摘要:
The invention relates to a method and apparatus for processing a cyclic physiological signal (30, 40, 52, 53, 54). The method comprises the steps of repeatedly collecting (2) the physiological signal (30, 40, 52, 53, 54) over a time period (31, 32, 33) covering two or more cycles of the cyclic physiological signal (30, 40, 52, 53, 54), wherein a next time period (31, 32, 33) is adjacent to or overlaps with a previous time period (31, 32, 33), extracting values (3, 13) of a set of predefined parameters from the physiological signal (30, 40, 52, 53, 54) within each time period (31, 32, 33) which parameter values characterize the physiological signal (30, 40, 52, 53, 54) within the time period (31, 32, 33), and classifying (4, 14) the physiological signal (30, 40, 52, 53, 54) within each time period (31, 32, 33) based upon the extracted set of predefined parameter values. This provides for an efficient analysis of a cyclic physiological signal which is especially suitable for continuous monitoring of patients where a trend of a reliable physiological signal is more important than an instantaneous measurement of a reliable physiological signal, such as in a general ward environment of a hospital and/or in a home environment.
摘要:
The invention relates to a motion determination apparatus for determining motion of a moving object, wherein the motion determination apparatus (1) comprises a multi-axial accelerometer (2) for being positioned at the moving object (4), wherein the multi-axial accelerometer (2) is adapted to generate accelerometer signals indicative of the acceleration along different spatial axes. The motion determination apparatus further comprises a motion signal generation unit (3) for generating a motion signal indicative of the motion of the object (4) by combining the accelerometer signals of different spatial axes. The combination of the accelerometer signals of different spatial axes yields a motion signal having a large signal-to-noise ratio, even if an axis is located close to a rotational axis of the movement.
摘要:
The invention relates to a method and apparatus for processing a cyclic physiological signal (30, 40, 52, 53, 54). The method comprises the steps of repeatedly collecting (2) the physiological signal (30, 40, 52, 53, 54) over a time period (31, 32, 33) covering two or more cycles of the cyclic physiological signal (30, 40, 52, 53, 54), wherein a next time period (31, 32, 33) is adjacent to or overlaps with a previous time period (31, 32, 33), extracting values (3, 13) of a set of predefined parameters from the physiological signal (30, 40, 52, 53, 54) within each time period (31, 32, 33) which parameter values characterize the physiological signal (30, 40, 52, 53, 54) within the time period (31, 32, 33), and classifying (4, 14) the physiological signal (30, 40, 52, 53, 54) within each time period (31, 32, 33) based upon the extracted set of predefined parameter values. This provides for an efficient analysis of a cyclic physiological signal which is especially suitable for continuous monitoring of patients where a trend of a reliable physiological signal is more important than an instantaneous measurement of a reliable physiological signal, such as in a general ward environment of a hospital and/or in a home environment.
摘要:
The invention relates to a system and a method in which an electrophysiological signal is sensed capacitively with at least two closely spaced electrodes such that the electrodes experience strongly correlated skin-electrode distance variations. To be able to derive a motion artifact signal, the capacitive coupling between the electrodes and skin is made intentionally different. With a signal processing means the motion artifact signal can be removed from the measured signal to leave only the desired electrophysiological signal. Since the measured quantity is dependant on the electrode-skin distance itself, the system and method do not need to rely on the constancy of a transfer function. Hereby, they give reliable motion artifact free output signals.
摘要:
This invention relates to an activity monitoring system adapted to eliminate passive movement components caused by external forces from readout data produced by a first and a second motion sensor when attached to a subject during movement. The readout data include gravitational components, movement components caused by active movement of the subject or subject parts, and the passive movement components. A processor estimates first and second gravitational components produced by the at least first and a second motion sensors. It determines a rotation matrix based on the estimated gravitational components, the rotation matrix denoting rotation required for the first sensor to get aligned with the second sensor in orientation. It then multiplies the readout data produced by the first motion sensor with the rotation matrix when rotating the first sensor towards the second sensor. Finally, it subtracts the result of the multiplying from the readout data produced by the second motion sensor when rotating the first motion sensor towards the second motion sensor.
摘要:
A loss of performance of slicer adaptation at high capacities due to the mismatch between the exact bits used in the computation of the RDS for the DC-control on the one hand and the often erroneous threshold decisions that are preliminarily made based on the HF waveform on the other hand, is resolved by performing a new method of DC- control at the encoder: the RDS is modified such that it is not based on the exact channel bits, but on the threshold decisions from a synthetic HF signal waveform that is generated based on a nominal MTF (modulation transfer function) or its IRF (impulse response function) of the channel. In this way, the impact of the erroneous threshold decisions in the receiver are already taken into account at the encoder, and the slicer control is no longer negatively affected thereby.
摘要:
The invention discloses an optical recording drive for recording data on an optical carrier such as an optical disk of the DVD or BD format. A radiation source is arranged to emit a write pulse train (80) for writing an optically detectable effect (90) i.e. a pit or mark. Photo detection means (10) detects a first reflected radiation beam pulse (R1) from a start time portion of the write pulse train (80) and generates a corresponding first signal (PS1) indicative of the power in the first pulse, the photo detection means (10) further detects a second reflected radiation pulse (R2) from an end time portion of the write pulse train (80) and generates a corresponding second signal (PS2) indicative of the power in the second pulse. By comparing (e.g. the heights of) the first signal (PS1) and the second signal (PS2), it is possible to get an indication of the received power in the optically detectable effect (90) as delivered by a power level (81; 82) in the write pulse train (80) continuously during writing and for a broad range of carrier rotation speeds.
摘要:
A method of controlling the positioning of an objective lens of a lens system for controlling an optical beam used in reading and/or recording information from/onto a track of an optical disc, the method comprising steps of detecting modulated optical signals corresponding to the intensity of a reflected optical beam, the reflected optical beam being modulated by the periodic structures of the track of the optical disc, deriving a radial tilt error signal from the modulated optical signals indicative of a radial tilt, wherein the radial tilt refers to the tilt of the objective lens with respect to the optical disc in a radial direction; using the radial tilt error signal for adjusting the position of the objective lens with respect to the optical disc in a radial direction, the method characterized by using the radial tilt error signal for adjusting the position of the objective lens by means of a feedback loop. The radial tilt error signal may be proportional to a cross correlation signal between a Radial Push Pull (RPP) signal and a Central Aperture (CA) signal or a cross correlation signal between a Radial Push Pull (RPP) and a Diagonal Push Pull (DPP) signal.
摘要:
A device is arranged for scanning an optical record carrier (11), which has a data layer with parallel data tracks. The device has an optical head (22) comprising a detector for receiving radiation reflected from a data track, the detector having sub-detectors arranged in a quadrant. The device has a tilt unit (32) for generating a tilt signal representing a tilt angle (204) between an optical axis (202) of the optical head and a perpendicular (203) of the data layer. The tilt unit (32) generates a diagonal push-pull signal based on a difference of a first signal of a first diagonally positioned pair of sub detectors and second signal of a second diagonally positioned pair of sub detectors, and processes the diagonal push-pull signal for generating the tilt signal.