Hewlett-packard Company

Enbiomedic

Other

King-Wah W Yeung

Wei-Wei Vivian Yeung

Michael Greenstein

Hewlett E Melton, Jr

Niels J Nielsen

Dana Seccombe

May Fong-Ho

Lawrence A Hand

John D Meyer

George H Corrigan

Clayton L Holstun

J Fleming Dias

Brian P Canfield

Jaime H Bohorquez

William J Lloyd

An activity detector worn on or in the vicinity of the waist detects hip-joint actions of the user, by using a proximity sensor in the activity detector to sense the separation between the activity detector housing and a body target linked by the hip joint. For example, when the housing of an activity detector adjacent to the lower abdomen incorporates one or more sensing plates of a capacitive proximity sensor, flexion, extension, abduction, or adduction of the hip joint can be detected as the separation between the sensing plates and the lower abdomen changes. Besides the lower abdomen, alternative body targets include the thigh, buttocks, etc. Besides capacitive proximity sensors, alternative proximity sensors include active infrared proximity sensors, imaging sensors, etc. The activity detector can also incorporate an accelerometer to obtain additional movement and orientation data, which can be combined with the separation data to detect more complex activities.

Wearable hip joint-action detectors

Accelerometer-based detection for controlling audio-reporting watches, resulting in button-free operation. A wristwatch can use an accelerometer to detect the orientation and/or movement of a user's wrist and subsequently activate audio time reporting, without requiring the user to find and lush a small button. For example, a talking wristwatch can use this method to automatically report the time whenever a user moves or orients his or her wrist to a natural position for listening. A position such as that in close proximity to the ear can additionally facilitate private listening without disturbing others. Furthermore, the wristwatch can report time using personalized audio time components that the user has previously recorded, so that reporting is in a custom voice or language. In such applications, accelerometer-based control of audio-reporting watches offers significant advantages over conventional means of control, particularly in terms of ease of use and durability.

Accelerometer-based control of wearable audio-reporting watches

Accelerometer-based orientation and/or movement detection for controlling wearable audio recorders, such as wrist-worn audio recorders, resulting in button-free operation of the audio recorders. Operating a button-free wearable audio recorder does not rely on conventional switches that are often small, difficult to operate, and not very reliable. A wrist-worn audio recorder can use an accelerometer to detect the natural orientation and/or movement of a user's wrist and subsequently activate a corresponding audio-recorder function, for instance recording or playback, without requiring the user to remember to activate the audio-recorder function. In addition, a wearable audio recorder with a vibration mechanism can use this method to remind a user of an undesirable repeated movement, such as restless leg movement. In such applications, and many others, accelerometer-based control of a wearable audio recorder offers significant advantages over conventional means of control, particularly in terms of ease of use and durability.

Accelerometer-based control of wearable audio recorders

A system for synchronizing data after they are collected and stored locally in sensor units in a distributed sensor system, so that wired or wireless communication is not required during a data-collection session. Each sensor unit has a local clock providing local-clock times before and after a data-collection session, and a data processor uses its local clock or a sensor unit's local clock as the reference to compute each sensor unit's time-scaling factor, which is the ratio of the elapsed reference local-clock time and the elapsed local-clock time. The data processor uses the time-scaling factor to convert each sensor unit's local-clock data-sampling times to the reference local-clock data-sampling times, and the data processor subsequently interpolates sensor data to approximate simultaneous sensor-data values at desired reference local-clock times. A physical-activity monitoring system can use this synchronization method to reduce the size, power consumption, and cost of the sensor units.

Post data-collection synchronization for approximation of simultaneous data

A technique for controlling print quality in an inkjet printer by delivering synchronized heating, non-printing pulses and printing pulses to the ink firing resistors during print firing operations such as during the printing of a swath. A temperature of the printhead substrate is measured and compared against a reference temperature during printing operations. If the measured temperature is below the reference temperature, then the printhead substrate is heated during the printing operations to bring the substrate up to the reference temperature. The heating is done by delivering synchronized heating non-printing pulses and printing pulses to the ink firing resistors during selected print firing periods, wherein either the heating pulses or the printing pulses, but not both, occur during a selected print firing period. The heating pulses are logically OR-ed with the printing pulses to achieve the synchronization.

Temperature control of thermal inkjet printheads by using synchronous

The volume of drops ejected from thermal ink jet printheads varies with the temperature of the printhead. The variation in drop volume degrades print quality by causing variations in the darkness in black and white text, the contrast of gray scale images, and variations in the chroma, hue, and lightness of color images. The present invention reduces the range of drop volume variation by reducing the range of printhead temperature variation during the print cycle by keeping the printhead temperature above a reference temperature. When the printhead temperature falls below the reference temperature during a print cycle the printhead is heated with nonprinting pulses.

Method and apparatus for reducing the size of drops ejected from a

An ink-cooled thermal ink jet printhead has an efficient heat exchanger located on the back side of the printhead that eliminates the need for heat sinks. All ink flowing to the firing chamber goes through the heat exchanger. The geometry of the heat exchanger is chosen so that almost all the residual heat absorbed by the printhead substrate is transferred to the ink as it flows to the firing chamber. Additionally, the pressure drop of the ink flowing through the heat exchanger is low enough so that it does not significantly reduce the refill rate of the firing chambers. The heat exchanger can have one or more active heat exchanger sides. The heat exchanger has little thermal mass itself and significantly reduces the thermal mass of printhead by eliminating the need for a heat sink. This reduces the warm-up time of the printhead to a fraction of a second.

Ink-cooled thermal ink jet printhead

A Self Calibrating Color Printer. The present invention enables color printers to accurately reproduce color images despite variations in ink, paper or the printing system. The calibrated printer includes a movable optical sensor assembly which first calibrates itself by measuring an included known color gamut located within the movement range of the sensor assembly. Once calibrated, the sensor assembly measures a color print test pattern newly printed by a movable color print head of the printer. An analog-to-digital converter transforms electrical signals from the sensor assembly to sensor values in digital form, enabling a printer control processor to process the measured data, thereby producing two look-up tables stored in memory: first, a color correction look-up table which adjusts image color values to account for the ink/paper variations, and second, an error diffusion look-up table which spreads color value errors at a given pixel to its neighbors. Once the printer control processor creates these two look-up tables and, the printer is able to process image data, and control the print head via its associated print head electronics to faithfully reproduce the image onto paper. The moveable sensor and associated gamut and print test pattern of the present invention provide an accurate, inexpensive and durable apparatus for calibrating any digital color printer. The Self Calibrating Color Printer disclosed and claimed in this patent applications provides an advanced, accurate and relatively inexpensive instrument for true reproduction of detailed color images.

Method and apparatus for calibrated digital printing using a four by

Piezoelectric elements in a transducer array are individually excited and used to sense the back-scattered signal from fluid flowing within an interrogation volume. The array is preferably a 2-D phased array with a pitch no greater than one-half the acoustic wavelength of the interrogation signal. By activating the transducer elements as a pattern of concentric rings as viewed from a point of interrogation, and by suitable phasing and range-gating of an interrogation signal, a substantially spherical interrogation volume (SIV) is created. The return signal from the SIV provides an isotropic indication of the speed of flow of the fluid. The focussing distance along an interrogation axis can be changed by changing either the size of the aperture created by the pattern of activated elements or their relative phasing. The interrogation direction can be angled off-axis by activating the transducer elements in a pattern of concentric ellipses. The interrogation axis itself may also be moved off-center by translating the pattern of activated elements. By deforming the activation pattern of the transducer elements from concentric rings to concentric ellipses, the long axes of ellipsoidal interrogation volumes (EIV) can be rotated. The back-scattered signals from these rotated ellipsoidal interrogation volumes indicate the direction of fluid flow.

Acoustic arrays and methods for sensing fluid flow

Pulses of ultrasound are focused in the patient's body to create an interrogation volume where a characteristic of blood flow is to be measured. The bandwidth of the back-scattered Doppler return signal is measured. In order to measure flow velocity independent of direction, the interrogation volume is generated substantially as a sphere in which the range dimension is set equal to the lateral dimensions (azimuth and elevation) of the interrogation signal. The Doppler bandwidth is then scaled to provide a direction-independent measurement of flow velocity. In order to determine the direction of flow, the interrogation volume is generated substantially as an ellipsoid. The long axis of the ellipsoidal interrogation volume is then rotated until the measured Doppler bandwidth is at a minimum, which is reached when the long axis is aligned with the flow direction. The interrogation volume is preferably rotated and translated using differential phasing of the ultrasonic signals from different transducer elements in a two-dimensional array.

Ultrasonic frequency-domain system and method for sensing fluid flow

Pulses of ultrasound are focused in the patient's body to create an interrogation volume where either the magnitude of velocity or the direction of blood flow is to be measured. The strength of the back-scattered signal is measured for each pulse and the mean squared rate of change of the envelope of the range-gated signal is estimated. In order to measure flow velocity independent of direction, the interrogation volume is generated substantially as a sphere by creating an ultrasonic wave envelope in which the components of the mean square spatial gradient are equal in all directions. The estimated mean square rate of change of the envelope of the back-scattered signal is then scaled to provide a direction-independent measurement of flow velocity. In order to determine the direction of flow, the interrogation volume is generated substantially as an ellipsoid. The long axis of the ellipsoidal interrogation volume is then rotated until the measured mean square rate of change of the envelope of the return signal is at a minimum, which is reached when the long axis is aligned with the flow direction. The interrogation volume is preferably rotated and translated using differential phasing of the ultrasonic signals from different transducer elements in a two-dimensional phased array.

Ultrasonic time-domain method for sensing fluid flow

An ultrasound probe includes an ultrasound emitter and a turbine. In one embodiment, the ultrasound emitter is a reflective surface which reflects ultrasound signals generated by a transmitter. The reflective surface reflects the ultrasound signals so that reflected ultrasound signals exit the ultrasound probe. The turbine is connected to the reflecting means. Fluid flowing through the turbine causes the turbine to rotate the reflecting means so that the reflected ultrasound signals sweep an area surrounding the ultrasound probe.

Turbine drive mechanism for steering ultrasound signals

This disclosure presents methods for controlling the temperature of a thermal ink jet and thermal printhead so that the quality of black and white printing, gray-scale printing, and color printing is improved. The methods control the average residual power of the columns of resistors so that the average residual power of an addressed column has a prescribed relationship to the average residual power of an unaddressed column. This is achieved by altering the magnitude of the drive voltages that drive the unaddressed resistors of the printhead matrix or by using nonprinting pulses. Methods for measuring the efficiency of the printhead are also presented.

Method and apparatus for controlling the temperature of thermal ink jet

This document discloses a method and apparatus for real-time control of the temperature of thermal ink jet printheads and thermal printheads through the use of nonprinting pulses. A closed-loop system produces nonprinting pulses in response to a difference between a reference temperature signal and a printhead temperature signal produced by a temperature sensor on the printhead so that the printhead operates at a constant elevated temperature. The reference temperature signal can specify an operating temperature anywhere between 10.degree. C. and 100.degree. C. above room temperature. The closed-loop system can have multiple loops with different response times so that complex nonlinear responses to changes in the printhead temperature can be obtained. The open-loop system transmits nonprinting pulses to the printhead for each printing interval that the printer does not eject a drop. Also, this document discloses a method for measuring the energy transfer characteristics of a printhead. This method is used to determine how much energy open-loop nonprinting pulses should transmit within one printing interval to the printhead to prevent fluctuations in the temperature of the printhead caused by variations in the printer output.

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Cupertino, CA, United States of America

King-Wah W Yeung