Patent Publication Number: US-2022233795-A1

Title: Low pressure insufflation manifold assembly for surgical gas delivery system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The subject application is a continuation-in-part of U.S. application Ser. No. 17/155,478 filed Jan. 22, 2021, and a continuation-in-part of U.S. application Ser. No. 17/155,572 filed Jan. 22, 2021, the disclosures of which are both herein incorporated by reference in their entireties. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The subject invention is directed to minimally invasive surgery, and more particularly, to a low pressure insufflation manifold assembly of a surgical gas delivery system used for gas sealed insufflation and gas recirculation during an endoscopic or laparoscopic surgical procedure. 
     2. Description of Related Art 
     Laparoscopic or “minimally invasive” surgical techniques are becoming commonplace in the performance of procedures such as cholecystectomies, appendectomies, hernia repair and nephrectomies. Benefits of such procedures include reduced trauma to the patient, reduced opportunity for infection, and decreased recovery time. Such procedures within the abdominal (peritoneal) cavity are typically performed through a device known as a trocar or cannula, which facilitates the introduction of laparoscopic instruments into the abdominal cavity of a patient. 
     Additionally, such procedures commonly involve filling or “insufflating” the abdominal cavity with a pressurized fluid, such as carbon dioxide, to create an operating space, which is referred to as a pneumoperitoneum. The insufflation can be carried out by a surgical access device, such as a trocar, equipped to deliver insufflation fluid, or by a separate insufflation device, such as an insufflation (veress) needle. Introduction of surgical instruments into the pneumoperitoneum without a substantial loss of insufflation gas is desirable, in order to maintain the pneumoperitoneum. 
     During typical laparoscopic procedures, a surgeon makes three to four small incisions, usually no larger than about twelve millimeters each, which are typically made with the surgical access devices themselves, often using a separate inserter or obturator placed therein. Following insertion, the obturator is removed, and the trocar allows access for instruments to be inserted into the abdominal cavity. Typical trocars provide a pathway to insufflate the abdominal cavity, so that the surgeon has an open interior space in which to work. 
     The trocar must also provide a way to maintain the pressure within the cavity by sealing between the trocar and the surgical instrument being used, while still allowing at least a minimum amount of freedom of movement for the surgical instruments. Such instruments can include, for example, scissors, grasping instruments, and occluding instruments, cauterizing units, cameras, light sources and other surgical instruments. Sealing elements or mechanisms are typically provided on trocars to prevent the escape of insufflation gas from the abdominal cavity. These sealing mechanisms often comprise a duckbill-type valve made of a relatively pliable material, to seal around an outer surface of surgical instruments passing through the trocar. 
     SurgiQuest, Inc., a wholly owned subsidiary of ConMed Corporation has developed unique gas sealed surgical access devices that permit ready access to an insufflated surgical cavity without the need for conventional mechanical valve seals, as described, for example, in U.S. Pat. Nos. 7,854,724 and 8,795,223. These devices are constructed from several nested components including an inner tubular body portion and a coaxial outer tubular body portion. The inner tubular body portion defines a central lumen for introducing conventional laparoscopic or endoscopic surgical instruments to the surgical cavity of a patient and the outer tubular body portion defines an annular lumen surrounding the inner tubular body portion for delivering insufflation gas to the surgical cavity of the patient and for facilitating periodic sensing of abdominal pressure. 
     SurgiQuest has also developed multimodal surgical gas delivery systems for use with the unique gas sealed access devices described above. These gas delivery systems, which are disclosed for example in U.S. Pat. Nos. 9,199,047 and 9,375,539 have a first mode of operation for providing gas sealed access to a body cavity, a second mode of operation for performing smoke evacuation from the body cavity, and a third mode of operation for providing insufflation gas to the body cavity. 
     In the prior art SurgiQuest gas delivery system, the delivery or outflow of insufflation gas to the body cavity is controlled by solenoid valves, which have certain limitations with respect to the ability to control gas flow rates dynamically. For example, a solenoid valve with a 6 mm orifice has two flow states: zero and the 6 mm orifice flow as a function of the differential pressure. However, a 6 mm orifice proportional valve has an infinite number of intermediate flow settings, or equivalent orifice diameters. 
     Since flow is a function of the square of the orifice diameter, the additional intermediate valve positions of a proportional valve provide fine control beyond a simple linear relationship, as well as the ability to achieve stable flow rates at lower pressure, reduce pressure oscillation and eliminate pneumatic hammer. Furthermore, the first 10% of valve opening, or an effective orifice diameter of 0.6 mm, modulates one percent (10% 2 ) of full-open flow; which could be favorable in pediatric applications. 
     SUMMARY OF THE DISCLOSURE 
     The subject application is directed to a new and useful low pressure manifold assembly for a multi-modal surgical gas delivery system, which is configured for facilitating insufflation during a laparoscopic surgical procedure. The low pressure manifold assembly includes a manifold body having an inlet port for receiving insufflation gas from a gas source by way of a high pressure regulator, a first outlet port for delivering insufflation gas to a first access port and a second outlet port for delivering insufflation gas to a second access port. In accordance with a preferred embodiment of the subject invention, the first access port is a valve sealed access port and the second access port in a gas sealed access port. 
     The manifold assembly further incudes a first outlet line valve operatively associated with the first outlet port of the manifold body, wherein the first outlet line valve includes an electro-mechanical valve actuator for dynamically controlling the flow of insufflation gas to the first access port, and a second outlet line valve operatively associated with the second outlet port of the manifold body, wherein the second outlet line valve includes an electro-mechanical valve actuator for dynamically controlling the flow of insufflation gas to the second access port. 
     The manifold body further includes an exhaust port for venting gas to atmosphere, wherein a ventilation exhaust valve is operatively associated with the exhaust port. The ventilation exhaust valve includes an electro-mechanical valve actuator for dynamically controlling the venting of gas from the exhaust port. The manifold body also includes a safety vent port for releasing gas to atmosphere, and a low pressure safety valve is operatively associated with the safety vent port. Preferably, the low pressure safety valve is a mechanical valve for controlling the release of gas from the safety vent port to limit a maximum intermediate pressure within the manifold assembly in the event of a power interruption, a pressure controller malfunction or if another valve sticks in an open position. 
     The manifold body also includes a primary proportional valve located upstream from the first and second outlet line valves. The primary proportional valve includes an electro-mechanical valve actuator for dynamically controlling the flow of insufflation gas to the first and second outlet line valves. The manifold body further includes a communication port for communicating with a pair of blocking valves that are located remote from the manifold assembly. A blocking valve pilot is operatively associated with the communication port, located upstream from the primary proportional valve. The blocking valve pilot includes an electro-mechanical valve actuator for dynamically controlling a flow of gas therethrough. 
     In one embodiment of the manifold assembly, each electro-mechanical valve actuator is configured as a motorized linear actuator, which includes a respective rack and pinion mechanism. Preferably, each rack and pinion mechanism includes a horizontal actuation shaft, a horizontal drive rack gear operatively associated with the horizontal actuation shaft, a rotatable drive pinion gear driven by the horizontal drive rack gear, and a vertical driven rack gear driven by the driven pinon gear and operatively associated with a spring-loaded vertical valve stem. Each horizontal drive rack gear is mounted to translate along a first horizontal axis, and each rotatable driven pinion gear is mounted to rotate about a second horizontal axis that extends perpendicular to the first horizontal axis. 
     In another embodiment of the manifold assembly, each electro-mechanical valve actuator is a motorized rotary actuator, which includes a reduction gear assembly operatively associated with a spring-loaded vertical valve stem. In yet another embodiment of the manifold assembly, each electro-mechanical valve actuator is a motorized rotary actuator, which includes an axial drive screw operatively associated with a spring-loaded vertical valve stem. 
     The manifold body also includes a first patient pressure sensor located downstream from the first outlet line valve and a second patient pressure sensor located downstream from the second outlet line valve for measuring abdominal pressure. In addition, the manifold body includes a first and second pressure sensors located upstream from the outlet line valves, which are associated with a venturi to measure a pressure differential used to infer a total gas flow rate from the manifold to the patient&#39;s body cavity. The manifold body also includes a pressure sensor downstream from the primary proportional valve and upstream from the outlet line valves. 
     These and other features of the manifold assembly of the subject invention will become more readily apparent to those having ordinary skill in the art to which the subject invention appertains from the detailed description of the preferred embodiments taken in conjunction with the following brief description of the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that those skilled in the art will readily understand how to make and use the gas delivery system and method of the subject invention without undue experimentation, preferred embodiments thereof will be described in detail herein below with reference to the figures wherein: 
         FIG. 1  is a schematic diagram of the multi-modal gas delivery system of the subject invention, which includes a gaseous sealing manifold for communicating with a gas sealed access port and a low pressure insufflation manifold for communicating with the gas sealed access port and with a valve sealed access port; 
         FIG. 2  is a perspective view of the insufflation manifold assembly for use in the gas delivery system shown in  FIG. 1 , which includes a plurality of motorized linear valve actuators; 
         FIG. 3  is a right side elevational view of the insufflation manifold assembly shown in  FIG. 2 ; 
         FIG. 4  is a left side elevational view of the insufflation manifold assembly shown in  FIG. 2 ; 
         FIG. 5  is a front elevational view of the insufflation manifold assembly shown in  FIG. 2 ; 
         FIG. 6  is a rear elevational view of the insufflation manifold assembly shown in  FIG. 2 ; 
         FIG. 7  is a cross-sectional view taken along line  7 - 7  of  FIG. 3 ; 
         FIG. 8  is a cross-sectional view taken along line  8 - 8  of  FIG. 3 ; 
         FIG. 9  is a cross-sectional view taken along line  9 - 9  of  FIG. 5 ; 
         FIG. 10  is a cross-sectional view taken along line  10 - 10  of  FIG. 5 ; 
         FIG. 11  is a perspective view of another insufflation manifold assembly for use in the gas delivery system of  FIG. 1 , which includes a plurality of motorized rotary valve actuators; 
         FIGS. 12-14  are related views of an exemplary motorized rotary valve actuator shown in  FIG. 11 , which includes a stepper motor and an axial drive screw, wherein  FIG. 12  is an elevational view of the rotary actuator,  FIG. 13  is a cross-sectional view of the rotary actuator taken along line  13 - 13  of  FIG. 12 , and  FIG. 14  is a perspective view of the rotary actuator; and 
         FIGS. 15-17  are related views of another motorized rotary valve actuator that includes a stepper motor and a reduction gear assembly, wherein  FIG. 15  is an elevational view of the rotary actuator,  FIG. 16  is a cross-sectional view of the rotary actuator taken along line  16 - 16  of  FIG. 15 , and  FIG. 17  is a perspective view of the rotary actuator. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings wherein like reference numerals identify similar structural elements and features of the subject invention, there is illustrated in  FIG. 1  a new and useful multi-modal surgical gas delivery system  10  that is adapted and configured for gas sealed insufflation, recirculation and smoke evacuation during an endoscopic or laparoscopic surgical procedure. The multi-modal surgical gas delivery system  10  of the subject invention includes a gaseous sealing manifold  110  for communicating with a gas sealed access port  20  and an insufflation manifold  210  for communicating with the gas sealed access port  20  and with a valve sealed access port  30 . 
     The gas sealed access port  20  is of the type disclosed in commonly assigned U.S. Pat. No. 8,795,223, which is incorporated herein by reference. The gas sealed access port  20  is adapted and configured to provide gas sealed instrument access to a body cavity, while maintaining a stable pressure within the body cavity (e.g., a stable pneumoperitoneum in the peritoneal or abdominal cavity). In contrast, the valve sealed access port  30  is a conventional or standard trocar, for providing access to a body cavity through a mechanical valve seal, such as, for example, a duckbill seal, septum seal or the like. Depending upon the requirements of a particular surgical procedure, the multi-modal gas delivery system  10  can be utilized with either the gas sealed access port  20 , the valve sealed access port  30  or with both access ports  20 ,  30  at the same time. 
     The gas delivery system  10  further includes a compressor or positive pressure pump  40  for recirculating surgical gas through the gas sealed access port  20  by way of the gaseous sealing manifold  110 . The compressor  40  is preferably driven by a brushless DC (direct-current) motor, which can be advantageously controlled to adjust gas pressure and flow rates within the gas delivery system  10 , as disclosed for example in commonly assigned U.S. Pat. No. 10,702,306, which is incorporated herein by reference. Alternatively, the compressor  40  can be driven by an AC motor, but a DC motor will be relatively smaller and lighter, and therefore more advantageous from a manufacturing standpoint. 
     An intercooler and/or condenser  50  is operatively associated with the compressor  40  for cooling or otherwise conditioning gas recirculating through the gaseous sealing manifold  110 . A UVC irradiator  52  is operatively associated with the intercooler or condenser  50  for sterilizing gas recirculating through the internal flow passages  54  formed therein by way of the compressor  40 . In addition, the UVC irradiator  52  is intended to sterilize the interior surfaces of the gas conduits or flow passages  54  through which the gas flows within the intercooler/condenser  50 . 
     The UVC irradiator preferably includes at least one LED light source or a florescent light source that is adapted and configured to generate UVC radiation at a wavelength of about between 240-350 nm, and preferably about 265 nm. This ultraviolet light at such a wavelength can sterilize viral, bacterial and microbial bodies within the gas conduits of the system, and can reduce coronavirus including SARS-COV-2. 
     Preferably, compressor  40 , intercooler/condenser  50 , gaseous sealing manifold  110  and insufflation manifold  210  are all enclosed within a common housing, which includes a graphical user interface and control electronics, as disclosed for example in commonly assigned U.S. Pat. No. 9,199,047, which is incorporated herein by reference. 
     The gas delivery system  10  further includes a surgical gas source  60  that communicates with the gaseous sealing manifold  110  and the insufflation manifold  210 . The gas source  60  can be a local pressure vessel or a remote supply tank associated with a hospital or healthcare facility. Preferably, gas from the surgical gas source  60  flows through a high pressure regulator  65  and a gas heater  70  before it is delivered to the gaseous sealing manifold  110  and the insufflation manifold  210 . Preferably, the high pressure regulator  65  and the gas heater  70  are also enclosed with the compressor  40 , intercooler  50 , gaseous sealing manifold  110  and insufflation manifold  210  in the common housing. 
     The gas delivery system  10  further includes a first outlet line valve (OLV1)  212  that is operatively associated with the insufflation manifold  210  for controlling a flow of insufflation gas to the valve sealed access port  30  and a second outlet line valve (OLV2)  214  that is operatively associated with the insufflation manifold  210  for controlling a flow of insufflation gas to the gas sealed access port  20 . 
     In accordance with a preferred embodiment of the subject invention, the first and second outlet line valves  212 ,  214  of insufflation manifold  210  are proportional valves that are configured to dynamically alter or otherwise control the outflow of insufflation gas to the access ports  20 ,  30  to match volume fluctuations that may arise in a patient&#39;s body cavity as they occur. The first and second proportional outlet line valves  212 ,  214  provide the gas delivery system  10  with fine control of insufflation gas flow rate to achieve stable flow rates at lower pressure, reduce pressure oscillation and eliminate pneumatic hammer. 
     Because the first and second proportional outlet line valves  212 ,  214  are proximal to the patient where flow friction losses are relatively low, the gas delivery system  10  is able to measure peritoneal pressures accurately. Moreover, the use of proportional outlet line valves for this purpose is uniquely possible here, because there is constant gas recirculation throughout the gas delivery system  10 , either by way of closed loop smoke evacuation or by way of the gas sealed access port  20 . 
     Proportional valves allow for infinitely variable gas flow adjustment between a minimum flow state and a maximum flow state. Given that some volume changes in a patient&#39;s body cavity, such as breathing, are expected and consistent, by employing proportional outlet line valves, the insufflation manifold  210  is able to dynamically alter the gas flow to the body cavity to inverse the expected volume changes, resulting in a neutral effect on the pressure inside the cavity. 
     An additional benefit of using proportional valves for controlling the outflow of insufflation gas from manifold  210  is a reduction in response time, as compared to that of a solenoid valve. A solenoid valve operates by applying energy to coils, which produces an electromagnetic force that moves a piston. However, the energizing of the coils takes some amount of time, introducing a delay between a commanded action and the physical movement of the piston. In contrast, proportional valves, as employed in the gas delivery system  10  of the subject invention, do not have an energization delay in general, and so they have an improved response time as compared to solenoid valves. 
     The insufflation manifold  210  further includes a first patient pressure sensor (PWS1)  222  downstream from the first outlet line valve  212  and a second patient pressure sensor (PWS1)  224  downstream from the second outlet line valve  214 . These two patient pressure sensors are used to measure abdominal pressure to control outlet line valves  212 ,  214 , respectively. Two other pressure sensors are located upstream from the outlet line valves  212 ,  214 , and are labeled as DPS1 and DPS2. These two pressure sensors are situated within a venturi to measure a pressure differential that is used to infer a total gas flow rate from the insufflation manifold  210  to the patient&#39;s body cavity. 
     A primary proportional valve (PRV)  216  is also operatively associated with insufflation manifold  210  and it is located upstream from the first and second outlet line valves  212 ,  214  to control the flow of insufflation gas to the first and second outlet line valves  212 ,  214 . Proportional valve  216  functions to maintain an intermediate pressure within the insufflation manifold  210  (as the central node in the LPU) at a constant pressure between 1 and 80 mmHg, dependent on the system operating mode. The opening of PRV  216  can be indirectly initiated by any of the following actions: patient respiration, gas leakage downstream of PRV  216 , or the opening of the safety valve LSV  227  or ventilation valve VEV  228 , i.e. any event that causes an intermediate pressure to drop. In the system. LSV  227  and VEV  228  are described in more detail below. 
     The gaseous sealing manifold  110  also includes a high pressure gas fill valve (GFV)  112  that is operatively associated with an outlet side of the compressor  40 . GFV  112  is adapted and configured to control gas delivered into the gaseous sealing manifold  110  from the source of surgical gas  60 . Preferably, the gas fill valve  112  is a proportional valve that is able to dynamically control surgical gas delivered into the gaseous sealing manifold  110 . 
     The gaseous sealing manifold  110  also includes a smoke evacuation valve (SEV)  114  that is operatively associated with an outlet side of the compressor  40  for dynamically controlling gas flow between the gaseous sealing manifold  110  and the insufflation manifold  210  under certain operating conditions, such as, for example, when the gas delivery device  10  is operating in a smoke evacuation mode. Preferably, the smoke evacuation valve  114  is a proportional valve. 
     A bypass valve (SPV)  116  is positioned between an outlet side of the compressor  40  and an inlet side of the compressor  40  for controlling gas flow within the gaseous sealing manifold  110  under certain operating conditions. Preferably, the bypass valve  116  is a proportional valve, which is variably opened to establish and control the gaseous seal generated within gas sealed access port  20 . Moreover, bypass valve  116  controls gas flow rate to the gaseous seal using feedback from pressure sensors  122 ,  124 , described in further detail below. 
     The gaseous sealing manifold  110  also includes an air ventilation valve (AVV)  118 , which is operatively associated with an inlet side of the compressor  40  for controlling the entrainment of atmospheric air into the system  10  under certain operating conditions. For example, AVV  118  will permit the introduction of atmospheric air into the gaseous sealing circuit to increase the air mass (i.e., the standard volume) within the circuit. The thermodynamics of clinical use conditions can cause a loss of standard volume within the gas circuit. The ventilation valve  118  permits the gas delivery system  10  to make up for this lost volume, in order to ensure that pump pressure and flow rates are sufficient to maintain the gaseous seal within the gas sealed access port  20 . The ventilation valve  118  can also be opened to reduce the vacuum side pressure in the gas seal circuit. 
     An overpressure relief valve (ORV)  120  is operatively associated with an outlet side of the compressor  40  for controlling a release of gas from the system  10  to atmosphere under certain operating conditions. Preferably, the overpressure relief valve  120  is a proportional valve that is opened to reduce the positively pressurized side of the gas seal circuit, especially in the event of an emergency, such as a loss of power to the gas delivery system  10 . The normally open configuration of relief valve  120  reduces the risk of over-pressurization of the patient cavity upon loss of power to that valve. 
     A first pressure sensor (RLS)  122  is operatively associated with an inlet side of the compressor  40  and a second pressure sensor (PLS)  124  is operatively associated with an outlet side of the compressor  40 . These pressure sensors  122 ,  124  are situated to have unobstructed and minimally restricted commutation with the patient&#39;s abdominal cavity in order to continuously and accurately measure cavity pressure. The signals from these two pressure sensors  122 ,  124  are employed by a controller of the gas delivery system  10  to modulate the opening of the two outlet line valves  212  and  214 , to control the patient cavity pressure. 
     In addition, the gaseous sealing manifold  110  includes a gas quality sensor  126  that is operatively associated with an outlet side of the compressor  40 . The gas quality sensor monitors the level of oxygen in the recirculation circuit, which corresponds to a concentration of CO2 in the body cavity of a patient, as disclosed in U.S. Pat. No. 9,199,047. 
     A first blocking valve (BV1)  132  is operatively associated with an outlet flow path of the gaseous sealing manifold  110  and a second blocking valve (BV2)  134  is operatively associated with an inlet flow path to the gaseous sealing manifold  110 . The blocking valves  132 ,  134  are employed during a self-test prior to a surgical procedure, as disclosed in U.S. Pat. No. 9,199,047. It is envisioned that the first and second blocking valves  132 ,  134  could be are mechanically actuated or pneumatically actuated. 
     A first filter element  142  is positioned downstream from the first blocking valve  132  for filtering pressurized gas flowing from the compressor  40  to the gas sealed access port  20 , and a second filter element  144  is positioned upstream from the second first blocking valve  134  for filtering gas returning to the compressor  40  from the gas sealed access port  20 . Preferably, the filter elements  142 ,  144  are housed within a common filter cartridge, as disclosed for example in U.S. Pat. No. 9,199,047. 
     The first and second blocking valves  132 ,  134  communicate with a blocking valve pilot (BVP)  226  that is included within with the insufflation manifold  210 . Preferably, the blocking valve pilot  226  is a solenoid valve. It is envisioned that BVP  226  could be fed from the compressor outlet as shown or from a gas source such of surgical gas or air. The insufflation manifold  110  further includes a pressure sensor (PMS)  225  located downstream from the primary proportional valve  216  and upstream from the outlet line valves  212 ,  214 . The two outlet line valves are opened to introduce insufflation gas to the patient&#39;s body cavity by way of the access ports  23 ,  30 . This introduction of gas has the effect of increasing pressure within the body cavity. Additionally, the outlet line valves  212 ,  214  can be opened in conjunction with air ventilation valve  228  to release gas from the body cavity, having the effect of desufflation and reduction of cavity pressure. 
     The insufflation manifold  210  further includes a low pressure safety valve (LSV)  227  downstream from the primary proportional valve  216  and upstream from the first and second outlet line valves  212 ,  214  for controlling a release of gas from the system  10  to atmosphere under certain operating conditions. LSV  227  is a purely mechanical valve that functions to limit the maximum intermediate pressure within the manifold  210  or LPU (Low Pressure Unit) in the event of a power interruption, a pressure controller malfunction or if a valve located upstream from the LSV sticks in an open position. 
     In addition, a ventilation exhaust valve (VEV)  228  is positioned downstream from the primary proportional valve  216  and upstream from the outlet line valves  212 ,  214  for controlling a release of gas from the system  10  to atmosphere under certain operating conditions. The ventilation exhaust valve  228  is a preferably a proportional valve that is opened to de-sufflate or otherwise reduce patient cavity pressure. Additionally, VEV  228  can be opened to reduce intermediate pressure within the LPU. 
     A filter element  242  is positioned downstream from the first outlet line valve  212  for filtering insufflation gas flowing from the insufflation manifold  210  to the valve sealed access port  30 . Another filter element  244  is positioned downstream from the second outlet line valve  224  for filtering insulation gas flowing from the insufflation manifold  210  to the gas sealed access port  20 . Preferably, filter element  244  is housed with filter elements  142  and  144  in a common filter cartridge, while filter element  242  is separately located. 
     Referring now to  FIG. 2 , there is illustrated a low pressure insufflation manifold assembly constructed in accordance with a preferred embodiment of the subject invention and designated generally by reference numeral  310  which is adapted and configured for use in the gas delivery system  10  illustrated in  FIG. 1 . The insufflation manifold assembly  310  is designed as a compact, readily serviceable and replaceable modular unit. It includes a manifold body  305  having an inlet port  320  for receiving insufflation gas (i.e., CO2 at 2.2 bar) from a gas source  60  by way of a high pressure regulator  65 , as shown in  FIG. 1 . 
     The manifold body  305  also includes a first outlet port  330  for delivering insufflation gas to a first access port (i.e., the valve sealed access port  30  by way of filter element  242  as shown in  FIG. 1 ) and a second outlet port  340  for delivering insufflation gas to a second access port (i.e., the gas sealed access port  30  by way of filter element  244  as shown in  FIG. 1 ). 
     As shown in  FIGS. 2 through 6 , the manifold body  305  also includes an inlet port  325  for receiving pressurized gas (i.e., compressor discharge) from the gas sealed manifold  110  shown in  FIG. 1 , by way of the smoke evacuation valve (SEV)  114 , under certain operating conditions. The location of the inlet port  325  can be moved to a different positon on the manifold body  305 , for example, a plugged port location downstream from DPS1, DPS2. 
     The manifold body  305  further includes a first exhaust/vent port  335  venting to atmosphere, which communicates with the ventilation valve (VEV)  228  (see  FIGS. 2 and 10 ), and a second exhaust/vent port  337  venting to atmosphere, which communicates with the low pressure safety valve (LSV)  227  (see  FIG. 10 ). As best seen in  FIG. 10 , the low pressure safety valve  227  is a mechanical valve for controlling the release of gas from the safety exhaust/vent port  337  to limit a maximum intermediate pressure within the manifold assembly in the event of a power interruption, a pressure controller malfunction or if another valve sticks in an open position. The mechanical safety valve  227  includes a spring biased valve member  247  that will open when intermediate pressure exceeds a manually adjustable preset pressure. This will limit patient pressure to no more that the preset pressure in the event upon a control malfunction or loss of power. In such an instance, gas will be released through the lower vent port  337  formed in the support base  337  of safety valve  227 . 
     Manifold body  30  also includes a port  337  facilitating communication between the blocking valve pilot valve  226  and the blocking valves  132  (BV1),  134  (BV2) remote from the insufflation manifold assembly  310 . The manifold body  305  further includes sensor ports  422 ,  424  that communicate with patient pressure sensors  222  (PWS1) and  224  (PWS2), respectively. In addition, the manifold body  305  includes sensor ports  426 , 428  that communicate with the pressure differential sensors DPS1 and DPS2. Another sensor port  425  is provided on manifold body  305  for communicating with the intermediate pressure sensor  225  (PMS) located downstream from the primary proportional valve  216  (PRV). 
     As best seen in  FIGS. 8 through 10 , the manifold body  305  defines a series of interconnected internal drilled passageways that facilitate the flow of insufflation gas and air between and among the various control valves and sensors of the insufflation manifold assembly  310 . Those skilled in the art will readily appreciate that the arrangement and location of these passageways within the manifold body  305  could vary by design and therefore should not be considered as a limitation on the scope of the subject invention. 
     Referring now to  FIGS. 7 through 10 , each motorized linear actuator ( 312 ,  314 ,  315 ,  316 ,  318 ) includes a respective rack and pinion mechanism to effectuate precise dynamic control of a respective valve. Each rack and pinion mechanism includes a respective horizontal actuation shaft ( 352 ,  354 ,  355 ,  356 ,  358 ) and a respective corresponding horizontal drive rack gear ( 362 ,  364 ,  365 ,  366 ,  368 ). In addition, each motorized linear actuator ( 312 ,  314 ,  315 ,  316 ,  318 ) includes a rotatable drive pinion gear ( 372 ,  374 ,  375 ,  376 ,  378 ) that is driven by the horizontal drive rack gear ( 362 ,  364 ,  365 ,  366 ,  368 ), and a vertical driven rack gear ( 382 ,  384 ,  385 ,  386 ,  388 ) that is driven by the driven pinon gear ( 372 ,  374 ,  375 ,  376 ,  378 ) and operatively associated with a spring-loaded vertical valve stem ( 392 ,  394 ,  395 ,  396 ,  398 ). Each horizontal drive rack gear ( 362 ,  364 ,  365 ,  366 ,  368 ) is mounted to translate along a first horizontal axis, and each rotatable driven pinion gear ( 372 ,  374 ,  375 ,  376 ,  378 ) is mounted to rotate about a second horizontal axis that extends perpendicular to the first horizontal axis. 
     In use, upon receiving a command from a controller of gas delivery system  10 , linear movement of a horizontal actuation shaft (right or left) will cause corresponding liner movement of an associated horizontal gear rack (right or left), which will rotate a corresponding pinion gear (clockwise or counter-clockwise). That pinon gear will then move an associated vertical drive rack (up or down), which in turn will control the upward or downward movement of a corresponding valve stem ( 392 ,  394 ,  395 ,  396 ,  398 ) of a control valve ( 212  (OLV1),  214  (OLV2),  226  (BVP),  216  (PRV),  228  (VEV)). 
     The five motorized linear actuators ( 312 ,  314 ,  315 ,  316  and  318 ) are arranged in two side-by-side groups on manifold body  305 . More particularly, the linear actuator  312  of the OLV1 valve  212  and the linear actuator  315  of the BVP valve  226  are grouped together within a first housing  432 . And, the linear actuator  314  of the OLV2 valve  214 , the linear actuator  316  of the PRV valve  216  and the linear actuator  318  of the VEV valve  228  are ganged together within a second housing  442 . 
     Front and rear upper transverse spacer rods  434  and  436  provide structural rigidity to the first housing  432 , while front and rear upper transverse spacer rods  444  and  446  provide structural rigidity to the second housing  442 . Those skilled in the art will appreciate from the figures that the flat ribbon cables associated with each of the linear actuators ( 312 ,  314 ,  315 ,  316  and  318 ) extend to a controller of the gas delivery system  10  which delivers power and control signals to the five motorized actuators. 
     Referring now to  FIG. 11 , there illustrated another low pressure insufflation manifold assembly constructed in accordance with a preferred embodiment of the subject invention and designated generally by reference numeral  510  which is adapted and configured for use in the gas delivery system  10  illustrated in  FIG. 1 . Manifold assembly  510  is substantially similar to manifold assembly  310  shown in  FIG. 2 , in that it includes the same proportional control valves for dynamically controlling gas flow (i.e., OLV1, OLV2, BVP, PRV, VEV), but in this embodiment of the subject invention, these proportional control valves have respective motorized rotary actuators  500 , rather the than motorized linear actuators ( 312 ,  314 ,  315 ,  316 ,  318 ) described above. 
     More particularly, as shown in  FIGS. 12 through 14 , each motorized rotary actuator  500  includes an axial drive screw  520  that is supported for vertical translation within a housing  522  driven by a DC rotary stepper motor  524 . In each rotary actuator, the axial drive screw  520  is operatively associated with a spring-loaded vertical valve stem  526  associated with a respective one of the five control valves  212 ,  214 ,  226 ,  216 ,  228  depicted in  FIG. 1 . In use, rotation of the drive screw  520  causes corresponding vertical movement of the valve stem  526  to dynamically adjust the amount of gas flowing through the associated control valve. 
     Alternatively, as shown in  FIGS. 15 through 17  a motorized rotary actuator  600  may be employed in gaseous sealing manifold assembly  510  for dynamically controlling gas flow, each of which includes a reduction gear assembly  625  that is supported within a housing  622  driven by a DC rotary stepper motor  624 . The reduction gear assembly reduces the torque generated by the stepper motor. In each rotary actuator, the reduction gear assembly  625  is operatively associated with a drive screw  620  and a spring-loaded vertical valve stem  626  connected thereto. In use, actuation of the reduction gear assembly causes corresponding vertical movement of the drive screw  620  and attached valve stem  626  to dynamically adjust the amount of gas flowing through the associated control valve (i.e.,  212 ,  214 ,  226 ,  216 ,  228 ). 
     While the gas delivery system of the subject disclosure has been shown and described with reference to preferred embodiments, those skilled in the art will readily appreciate that changes and/or modifications may be made thereto without departing from the scope of the subject disclosure.