JPH0220252B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a skin-conforming sensor, and more particularly to a skin-conforming sensor which can be applied to a finger or rhinoplethysmography by non-invasive photoelectric measurements. It measures arterial oxygen saturation. A nosepiece optical sensor is disclosed that conforms to the physical shape of the external skin layer of the nasal septum.

BACKGROUND OF THE INVENTION Non-invasive monitoring of a patient's pulse is commonplace in medicine. One type of pulse monitoring device (plethysmograph) typically uses incandescent light bulbs or light emitting diodes (LEDs) to transillumate, or illuminate, areas containing large amounts of blood. The light source is attached to a fleshy tissue that perfuses blood, such as a fingertip. Light is emitted and shines through the tissue. The amount of light passing through this tissue is measured using a light sensor.
The change between the light emitted by the light source and the light received by the light sensor is caused by a change in the optical absorption of light by blood flowing through the transilluminated tissue. Broad spectrum visible light or narrow bandwidth light in red or infrared wavelengths can be used. The absorption of certain wavelengths is related to the oxygen saturation of the hemoglobin in the blood flowing through the transilluminated tissue. Fluctuations in light absorption caused by changes in oxygen saturation can be a direct measure of arterial oxygen content.

Based on this principle, instruments have been designed that use more than one wavelength to measure oxygen saturation and, in some cases, pulse rate.

A common problem with these types of oxygen sensors (oximeters) or pulse monitors (plethysmographs) is that their physical configuration does not match the patient's anatomy. A normal plethysmograph monitor has about a quarter of the finger on the same side of the bottom fleshy part of the fingertip.
It is a bulky, rectangular sensor that includes a light emitting diode and a light sensor spaced inches (about 6 mm) apart (see Figures 1A and 1B).
This design generally has artificial motion (motion).
The measured value is subject to distortion, which is called artifact.

Artificial motion is due to relative movement between the sensor and the patient's finger and changes in pressure within the tissue. This type of design also provides poor signal acquisition during periods of low blood flow in the irradiated tissue. Low blood flow occurs when blood vessels constrict and/or when the body has insufficient circulating blood volume.
These conditions commonly occur during periods of shock or hypothermia. Although this particular type of configuration has been used to measure oxygen saturation with good technical success, there are similar problems with loss of motion and pulse. Another problem with this design is that it is commonly attached by small hook and loop straps commonly known as products bearing the trademark "VELCRO." The design of this fixture makes it easy to detach from the finger, either accidentally or unintentionally. This causes the measurement to end prematurely and sometimes unexpectedly.

A clamp-type device is also used to measure a patient's pulse. It consists of one or more light emitting diodes near one side of a finger-like fleshy appendage. Light from the LED is received by light sensors located on opposite fleshy sides of the appendage (see Figures 1C and 1D). This type of construction generally consists of a small spring-loaded clip that attaches like a clothespin to the tip of a finger or similar appendage. This type of sensor mount is used not only in plessimography but also in oxygen meters. The advantage of a clamp-style sensor mount is that the light path passes through the entire nail and fingertip. This technique allows light to penetrate deeper into the patient's tissue than the simple single-sided surface sensors previously described.

This clamp-style sensor fixture is similar to single-sided sensor fixtures in that it often gives inaccurate readings due to strain caused by human motion, and is also prone to inadvertent removal. Has some drawbacks. Additionally, clamp-type sensor mounts have another significant drawback. That is, over a period of time, the spring loading pressure on fleshy tissue reduces blood flow to that tissue. This causes a loss of blood flow and therefore of the optical signal to be measured. To minimize this shrinkage effect of clamp-type fittings, the sensor must be adjusted or repositioned frequently, typically once or twice per hour. Due to this drawback, the structure of this sensor is not suitable for long-term continuous measurements.

We have already mentioned the phenomenon of artificial movement. Plethysmographs and oximeters operate on the principle that light absorption between a light source and a light sensor is the sum of two effects. The first effect is unaltered light absorption by stationary tissue. This may include irradiated skin, skin pigments, bones, nails, hair, and other components of tissue layers. Looking at FIG. 1E, there is shown an unchanging component 10 of light absorption from stationary tissue, which has a temporally constant amplitude.

A second effect of pulsating light absorption is the time-varying absorption by pulsating arterial blood flowing into the irradiated tissue layer. Looking at 11 in FIG. 1E, it can be seen that this is a quasi-sinusoidal pulsating wave riding on the top of the constant component 10 of light absorption. It is this second component that provides a direct and accurate measure of oxygen saturation in the pulsatile arterial blood flow.

Sensors with some mass or high aspect ratio are prone to relative motion between the light source, light sensor, and tissue due to small mechanical disturbances. This relative motion creates a concomitant variation in light transmission from the light source to the sensor, thus greatly distorting the light absorption measurements. When this motion occurs, variations in light transmission become a false indicator of light absorption. Such absorption errors ultimately result in corresponding errors in oxygen saturation measurements, all due to discontinuous contact due to relative motion between the light source, optical sensor, and tissue, as well as other causes. An example of such varying motion is shown as component 12 in FIG. 1E.

In FIG. 1E, the sensor has been transiently moved from the exact location where it was held.
The sensor moves due to the high inertia caused by its substantial mass and poor compliance with the supporting tissue. Movement of the finger by the patient or some disturbance causes relative movement between the sensor and the finger. The change in light transmission caused by this motion appears as a change in "light absorption" with time, shown as component 12 in FIG. 1E. Measuring devices designed to monitor optical absorption can detect optical data introduced into the sensor by the relative movement of the sensor and by blood pulsations, which the device is designed to analyze. cannot be distinguished. Confusion in the logic of the device will inevitably result in inaccurate analysis of the data from the oximeter, and thus erroneous measurements of oxygen saturation.

It will be appreciated that if the sensor has a significant mass relative to the finger and is not compliant with the finger, artifacts will occur virtually every time the patient moves. Recalling that the patient may be unconscious and/or moving, this body movement was what generated the artifact 12 in Figure 1E, for consistent and accurate measurements. This is a serious obstacle.

The reader will note that the graph in Figure 1E illustrates the problem to be solved. Of course, the act of inventing involves the ability to identify a problem to be solved. Therefore, insofar as this identification is novel, we claim it to be an invention in recognition of the specificity of the problem.

During periods of severe physiological strain, e.g. hypotension, hypothermia, and shock (hypoperfusion), the body's response is to divert blood flow away from the limbs and surrounding areas (skin surface) to divert blood from the central vital organs (e.g. the brain). It is the constriction of blood vessels (vasoconstriction) to maximize blood flow to the heart, liver, etc.).

The internal carotid artery is the main blood vessel that carries blood to the brain.

The nasal septum is the location of the terminal branches of the internal carotid arteries, the anterior and posterior ethmoid arteries. The nasal septum is
This is the final position in the body where this region is supplied with an abundant blood supply (to warm the incoming air) and where the branches of the carotid artery (including the anterior and posterior ethmoid arteries) undergo vasoconstriction under tension. Because it is recognized as an excellent place to monitor blood flow to the brain.

Doctors use surface-mounted optical pulse sensors (plethysmography) and optical oxygen saturation sensors (oximeters).
They have been used with great success in healthy patients, but with less success in critically ill and seriously injured patients. These surface sensors use two basic forms. The first form (Fig. 1) is a hook and loop fastener (e.g.
It consists of a small box-shaped sensor that is attached to the patient's finger by a product sold under the trademark ``VELCRO''. This design can suffer from unreliable measurements due to vasoconstriction and artifacts.
Artifacts that give rise to erroneous measurements result from relative movements between the sensor and the interrogated flesh, and artefacts can be induced by voluntary and involuntary movements. Artificial motion causes relatively large measurement errors when the desired pulse signal is very small during vasoconstriction.

Vasoconstriction is the narrowing of blood vessels, thereby reducing the amount of blood flow to the tissues they serve.
Vasoconstriction commonly occurs when the patient suffers from trauma, an accident, an infectious disease,
or occurs when physiological shocks result from surgical complications. Reductions in blood flow also occur when anesthesiologists are carefully creating very low blood pressure to minimize bleeding for certain surgical procedures. During vasoconstriction, there is too little blood for surface sensors to take measurements. As a result, the optical pulse signal is reduced and the influence of human motion errors becomes relatively large.

A second surface sensor configuration (FIG. 2) used to measure pulse and oxygen saturation consists of a spring-loaded clip shaped much like a clothespin. The sensor includes a light source on one side of the clip and a photodetector on the other side to measure the light absorption during transillumination by blood flow in the tissue between the two sides of the clip. . This second form is usually more effective than the first because the optical path penetrates much deeper through the nail and fingertip than the surface sensor (Figure 1), but In critically ill patients coupled with confinement spring pressure, vasoconstriction often results in pulse amplitudes that are insufficient to reliably measure pulse or blood flow. Therefore, even deep penetrating surface sensors may not be effective in critically ill or critically ill patients.

Statement of the Problem (Rhinoplethysmography) The reader will notice that the disclosed invention identifies the problem to be solved. The act of invention involves the ability to identify a problem to be solved. Therefore, as long as this identification is new,
We hereby claim that we have recognized the nature of this problem and that our invention lies in its solution.

The problems posed by the invention disclosed herein are: (1) direct non-invasive continuous measurement of oxygen levels in the cerebral blood flow of critically ill patients; (2) pulse rate of critically ill patients; There is a need for an accurate and constant monitoring device that provides an immediate indication of the adequacy of the oxygen content of the blood circulation in a patient.

SUMMARY OF THE INVENTION A sensor is disclosed for transilluminating a blood-perfused portion of a flesh area and measuring light absorption during the transillumination. Although this sensor is preferably attached to a fingertip, any finger or other blood-perfused tissue will work. The sensor adapts to the shape of the skin layer of the blood-perfused part of the flesh in which it is placed. The sensor is mounted on at least one flexible substrate.

The substrate comprises a first end for placement on one side of the flesh portion to be transilluminated and a second end portion for placement on an opposite opposing side of the flesh portion to be transilluminated. or it may be two separate substrates, in which case one substrate is placed on one side of the flesh to be transilluminated and the other substrate is located on one side of the flesh to be transilluminated. placed on the opposite side.

A light source is attached to the first end or the first substrate and a light sensor is attached to the second end or the second substrate. The single flexible substrate may be elongated and may be provided with an adhesive. The sensor is suitably windowed to allow light to take a path through the finger. If a flexible strip is not used, the two ends are aligned to direct the emitted light through the blood-filled skin and the skin is secured. If no adhesive is used, the sensor substrate may be non-intrusively fixed to the skin layer of the flesh to be transilluminated by means of a non-adhesive agent such as gauze.

When the sensor is fixed with adhesive, the effect of the light source and light sensor being integrated into the adhesive fastener is that they can effectively become part of the skin. The resulting device resists accidental dislodgement and avoids constriction of internal and external blood vessels. Most importantly, due to the small mass of the sensor itself and its conformance to the skin, movements, local forces, and the resulting poor contact between the light source, the light sensor, and the skin are avoided. This feature eliminates common disturbances associated with conventional plethysmograph and oximeter operation.

The present invention provides non-intrusive and reliable monitoring of vital signs in patients requiring intensive care to prevent damage to vital organs or reduction in vital capacity. directed towards doing. A nosepiece sensor is disclosed that measures light absorption during transillumination of a portion of the nasal septum perfused by ethmoid artery flow. The optoelectronic components, namely the light source and the light sensor, are embedded in a flexible adhesive substrate that is divided into two arms. This board is also provided with signal connections leading to the measuring device. One arm of the bifurcated substrate is attached across the nasal septum. The entire device is designed to orient the optical components to align the light source and sensor across the patient's nasal septum.

At least one light source is embedded in one arm. The light source conforms in plan to the shape of the substrate and is arranged to conform to the external nasal skin layer while emitting light through the nasal septum. At least one optical sensor embedded in the other arm also receives light adapted to the exterior surface of the nose and transmitted through the nasal septum.

Transillumination of the blood-filled portion of the nasal septum provides information such as the oxygen saturation of the hemoglobin in the blood stream, the amount of individual pulsatile blood delivered, and the rate and periodicity of the blood pulsations.

One object of this invention is to disclose a device for transilluminating blood perfused tissue with an interrogation optical path between a light source and a light sensor. According to this aspect of the invention, a light source and a light sensor are separately attached to opposite ends of an electrical or other signaling connection that is long enough so that the ends face each other from opposite sides of the tissue. There is. The light source and light sensor attached to a common flexible strip can therefore be fixed to the skin by adhesive so that the light source and sensor transilluminate the desired portion of the blood-perfused tissue currently facing. can. The adhesive attachment disclosed herein allows the device to completely conform the device elements to the patient's skin, thereby eliminating artificial movement. Therefore, optical absorption measurements and analysis for oxygen saturation determination based thereon become more accurate and less sensitive to injury.

It may also be possible to use separate fittings for the light source and light sensor with or without direct adhesive, which may be useful in certain applications, such as the hands of premature babies. That would be convenient. Indirect adhesive attachments, such as gauze wrapped around the hand and secured with adhesive tape, have also been used. However, single strips generally facilitate alignment and are preferred.

Another advantage of the invention is that the plastic flexible adhesive strip is attached onto the end of the fingertip rather than around the finger. This prevents restriction of blood flow to the tissue to be transilluminated and measured. The only slight pressure exerted on the patient by the device of the invention is applied locally to the patient at the skin layer in question directly holding the light source and light sensor. There are no local forces exerted on the flesh to be transilluminated. In short, this flexible adhesive strip does not constrain the blood-perfused flesh. Therefore, the blood flow in question is not disturbed.

Another advantage of the disclosed invention is the intimate attachment of the light source and light sensor to the skin. This suppresses accidental withdrawal. A sensor is disclosed that effectively becomes part of the affected area and is not subject to natural rejection, as may occur when a patient consciously or unconsciously attends to and resists the touch of a large foreign body attached to the skin. ing.

Another object of the invention is to disclose a method for making the device. In assembling the device of the invention, the light source and the light sensor are mounted on the substrate and both are constructed of small dimensions to accommodate differently flexible adhesive strips of small length and breadth. This method also uses sequential layers of surgical tape, opaque vinyl, and optical filters. A perforated opaque vinyl and finally a transparent adhesive layer are then placed over the entire optical sensor.
The result is a simple flexible adhesive strip device that adapts to the shape of the blood-perfused meat, ie the finger, with regard to blood flow.

Another advantage of this invention is that it is completely disposable and therefore hygienic. The resulting device is non-invasive, fully conforms to the skin, and provides minimal disturbance to the patient's movement and tactile sensation.

Another advantage of this invention is that the anterior ethmoid artery (a branch of the main artery supplying blood to the brain)
It can be continuously monitored and measured for volume, pulse rate and periodicity. Since the brain is one of the last organs to be denied blood in a critically ill or critically ill patient, this device is currently of use in providing critical information for patient treatment even under the most urgent conditions. It fills a need.

Another advantage of this device is that it is possible to monitor critically ill or critically ill patients who are already on a ventilator to ensure that the ventilated oxygen is reaching the brain. . Among other symptoms, instantaneous and accurate diagnosis of arterial blockage is now possible.

Another advantage is that the disclosed invention allows simultaneous monitoring of critically ill patients for arterial oxygen saturation and pulse rate, periodicity and amplitude.
Using instantaneous, simultaneous, and accurate measurements of a variety of vital signs, physicians can compare measurements according to the disclosed invention to aid prognosis and identify trends.

Another advantage of this device is that even under severe physiological conditions, the physiological housing in which the sensor is seated remains constant, providing an excellent monitoring location. The main function of the nose for the human body is to warm and moisten the inhaled air. The humidification function of the nose ensures an adequate blood supply even under severe physiological stress and vasoconstriction (discussed above) that commonly interfere with conventional surface plethysmographs and oximeters. Therefore, the nasal septum is an ideal location to take continuous and constant measurements of pulse rate and arterial saturation.

Another advantage of this invention is that the sensor is attached to the skin layer of the nasal septum without violating or blocking the blood of the anterior and posterior ethmoid arteries to be interrogated.

Another advantage of the disclosed invention is that the patient's body of a critically ill patient does not need to be exposed to the risk of being stung and infected or otherwise making the patient's condition even more dangerous.

Another advantage of the disclosed invention is that oxygen saturation in the anterior and posterior ethmoid arteries can be measured directly rather than indirectly. This ability to measure the oxygen content of the blood at all times facilitates early diagnosis of critical conditions in life support systems and allows for instantaneous responsive treatment of critically ill patients.

Another object of the invention is to disclose a method for manufacturing a nosepiece sensor. In the assembly of the device of the invention, the light source and the light sensor are embedded in a flexible plastic substrate, all of which are configured to very small dimensions, so that the sensor conforms to the skin shape of the patient's external skin layer. Adapt. The assembly process involves successive layers of attachment. The result is a device that is easily attached to the patient's nose.

Another advantage of the disclosed external nosepiece sensor is that
The ability to receive critical life support signals instantly and accurately without competing for critical locations through the nose. Interference with cannulae, tubes and detection devices in the nose is avoided.

Another advantage of the disclosed nosepiece sensor is that critical life support information can be accurately obtained from a critically ill patient by a person or a professional with little training or expertise.

Another advantage of the disclosed invention is that blood flow in critically ill patients can be measured with less risk of measurement errors due to artificial movement, and the foam layer between the adhesive and the substrate prevents artificial movement. The goal is to provide a tight, pressure-free skin seal.

Another advantage of the disclosed invention is that the foam layer between the adhesive and the substrate provides a light-tight seal between the skin and the sensor, thereby shielding the components and thereby measurements from harmful ambient light. It is to protect from influence.

Another advantage of the disclosed invention is that the opaque photographic coating applied to the foam/adhesive side of the flexible substrate
The purpose is to prevent measurement inaccuracies by reducing light refraction and reflection. The opaque photographic coating further provides protection from ambient light reaching the components.

Another advantage of the disclosed invention is that measurements of carotid blood flow through the ethmoid space are more accurate when measurements are made at a measurement location in the external skin layer of the nose than when made at a location in the internal nasal skin layer. It is to become.

Another advantage of the disclosed invention is that one size detection strip can be universally applied to the human nose. Human nostril dimensions, shape,
In contrast to the highly variable surface contours in question, the size and shape of the nasal bridge area of the human nose is relatively constant.

Other objects, features and advantages of the present invention will become more apparent with reference to the accompanying drawings.

Detailed Description of the Adopted Embodiment In the following description, the configuration of the sensor device 10 will first be described. We then describe the attachment to the blood-filled skin being examined.

Looking at FIG. 3A, we see that the two substrate parts 14, 24
is illustrated. A light sensor is attached to part 14. Portion 24 is fitted with a light source according to the invention. Referring to FIG. 3B, the light source will first be described.

The light emitting diodes 25 and 26 are attached to the substrate 27 with an adhesive, such as by bonding them with a conductive epoxy adhesive.
Fixed. Microcircuit configurations allow the use of light emitting diodes in very small dimensions. The reader will see that such a diode is fitted into a thin layer which is then fixed to the surface of the substrate 27.

In terms of dimensions, the substrate 27 is typically 4 mm x 6
mm, but other such dimensions can also be used. An electrical connection 28 is used;
It consists of a pair of light emitting diode drive conductors with a common ground.

Turning to FIG. 3C, the photosensitive portion of device 12 is shown. This photosensitive portion includes a substrate 17, an electrical connection 18, and a photosensitive surface 19 bonded to the plate 17.
It is made up of Again, dimensions are given that give the device a low profile and aspect ratio.

It should be apparent that the electrical connections disclosed herein may take other forms. For example, if the devices disclosed herein are to be mass produced, an integrated chip or thin film structure may be desirable.

In the embodiment adopted as of the date of this disclosure, the device is covered on the photoactive side with a transparent epoxy layer. We have adopted a transparent layer of epoxy on the structure of Figure 3B for insulation and light transmission, and a red layer on the substrate 17 of Figure 3C. The optical sensor is protected from ambient light spectrum outside the desired red and infrared wavelengths.

The sequential structure of the selected embodiment of the invention is best illustrated in FIG. 2C. As can be seen from FIG. 2C, the sensor boards 14, 2
The photoactive element 4 is fixed on the non-active side to an opaque vinyl strip 30 with an adhesive surface 32 . Similarly, a porous flexible adhesive tape is on top of the opaque vinyl strip 30 and a porous flexible tape layer 3
4 is provided with an adhesive surface 35. Looking at FIG. 2B, it can be seen that the tape 35 is elongated and has a chimney shape. That is, the distal ends of the shape are relatively wide and the intermediate end connections are narrow, so that the structure is suitably rounded. This configuration has been found to be particularly suitable for attachment to a finger.

When the light effecting elements 14, 24 are attached, 3
A second opaque vinyl tape is placed over the photoactive element at 7. The tape has a downwardly exposed adhesive layer 38 to capture the light source substrate and the photosensor substrate between strips 30 and 37.

The strips 37 are each provided with an opening 40, 41. These apertures allow light to pass through. At the same time, the thickness of the photoactive substrate is adapted to the total thickness of the flexible adhesive strip to which the attachment takes place. The photoactive substrate captured in this way is ideally tactilely indistinguishable from the flexible adhesive strip itself.

Finally, a layer 45 of transparent polyester with double-sided adhesive coatings 46, 47 is placed over the central narrow length of the flexible adhesive strip. This allows the passage of light and ensures intimate adhesion of the light sensor to the skin and the flexible adhesive strip.

The protective layer 50 of peel tape protects the entire article during manufacture and before use.

As will be appreciated, both the flexible adhesive strip layer 34 and the peel tape layer 50 are given the form of elongated strawberries. The remaining tape elements disclosed herein have a narrow rectangular overall shape that spans the entire length of the flexible adhesive strip.

Turning to FIG. 4, the invention is shown attached to a fingertip. Briefly, the distal portion rests on and surrounds the perfusion finger.

Light is emitted and penetrates the blood-perfused finger.

It should be noted that this is the configuration adopted for use with the tips of the fingers; other configurations may be appropriate for toes or other appendages such as the hand or foot. Might happen.

Additionally, structural changes could optimize the sensor for use with premature babies where the use of tape would be harmful to the skin. By eliminating the adhesive layer facing the tissue, a sensor is created that can be wrapped in place using a method suitable for such small children.

Additionally, this disclosure finds a suitable location on the skin of the nasal septum overlying the carotid cavity.

Returning to the drawings, Figure 5A, Figure 5B, Figure 6A
6B, the device of the invention consists of a substrate 116, bifurcated substrate arms 117, 118, a set of optoelectronic components 119, 120, and other layers.

The preferred embodiment is described as having optoelectronic components aligned and attached to opposing nose pad arms 117,118.

Referring now to FIGS. 7 and 8, substrate 116 is made of a flexible plastic composition that has some degree of elasticity. The side to be attached to the foam is coated with an opaque photographic layer 142. A thin spongy foam layer 148 is applied over the opaque photographic coating 142. Spongy thin foam layer 1
A medical adhesive layer 140 is attached to 48 . Substrate 116 has an opening 125 to allow light to pass through.

When the device of the disclosed invention is placed on the human nose as shown in FIGS. 6A and 6B, the substrate 116
fits snugly against the lateral bridge of the nose, and the two nose pad arms 117, 118 are attached to the lateral surfaces 128, 118 of the nose, respectively.
I sit firmly on 129. Arm parts 117, 11
8 is held in place with adhesive.

The adhesive layer 140 allows the arm to conform to the nasal septum without occluding the blood flow to be interrogated. Arm portion 117,1 generated by this
Since the adaptation of the nose 18 to the external skin layer is tight, the sensor becomes part of the skin B in operation. There is no struggle for the tube to enter the breathing holes in the patient's nose because the nosepiece sensor is entirely external.

7 and 8, the optical sensor 119 includes a ceramic substrate 130, electrical connections,
and a transparent sealing material 132 fixed to a ceramic substrate 130 by adhesive and by means of a microcircuit. The light emitting diode 120 consists of a ceramic substrate 133, electrical connections, and a transparent encapsulant 134 fixed to the ceramic substrate 133 by adhesive and by means of microcircuits. As for the dimensions, each ceramic substrate 133 is 4mm x 6mm.
mm, but other similar geometries may also be useful.

Light emitting diode 120 and photoelectric sensor 119
are a board arm 117 with an opening 125,
It is installed in 118. FIG. 6A shows a side view of the light emitting diode 120 and the photoelectric sensor 119. It will be appreciated that the device of the invention conforms flatly to the nasal surface despite the wide variety of nasal configurations common to humans.

The sensor is used as follows. That is, the user attaches one of the two board arms 117, 118 to one side of the human's nose, and then holds the second board arm to the other side of the human's nose (sixth
(See Figure A and Figure 6B). The base of the flexible substrate 116 is placed firmly against the bridge of the nose.

The base arms 117, 118 conform snugly to the skin layers of the nose. This tight compliance allows blood flow through the diaphragm without occlusion.

When the base and arms are in place, the light emitting diode 120 directs light into the vicinity of the nasal septum. The photoelectric sensor receives the light after the light passes through the nasal septum.

Various changes and modifications may be made to this embodiment without departing from what is considered the invention.

[Brief explanation of drawings]

Figures 1A and 1B show a common loop and hook type tape attachment system using a light source and optical sensor with some mass which creates the drawbacks described herein as artifacts, i.e. 1 is a perspective view of a prior art product illustrating a product of VELCRO. Figures 1C and 1D are diagrams of a clamp-on sensor attachment across a patient's finger. FIG. 1E is a diagram showing light absorption in the presence of artificial motion. FIG. 2A is a perspective view of the sensor of the present invention looking toward the optical sensor, light emitting die board, and adhesive surface. FIG. 2B is a diagram of the sensor of FIG. 2A showing the various layers of the present invention peeled away to expose the internal structure disclosed herein. FIG. 2C is an exploded side view of the sensor in which each of the composite elements of the selected embodiment of the substrate is individually illustrated and identified. FIG. 3A is a perspective view of the optical sensor and light source used in the invention disclosed herein. FIG. 3B is an enlarged view of a portion of FIG. 3A of a substrate with light emitting diodes. FIG. 3C is an enlarged view of the remaining portion of FIG. 3A of the substrate for supporting the photosensitive surface. FIG. 4 is a bottom view of a finger with the skin interrogation device of the present invention in place. FIGS. 5A and 5B are a plan view and a perspective view of a nose-piece type sensor attached to a person. Figures 6A and 6B are side and isometric views of a patient with the disclosed device in anatomical position. FIG. 7 is a perspective view of the nosepiece sensor showing the light emitting diode and light sensor assembly fixture, with an enlarged cross-sectional view of the light emitting diode and light sensor. FIG. 8 is an exploded view showing the flexible substrate, foam, electrical components, and other layers designed to monitor blood flow across the nasal septum. In these drawings, 10 is a sensor device;
14 and 24 are substrates, 25 and 26 are light emitting diodes (light sources), 27 is a substrate, 17 is a substrate, 19 is a photosensitive surface (light sensor), 30 is an opaque vinyl strip, 34 is a porous flexible tape layer, 35 37 is an adhesive surface, 37 is a strip, 38 is an adhesive layer, 40 and 41 are openings, 45 is a transparent polyester layer, 46 and 47 are adhesive coatings, and 50
Peel off tape layer, 116 is substrate, 117, 11
8 is a board arm, 119 and 120 are photoelectric components, 14
2 is an opaque photographic coating, 148 is a foam layer, 140
125 represents an adhesive layer, and 125 represents an opening.

Claims (1)

[Scope of Claims] 1. A non-invasive photoelectric sensor probe that is removably adhesively attached to a convex portion of a patient's skin and used to measure light absorption during transillumination of blood-perfused tissue beneath the skin. An apparatus comprising: a flexible, initially substantially planar, web-like support structure having substantially parallel spaced and opposing upper and lower surfaces; a light source attached to the web of the support structure; a light emitting surface oriented in the same direction as the lower surface), a light sensor attached to a web of the support structure, the light sensor having a light sensitive surface oriented in the same direction as the lower surface; is spaced from the light source in the plane of the support structure), as well as an adhesive layer on the outside of the lower surface, which removably adhesively secures the lower surface to the protrusion of the skin, thereby The surface is held conformable to the skin, and the support structure is flexible and conforms to the skin without stressing the skin and underlying tissue at any time during operation of the sensor probe, and the support structure is the condition of the convexity of the skin portion between the position and the light sensor such that the light emitting and light sensitive surfaces are tilted relative to each other such that light from the light source shines through the tissue between the light source and the light sensor; wherein the photosensitive surface receives at least a portion of the light. 2. the support structure incorporates: a relatively opaque bottom layer (except at the location of the light source and light sensor, where the bottom layer is relatively transparent), a top layer, and the light source and light sensor; 2. The apparatus of claim 1, further comprising means for adhesively securing said upper and lower layers.