DK201800042Y3 - Optical sensor for human pulse waveform - Google Patents

Abstract

The invention relates to the field of medicine and, in particular, to the functional diagnosis of a human condition, and may be used in medical studies, including for hemodynamics studies, and also for systems of fatigue monitoring of individuals driving vehicles. An optical sensor for human pulse waveforms includes an emitter module and a photoconductor module arranged in kinematically connected housings, and further includes a means for positioning the photoconductor module with respect to the emitter module using an elastic element simultaneously connected to the emitter module and photomodel module. and enabling displacement of the photoreceptor module relative to the emitter, the positions thereof being secured by abutting the skin surface of a person; the outer shape of the surface of an emitter holder is brought into contact with the inner surface of a lower portion of a person's outer ear, the emitter holder being made of an opaque, elastic material, and a positioning means including a linear guide whose axis is parallel to an optical axis linking the emitter and photo receiver.

Description

09) DENMARK (10)

⁽¹²⁾ USE MODEL WRITING

Registered utility model without testing

Patent and

Trademark Office (51) Int.CI .: A61B 5/1455 (2006.01) (21) Application number: BA 2018 00042 (22) Filing date: 2018-05-16 (24) Running day: 2016-11-15 (41) Aim. available: 2018-05-16 (44) The registration bkg. and published on: 2018-09-18 (86) International application no .: PCT / RU2016 / 000780 (86) International filing date: 2016-11-15 (30) Priority:

2015-11-27 RU 2015151141 (73) Model owner:

Konstantin Boleslavovich Tuminas, ul. Kirochnaya, d. 64, kv. 101 191015 Saint Petersburg, Russia (72) Produces:

Konstantin Boleslavovich Tuminas, ul. Kirochnaya, d. 64, kv. 101 191015 St. Petersburg, Russia (74) Plenipotentiary:

OTELLO ADVOKATANPARTSSELSKAB, Dalgasgade 25.8., 7400 Herning, Denmark (54) Title: Optical sensor for human pulse waveform (57) Summary:

The invention relates to the field of medicine and, in particular, to the functional diagnosis of a human condition, and may be used in medical studies, including for hemodynamics studies, and also for systems of fatigue monitoring of individuals driving vehicles. An optical sensor for human pulse waveforms includes an emitter module and a photoconductor module arranged in kinematically connected housings, and further includes a means for positioning the photoconductor module with respect to the emitter module using an elastic member simultaneously connected to the emitter module. and the photoreceptor module, which enables displacement of the photoreceptor module relative to the emitter, the positions thereof being secured by abutting the skin surface of a person; the outer shape of the surface of an emitter holder is brought into contact with the inner surface of the lower part of a person's outer ear, the emitter holder being made of opaque, elastic material, and a positioning means including a linear guide whose axis is parallel to an optical axis linking the emitter and photo receiver.

To be continued...

FIG. 1

Optical sensor for human pulse waveform

The area of production

The invention relates to the field of medicine and, in particular, to the functional diagnosis of a human condition, and it can be used for conducting medical examinations, including for examining hemodynamics, and also for systems for monitoring the fatigue of individuals driving vehicles.

Background to the creation

The pulse waveform, which occurs due to blood passing through human arteries, carries information regarding the state of this human circulatory system. Such information is important in predicting the effect of adverse environmental factors on the adaptability of the human body. One of the most widespread methods of recording the pulse waveform is sphygmography. This method utilizes sensors placed on a person's skin in areas directly above arteries. The pulse waveform is recorded using mechanical or optical methods based on sensor movement caused by an increase in arterial volume under the skin.

A pressure sensor (RU 2430344, G01L9 / 08, published on September 27, 2011, Bulletin 27) is known in that the sensor comprises a housing, a circular metal membrane, a disc-shaped quartz piezoelectric cell mounted on the surface of the crystal holder parallel to the membrane. with a gap between the cell and the membrane, where the center points of the disc-shaped piezoelectric cell and for the membrane are aligned with the longitudinal axis of the crystal holder, and a circular electrode disposed on the surface of the piezoelectric cell in a central portion thereof, a metal base comprising a bottom portion, an inner projection and an inner groove, a metal support ring having an outer diameter corresponding to the outer diameter of the membrane, a rivet with a flat cylindrical head, an elastic flat element with a central opening as the rivet passes therethrough, and a spherical end adjusting screw, the adjusting screw being screwed into a threaded hole in the center of the base of the metal base, coaxially therewith; o g such that the spherical end thereof contacts the flat surface of the rivet head, thereby creating a firm connection between the crystal holder and the elastic member wedge-fixed along the perimeter between the inner projection of the base and the inner surface of the support ring, the lower surface of the the support ring supports the metal membrane, wherein the outer cylindrical surface of the support ring is coupled in a continuous alignment with the surface of the inner groove in the base, the surface being limited in its depth at the bottom portion thereof by the inner projection and the upper and lower surfaces. of the support ring and base projection surface are parallel to the crystal holder surface, where the disc-shaped quartz piezoelectric cell is flat and where the circular electrode is arranged on the surface of the piezoelectric cell opposite the membrane. The sensor further comprises a first pneumatic duct which is formed a pneumatic filter and a reactor choke which interacts with each other and which is respectively formed a vertical cylindrical duct in the side wall of the base and which is filled with a filter material such as felt and a reactor shock formed by a horizontal, small diameter cylindrical channel, another pneumatic channel formed by a vertical cylindrical channel in the side wall of the base, a portion of this channel being filled with a filter material, and a horizontal, cylindrical channel with a spring loaded compensation valve formed by a cylinder having an annular groove along its surface and a pressure cap, the channels intercommunicating with each other, where the input of the pneumatic filter and the input of the second pneumatic channel are connected the inlet opening of the housing, the reactor choke output and the output of the second pneumatic duct being connected to each other by a volume defining of the wall, the bottom portion of the base and the inner membrane surface, and where this volume is connected to the inlet opening of the housing via the second pneumatic duct by means of the compensation valve when the sensor returns to its initial position. The piezoelectric sensor is used for sphygmographic studies using an occlusion band arranged on the forearm.

In addition to contact sensors, contactless pulse waveform sensors are also known. A publication (DA Usanov, AV Skripal, EO Kaschavtsev, Determining Pulse Waveform Based on a Semiconductor Laser Autodyne Signal, Letters to Technical Physics Journal, 2013, vol. 39, B. 5, pp. 82-87) describes a sensor, which is constituted by a semiconductor laser autodin comprising a quantum-sized laser diode InGaAIP structures in a diffraction limited single-spacer mode and beam wavelength of 654 nm, a stabilized electric power source for operation of the laser, and a photodetector for measuring the generated power output of the laser. When the sensor described above is used for sphygmographic studies, the laser should be directed to the skin surface of the wrist region, where the radial artery vein occurs closer to the skin surface. A portion of the radiation reflected from the skin surface returns to the laser resonator, generating laser power as the pulse waveform passes along the pulse vein, thereby changing. The change in laser power generation is detected using the photodetector and the output signal thereof is sent to a data processing and storage system.

The disadvantages of the prior art devices mentioned above are structural complexity and unsuitability for body-worn use in prolonged monitoring sessions of the circulatory system, especially with regard to the monitoring of a person handling vehicles.

A variety of sensors for monitoring the physiological parameters of the human circulatory system, including measuring oxygen concentrations in the blood, are well known; such sensors are structurally simple and can be worn. Such sensors are described e.g. the following patents: US 7263396, A61B 5/00, published Aug. 28, 2007; US 8532729, A61B 5/1455, published 10.09.2013; US 8588880, A61B 5/1455, published Nov. 19, 2013. Structurally, such sensors are ear clips that are adapted to mechanical attachment to a human body in the ear area, preferably on the earlobe. Such sensors include radiation sources and photo receivers, thereby enabling measurement of optical permeability for biological tissues rich in blood vessels and for recording oxygen concentration in blood.

The known solution, which forms the basis of the present invention, is a body-worn physiological sensor (US 8229532, A61B 5/1455, published 24/07/2012) including an emitter module and a photoconductor module arranged in kinematically connected housings where an output the sensor receiver module is an output of the sensor, the sensor further including a means for positioning the sensor receiver module relative to the emitter module, the means comprising an elastic member which is connected to both the emitter module and the sensor receiver module and which enables the sensor receiver module to be displaced relative to the emitter module. , while the positions thereof are secured by abutting the skin surface in the area of the outer ear of a person.

The main disadvantages of the known solution are low accuracy in recording the pulse waveform.

Despite the notion of structural simplicity, body arch sensors are complete devices that can perform even the most complex diagnostic tasks. The patient's health (and in some cases his / her own life) depends on the accuracy of such sensor readings. Details of utilization of various devices for conducting a non-invasive diagnostic method to evaluate the percentage oxyhemoglobin in blood are discussed in detail in the publication of D.A. Rogatkin, Physical basics of optical oxymetry, Medical physics, 2012, issue 2, pp. 97-114. The technical requirements for the development and production of optical oximeters are described in the publication regarding international standards ISO 9919: 2011, Medical electrical equipment - Particular requirements for the basic safety and essential performance of pulse oximeter equipment for medical use.

Led by the high demands placed on accuracy for sphygnometric and oxymetric measurements obtained with body-borne optical pulse waveform sensors, the security of attachment thereof to the body of persons monitored over extended periods of time while carrying the device in a wide spectrum of climatic conditions and under outdoor lighting conditions with minimal nuisance, a number of mandatory requirements can be summarized as follows:

• Sensor structure should enable attachment thereof to a human body part which does not tend to accidental contact with clothing and which also provides the highest concentration of capillary blood vessels;

• Sensor attachment to the body must be as safe as possible, without unintended movement due to human movement, while avoiding even the slightest nuisance due to disturbance or obstruction of peripheral blood circulation in the attachment area. Sensor weight should be minimal;

• Sensor structure should exclude or minimize the effect of the photographer's exposure to external light sources to the highest possible degree, while providing the greatest possible signal-to-noise ratio;

• The means for securing the sensor to the human body must provide the emitter and receiver positions for individual physiological characteristics of the subject being examined, without changing the calibration parameters of the device or the method of data analysis of the data being received.

Summary of the production

The object of the invention is to provide increased accuracy in recording pulse waveform and measurement of human hemodynamic parameters by obtaining, as a technical effect, increased signal-to-noise ratio.

The described technical effect is achieved with an optical sensor for human pulse waveforms, wherein the optical sensor includes an emitter module and a photoconductor module arranged in kinematically connected housings, an output of the photoconductor module being an ouput from the sensor, the optical sensor further including an means for positioning the receiver module relative to the emitter module, the means comprising an elastic member which is connected both to the emitter module and to the sensor receiver module, and which allows the displacement of the sensor receiver module relative to the emitter module, while ensuring its positions by abutting the skin surface. person; wherein an outer shape of the surface of an emitter holder is configured to abut an inner surface of a lower portion of the outer ear and the intertragal notch of the person, wherein the emitter holder is made of an opaque, elastic material and the positioning means includes a linear guide with an axis extending parallel to an optical axis linking the emitter and the receiver, while ensuring a coaxial position for the emitter and the receiver.

In addition, the optical sensor emitter may comprise two radiation sources with beam wavelengths λΐ and λ2 selected in the spectral ranges λΐ = 640-720 nm and λ2 = 960-1040 nm.

Pulse waveform (sphygmogram) analysis in humans provides evidence of the general physiological state of a person, as well as of the state of their circulatory system in particular, ie. blood flow to and from capillaries, vascular tone and elasticity, volumetric obstruction of blood vessels, wall elasticity of large blood vessels, myocardial contractile function, etc. Examination of a pulse waveform using optical light transmittance sensors includes measurement of attenuation of radiation by blood filled tissue in different spectra.

This process includes simultaneous recording of changes in vascular volume during the pulse wave (sphygmogram waveform) and oxyhemoglobin concentration in blood (differential transmission at different wavelengths). It should be noted that hemodynamics are determined solely from the sphygmogram waveform, whereas blood oxygenation affects the waveform amplitude, assuming that the oxygen content of the blood remains generally constant over the course of a single pulse wave period. The accuracy of measured hemodynamic characteristics in particular, and of sensor performance in general, depends on the degree of fulfillment of the essential requirements for sensor structure and attachment to a person's body.

The structure of the described embodiment comprises a new technical solution (claimed features), with the combination thereof obtaining the claimed technical effect, these features comprising the following:

1) An outer shape of a surface of an emitter holder is configured to abut an inner surface of a lower portion of a person's outer ear in the region defined by the tragus and antitragus. This allows for secure attachment to the person's body in an area which does not tend to come into direct contact with clothing, but which includes sufficiently close capillary mesh. Contrary to known sensors adapted to the ear lobe fuse, the structure of the present invention provides attachment to a cartilaginous portion of the outer ear, thereby eliminating possible nuisance (numbness) caused by prolonged wear of the sensor and providing a further higher level and quality of the output signal from the sensor due to greater blood vessel density and diameter of the outer ear tissue in the sensor location area. Further, the center of gravity of the sensor is located between the optical axis of the sensor and the positioning guide. This arrangement allows for the minimization of torque and its effect on the sensor output signal during wear (minimizing noise levels due to natural head movements) while maintaining aesthetic, visual appeal for the sensor being worn, which is especially important for women.

2) To prevent exposure from the surroundings of the sensor-receiver, caused by radiation from external sources, the emitter is provided with an opaque holder so that an outer surface of the emitter abuts the inner surface of the lower part of the person's outer ear and follows the contour of the outer surface of the antitragus. The holder provides a decrease in the photocopier

Ί Exposure levels under changing lighting conditions and reduce pressure on the surface of the outer ear and provide a more comfortable longer-lasting wear.

3) The sensor structure provides an individual-specific adjustment with respect to relative positioning of the emitter and receiver modules while maintaining its orientation using a linear guide.

Brief description of the figures

The production is described with reference to the attached figure.

FIG. 1 is a general view of the sensor described,

FIG. 2 is a sectional view of the sensor structure,

FIG. 3 is a schematic illustration of a human ear showing the attachment position of the sensor,

FIG. 4 illustrates results of a comparison test between the described sensor and a prior art sensor, the results confirming the validity of the claimed technical effect.

FIG. 2 includes the following reference numbers: emitter 1; emitter holder 2; emitter module housing 3; photo receiver 4; photo receiver housing 5; linear guide 6; and springs 7.

FIG. 3 includes the following reference numbers: tragus 8; antitragus 9; intertragal notch 10 (shadow area corresponding to the region where the emitter holder 2 of the described sensor abuts against the ear); and earlobe 11.

The sensor described comprises an emitter 1 mounted within a holder 2 and arranged within an emitter module housing 3, and a photo receiver 4 mounted within a holder and arranged within a photo receiver module housing 5. The emitter 1 comprises: for example, a red LED and an infrared LED, which emit radiation within spectral ranges of respectively. 640 720 nm and 960 -1040 nm, it being known that the extinction coefficients of oxyhemoglobin and deoxyhemoglobin are most markedly different in the above ranges. Houses 3 and 5 for respectively. the emitter module and the photo receiver module 4 are made of a light, durable plastic material, e.g. polycarbonate. The structure of the described sensor enables linear displacement of the emitter module housing 3 with respect to the photoconductor module housing 5 along a linear guide 6, the axis thereof being parallel to the optical axis of the device and connecting the emitter 1 and the sensor element of the photoconductor 4. Linear springs 7 which is symmetrically mounted on both sides of the linear guide 6 providing attractiveness ", wherein the emitter 1 is directed toward the photoconductor 4 in any position due to the action of the linear guide 6. The holder 2 of the emitter 1 is made of a resilient, opaque material. eg. carbonized silicone. This embodiment of the holder prevents exposure from the surroundings of the photo receiver 4.

FIG. Figure 4 shows two graphs illustrating waveforms for a patient under study, where data is received from two sensors with identical optical / electronic structure but with different constructs. A lower graph shows the pulse graph form received from the output of the known sensor, whereas an upper graph shows the waveform received with the invoked sensor. An enlarged image shows additional areas of both graphs at local maximum values. Analysis of the pulse waveforms shows that the signal-to-noise ratio of the present generation exceeds the same for the known sensor by about 30 db. This increased quality provides an increase in the detection accuracy of human hemodynamics. The magnification area (Image A) clearly shows pulse waveform characteristics of a local maximum range, whereas such characteristics of the waveform measured by prior art (Image B) are completely masked by noise

Thus, the described human sensor pulse waveform optical sensor comprises a combination of features whereby the technical power with increased measured accuracy is obtained due to an increase in signal-to-noise ratio value.

Claims (2)

Use Model Requirements An optical sensor for human pulse waveforms, wherein the optical sensor includes an emitter module and a sensor receiver module arranged in kinematically connected housings, wherein an output of the sensor receiver module is an output of the sensor, the optical sensor further including a means for positioning the sensor module. relative to the emitter module, the means comprising an elastic member which is connected to both the emitter module and the photodetector module, and which allows the photodetector module to be displaced relative to the emitter module, while the positions thereof are secured by contacting the skin surface of a person; new in that an outer shape of the surface of an emitter holder is configured to abut an inner surface of a lower part of the person's outer ear, wherein the emitter holder is made of an opaque, elastic material and the positioning means includes a linear guide with an axis extending parallel to an optical axis linking the emitter and the receiver, thereby ensuring a coaxial position for the emitter and the receiver. Human pulse waveform optical sensor according to claim 1, characterized in that the emitter comprises two radiation sources and that radiation wavelengths λ1 and λ2 are selected in the spectral ranges λ1 = 640-720 nm and λ2 = 960-1040 nm. 1.4