Heat removal loop in a mechanical arm of a surgical apparatus
A surgical apparatus comprises a flexible and/or articulated arm; a capsule-assembly that is distally connected to the arm, that comprises a liquid-tight shell defining a capsule-assembly-interior, and that has heat-producing imaging and/or electronic component(s) disposed within its interior; and a conduit-array, the conduit-array and a portion of the capsule-assembly-interior that is outside of the conduit-array collectively forming a liquid-sealed closed flow-loop for convective removal of heat from the capsule-assembly-interior, the closed flow-loop comprising arm-disposed section(s) of the conduit-array which are at least partly disposed along and/or within the arm and which collectively longitudinally span, twice and in-parallel, at least a majority of a lengthwise majority of the arm.
1 . A system for removing heat from a heat-producing component of a mechanical arm, the system comprising:
a. an inner shell surrounding the distal heat-producing component to define a capsule;
b. an inner casing disposed in the capsule to be in at least indirect thermal communication with the heat-producing component and with the inner shell, wherein an outward-facing surface of the inner casing includes grooves and/or troughs;
c. an outer shell surrounding the inner shell to form an annular gap therebetween;
d. a conduit-array, comprising respective first and second distal orifices in fluid communication with said annular gap and with each other therethrough; and
e. a circulation mechanism configured for introducing a fluid into said annular gap via said first distal orifice and for evacuating said fluid from said annular gap via said second distal orifice, such that said fluid absorbs heat generated by said heat-producing component by passing through said annular gap.
2 . The system according to claim 1 , wherein a lengthwise portion of the conduit-array is at least partly disposed within and/or along the mechanical arm so as to span at least one flexible arm section.
3 . The system of claim 1 , wherein the heat-producing component constitutes a part of an imaging arrangement.
4 . The system of claim 1 , wherein the heat-producing component constitutes a part of a chip-on-tip arrangement.
5 . The system of claim 1 , wherein the circulation mechanism comprises a pump displaced proximally from the at least one flexible arm section and mechanically coupled to the fluid.
6 . The system of claim 5 , wherein the pump is selected and the conduit-array is shaped for causing a fluid flow through the interior of the outer shell of 10 to 200 ml/sec.
7 . The system of claim 5 , wherein the pump is selected and the conduit-array is shaped for causing a fluid flow that maintains a heat transfer coefficient for convective heat transfer from a surface of the capsule to the flowing fluid during operation of the heat-producing component of between 10 and 200 W/m 2 k.
8 . The system of claim 1 , wherein a lengthwise majority of the conduit-array is disposed within the arm.
9 . The system of claim 1 , wherein the inner casing comprises a metal characterized by thermal conductivity of at least 200 W/mK.
10 . The system of claim 1 , additionally comprising a thermal gel or thermal paste disposed in the grooves and/or troughs in at least indirect thermal communication with the inner shell and with one of: the heat-producing component and the inner casing.
11 . The system of claim 10 , wherein the thermal gel or thermal paste has a thermal conductivity of more than 5 W/mK.
12 . The system of claim 1 , wherein the conduit-array comprises one or more arm-disposed section(s) of the conduit-array which, collectively, longitudinally span, twice and in-parallel, at least a lengthwise majority of the at least one flexible arm section.
13 . A method of removing heat from a flexible surgical arm, the arm having a heat-producing component disposed in a capsule-assembly connected distally to the arm, the method comprising:
a. thermally coupling, to the capsule assembly, a forced-convection heat dissipation system comprising (i) a conduit-array disposed at least partly within the arm, the conduit-array having a heat-removal fluid disposed therein and (ii) a pump mechanically coupled to the fluid for causing a flow thereof; and
b. operating the pump so as to cause the fluid to (i) flow distally through a first conduit of the conduit-array to the capsule-assembly, (ii) remove from the capsule-assembly, by forced convection, at least a portion of the heat produced by the heat-producing component and (iii) flow proximally from the capsule-assembly through a second conduit of the conduit-array to dissipate therein at least a portion of the heat removed from the capsule-assembly,
wherein (i) the capsule-assembly comprises (A) an inner shell surrounding the distal heat-producing component, (B) an inner casing disposed in the capsule to be in at least indirect thermal communication with the heat-producing component and with the inner shell, an outward-facing surface of the inner casing including grooves and/or troughs, and (C) an outer shell surrounding the inner shell to form an annular gap therebetween, and (ii) the removing at least the portion of the heat by forced convection includes circulating the fluid through the annular gap.
14 . The method of claim 13 , wherein an annular-region gap-thickness of between 0.05 mm and 0.6 mm is sustained over at least 180 degrees of capsule circumference, for at least 1 cm of length of the capsule.
15 . The method of claim 13 , additionally comprising, before the thermally coupling: applying a thermal gel or thermal paste in the grooves or troughs.
16 . Surgical apparatus comprising:
a. a flexible arm comprising an arm section configured to be flexed by at least 90°;
b. a capsule-assembly distally connected to the arm, the capsule-assembly comprising an outer shell and a capsule disposed therein so as to form an annular gap between the outer shell and the capsule, the capsule including (i) a heat-producing electronic and/or imaging component which is heat-producing during operation of the surgical apparatus, (ii) an inner shell surrounding the heat-producing component, and (iii) an inner casing disposed in the capsule to be in at least indirect thermal communication with the heat-producing component and with the inner shell, wherein an outward-facing surface of the inner casing includes grooves and/or troughs; and
c. a forced-convection heat-removal system for removing heat from the capsule-assembly, the heat-removal system comprising:
i. a conduit-array, a lengthwise portion of which being at least partly disposed within and/or along the arm so as to span at least the arm section, the conduit-array comprising respective first and second distal orifices in direct fluid communication with the capsule-assembly and in indirect fluid communication with each other through the annular gap so that when a fluid disposed within the conduit-array is caused to exit the first distal orifice into an interior of the capsule assembly, the fluid traverses the annular gap and exits therefrom into the second distal orifice, and
ii. a pump displaced proximally from the flexing-configured arm section and mechanically coupled to the fluid.
17 . The surgical apparatus of claim 16 , wherein an annular-gap thickness of between 0.05 mm and 0.6 mm is sustained over at least 180 degrees of capsule circumference, for at least 1 cm of length of the capsule.
18 . The surgical apparatus of claim 16 , wherein an annular-gap thickness of between 0.1 mm and 0.6 mm is sustained over at least 180 degrees of capsule circumference, for at least 50% of a length of the capsule.
19 . The surgical apparatus of claim 16 , additionally comprising a thermal gel or thermal paste disposed applied in the grooves and/or troughs in at least indirect thermal communication with the inner shell and with one of: the heat-producing component and the inner casing.
20 . The system of claim 19 , wherein the thermal gel or thermal paste has a thermal conductivity of more than 5 W/mK.