Pressure sensors for in vivo measurements on spinal growth plates.

A new transducer system has been developed for in vivo measurement of pressure on spinal growth plates. A model has been previously proposed for correcting spinal deformities with a staple-like implant, and this sensor will be used in vivo to quantify the pressure that alters growth in this new model of deformity and treatment. The pressure sensor die was 0.65 mm/sup 3/ and the overall packaged sensor size was 1.5 mmx4 mmx0.9 mm. The completed sensors were fully characterized by hydrostatic and compression tests, and performed linearly. The ruggedness and small package size will allow the sensor to be placed bilaterally in the annulus of porcine spinal intervertebral discs to record pressure for up to two weeks.