Blood/Air Mass Exchange Apparatus

• US 20090081079A1
• Filed: 10/10/2008
• Published: 03/26/2009
• Est. Priority Date: 04/13/2006
• Status: Active Grant

• Current Assignee: Haemair Limited
• Original Assignee: Haemair Limited
• Inventors: Johns, William Richard
• Granted Patent: US 8,529,834 B2
• Time in Patent Office: Days
• US Class Current: 422/46
• CPC Class Codes: A61M 1/1678 intracorporal peritoneal dialysis A61M1/28
• CPC Class Codes: A61M 1/1698 Blood oxygenators with or without heat-exchangers intracorporal A61M1/1678; manufacturing of membranes therefor B01D67/00; semi-permeable membranes for separation processes characterised by their properties B01D69/00; semi-permeable membranes characterised by their material B01D71/00
• CPC Class Codes: A61M 1/3623 Means for actively controlling temperature of blood
• CPC Class Codes: A61M 1/3659 Cannulae pertaining to extracorporeal circulation
• CPC Class Codes: A61M 2202/0208 Oxygen
• CPC Class Codes: A61M 2202/0225 Carbon oxides, e.g. Carbon dioxide
• CPC Class Codes: A61M 2205/07 having air pumping means
• CPC Class Codes: A61M 2205/366 by liquid heat exchangers
• CPC Class Codes: A61M 2230/06 Heartbeat rate only
• CPC Class Codes: A61M 2230/202 partial carbon oxide pressure, e.g. partial dioxide pressure (P-CO2)
• CPC Class Codes: A61M 2230/205 partial oxygen pressure (P-O2)
• CPC Class Codes: A61M 2230/40 Respiratory characteristics

Abstract

There is provided a mass exchange apparatus (114) for use in blood/air mass exchange comprising plural blood flow conduits for defining a blood flow from a blood flow inlet provided thereto; and plural air flow conduits for defining an air flow from an air flow inlet provided thereto. The plural air flow conduits and plural blood flow conduits at least partially comprise gas-permeable membrane material, and the conduits are arranged relative to each other such as to enable transfer of oxygen from the air flow to the blood flow and transfer of carbon dioxide from the blood flow to the air flow through the membrane material. The apparatus additionally comprises at least one sensor (170) for sensing patient respiratory demand; and a controller (160) for controlling the rate of blood/air mass exchange by separate control of the levels of carbon dioxide and oxygen in the air flow responsive to the sensing of patient respiratory demand by the sensor.

Claims

1-65. -65. (canceled)

66. A mass exchange apparatus for use in blood/air mass exchange comprising

(a) plural blood flow conduits for defining a blood flow from a blood flow inlet provided thereto;

and

(b) plural air flow conduits for defining an air flow from an air flow inlet provided thereto;

wherein said plural airflow conduits and said plural blood flow conduits at least partially comprise gas-permeable membrane material, and the conduits are arranged relative to each other such as to enable transfer of oxygen from said air flow to said blood flow and transfer of carbon dioxide from said blood flow to the air flow through said membrane material,

and wherein said apparatus additionally comprises

(c) a sensor for sensing patient respiratory demand; and

(d) a controller for controlling the rate of blood/air mass exchange by separate control of the levels of carbon dioxide and oxygen in the air flow responsive to the sensing of patient respiratory demand by the sensor.

67. A mass exchange apparatus according to claim 66, wherein said controller separately controls the level of carbon dioxide and oxygen in the air flow at the air flow inlet.

68. A mass exchange apparatus according to claim 66, additionally comprising a blood flow controller for control of the flow rate of the blood flow.

69. A mass exchange apparatus according to claim 68, wherein said blood flow controller controls the flow rate of the blood flow to be proportional to the blood flow rate through the heart and major veins of a patient.

70. A mass exchange apparatus according to claim 66, wherein the airflow inlet is arranged to receive a fluid flow comprising at least an inert fluid, oxygen and carbon dioxide.

71. A mass exchange apparatus according to claim 70, additionally comprising an air recycle loop, and wherein the airflow inlet receives both a primary air flow feed and a recycled air flow feed from said air recycle loop.

72. A mass exchange apparatus according to claim 71, wherein the controller acts to control the relative proportions of primary air flow feed and recycled air flow feed received at the air flow inlet.

73. A mass exchange apparatus according to claim 72, wherein the controller acts to control the recycle rate of the air recycle loop.

74. A mass exchange apparatus according to claim 72, wherein the controller acts to control the relative feed rate of the primary air flow feed and recycled air flow feed.

75. A mass exchange apparatus according to claim 70, wherein the air flow inlet receives plural fluid flow feeds selected from the group consisting of an inert gas feed, an oxygen feed, a carbon dioxide feed and an air feed.

76. A mass exchange apparatus according to claim 75, wherein the air flow inlet receives three fluid flow feeds comprising an inert gas feed, an oxygen feed and a carbon dioxide feed.

77. A mass exchange apparatus according to claim 75, wherein the airflow inlet receives two or three fluid flow feeds, each of which contains one or more of the components oxygen, carbon dioxide and an inert fluid.

78. A mass exchange apparatus according to claim 75, wherein the controller acts to control the relative, proportions of each of the plural fluid flow feeds received at the air flow inlet.

79. A mass exchange apparatus according to claim 78, wherein the controller acts to control the relative flow rates of each of the plural fluid flow feeds received at the air flow inlet.

80. A mass exchange apparatus according to claim 75, additionally containing a secondary mass exchanger to extract carbon dioxide and replenish oxygen in the exhaust from the mass exchange apparatus,

81. A mass exchange apparatus according to claim 66, comprising plural sensors-for sensing patient respiratory demand.

82. A mass exchange apparatus according to claim 81, wherein each of said plural sensors senses a different parameter related to patient respiratory demand.

83. A mass exchange apparatus according to claim 66, wherein the sensor or at least one of the plural sensors senses the pulse rate of a patient.

84. A mass exchange apparatus according to claim 66, wherein the sensor or at least one of the plural sensors senses the breathing rate of a patient.

85. A mass exchange apparatus according to claim 66, wherein the sensor or at least one of the plural sensors senses the blood circulation rate of a patient.

86. A mass exchange apparatus according to claim 66, wherein the sensor or at least one of the plural sensors senses the oxygen concentration in venous blood of a patient.

87. A mass exchange apparatus according to claim 66, wherein the sensor or at least one of the plural sensors senses the strength of the pulse of a patient.

88. A mass exchange apparatus according to claim 66, wherein the sensor or at least one of the plural sensors senses blood oxygen saturation.

89. A mass exchange apparatus according to claim 66, wherein the sensor or at least one of the plural sensors is an electronic sensor and communication with the controller is via wired or wireless electronic transmission means.

90. A mass exchange apparatus according to claim 66, wherein the air flow is arranged to be a combination of air flow that is counter-current to the blood flow and air flow that is co-current to the blood flow.

91. A mass exchange apparatus according to claim 66, wherein the blood flow conduits and/or air flow conduits take the form of tubes or closely-spaced plates.

92. A mass exchange apparatus according to claim 91, wherein the blood flow conduits and/or air flow conduits have a diameter and/or spacing of less than 0.5 millimetres.

93. A mass exchange apparatus according to claim 91, wherein the blood flow conduits and air flow conduits are defined by a series of plates that are separated by a distance of less than 0.5 millimetres.

94. A mass exchange apparatus according to claim 66, wherein the apparatus defines a total mass-exchange area of from 2 to 25 square metres.

95. A mass exchange apparatus according to claim 66, wherein the apparatus defines a total mass-exchange area of from 1 to 5 square metres.

96. An association of plural mass exchange apparatus according to claim 66, wherein said association of apparatus defines a combined mass-transfer area of from 1 to 25 square metres.

97. A respiratory aid apparatus for external connection to a patient comprising

(a) at least one mass exchange apparatus according to claim 66;

(b) an air pump for pumping air through said air conduits to define the air flow; and

(c) a blood pump for pumping blood through said blood conduits to define the blood flow.

98. A respiratory aid apparatus according to claim 97, additionally comprising an air filter for filtering the air.

99. A respiratory aid apparatus according to claim 97, comprising two mass exchange apparatus arranged in parallel fashion.

100. A respiratory aid apparatus according to claim 97, additionally comprising a humidifier for humidifying the air.

101. A respiratory aid apparatus according to claim 97, wherein input tubing to said blood pump is arranged to provide blood extraction and return via a single entry point in a vein of a patient.

102. A respiratory aid apparatus according to claim 101, wherein said input tubing is arranged concentrically.

103. A respiratory aid apparatus according to claim 101, wherein said input tubing comprises two tubes in side-by-side arrangement and received within a third tube of circular cross-section.

104. A respiratory aid apparatus according to claim 97, arranged such that extracted blood undergoes counter-current heat transfer with returned blood.

105. A respiratory aid apparatus according to claim 97, additionally comprising a heat exchange apparatus for preheating the air,

106. An intermediate respiratory aid apparatus for internal connection to a patient comprising

(a) at least one mass exchange apparatus according to claim 66;

and

(b) an air pump for pumping air through said air conduits.

107. An intermediate respiratory aid apparatus according to claim 106, wherein said at least one mass exchange apparatus is arranged to connect directly with a vein of a patient.

108. A mixed-flow mass exchange apparatus for use in mass exchange comprising

(a) plural blood flow conduits for defining a blood flow from a blood flow inlet to a blood flow outlet provided thereto;

and

(b) plural air flow conduits for defining an air flow from an air flow inlet to an air flow outlet provided thereto;

wherein said plural blood flow conduits and said plural airflow conduits at least partially comprise gas-permeable membrane material, and the conduits are arranged relative to each other such as to enable transfer of carbon dioxide from said blood flow to said air flow and transfer of oxygen from the air flow to the blood flow through said membrane material,

and wherein said apparatus additionally comprises an adjuster that enables independent adjustment of the concentration of the carbon dioxide and oxygen in the blood flow.

109. A mixed-flow mass exchange apparatus according to claim 108, wherein the adjuster locates at either the blood flow inlet/outlet or the air flow inlet/outlet.

110. A mixed flow mass exchange apparatus according to claim 108, wherein the adjuster comprises an air flow adjuster for adjusting the total flow rate of the air flow.

111. A mixed-flow mass exchange apparatus according to claim 110, wherein said air flow adjuster comprises a valve and/or pump.

112. A mixed flow mass exchange apparatus according to claim 108, wherein the adjuster comprises a flow selector for selecting the relative flow pattern of the blood flow and the airflow.

113. A mixed-flow mass exchange apparatus according to claim 112, wherein the relative flow pattern is selected from the group consisting of co-current flow, counter-current flow, a mixed flow that is partly cross-current and partly co-current and a mixed flow that is partly cross-current and partly counter-current.

114. A mixed flow mass exchange apparatus according to claim 112, wherein said flow selector comprises a multi-way valve.

115. A mixed flow apparatus according to claim 114, wherein an airflow inlet multi-way valve enables separation of the air flow into plural separate airflows for directing to plural separate air flow inlets of the plural airflow conduits.

116. A mixed flow apparatus according to claim 114, wherein an air flow outlet multi-way valve enables separation of the air flow into plural separate air flows for directing from plural separate outlets of the plural air flow conduits.

117. A mixed flow apparatus according to claim 114, wherein a blood flow inlet multi-way valve enables separation of the blood flow into plural separate blood flows for directing to plural separate blood flow inlets of the plural blood flow conduits.

118. A mixed flow apparatus according to claim 114, wherein a blood outlet multi-way valve enables separation of the blood flow into plural separate blood flows for directing from plural separate blood flow outlets of the plural blood flow conduits.

119. A mixed flow apparatus according to claim 108, wherein the adjuster acts under the control of a controller acting in response to a sensor for sensing patient respiratory demand.

120. A mass exchange apparatus according to claim 119, comprising plural sensors for sensing patient respiratory demand.

121. A mass exchange apparatus according to claim 120, wherein each of said plural sensors senses a different parameter related to patient respiratory demand.

122. A mass exchange apparatus according to claim 119, wherein the sensor or at feast one of the plural sensors senses the pulse rate of a patient.

123. A mass exchange apparatus according to claim 119, wherein the sensor or at least one of the plural sensors senses the breathing rate of a patient.

124. A mass exchange apparatus according to claim 119, wherein the sensor or at least one of the plural sensors senses the blood circulation rate of a patient.

125. A mass exchange apparatus according to claim 119, wherein the sensor or at least one of the plural sensors senses the oxygen concentration in venous blood of a patient.

126. A mass exchange apparatus according to claim 119, wherein the sensor or at least one of the plural sensors senses the strength of the pulse of a patient.

127. A mass change apparatus according to claim 119, wherein the sensor or at least one of the plural sensors senses blood oxygen saturation.

128. A mass exchange apparatus according to claim 119, wherein the sensor or at least one of the plural sensors is an electronic sensor and communication with the controller is via wired or wireless electronic transmission means.

129. Use of the mixed-flow mass exchange apparatus of claim 108 for blood oxygenation so that blood oxygen and carbon dioxide concentrations can be separately controlled.

130. Use of the mixed-flow mass exchange apparatus of claim 108 in which one or both phases are replaced by other fluids and in which one or both of oxygen and carbon dioxide is replaced by other soluble components.