the mobile (in blood) bilirubin, thereby determining the blood bilirubin level.

2. The sensor of claim 1, wherein the resolving light source has a wavelength in the range of 400nm to 600 nm.

3. The sensor of claim 1, wherein the sensor light source has a wavelength range of 400nm to 600nm and is optimal at a bilirubin absorption peak of 450nm ± 20 nm.

4. The sensor of claim 1, wherein the detector detects light at a sensor light source emission wavelength or a bilirubin emission wavelength.

5. The sensor of claim 1, wherein light emitted by the sensor light source and received by the detector is transmitted through, or reflected by, or scattered by the skin or tissue, or a mixture thereof.

6. The sensor of claim 1, wherein light emitted by the sensor light source passes through tissue of the subject and is absorbed by bilirubin before being received by the detector.

7. The sensor of claim 1, wherein light emitted by the sensor light source is reflected and/or scattered by tissue of the subject and absorbed by bilirubin before being received by the detector.

8. The sensor of claim 1, wherein light emitted by the sensor light source excites bilirubin molecules and light emitted by the bilirubin molecules is received by the detector.

9. The sensor of claim 1, wherein the resolving light source and the sensor light source may be the same light source.

10. The sensor of claim 1, wherein the normalization light source and the signal light source and the decomposition light source operate continuously or in pulses.

11. The sensor of claim 1, wherein the sensor comprises a signal light source that is not in the optical path of the resolving light source.

12. The sensor of claim 1, wherein the sensor comprises a normalization light source and corresponding detector for normalizing signals from the signal light source and corresponding detector.

13. The sensor of claim 1, wherein the sensor comprises a temperature and/or pressure sensor for determining the temperature and/or heartbeat of the body.

14. A jaundice management system, comprising:

A) a sensor for contact with skin for jaundice monitoring, the sensor comprising: a resolving light source operating when the sensor light source is off, a sensor light source operating when the resolving light source is off, and a detector operating when the sensor light source is on, the detector being capable of sensing a signal proportional to moving (blood) bilirubin;

B) a control box for receiving signals from the sensors and calculating output control signals;

C) an illumination module receives the output control signal, and the output control signal controls the illumination power to change between 0 and 100% along with time.

15. The system of claim 14, wherein the signal from the sensor directly controls the light output power of the lighting module without a control box.

Technical Field

The present invention relates to a non-invasive optical monitoring sensor for jaundice and a system for managing jaundice. The non-invasive method of the present invention has the advantage of determining bilirubin levels in the blood without interference from bilirubin deposited in tissues such as the skin, and the non-invasive optical sensor and method can be used to monitor the progression of jaundice conditions and to control phototherapy for jaundice.

Background

Jaundice is a medical condition caused by the failure of the liver to clear bilirubin from the body. The accumulation of bilirubin can lead to yellowing of the skin, gums and sclera. Medical dysfunctions that lead to jaundice can be fatal to adults and can cause brain damage to newborns if left untreated. Subjects (e.g., adults or infants during neonatal care) can be screened for jaundice by detecting bilirubin levels in the blood of the subject by an invasive blood test.

Jaundice may also be detected by non-invasive methods, i.e. by visual methods or by analyzing the skin color of the subject using a device. The analysis by visual means is qualitative and depends on the skill of the health professional. Analysis using the apparatus may be performed by reflectance photometry or imaging. Percutaneous jaundice testers typically use reflectance photometry, usually on the forehead or sternum to determine bilirubin levels.

A problem with all non-invasive methods is that analyzing or imaging the yellow color of the skin indicates jaundice, but does not directly reflect bilirubin levels in the blood and changes in bilirubin levels in the blood.

Thus, there is a need for an accurate non-invasive method that directly reflects serum bilirubin levels while not interfering with pigmentation or bilirubin that has been deposited in the skin or tissue of a subject.

Disclosure of Invention

The invention provides a method for solving the problem that the conventional percutaneous jaundice tester cannot measure the level of bilirubin in blood. In contrast, current percutaneous jaundice testers measure the level of bilirubin deposited in the skin or tissue.

Thus, according to some embodiments of the present invention, a solution to the above-mentioned problem is provided and non-invasive optical sensors and systems are introduced to determine bilirubin levels in the blood. Advantageously, such a determination is not affected by bilirubin deposited in tissues such as the skin, and can more accurately determine bilirubin levels and changes therein in the blood.

A sensor for monitoring changes in the level of bilirubin in the blood is described. The sensor of the present invention includes a resolving light source, a sensor light source and a detector. In addition to the light source for optical measurements, the sensor of the invention also consists in a resolving light source. The decomposing light source is used for decomposing and photocatalysis to convert bilirubin into water soluble isomers/derivatives which can be more quickly removed from the skin and secreted by the body. Thus, the deposited bilirubin is removed in the optical path of the sensor light source and the result is therefore not affected by the deposited bilirubin but is representative of serum bilirubin.

Drawings

The following drawings illustrate some non-limiting exemplary embodiments or features of the invention.

Fig. 1A shows an optical sensor for jaundice monitoring in contact with the skin, which consists of a resolving light source that operates when the sensor light source is off and a sensor light source that operates when the resolving light source is off, the detector should operate when the sensor light source is on and sense a signal proportional to the moving (in the blood) bilirubin. There may be multiple light sources and detectors as shown in FIG. 1B.

FIG. 1C shows the split light source and the measurement light source combined together.

FIG. 1D shows different settings for bilirubin determination using the resolving light source of the present invention and without the resolving light source.

Fig. 2A shows the reflection mode of the sensor, where the light source and the detector are placed on the same side. After transdermal bilirubin breakdown, the sensor may measure bilirubin levels. Signals from decomposed and non-decomposed regions may also be measured, as shown in FIG. 2B.

Fig. 3 schematically shows a system for managing jaundice, which includes a sensor, a control box and a lighting module.

Figure 4 shows a flow of a sensor and control system for bilirubin determination and jaundice management.

With specific reference now to the details of the drawings, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the embodiments of the present invention. In this regard, the drawing figures make it apparent to those skilled in the art how the embodiments of the present description may be practiced.

Identical or repeated or equivalent or similar structures, elements or components appearing in one or more figures are generally labeled with the same reference numeral, optionally with one or more letters appended to distinguish similar entities or variants of entities, and are not repeatedly labeled and/or described. References to the aforementioned elements are implicit without further reference to the drawings or description in which they appear.

Dimensions and features of components shown in the figures are chosen for convenience and clarity of presentation and are not necessarily shown to scale or at true angles. Some elements or structures are not shown or only partially shown and/or are shown from different perspectives or from different perspectives for convenience or clarity.

Detailed Description

According to some embodiments of the present invention, the devices and methods provided herein enable non-invasive determination of bilirubin levels in blood by detecting bilirubin from tissue areas such as skin that is first illuminated by a resolving light source to remove transcutaneous bilirubin, also referred to herein as fixed (tissue attached) bilirubin. As shown in fig. 1A, the optical path of the sensor light source 5 is located within the optical path of the resolving light source 6. Advantageously, the sensor of the present invention is not affected by deposited bilirubin and provides a signal proportional to serum bilirubin. When the resolving light source 2 is turned on, the resolving light source 2 emits light, resolving and removing fixed (tissue attached) bilirubin from the tissue, for example the skin 1 in the optical path of the sensor light source 5. The resolving light source may be operated in a continuous or pulsed manner taking into account the photoisomerization parameters such as absorption and extinction coefficients, quantum yield, radiative lifetime, energy gap calculations, and zero and first order kinetic energies. The emission duration and frequency of the resolving light source will depend on the continuous or pulsed configuration of the resolving light source and the photoisomerization parameters. Fixed (tissue attached) bilirubin is removed or its removal rate is determined by performing an iterative and integration-based algorithm on a plurality of data points collected over a period of time by a single or multi-class detector, which data points coincide with serum bilirubin levels. When the resolving light source 2 is off and the sensor light source 3 is on, the bilirubin present in the optical path of the sensor light source is mobile (in the blood) bilirubin and the signal received by the detector 4 corresponds only to serum bilirubin. Since the depth of blue light into the skin is only about 1 to 2mm, the sensor of fig. 1 can have two separate light sources opposite each other. If the sensor of fig. 1 is mounted on the ear, in particular the outer ear, there are separate light sources at both positions of the outer ear. This arrangement allows deeper penetration of the tissue since the tissue of the outer ear is illuminated from both positions. The combined penetration depth of up to 4mm is greater than the thickness of the infant's outer ear, and therefore all of the fixed (tissue attached) bilirubin can be decomposed within the infant's outer ear. The method is not limited to ears but may be applied to fingers or toes or any other tissue.

This is an advantage over current non-invasive bilirubinmeters, where the signal is always the sum of fixed (tissue attached) bilirubin and mobile (blood in) bilirubin. Or in most cases, the signal reflects only fixed (tissue attached) bilirubin, adipose tissue, and other pigmentation. The effect of the source of the resolving light on the level of bilirubin in the blood is negligible. Even some blood or moving (in blood) bilirubin that has been resolved in the optical path of the resolving light source is replaced in a short time by blood flowing through the tissue. The present invention is an advance in the art to determine changes in blood bilirubin by introducing a new source of dissociation light within the bilirubin sensor.

As shown in fig. 4, when operating as such, the sensor, upon receiving an appropriate activation command from the processor, signals the resolving light source 2 to generate resolved light of a certain wavelength (e.g. 450 nm). The resolving light may be in transmitted light for the majority of the time the device is in contact with the skin or tissue to remove as much of the fixed (tissue attached) bilirubin as possible. The emitted light passes through the skin 1. The light passing through 1 may be collected by a detector 4. The pulse signal time is judged by the controller and the result is determined to be calculated, and then the bilirubin concentration is calculated and displayed by the controller, and the flow chart is shown in fig. 4. The resulting signal may be sampled by the control box. This process will be done in a continuous or pulsed manner and the resulting signal recorded over a period of time.

Once the integration process is complete, the processor sends another signal to the light source 3 to emit optical radiation at a second wavelength (e.g. 520nm) and, after a delay, a third wavelength (e.g. 470 nm). The emitted light travels the same path as the resolved light to a detector that measures the intensity of the illumination transmitted through the tissue or skin or outer ear. The resulting signal may be recorded.

To calculate bilirubin levels, the isomerization of bilirubin levels will first be determined by signal integration. The bilirubin is instantaneously isomerized into 4Z, 15E-bilirubin under the irradiation of photocatalytic light. The light pulse consists of decomposed light, blue and green wavelengths of light. The photoisomerization of bilirubin into water soluble 4Z, 15E-bilirubin was calculated by using femtosecond transient absorption spectroscopy and a method of anisotropy measurement by appropriate filters.

Similarly, the light produced after irradiation with blue and green wavelengths of light will perform a combined determination of fixed (tissue attachment) and mobile (in blood) bilirubin when measured by a detector. Since the proportion of mobile (in blood) bilirubin remains more or less constant, the ratio of bilirubin to 4Z, 15E-bilirubin will be the ratio to the fixed (tissue attached) bilirubin component. Since the attenuation of bilirubin to 4Z, 15E-bilirubin follows first order kinetics, stable bilirubin levels can be calculated. Then, with these techniques, pulse measurements, when integrated over time, will provide levels of fixed (tissue attachment) bilirubin concentration and moving (blood) bilirubin concentration. These calculations will be done in the processor.

In another embodiment of the sensor shown in fig. 1B, a plurality of light sources 2, 3 and detectors 4 are shown. The light source 2 is a resolving light source and includes a reference light source 3 having different wavelengths not within the absorption/fluorescence spectral range of bilirubin.

Also, in this embodiment, a plurality of detectors 4 will be used. The detector will be configured with different response ranges and sensitivities to detect transmittance, absorbance, and fluorescence signals, including resolved, sensed, and reference signals.

When the resolving light source 2 is turned on, the resolving light source 2 emits light, resolving and removing fixed (tissue attached) bilirubin from the tissue, for example the skin 1 in the optical path of the sensor light source 5. Thereby removing or measuring the removal rate of fixed (tissue attachment) bilirubin. When the resolving light source 2 is off and the sensor light source 3 is on, the bilirubin present in the optical path of the sensor light source is mobile (in the blood) bilirubin and the signal received by the detector 4 corresponds only to serum bilirubin. Because the depth of blue light into the skin is only about 1 to 2mm, the sensor of FIG. 1B may have two separate light sources and two sensor light sources opposite each other.

In another embodiment of the sensor shown in fig. 1B, a plurality of light sources 2, 3 and detectors 4 are shown. In fig. 1C, another embodiment of the sensor is shown, with the splitting light source 2 and the sensing light source 3 combined as one. In this embodiment, the dissociation light source 2 will first be activated to dissociate and clear bilirubin deposited in the tissue. The power and frequency will then be adjusted to the sensing light source to begin the determination of serum bilirubin in the blood. The combined light sources 2 and 3 will be operated alternately to remove bilirubin from the tissue 1 and to measure serum bilirubin in the blood. The sensor 4 will detect signals from the splitting light source 2 and the sensing light source 3, which in this case are combined into one light source.

In fig. 1D, another embodiment of a sensor 4 is shown, comprising an additional sensor light source 2 and the sensor 4, wherein the optical path 5 of the additional sensor light source is not in an area of tissue, such as the skin 1, which is decomposed by the decomposition light source 2. With this dual sensor configuration, the difference in fixed (tissue attached) bilirubin was measured between the tissue region irradiated with the resolved light and the tissue region not irradiated with the resolved light. This configuration also provides an indication of the ability of the body to remove bilirubin through differential calibration measurements, thereby providing information on the kinetics of fixed (tissue attachment) and mobile (in blood) bilirubin.

In fig. 2A, another embodiment of the sensor is shown, where the detector 4 and the light source 2 are placed on the same side of the tissue, e.g. the skin 1. The split light source 2 will first be activated to remove bilirubin from the tissue (e.g., skin 1) and then the sensing light source 3 and/or the reference light source 3 will be turned on in sequence to detect serum bilirubin. The detector 4 will detect signals from the same side of the tissue, e.g. the skin 1.

In fig. 2B the sensor comprises an additional sensor light source 3 and a sensor 4, wherein the optical path 5 of the additional sensor light source is not in the region of the tissue, e.g. the skin 1, which is decomposed by the decomposition light source 2. By placing this dual sensor 4 configuration on the same side as the light sources 2, 3, the difference in fixed (tissue attached) bilirubin is measured. This configuration also provides an indication of the ability of the body to remove bilirubin.

The stationary (tissue attachment) bilirubin and mobile (blood) bilirubin concentrations were recorded as a function of time. The change in fixed (tissue attachment) bilirubin may be slow due to the relatively slow kinetics of bilirubin removal from the skin. Thus, the fixed (tissue attached) bilirubin measurements provided by prior art non-invasive devices do not reflect changes in the blood bilirubin levels. The present invention overcomes this limitation by introducing a split light source.

The system and method of the present invention solves the problem of noninvasive jaundice management in newborns or children by determining the concentration of bilirubin levels in the blood of a subject.

In the above embodiments of the present invention, a sensor is described which is in contact with a tissue such as the skin of a subject.

The embodiments of the present invention overcome the following problems: bilirubin deposits in tissues such as the skin can lead to erroneous bilirubin determinations, resulting in excessive or insufficient levels of bilirubin in the blood of a subject.

In another embodiment of the invention, the skin-contacting sensor is configured with two sensor light sources, as shown in fig. 2B. One light source is in the optical path of the split light source and the other sensor light source is not. With this arrangement, the sensor light source and its corresponding detector within the resolving light source optical path will measure moving (in blood) bilirubin alone, and the sensor light source and its detector not within the resolving light source optical path will measure the sum of moving (in blood) and stationary (tissue attached) bilirubin. By subtracting the signals received by the respective detectors of the two light sources, the amount of fixed (tissue attached) bilirubin can be calculated.

Typically, the dissociation light source can be turned on most of the time to remove the fixed (tissue attached) bilirubin. The other splitting light source may be pulsed or turned on only for a certain time. For the assay, the resolving light source may be turned off and the measuring light source turned on. The measurements may be made at any regular or irregular interval, or may be made at the request of the user. The measurement time is typically very short, between microseconds and seconds. Multiple assays may be performed and the results processed, for example, to count medians or to statistically analyze the results. The measurement can also be performed when the decomposition light source is turned on. However, this is not preferred as resolving light may reduce accuracy or saturate the detector. The detector may also be used to determine the intensity of the decomposed light source.

The sensor of the present invention may comprise a proximity sensor. Proximity sensors can be used to monitor contact of the sensor with the subject's skin and provide warnings.

The sensor of the present invention may comprise a temperature sensor. Temperature sensors may be used to monitor the proper connection of the device and the health of the subject and provide warnings.

The sensor of the present invention may comprise a pressure sensor. The pressure sensor may be used to monitor the heartbeat and correct the signal from the light detection sensor, as well as monitor the health of the subject and provide warnings.

The combined signal of the temperature sensor and the pressure sensor can be used to confirm that the device is properly connected to the subject.

The sensor of the present invention may be contacted with the skin in a variety of ways, such as by pressure, or by a clip mechanism, bandage, strap, or by fixation (tissue attachment) to the skin with an adhesive or mixture thereof.

In general, the sensor of the present invention may contact the skin at any part of the body. The sensor is preferably mounted on the ear, finger or toe.

The sensors of the present invention may be in contact with the skin of a subject for a period of time varying from a few minutes to a few weeks. If used with infants, the sensor may be in contact with the skin on the first or second day after birth. In this early stage, there is no bilirubin deposition in the skin or tissue of the newborn. Advantageously, the resolving light source of the sensor prevents bilirubin from depositing in the optical path of the sensor light source, thereby allowing individual determination of moving (in blood) bilirubin or blood bilirubin and its changes. If the sensor of the present invention is in contact with the skin on the first or second day after birth, the resolving light source will prevent any bilirubin from being deposited in the optical path of the sensor light source, and therefore any changes detected by the detector receiving the light emitted by the sensor light source will be directly proportional to the change in bilirubin level in the blood measured in real time. The relative change in bilirubin measured as described above can be correlated with the absolute level of bilirubin in the blood of the subject using a two-point calibration as described below. First, the sensor of the present invention is attached to the neonate on the first or second day of birth and the detector signal is measured. Blood bilirubin was determined by the most advanced invasive method and the two values correlated. Second, blood bilirubin is measured on any of the following days, with the sensor signal being measured and the results correlated. The difference of the second sensor signal from the first sensor signal and the corresponding difference of the second bilirubin blood level from the first bilirubin blood level provide an absolute calibration of the sensor in terms of a change in sensor signal/blood bilirubin level. After calibration, not only the relative change in the subject's blood bilirubin level may be determined, but also the absolute change in the subject's blood bilirubin level.

In another embodiment of the invention, a light source for normalization or comparison is added. The standardized light source operates at a wavelength at which bilirubin does not absorb light. Thus, the standardized light source and its corresponding detector are not affected by bilirubin levels and variations thereof. The normalized light source and the corresponding detector signal should remain constant. However, small variations in the position of the sensor attached to the subject's skin may change the optical path, thereby changing the sensor output of the sensor light source. This variation can be corrected for by using the signal from the corresponding detector of the standardized light source.

Embodiments of the invention are not limited to infants and children, but may also include adults and/or animals (e.g., any living subject).

In a further embodiment of the invention, a system for jaundice control is described, as shown in fig. 3, including a skin contact phototherapy sensor of the invention, consisting of a discrete light source operating when the sensor light source is off, a sensor light source operating when the discrete light source is off, and a detector operating when the sensor light source is on, which is capable of sensing signals proportional to moving (in blood) bilirubin, a control box for receiving signals from the sensor and calculating output control signals, a lighting module receiving the output control signals, which controls lighting power to vary over time between 0 and 100%, a phototherapy module for managing jaundice is shown icterohepatitically in fig. 3, which includes sensing module 9 and phototherapy box 13, within sensing module 9, photodiodes 10 and L11 for monitoring fixed (tissue attached) bilirubin levels and moving (in blood) bilirubin levels, which sensing module 9 will communicate with light box 13 via communication method 12, which may display on a microphone eye contact with phototherapy box 13, or with microphone eye contact with microphone 20, which may be used to communicate with microphone eye contact with microphone 20, or with microphone 12, which may be used to communicate with microphone 12, 26, 12, c.

The light source for the sensor light source or the dissociation light source may be selected from a xenon flash lamp or a light emitting diode of a certain wavelength, a laser diode and a polychromatic light source. A bandpass filter may be added in front of the light source to further select the wavelength of the emitted light.

The sensing module will provide a change in the concentration of bilirubin or bilirubin in the body, thereby providing guidance or instructions to the phototherapy device to adjust the intensity of phototherapy for the subject, and notify the caregiver with a buzzer when a change in intensity occurs. In some cases, such as home care, camera and audio modules may be used, which may be connected to a computer/mobile (in the blood) phone for continuous monitoring of the subject in the light therapy box. The audio and video data may be analyzed by artificial intelligence to identify the patient's comfort during treatment.

In some embodiments of the invention, a reflectance photometry is used. Incident light from the sensor light source may be directed onto the tissue. The reflected light may be collected in at least one detector and the intensity of the reflected light may be measured. When bilirubin is present, the intensity may be reduced. As the concentration of bilirubin in the blood increases, the absorption from 400nm to 500nm will increase, resulting in a decrease in the intensity of the reflected light.

In some embodiments of the invention, a method of fluorescence emission of bilirubin may be used to determine the bilirubin concentration in the blood of a subject. Incident light from the sensor light source may be directed onto the tissue. The emitted fluorescence can be collected by a detector and its intensity measured. The measured intensity increases when bilirubin is present.

The detector may comprise a fluorescence detector such as a photodiode, spectrometer or camera. The light received by the detectors, such as photodiodes, spectrometers, etc., may include fluorescence from moving (in blood) bilirubin. A filter may be installed in front of the detector to select a particular wavelength, such as the peak wavelength of the fluorescence emission of bilirubin, that can reach the detector and block any other wavelengths, such as the excitation wavelength.

In some embodiments of the invention, the detector may be selected from the group consisting of a photodiode, a photomultiplier tube, a photoresistor, a Charge Coupled Device (CCD) sensor, a Complementary Metal Oxide Semiconductor (CMOS) sensor, a fluorescence detector, a filtered photodiode, a spectrometer, and a camera.

For a better understanding of the present invention, the following definitions are made.

In the context of the present invention, the term "fixed (tissue attached) bilirubin" means bilirubin deposited in tissues such as the skin.

The term "mobilized (in blood) bilirubin" means bilirubin in the blood and is transported by the flow of blood in tissues such as the skin. Mobile (in blood) bilirubin represents serum bilirubin, at a level similar to the level of serum bilirubin.

In the context of the present invention, the "dissociation light source" has the function of emitting light to dissociate and photocatalyze bilirubin into water-soluble derivatives which can be more rapidly removed from the skin and secreted by the body. The wavelength of the source of the decomposing light is generally the wavelength at which bilirubin is most efficiently removed from the body. In particular, the wavelength is between 400-600, covering the absorbance peak of bilirubin at 450 nm.

Preferably, the intensity of the light output is such that all of the fixed (tissue attached) bilirubin in the optical path of the resolving light source is removed, the resolving light source may be a light emitting diode (L ED) or a laser diode emitting continuous or pulsed radiation.

In the context of the present invention, a "sensor light source" emits light at the absorption wavelength of bilirubin. Typically, this wavelength is between 400nm and 500nm, with an optimum at the bilirubin absorption peak at 450 nm. The optical path of the sensor light source is in the optical path of the splitting light source. Thus, the absorbance at the sensor light source wavelength is due to mobile (in blood) bilirubin, since the effect of the resolving light source removes the stationary (tissue attached) bilirubin.

In the context of the present invention, a "detector" is a light detector, such as a photodiode, CCD or CMOS sensor, which produces an electrical signal, such as a current or potential, proportional to the received light of the sensor light source and the resolving light source. The sensitivity of the detector is in the wavelength range of 400-600 nm. Multiple detectors with different sensitivity ranges and response ranges may be used. The signal of one or more detectors in the sensing device reflects bilirubin deposited in the tissue and/or present in the blood.

In the context of the present invention, a "processor or microprocessor" is a computer or microcontroller unit that provides an electrical output calculated from an input received by a detector (e.g., a light detector). The electrical output may be an output of a display unit and/or an alarm unit, such as a speaker/buzzer, or may be an output transmitted remotely to other devices or stored on a data medium.

In the context of the present invention, a "standardized light source" operates at a wavelength at which bilirubin is not absorbing. It is used for standardizing the signal of the sensor light source. Thus, the standardized light source and its corresponding detector are not affected by bilirubin levels and variations thereof.