Fôring Eksperimentering Device (FED): Bygging og validering av en Open-source-enhet for måling av matinntak i Gnagere
Summary
Feeding Experimentation Device (FED) is an open-source device for measuring food intake in mice. FED can also synchronize food intake measurements with other techniques via a real-time digital output. Here, we provide a step-by-step tutorial for the construction, validation, and usage of FED.
Abstract
Food intake measurements are essential for many research studies. Here, we provide a detailed description of a novel solution for measuring food intake in mice: the Feeding Experimentation Device (FED). FED is an open-source system that was designed to facilitate flexibility in food intake studies. Due to its compact and battery powered design, FED can be placed within standard home cages or other experimental equipment. Food intake measurements can also be synchronized with other equipment in real-time via FED’s transistor-transistor logic (TTL) digital output, or in post-acquisition processing as FED timestamps every event with a real-time clock. When in use, a food pellet sits within FED’s food well where it is monitored via an infrared beam. When the pellet is removed by the mouse, FED logs the timestamp onto its internal secure digital (SD) card and dispenses another pellet. FED can run for up to 5 days before it is necessary to charge the battery and refill the pellet hopper, minimizing human interference in data collection. Assembly of FED requires minimal engineering background, and off-the-shelf materials and electronics were prioritized in its construction. We also provide scripts for analysis of food intake and meal patterns. Finally, FED is open-source and all design and construction files are online, to facilitate modifications and improvements by other researchers.
Introduction
Med fremveksten av global fedme i løpet av siste del av det 20. århundre, er det fornyet oppmerksomhet på mekanismene bak fôring 1, 2, 3, 4. Vanligvis er matinntak veies manuelt 5, eller med kommersielt tilgjengelige matesystemer. Kommersielle systemer er gode, men gir begrenset fleksibilitet i å endre sine design eller kode. Her beskriver vi Feeding Eksperimentering Device (FED): en åpen kildekode-matesystem for måling av matinntaket med fin tidsoppløsning og minimal menneskelig innblanding 6. FED er batteridrevet og fullstendig inneholdt i en 3D trykt sak som kan passe inn i standard koloni stativ bur eller annet vitenskapelig utstyr.
I sin steady state, FED opererer i en strømsparingsmodus med mat pellet hvile i sin food godt. Tilstedeværelsen av pelleten blir overvåket via en infrarød stråle. Når en mus fjerner en pellet, sender en photointerrupter sensor et signal til mikrokontrolleren og tidsstempel er logget på det innebygde Secure Digital (SD) -kort. Samtidig gir en transistor-transistor logikk (TTL) utgang en real-time produksjon av pellets henting. Umiddelbart etter denne hendelsen, motor roterer for å dispensere en annen pellet, og systemet går tilbake til lavstrømmodus. På grunn av sin åpen kildekode natur, kan FED endres og forbedres for å passe spesifikke forskningsbehov. For eksempel, kan koden være enkelt endres for å begrense mate til bestemte tider på dagen, eller for å stanse utmatning når en rekke pellets er nådd, uten behov for menneskelig påvirkning.
Her skisserer vi de trinnvise instruksjoner for bygging, validering, og bruk av FED for måling av matinntak hos mus. Vi tilbyr en liste over alle komponenter for å konstruere et system. Viktigere, ingen tidligere exerfart i elektronikk er nødvendig for å konstruere FED.
Protocol
Representative Results
Discussion
Den fôring Eksperimentering Device (FED) er en fleksibel matinntak overvåkingssystem. Her beskriver vi detaljerte instruksjoner om fabrikasjon og feilsøking på enheten, inkludert montering av 3D trykt maskinvare, lodding av elektriske komponenter, og opplasting av skisser ned på mikrokontrollere. Selv om det er viktig å følge alle trinnene i protokollen nøye, er det viktige skritt som fortjener ekstra oppmerksomhet på hver del for å sikre en vellykket sluttprodukt. 3D trykte roterende skive skal sitte tett på…
Disclosures
The authors have nothing to disclose.
Acknowledgements
Dette arbeidet ble støttet av egenutført Research Program av National Institutes of Health (NIH), The National Institute of Diabetes og Digestive og nyre sykdommer (NIDDK). Vi takker NIH Seksjon på Instrumentering og NIH biblioteket for å få hjelp med 3D-utskrift.
Materials
| Electronics | |||
| Adafruit Motor/Stepper/Servo Shield for Arduino v2 Kit – v2.3 | Adafruit | 1438 | Use of other motor shields has not been tested and will require changes to the code |
| Adafruit Assembled Data Logging shield for Arduino | Adafruit | 1141 | Use of other data logging shields has not been tested and will require changes to the code |
| PowerBoost 500 Charger | Adafruit | 1944 | Other voltge regulator boards have not been tested, but should work if they have similar specifications |
| FTDI Friend + extras – v1.0 | Adafruit | 284 | Any FTDI-USB connection will work |
| Small Reduction Stepper Motor – 5VDC 32-Step 1/16 Gearing | Adafruit | 858 | Use of other stepper motors has not been tested |
| Arduino Pro 328 – 5V/16MHz | SparkFun | DEV-10915 | Other Arduino boards should work, although may require changes to the code |
| Photo Interrupter – GP1A57HRJ00F | SparkFun | SEN-09299 | Other photointerrupters will work, but may require changes to the 3D design |
| SparkFun Photo Interrupter Breakout Board – GP1A57HRJ00F | SparkFun | BOB-09322 | Other photointerrupters will work, but may require changes to the 3D design |
| Connectors, screws, and miscellaneous items | |||
| Shield stacking headers for Arduino (R3 Compatible) | Adafruit | 85 | Any stacking header that says Arduiono R3 compatible will work |
| Multi-Colored Heat Shrink Pack – 3/32" + 1/8" + 3/16" | Adafruit | 1649 | Any heatshrink will work |
| Hook-up Wire Spool Set – 22AWG Solid Core – 6x25ft | Adafruit | 1311 | Any wire will work |
| Lithium Ion Battery Pack – 3.7V 4400mAh | Adafruit | 354 | Any 3.7V Lithium battery with a JST connector will work |
| SD/MicroSD Memory Card (8GB SDHC) | Adafruit | 1294 | Any SD card will work |
| 50 Ohm BNC Bulkhead Jack (3/8" D-Hole) | L-com | BAC70A | Any BNC bulkhead will work |
| Type 316 Stainless Steel Pan Head Phillips Sheet metal screw, No 6 size, 1/4" Length | McMaster-Carr | 90184A120 | Any screws of this specification will work |
| Type 316 Stainless Steel Pan Head Phillips Sheet metal screw, No 2 size, 1/4" Length | McMaster-Carr | 91735A102 | Any screws of this specification will work |
| Nylon 100 Degree Flat Head Slotted Machine Screw, 4-40 Thread, 1" Length | McMaster-Carr | 90241A253 | Any screws of this specification will work |
| Nylon Hex Nut, 4-40 Thread Size | McMaster-Carr | 94812A200 | Any nut of this specification will work |
| 2Pin JST M F Connector 200mm 22AWG Wire Cable | NewEgg | 9SIA27C3FY2876 | Any 2 pin connector will work for this connection |
| Metal Pushbutton – Latching (16mm, Red) | SparkFun | COM-11971 | Any push button or switch will work |
| Resistor Kit – 1/4W | SparkFun | COM-10969 | Any 1/4W resistors will work |
References
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