Device for measuring a physiological parameter of a user

Abstract

A device for measuring a physiological parameter of a user carrying the device that includes a sensor having at least two sensor elements for detecting a sensor signal, a carrier configured to carry the sensor, and electrical contacts of the sensor elements that lead on, into or through the carrier. One or more frames carried by the carrier are formed around the sensor and/or the individual sensor elements, and an insulator material is filled between the one or more frames and the sensor and/or the sensor elements surrounded by a respective frame without covering a top surface of a respective sensor element facing away from the carrier.

Claims

1. A device for measuring a physiological parameter of a user carrying the device, the device comprising: an optical sensor comprising sensor elements, wherein the sensor elements comprise: at least one light emitting element, wherein the at least one light emitting element is configured to emit light to the user's skin; and at least one light receiving element, wherein the at least one light receiving element is configured to receive light reflected from the user's skin; a carrier configured to carry the optical sensor, wherein the optical sensor is located on a surface of the carrier, wherein electrical contacts of the sensor elements lead on, into, and/or through the carrier, wherein the receiver frame is located on the surface of the carrier, wherein the receiver frame separates the at least one light receiving element from the at least one light emitting element, wherein the receiver frame has a height from a surface of the carrier of that is larger than a distance between the surface of the carrier and a top surface of the at least one light receiving element; at least one emitter frame, wherein the at least one emitter frame is located on the surface of the carrier, and wherein the at least one emitter frame is formed around the at least one light emitting element; and an insulator material, wherein the insulator material is filled between the at least one emitter frame and the at least one light emitting element, wherein the insulator material is filled up to a height that is equal to or smaller than the a distance between the carrier and a top surface of the at least one light emitting element, wherein the at least one emitter frame has a height from the carrier that is smaller than the distance between the carrier and the top surface of the light emitting element, and wherein the at least one emitter frame has a height greater than zero.

2. The device as claimed in claim 1, wherein a height difference between a top edge of the receiver frame and the top surface of the at least one light receiving element is in a range from 0.1 mm to 0.5 mm.

3. The device as claimed in claim 1, wherein a height difference between a top edge of the at least one emitter frame and the top surface of the at least one light emitting element is in a range from 0.1 mm to 0.8 mm.

4. The device as claimed in claim 1, further comprising an electrical sensor comprising two skin conductance electrodes, wherein the two skin conductance electrodes are configured to contact the user's skin, and wherein the two skin conductance electrodes are configured to measure conductivity of the user's skin.

5. The device as claimed in claim 1, further comprising a processor configured to process a sensor signal detected by the optical sensor.

6. The device as claimed in claim 5, wherein the processor is arranged on the carrier on a different surface than the optical sensor.

7. The device as claimed in claim 1, wherein the insulator material is epoxy resin.

8. The device as claimed in claim 1, further comprising a fixation element configured to fix the device to the user's skin.

9. The device as claimed in claim 8, wherein the fixation element is one of a wristband, an adhesive strip, a band aid, and a strap.

10. The device as claimed in claim 1, wherein the at least one light emitting element is a light emitting diode.

11. The device as claimed in claim 1, wherein the at least one light receiving element is a photo-detector.

12. The device as claimed in claim 1, wherein a height difference between a top edge of the receiver frame and the top surface of the at least one light receiving element is in a range from 0.1 mm to 0.2 mm.

13. The device as claimed in claim 1, wherein a height difference between a top edge of the at least one emitter frame and the top surface of the at least one light emitting element is in a range from 0.2 mm to 0.5 mm.

14. A method of manufacturing a device configured to measure a physiological parameter of a user carrying the device, the method comprising: arranging an optical sensor on a surface of a carrier, wherein the optical sensor comprising sensor elements, wherein the sensor elements comprise: at least one light emitting element, wherein the at least one light emitting element is configured to emit light to the user's skin, and at least one light receiving element, wherein the at least one light receiving element is configured to receive light reflected from the user's skin; wherein each of the sensor elements has a top surface facing away from the carrier; forming electrical contacts of the sensor elements on, into, and/or through the carrier, forming at least one emitter frame on the surface of the carrier around the at least one light emitting element; and filling insulator material between the at least one emitter frame and the at least one light emitting element, wherein the insulator material is filled up to a height that is equal to or smaller than a distance between the carrier and a top surface of the at least one light emitting element, and wherein the at least one emitter frame has a height from the carrier that is smaller than the distance between the carrier and the top surface of the light emitting element, and wherein the at least one emitter frame has a height greater than zero, wherein the receiver frame separates the at least one light receiving element from the at least one light emitting element, wherein the receiver frame has a height from the surface of the carrier that is larger than a distance between the surface of the carrier and a top surface of the at least one light receiving element.

15. The method as claimed in claim 14, wherein a height difference between a top edge of the at least one emitter frame and the top surface of the at least one light emitting element is in a range from 0.1 mm to 0.8 mm.

16. The method as claimed in claim 14, wherein a height difference between a top edge of the receiver frame and the top surface of the at least one light receiving element is in a range from 0.1 mm to 0.5 mm.

17. The method as claimed in claim 14, wherein the at least one light emitting element is an LED.

18. The method as claimed in claim 14, wherein the at least one light receiving element is a photo-detector.

19. The method as claimed in claim 14, comprising arranging a processor on the carrier, wherein the processor is configured to process a sensor signal detected by the optical sensor.

20. The method as claimed in claim 19, wherein the processor is arranged on the carrier on a different surface than the optical sensor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter. In the following drawings

(2) FIG. 1 shows a cross section through a known heart rate monitoring device,

(3) FIG. 2 shows a cross section through a first embodiment of a device according to the present invention,

(4) FIG. 3 shows a cross section through a second embodiment of a device according to the present invention,

(5) FIG. 4 shows a cross section through a third embodiment of a device according to the present invention,

(6) FIG. 5 shows a cross section through a fourth embodiment of a device according to the present invention, and

(7) FIG. 6 shows a flow chart of a method of manufacturing a device according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(8) FIG. 1 shows a cross section through a known device 10 for measuring a physiological parameter of a user 1 carrying said device (FIG. 1 only shows the user's arm). It comprises a sensor 12 for measuring at least one physiological parameter of the user 1 and a case 14 housing said sensor 12. The case is held on the user's arm by a fixation 16, e.g. a wristband.

(9) The sensor 12 comprises, in this embodiment, two sensor elements 121, 122 and may be a heart rate monitoring sensor for measuring or monitoring the heart rate. But generally, the particular kind of sensor that measures one or more physiological parameters (e.g. heart rate, blood pressure, breathing rate, skin conductivity, skin humidity, etc.) is not essential for the present invention.

(10) The case 14 may be a housing, e.g. of the type of a wristband, a wristwatch or monitoring device as used e.g. in sports. The particular kind and form of case 14 is also not essential for the present invention, but mainly serves to hold the sensor 12 at a desired position with respect to the user 1 and to optionally house further elements like a battery, a processing unit, a display, a user interface, etc.

(11) In this embodiment the device 10 is implemented as a heart rate monitoring device 10 for monitoring the user's heart rate, and the sensor 12 is an optical sensor comprising a light emitting element 121 and a light receiving element 122. The principle of optical heart rate monitors relies on a light source 121 (usually a LED) that shines light inside the skin. Light is scattered in the skin, where it is absorbed more or less by blood. The light exits the skin and it is captured by light receiving element 122 (usually a photodiode). The amount of the signal on the light receiving element 122 is an indication of the blood volume. When the heart pulsates the blood volume in the skin changes and thus the signal on the light receiving element 122 changes as well. The light receiving element 122 measures thus directly the pulse in the skin and thus the heart rate. By counting the number of pulses per unit time, e.g. per 10 seconds, the number the heart beats per minute (i.e. the heart rate) is obtained.

(12) FIG. 2 shows a cross section through a first embodiment of a device 20 for measuring a physiological parameter of a user carrying said device according to the present invention. Said device 20 comprises a sensor 22 comprising at least two (here three) sensor elements 221, 222, 223 for detecting a sensor signal, wherein said sensor is an optical sensor comprising two light emitting element 221, 223, in particular two LEDs, for emitting light to the user's skin and at least one light receiving element 222, in particular a photo detector, for receiving light reflected from the user's skin. Further, the device 20 comprises a case or housing (not shown; may generally be similar or identical as the case 14 shown in FIG. 1) and a carrier 26 carrying said sensor 22. This embodiment is however not preferred for use with an optical sensor because it allows light to go directly from the light emitting elements to the light receiving element without passing through the skin.

(13) In this device 20 the distance between the carrier 26 and the top surface 221a, 223a of said light emitting elements 221, 223 is smaller than the distance between the carrier 26 and the top surface 222a said light receiving element 222, i.e. there is height distance h. This solution has the advantage that a large portion of the light from the light emitting elements 221, 223 is coupled directly (i.e. without intervention of a layer of air) towards the skin and further to the light receiving element 222. Furthermore, no light from the light emitting elements can enter the light receiving element 222 directly, without having passed through the skin.

(14) For protection of the electrical components, the electrical contacts of the light emitting element(s) and the light receiving element(s) should preferably be covered with an insulator material, such as epoxy resin. It should, however, be avoided that the insulator material covers the light emitting element(s), because otherwise the skin cannot surround the light emitting elements giving the risk of air gaps and reduced grip of the skin on the light emitting elements. A generally possible embodiment of a device 30 according to the present invention, in which epoxy 32 is brought to protect the contacts of the light emitting elements 221, 223 without covering the top surface 221a, 223a of the light emitting elements 221, 223, is depicted in FIG. 3.

(15) This embodiment can be further improved by practically bringing the epoxy 32 to cover the electrical contacts 34 of the components (i.e. the sensor elements 221, 222, 223), in such a way as to minimally interfere with a correct functioning of the sensor. Pouring of epoxy just like as shown in FIG. 3 is not optimal yet, since the epoxy may spill out. Creating additional structures to confine the epoxy is an option that allows high volume production.

(16) FIG. 4 shows a further improved embodiment of a device 40 according to the present invention. In this embodiment structures are created in the device to confine the insulator material (which is not shown in FIG. 4). In particular, in this implementation that is suited for high-volume production frames 41, 42, 43 are formed around the sensor elements 221, 222, 223 that will confine the insulator material when it is poured over the electrical contacts 34 of the sensor elements in the space 36 between the frame and the optically active parts of the sensor elements.

(17) In the embodiment shown in FIG. 4 every sensor element 221, 222, 223 is surrounded by an individual frame 41, 42, 43. In other embodiments some or all frames are combined with each other, or all sensor elements are surrounded by a common frame.

(18) To further improve such a device so that it does not negatively affect the functioning of the device it has been found that the frames 41, 43 around the light emitting elements 221, 223 are preferably lower than the top surface 221a, 223a of the light emitting elements 221, 223. In other words, in such an improved implementation the light emitting elements 221, 223, in particular each light emitting element, is surrounded by a separate emitter frame 41, 43 having a height from the carrier 26 that is smaller than or equal to the distance between the carrier 26 and the top surface 221a, 223a of the respective light emitting element 221, 223 surrounded by said emitter frame 41, 43. This can be quantified in FIG. 4 by the relation h.sub.FR-LED<h.sub.LED. Preferably, the height difference between the top edge 41a, 43a of the emitter frames and the top surface 221a, 223a of the respective light emitting element 221, 223 surrounded by said emitter frame 41, 43 is in the range from 0.1 mm to 0.8 mm, in particular in the range from 0.2 mm to 0.5 mm.

(19) Regarding the receiver frame 42 around the light receiving element 222 it is preferred that this is higher than the top surface 222a of the light receiving element 222. In other words, in such an improved implementation the receiver frames 42 has a height from the carrier 26 that is larger than the distance between the carrier 26 and the top surface 222a of the light receiving element 222 surrounded by said receiver frame 42. This can be quantified in FIG. 4 by the relation h.sub.FR-PD>h.sub.PD. Preferably, the height difference between the top edge 42a of the receiver frame 42 and the top surface 222a of the light receiving element 222 surrounded by said receiver frame 42 is in the range from 0 mm to 0.5 mm, in particular in the range from 0.1 mm to 0.2 mm.

(20) It may occur for reasons of manufacturability that only one frame wall between the light receiving element and the light emitting element is present, e.g. in cases where the light receiving element and light emitting element are close. If that is the case the frame walls of both the frames of respectively the light receiving and light emitting elements coincide. This means that the frame wall of the light emitting element will be higher than the surface of the light emitting element itself, but only at the side where the light receiving element is situated. The remainder of the frame of the light emitting element will be lower than the surface of the element itself, in accordance with the above mentioned requirements.

(21) The height of the top surface of the light emitting element(s) should be lower than the top edge 42a of frame 42 around the light receiving element. The height difference should be in the range from 0.1 to 1 mm, preferably in the range from 0.2 to 0.8 mm.

(22) As explained above, the insulator material will protect the electrical contacts 34 of the sensor elements. However, these electrical contacts 34 should further make contact with other elements, such as a driver, detection electronics, processor or power source, meaning that on the carrier 26 (which may be a PCB (Printed Circuit Board)) there are some external electrical connections to these additional electronics. FIG. 5 shows a cross section through a fourth embodiment of a device 50 according to the present invention. Said device 50 comprises such additional electronics, such as a processor 52 and a driver 54. The external electrical connections are not placed on the same surface of the carrier 26 as the sensor elements 221, 222. Otherwise the parts to which they are connected would impede good contact between the skin and the sensor elements. For instance, the external electrical connections can be placed on the side surfaces of the carrier 26.

(23) As mentioned above different kinds of sensors can be used in a device according to the present invention. For instance, in an embodiment said sensor 22 is an electrical sensor comprising two skin conductance electrodes (e.g. the sensor elements 221, 222 shown in FIG. 2) for contacting the user's skin and measuring conductivity the user's skin. Still further, two or more of sensor can generally be used in such a device, and also the number of sensor elements is not essential for the present invention.

(24) A flow chart of a method of manufacturing a device for measuring a physiological parameter as proposed herein is depicted in FIG. 6. In a first step S1 the sensor 22 comprising at least two sensor elements 221, 222 for detecting a sensor signal is arranged on the carrier 26. In a second step S2 electrical contacts of said sensor elements are formed on, into or through said carrier 26. In a third step S3 one or more frames 41, 42 are formed on said carrier 26 around said sensor 22 and/or said individual sensor elements 221, 222. In a fourth step S4 insulator material 32 is filled between said one or more frames 41, 42 and the sensor 22 and/or the sensor elements 221, 222 surrounded by the respective frame 41, 42 without covering the top surface 221a, 222a of the respective sensor element 221, 222 facing away from the carrier 26.

(25) In summary, according to the present invention a way of achieving a protection of the electrical contacts without having a negative effect on the performance of the device is proposed. For this purpose frame(s) around sensor elements is (are) used, made in such a way as to preserve the performance of the sensor. For instance, at least one of these frames helps to prevent shifting of the sensor across the skin; moreover, at least one of these frames may serve to prevent direct emitted light from entering the light receiving element. Preferably, the height of the frame around the light emitting element(s) should be smaller than the height of the surface of the light emitting element(s), with the possible exception of the side facing the light receiving element. In addition, the frame around the light receiving element(s) may be higher than the surface of the light receiving element(s).

(26) While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

(27) In the claims, the word comprising does not exclude other elements or steps, and the indefinite article a or an does not exclude a plurality. A single element or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

(28) Any reference signs in the claims should not be construed as limiting the scope.