Peder C. Pedersen

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The received electrical echo signal from a pulse-echo system insonifying a planar interface was measured for varying degrees of rms roughness [0 to 0.29 mm (0 to 1.7 lambda)], angles of incidence, theta, (-7 degrees to 7 degrees), and ranges to a planar or focused transducer. The effect of varying theta is quantified in terms of the energy of the received(More)
Diabetic foot ulcers represent a significant health issue. Currently, clinicians and nurses mainly base their wound assessment on visual examination of wound size and healing status, while the patients themselves seldom have an opportunity to play an active role. Hence, a more quantitative and cost-effective examination method that enables the patients and(More)
For part I see ibid., vol.40, no.4, pp.366-372 (1993). In Part I, the encoding of the velocity and range information into the received and demodulated signals based on transmission of coherent repetitive linear sweep signals, was discussed. In the present work, two different implementations of FM Doppler systems that can be used to obtain velocity profiles(More)
Between 1961 and 1986, a number of investigators studied the propagation properties of ultrasound (US) in the lungs. These studies revealed high attenuation levels in the lung tissue at all levels of lung inflation. In contrast, some clinical investigators have, in the past decade, used US at 5 to 7.5 MHz to penetrate the collapsed lung effectively during(More)
Ultrasound imaging is a noninvasive technique well-suited for detecting abnormalities like cysts, lesions and blood clots. In order to use 3D ultrasound to visualize the size and shape of such abnormalities, effective boundary detection methods are needed. A robust boundary detection technique using a nearest neighbor map (NNM) and applicable to(More)
In-vitro measurements have been carried out for the group velocity and the attenuation, in dB/cm, in cow lung tissue. The velocity and the attenuation were measured both as a function of air content, from 32 to 68%, and as a function of frequency, from 10 to 800 KHz. The group velocity was determined from measurement of the phase difference between the(More)
The theoretical foundation is presented for velocity estimation with a pulsed wave (PW) Doppler system transmitting linear FM signals. The Doppler system possesses echo ranging capabilities and is evaluated in the context of Doppler ultrasound for blood velocity measurement. The FM excitation signal is formulated and the received signal is derived for a(More)
This work evaluates the feasibility of using 802.11 g ad hoc and 3G cellular broadband networks to wirelessly stream ultrasound video in real-time. Telemedicine ultrasound applications in events such as disaster relief and first-response triage can incorporate these technologies, enabling onsite medical personnel to receive assistance with diagnostic(More)
The angular spectrum decomposition is evaluated in terms of plane wave angular range, angular resolution, and spatial aliasing error using two-dimensional FFT (2-D FFT). The algorithm makes possible the source plane decomposition of normal velocity and pressure fields radiated by transducers of arbitrary shape, with significantly faster results achievable(More)
This work evaluates the feasibility of real-time wireless video streaming of medical ultrasound signals over 802.11g ad-hoc and 3G cellular broadband networks for disaster relief, rescue, and medical transport applications. Scalable H.264 encoded echocardiographic ultrasound image sequences were transmitted in real-time at specified image resolutions (VGA(More)