The invention relates to a sensor system, a garment and a heart rate monitor.
A user-specific portable heart rate monitor typically comprises a transmitter belt to be placed around the user's chest, which transmitter belt indicates an electrocardiogram from the surface of the user's skin and sends the electrocardiogram or a pulse characterizing a part thereof wirelessly to the central processing unit of the heart rate monitor, which typically is a wrist receiver to be placed on the user's wrist. When measuring an electrocardiogram weak voltage levels are determined from the surface of the skin, which requires a high-quality electric contact between the user's skin and the detection electronics of the transmitter belt. An electric contact of high quality typically requires that the transmitter belt is sufficiently tightly placed around the chest, an adequate amount of moisture between the transmitter belt and the skin to provide the tightness and a precise positioning of the transmission location within the area of the chest. The criteria presented above make the use of the heart rate monitor more difficult and increase the malfunctions of the heart rate monitor.
It is therefore useful to consider techniques that allow improving the quality of electrocardiogram measurement and facilitate the use of the heart rate monitor.
It is an object of the invention to implement a sensor system, a garment and a heart rate monitor in order to achieve a reliable heart rate measuring that in view of the user is easy to employ. A first aspect of the invention is a sensor system for indicating an electrocardiogram from the surface of the user's skin, and the sensor system is configured to be connected to a user-specific heart rate monitor and the sensor system comprises at least one flexible film structure comprising: a first insulation layer and at least one electric conductor layer formed on top of the first insulation layer and comprising an electrode area, which is configured to establish an electric contact with the surface of the user's skin and to generate as output an electric signal proportional to a momentary value of the electrocardiogram.
A second aspect of the invention is a garment comprising a sensor system integrated into the garment for indicating an electrocardiogram from the surface of the user's skin, and the sensor system is configured to be connected to a user-specific heart rate monitor and comprises at least one flexible film structure comprising: a first insulation layer and at least one electric conductor layer formed on top of the first insulation layer and comprising an electrode area, which is configured to establish an electric contact with the surface of the user's skin and to generate as output an electric signal proportional to a momentary value of the electrocardiogram.
A further aspect of the invention is a user-specific heart rate monitor comprising a sensor system for indicating an electrocardiogram from the surface of the skin, and the sensor system comprises at least one flexible film structure comprising: a first insulation layer and at least one electric conductor layer formed on top of the first insulation layer and comprising an electrode area, which is configured to establish an electric contact with the surface of the user's skin and to generate as output an electric signal proportional to a momentary value of the electrocardiogram.
The preferred embodiments of the invention are disclosed in the dependent claims.
The invention is based on the idea that a flexible film structure that may be integrated into the garment is used as the sensor of the heart rate monitor.
The sensor system, garment and heart rate monitor according to the invention provide several advantages. The flexible film structure allows implementing the sensor system such that the pressing sensation placed on the user's body remains insignificant. In addition, the use of the flexible film structure enables to decentralize the heart rate monitor so that for instance the transmitter unit typically used in heart rate monitors can be located far from the sensor system.
In the following the invention will be described in greater detail by means of the preferred embodiments with reference to the drawings, in which
In the example shown in
The sensor system 130 detects the electrocardiogram of the user from the surface of the user's skin and generates as output electric signals 106A, 106B, 106C proportional to a momentary value of the user's electrocardiogram. The electric signals 106A, 106B, 106C are fed into the ECG preamplifier 108.
The ECG preamplifier 108 combines and preamplifies for instance the electric signals 106A, 106B, 106C, thus generating a preamplified ECG signal, which is fed into the transmitter amplifier 110. The transmitter amplifier 110 may include several successive amplifier levels, such as an AGC (Automatic Gain Control) amplifier and power amplifier.
An amplified ECG signal is fed into the transmitter antenna 112, which generates the electromagnetic field 114 transmitting ECG information. The ECG information may comprise for instance the electrocardiogram as such, a part thereof and/or timing information on the heart rate. The timing information may comprise a timing pulse that represents the timing of a predetermined part of the ECG.
The timing information can be determined by identifying for instance a QRS complex of the ECG and by determining the timing of the QRS complex. A QRS complex can be indicated with a pulse detector, for example. The transmitter unit 102 may for instance generate a burst that corresponds to the timing of each pulse and is sent to the central processing unit 104. The central processing unit 104 receives the bursts and may for instance determine the heart rate interval between the successive bursts.
The receiver antenna 116 indicates the electromagnetic field 114 generated by the transmitter antenna 112 and generates an induced electric signal, which is fed into the receiver amplifier 118.
The receiver amplifier 118 carries out the processing of the electric signal, such as filtering and amplification. In addition the receiver amplifier 118 may comprise several successive regulating levels.
The receiver amplifier 118 feeds the electric signal into the processing unit 120, which may perform analog signal shaping of the electric signal, such as filtering and analog-digital conversion. In addition, digital processing such as digital filtering, signal shaping, ECG signal indication and ECG signal analysis can be carried out in the processing unit 120.
The value of the heart rate variable characterizing the heart rate can be determined in the processing unit 120. The heart rate variable may be a heart rate interval, a heart rate frequency, variation in heart rate interval and/or variation in heart rate frequency.
The processing unit 120 can be implemented using analog circuits, ASIC circuits (Application Specific Integrated Circuit), a digital processor, memory and computer software. The processing unit 120 may form a part of the computer in the heart rate monitor 100.
Some of the data and manager information provided in the processing unit 120 can be stored in a memory unit 122 connected to the processing unit 120. In addition the memory unit 122 may comprise encoded instructions for performing the computer process in the processing unit 120.
The user interface 124 typically comprises a display unit 126 and a display controller. The display unit 126 may comprise for instance LCD (Liquid Crystal Display) components.
The user interface 124 further comprises a keypad 128 allowing the user to feed commands into the heart rate monitor 100.
The transmitter unit 102 shown in
The central processing unit 104 typically comprises apparatus parts 116 to 128, which process the electric signal and the ECG information used in wireless data transmission and provide the user interface.
With reference to
The film structure 200A can also be referred to as a sensor. The sensor system 130 includes at least one film structure 200A.
In an embodiment the first insulation layer 204 and the second insulation layer 202 are made of polycarbonate film, the thickness of which is typically fractions of millimetres. The electric conductor layer 206 can be formed for instance by pressing carbon polymer on top of the insulation layer 202, 204, where carbon functions as a conductor. Thus a thin and bendable film structure 200A, 200B is achieved, the thickness of which is fractions of millimetres and which bends in accordance with the surface of the skin. In an embodiment the thickness 210 of the film structure 200A, 200B is smaller than 0.3 millimetres. However, the solution shown is not restricted to the thickness and materials shown. The film structure shown can also be referred to as a bendable conductor base, a flex and a flexible circuit board.
In an embodiment the first insulation layer 204 is formed of a garment material such as cloth, to which the film structure 200B is fastened. Thus the garment material opening 212 may be a lead-in through the garment material, the lead-in establishing an electric contact between the electrode area 208 and the surface of the user's skin. The lead-in may be made of electrically conducting material such as polyurethane.
In an embodiment the film structure 200A, 200B includes several electric conductor layers, which are closed between the first insulation layer 204 and the second insulation layer 202. Consequently one or more insulation layers may be provided between the conductor layers. In an embodiment the electric conductor layer 206 comprises conductor structures insulated from one another. Then the conductor structures are located on the same level.
The electric conductor layer 206 comprises an electrode area 208, which establishes an electric indirect or direct contact when used on the surface of the user's skin and generates as output an electric signal 106A, 106B, 106C proportional to a momentary value of the electrocardiogram. The second insulation layer 202 comprises at least one opening 212, through which the electrode area 208 establishes an electric contact with the surface of the user's skin. Conducting material may be provided between the surface of the skin and the electrode area.
In the embodiment shown in
In this context the impedance connection 2A to 2L refers to an impedance such as a resistive impedance between the electrodes 1A to 1J, whereby the resistance of the first impedance connection 2A to 2L may for example range between 1 kΩ to 1 MΩ, however, without being restricted to the values shown. The first impedance connection 2A to 2L and the desired impedance of the first impedance connection 2A to 2L can be achieved by connecting the electrodes 1A to 1J together for instance using an appropriate carbon polymer paste conductor pattern.
The electrodes 1A to 1J may form groups, in which successive electrodes are connected together in series. The electrodes 1A to 1J may also form a matrix structure, in which the electrodes 1A to 1J may be connected to three or four other electrodes 1A to 1J. The groups can be connected to a main conductor 402, which conducts the electric signal generated by the electrodes to an electrode output 404. The use of the groups and the impedance connection between the groups allow reducing the interference signals caused by individual areas. However, the solution shown is not restricted to the electrode configuration shown, instead the electrodes 1A to 1J can be differently connected together and to the main conductor 402 depending on the embodiment.
In the example of the film structure 400B shown in
The combiner 218 may carry out a mathematical function such as a mean or a sum from the signals obtained from the active components 6A to 6I. The combiner may be an amplifier, for example. In an embodiment the combiner 218 includes a processor and is therefore able to perform advanced signal processing operations, such as selection of signals obtained from the active components 6A to 6I and/or directly from the electrodes 1A to 1J and/or determination of the correlation between the two.
With reference to
The second insulation layer 202 may comprise an opening corresponding to the opening 212 in order to establish an electric contact between the surface of the skin and the protective area 502. The electric contact may be a direct contact or an indirect one. In the latter case conducting material may be provided between the surface of the skin and the protective area 502.
The operation of the protective area 502 is based on the fact that when an induced voltage is brought from the electrode area 208 to the differential amplifier simultaneously with the voltage of the protective area 502, the static voltage component is annulled and the dependence of the output voltage of the differential amplifier on the static voltage component remains insignificant.
In an embodiment the protective area 502 comprises protective electrodes 3A to 3F connected with a second impedance connection 4A to 4L. The resistance component of the second impedance connection 4A to 4L may range for instance between 1 kΩ to 1 MΩ, however without being restricted to the values shown. The second impedance connection 4A to 4L and the desired impedance of the second impedance connection 4A to 4L can be achieved by connecting the protective electrodes 3A to 3J together using for instance an appropriate carbon polymer paste conductor pattern. The protective area 502 can be connected to the connection structure 214 with protective input conductors 510, which may be provided with an output 508 of the protective area for instance for the ECG preamplifier 108 in the heart rate monitor.
In an embodiment the protective area 502 is connected with a third impedance connection 5A to 5G to the electrode area 208, where the impedance of the third impedance connection 5A to 5G exceeds the impedance of the first impedance connection 2A to 2L. In an embodiment the resistive component of the third impedance connection exceeds 1 MΩ. In the example shown in
The third impedance connection 5A to 5G and the desired impedance of the third impedance connection 5A to 5G can be formed for instance using an appropriate carbon polymer paste conductor pattern.
With reference to
The object of the transfer conductor film 506 is to function as a flexible conductor between the measuring point such as the user's chest and the electronics in the heart rate monitor such as the transmitter unit 102. In such a case the transmitter unit 102 can be freely located for instance within the area of the pelvis or within another appropriate area of the user's body, where the transmitter unit 102 can appropriately be placed.
The transfer conductor film 506 shown in
Still referring to
Instead of the signal amplifier 504 an impedance converter can be used in an embodiment when no amplification exists or when the amplification is <1.
With reference to
What is shown as an aspect of the invention is a garment comprising a sensor system 130 integrated into the garment for indicating an electrocardiogram from the surface of the user's skin.
In an embodiment the garment comprises at least one contact element 814A, 814B, 816 for establishing an electric contact from the electric conductor layer 806, 808 on the surface of the user's skin. The contact elements 814A, 814B shown in the Figure are contact elements of the electrode area 208, whereby the contact elements 814A, 814B may be connected for instance to the electrodes 1A to 1J shown in
In accordance with
In the example shown the differential amplifier connection 900 comprises a first input 908A, a second input 908B and a third input 908C. The second input 908B can be connected to the potential of the protective area 502 of the sensors that may be the ground level. The second input 908B can also be connected to a separate ground electrode, which may be located anywhere on the surface of the skin. A signal obtained from the electrode area 208 of the first sensor can be fed into the first input 908A. A signal obtained from the electrode area 208 of the second sensor can be fed into the third input 908C. The differential amplifier connection 900 provides a voltage 910 proportional to the potential difference of the signals generated as output in the electrode area 208 of said two sensors.
Instead of the differential amplifier connection 900 a one-sided voltage amplifier that lacks a voltage follower 902B can be used in one embodiment. Then the signals obtained from the electrode areas 502 of different sensors are fed into the first input 908A.
Let us with reference to
In the examples shown in
In the embodiment shown in
If the sensors 922A, 922B include active elements 6A to 6I, 218 and/or the amplifier 504, then the operating voltage of the active elements 6A to 6I, 218 and/or the amplifier 504 can be fed from the transmitter unit 928.
In the embodiment shown in
If the sensors 922A, 922B include active elements 6A to 6I, 218 and/or the amplifier, then the operating voltage of the active elements 6A to 6I, 218 and/or the amplifier 504 can be fed from the central processing unit 932.
Although the invention has above been described with reference to the example shown in the accompanying drawings it is apparent that the invention is not restricted thereto but can be amended in various ways within the scope of the accompanying claims.
Number | Date | Country | Kind |
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20045503 | Dec 2004 | FI | national |
This application is a divisional of U.S. application Ser. No. 11/314,746, filed on Dec. 21, 2005, which claims priority based on Finnish Patent Application No. 20045503, filed on Dec. 28, 2004, which are incorporated herein by reference.
Number | Date | Country | |
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Parent | 11314746 | Dec 2005 | US |
Child | 12695608 | US |