We intend to build and test a unique precision patient bed scale system (PBSS) to improve the accuracy, precision, resolution and usefulness of weighing patients in a bed or a chair. legs, and uses a unique dynamic technique to measure patient-bed weight. The dynamic measurement technique provides a means to include self-diagnostics for the sensors and electronics. This system has the potential of improving the accuracy of measuring patient weight by as much as a factor of 50 when compared to commercial patient-bed weighting systems. The PBSS is intended for patients who are temporarily or permanently incapacitated and cannot be transferred from a bed to a scale easily, comfortably, or conveniently. Its precision, sensitivity and dynamic range will permit the early detection and treatment of fluid imbalances; and its accuracy, the longer-term follow-up of nutritional problems. These applications are most relevant to the management of patients in intensive care units with their heavy, extensively instrumented beds; bed ridden on pediatric or adult hospital, rehabilitation, or extended care nursing floors; confined to special beds such as Stryker frames; undergoing inpatient and outpatient rental dialysis; or in premature nurseries. Additionally, the PBSS can be used to continuously monitor patient activity while in bed. A team consisting of a technical manager, a physician, and several design and test engineers will combine their expertise to (10 design, construct and test a low-cost precision plezoelectric load cell, (20 formulate a suitable design for the pneumatic lift system and (30 fabricate and test a prototype unit. In phase one research, the prototype system will be tested using a commercial hospital bed. The PBSS represents a significant advancement in high capacity, high resolution, rugged patient-bed weighting systems. This system can be retrofitted to any commercial hospital bed, crib, incubator, or reclining chair without interfering with patient care or the operation of the bed.