Quarterly report pursuant to Section 13 or 15(d)

Stock Based Compensation (Details)

v3.8.0.1
Stock Based Compensation (Details)
 3 Months Ended 12 Months Ended
Jan. 01, 2018
$ / shares
shares
Jan. 01, 2017
shares
May 18, 2016
grant
shares
Apr. 05, 2016
USD ($)
shares
Mar. 31, 2018
USD ($)
$ / shares
shares
Mar. 31, 2017
USD ($)
Dec. 31, 2017
USD ($)
$ / shares
shares
Annual share reserve increase (as a percent)         4.00%    
Total stock-based compensation | $         $ 242,824 $ 332,219  
Research and development              
Total stock-based compensation | $         11,497 48,852  
General and administrative              
Total stock-based compensation | $         207,382 283,367  
Sales and marketing              
Total stock-based compensation | $         $ 23,945 $ 0  
Service Based Options              
Option Activity, Number of shares              
Balance, beginning of period (in shares) 2,823,489       2,823,489    
Granted (in shares)         1,030,070    
Options exercises in period (in shares)         (143,148)    
Forfeitures (in shares)         (301,027)    
Balance, end of period (in shares)         3,409,384   2,823,489
Exercisable (in shares)         1,671,978    
Option Activity, Weighted-average exercise price              
Beginning of period (in dollars per share) | $ / shares $ 3.93       $ 3.93    
Granted (in dollars per share) | $ / shares         3.77    
Exercised (in dollars per share) | $ / shares         2.53    
Forfeitures (in dollars per share) | $ / shares         2.21    
End of period (in dollars per share) | $ / shares         4.09   $ 3.93
Exercisable (in dollars per share) | $ / shares         $ 5.03    
Option Activity, Fair value of options granted              
Grant date fair value of options granted | $         $ 2,335,255    
Option Activity, Weighted-average remaining contractual term (in years)              
Balance         9 years 5 months 23 days   7 years 3 months 15 days
Exercisable         6 years 8 months 5 days    
Aggregate intrinsic value | $         $ 3,700,000    
Fair value of options vested in period | $         $ 355,527    
Options vested (in shares)         122,932    
Per share weighted average fair value of options granted (in dollars per share) | $ / shares         $ 2.27    
Options vested weighted average grant date fair value (in dollars per share) | $ / shares         $ 2.89    
Fair value assumptions              
Expected annual dividend yield         0.00%    
Expected volatility rate, minimum         55.00%    
Expected volatility rate, maximum         65.00%    
Stock Options With Market Based Vesting Conditions              
Option Activity, Number of shares              
Balance, beginning of period (in shares) 0       0    
Granted (in shares)         500,000    
Options exercises in period (in shares)         0    
Forfeitures (in shares)         0    
Balance, end of period (in shares)         500,000   0
Exercisable (in shares)         0    
Option Activity, Weighted-average exercise price              
Granted (in dollars per share) | $ / shares         $ 4.24    
End of period (in dollars per share) | $ / shares         $ 4.24    
Option Activity, Fair value of options granted              
Grant date fair value of options granted | $         $ 1,260,000    
Option Activity, Weighted-average remaining contractual term (in years)              
Balance         9 years 11 months 27 days    
Aggregate intrinsic value | $         $ 0.00    
Per share weighted average fair value of options granted (in dollars per share) | $ / shares         $ 2.52    
Compensation not yet recognized | $         $ 1,255,068    
Period for recognition         2 years 9 months 18 days    
Fair value assumptions              
Expected annual dividend yield         0.00%    
Expected volatility         60.00%    
Expected term of options (in years)         10 years    
Risk-free interest rate         2.84%    
Restricted Stock Awards              
Award vesting period         4 years    
Total stock-based compensation | $         $ 3,047    
Compensation not yet recognized | $         $ 1,976,368    
Option Activity, Weighted-average remaining contractual term (in years)              
Period for recognition         4 years    
Non-vested RSAs Outstanding              
Beginning balance of Non-vested RSAs (in shares) 0       0    
RSAs granted (in shares)         400,000    
RSAs vested (in shares)         0    
RSAs forfeited (in shares)         0    
Ending balance of Non-vested RSAs (in shares)         400,000   0
Weighted average grant date fair value              
Nonvested RSAs weighted average grant date fair value (in dollars per share) | $ / shares             $ 0.00
Nonvested RSAs grants in period weighted average grant date fair value (in dollars per share) | $ / shares         $ 4.24    
RSAs vested in period weighted average grant date fair value (in dollars per share) | $ / shares         0.00    
Nonvested RSAs forfeitures weighted average grant date fair value (in dollars per share) | $ / shares         $ 0.00    
Minimum | Service Based Options              
Fair value assumptions              
Expected term of options (in years)         5 years    
Risk-free interest rate         2.48%    
Maximum | Service Based Options              
Fair value assumptions              
Expected term of options (in years)         6 years 3 months    
Risk-free interest rate         2.69%    
2016 Plan              
Increase in number of shares reserved for issuance (in shares)     600,000        
Common stock remaining for future issuance (in shares)         0    
2016 Plan | Stock options              
Award expiration period         10 years    
2015 Plan              
Number of grants to be made | grant     0        
Common stock remaining for future issuance (in shares)     464,476        
2011 Stock Incentive Plan              
Number of grants to be made | grant     0        
Employee Stock Purchase Plan (ESPP)              
Common stock remaining for future issuance (in shares)         826,390    
Total stock-based compensation | $             $ 3,046
Weighted average grant date fair value              
Percentage of fair market value on the lower of first day or last day of the offering period at which employees may purchase stock under the ESPP       85.00%      
Maximum portion of earning an employee may contribute to the ESPP Plan       15.00%      
Maximum annual amount of fair market value of the Company's common stock that a participant may accrue the rights to purchase | $       $ 25,000      
Shares of common stock for future issuance (in shares)       500,000      
Automatic increase to shares authorized as percentage of outstanding stock at end of preceding year       1.00%      
Increase in shares available (in shares) 312,669 94,341          
Employee | 2016 Plan | Stock options              
Award vesting period         4 years    
Director | 2016 Plan | Stock options              
Award vesting period         3 years