Hallym University, prof. J.M. Ahn

What is Biomedical Engineering?What is Biomedical Engineering?

안 재 목 (J.M. Ahn)

한 림 대 학 교 정보통신공학부

Hallym University, prof. J.M. Ahn

Areas of research

• Cellular and Molecular eng., Tissue Eng.– cellular bioelectricity

• Diagnostic and Diagnostic and Therapeutic EngTherapeutic Eng.

• Technology for health

Hallym University, prof. J.M. Ahn

Areas of Biophysics

• BIOPHYSICAL THEORY AND MODELING, CHANNELS, RECEPTORS, AND TRANSPORTERS

• ELECTROPHYSIOLOGY

• MEMBRANES

• MUSCLE AND CONTRACTILITY

• NUCLEIC ACIDS

• PHOTOBIOPHYSICS

• PROTEINS

• SPECTROSCOPY, IMAGING, OTHER TECHNIQUES

• CELL BIOPHYSICS

Hallym University, prof. J.M. Ahn

Cellular Bioelectricity

• Transmembrane electrical phenomena in nerve cells in the brain

• nonlinear dynamical nonlinear dynamical systemssystems

• analysis and modeling

I think, I eat, therefore I amI think, I eat, therefore I am

Hallym University, prof. J.M. Ahn

PC-based Brain Interface

DirectBrain

InterfaceComputer

Hallym University, prof. J.M. Ahn

Data acquisition

Grou

nd

Isolation

ECoG recordingup to 30 channels

0.01~100 Hz

EMG or switch

Hallym University, prof. J.M. Ahn

Cellular biophysics

• Exocytotic membrane fusion

• Bioeffect

• Bioeffect exposed to Bioeffect exposed to EMFEMF

• model secretory cells

• cellular messengers

• interaction of cell-surface receptors

Hallym University, prof. J.M. Ahn

Protein biophysics

• Proteins acquire their unique function through a specific folding of the polypeptide chain. The stability of proteins or their resistance against unfolding is typically investigated by chemical or thermal denaturation.

Domain unfolding

dZ

dZ

Elasticity

A B C

A

B

C

Hallym University, prof. J.M. Ahn

Volume conductor modelstorsoheart

Hallym University, prof. J.M. Ahn

Electrophysiology : Muscle & contractility

Sinoatrial node cell

Ventricular cell

Neuron cell

Diagnostic EngineeringECG

Hallym University, prof. J.M. Ahn

Medical Device Paradigm

On-BoardOn-BoardDiagnosisDiagnosisOn-BoardOn-BoardDiagnosisDiagnosis

Recording,Recording,AssistanceAssistanceRecording,Recording,AssistanceAssistance

• Determine if the patient is ill• Requires some form of treatment

• Assist the specialist with patient diagnosis• Avoid observer variability

Hallym University, prof. J.M. Ahn

Functional Electrical Stimulator(FES)

Hallym University, prof. J.M. Ahn

Musculoskeletal Research

• Sports medicine, injury prevention and repair/reconstruction, basic science projects to determine the function function and material properties and material properties of tissuesof tissues, and structural testing of bones and joints

Hallym University, prof. J.M. Ahn

Computational Motor Control

• Anatomical structure and muscle power of the musculoskeletal system

• Adaptations in neural control strategies

Hallym University, prof. J.M. Ahn

Therapeutic Engineering(coronary artery occlusion)

Hallym University, prof. J.M. Ahn

Artificial heart

Hallym University, prof. J.M. Ahn

Artificial Heart-continued

• Cardiac pacemaker• Implantable cardiac defibrillator(ICD)

Hallym University, prof. J.M. Ahn

Totally implantable artificial heart

• The ABIOMED total artificial heart consists of two main pumping chambers, an actuator system, batteries and control electronics.

Hallym University, prof. J.M. Ahn

Korean total artificial heart

Left Sac

Right Sac

Moving actuator

Interventricular Volume

Fixed Gear

Moving Gear

Rack(oil(80cc) + air(120cc))

<Configuration><Configuration>1) 1) moving actuatormoving actuator - brushless dc motor- brushless dc motor2) 2) right ventricleright ventricle=right sac=right sac3) 3) left ventricleleft ventricle=left sac=left sac - segmented - segmented polyurethanepolyurethane4) Interventricular space4) Interventricular space occupied by lubricatingoccupied by lubricating silicon oil and airsilicon oil and air

Hallym University, prof. J.M. Ahn

Power Processing Unit

PowerPowerProcessingProcessingUnitUnit

TelemetryTelemetry

Energy TransmissionEnergy Transmission

RechargeableRechargeableBatteryBattery

RechargeableRechargeableBatteryBattery

TelemetryTelemetry

Outside BodyOutside Body Inside BodyInside Body

SkinSkin

ImDImD

RFRF

Hallym University, prof. J.M. Ahn

Transcutaneous energy transmission

ActiveActiveswitchswitch

LoadLoadNetworkNetwork

Driver

RectificationRectification

Vin=10~20 voltsVin=10~20 volts

frequency=400 kHzfrequency=400 kHzfrequency=400 kHzfrequency=400 kHz

ImplantableImplantableDevicesDevices

DC voltage(5,12,24V)DC voltage(5,12,24V)DC voltage(5,12,24V)DC voltage(5,12,24V)

CoilsCoils

Hallym University, prof. J.M. Ahn

Energy Real system

Hallym University, prof. J.M. Ahn

RF coils

EXTERNAL COILEXTERNAL COILEXTERNAL COILEXTERNAL COIL

INTERNAL COILINTERNAL COILINTERNAL COILINTERNAL COIL

VERTICAL DISTANCE = 0.8 ~ 2 cmVERTICAL DISTANCE = 0.8 ~ 2 cmVERTICAL DISTANCE = 0.8 ~ 2 cmVERTICAL DISTANCE = 0.8 ~ 2 cm

4.5 cm4.5 cm4.5 cm4.5 cm

Hallym University, prof. J.M. Ahn

RF coil coupling

Skin thicknessSkin thickness0.8 ~ 2 cm0.8 ~ 2 cm

External CoilsExternal CoilsExternal CoilsExternal Coils

Internal CoilsInternal CoilsInternal CoilsInternal Coils

Hallym University, prof. J.M. Ahn

Animal experiments

External coilsExternal coilsExternal coilsExternal coils

Artificial HeartArtificial HeartArtificial HeartArtificial Heart

Hallym University, prof. J.M. Ahn

In vivo performance

9030105 wattswatts

100

50

75

Efficiency(%)Efficiency(%)

Hallym University, prof. J.M. Ahn

Electronic stethoscope combined with ECG

heat coil

Hallym University, prof. J.M. Ahn

Pulse oximetry & ES

Pulse oximetry

헤드폰

chestpiece

Hallym University, prof. J.M. Ahn

CONCLUSIONS

• APPLICATION TO PHYSIOLOGICAL SYSTEMS FOR THE ADVANCEMENT OF SCIENTIFIC KNOWLEDGE AND IMPROVEMENT OF CLINICAL PRACTICE