30 results about "Perfusion rate" patented technology

The present invention addresses the need to improve the yields of viral vectors when grown in cell culture systems. In particular, it has been demonstrated that for adenovirus, the use of low-medium perfusion rates in an attached cell culture system provides for improved yields. In other embodiments, the inventors have shown that there is improved Ad-p53 production with cells grown in serum-free conditions, and in particular in serum-free suspension culture. Also important to the increase of yields is the use of detergent lysis. Combination of these aspects of the invention permits purification of virus by a single chromatography step that results in purified virus of the same quality as preparations from double CsCl banding using an ultracentrifuge.

A method and apparatus for noninvasive glucose measurement measures glucose indirectly from the natural response of tissue to variations in analyte concentration. The indirect measurement method utilizes factors affected by or correlated with the concentration of glucose, such as refractive index, electrolyte distribution or tissue scattering. Measurement reliability is greatly improved by stabilizing optical properties of the tissue at the measurement site, thus blood perfusion rates at the sample site are regulated. Perfusion is monitored and stabilized by spectroscopically measuring a control parameter, such as skin temperature, that directly affects perfusion. The control parameter is maintained in a range about a set point, thus stabilizing perfusion. Skin temperature is controlled using a variety of means, including the use of active heating and cooling elements, passive devices, such as thermal wraps, and through the use of a heated coupling medium having favorable heat transfer properties.

The present invention addresses the need to improve the yields of viral vectors when grown in cell culture systems. In particular, it has been demonstrated that for adenovirus, the use of low-medium perfusion rates in an attached cell culture system provides for improved yields. In other embodiments, the inventors have shown that there is improved Ad-p53 production with cells grown in serum-free conditions, and in particular in serum-free suspension culture. Also important to the increase of yields is the use of detergent lysis. Combination of these aspects of the invention permits purification of virus by a single chromatography step that results in purified virus of the same quality as preparations from double CsCl banding using an ultracentrifuge.

The present invention relates, in general, to a system for analyzing tissue perfusion using the concentration of indocyanine green and a method of measuring the perfusion rate using the system and, more particularly, to a system for measuring tissue perfusion by injecting indocyanine green into a living body, detecting variation in the concentration of indocyanine green with the passage of time, and analyzing the detected variation, and a method of measuring the perfusion rate using the system. The present invention provides a method of measuring perfusion in a living body, which enables accurate measurement for respective regions in a wide range from a perfusion rate decreased to less than 10% of normal perfusion to a perfusion rate increased to greater than normal perfusion using the above-described mechanism of ICG in a living body, which cannot be conducted using the conventional technology.

The present invention addresses the need to improve the yields of viral vectors when grown in cell culture systems. In particular, it has been demonstrated that for adenovirus, the use of low-medium perfusion rates in an attached cell culture system provides for improved yields. In other embodiments, the inventors have shown that there is improved Ad-p53 production with cells grown in serum-free conditions, and in particular in serum-free suspension culture. Also important to the increase of yields is the use of detergent lysis. Combination of these aspects of the invention permits purification of virus by a single chromatography step that results in purified virus of the same quality as preparations from double CsCl banding using an ultracentrifuge.

A body temperature detector is particularly suited to axillary temperature measurements of adults. The radiation sensor views a target surface area of the body and electronics compute an internal temperature of the body as a function of ambient temperature and sensed surface temperature. The function includes a weighted difference of surface temperature and ambient temperature, the weighting being varied with target temperature to account for varying perfusion rate. Preferably, the coefficient varies from a normal of about 0.13 through a range to include 0.09. The ambient temperature used in the function is assumed at about 80° F. but modified with detector temperature weighted by 20%.

Techniques are provided for use by a pacemaker or other implantable medical device for detecting and tracking trends in cardiopulmonary fluid transfer rates—such as heart-to-lung fluid perfusion rates and lung-to-lymphatic system fluid excretion rates—and for detecting heart failure, dyspnea or other cardiopulmonary conditions. In one example, the device periodically measures transthoracic admittance values. A first exponential time-constant (k1) is determined using curve-fitting from admittance values obtained while the patient is in a sleep posture. Time-constant k1 is representative of the fluid perfusion rate. A second exponential time-constant (k2) is determined based on admittance values obtained while the patient is standing / walking / sitting. The second exponential time-constant (k2) is representative of the fluid excretion rate from the lungs. The device then detects trends, if any, in the time-constants (or in “DC” baseline values) to detect or predict medical conditions such as an imminent heart failure exacerbation.

The invention provides a method for nondestructively measuring thermal parameters of living biological tissue, which is used for determining the thermal parameters of cylindrical living living tissue through three-point surface temperature measurement. The method includes: establishing a two-dimensional Pennes heat transfer model of a cylindrical living body tissue under cylindrical coordinates; using a row-by-row method to solve the temperature change in the cylindrical living body tissue under the interference of a step heat flow or a square wave heat flow; , analyze the correlation between the sensitivity coefficients of thermal parameters and the influence of thermal parameters on temperature changes, and optimize the selection of three measurement points; develop a measurement system for the surface temperature of biological living tissue, and collect temperature transient response data in real time; application improvement Using the Gaussian parameter estimation method, thermal parameters such as thermal conductivity, thermal diffusivity, blood perfusion rate, and volumetric heat capacity of cylindrical biological living tissue are obtained at the same time. The advantage is that it realizes convenient and simple non-destructive measurement.

The invention discloses a technology for producing a recombinant antibody protein through the high density perfusion culture of hybridoma cells. The technology which aims at the metabolic characteristic of the hybridoma cells screens a specific culture component for the perfusion culture, and allows metabolic substrates to be fully supplied in the culture process and the concentration of metabolic byproducts to be simultaneously and effectively reduced, so objects of high efficiency and high yield is reached. In the process control aspect, a specific perfusion rate CSPR perfusion culture calculating model is established to carry out real time calculation on culture parameters, and concentrated medium subsection fed batch is adopted to control the perfusion rate, so important substrates ofglucose and glutamine are supplied and the influence of the byproducts to culture is minimized. The technology which is suitable for the preparation of the production antibody protein through the large scale culture of the hybridoma cells allows a large amount of protein antibodies to be provided in a short time, has the advantages of small scale, low investment, realization of the high efficiency output in a short time, low batch difference, high repeatability, and realization of the production of antibody medicines.

This application relates to the field of biomedical engineering, and discloses a method and system for evaluating the individualized blood perfusion rate of biological tissues. Based on the influence of peripheral blood flow on the thawing process of the target biological tissue after freezing, the calculation of local tissue is established by the principle of boundary convection heat transfer. An algorithm for personalized blood perfusion rate, the method includes: obtaining the surface area of ​​the ice ball formed by freezing the target biological tissue; obtaining the temperature gradient of the ice ball surface and its change over time according to the temperature of the ice ball surface The gradient and its variation with time and the surface area of ​​the ice ball determine the personalized blood perfusion rate around the target biological tissue; output the personalized blood perfusion rate around the target biological tissue.

The present invention relates to cell culture in bioreactors, such as flexible cellbag bioreactors. More closely the invention relates to a method and system for determining the cell density in a bioreactor culture and for controlling the perfusion rate of a suspension culture of cells in a bioreactor, comprising measuring the oxygen uptake of primary mononuclear cells in a non-static bioreactor.

The invention discloses a method for separating and preparing primary hepatocytes, which comprises the following steps: a. Extracorporeal perfusion of the liver: take the isolated animal liver, and first perfuse it with perfusate I at a rate of 300-1000mL / min, The perfusion time is 10-12 minutes; then perfusate with perfusate II, the perfusion rate is 300-1000mL / min, and the perfusion time is 2-3 minutes; finally perfusate with perfusate III, the perfusion rate is 400-1200mL / min, the perfusion time 25‑40 minutes; b. Separation of liver cells: wash the liver treated in step a, collect the liver cell suspension, filter, centrifuge, and collect the precipitate. The method for separating and preparing primary hepatocytes of the present invention can isolate and obtain hepatocytes with high quantity, viability and purity, and has a good application prospect.