Abstract â–¡ 64

Pulse oximetry has been suggested as the preferred tool for continuos monitoring of patients at risk for the SIDS/ALTE/Apnea clinical complex. Technical difficulties related to difficulty of long term fixation to digits and motion artifact have precluded the practical home use of such devices. We have developed a new pulse oximeter based on reflectance technology which overcomes many of the limitations of conventional pulse oximetry which is based on transmission technology.

Methods: A prototype reflectance oximeter utilizing two LEDs and a sensor imbedded in an adhesive patch comparable to a standard ECG lead was studied. Subjects were twenty-five infants ranging from age 1-60 days, 4 children, and 10 adults. Simultaneous comparison measurements were made comparing a conventional pulse oximeter (Ohmeda 3800) attached to distal digits and a new RPO oximeter at multiple sites including arm, foot, chest, shoulder, forehead, and back. Simultaneous arterial blood gases were obtained from the adult subjects.

Results: Data were analyzed separately for the infant/children and the adult populations. 4464 data pairs were obtained from the infants/children and 2914 data pairs from the adults of oxygen saturations ranging from 75%-100%. The correlation (r) of the results from the RPO and conventional oximeters was 0.7 and 0.9 in the infant/children and adult study respectively. The mean of the differences between the saturation measurements of the two types of oximeters was 0.2 5% (± 4) in the infants/children and 0.4% (± 1.6) in the adults. Direct blood gas saturation measurements in the adults differed by a maximum of 1.5% from the oximetry measurements. Motion artifact was minimal and no skin reaction to the placement of the electrode in the various body sites occurred.

Conclusion: A new reflectance pulse oximeter (RPO) was demonstrated to have the same stability and precision as a standard transmission oximeter with the added advantage of being able to be attached and record from various body sites other than digits or ear lobes. Such an advantages allows for long term monitoring without concern for problems of application while minimizing the motion artifact inherent in recording from distal parts of extremities. Such a device holds great promise for use in home monitoring for infants at risk for SIDS

(Sponsored in part by SPO Medical Equipment Ltd.)