Oxygen Control and Oxygen Control and Measure System Measure System

DevelopmentDevelopment

Divia Patel, Angie Powe, Stacey Scheib

Advisors:Dr. John PennDr. Paul King

Project DefinitionProject DefinitionThe goal of this project is to design, build,

and test a device that can monitor and control blood oxygen saturation levels.

To accomplish this goal we will obtain a unit to measure both FiO2 and SaO2. This unit will be combined with a unit and the code to measure respiration and heart rate. The obtained data will be analyzed to find a correlation.

Why care about infant Why care about infant retinopathy?retinopathy?

Retinopathy of prematurity, formerly called retrolental fibroplasia, is a disease of the retina that prevents the eye from developing properly and can lead to permanent damage and blindness.

Survival Rates for infants under 1000g.Early onset of blindness and its

repercussions.

Infant Survival Rate (less than 1000g)

0

20

40

60

80

100

1979 1985 1990

Year

Important StatisticsImportant Statistics3800 children in US affected by ROP700-800 will develop blindnessIt is the only cause of early onset so

economic implications are greater.No visual memory which affects

learning and quality of life.

Cost AnalysisCost Analysis

NICU cost among most expensive types of hospitalization

Improved monitoring results in better patient outcome and less time in hospital which leads to significant cost reductions

Median cost of treatment $49,457 with average stay of 49 days (varies inversely with birth weight)

Average cost of respiratory therapy $3112 with maximum value of $237,032

What causes What causes retinopathy?retinopathy?

In premature infants, the normal growth of the retinal vessels stops, and abnormal new vessels begin to grow; this is usually associated with fluctuation in blood oxygen levels.

Specific Problem & Our Specific Problem & Our SolutionSolution

There is still vast fluctuations in the blood oxygen saturation levels despite monitoring and control with present methods.

Our solution creates a smart monitoring system of blood oxygen saturation levels that incorporates specific protocols to adjust delivery of oxygen.

Coefficient of VariationCoefficient of VariationMeasured from blood gas analysis

(PaO2)Equals standard deviation /mean In rat and human studies 1st five

days showed tight correlation and likelihood of infant progressing to threshold ROP

What is our objective?What is our objective?Design a smart monitoring and

control system to minimize fluctuations in blood oxygen saturation levels.

Action PlanAction Plan Current Status

Literature Research Performed Established Contacts: Dr. Dan Lindstrom,

Dr. Jackie York Viewed timestamped SaO2 data from Dr.

Lindstrom Contacted Ohmeda & obtained oxycap

monitoring unit Contacted Benoit Dewant and Patrick

Norris on program code for linking Simon with oxycap monitoring unit

Obtained labtop to connect with oxycap and retain data.

Future GoalsFuture Goals Obtain timestampted FiO2, SaO2, respiratory

rate, and heart rate data for analysis Design and build smart monitoring and

control unit Get prototype breadboard and power

supplies Select optical sensor and A/D converter Sketch tentative circuit and calculate circuit

values Build analog circuit , take in vitro

measurements, and connect analog circuit to the A/D converter

Obtain oxygen sensor and oxygen blender

Future ImplicationsFuture ImplicationsStandard of care between hospitals

is differentROP numbers are very conservativePost-operative patientsFrees nurses timeDecrease NICU noise pollutionSevere Asthma PatientsDiving Equipment

Weekly Scheduled Weekly Scheduled MeetingsMeetingsAll Group Members will work

individually at their convenience.

Meet as a group: Weekly on Monday evenings @ 7pm

Group Members meet with Dr. PennWeekly on Fridays @ 12:00 p.m.

Highlight of Articles Read Highlight of Articles Read by Group Membersby Group Members

Fanconi, et al. Pulse oximetry in pediatric intensive care: Comparison with measured saturations and transcutaneous oxygen tension.The Journal of Pediatrics.

Deckardt, et al. Noninvasive arterial hemoglobin oxygen saturation versus transcutaneous oxygen tension monitoring in the preterm infant. Critical Care Medicine.

Morozoff, P.E., Evans, R.W. Closed-loop Control of SaO2 in the Neonate. Biomedical Instrumentation & Technology.

Smith, et al. Automated End-Tidal CO2 Monitoring in the Postoperative Patient

Rogowski, J. Measuring the Cost of Neonatal and Perinatal Care. Pediatrics

Dr. John Penn, Vanderbilt University