CONDENSED CONSOLIDATED BALANCE SHEETS (unaudited) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 351,000	$ 43,000
Receivables, net	1,778,000	1,382,000
Inventories	1,437,000	1,542,000
Prepaids and other assets	240,000	327,000
Total current assets	3,806,000	3,294,000
Long-term assets:
Rental equipment, net	594,000	656,000
Property, plant and equipment, net	2,135,000	2,200,000
Right of use assets	786,000	858,000
Other assets	47,000	47,000
Total long-term assets	3,562,000	3,761,000
TOTAL ASSETS	7,368,000	7,055,000
Current liabilities:
Accounts payable	2,699,000	1,640,000
Accrued liabilities	4,331,000	4,555,000
Current portion of long-term debt	2,618,000	2,546,000
Current lease liabilities	304,000	302,000
Customer deposits	169,000	524,000
Total current liabilities	10,121,000	9,567,000
Long-term liabilities:
Long-term debt, less current portion	269,000	269,000
Long-term lease liabilities	516,000	591,000
Deferred pension liability and other	4,098,000	3,677,000
Total long-term liabilities	4,883,000	4,537,000
Total liabilities	15,004,000	14,104,000
Stockholders' deficit:
Preferred Stock Series A - $20 stated value - 416,500 shares authorized; shares issued and outstanding: 0 in 2021 and 2020 and Preferred Stock Series B - $200 stated value - 51,000 shares authorized; shares issued and outstanding: 0 in 2021 and 2020
Common Stock - $0.001 par value - 30,000,000 shares authorized; shares issued: 13,474,116 in 2021 and 2020; shares outstanding: 13,446,276 in 2021 and 2020	13,000	13,000
Additional paid-in-capital	41,330,000	41,330,000
Accumulated deficit	(38,628,000)	(38,007,000)
Accumulated other comprehensive loss	(7,288,000)	(7,322,000)
Treasury stock - at cost - 27,840 common shares in 2021 and 2020	(3,063,000)	(3,063,000)
Total stockholders' deficit	(7,636,000)	(7,049,000)
TOTAL LIABILITIES AND STOCKHOLDERS' DEFICIT	7,368,000	7,055,000
Convertible Preferred Stock [Member] | Series A Preferred Stock [Member]
Stockholders' deficit:
Preferred Stock Series A - $20 stated value - 416,500 shares authorized; shares issued and outstanding: 0 in 2021 and 2020 and Preferred Stock Series B - $200 stated value - 51,000 shares authorized; shares issued and outstanding: 0 in 2021 and 2020
Convertible Preferred Stock [Member] | Series B Preferred Stock [Member]
Stockholders' deficit:
Preferred Stock Series A - $20 stated value - 416,500 shares authorized; shares issued and outstanding: 0 in 2021 and 2020 and Preferred Stock Series B - $200 stated value - 51,000 shares authorized; shares issued and outstanding: 0 in 2021 and 2020