The invention relates to a portable, user-specific performance measuring system, a related method for data transmission of signal quality and a corresponding computer program.
It is important to measure the functioning of the organ system and the movement of a person when training for an athletic performance, for example. The heart rate of a person, for instance, can be measured with a portable device that comprises a measuring belt to be fastened on the chest with an elastic belt and a heart rate receiver to be fastened on the wrist like a watch, which heart rate receiver serves as a receiver of measurement data and may process the measurement data.
The measuring belt consists of a flexible piece to be fastened on the chest and having a sensor for measuring an ECG signal. The sensor comprises two measuring electrodes that settle against the skin and are connected to an ECG detecting block. Instead of ECG measurement or in addition to it, it is possible to use several other sensors to measure the state of the organ system or movement of the user. These include acceleration sensors that provide information on the movements of the user.
A transmitter in the measuring belt or some other sensor may wirelessly transmit measurement data to the measurement data receiver fastened to the wrist of the user for processing therein. From the measuring belt or wrist receiver, the measurement data may be transmitted on to a computer or some other corresponding receiver for further processing.
However, there are problems associated with the measurement. Sweating during an athletic performance moistens the skin and improves its electrical conductivity, whereas at the beginning of the athletic performance the skin may be dry and have poor conductivity. In the latter case, the contact of the measuring electrodes of the measuring belt with the skin may be weak, which deteriorates the quality of the measurement signal received from the electrodes. There are also several other reasons affecting the contact between the skin and the electrodes, such as the tightness of the measuring belt, due to which the user cannot know how good or bad the contact is. It is also possible that a proper measurement signal is not received at all due to the poor contact, the measurement signal being only noise. Since the measuring result depends on the contact and the consequent quality of the measurement signal, measuring the real functioning of the user's organ system may be insecure or fail altogether, particularly at the beginning of an athletic performance.
An object of the invention is to implement a method for measurement of signal quality for a performance measuring system. This is achieved by a data transmission method during the performance of which a sensor of a portable user-specific performance measuring system is intended to be in contact with a user to generate a measurement signal relating to the functioning of the user's organ system. The method comprises receiving quality data of the measurement signal generated by the sensor; and presenting the quality of the measurement signal to the user on the basis of the quality data.
A further object of the invention is a portable user-specific performance measuring system arranged to generate a measurement signal relating to the functioning of a user's organ system when the performance measuring system is being used by the user. The performance measuring system comprises: a presentation unit arranged to receive quality data indicating the quality of the measurement signal and to present the quality of the measurement signal on the basis of the quality data.
Yet another object of the invention is a computer software product comprising encoded instructions which, loaded on a portable user-specific performance measuring system, form a computer process controlling the operation of the performance measuring system, the performance measuring system being intended to measure the functioning of a user's organ system. The computer process comprises receiving the quality data of a measurement signal generated by a sensor; and presenting the quality of the measurement signal to the user on the basis of the quality data.
Preferred embodiments of the invention are described in the dependent claim.
Several advantages are achieved with the method and performance measuring system according to the invention. The quality of the measurement signal can be presented to the user, and the user can, on the basis of these data, take measures to improve the contact and the quality of the measurement signal, if required.
The invention will now be described in greater detail in connection with preferred embodiments, referring to the attached drawings, in which
First, let us examine measurement of the signal quality with reference to
The sensor 106 may measure the functioning of the organ system. The functioning of the organ system may be represented by the heart rate etc.
When measuring the heart rate, for example, electrodes 106A, 106B of the sensor 106 may detect the voltage generated by the electrical activity of the heart muscle from the user's skin surface and generate a measurement signal, such as an ECG signal (ECG, electrocardiogram) representing the electrical activity of the heart muscle.
The measurement signal may be fed from the electrodes 106A, 106B to the ECG preamplifier 108, which can amplify the measurement signal 120 generated by the sensor 106 and feed the amplified measurement signal to the communication unit 112 and quality unit 110. The preamplifier 108 may comprise several amplification stages. ECG data, for example, may be processed in such a way that they comprise the ECG as such, a part of the ECG and/or timing data of the heart rate. The timing data may contain a timing pulse representing a predetermined part of the ECG.
To provide quality data, the quality unit 110 may measure the amplitude of the measurement signal 120. As a quality-representing property, the quality unit 110 may alternatively or additionally measure from the measurement signal the signal-to-interference ratio or the shape of the measurement signal 120 in relation to a predetermined reference shape. Here, high amplitude is good, meaning a voltage of more than 1 mV from peak to peak between the electrodes 106A, 106B. A good signal-to-interference ratio also means good quality. In this case, the low-frequency (e.g. below 10 Hz) interference has been filtered out and the measurement may be carried out in the frequency range of 10 Hz to 30 Hz. Also, the closer to the predetermined reference shape the measurement signal shape is, the better the quality of the measurement signal can be considered. The reference signal may be generated from the user's own measurement signal before the actual performance measurement. To generate the reference signal, the measurement may be carried out under predetermined conditions, such as in rest. The reference signal may be measured only once, repeatedly from time to time or every time before the actual performance measurement. The comparison may be visual or done by means of a computer program. The measurement signal shape and the predetermined reference shape can be compared by means of correlation, for example.
The communication unit 112 may comprise several successive amplification stages, such as an AGC (Automatic Gain Control) amplifier and a power amplifier. The communication unit 112 transmits as wireless data transmission a signal comprising measurement data and quality data. The measuring unit 102 may also be a transceiver, in which case the communication unit 112 may wirelessly receive signals sent by a predetermined communication party. Wireless communication may be based on magnetic pulses or radio-frequency electromagnetic radiation. The frequency of radio-frequency data transmission may be 2.4 GHz, and the data transmission may be digital data transmission, the data packet of which may have a separate field for quality data.
The processing unit 114 may be implemented by using analogue circuits, ASIC circuits (Application Specific Integrated Circuit), a digital processor, memory and computer software. The processing unit 114 may form a part of the computer of the performance measuring system 100.
As presented in
Let us now examine, with reference to
The display 130 may be, for example, an LCD display (Liquid Chrystal Display) or a row of LEDs. An LCD display may, controlled by the processing unit 114, display the quality of the measurement signal 120 graphically and/or numerically. The processing unit 114 may also control a row of LEDs serving as a presentation unit (see
The sound generator 134 may be, for example, a loud-speaker or a piezoelectric crystal generating, controlled by the processing unit 114, an audible audio signal to present the quality. The audio signal may be speech expressing the quality. Alternatively or additionally, the audio signal may be an audible call expressing quality.
Let us now examine presentation of the quality of the measurement signal 120 in the measuring unit 102 with reference to
The communication unit 112 may comprise a coil to which the preamplifier 108 may feed quality data 140 generated by the quality unit 110 and measurement data received from the sensor 106, which measurement data correspond to, for example, the heart rate when the functioning of the heart is being measured. By means of the coil, a magnetic signal to be transmitted can be generated which contains measurement data and quality data. The coil thus forms a magnetic field varying in phase with the heart rate, the quality of the heart rate being encoded amid the magnetic field. The coil of the communication unit 112 may be in inductive communication with the coil of the communication unit 122, for example, and thus the measuring unit 102 may transfer both the measurement data and the quality data to the central unit 104.
The communication unit 112 of the measuring unit 102 may also transmit the measurement data and quality data to the communication unit 122 of the central processing unit 104 as electromagnetic radiation.
The communication unit 122 of the central processing unit 104 may receive the measurement data and quality data and feed these data to the processing unit 124, which may execute a computer process according to the encoded instructions stored in the memory unit 126.
The processing unit 124 may be implemented by using analogue circuits, ASIC circuits (Application Specific Integrated Circuit), a digital processor, memory and computer software. The processing unit 124 may comprise a part of the computer of the performance measuring system 100.
By means of its communication unit 112, the measuring unit 102 may transmit to the communication unit 122 of the central processing unit 104 not only the measurement data but also the quality data that indicate the quality of the measurement signal 120, measured by the quality unit 110 of the measuring unit 102. The communication unit 122 may feed the quality data 140 to the processing unit 124, which controls, similarly to the processing unit 114 in the case of
With reference to the embodiment shown in
The method shown in
The distribution medium, in turn, may be a solution known as such for distributing a computer program, for example a medium readable by a data processing device, program-storing medium, memory readable by a data processing device, software distribution package readable by a data processing device, signal readable by a data processing device, data communication signal readable by a data processing device or compressed software package readable by a data processing device.
Once the quality of the measurement signal has been presented to the user, the user may correct the fastening, position and/or tightness of the measuring unit 102 if he/she wishes to improve the quality of the measurement signal. Additionally or alternatively, the user may also moisten the electrodes of the measuring unit and/or the skin to improve the contact and the quality of the measurement signal.
Although the invention has been described above with reference to the examples according to the attached drawings, it is clear that the invention is not restricted to them but may be modified in a plurality of ways within the scope of the attached claims.
Number | Date | Country | Kind |
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20075629 | Sep 2007 | FI | national |