1. Field of the Invention
The invention relates to medical patient weighing, and, more particularly, to a portable device, system and method for weighing ambulatory and non-ambulatory patients.
2. Description of the Background
It is known that persons confined to a wheelchair often need to be weighed as part of a medical check up or follow-up. For many of these individuals, stepping off a wheelchair and onto a weight scale is difficult, or impossible, to accomplish. Consequently, weighing both the wheelchair and the patient, and subtracting the weight of the wheel chair, is a practical method of weighing. This practice has become commonplace. Such a simple procedure may, in fact, be quite involved, because the weighing device must accommodate the wheelchair, which generally requires ramps and a platform scale, for example. As such, wheelchair users ordinarily are weighed at a physician's office, hospital, nursing home, clinic, or the like, using a platform scale, which weighing, due to the inconvenience of the need to travel, may occur once a month or less. Such infrequent weighing renders weight control programs quite difficult to maintain. In addition to those using wheelchairs, often those requiring crutches or walkers must be seated in wheelchairs for weighing due to the difficulty in maintaining balance on an ordinary scale while utilizing crutches or a walker.
Due to the size of platform scales, platform scales are generally found principally in clinics, hospitals, nursing homes, or rehabilitation centers with a significant number of mobility-disabled patients. Consequently, physicians rarely have office platform scales, not only because such scales occupy a disproportionate amount of floor space in relation to usage, but also because, even with foldable ramps, such scales occupy valuable storage space. Although physician's weighing chairs may be available with built-in scales, those confined to wheelchairs may find it inconvenient or dangerous to be transferred between chairs for a procedure as routine as weighing.
In response to the deficiencies inherent in available weighing systems for the mobility disabled, portable weighing devices including two laterally displaced, electrically connected and rigidly aligned weighing modules have been developed. An example of one such system is documented in U.S. Pat. No. 5,414,225. The weighing device taught therein is designed for the conventional manually-operated wheelchair supported by two front caster wheels and two rear main wheels. A notable feature of the above-referenced device is the rigidly adjustable scissors-like adjustment between the two weighing pads. The rigidly adjustable pads must be pre-extended to the correct width of the wheelchair before use. A continuously variable width adjustment would be attractive because it permits easy last-minute adjustment of the weighing pads by an operator.
Additionally, it would be advantageous if a weighing scale could be utilized by both non-ambulatory and ambulatory patients, wherein ambulatory patients could step on the scales and be weighed without the use of the wheelchair, and wherein non-ambulatory patients may be pushed onto the same scale in a wheelchair. Thus, dual purpose weighing pads could be used for both purposes, and a smaller platform scale in a doctor's office setting would not be needed.
Therefore, a need exists for a portable, fully adjustable wheelchair scale that can additionally serve as a substitute for a platform scale.