SE545864C2 - An optical sensor plate for measuring blood flow via the skin of a patient - Google Patents
An optical sensor plate for measuring blood flow via the skin of a patient Download PDFInfo
- Publication number
- SE545864C2 SE545864C2 SE2051096A SE2051096A SE545864C2 SE 545864 C2 SE545864 C2 SE 545864C2 SE 2051096 A SE2051096 A SE 2051096A SE 2051096 A SE2051096 A SE 2051096A SE 545864 C2 SE545864 C2 SE 545864C2
- Authority
- SE
- Sweden
- Prior art keywords
- optical
- flexible support
- major surface
- optical source
- cover
- Prior art date
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 192
- 230000017531 blood circulation Effects 0.000 title claims abstract description 18
- 238000005266 casting Methods 0.000 claims description 44
- 239000000463 material Substances 0.000 claims description 43
- 238000000034 method Methods 0.000 claims description 15
- 239000011247 coating layer Substances 0.000 claims description 14
- 239000004033 plastic Substances 0.000 claims description 10
- 229920003023 plastic Polymers 0.000 claims description 10
- 230000005540 biological transmission Effects 0.000 claims description 8
- 229920001296 polysiloxane Polymers 0.000 claims description 8
- 239000010410 layer Substances 0.000 claims description 7
- 239000007788 liquid Substances 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 4
- 229920001971 elastomer Polymers 0.000 claims description 3
- 238000004026 adhesive bonding Methods 0.000 claims description 2
- 208000004210 Pressure Ulcer Diseases 0.000 description 9
- 238000013186 photoplethysmography Methods 0.000 description 7
- 239000004593 Epoxy Substances 0.000 description 6
- 238000005259 measurement Methods 0.000 description 6
- 229920002635 polyurethane Polymers 0.000 description 5
- 239000004814 polyurethane Substances 0.000 description 5
- 206010011985 Decubitus ulcer Diseases 0.000 description 4
- 238000009825 accumulation Methods 0.000 description 3
- 230000001580 bacterial effect Effects 0.000 description 3
- 238000012502 risk assessment Methods 0.000 description 3
- 208000027418 Wounds and injury Diseases 0.000 description 2
- 230000006378 damage Effects 0.000 description 2
- 208000014674 injury Diseases 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- 239000004952 Polyamide Substances 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000037396 body weight Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000003618 dip coating Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 235000015097 nutrients Nutrition 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000009832 plasma treatment Methods 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 230000009885 systemic effect Effects 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/44—Detecting, measuring or recording for evaluating the integumentary system, e.g. skin, hair or nails
- A61B5/441—Skin evaluation, e.g. for skin disorder diagnosis
- A61B5/447—Skin evaluation, e.g. for skin disorder diagnosis specially adapted for aiding the prevention of ulcer or pressure sore development, i.e. before the ulcer or sore has developed
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
- A61B5/026—Measuring blood flow
- A61B5/0261—Measuring blood flow using optical means, e.g. infrared light
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
- A61B5/026—Measuring blood flow
- A61B5/0295—Measuring blood flow using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/145—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue
- A61B5/1455—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue using optical sensors, e.g. spectral photometrical oximeters
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
- A61B5/7271—Specific aspects of physiological measurement analysis
- A61B5/7275—Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
- A61B2562/02—Details of sensors specially adapted for in-vivo measurements
- A61B2562/0233—Special features of optical sensors or probes classified in A61B5/00
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
- A61B2562/04—Arrangements of multiple sensors of the same type
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
- A61B2562/12—Manufacturing methods specially adapted for producing sensors for in-vivo measurements
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
- A61B2562/16—Details of sensor housings or probes; Details of structural supports for sensors
- A61B2562/164—Details of sensor housings or probes; Details of structural supports for sensors the sensor is mounted in or on a conformable substrate or carrier
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/0059—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence
- A61B5/0062—Arrangements for scanning
- A61B5/0064—Body surface scanning
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/44—Detecting, measuring or recording for evaluating the integumentary system, e.g. skin, hair or nails
- A61B5/441—Skin evaluation, e.g. for skin disorder diagnosis
- A61B5/445—Evaluating skin irritation or skin trauma, e.g. rash, eczema, wound, bed sore
Abstract
An optical sensor plate (1) for measuring blood flow, comprising: a flexible support (2) having a first (2a) and a second major surface (2b), an optical source (3) and an optical detector (4) arranged on the first major surface (2a). The optical source (3) emitting light into the skin of a subject and the detector (4) detecting light after reflection in the skin and underlying tissue. The optical source (3) and the optical detector (4) being separated on the first major surface (2a) by an optically opaque wall (5), such that the amount of light reaching the optical detector (4) directly from the optical source (3) is limited. A cover (6) is arranged on the first major surface (2a) of the flexible support (2), covering and embedding the optical detector (4), the optical source (3) and the opaque wall (5).
Description
1 AN OPTICAL SENSOR PLATE FOR l\/IEASURING BLOOD FLOW XfåA THE SKEN OF A PATIENT
TECHNICAL FIELD [001] The present document relates to an optical sensor plate and to a method of
producing such an optical sensor plate.
BACKGROUND ART [002] Pressure ulcers afflict people of all ages across the globe and are one of the most common injuries suffered by patients in the course of care. A pressure ulcer is an injury to the skin and/or underlying tissue caused by insufficient blood flow as a result of pressure on the skin, for example, due to extended periods of laying or sitting. The pressure deprives the cells of the oxygen and nutrients they need. Pressure ulcers are the cause of tremendous suffering, high healthcare costs and can occasionally lead to death.
[003] Patients undergo a pressure ulcer risk assessment when admitted to hospitals and care homes according to established methods; usually through the application of assessment scales. Those patients who are assessed to have the greatest risk of developing pressure ulcers are the most likely to be treated using preventative measures. Assessment scales are widely used, but these are not very precise since they rely on an assessment of the patient's condition and are rather subjective. ln WO2019/190378 is described a method and technique based on an assessment of the individual's physiological status, through an examination of the patient's superficial blood flow in places where pressure ulcers tend to occur, and the skin is bearing the patient's body weight. Blood flow data related to the assessed area while subjecting the assessed area to the at least two different pressure states is obtained by means of photoplethysmography and the risk of pressure ulcers on the patient is based on assessment ofthe blood flow data obtained for the at least two different pressure states. [004] ln photoplethysmography (PPG) the skin is illuminated and the reflected light is
measured by applying a sensor unit to a skin surface. This is an established technology that is
used in for example heart rate monitors and other devices.
2 [005] A PPG sensor for use in pressure ulcer risk assessment, as well as other optical sensors used for measuring blood flow in superficial tissue, need to be flexible such as to follow the shape ofthe body ofthe patient and also be biocompatible as it is applied in contact with the skin surface of the patient. [006] ln for example WO2014/165022, is shown a flexible optical sensor comprising a flexible support pad onto which optical light sources and light detectors are mounted. The support pad being arranged to be in contact with a skin surface of a patient allowing light from the light source to be reflected in the superficial tissue and thereafter detected by the
detector.
SUMMARY OF THE INVENTION [007] lt is an object of the present disclosure to provide an improved or at least an alternative flexible optical sensor plate to what is known in prior art and a method of producing such a optical sensor plate.
[008] The invention is defined by the appended independent patent claims. Non- limiting embodiments emerge from the dependent patent claims, the appended drawings and the following description.
[009] According to a first aspect there is provided an optical sensor plate for measuring blood flow of a subject. The optical sensor plate comprises a flexible support having a first major surface and an opposing second major surface, at least one optical source arranged on the first major surface ofthe flexible support, and arranged to emit light, and at least one optical detector arranged on the first major surface of the flexible support, and arranged to detect light from said optical source. The flexible support is configured to conform to a skin surface of a subject such that the at least one optical source emits light into the skin and underlying tissue and the at least one optical detector detects light from the at least one optical source after reflection in the skin and underlying tissue. The at least one optical source and the at least one optical detector are separated on the first major surface of the flexible support by (a) wall(s) being optically opaque to wavelengths implemented by the at least one optical source and the at least one optical detector, such that the amount of light reaching the
optical detector directly from the optical source is limited. A biocompatible, transparent and
elastic cover is arranged on the first major surface of the flexible support, covering andembedding the at least one optical detector, the at least one optical source and the opaque wall(s) arranged on the flexible support.
[0010] The optical sensor plate may for example be used in photoplethysmography or in other optical sensors used for measuring blood flow in the skin and underlying tissue of a patient. [0011] As the at least one optical source and the at least one optical detector are separated on the first major surface ofthe flexible substrate by optically opaque walls, no or very little light reaches the optical detector directly from the at least one optical source through cross-talk, and light detected by the detector is mainly light reflected in the skin and underlying tissue.
[0012] The cover is arranged on the first major surface of the support, covering and embedding the at least one optical detector, the at least one optical source and the opaque wall(s) arranged on the support. When measuring a blood flow of a patient, the cover is arranged in contact with the skin of the patient. The cover, hence, protects the optical elements on the major surface of the support during measurements.
[0013] By embedding is here meant that not only does the cover lie on top ofthe optical elements and opaque wall(s) arranged on the support. The cover is also arranged to fill in all cavities between optical elements and opaque walls arranged on the first major surface ofthe flexible support.
[0014] With such an optical sensor plate, the first major surface thereof, provided with the cover and arranged to be in contact with the skin of a patient during measurements, exhibits a smooth, biocompatible surface, without cavities, cracks orjoints, thereby preventing bacterial accumulation at the first major surface. Further, the cover also makes the optical sensor plate possible to clean.
[0015] As the optical components and wall(s) are embedded in the cover, there are no or at least very small air pockets created in the vicinity of the optical components. Thereby, light emitted from the optical source, reflected in the skin or underlying tissue and detected by the optical detector travels through the transparent cover without phase transitions created by air pockets in the vicinity of the optical components.
[0016] The opaque wall(s) may be made of a plastic material, silicone or rubber.
[0017] The plastic material may for example be polyurethane or epoxy.
4 [0018] The biocompatible, transparent and elastic cover may be made of a plastic
material or silicone.
[0019] The plastic material may for example be polyurethane or epoxy. [0020] The cover may have a level of transmission of at least 85%. [0021] With a lower level of transmission, the quality of the blood flow measurements
may deteriorate. Using a cover with a lower transmission level is possible, such as a
transmission level of 70% or more, if the brightness of the optical source is adjusted.
[0022] A thickness of the cover covering the optically opaque wall(s) may be less than 0.6 mm. [0023] The thickness of the cover covering the wall(s) may be less than about 0.6 mm
but preferably not less than about 0.1 mm. The thinner the thickness of the cover covering the wall(s), the less problems with light reaching the optical detector directly from the at least one optical source through cross-talk over the wall(s), and light detected by the detector is mainly light reflected in the skin and underlying tissue.
[0024] The thickness of the cover covering the optical elements may be similar to the thickness of the cover covering the wall(s) or be slightly thicker as the walls may protrude from
the major surface a bit longer than the optical elements protrude from the major surface. The
thickness of the cover covering the optical elements may be about 0.1 mm to about 1 mm.
[0025] A coating layer may be arranged on the cover having a thickness of 0.5 mm or less. [0026] According to a second aspect there is provided a method of producing an optical
sensor plate for measuring blood flow of a subject. The method comprises to provide a flexible support having a first major surface and an opposing second major surface, arrange at least one optical source on the first major surface ofthe flexible support, the optical source being arranged to emit light, and arrange at least one optical detector on the first major surface of the flexible support, wherein the at least one optical detector is arranged to detect light from said optical source. The flexible support is configured to conform to a skin surface of a subject such that the at least one optical source emits light into the skin and underlying tissue and the at least one optical detector detects light from the at least one optical source after reflection in the skin and underlying tissue. The at least one optical source and the at least one optical detector are separated on the first major surface ofthe flexible support by walls being
optically opaque to wavelengths implemented by the at least one optical source and the at
least one optical detector such that the amount of light reaching the optical detector directly from the optical source is limited, and a biocompatible, transparent and elastic cover casted on the first major surface ofthe flexible support, covering and embedding the optical
detector, optical source and opaque wall(s) arranged on the flexible support.
[0027] The optically opaque wall(s) may be arranged on the first major surface by gluing.
[0028] Prior to casting, the optically opaque wall(s) may be treated with plasma and/or primer.
[0029] The casting step may comprise to provide a casting tool comprising a first part
arranged to receive the first major surface of the flexible support and a second part arranged to form a lid over the first part, cover the insides of at least the first part of the casting tool with a layer of liquid covering material, heating the casting tool with covering material until the covering material is partially cured, arranging the flexible support with the at least one optical source, the at least one optical detector and the optically opaque wall(s) arranged thereon on the partially cured covering material in the first part of the casting tool, arranging the second part ofthe casting tool on the first part covering the flexible support, adding liquid covering material to the casting tool, heating the casting tool until the covering material is fully cured, and removing the thus formed covered optical sensor plate from the casting tool.
[0030] The method may further comprise applying a coating layer on the cover.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Fig. 1 is a cross sectional side view of an optical sensor plate comprising a flexible support with an optical source and an optical detector arranged on a major surface thereof. The optical elements being separated by an optically opaque wall. A cover is arranged on the first major surface ofthe flexible support, covering and embedding the optical detector, the optical source and the opaque wall.
[0032] Fig. 2 shows a top view of a flexible support with an optical source and an optical detector arranged on a major surface thereof.
[0033] Fig. 3 is a side view of the flexible support shown in Fig. 2. [0034] Fig. 4 shows a sheet of optically opaque material with cut-outs for optical
elements.
6 [0035] Figs 5a and 5b show a casting tool for producing a cover on a flexible support with optical elements as shown in Figs 2 and 3. ln Fig. 5a a first part ofthe casting tool is shown arranged to receive the first major surface of the flexible support with the optical elements and opaque walls arranged thereon. ln Fig. 5b a second part ofthe casting tool is shown which is arranged to form a lid over the first part of the casting tool. [0036] Fig. 6 is a top view of the optical sensor plate shown in Fig. 1. [0037] Fig. 7 schematically illustrates a method of producing the optical sensor plate
shown in Figs 1 and
DETAILED DESCRIPTION [0038] A photoplethysmography sensor plate for use in pressure ulcer risk assessment, as well as other optical sensors plates used for measuring blood flow in superficial tissue, need to be flexible such as to follow the shape of the body of the patient allowing light from light sources to be reflected in the superficial tissue and thereafter detected by detectors. Such a sensor plate also needs to be biocompatible as it is applied in contact with the skin surface of the patient. [0039] ln Fig. 1 is shown a cross sectional side view of an optical sensor plate 1 for use
in measuring blood flow of a subject for example in photoplethysmography. The optical sensor plate 1 comprises a flexible support 2 having a first major surface 2a and an opposing second major surface 2b. The flexible support 2 may be a substantially flat shaped, flexible support. ln one alternative embodiment, at least the first major surface 2a inay have a cohcave curvatißre in an unbiased state. in some esnbodintents, the flexâbie support 2 is configureci to flex in at Eeast one orthogonai direction. Aiteritativeiy, the fiexibie support :nav be configureci to flex in at Eeast tvvo orthogonal directions, such as the x and y-directions.
[0040] At least one optical source 3 is arranged on the first major surface 2a of the flexible support 2, and is arranged to emit light. The optical source may be a LED. At least one optical detector 4 is arranged on the first major surface 2a of the flexible support 2, and is arranged to detect light from the optical source 3. The optical detector may be a photodetector. ln some embodiments, the optical sensor plate 1 comprises at least two
optical sources 3, each optical source 3 emitting light of different wavelengths, such as red
and green light.
7 [0041] The optical source 3 and optical detector 4 are arranged on the first major surface 2a of the flexible support 2, protruding in a direction normal to the first major surface 2a. The flexible support 2 may he a prlhtefl Circuit board (PCB), see Figs 1-3, having a first rrlajor' surface Ba with cohcluctive traces thereon and the optical elements, i.e. optical source(s) and optical detectorlsl, arranged thereon and electrically couplecl to the eonductlve traces of the FEB, The flexible support 2 ihay be comprised of rlgld parts onto vvhlch the optical elements 3, 4 [and cohcluctlve tracesj are arranged tft/lth flexible parts cohnectlng the rlgid parts of the PCB. The rigid parts could for example he ofglass~reinforced epoxy lamlhate material such as FR-Ål. The flexible parts may for example be rnacle of polyamide, [0042] The flexible support 2 is configured to conform to a skin surface of a subject, such as an area of the back of a patient, such that the optical source(s) 3 emit(s) light into the skin and underlying tissue and the at least one optical detector 4 detects light from the at least one optical source 3 after reflection in the skin and underlying tissue. [0043] The at least one optical source 3 and optical detector 4 are separated on the first major surface 2a of the flexible substrate 2 by an optically opaque wall or walls 5. The wall 5 being optically opaque to wavelengths implemented by the at least one optical source 3 and the at least one optical detector 4, such that the amount of light reaching the optical detector 4 directly from the optical source 3 is limited, i.e no or little cross-talk, and light detected by the detector 4 is mainly light reflected in the skin and underlying tissue. The material of the optically opaque wall(s) 5 may be a plastic material, silicone, or rubber. The plastic material may for example be polyurethane or epoxy. [0044] The optically opaque wall(s) 5 arranged on the first major surface 2a ofthe flexible support, protrudes in a direction normal to the first major surface 2a. The optically opaque walls 5 may have the form of a sheet or liner with cut-outs, see Fig. 4, for optical elements and other components arranged on the first major surface of the flexible support 2. Alternatively, the walls 5 may be comprised of strips, squares or similar arranged on the first major surface. The optically opaque walls (5) may be glued on the first major surface 2a ofthe flexible support (2). [0045] ln Fig. 7 is schematically illustrated a method for producing the optical sensor plate 1 described above. Having provided 100 the flexible support 2, arranged thereon 101,
102 at least one optical source 3 and at least one optical detector 4, and separated 103 the at
least one optical source 3 and the at least one optical detector 4 with optically opaque walls 5,a biocompatible, transparent and elastic cover 6 is casted 104 on the first major surface 2a of the flexible support 2, covering and embedding the optical detector 4, optical source 3 and opaque wa||(s) 5 arranged on the flexible support 2. Prior to casting 104, the optically opaque wa||(s) 5 may be treated with plasma and/or primer
[0046] ln Fig. 6 is shown an optical sensor plate with such a cover 6. [0047] When measuring a blood flow of a patient using the optical sensor plate 1, the cover 6 is arranged in contact with the skin ofthe patient. The other parts arranged on the major surface are, hence, protected from direct contact with the skin surface.
[0048] A thickness of the cover 6 covering the optically opaque wa||(s) 5 may be less than 0.6 mm. The thinner the thickness of the cover 6 covering the wa||(s) 5, the less problems with light reaching the optical detector 4 directly from the at least one optical source 3 through cross-talk over the wa||(s) 5, and light detected by the detector 4 is mainly light reflected in the skin and underlying tissue. The thickness of the cover 6 covering the optical elements 3, 4 may be similar to the thickness of the cover covering the wa||(s) or be slightly thicker as the walls may protrude from the major surface a bit longer than the optical elements 3,
[0049] That the cover 6 is biocompatible is here meant that a two-way response, i.e., the body's response to the cover and the cover's response to the body. The biocompatibility refers to the ability of the cover to perform its intended function, without eliciting any significant or long-term undesirable local or systemic effects in the patient. The biocompatible cover should preferably be compatible in accordance with the ISO 10993 standard.
[0050] That the cover 6 is transparent is here meant that objects covered can be distinctly seen and that the cover is being transparent to wavelengths emitted by or detected by the optical elements, and may have a level of transmission of at least 85%.
[0051] The cover 6 may be made of a plastic material or silicone. The plastic material may for example be polyurethane or epoxy. The material may for example be a two- component silicone.
[0052] That the cover 6 is elastic is here meant that the cover conforms to the flexibility of the flexible support 2 without rupturing. The elastic cover should have an elastic elongation, i.e. the maximum length the cover can be stretched without breaking as a percentage of the
material's original length, such as at least 50%, or at least 75% or at least 100%.
9 [0053] The cover 6 is arranged on the first major surface 2a of the support 2, covering and embedding the at least one optical detector 3, the at least one optical source 4 and the opaque wa||(s) 5 arranged on the support 2. The cover 6, hence, protects the optical elements on the major surface of the support. The cover is arranged to cover at least a portion of the first major surface. The cover can also be arranged to cover the whole first major surface 2a and possibly also edges thereof. The cover 6 may also be arranged to cover the second major surface 2b of the flexible support 2. The optical sensor plate 1 may also comprise other electronic components, protected by the cover 6, such as a micro controller, lCs, AD converter, etc. [0054] By embedding is here meant that not only does the cover 6 lie on top ofthe optical elements 3, 4 and opaque wa||(s) 5 arranged on the support. The cover 6 is also arranged to fill in all cavities between optical elements 3, 4 and opaque walls 5 arranged on the first major surface 2a of the flexible support 2. [0055] With such an optical sensor plate 1, the first major surface 2a thereof, provided with the cover and arranged to be in contact with the skin of a patient during measurements, exhibits a smooth, biocompatible surface, without cavities, cracks orjoints, thereby preventing bacterial accumulation at the first major surface. Further, the cover 6 also makes the optical sensor plate 1 possible to clean. An outer surface of the cover may have a surface finish of at least Ra 3.2 pm. (Ra being the arithmetic average of a set of individual measurements of surface peaks and valleys.) [0056] As the optical components 3, 4 and wa||(s) 5 are embedded in the cover 6, there are no or at least very small air pockets created in the vicinity of the optical components. Thereby, light emitted from the optical source 3, reflected in the skin or underlying tissue and detected by the optical detector 4 travels through the transparent cover 6 without phase transitions created by air pockets in the vicinity of the optical components. [0057] ln Fig. 7 is further illustrated an embodiment ofthe casting step 104. A casting tool 10, see Figs 5a and 5b, is provided 104a and comprises a first part 10a arranged to receive the first major surface 2a of the flexible support 2 with optical elements 4, 5 and opaque wa||(s) 5 arranged thereon, and a second casting tool part 10b is arranged to form a lid over the first part 10a. The insides of the first part 10a of the casting tool 10 are covered 104b with
a layer of liquid covering material. Optionally also the insides of the second part 10b ofthe
casting tool 10 are covered 104b with a layer ofthe liquid covering material. The casting tool
with covering material is heated 104c until the covering material is partially cured. Thereafter, the flexible support 2 with the at least one optical source 3, the at least one optical detector 4 and the optically opaque wall(s) 5 arranged thereon is arranged 104d on the partially cured covering material in the first part 10a of the casting tool 10. The second part 10b of the casting tool 10 is arranged 104e on the first part 10a covering the second major surface 2b ofthe flexible support 2. Thereafter liquid covering material is added 104f to the casting tool 10, and the casting tool 10 heated 104g until the covering material is fully cured. Finally, the thus formed covered optical sensor plate 1 is removed 104h from the casting tool 10. lf also the second part 10b ofthe casting tool is 10 is covered with covering material the second major surface 2b of the support 2 will also be covered with cover 6. The casting tool may be made ofaluminium.
[0058] The curing may be done in an oven at temperatures up to 150°C. The curing temperature depends on the material used for the cover 6. With partially cured is here meant that the material is cured during only a part of its curing time, such that the material becomes hard but still sticky so it will adhere well to material that is added and such that when placing the flexible support 2 with the elements arranged thereon on the partially cured cover material, the flexible support will not sink to the bottom ofthe first part 10a of the casting tool 10 but stay on top of the half-cured material.
[0059] The thickness of the layer of casting material in the second part 2b of the casting tool may be in the order of 0.05-1.5 mm. Thereby, a thickness of the cover 6 on the second major surface 2b of the support 2 may be 0.05-1.5 mm.
[0060] Through the casting procedure, also edges of the support 2 connecting the first and second major surfaces 2a, 2b, may be covered with the cover 6 (see Fig. 1).
[0061] Prior to casting, the optically opaque walls may be treated with plasma and/or primer for activation of the material and better wettability. The plasma treatment could be for example low-pressure plasma or atmospheric pressure plasma. The primer could for example be applied by brush or spray.
[0062] A coating layer 7 may be applied 106 on the cover 6 (see Fig. 1) through for example flow coating, spray coating or dip coating. The coating layer may for example be of silicone, polyurethane or epoxy. The coating layer 7 may increase the strength and durability
of the cover layer 6 and, hence, ofthe optical sensor plate 1. The thickness ofthe coating layer
may be less than 0.5 mm and preferably less than 0.1 mm, such that the coating layer 7 doesnot affect the properties of the cover 6 and the optical sensor plate 1. The coating layer 7 may be arranged on the cover 6 on the first major surface 2a, and/or on the second major surface 2b and/or on edges of the support 2 connecting the first and second major surfaces 2a, 2b. [0063] The transmission requirements on the coating layer 7 are similar to the transmission requirements on the cover 6. The coating layer 7 could be a layer, which is somewhat harder than the cover 6. As the coating layer 7 is arranged to be in contact with the skin of a patient during measurements, it should exhibit a smooth, biocompatible surface, without cavities, cracks orjoints, thereby preventing bacterial accumulation. lt should further
be possible to clean. An outer surface of the coating layer 7 may have a surface finish of at
least Ra 3.2 pm.
Claims (11)
1. An optical sensor plate (1) for measuring blood flow of a subject, comprising: a flexible support (2) having a first major surface (2a) and an opposing second major surface (2b), at least one optical source (3) arranged on the first major surface (2a) of the flexible support (2), and arranged to emit light, at least one optical detector (4) arranged on the first major surface (2a) of the flexible support (2), and arranged to detect light from said optical source (3), the flexible support (2) being configured to conform to a skin surface of a subject such that the at least one optical source (3) emits light into the skin and underlying tissue and the at least one optical detector (4) detects light from the at least one optical source (3) after reflection in the skin and underlying tissue, the at least one optical source (3) and the at least one optical detector (4) being separated on the first major surface (2a) of the flexible support (2) by (a«}~wall(s) (5) being optically opaque to wavelengths implemented by the at least one optical source (3) and the at least one optical detector (4), such that the amount of light reaching the optical detector (4) directly from the optical source (3) is limited, a biocompatible, transparent and elastic cover (6) arranged on the first major surface (2a) of the flexible support (2), covering and embedding the at least one optical detector (4), the at least one optical source (3) and the opaque wall(s) (5) arranged on the flexible support (2).
2. The optical sensor plate (1) of claim 1, wherein the optically opaque wall(s) (5) is/are made of a plastic material, silicone or rubber.
3. The optical sensor plate (1) of claim 1 or 2, wherein the biocompatible, transparent and elastic cover (6) is made of a plastic material or silicone.
4. The optical sensor plate (1) of any of claims 1-3, wherein the cover (6) has a level of transmission of at least 85%.
5. The optical sensor plate (1) of any of claims 1-4, wherein a thickness of the cover (6) covering the optically opaque wa||(s) (5) is less than 0.6 mm.
6. The optical sensor plate (1) of any of claims 1-5, wherein a coating layer (7) is arranged on the cover (6) having a thickness of 0.5 mm or less.
7. A method of producing an optical sensor plate (1) for measuring blood flow of a subject, comprising: providing (100) a flexible support (2) having a first major surface (2a) and an opposing second major surface (2b), arranging (101) at least one optical source (3) on the first major surface (2a) of the flexible support (2), the optical source (3) being arranged to emit light, arranging (102) at least one optical detector (4) on the first major surface (2a) of the flexible support (2), wherein the at least one optical detector (4) is arranged to detect light from said optical source (3), the flexible support (2) being configured to conform to a skin surface of a subject such that the at least one optical source (3) emits light into the skin and underlying tissue and the at least one optical detector (4) detects light from the at least one optical source (3) after reflection in the skin and underlying tissue, separating (103) the at least one optical source (3) and the at least one optical detector (4) on the first major surface (2a) of the flexible support (2) by (a)~wall(s) (5) being optically opaque to wavelengths implemented by the at least one optical source (3) and the at least one optical detector (4) such that the amount of light reaching the optical detector (4) directly from the optical source (3) is limited, casting (104) a biocompatible, transparent and elastic cover (6) on the first major surface (2a) of the flexible support (2), covering and embedding the optical detector (4), optical source (3) and opaque wa||(s) (5) arranged on the flexible support (2).
8. The method of claim 7, wherein the optically opaque wa||(s) (5) are arranged on the first major surface (2a) by gluing. 3
9. The method of any of claims 7 and 8, wherein prior to Casting, the optically opaque wall(s) (5) is/are treated with plasma and/or primer (105).
10. The method of any of claims 7-9, wherein the casting step (104) comprises: - providing (104a) a casting tool (10) comprising a first part (10a) arranged to receive the first major surface (2a) of the flexible support (2) and a second part (10b) arranged to form a |id over the first part (10a), - covering (104b) the insides of at least the first part (10a) of the casting tool (10) with a layer of liquid covering material, - heating (104c) the casting tool (10) with covering material until the covering material is partially cured, - arranging (104d) the flexible support (2) with the at least one optical source (3), the at least one optical detector (4) and the optically opaque wall(s) (5) arranged thereon on the partially cured covering material in the first part (10a) of the casting tool (10), - arranging (104e) the second part (10b) of the casting tool (10) on the first part (10a) covering the flexible support (2), - adding (104f) liquid covering material to the casting tool (10), - heating (104g) the casting tool (10) until the covering material is fully cured, - removing (104h) the thus formed covered optical sensor plate (1) from the casting tool (10).
11. The method of any of claims 7-10, further comprising applying (106) a coating layer (7) on the cover (6).
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE2051096A SE545864C2 (en) | 2020-09-21 | 2020-09-21 | An optical sensor plate for measuring blood flow via the skin of a patient |
| EP21773904.4A EP4213706A1 (en) | 2020-09-21 | 2021-09-15 | An optical sensor plate for measuring blood flow of a patient |
| PCT/SE2021/050884 WO2022060280A1 (en) | 2020-09-21 | 2021-09-15 | An optical sensor plate for measuring blood flow of a patient |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE2051096A SE545864C2 (en) | 2020-09-21 | 2020-09-21 | An optical sensor plate for measuring blood flow via the skin of a patient |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| SE2051096A1 SE2051096A1 (en) | 2022-03-22 |
| SE545864C2 true SE545864C2 (en) | 2024-02-27 |
Family
ID=77897698
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| SE2051096A SE545864C2 (en) | 2020-09-21 | 2020-09-21 | An optical sensor plate for measuring blood flow via the skin of a patient |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP4213706A1 (en) |
| SE (1) | SE545864C2 (en) |
| WO (1) | WO2022060280A1 (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1994012096A1 (en) * | 1992-12-01 | 1994-06-09 | Somanetics Corporation | Patient sensor for optical cerebral oximeters |
| US20060236464A1 (en) * | 2005-04-22 | 2006-10-26 | R&D Products, Llc | Multicompartmented air mattress |
| US20070021662A1 (en) * | 1996-03-05 | 2007-01-25 | Russ Delonzor | Shunt barrier in pulse oximeter sensor |
| WO2014165022A2 (en) * | 2013-03-13 | 2014-10-09 | Cephalogics, LLC | Optical tomography sensor and related apparatus and methods |
| US20180160987A1 (en) * | 2015-08-07 | 2018-06-14 | Masaki Sekino | Device for detecting blood flow disturbance |
| US20180325397A1 (en) * | 2015-11-10 | 2018-11-15 | Koninklijke Philips N.V. | Photoplethysmography device |
| EP3427657A1 (en) * | 2017-07-14 | 2019-01-16 | Koninklijke Philips N.V. | Photoplethysmographic sensor and method of producing a photoplethysmographic sensor |
| WO2019190378A1 (en) * | 2018-03-28 | 2019-10-03 | Pusensor Ab | A method and system for assessment of a blood flow |
| US20190391702A1 (en) * | 2018-06-22 | 2019-12-26 | Samsung Electronics Co., Ltd. | Sensor including first optical member with reflection property and second optical member with absorption property capable of absorbing light reflected by first optical member and electronic device including the same |
| US20200015735A1 (en) * | 2018-07-16 | 2020-01-16 | Bruin Biometrics, Llc | Perfusion and oxygenation measurement |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3769974A (en) * | 1971-06-29 | 1973-11-06 | Martin Marietta Corp | Blood pulse measuring employing reflected red light |
| CN109475328A (en) * | 2016-06-09 | 2019-03-15 | 因赛特系统公司 | For detecting the integrated light-emitting display and sensor of biological nature |
| CN111513699A (en) * | 2020-04-29 | 2020-08-11 | 维沃移动通信有限公司 | Optical assembly, electronic equipment and biological characteristic data detection method |
-
2020
- 2020-09-21 SE SE2051096A patent/SE545864C2/en unknown
-
2021
- 2021-09-15 WO PCT/SE2021/050884 patent/WO2022060280A1/en unknown
- 2021-09-15 EP EP21773904.4A patent/EP4213706A1/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1994012096A1 (en) * | 1992-12-01 | 1994-06-09 | Somanetics Corporation | Patient sensor for optical cerebral oximeters |
| US20070021662A1 (en) * | 1996-03-05 | 2007-01-25 | Russ Delonzor | Shunt barrier in pulse oximeter sensor |
| US20060236464A1 (en) * | 2005-04-22 | 2006-10-26 | R&D Products, Llc | Multicompartmented air mattress |
| WO2014165022A2 (en) * | 2013-03-13 | 2014-10-09 | Cephalogics, LLC | Optical tomography sensor and related apparatus and methods |
| US20180160987A1 (en) * | 2015-08-07 | 2018-06-14 | Masaki Sekino | Device for detecting blood flow disturbance |
| US20180325397A1 (en) * | 2015-11-10 | 2018-11-15 | Koninklijke Philips N.V. | Photoplethysmography device |
| EP3427657A1 (en) * | 2017-07-14 | 2019-01-16 | Koninklijke Philips N.V. | Photoplethysmographic sensor and method of producing a photoplethysmographic sensor |
| WO2019190378A1 (en) * | 2018-03-28 | 2019-10-03 | Pusensor Ab | A method and system for assessment of a blood flow |
| US20190391702A1 (en) * | 2018-06-22 | 2019-12-26 | Samsung Electronics Co., Ltd. | Sensor including first optical member with reflection property and second optical member with absorption property capable of absorbing light reflected by first optical member and electronic device including the same |
| US20200015735A1 (en) * | 2018-07-16 | 2020-01-16 | Bruin Biometrics, Llc | Perfusion and oxygenation measurement |
Also Published As
| Publication number | Publication date |
|---|---|
| EP4213706A1 (en) | 2023-07-26 |
| SE2051096A1 (en) | 2022-03-22 |
| WO2022060280A1 (en) | 2022-03-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20210000390A1 (en) | Epidermal Photonic Systems and Methods | |
| US6743249B1 (en) | Treatment device for photodynamic therapy and method for making same | |
| JP4767464B2 (en) | Optical device for non-invasive measurement of signals relating to blood and finger holder for the device | |
| CN106063392B (en) | Multi-part flexible enclosure for electronic devices | |
| US8329493B2 (en) | Stretchable circuit configuration | |
| JP7154499B2 (en) | Blood flow sensor and disease diagnosis system | |
| US9002192B2 (en) | Breathable physiological sensor | |
| US20070260129A1 (en) | Medical sensor and technique for using the same | |
| US9002425B2 (en) | Physiological sensor with offset adhesive layer | |
| US20090131770A1 (en) | Conformable physiological sensor | |
| EP0904006A1 (en) | Conformal wrap for pulse oximeter sensor | |
| EP2928371B1 (en) | Method for spectrophotometrically determining a blood oxygen parameter | |
| CA2168722A1 (en) | Self-aligning photoplethysmograph sensor | |
| CN104487041B (en) | Pressure-measuring system and method with vapor control | |
| JP2023182704A (en) | Method and system for assessment of blood flow | |
| WO2006104498A2 (en) | Hydrogel-supported porous semiconductor devices | |
| SE545864C2 (en) | An optical sensor plate for measuring blood flow via the skin of a patient | |
| EP3975839A1 (en) | Systems and methods for detection of pressure ulcers | |
| KR100760048B1 (en) | Measuring apparatus for dynamic foot pressure | |
| US20220313096A1 (en) | Sensor layer for determining temperature profiles on a skin surface, aid for application to a skin surface, method for producing an aid, and method for determining a relative temperature difference on a skin surface | |
| WO2023069619A1 (en) | Methods and apparatus for performing physiological measurements using diffuse optical imaging | |
| Numchaichanakij et al. | An insole point pressure monitoring system | |
| KR20230034669A (en) | Patch-type skin moisture level sensor | |
| Zhang et al. | An 8-FBGs Pressure Pad for COP Measurement of Plantar | |
| JPWO2019190378A5 (en) |