Biosensors

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Biomedical Engineering Retreat Ithaca, NY 27 July
2007
Biosensors Data for Systems Analysis During Conval
escence
Palmer Q. Bessey, MD Burn Center Weill Medical
College
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Systems Analysis in Surgical Patients
Biomedical Engineering Retreat Ithaca, NY 27
July 2007

• Systems Analysis
• .. study of a system ... in an attempt to
  elucidate its effectiveness or performance
  ... and the effect of parameter variations on
  these quantities.
• System
• Multiple components (subsystems)
• Large and complex.
• Complicated inter-relationships
• Integrity Common purpose

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Systems Analysis in Surgical Patients
Biomedical Engineering Retreat Ithaca, NY 27
July 2007

• Systems Analysis
• .. study of a system ... in an attempt to
  elucidate its effectiveness or performance
  ... and the effect of parameter variations on
  these quantities.
• System
• Multiple components (subsystems)
• Large and complex.
• Complicated inter-relationships
• Integrity Common purpose

4
The Surgical Patient is a System
Biomedical Engineering Retreat Ithaca, NY 27
July 2007

• Components (Sub-systems)
• Cardiovascular Metabolic
• Pulmonary Neurologic
• Renal Hematologic
• Gastro-intestinal Immunologic
• Large and complex.
• Complicated Inter-relationships
• Integrity. Common purpose Recovery

5
The Surgical Patient is a System
Biomedical Engineering Retreat Ithaca, NY 27
July 2007

• Altered Normal Homeostasis.
• Threats of Operation (Injury)
• Tissue Disruption Hemorrhage
• Ischemia / Hypoxia Acidosis
• Bacterial Contamination Transfusion
• Re-perfusion Hypothermia
• Complicated Inter-relationships.
• Integrity. Common purpose Recovery

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Systems Analysis in Surgical Patients
Biomedical Engineering Retreat Ithaca, NY 27
July 2007

• Task of Convalescent Care
• Guide the patient through recovery.
• Systems Analysis
• Gather and assemble performance data
• Analysis Efficacy.
• Risk assessment.
• Decision making regarding intervention

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Systems Analysis in Surgical Patients
Biomedical Engineering Retreat Ithaca, NY 27
July 2007

• Hypothesis
• The care and treatment of
• ... patients is best done
• using numerical data
• in an orderly set of rules.

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Systems Analysis in Surgical Patients
Biomedical Engineering Retreat Ithaca, NY 27
July 2007

• Data Sources
• Events Vital signs
• Nurse observations MD observations
• Physiologic measures Lab data
• Special studies Imaging
• Analysis and Decision Making
• Gathering data Multiple individuals
• Knowledge differences Efficiency

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Systems Analysis in Surgical Patients
Biomedical Engineering Retreat Ithaca, NY 27
July 2007

• Interventions
• Risk Assessment Lead time
• End point Dose Feed back
• Issues
• Time consuming Multiple steps
• Communication Incomplete data
• Error prone Delayed feed back
• Risks All interventions / monitoring
• Opportunites

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Systems Analysis Opportunities
Biomedical Engineering Retreat Ithaca, NY 27
July 2007

• More Complete Performance Data
• For any / all compents (sub-systems)
• Cardiac performance (organ perfusion)
• Respiratory work / efficacy (gas exchange)
• Blood glucose
• Hematology / Immunology
• Wound healing
• Balance usefulness vs. invasiveness
• Less invasive is better.

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Systems Analysis Opportunities
Biomedical Engineering Retreat Ithaca, NY 27
July 2007

• More Timely Data
• Point of care testing.
• Real time data
• More Efficient Decision Making
• Standardized patient care protocols.

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Hyperglycemia
Biomedical Engineering Retreat Ithaca, NY 27
July 2007

• Clinical Effects
• Impairs PMN / Immunologic defenses
• Increased incidence of infection
• Increased vascular tone / hypoperfusion.
• Increased ventilatory work (CO2 Production)
• Exaggerate hypermetabolism
• Impaired wound healing

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Biomedical Engineering Retreat Ithaca, NY 27
July 2007
Control of Hyperglycemia
Van Den Bergh, 2001
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Biomedical Engineering Retreat Ithaca, NY 27
July 2007
Control of Hyperglycemia
Van Den Bergh, 2001
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Biomedical Engineering Retreat Ithaca, NY 27
July 2007
Control of Hyperglycemia
ONGOING INSULIN DOSING
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43 yom, Sepsis, ARDS, Renal Failure 65
BSABPBD 11 - 12 Tube Feedings
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Insulin Protocol - Nursing Work
Biomedical Engineering Retreat Ithaca, NY 27
July 2007
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Insulin Protocol - Performance
Biomedical Engineering Retreat Ithaca, NY 27
July 2007
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Insulin Protocol
Biomedical Engineering Retreat Ithaca, NY 27
July 2007

• Summary and Conclusions
• N 17 patients, 99 24-hour periods
• Nutritional Intake 1,938 57 kcal/24 hr
• Total daily insulin dose 133 12 U/24 hr
• POC Glucose determinations 1,849
• Hourly POC Glucose 1,528 (83 )
• Under 60 or over 180 mg/dl 79 (4.3)
• Conclusion
• Insulin protocol safe and effective.
• Adds substantially to nursing work load.

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Systems Analysis in Surgical Patients
Biomedical Engineering Retreat Ithaca, NY 27
July 2007

• Hypothesis
• The care and treatment of
• ... patients is best done
• using numerical data
• in an orderly set of rules.

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Systems Analysis Opportunities
Biomedical Engineering Retreat Ithaca, NY 27
July 2007

• Automation
• Sheppard et al, Ann Surg, 1968.
• 154 Cardiac Surgery Patients
• BP, LAP, Urine output, Chest tube drainage.
• Automated protocol for blood infusion -- Rules
• More reliable, consistent
• More efficient
• Cost effective
• Safer