摘要:
An apparatus for positioning a human subject on a surface and for transferring a subject from one surface to another. The subject is situated on the top surface of a fluid enclosure and an actuator mechanism causes local deformations of the top surface in such a manner as to create traveling waves whereby a force tangential to the top surface is exerted on the subject for moving the subject with respect to the surface. The actuator mechanism may be a motor driver and may be a plurality of linear actuators configured so as to cause local deformations of the top surface in a direction having a vertical and/or horizontal component. The linear actuators may be shape memory fibers.
摘要:
A hybrid personal vehicle capable of holonomic omni-directional self-locomotion. The vehicle may be programmed to navigate to a specified location in a crowded household environment. Additionally, sensors are provided for accurate docking and tight mating with fixtures such as a toilet or bed. A controller determines a docking trajectory to a specified fixture and behaves with arbitrary stiffness in each degree of freedom about a determined center of compliance.
摘要:
A reconfigurable mechanism for varying the footprint of a wheeled omnidirectional vehicle. The variable footprint mechanism consists of a pair of beams intersecting at a pivotal point in the middle. Two pairs of ball wheels at the diagonal positions of the vehicle chassis are mounted, respectively, on the two beams intersecting in the middle. The angle between the two beams varies actively so that the ratio of the wheel base to the tread may change. Independent servomotors driving the ball wheels allow the vehicle to move in an arbitrary direction from an arbitrary configuration as well as to change the angle between the two beams and thereby change the footprint. By controlling the beam angle, static stability may be augmented, the width of the vehicle may be reduced, and the effective transmission ratio relating the vehicle speed to individual actuator speeds may be varied in a continuous manner.
摘要:
An apparatus and methods for performing a circulatory measurement on an extremity, such as a hand, of a subject. The circulatory measurement results in the derivation of an output circulatory metric that may encompass blood pressure or various other circulatory metrics. An indicator of an input circulatory metric at a locus on the extremity is measured, such as a pulse transit time, and calibrated to account for the hydrostatic component of blood pressure arising due to vertical displacement of the extremity with respect to the heart.
摘要:
Methods and a computer program product for using a circulatory measurement on an extremity of a particular subject to derive an aortic blood pressure for that subject. A model is constructed that maps a peripheral cardiovascular waveform to a central cardiovascular waveform on the basis of a plurality of model parameters. A time record is obtained using a non-invasive blood pressure sensor disposed at a solitary position periphery of the cardiovascular system of a subject. The time record is then transformed to obtain a plurality of test central blood pressure waves, with a single test central blood pressure wave is based on each of a plurality of sets of values of the model parameters. An optimum set of values of the model parameters is then selected, based on a specified criterion applied to the plurality of test central blood pressure waves, so that the aortic circulatory waveform of the subject can be obtained.
摘要:
Methods and apparatus for measuring arterial blood pressure at an extremity of a subject. Arterial blood pressure is derived from a circulatory measurement performed on an extremity of a subject and the circulatory measurement is normalized to account for the instantaneous vertical displacement of the extremity. The vertical displacement of the extremity relative to the heart of the subject is obtained using the angular orientation of the subject's extremity. An improved photoplethysmograph can discriminate light traversing the extremity from ambient light on the basis of differential response. The apparatus may have a conducting polymer actuator for applying pressure to the extremity of the subject. A pulsatile waveform from the photoplethysmographic signal may be obtained at a plurality of externally applied pressures to calibrate the photoplethysmograph.
摘要:
A method and apparatus for telemetering data on a channel having a maximum data rate by utilizing a power efficient communication protocol is provided. The data to be telemetered comprises a number of source symbols where each source symbol is characterized by a probability of occurrence. A sequence of signals forming codewords having an energy and a length is produced. The length for the codewords is based at least on the number of symbols to be coded. Each codeword signifies a specified source symbol on the basis of a mapping between source symbols and codewords. The mapping is such that each source symbol of lower probability of occurrence is associated with a codeword of at least equal energy.
摘要:
A robot is placed on a first surface of a panel. The robot includes a body and first and second feet connected to the body via joints. A flux conducting device is positioned on an opposing second surface of the panel, opposite the robot, so that each foot of the robot is magnetically coupled to the flux conducting device. The flux conducting device is moved along the exterior surface to pull the robot along the interior surface until an obstacle on the first surface is encountered. The robot decouples one of the feet from the flux conducting device, lifts the decoupled foot above the obstacle, and moves the decoupled foot past the obstacle.
摘要:
A device for noninvasive, continuous monitoring of arterial blood pressure for advanced cardiovascular diagnoses. Most of the current noninvasive, continuous blood pressure measurement devices are mechanically intrusive and, therefore, cannot be used for long-term ambulatory monitoring. This new approach requires only simple, noninvasive monitoring devices such as finger photoplethysmographs and an electrical impedance photoplethysmograph (EIP) to monitor the dynamic behavior of the arterial blood flow. In this approach, measured signals from these noninvasive sensors on an arterial segment are integrated to estimate the blood pressure in the segment based on a hemodynamic model. A mathematical model of the arterial blood flow is derived and transformed into a state-space representation. In the modeling, a precise hemodynamic model for the arterial segment on which sensors are located is derived, and combined with relatively simplified models of the upstream and the downstream arterial flows to represent an entire arterial stream. Then, a Kalman filter is designed based on the model and it is shown that the internal variables such as the arterial blood pressure in the arterial segment can be estimated based on the measurements, even though the observability condition of the system may not be met. Simulation results indicate that the approach can generate an accurate estimation of the arterial blood pressure in real-time even from noisy sensor signals.
摘要:
A monitoring system for monitoring the health status of a patient by performing measurements such as skin temperature, blood flow, blood constituent concentration, and pulse rate at the finger of the patient. The monitoring system has an inner ring proximate to the finger as well as an outer ring, mechanically decoupled from the inner ring, that shields the inner ring from external loads. Measurements are performed in accordance with a protocol that may be preprogrammed, or may be modified on the basis of real-time data or by command from a remotely located medical professional.