Engineered Muscle Testing Apparatus

1
Engineered Muscle Testing Apparatus

• Group 1 Michael Berry (Presenter)
• Aidan Yandell
• Danielle Senge
• Mentor
• Dr. Gregory H. Borschel, M.D.

2
Need and Background

• Muscle tissue replacement is necessary when the
  body experiences
• Traumatic injury
• Tumor ablation
• Functional damage due to myopathy
• Research suggests that engineered tissue could
  eventually serve as a replacement that functions
  similarly to natural muscle
• A method of testing engineered muscle is
  necessary for further advancement in muscle
  engineering

3
Scope

• Design a system to stimulate the contraction of
  both native and engineered muscle in vitro and
  to measure the force generated by the isometric
  contractions.
• Parameters such as muscle length, stimulation
  frequency, and stimulation strength must be
  variable in order to characterize the contractile
  properties of the muscle.

4
Design Specifications

• Temperature of muscle held at 37C
• Must be able to test samples 1.0 to 2.0 cm long
• Isometric Force Transducer
• Range 100µNlt F lt10mN
• Resolution 10 µN
• Software
• Data acquisition
• Data manipulation and plotting
• Length Tension Curves
• Force-Frequency Curves
• Force-Strength Curves

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Design Specifications Cont.

• Programmable Stimulator
• Produce tetanic and twitch contractions
• Signal must be quantifiable, variable, and
  reproducible
• Dimensions
• Be able to fit on a table top
• Less than 3 x 3
• Weight Semi-portable less than 40 lbs.
• Budget 2,000

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System Components

• Temperature Control Device
• Hot Plate
• Stimulation Device
• Programmable Voltage Source
• Electrodes
• Device for Varying Muscle Length
• Translational Stage
• Isometric Force Transducer
• Semiconductor Strain Gauge Force Transducer
• Software for data acquisition and voltage source
  control
• LabVIEW Software

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Hot Plate

• Corning 120V/60Hz Digital Hot Plate
• Model HPD120
• Feedback Controlled
• Pyroceram Top
• Range 20C to 550C
• Resolution 1C
• 5C Increments
• Plate Dimensions 5" x 7"
• Weight 6.0 lbs

http//www.thomassci.com/catalog/product/36287
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Stimulator

• Grass Tech. Square Pulse Stimulator
• Model S48
• Single or Repetitive Stimulation
• Twitch or Tetanic Contractions
• 10 mV to 150 volts
• Train Duration 1 msec to 10 sec
• Stimulus Rate up to 1000 pulses/sec
• Pulse Duration 10 µsec to 10 sec

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Stimulator Cont.

• Peak Output Current 650 mA
• AC Power 115/230 volts 50/60 Hz
• Dimensions 17.25" W x 5.25" H x 12.5" D
• Weight14 lbs

http//www.grasstechnologies.com/products/stimulat
ors/stims48.html
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Electrodes

• Chose platinum wire electrodes
• Thomas Scientific
• Platinum Wire
• 22 gauge
• Non-reactive
• Does not corrode
• Safe for voltages that will be used

http//www.thomassci.com/catalog/product/26011
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Translational Stage

• Newport MT Series MT-XY Model
• Travel (each axis) 9.5 mm
• Sensitivity 1mm 
• Load Capacity 9.6 lb
• Dimensions 1 W x 1.25 H x 1 L

http//www.newport.com/store/genproduct.aspx?id14
4540lang1033SectionDetail
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Force Transducer

• Selected a Semiconductor Strain Gauge
• Grass Technologies Force
• Displacement Transducer

http//www.grasstechnologies.com/products/transduc
ers/ft03.html
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Force Transducer Cont.

• Model FT03
• Adjustable Range
• Smallest Range 0 to 50 mN
• Resolution 10 µN
• Very high stability, accurate to 1
• Dimensions 1" W x 1.25" H x 6" L
• Weight 3 oz.

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Amplifier

• Grass Tech. Compact Transducer Amplifier
• Model P11T
• Designed specifically to work with our selected
  force transducer
• Amplifies and conditions signals
• Gain Range 100 to 30,000
• DC Coupled Input, 1 MO impedance, differential.

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Amplifier Cont.

• Output  5 volts maximum via rear panel BNC
  connector at 500 O impedance 
• Display 3-digit LCD Display
• Low Pass Filter 10, 30, or 100 Hz
• Physical Size 
• 4 W x 2.25 H x 4.5 D
• Weight 0.9 oz.

http//www.grasstechnologies.com/products/amplifie
rs/p11t.html
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Power Supply

• Grass Tech. Laboratory-grade Power System
• Model RPS210
• Designed for use with selected force transducer
  and amplifier
• Compact desktop power supply
• Operates 90 to 130 Volts AC
• Physical Size 2.3" W x 1.25" H x 4.3" L
• Weight 8 oz.

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Data Conversion

• Analog to Digital Converter
• Calculation of ADC Bit Rate
• Range of forces produced is 0 to 10 mN
• 10 µN resolution
• 10 mN / 10 µN 1,000 divisions
• 2n 1,000 ? n 10 bit (gives 1023 divisions)
• Output from Amplifier
• Range 10 Volts (-5 to 5 volts)
• 10 V / 1023 divisions 1.0 mV Resolution

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Data Conversion Cont.

• Sampling Rate
• Determining Sampling Rate
• Duration of twitch contraction 100 msec
• Sampling rate should be at least a hundred data
  points per contraction
• Selected a sampling rate of 1000 Hz
• This sampling rate creates a smooth curve when
  the data is plotted.

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Software

• Signal from force transducer amplifier will be
  sent to a PC
• LabVIEW
• Data Acquisition Capabilities
• Interfaces with Transducer/Amplifier
• Can record collected data in tables and plots
• Can display output in real time.
• Will be used to run the Voltage Source
• Code will be written to create GUI
• User can select parameters of stimulation
• Program will set limits on parameters to prevent
  unsuitable or unwise settings

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LabVIEW GUI
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Summary of Parts
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System Block Diagram
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Safety Concerns

• For User and Bystanders
• System contains heavy parts. Risk of injury if
  they fall from tabletop.
• Hot plate is a source of heat. Risk of burns if
  set to high temperatures and touched.
• Electrodes can cause electrical shock if person
  touches or comes near them while they are in use.

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Conclusion

• Did we solve the problem?
• Functional
• Over budget, but budget is flexible
• Possible Solutions
• Analog Stimulator 1000 cheaper.
• LabVIEW Academic License?
• Appropriate Size and Weight (Does not include
  Computer)
• Total weight of 25 lbs and less than 3 x 3
• What would we do differently?
• Be in better contact with our mentor.
• Scheduled a time to meet every week.
• There is no IP because there is no innovation and
  we are buying all our parts from other companies.

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References

• Keynes, R.D. and D.J. Aidley. Nerve and Muscle.
  2001
• http//sine.ni.com/nips/cds/view/p/lang/en/nid/138
  5
• http//www.grasstechnologies.com/
• products/transducers/ft03.html
• products/amplifiers/p11t.html
• grassvps.securesites.net/cgi-local/
• shop.pl/pagerps2.html/SID1165196041.14871
• http//www.thomassci.com
• http//www.corning.com/
• http//www.newport.com/store/
• genproduct.aspx?id144540lang1033SectionDetail
  
• genproduct.aspx?id144540lang1033sectionPricin
  g

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Questions?