Significant Accounting Policies (Tables)

9 Months Ended

12 Months Ended

Sep. 30, 2019

Dec. 31, 2018

Accounting Policies [Abstract]

Schedule of disaggregation of revenues

	Three Months Ended September 30,				Nine Months Ended September 30,
	2019		2018		2019		2018
Units placed	$	1,104	$	1,544	$	3,350	$	4,744
Spare parts and warranties		130		73		342		222
Total Revenues	$	1,234	$	1,617	$	3,692	$	4,966

	Year Ended December 31,
	2018		2017 (1)		2016 (1)
Units placed		6,237		7,490		5,670
Spare parts and warranties		308		263		199
Total Revenues		6,545		7,753		5,869

(1) As noted above, prior period amounts have not been adjusted under the modified retrospective method.

Schedule of Contract balances

	September 30,		December 31,
	2019		2018
Trade receivable, net (1)	$	572	$	758
Deferred revenues (1) (2)	$	848	$	668

(1) Balance presented net of unrecognized revenues that were not yet collected.

(2) $223 thousand of December 31, 2018 deferred revenues balance were recognized as revenues during the nine months ended September 30, 2019.

	December 31,		December 31,
	2018		2017
Trade receivable, net	$	758	$	1,103
Short and Long term deferred revenues (1)	$	668	$	384

(1) $135 thousand of December 31, 2017 deferred revenues balance were recognized as revenues during the year ended December 31, 2018.

Schedule of concentration of credit risk

	September 30,			December 31,
	2019			2018
Customer A		19	%		*	)
Customer B		18	%		*	)
Customer C		18	%		*	)
Customer D		16	%		*	)
Customer E		14	%		*	)
Customer F		*	)		29	%
Customer G		*	)		15	%
Customer H		*	)		14	%
Customer I		*	)		13	%
Customer J		*	)		12	%

*) Less than 10%

	December 31,
	2018			2017
Customer A		*	)		14	%
Customer B		*	)		17	%
Customer C		*	)		10	%
Customer D		28	%		*	)
Customer E		15	%		*	)
Customer F		14	%		*	)
Customer G		13	%		*	)
Customer H		12	%		*	)

*) Less than 10%

Schedule of product warranty liability

	US Dollars in thousands
Balance at December 31, 2018	$	304
Provision		142
Usage		(201	)
Balance at September 30, 2019	$	245

	US Dollars in thousands
Balance at December 31, 2017	$	488
Provision		185
Usage		(369	)
Balance at December 31, 2018	$	304

Schedule of property and equipment estimated useful lives

	%
Computer equipment	20-33 (mainly 33)
Office furniture and equipment	6 - 10 (mainly 10)
Machinery and laboratory equipment	15
Field service units	50
Leasehold improvements	Over the shorter of the lease term or estimated useful life

Schedule of Black-Scholes-Merton option pricing model assumptions

	Nine Months Ended September 30,
	2019			2018
Expected volatility		57.5	%		57.07 - 61.12%
Risk-free rate		2.22	%		2.74% - 2.83%
Dividend yield		—	%		—%
Expected term (in years)		6.11			6.11
Share price	$	5.37		$	25.50 - 28.75

	December 31,
	2018			2017			2016
Expected volatility		57% - 61	%		55% - 59	%		53% - 60	%
Risk-free rate		2.74% - 2.83	%		1.78% - 2.07	%		1.16% - 1.60	%
Dividend yield		—	%		—	%		—	%
Expected term (in years)		6.11			5.31 - 6.11			5.31 - 6.11
Share price	$	25.5 - $28.75		$	32.50 - $50.00		$	170 - $297.00

Schedule of basic and diluted net loss per ordinary share

	Year ended December 31,
	2018			2017			2016
Net loss	$	(21,675	)	$	(24,717	)	$	(32,503	)
Net loss attributable to ordinary shares		(21,675	)		(24,717	)		(32,503	)
Shares used in computing net loss per ordinary shares, basic and diluted		1,472,499			808,557			527,096
Net loss per ordinary share, basic and diluted	$	(14.72	)	$	(30.57	)	$	(61.66	)