Abstract: A measurement system and method of manufacture can include: a pressure resistant structure; a pressure inducer coupled to the pressure resistant structure, the pressure inducer having an engaged configuration, the engaged configuration of the pressure inducer increasing pressure exerted on a portion of a user in contact with the pressure resistant structure; a light source coupled to the pressure resistant structure; an optical sensor coupled to the pressure resistant structure and configured to detect a signal from the light source; a pressure sensor coupled to the pressure resistant structure, the pressure sensor configured to detect the pressure exerted on the portion of the user in contact with the pressure inducer; and a processor coupled to the optical sensor and the pressure sensor, the processor configured to correlate volumetric data from the optical sensor with pressure data from the pressure sensor and to provide a blood pressure measurement.

Abstract: A measurement system and method of manufacture can include: a pressure resistant structure; a pressure inducer coupled to the pressure resistant structure, the pressure inducer having an engaged configuration, the engaged configuration of the pressure inducer increasing pressure exerted on a portion of a user in contact with the pressure resistant structure; a light source coupled to the pressure resistant structure; an optical sensor coupled to the pressure resistant structure and configured to detect a signal from the light source; a pressure sensor coupled to the pressure resistant structure, the pressure sensor configured to detect the pressure exerted on the portion of the user in contact with the pressure inducer; and a processor coupled to the optical sensor and the pressure sensor, the processor configured to correlate volumetric data from the optical sensor with pressure data from the pressure sensor and to provide a blood pressure measurement.

Abstract: A measurement system and method of manufacture can include: a pressure resistant structure; a pressure inducer coupled to the pressure resistant structure, the pressure inducer having an engaged configuration, the engaged configuration of the pressure inducer increasing pressure exerted on a portion of a user in contact with the pressure resistant structure; a light source coupled to the pressure resistant structure; an optical sensor coupled to the pressure resistant structure and configured to detect a signal from the light source; a pressure sensor coupled to the pressure resistant structure, the pressure sensor configured to detect the pressure exerted on the portion of the user in contact with the pressure inducer; and a processor coupled to the optical sensor and the pressure sensor, the processor configured to correlate volumetric data from the optical sensor with pressure data from the pressure sensor and to provide a blood pressure measurement.

Abstract: Described are embodiments of methods for determining physiological data, such as vital signs, by using an optical diagnostic sensor, the method comprising receiving at a semiconductor material, which is located between a photodiode and a trench, an opening into silicon, or a backside wafer-level package (WLP) coating, light of a first wavelength and light of a second wavelength that are above the wavelength of red light, the semiconductor material acting as a filter that blocks wavelengths below the wavelength of red light; detecting, at the photodiode, light of at least one of the first wavelength or the second wavelength; and using the detected light to determine a vital sign.

Abstract: Method and apparatus to enable the use of class D amplifiers without the need for an output filter, while maintaining both a high efficiency and a high audio fidelity. Using the classic differential Pulse Width Modulation scheme, the high frequency carrier is first suppressed to achieve a ternary modulation, and then re-introduced as a common mode pulse whose width is modulated to provide the necessary output voltage, but whose width never decreases below a well-defined threshold. The frequency of the modulator waveform (ramp or triangle) may itself be modulated on a sample-by-sample basis, so that the EMI spectrum of the output waveforms can be made white at high frequencies. The combination of the modulation scheme and spread spectrum high frequency behavior allows the user to eliminate the external filter. Various embodiments are disclosed.

Abstract: Method and apparatus to enable the use of class D amplifiers without the need for an output filter, while maintaining both a high efficiency and a high audio fidelity. Using the classic differential Pulse Width Modulation scheme, the high frequency carrier is first suppressed to achieve a ternary modulation, and then re-introduced as a common mode pulse whose width is modulated to provide the necessary output voltage, but whose width never decreases below a well-defined threshold. The frequency of the modulator waveform (ramp or triangle) may itself be modulated on a sample-by-sample basis, so that the EMI spectrum of the output waveforms can be made white at high frequencies. The combination of the modulation scheme and spread spectrum high frequency behavior allows the user to eliminate the external filter. Various embodiments are disclosed.

Abstract: Filterless class D amplifier using spread spectrum pulse width modulation with feedback to suppress low frequency noise in the amplifier output. The amplifiers may use any of a wide variety of pulse width modulators with a dynamically variable frequency ramp or triangular waveform to whiten the output noise of the amplifier. Typically the ramp or triangular waveform input to the modulators is randomly or pseudo randomly varied over some percentage about a nominal frequency. Various feedback techniques for suppressing the low frequency noise are disclosed. Using this invention, Electromagnetic Interference (EMI) emissions from the circuit can be kept substantially below regulatory requirements without the need for expensive external filtering and/or shielding external to the integrated circuit.