ABSTRACT
The current US healthcare system, focused mostly on acute and episodic care, has difficulty meeting the needs of ill, frail elderly and their families or other caregivers. Because of their low mobility and complex medical conditions, these "oldest old" patients and their families or caregivers must make frequent, difficult, and expensive trips to multiple physicians to receive care. The result is that the frail elderly most often receive delayed or crisis care rather than timely primary care. To address these and other needs, a coordinated approach to the care of the oldest old requires a new model that includes primary medical care in the home. This article discusses how the Medical House Call Program (MHCP) model can provide high-quality primary healthcare to the frail elderly at home, improve the continuity of care between the home and the hospital, provide support and education to families or caregivers, and provide linkage to a broad range of social and supportive services in the community. The MHCP model is one of a number of evolving for-profit and nonprofit approaches that seek to provide medical care in the home. This article also discusses how the MHCP model, working with oncology physicians and programs, can have similar benefits and applications for the growing number of elderly cancer patients and their families or caregivers.
Subject(s)
Frail Elderly , Health Services for the Aged/organization & administration , Home Care Services, Hospital-Based/organization & administration , Homebound Persons , House Calls , Models, Organizational , Oncology Service, Hospital/organization & administration , Patient Care Team , Aged , Aged, 80 and over , Ambulatory Care Information Systems , Female , Humans , Male , Physician-Patient Relations , Professional-Family Relations , Program Development , Social Support , United StatesABSTRACT
Different methods were compared for constructing models of the behavior of a prototype intermetallic compound, nickel aluminide, for use in radiation hydrodynamics simulations of shock wave generation by ablation induced by laser energy. The models included the equation of state, ionization, and radiation opacity. The methods of construction were evaluated by comparing the results of simulations of an ablatively generated shock wave in a sample of the alloy. The most accurate simulations were obtained using the "constant number density" mixture model to calculate the equation of state and opacity, and Thomas-Fermi ionization. This model is consistent with that found to be most accurate for simulations of ablatively shocked elements.
ABSTRACT
The Trident laser was used to induce shock waves in samples of solid elements, with atomic numbers ranging from Be to Au, using pulses of 527 nm light around 1 ns long with irradiances of the order of 0.1 to 10 PW/m(2). States induced by the resulting ablation process were investigated using laser Doppler velocimetry to measure the velocity history of the opposite surface. By varying the energy in the laser pulse, relations were inferred between the irradiance and the induced pressure. For samples in vacuo, an irradiance constant in time does not produce a constant pressure. Radiation hydrodynamics simulations were used to investigate the relationship between the precise pulse shape and the pressure history. In this regime of time and irradiance, it was possible to reproduce the experimental data to within their uncertainty by including conductivity-dependent deposition of laser energy, heat conduction, gray radiation diffusion, and three temperature hydrodynamics in the treatment of the plasma, with ionizations calculated using the Thomas-Fermi equation. States induced in the solid sample were fairly insensitive to the details of modeling in the plasma, so Hugoniot points may be estimated from experiments of this type given a reasonable model of the plasma. More useful applications include the generation of dynamic loading to investigate compressive strength and phase transitions, and for sample recovery.
