ALARM LAB Micropipette Motion Detection by using Optical
ALARM LAB Micro-pipette Motion Detection by using Optical Fiber Sensors Ali Fuat Ergenc Nejat Olgac University of Connecticut, Mechanical Engineering Storrs 1
ALARM LAB What is ICSI? Intracytoplasmic sperm injection is a method of fertilization. Methods of ICSI • Conventional ICSI (success rate for mouse < 10%) • Piezo-assisted ICSI (N/A for mouse) • Piezo-assisted ICSI with mercury (success rate for mouse 68%) 2
ALARM LAB Piezo-assisted ICSI Zona penetration Taking out the dissected zona Oolemma Penetration Sperm injection 3
ALARM LAB Current Setup Manipulator drive signal Current Feedback & Controller 4
ALARM LAB Control signal - Controller Computer ! Feedback? 5
ALARM LAB Feedback Mechanism Current feedback mechanism is CAMERA! • Camera is a slow feedback element. • Image processing is a difficult way to get position feedback. • Only 2 -D position can be detected by using conventional microscope and camera Why do we need fast feedback ? 6
ALARM LAB High speed movies of the pipette in the air and in the dish • 1000 fps is used for detecting the motion 7
ALARM LAB 116 m 50 m Pipette is steady 25 m Frame #4 After 3 msec 30 m Frame #2 After 1 msec Frame #5 Dissected piece After 4 msec Frame #3 After 2 msec 14 m Frame #1 18 m 10 m Zona pellucida 37 m Frames of the pipette in the dish Frame #6 After 5 msec 8
ALARM LAB After 1 msec After 2 msec Frame #5 Frame #6 After 3 msec 70 m 100 m 150 m Frame #4 210 m 380 m 50 m Frame #3 Frame #2 Frame #1 270 m 10 m Frames of the pipette in the air After 4 msec After 5 msec 9
ALARM LAB Motion of the Micro-Pipette It is shown that (Kerem Ediz, Nejat Olgac, “Micro-dynamics of the piezo-driven pipettes in ICSI”, Biomedical Engineering, IEEE Transactions on , Volume: 51) • The flexible pipette shows extensive lateral oscillations during the piercing process. • The amplitudes of the axial oscillations of the pipette tip are much smaller than the amplitudes of the lateral oscillations. 10
ALARM LAB Optical Fiber Sensor It is fast, it can detect fast oscillations of the pipette tip. It is miniature, it can be attached to the holding pipette. It is non-contact, it doesn’t have any effect to the piercing process. 11
ALARM LAB Operation Principles of the Sensor y x • x-y axes position detection is obtained by voltage differentiation of quad sensors. • z axis position detection is obtained by average light flux. 12
ALARM LAB Preliminary Experiments Transmitter fiber Detector fibers Voltage Measurements Laser Light 13
ALARM LAB Summary § Piezo impulses causes lateral oscillations at the tip of pipette. § Camera isn’t fast enough feedback element to capture all motions. § A new sensor is designed and preliminary experiments are done. 14
ALARM LAB Future Work §Development of more sensitive optical detector §Miniaturization of the fiber optic detector tip §In-situ experiments and investigating the effects of the cell on the light dispersion §The usage of the light with different wavelengths. 15
ALARM LAB Acknowledgement §This work is partly sponsored by NIH grant, number 1 R 24 RR 018934 -01 16
ALARM LAB Questions ? 17
- Slides: 17