(6) Goodwill and Other Intangible Assets, net

Goodwill

For each of the years ended June 30, 2019 and June 30, 2018, we have not recorded any goodwill impairments. Changes in the carrying amount of goodwill is comprised of the following for the year ended June 30, 2019 (in thousands):


	2019
	Sleep and Respiratory Care		SaaS		Total
Balance at the beginning of the period	$	464,157	$	604,787	$	1,068,944
Business acquisition		159,623		634,697		794,320
Foreign currency translation adjustments		(6,815)		-		(6,815)
Balance at the end of the period	$	616,965	$	1,239,484	$	1,856,449

Other Intangible Assets

Other intangibles, net are comprised of the following as of June 30, 2019 and June 30, 2018 (in thousands):


	2019		2018
Developed/core product technology	$	401,842	$	205,149
Accumulated amortization		(157,651)		(115,237)
Developed/core product technology, net		244,191		89,912
Trade names		76,392		48,832
Accumulated amortization		(25,592)		(16,868)
Trade names, net		50,800		31,964
Non-compete agreements		4,218		3,288
Accumulated amortization		(2,783)		(2,283)
Non-compete agreements, net		1,435		1,005
Customer relationships		273,114		118,084
Accumulated amortization		(68,630)		(48,157)
Customer relationships, net		204,484		69,927
Patents		95,741		91,708
Accumulated amortization		(74,701)		(69,332)
Patents, net		21,040		22,376
Total other intangibles, net	$	521,950	$	215,184

Intangible assets consist of developed/core product technology, trade names, non-compete agreements, customer relationships, and patents, and we amortize them over the estimated useful life of the assets, generally between two and fifteen years. There are no expected residual values related to these intangible assets.

Refer to note 21 of the consolidated financial statements for details of acquisitions.

Amortization expense related to identified intangible assets for the years ended June 30, 2019 and June 30, 2018 was $74.9 million and $46.4 million, respectively. Amortization expense related to patents for the years ended June 30, 2019 and June 30, 2018 was $8.1 million and $8.0 million, respectively. Total estimated annual amortization expense for the years ending June 30, 2020 through June 30, 2024, is shown below (in thousands):


Fiscal Year	Amortization expense
2020	$	90,347
2021		84,424
2022		73,169
2023		53,893
2024		48,509